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.
17 RiscV ELF riscv*-*-elf
19 *** Changes in GDB 8.1
21 * GDB now supports dynamically creating arbitrary register groups specified
22 in XML target descriptions. This allows for finer grain grouping of
23 registers on systems with a large amount of registers.
25 * The 'ptype' command now accepts a '/o' flag, which prints the
26 offsets and sizes of fields in a struct, like the pahole(1) tool.
28 * New "--readnever" command line option instructs GDB to not read each
29 symbol file's symbolic debug information. This makes startup faster
30 but at the expense of not being able to perform symbolic debugging.
31 This option is intended for use cases where symbolic debugging will
32 not be used, e.g., when you only need to dump the debuggee's core.
34 * GDB now uses the GNU MPFR library, if available, to emulate target
35 floating-point arithmetic during expression evaluation when the target
36 uses different floating-point formats than the host. At least version
37 3.1 of GNU MPFR is required.
39 * GDB now supports access to the guarded-storage-control registers and the
40 software-based guarded-storage broadcast control registers on IBM z14.
42 * On Unix systems, GDB now supports transmitting environment variables
43 that are to be set or unset to GDBserver. These variables will
44 affect the environment to be passed to the remote inferior.
46 To inform GDB of environment variables that are to be transmitted to
47 GDBserver, use the "set environment" command. Only user set
48 environment variables are sent to GDBserver.
50 To inform GDB of environment variables that are to be unset before
51 the remote inferior is started by the GDBserver, use the "unset
54 * Completion improvements
56 ** GDB can now complete function parameters in linespecs and
57 explicit locations without quoting. When setting breakpoints,
58 quoting around functions names to help with TAB-completion is
59 generally no longer necessary. For example, this now completes
62 (gdb) b function(in[TAB]
65 Related, GDB is no longer confused with completing functions in
66 C++ anonymous namespaces:
69 (gdb) b (anonymous namespace)::[TAB][TAB]
70 (anonymous namespace)::a_function()
71 (anonymous namespace)::b_function()
73 ** GDB now has much improved linespec and explicit locations TAB
74 completion support, that better understands what you're
75 completing and offers better suggestions. For example, GDB no
76 longer offers data symbols as possible completions when you're
79 ** GDB now TAB-completes label symbol names.
81 ** The "complete" command now mimics TAB completion accurately.
83 * New command line options (gcore)
86 Dump all memory mappings.
88 * Breakpoints on C++ functions are now set on all scopes by default
90 By default, breakpoints on functions/methods are now interpreted as
91 specifying all functions with the given name ignoring missing
92 leading scopes (namespaces and classes).
94 For example, assuming a C++ program with symbols named:
99 both commands "break func()" and "break B::func()" set a breakpoint
102 You can use the new flag "-qualified" to override this. This makes
103 GDB interpret the specified function name as a complete
104 fully-qualified name instead. For example, using the same C++
105 program, the "break -q B::func" command sets a breakpoint on
106 "B::func", only. A parameter has been added to the Python
107 gdb.Breakpoint constructor to achieve the same result when creating
108 a breakpoint from Python.
110 * Breakpoints on functions marked with C++ ABI tags
112 GDB can now set breakpoints on functions marked with C++ ABI tags
113 (e.g., [abi:cxx11]). See here for a description of ABI tags:
114 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
116 Functions with a C++11 abi tag are demangled/displayed like this:
118 function[abi:cxx11](int)
121 You can now set a breakpoint on such functions simply as if they had
124 (gdb) b function(int)
126 Or if you need to disambiguate between tags, like:
128 (gdb) b function[abi:other_tag](int)
130 Tab completion was adjusted accordingly as well.
134 ** New events gdb.new_inferior, gdb.inferior_deleted, and
135 gdb.new_thread are emitted. See the manual for further
136 description of these.
138 ** A new function, "gdb.rbreak" has been added to the Python API.
139 This function allows the setting of a large number of breakpoints
140 via a regex pattern in Python. See the manual for further details.
142 ** Python breakpoints can now accept explicit locations. See the
143 manual for a further description of this feature.
146 * New features in the GDB remote stub, GDBserver
148 ** GDBserver is now able to start inferior processes with a
149 specified initial working directory.
151 The user can set the desired working directory to be used from
152 GDB using the new "set cwd" command.
154 ** New "--selftest" command line option runs some GDBserver self
155 tests. These self tests are disabled in releases.
157 ** On Unix systems, GDBserver now does globbing expansion and variable
158 substitution in inferior command line arguments.
160 This is done by starting inferiors using a shell, like GDB does.
161 See "set startup-with-shell" in the user manual for how to disable
162 this from GDB when using "target extended-remote". When using
163 "target remote", you can disable the startup with shell by using the
164 new "--no-startup-with-shell" GDBserver command line option.
166 ** On Unix systems, GDBserver now supports receiving environment
167 variables that are to be set or unset from GDB. These variables
168 will affect the environment to be passed to the inferior.
170 * When catching an Ada exception raised with a message, GDB now prints
171 the message in the catchpoint hit notification. In GDB/MI mode, that
172 information is provided as an extra field named "exception-message"
173 in the *stopped notification.
175 * Trait objects can now be inspected When debugging Rust code. This
176 requires compiler support which will appear in Rust 1.24.
180 QEnvironmentHexEncoded
181 Inform GDBserver of an environment variable that is to be passed to
182 the inferior when starting it.
185 Inform GDBserver of an environment variable that is to be unset
186 before starting the remote inferior.
189 Inform GDBserver that the environment should be reset (i.e.,
190 user-set environment variables should be unset).
193 Indicates whether the inferior must be started with a shell or not.
196 Tell GDBserver that the inferior to be started should use a specific
199 * The "maintenance print c-tdesc" command now takes an optional
200 argument which is the file name of XML target description.
202 * The "maintenance selftest" command now takes an optional argument to
203 filter the tests to be run.
205 * The "enable", and "disable" commands now accept a range of
206 breakpoint locations, e.g. "enable 1.3-5".
211 Set and show the current working directory for the inferior.
214 Set and show compilation command used for compiling and injecting code
215 with the 'compile' commands.
217 set debug separate-debug-file
218 show debug separate-debug-file
219 Control the display of debug output about separate debug file search.
221 set dump-excluded-mappings
222 show dump-excluded-mappings
223 Control whether mappings marked with the VM_DONTDUMP flag should be
224 dumped when generating a core file.
227 List the registered selftests.
230 Start the debugged program stopping at the first instruction.
233 Control display of debugging messages related to OpenRISC targets.
235 set|show print type nested-type-limit
236 Set and show the limit of nesting level for nested types that the
237 type printer will show.
239 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
242 * Safer/improved support for debugging with no debug info
244 GDB no longer assumes functions with no debug information return
247 This means that GDB now refuses to call such functions unless you
248 tell it the function's type, by either casting the call to the
249 declared return type, or by casting the function to a function
250 pointer of the right type, and calling that:
252 (gdb) p getenv ("PATH")
253 'getenv' has unknown return type; cast the call to its declared return type
254 (gdb) p (char *) getenv ("PATH")
255 $1 = 0x7fffffffe "/usr/local/bin:/"...
256 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
257 $2 = 0x7fffffffe "/usr/local/bin:/"...
259 Similarly, GDB no longer assumes that global variables with no debug
260 info have type 'int', and refuses to print the variable's value
261 unless you tell it the variable's type:
264 'var' has unknown type; cast it to its declared type
268 * New native configurations
270 FreeBSD/aarch64 aarch64*-*-freebsd*
271 FreeBSD/arm arm*-*-freebsd*
275 FreeBSD/aarch64 aarch64*-*-freebsd*
276 FreeBSD/arm arm*-*-freebsd*
277 OpenRISC ELF or1k*-*-elf
279 * Removed targets and native configurations
281 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
283 *** Changes in GDB 8.0
285 * GDB now supports access to the PKU register on GNU/Linux. The register is
286 added by the Memory Protection Keys for Userspace feature which will be
287 available in future Intel CPUs.
289 * GDB now supports C++11 rvalue references.
293 ** New functions to start, stop and access a running btrace recording.
294 ** Rvalue references are now supported in gdb.Type.
296 * GDB now supports recording and replaying rdrand and rdseed Intel 64
299 * Building GDB and GDBserver now requires a C++11 compiler.
301 For example, GCC 4.8 or later.
303 It is no longer possible to build GDB or GDBserver with a C
304 compiler. The --disable-build-with-cxx configure option has been
307 * Building GDB and GDBserver now requires GNU make >= 3.81.
309 It is no longer supported to build GDB or GDBserver with another
310 implementation of the make program or an earlier version of GNU make.
312 * Native debugging on MS-Windows supports command-line redirection
314 Command-line arguments used for starting programs on MS-Windows can
315 now include redirection symbols supported by native Windows shells,
316 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
317 as "run", "start", and "set args", as well as the corresponding MI
320 * Support for thread names on MS-Windows.
322 GDB now catches and handles the special exception that programs
323 running on MS-Windows use to assign names to threads in the
326 * Support for Java programs compiled with gcj has been removed.
328 * User commands now accept an unlimited number of arguments.
329 Previously, only up to 10 was accepted.
331 * The "eval" command now expands user-defined command arguments.
333 This makes it easier to process a variable number of arguments:
338 eval "print $arg%d", $i
343 * Target descriptions can now describe registers for sparc32 and sparc64.
345 * GDB now supports DWARF version 5 (debug information format).
346 Its .debug_names index is not yet supported.
348 * New native configurations
350 FreeBSD/mips mips*-*-freebsd
354 Synopsys ARC arc*-*-elf32
355 FreeBSD/mips mips*-*-freebsd
357 * Removed targets and native configurations
359 Alpha running FreeBSD alpha*-*-freebsd*
360 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
365 Erases all the flash memory regions reported by the target.
367 maint print arc arc-instruction address
368 Print internal disassembler information about instruction at a given address.
372 set disassembler-options
373 show disassembler-options
374 Controls the passing of target specific information to the disassembler.
375 If it is necessary to specify more than one disassembler option then
376 multiple options can be placed together into a comma separated list.
377 The default value is the empty string. Currently, the only supported
378 targets are ARM, PowerPC and S/390.
383 Erases all the flash memory regions reported by the target. This is
384 equivalent to the CLI command flash-erase.
386 -file-list-shared-libraries
387 List the shared libraries in the program. This is
388 equivalent to the CLI command "info shared".
391 Catchpoints stopping the program when Ada exceptions are
392 handled. This is equivalent to the CLI command "catch handlers".
394 *** Changes in GDB 7.12
396 * GDB and GDBserver now build with a C++ compiler by default.
398 The --enable-build-with-cxx configure option is now enabled by
399 default. One must now explicitly configure with
400 --disable-build-with-cxx in order to build with a C compiler. This
401 option will be removed in a future release.
403 * GDBserver now supports recording btrace without maintaining an active
406 * GDB now supports a negative repeat count in the 'x' command to examine
407 memory backward from the given address. For example:
410 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
411 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
412 (gdb) x/-5i 0x0000000000400580
413 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
414 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
415 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
416 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
417 0x40057b <main(int, char**)+25>:
418 callq 0x400536 <Func1(int, char const*)>
420 * Fortran: Support structures with fields of dynamic types and
421 arrays of dynamic types.
423 * The symbol dumping maintenance commands have new syntax.
424 maint print symbols [-pc address] [--] [filename]
425 maint print symbols [-objfile objfile] [-source source] [--] [filename]
426 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
427 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
428 maint print msymbols [-objfile objfile] [--] [filename]
430 * GDB now supports multibit bitfields and enums in target register
433 * New Python-based convenience function $_as_string(val), which returns
434 the textual representation of a value. This function is especially
435 useful to obtain the text label of an enum value.
437 * Intel MPX bound violation handling.
439 Segmentation faults caused by a Intel MPX boundary violation
440 now display the kind of violation (upper or lower), the memory
441 address accessed and the memory bounds, along with the usual
442 signal received and code location.
446 Program received signal SIGSEGV, Segmentation fault
447 Upper bound violation while accessing address 0x7fffffffc3b3
448 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
449 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
451 * Rust language support.
452 GDB now supports debugging programs written in the Rust programming
453 language. See https://www.rust-lang.org/ for more information about
456 * Support for running interpreters on specified input/output devices
458 GDB now supports a new mechanism that allows frontends to provide
459 fully featured GDB console views, as a better alternative to
460 building such views on top of the "-interpreter-exec console"
461 command. See the new "new-ui" command below. With that command,
462 frontends can now start GDB in the traditional command-line mode
463 running in an embedded terminal emulator widget, and create a
464 separate MI interpreter running on a specified i/o device. In this
465 way, GDB handles line editing, history, tab completion, etc. in the
466 console all by itself, and the GUI uses the separate MI interpreter
467 for its own control and synchronization, invisible to the command
470 * The "catch syscall" command catches groups of related syscalls.
472 The "catch syscall" command now supports catching a group of related
473 syscalls using the 'group:' or 'g:' prefix.
478 skip -gfile file-glob-pattern
479 skip -function function
480 skip -rfunction regular-expression
481 A generalized form of the skip command, with new support for
482 glob-style file names and regular expressions for function names.
483 Additionally, a file spec and a function spec may now be combined.
485 maint info line-table REGEXP
486 Display the contents of GDB's internal line table data struture.
489 Run any GDB unit tests that were compiled in.
492 Start a new user interface instance running INTERP as interpreter,
493 using the TTY file for input/output.
497 ** gdb.Breakpoint objects have a new attribute "pending", which
498 indicates whether the breakpoint is pending.
499 ** Three new breakpoint-related events have been added:
500 gdb.breakpoint_created, gdb.breakpoint_modified, and
501 gdb.breakpoint_deleted.
504 Signal ("set") the given MS-Windows event object. This is used in
505 conjunction with the Windows JIT debugging (AeDebug) support, where
506 the OS suspends a crashing process until a debugger can attach to
507 it. Resuming the crashing process, in order to debug it, is done by
510 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
511 was added in GDBserver, including JIT compiling fast tracepoint's
512 conditional expression bytecode into native code.
514 * Support for various remote target protocols and ROM monitors has
517 target m32rsdi Remote M32R debugging over SDI
518 target mips MIPS remote debugging protocol
519 target pmon PMON ROM monitor
520 target ddb NEC's DDB variant of PMON for Vr4300
521 target rockhopper NEC RockHopper variant of PMON
522 target lsi LSI variant of PMO
524 * Support for tracepoints and fast tracepoints on powerpc-linux,
525 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
526 including JIT compiling fast tracepoint's conditional expression
527 bytecode into native code.
529 * MI async record =record-started now includes the method and format used for
530 recording. For example:
532 =record-started,thread-group="i1",method="btrace",format="bts"
534 * MI async record =thread-selected now includes the frame field. For example:
536 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
540 Andes NDS32 nds32*-*-elf
542 *** Changes in GDB 7.11
544 * GDB now supports debugging kernel-based threads on FreeBSD.
546 * Per-inferior thread numbers
548 Thread numbers are now per inferior instead of global. If you're
549 debugging multiple inferiors, GDB displays thread IDs using a
550 qualified INF_NUM.THR_NUM form. For example:
554 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
555 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
556 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
557 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
559 As consequence, thread numbers as visible in the $_thread
560 convenience variable and in Python's InferiorThread.num attribute
561 are no longer unique between inferiors.
563 GDB now maintains a second thread ID per thread, referred to as the
564 global thread ID, which is the new equivalent of thread numbers in
565 previous releases. See also $_gthread below.
567 For backwards compatibility, MI's thread IDs always refer to global
570 * Commands that accept thread IDs now accept the qualified
571 INF_NUM.THR_NUM form as well. For example:
574 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
577 * In commands that accept a list of thread IDs, you can now refer to
578 all threads of an inferior using a star wildcard. GDB accepts
579 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
580 refer to all threads of the current inferior. For example, "info
583 * You can use "info threads -gid" to display the global thread ID of
586 * The new convenience variable $_gthread holds the global number of
589 * The new convenience variable $_inferior holds the number of the
592 * GDB now displays the ID and name of the thread that hit a breakpoint
593 or received a signal, if your program is multi-threaded. For
596 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
597 Thread 1 "main" received signal SIGINT, Interrupt.
599 * Record btrace now supports non-stop mode.
601 * Support for tracepoints on aarch64-linux was added in GDBserver.
603 * The 'record instruction-history' command now indicates speculative execution
604 when using the Intel Processor Trace recording format.
606 * GDB now allows users to specify explicit locations, bypassing
607 the linespec parser. This feature is also available to GDB/MI
610 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
611 GDB now is able to debug both AArch64 applications and ARM applications
614 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
615 including JIT compiling fast tracepoint's conditional expression bytecode
618 * GDB now supports displaced stepping on AArch64 GNU/Linux.
620 * "info threads", "info inferiors", "info display", "info checkpoints"
621 and "maint info program-spaces" now list the corresponding items in
622 ascending ID order, for consistency with all other "info" commands.
624 * In Ada, the overloads selection menu has been enhanced to display the
625 parameter types and the return types for the matching overloaded subprograms.
629 maint set target-non-stop (on|off|auto)
630 maint show target-non-stop
631 Control whether GDB targets always operate in non-stop mode even if
632 "set non-stop" is "off". The default is "auto", meaning non-stop
633 mode is enabled if supported by the target.
635 maint set bfd-sharing
636 maint show bfd-sharing
637 Control the reuse of bfd objects.
641 Control display of debugging info regarding bfd caching.
645 Control display of debugging info regarding FreeBSD threads.
647 set remote multiprocess-extensions-packet
648 show remote multiprocess-extensions-packet
649 Set/show the use of the remote protocol multiprocess extensions.
651 set remote thread-events
652 show remote thread-events
653 Set/show the use of thread create/exit events.
655 set ada print-signatures on|off
656 show ada print-signatures"
657 Control whether parameter types and return types are displayed in overloads
658 selection menus. It is activaled (@code{on}) by default.
662 Controls the maximum size of memory, in bytes, that GDB will
663 allocate for value contents. Prevents incorrect programs from
664 causing GDB to allocate overly large buffers. Default is 64k.
666 * The "disassemble" command accepts a new modifier: /s.
667 It prints mixed source+disassembly like /m with two differences:
668 - disassembled instructions are now printed in program order, and
669 - and source for all relevant files is now printed.
670 The "/m" option is now considered deprecated: its "source-centric"
671 output hasn't proved useful in practice.
673 * The "record instruction-history" command accepts a new modifier: /s.
674 It behaves exactly like /m and prints mixed source+disassembly.
676 * The "set scheduler-locking" command supports a new mode "replay".
677 It behaves like "off" in record mode and like "on" in replay mode.
679 * Support for various ROM monitors has been removed:
681 target dbug dBUG ROM monitor for Motorola ColdFire
682 target picobug Motorola picobug monitor
683 target dink32 DINK32 ROM monitor for PowerPC
684 target m32r Renesas M32R/D ROM monitor
685 target mon2000 mon2000 ROM monitor
686 target ppcbug PPCBUG ROM monitor for PowerPC
688 * Support for reading/writing memory and extracting values on architectures
689 whose memory is addressable in units of any integral multiple of 8 bits.
692 Allows to break when an Ada exception is handled.
697 Indicates that an exec system call was executed.
699 exec-events feature in qSupported
700 The qSupported packet allows GDB to request support for exec
701 events using the new 'gdbfeature' exec-event, and the qSupported
702 response can contain the corresponding 'stubfeature'. Set and
703 show commands can be used to display whether these features are enabled.
706 Equivalent to interrupting with the ^C character, but works in
709 thread created stop reason (T05 create:...)
710 Indicates that the thread was just created and is stopped at entry.
712 thread exit stop reply (w exitcode;tid)
713 Indicates that the thread has terminated.
716 Enables/disables thread create and exit event reporting. For
717 example, this is used in non-stop mode when GDB stops a set of
718 threads and synchronously waits for the their corresponding stop
719 replies. Without exit events, if one of the threads exits, GDB
720 would hang forever not knowing that it should no longer expect a
721 stop for that same thread.
724 Indicates that there are no resumed threads left in the target (all
725 threads are stopped). The remote stub reports support for this stop
726 reply to GDB's qSupported query.
729 Enables/disables catching syscalls from the inferior process.
730 The remote stub reports support for this packet to GDB's qSupported query.
732 syscall_entry stop reason
733 Indicates that a syscall was just called.
735 syscall_return stop reason
736 Indicates that a syscall just returned.
738 * Extended-remote exec events
740 ** GDB now has support for exec events on extended-remote Linux targets.
741 For such targets with Linux kernels 2.5.46 and later, this enables
742 follow-exec-mode and exec catchpoints.
744 set remote exec-event-feature-packet
745 show remote exec-event-feature-packet
746 Set/show the use of the remote exec event feature.
748 * Thread names in remote protocol
750 The reply to qXfer:threads:read may now include a name attribute for each
753 * Target remote mode fork and exec events
755 ** GDB now has support for fork and exec events on target remote mode
756 Linux targets. For such targets with Linux kernels 2.5.46 and later,
757 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
758 fork and exec catchpoints.
760 * Remote syscall events
762 ** GDB now has support for catch syscall on remote Linux targets,
763 currently enabled on x86/x86_64 architectures.
765 set remote catch-syscall-packet
766 show remote catch-syscall-packet
767 Set/show the use of the remote catch syscall feature.
771 ** The -var-set-format command now accepts the zero-hexadecimal
772 format. It outputs data in hexadecimal format with zero-padding on the
777 ** gdb.InferiorThread objects have a new attribute "global_num",
778 which refers to the thread's global thread ID. The existing
779 "num" attribute now refers to the thread's per-inferior number.
780 See "Per-inferior thread numbers" above.
781 ** gdb.InferiorThread objects have a new attribute "inferior", which
782 is the Inferior object the thread belongs to.
784 *** Changes in GDB 7.10
786 * Support for process record-replay and reverse debugging on aarch64*-linux*
787 targets has been added. GDB now supports recording of A64 instruction set
788 including advance SIMD instructions.
790 * Support for Sun's version of the "stabs" debug file format has been removed.
792 * GDB now honors the content of the file /proc/PID/coredump_filter
793 (PID is the process ID) on GNU/Linux systems. This file can be used
794 to specify the types of memory mappings that will be included in a
795 corefile. For more information, please refer to the manual page of
796 "core(5)". GDB also has a new command: "set use-coredump-filter
797 on|off". It allows to set whether GDB will read the content of the
798 /proc/PID/coredump_filter file when generating a corefile.
800 * The "info os" command on GNU/Linux can now display information on
802 "info os cpus" Listing of all cpus/cores on the system
804 * GDB has two new commands: "set serial parity odd|even|none" and
805 "show serial parity". These allows to set or show parity for the
808 * The "info source" command now displays the producer string if it was
809 present in the debug info. This typically includes the compiler version
810 and may include things like its command line arguments.
812 * The "info dll", an alias of the "info sharedlibrary" command,
813 is now available on all platforms.
815 * Directory names supplied to the "set sysroot" commands may be
816 prefixed with "target:" to tell GDB to access shared libraries from
817 the target system, be it local or remote. This replaces the prefix
818 "remote:". The default sysroot has been changed from "" to
819 "target:". "remote:" is automatically converted to "target:" for
820 backward compatibility.
822 * The system root specified by "set sysroot" will be prepended to the
823 filename of the main executable (if reported to GDB as absolute by
824 the operating system) when starting processes remotely, and when
825 attaching to already-running local or remote processes.
827 * GDB now supports automatic location and retrieval of executable
828 files from remote targets. Remote debugging can now be initiated
829 using only a "target remote" or "target extended-remote" command
830 (no "set sysroot" or "file" commands are required). See "New remote
833 * The "dump" command now supports verilog hex format.
835 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
837 * On GNU/Linux, GDB and gdbserver are now able to access executable
838 and shared library files without a "set sysroot" command when
839 attaching to processes running in different mount namespaces from
840 the debugger. This makes it possible to attach to processes in
841 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
842 See "New remote packets" below.
844 * The "tui reg" command now provides completion for all of the
845 available register groups, including target specific groups.
847 * The HISTSIZE environment variable is no longer read when determining
848 the size of GDB's command history. GDB now instead reads the dedicated
849 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
850 disables truncation of command history. Non-numeric values of GDBHISTSIZE
855 ** Memory ports can now be unbuffered.
859 ** gdb.Objfile objects have a new attribute "username",
860 which is the name of the objfile as specified by the user,
861 without, for example, resolving symlinks.
862 ** You can now write frame unwinders in Python.
863 ** gdb.Type objects have a new method "optimized_out",
864 returning optimized out gdb.Value instance of this type.
865 ** gdb.Value objects have new methods "reference_value" and
866 "const_value" which return a reference to the value and a
867 "const" version of the value respectively.
871 maint print symbol-cache
872 Print the contents of the symbol cache.
874 maint print symbol-cache-statistics
875 Print statistics of symbol cache usage.
877 maint flush-symbol-cache
878 Flush the contents of the symbol cache.
882 Start branch trace recording using Branch Trace Store (BTS) format.
885 Evaluate expression by using the compiler and print result.
889 Explicit commands for enabling and disabling tui mode.
892 set mpx bound on i386 and amd64
893 Support for bound table investigation on Intel MPX enabled applications.
897 Start branch trace recording using Intel Processor Trace format.
900 Print information about branch tracing internals.
902 maint btrace packet-history
903 Print the raw branch tracing data.
905 maint btrace clear-packet-history
906 Discard the stored raw branch tracing data.
909 Discard all branch tracing data. It will be fetched and processed
910 anew by the next "record" command.
915 Renamed from "set debug dwarf2-die".
917 Renamed from "show debug dwarf2-die".
920 Renamed from "set debug dwarf2-read".
921 show debug dwarf-read
922 Renamed from "show debug dwarf2-read".
924 maint set dwarf always-disassemble
925 Renamed from "maint set dwarf2 always-disassemble".
926 maint show dwarf always-disassemble
927 Renamed from "maint show dwarf2 always-disassemble".
929 maint set dwarf max-cache-age
930 Renamed from "maint set dwarf2 max-cache-age".
931 maint show dwarf max-cache-age
932 Renamed from "maint show dwarf2 max-cache-age".
935 show debug dwarf-line
936 Control display of debugging info regarding DWARF line processing.
940 Set the maximum number of candidates to be considered during
941 completion. The default value is 200. This limit allows GDB
942 to avoid generating large completion lists, the computation of
943 which can cause the debugger to become temporarily unresponsive.
945 set history remove-duplicates
946 show history remove-duplicates
947 Control the removal of duplicate history entries.
949 maint set symbol-cache-size
950 maint show symbol-cache-size
951 Control the size of the symbol cache.
953 set|show record btrace bts buffer-size
954 Set and show the size of the ring buffer used for branch tracing in
956 The obtained size may differ from the requested size. Use "info
957 record" to see the obtained buffer size.
959 set debug linux-namespaces
960 show debug linux-namespaces
961 Control display of debugging info regarding Linux namespaces.
963 set|show record btrace pt buffer-size
964 Set and show the size of the ring buffer used for branch tracing in
965 Intel Processor Trace format.
966 The obtained size may differ from the requested size. Use "info
967 record" to see the obtained buffer size.
969 maint set|show btrace pt skip-pad
970 Set and show whether PAD packets are skipped when computing the
973 * The command 'thread apply all' can now support new option '-ascending'
974 to call its specified command for all threads in ascending order.
976 * Python/Guile scripting
978 ** GDB now supports auto-loading of Python/Guile scripts contained in the
979 special section named `.debug_gdb_scripts'.
983 qXfer:btrace-conf:read
984 Return the branch trace configuration for the current thread.
986 Qbtrace-conf:bts:size
987 Set the requested ring buffer size for branch tracing in BTS format.
990 Enable Intel Procesor Trace-based branch tracing for the current
991 process. The remote stub reports support for this packet to GDB's
995 Set the requested ring buffer size for branch tracing in Intel Processor
999 Indicates a memory breakpoint instruction was executed, irrespective
1000 of whether it was GDB that planted the breakpoint or the breakpoint
1001 is hardcoded in the program. This is required for correct non-stop
1005 Indicates the target stopped for a hardware breakpoint. This is
1006 required for correct non-stop mode operation.
1009 Return information about files on the remote system.
1011 qXfer:exec-file:read
1012 Return the full absolute name of the file that was executed to
1013 create a process running on the remote system.
1016 Select the filesystem on which vFile: operations with filename
1017 arguments will operate. This is required for GDB to be able to
1018 access files on remote targets where the remote stub does not
1019 share a common filesystem with the inferior(s).
1022 Indicates that a fork system call was executed.
1025 Indicates that a vfork system call was executed.
1027 vforkdone stop reason
1028 Indicates that a vfork child of the specified process has executed
1029 an exec or exit, allowing the vfork parent to resume execution.
1031 fork-events and vfork-events features in qSupported
1032 The qSupported packet allows GDB to request support for fork and
1033 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1034 and the qSupported response can contain the corresponding
1035 'stubfeatures'. Set and show commands can be used to display
1036 whether these features are enabled.
1038 * Extended-remote fork events
1040 ** GDB now has support for fork events on extended-remote Linux
1041 targets. For targets with Linux kernels 2.5.60 and later, this
1042 enables follow-fork-mode and detach-on-fork for both fork and
1043 vfork, as well as fork and vfork catchpoints.
1045 * The info record command now shows the recording format and the
1046 branch tracing configuration for the current thread when using
1047 the btrace record target.
1048 For the BTS format, it shows the ring buffer size.
1050 * GDB now has support for DTrace USDT (Userland Static Defined
1051 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1053 * GDB now supports access to vector registers on S/390 GNU/Linux
1056 * Removed command line options
1058 -xdb HP-UX XDB compatibility mode.
1060 * Removed targets and native configurations
1062 HP/PA running HP-UX hppa*-*-hpux*
1063 Itanium running HP-UX ia64-*-hpux*
1065 * New configure options
1068 This configure option allows the user to build GDB with support for
1069 Intel Processor Trace (default: auto). This requires libipt.
1071 --with-libipt-prefix=PATH
1072 Specify the path to the version of libipt that GDB should use.
1073 $PATH/include should contain the intel-pt.h header and
1074 $PATH/lib should contain the libipt.so library.
1076 *** Changes in GDB 7.9.1
1080 ** Xmethods can now specify a result type.
1082 *** Changes in GDB 7.9
1084 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1088 ** You can now access frame registers from Python scripts.
1089 ** New attribute 'producer' for gdb.Symtab objects.
1090 ** gdb.Objfile objects have a new attribute "progspace",
1091 which is the gdb.Progspace object of the containing program space.
1092 ** gdb.Objfile objects have a new attribute "owner".
1093 ** gdb.Objfile objects have a new attribute "build_id",
1094 which is the build ID generated when the file was built.
1095 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1096 ** A new event "gdb.clear_objfiles" has been added, triggered when
1097 selecting a new file to debug.
1098 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1099 ** New function gdb.lookup_objfile.
1101 New events which are triggered when GDB modifies the state of the
1104 ** gdb.events.inferior_call_pre: Function call is about to be made.
1105 ** gdb.events.inferior_call_post: Function call has just been made.
1106 ** gdb.events.memory_changed: A memory location has been altered.
1107 ** gdb.events.register_changed: A register has been altered.
1109 * New Python-based convenience functions:
1111 ** $_caller_is(name [, number_of_frames])
1112 ** $_caller_matches(regexp [, number_of_frames])
1113 ** $_any_caller_is(name [, number_of_frames])
1114 ** $_any_caller_matches(regexp [, number_of_frames])
1116 * GDB now supports the compilation and injection of source code into
1117 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1118 to compile the source code to object code, and if successful, inject
1119 and execute that code within the current context of the inferior.
1120 Currently the C language is supported. The commands used to
1121 interface with this new feature are:
1123 compile code [-raw|-r] [--] [source code]
1124 compile file [-raw|-r] filename
1128 demangle [-l language] [--] name
1129 Demangle "name" in the specified language, or the current language
1130 if elided. This command is renamed from the "maint demangle" command.
1131 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1132 as "maint demangler-warning".
1134 queue-signal signal-name-or-number
1135 Queue a signal to be delivered to the thread when it is resumed.
1137 add-auto-load-scripts-directory directory
1138 Add entries to the list of directories from which to load auto-loaded
1141 maint print user-registers
1142 List all currently available "user" registers.
1144 compile code [-r|-raw] [--] [source code]
1145 Compile, inject, and execute in the inferior the executable object
1146 code produced by compiling the provided source code.
1148 compile file [-r|-raw] filename
1149 Compile and inject into the inferior the executable object code
1150 produced by compiling the source code stored in the filename
1153 * On resume, GDB now always passes the signal the program had stopped
1154 for to the thread the signal was sent to, even if the user changed
1155 threads before resuming. Previously GDB would often (but not
1156 always) deliver the signal to the thread that happens to be current
1159 * Conversely, the "signal" command now consistently delivers the
1160 requested signal to the current thread. GDB now asks for
1161 confirmation if the program had stopped for a signal and the user
1162 switched threads meanwhile.
1164 * "breakpoint always-inserted" modes "off" and "auto" merged.
1166 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1167 won't remove breakpoints from the target until all threads stop,
1168 even in non-stop mode. The "auto" mode has been removed, and "off"
1169 is now the default mode.
1173 set debug symbol-lookup
1174 show debug symbol-lookup
1175 Control display of debugging info regarding symbol lookup.
1179 ** The -list-thread-groups command outputs an exit-code field for
1180 inferiors that have exited.
1184 MIPS SDE mips*-sde*-elf*
1188 Support for these obsolete configurations has been removed.
1190 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1191 SGI Irix-5.x mips-*-irix5*
1192 SGI Irix-6.x mips-*-irix6*
1193 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1194 VAX running Ultrix vax-*-ultrix*
1196 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1197 and "assf"), have been removed. Use the "sharedlibrary" command, or
1198 its alias "share", instead.
1200 *** Changes in GDB 7.8
1202 * New command line options
1205 This is an alias for the --data-directory option.
1207 * GDB supports printing and modifying of variable length automatic arrays
1208 as specified in ISO C99.
1210 * The ARM simulator now supports instruction level tracing
1211 with or without disassembly.
1215 GDB now has support for scripting using Guile. Whether this is
1216 available is determined at configure time.
1217 Guile version 2.0 or greater is required.
1218 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1220 * New commands (for set/show, see "New options" below)
1224 Invoke CODE by passing it to the Guile interpreter.
1228 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1230 info auto-load guile-scripts [regexp]
1231 Print the list of automatically loaded Guile scripts.
1233 * The source command is now capable of sourcing Guile scripts.
1234 This feature is dependent on the debugger being built with Guile support.
1238 set print symbol-loading (off|brief|full)
1239 show print symbol-loading
1240 Control whether to print informational messages when loading symbol
1241 information for a file. The default is "full", but when debugging
1242 programs with large numbers of shared libraries the amount of output
1243 becomes less useful.
1245 set guile print-stack (none|message|full)
1246 show guile print-stack
1247 Show a stack trace when an error is encountered in a Guile script.
1249 set auto-load guile-scripts (on|off)
1250 show auto-load guile-scripts
1251 Control auto-loading of Guile script files.
1253 maint ada set ignore-descriptive-types (on|off)
1254 maint ada show ignore-descriptive-types
1255 Control whether the debugger should ignore descriptive types in Ada
1256 programs. The default is not to ignore the descriptive types. See
1257 the user manual for more details on descriptive types and the intended
1258 usage of this option.
1260 set auto-connect-native-target
1262 Control whether GDB is allowed to automatically connect to the
1263 native target for the run, attach, etc. commands when not connected
1264 to any target yet. See also "target native" below.
1266 set record btrace replay-memory-access (read-only|read-write)
1267 show record btrace replay-memory-access
1268 Control what memory accesses are allowed during replay.
1270 maint set target-async (on|off)
1271 maint show target-async
1272 This controls whether GDB targets operate in synchronous or
1273 asynchronous mode. Normally the default is asynchronous, if it is
1274 available; but this can be changed to more easily debug problems
1275 occurring only in synchronous mode.
1277 set mi-async (on|off)
1279 Control whether MI asynchronous mode is preferred. This supersedes
1280 "set target-async" of previous GDB versions.
1282 * "set target-async" is deprecated as a CLI option and is now an alias
1283 for "set mi-async" (only puts MI into async mode).
1285 * Background execution commands (e.g., "c&", "s&", etc.) are now
1286 possible ``out of the box'' if the target supports them. Previously
1287 the user would need to explicitly enable the possibility with the
1288 "set target-async on" command.
1290 * New features in the GDB remote stub, GDBserver
1292 ** New option --debug-format=option1[,option2,...] allows one to add
1293 additional text to each output. At present only timestamps
1294 are supported: --debug-format=timestamps.
1295 Timestamps can also be turned on with the
1296 "monitor set debug-format timestamps" command from GDB.
1298 * The 'record instruction-history' command now starts counting instructions
1299 at one. This also affects the instruction ranges reported by the
1300 'record function-call-history' command when given the /i modifier.
1302 * The command 'record function-call-history' supports a new modifier '/c' to
1303 indent the function names based on their call stack depth.
1304 The fields for the '/i' and '/l' modifier have been reordered.
1305 The source line range is now prefixed with 'at'.
1306 The instruction range is now prefixed with 'inst'.
1307 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1308 "record instruction-history" and "list" commands.
1310 * The ranges given as arguments to the 'record function-call-history' and
1311 'record instruction-history' commands are now inclusive.
1313 * The btrace record target now supports the 'record goto' command.
1314 For locations inside the execution trace, the back trace is computed
1315 based on the information stored in the execution trace.
1317 * The btrace record target supports limited reverse execution and replay.
1318 The target does not record data and therefore does not allow reading
1319 memory or registers.
1321 * The "catch syscall" command now works on s390*-linux* targets.
1323 * The "compare-sections" command is no longer specific to target
1324 remote. It now works with all targets.
1326 * All native targets are now consistently called "native".
1327 Consequently, the "target child", "target GNU", "target djgpp",
1328 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1329 commands have been replaced with "target native". The QNX/NTO port
1330 leaves the "procfs" target in place and adds a "native" target for
1331 consistency with other ports. The impact on users should be minimal
1332 as these commands previously either throwed an error, or were
1333 no-ops. The target's name is visible in the output of the following
1334 commands: "help target", "info target", "info files", "maint print
1337 * The "target native" command now connects to the native target. This
1338 can be used to launch native programs even when "set
1339 auto-connect-native-target" is set to off.
1341 * GDB now supports access to Intel MPX registers on GNU/Linux.
1343 * Support for Intel AVX-512 registers on GNU/Linux.
1344 Support displaying and modifying Intel AVX-512 registers
1345 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1347 * New remote packets
1349 qXfer:btrace:read's annex
1350 The qXfer:btrace:read packet supports a new annex 'delta' to read
1351 branch trace incrementally.
1355 ** Valid Python operations on gdb.Value objects representing
1356 structs/classes invoke the corresponding overloaded operators if
1358 ** New `Xmethods' feature in the Python API. Xmethods are
1359 additional methods or replacements for existing methods of a C++
1360 class. This feature is useful for those cases where a method
1361 defined in C++ source code could be inlined or optimized out by
1362 the compiler, making it unavailable to GDB.
1365 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1367 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1368 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1369 its alias "share", instead.
1371 * The commands "set remotebaud" and "show remotebaud" are no longer
1372 supported. Use "set serial baud" and "show serial baud" (respectively)
1377 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1378 target-async". The latter is left as a deprecated alias of the
1379 former for backward compatibility. If the target supports it,
1380 CLI background execution commands are now always possible by
1381 default, independently of whether the frontend stated a
1382 preference for asynchronous execution with "-gdb-set mi-async".
1383 Previously "-gdb-set target-async off" affected both MI execution
1384 commands and CLI execution commands.
1386 *** Changes in GDB 7.7
1388 * Improved support for process record-replay and reverse debugging on
1389 arm*-linux* targets. Support for thumb32 and syscall instruction
1390 recording has been added.
1392 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1394 * GDB now supports Fission DWP file format version 2.
1395 http://gcc.gnu.org/wiki/DebugFission
1397 * New convenience function "$_isvoid", to check whether an expression
1398 is void. A void expression is an expression where the type of the
1399 result is "void". For example, some convenience variables may be
1400 "void" when evaluated (e.g., "$_exitcode" before the execution of
1401 the program being debugged; or an undefined convenience variable).
1402 Another example, when calling a function whose return type is
1405 * The "maintenance print objfiles" command now takes an optional regexp.
1407 * The "catch syscall" command now works on arm*-linux* targets.
1409 * GDB now consistently shows "<not saved>" when printing values of
1410 registers the debug info indicates have not been saved in the frame
1411 and there's nowhere to retrieve them from
1412 (callee-saved/call-clobbered registers):
1417 (gdb) info registers rax
1420 Before, the former would print "<optimized out>", and the latter
1421 "*value not available*".
1423 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1428 ** Frame filters and frame decorators have been added.
1429 ** Temporary breakpoints are now supported.
1430 ** Line tables representation has been added.
1431 ** New attribute 'parent_type' for gdb.Field objects.
1432 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1433 ** New attribute 'name' for gdb.Type objects.
1437 Nios II ELF nios2*-*-elf
1438 Nios II GNU/Linux nios2*-*-linux
1439 Texas Instruments MSP430 msp430*-*-elf
1441 * Removed native configurations
1443 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1444 been removed. ELF variants of these configurations are kept supported.
1446 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1447 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1448 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1449 i[34567]86-*-openbsd3.[0-3]
1450 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1451 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1452 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1456 Like "catch throw", but catches a re-thrown exception.
1457 maint check-psymtabs
1458 Renamed from old "maint check-symtabs".
1460 Perform consistency checks on symtabs.
1461 maint expand-symtabs
1462 Expand symtabs matching an optional regexp.
1465 Display the details of GDB configure-time options.
1467 maint set|show per-command
1468 maint set|show per-command space
1469 maint set|show per-command time
1470 maint set|show per-command symtab
1471 Enable display of per-command gdb resource usage.
1473 remove-symbol-file FILENAME
1474 remove-symbol-file -a ADDRESS
1475 Remove a symbol file added via add-symbol-file. The file to remove
1476 can be identified by its filename or by an address that lies within
1477 the boundaries of this symbol file in memory.
1480 info exceptions REGEXP
1481 Display the list of Ada exceptions defined in the program being
1482 debugged. If provided, only the exceptions whose names match REGEXP
1487 set debug symfile off|on
1489 Control display of debugging info regarding reading symbol files and
1490 symbol tables within those files
1492 set print raw frame-arguments
1493 show print raw frame-arguments
1494 Set/show whether to print frame arguments in raw mode,
1495 disregarding any defined pretty-printers.
1497 set remote trace-status-packet
1498 show remote trace-status-packet
1499 Set/show the use of remote protocol qTStatus packet.
1503 Control display of debugging messages related to Nios II targets.
1507 Control whether target-assisted range stepping is enabled.
1509 set startup-with-shell
1510 show startup-with-shell
1511 Specifies whether Unix child processes are started via a shell or
1516 Use the target memory cache for accesses to the code segment. This
1517 improves performance of remote debugging (particularly disassembly).
1519 * You can now use a literal value 'unlimited' for options that
1520 interpret 0 or -1 as meaning "unlimited". E.g., "set
1521 trace-buffer-size unlimited" is now an alias for "set
1522 trace-buffer-size -1" and "set height unlimited" is now an alias for
1525 * The "set debug symtab-create" debugging option of GDB has been changed to
1526 accept a verbosity level. 0 means "off", 1 provides basic debugging
1527 output, and values of 2 or greater provides more verbose output.
1529 * New command-line options
1531 Display the details of GDB configure-time options.
1533 * The command 'tsave' can now support new option '-ctf' to save trace
1534 buffer in Common Trace Format.
1536 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1539 * GDB now implements the the C++ 'typeid' operator.
1541 * The new convenience variable $_exception holds the exception being
1542 thrown or caught at an exception-related catchpoint.
1544 * The exception-related catchpoints, like "catch throw", now accept a
1545 regular expression which can be used to filter exceptions by type.
1547 * The new convenience variable $_exitsignal is automatically set to
1548 the terminating signal number when the program being debugged dies
1549 due to an uncaught signal.
1553 ** All MI commands now accept an optional "--language" option.
1554 Support for this feature can be verified by using the "-list-features"
1555 command, which should contain "language-option".
1557 ** The new command -info-gdb-mi-command allows the user to determine
1558 whether a GDB/MI command is supported or not.
1560 ** The "^error" result record returned when trying to execute an undefined
1561 GDB/MI command now provides a variable named "code" whose content is the
1562 "undefined-command" error code. Support for this feature can be verified
1563 by using the "-list-features" command, which should contain
1564 "undefined-command-error-code".
1566 ** The -trace-save MI command can optionally save trace buffer in Common
1569 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1571 ** The command -data-list-register-values now accepts an optional
1572 "--skip-unavailable" option. When used, only the available registers
1575 ** The new command -trace-frame-collected dumps collected variables,
1576 computed expressions, tvars, memory and registers in a traceframe.
1578 ** The commands -stack-list-locals, -stack-list-arguments and
1579 -stack-list-variables now accept an option "--skip-unavailable".
1580 When used, only the available locals or arguments are displayed.
1582 ** The -exec-run command now accepts an optional "--start" option.
1583 When used, the command follows the same semantics as the "start"
1584 command, stopping the program's execution at the start of its
1585 main subprogram. Support for this feature can be verified using
1586 the "-list-features" command, which should contain
1587 "exec-run-start-option".
1589 ** The new commands -catch-assert and -catch-exceptions insert
1590 catchpoints stopping the program when Ada exceptions are raised.
1592 ** The new command -info-ada-exceptions provides the equivalent of
1593 the new "info exceptions" command.
1595 * New system-wide configuration scripts
1596 A GDB installation now provides scripts suitable for use as system-wide
1597 configuration scripts for the following systems:
1601 * GDB now supports target-assigned range stepping with remote targets.
1602 This improves the performance of stepping source lines by reducing
1603 the number of control packets from/to GDB. See "New remote packets"
1606 * GDB now understands the element 'tvar' in the XML traceframe info.
1607 It has the id of the collected trace state variables.
1609 * On S/390 targets that provide the transactional-execution feature,
1610 the program interruption transaction diagnostic block (TDB) is now
1611 represented as a number of additional "registers" in GDB.
1613 * New remote packets
1617 The vCont packet supports a new 'r' action, that tells the remote
1618 stub to step through an address range itself, without GDB
1619 involvemement at each single-step.
1621 qXfer:libraries-svr4:read's annex
1622 The previously unused annex of the qXfer:libraries-svr4:read packet
1623 is now used to support passing an argument list. The remote stub
1624 reports support for this argument list to GDB's qSupported query.
1625 The defined arguments are "start" and "prev", used to reduce work
1626 necessary for library list updating, resulting in significant
1629 * New features in the GDB remote stub, GDBserver
1631 ** GDBserver now supports target-assisted range stepping. Currently
1632 enabled on x86/x86_64 GNU/Linux targets.
1634 ** GDBserver now adds element 'tvar' in the XML in the reply to
1635 'qXfer:traceframe-info:read'. It has the id of the collected
1636 trace state variables.
1638 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1641 * New 'z' formatter for printing and examining memory, this displays the
1642 value as hexadecimal zero padded on the left to the size of the type.
1644 * GDB can now use Windows x64 unwinding data.
1646 * The "set remotebaud" command has been replaced by "set serial baud".
1647 Similarly, "show remotebaud" has been replaced by "show serial baud".
1648 The "set remotebaud" and "show remotebaud" commands are still available
1649 to provide backward compatibility with older versions of GDB.
1651 *** Changes in GDB 7.6
1653 * Target record has been renamed to record-full.
1654 Record/replay is now enabled with the "record full" command.
1655 This also affects settings that are associated with full record/replay
1656 that have been moved from "set/show record" to "set/show record full":
1658 set|show record full insn-number-max
1659 set|show record full stop-at-limit
1660 set|show record full memory-query
1662 * A new record target "record-btrace" has been added. The new target
1663 uses hardware support to record the control-flow of a process. It
1664 does not support replaying the execution, but it implements the
1665 below new commands for investigating the recorded execution log.
1666 This new recording method can be enabled using:
1670 The "record-btrace" target is only available on Intel Atom processors
1671 and requires a Linux kernel 2.6.32 or later.
1673 * Two new commands have been added for record/replay to give information
1674 about the recorded execution without having to replay the execution.
1675 The commands are only supported by "record btrace".
1677 record instruction-history prints the execution history at
1678 instruction granularity
1680 record function-call-history prints the execution history at
1681 function granularity
1683 * New native configurations
1685 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1686 FreeBSD/powerpc powerpc*-*-freebsd
1687 x86_64/Cygwin x86_64-*-cygwin*
1688 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1692 ARM AArch64 aarch64*-*-elf
1693 ARM AArch64 GNU/Linux aarch64*-*-linux
1694 Lynx 178 PowerPC powerpc-*-lynx*178
1695 x86_64/Cygwin x86_64-*-cygwin*
1696 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1698 * If the configured location of system.gdbinit file (as given by the
1699 --with-system-gdbinit option at configure time) is in the
1700 data-directory (as specified by --with-gdb-datadir at configure
1701 time) or in one of its subdirectories, then GDB will look for the
1702 system-wide init file in the directory specified by the
1703 --data-directory command-line option.
1705 * New command line options:
1707 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1708 other initialization files, unlike -nx which disables all of them.
1710 * Removed command line options
1712 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1715 * The 'ptype' and 'whatis' commands now accept an argument to control
1718 * 'info proc' now works on some core files.
1722 ** Vectors can be created with gdb.Type.vector.
1724 ** Python's atexit.register now works in GDB.
1726 ** Types can be pretty-printed via a Python API.
1728 ** Python 3 is now supported (in addition to Python 2.4 or later)
1730 ** New class gdb.Architecture exposes GDB's internal representation
1731 of architecture in the Python API.
1733 ** New method Frame.architecture returns the gdb.Architecture object
1734 corresponding to the frame's architecture.
1736 * New Python-based convenience functions:
1738 ** $_memeq(buf1, buf2, length)
1739 ** $_streq(str1, str2)
1741 ** $_regex(str, regex)
1743 * The 'cd' command now defaults to using '~' (the home directory) if not
1746 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1747 default for GCC since November 2000.
1749 * The command 'forward-search' can now be abbreviated as 'fo'.
1751 * The command 'info tracepoints' can now display 'installed on target'
1752 or 'not installed on target' for each non-pending location of tracepoint.
1754 * New configure options
1756 --enable-libmcheck/--disable-libmcheck
1757 By default, development versions are built with -lmcheck on hosts
1758 that support it, in order to help track memory corruption issues.
1759 Release versions, on the other hand, are built without -lmcheck
1760 by default. The --enable-libmcheck/--disable-libmcheck configure
1761 options allow the user to override that default.
1762 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1763 This configure option allows the user to build GDB with
1764 libbabeltrace using which GDB can read Common Trace Format data.
1766 * New commands (for set/show, see "New options" below)
1769 Catch signals. This is similar to "handle", but allows commands and
1770 conditions to be attached.
1773 List the BFDs known to GDB.
1775 python-interactive [command]
1777 Start a Python interactive prompt, or evaluate the optional command
1778 and print the result of expressions.
1781 "py" is a new alias for "python".
1783 enable type-printer [name]...
1784 disable type-printer [name]...
1785 Enable or disable type printers.
1789 ** For the Renesas Super-H architecture, the "regs" command has been removed
1790 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1795 set print type methods (on|off)
1796 show print type methods
1797 Control whether method declarations are displayed by "ptype".
1798 The default is to show them.
1800 set print type typedefs (on|off)
1801 show print type typedefs
1802 Control whether typedef definitions are displayed by "ptype".
1803 The default is to show them.
1805 set filename-display basename|relative|absolute
1806 show filename-display
1807 Control the way in which filenames is displayed.
1808 The default is "relative", which preserves previous behavior.
1810 set trace-buffer-size
1811 show trace-buffer-size
1812 Request target to change the size of trace buffer.
1814 set remote trace-buffer-size-packet auto|on|off
1815 show remote trace-buffer-size-packet
1816 Control the use of the remote protocol `QTBuffer:size' packet.
1820 Control display of debugging messages related to ARM AArch64.
1823 set debug coff-pe-read
1824 show debug coff-pe-read
1825 Control display of debugging messages related to reading of COFF/PE
1830 Control display of debugging messages related to Mach-O symbols
1833 set debug notification
1834 show debug notification
1835 Control display of debugging info for async remote notification.
1839 ** Command parameter changes are now notified using new async record
1840 "=cmd-param-changed".
1841 ** Trace frame changes caused by command "tfind" are now notified using
1842 new async record "=traceframe-changed".
1843 ** The creation, deletion and modification of trace state variables
1844 are now notified using new async records "=tsv-created",
1845 "=tsv-deleted" and "=tsv-modified".
1846 ** The start and stop of process record are now notified using new
1847 async record "=record-started" and "=record-stopped".
1848 ** Memory changes are now notified using new async record
1850 ** The data-disassemble command response will include a "fullname" field
1851 containing the absolute file name when source has been requested.
1852 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1853 command, to allow pattern filling of memory areas.
1854 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1855 library load/unload events.
1856 ** The response to breakpoint commands and breakpoint async records
1857 includes an "installed" field containing a boolean state about each
1858 non-pending tracepoint location is whether installed on target or not.
1859 ** Output of the "-trace-status" command includes a "trace-file" field
1860 containing the name of the trace file being examined. This field is
1861 optional, and only present when examining a trace file.
1862 ** The "fullname" field is now always present along with the "file" field,
1863 even if the file cannot be found by GDB.
1865 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1866 You must have the LZMA library available when configuring GDB for this
1867 feature to be enabled. For more information, see:
1868 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1870 * New remote packets
1873 Set the size of trace buffer. The remote stub reports support for this
1874 packet to gdb's qSupported query.
1877 Enable Branch Trace Store (BTS)-based branch tracing for the current
1878 thread. The remote stub reports support for this packet to gdb's
1882 Disable branch tracing for the current thread. The remote stub reports
1883 support for this packet to gdb's qSupported query.
1886 Read the traced branches for the current thread. The remote stub
1887 reports support for this packet to gdb's qSupported query.
1889 *** Changes in GDB 7.5
1891 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1892 for more x32 ABI info.
1894 * GDB now supports access to MIPS DSP registers on Linux targets.
1896 * GDB now supports debugging microMIPS binaries.
1898 * The "info os" command on GNU/Linux can now display information on
1899 several new classes of objects managed by the operating system:
1900 "info os procgroups" lists process groups
1901 "info os files" lists file descriptors
1902 "info os sockets" lists internet-domain sockets
1903 "info os shm" lists shared-memory regions
1904 "info os semaphores" lists semaphores
1905 "info os msg" lists message queues
1906 "info os modules" lists loaded kernel modules
1908 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1909 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1910 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1911 options and inspect the probe arguments using the new $_probe_arg family
1912 of convenience variables. You can obtain more information about SystemTap
1913 in <http://sourceware.org/systemtap/>.
1915 * GDB now supports reversible debugging on ARM, it allows you to
1916 debug basic ARM and THUMB instructions, and provides
1917 record/replay support.
1919 * The option "symbol-reloading" has been deleted as it is no longer used.
1923 ** GDB commands implemented in Python can now be put in command class
1926 ** The "maint set python print-stack on|off" is now deleted.
1928 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1929 apply "flag enum"-style pretty-printing to any enum.
1931 ** gdb.lookup_symbol can now work when there is no current frame.
1933 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1934 the source at which the symbol was defined.
1936 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1937 method 'value'. The former indicates whether the symbol needs a
1938 frame in order to compute its value, and the latter computes the
1941 ** A new method 'referenced_value' on gdb.Value objects which can
1942 dereference pointer as well as C++ reference values.
1944 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1945 which return the global and static blocks (as gdb.Block objects),
1946 of the underlying symbol table, respectively.
1948 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1949 object associated with a PC value.
1951 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1952 of the address range occupied by code for the current source line.
1954 * Go language support.
1955 GDB now supports debugging programs written in the Go programming
1958 * GDBserver now supports stdio connections.
1959 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1961 * The binary "gdbtui" can no longer be built or installed.
1962 Use "gdb -tui" instead.
1964 * GDB will now print "flag" enums specially. A flag enum is one where
1965 all the enumerator values have no bits in common when pairwise
1966 "and"ed. When printing a value whose type is a flag enum, GDB will
1967 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1968 (gdb) print (enum E) 3
1971 * The filename part of a linespec will now match trailing components
1972 of a source file name. For example, "break gcc/expr.c:1000" will
1973 now set a breakpoint in build/gcc/expr.c, but not
1974 build/libcpp/expr.c.
1976 * The "info proc" and "generate-core-file" commands will now also
1977 work on remote targets connected to GDBserver on Linux.
1979 * The command "info catch" has been removed. It has been disabled
1980 since December 2007.
1982 * The "catch exception" and "catch assert" commands now accept
1983 a condition at the end of the command, much like the "break"
1984 command does. For instance:
1986 (gdb) catch exception Constraint_Error if Barrier = True
1988 Previously, it was possible to add a condition to such catchpoints,
1989 but it had to be done as a second step, after the catchpoint had been
1990 created, using the "condition" command.
1992 * The "info static-tracepoint-marker" command will now also work on
1993 native Linux targets with in-process agent.
1995 * GDB can now set breakpoints on inlined functions.
1997 * The .gdb_index section has been updated to include symbols for
1998 inlined functions. GDB will ignore older .gdb_index sections by
1999 default, which could cause symbol files to be loaded more slowly
2000 until their .gdb_index sections can be recreated. The new command
2001 "set use-deprecated-index-sections on" will cause GDB to use any older
2002 .gdb_index sections it finds. This will restore performance, but the
2003 ability to set breakpoints on inlined functions will be lost in symbol
2004 files with older .gdb_index sections.
2006 The .gdb_index section has also been updated to record more information
2007 about each symbol. This speeds up the "info variables", "info functions"
2008 and "info types" commands when used with programs having the .gdb_index
2009 section, as well as speeding up debugging with shared libraries using
2010 the .gdb_index section.
2012 * Ada support for GDB/MI Variable Objects has been added.
2014 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2019 ** New command -info-os is the MI equivalent of "info os".
2021 ** Output logs ("set logging" and related) now include MI output.
2025 ** "set use-deprecated-index-sections on|off"
2026 "show use-deprecated-index-sections on|off"
2027 Controls the use of deprecated .gdb_index sections.
2029 ** "catch load" and "catch unload" can be used to stop when a shared
2030 library is loaded or unloaded, respectively.
2032 ** "enable count" can be used to auto-disable a breakpoint after
2035 ** "info vtbl" can be used to show the virtual method tables for
2036 C++ and Java objects.
2038 ** "explore" and its sub commands "explore value" and "explore type"
2039 can be used to recursively explore values and types of
2040 expressions. These commands are available only if GDB is
2041 configured with '--with-python'.
2043 ** "info auto-load" shows status of all kinds of auto-loaded files,
2044 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2045 sequences of commands files, "info auto-load python-scripts"
2046 shows status of auto-loading Python script files,
2047 "info auto-load local-gdbinit" shows status of loading init file
2048 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2049 status of inferior specific thread debugging shared library loading.
2051 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2052 and "show auto-load-scripts" commands have been deprecated, use their
2053 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2054 and "show auto-load python-scripts" counterparts instead.
2056 ** "dprintf location,format,args..." creates a dynamic printf, which
2057 is basically a breakpoint that does a printf and immediately
2058 resumes your program's execution, so it is like a printf that you
2059 can insert dynamically at runtime instead of at compiletime.
2061 ** "set print symbol"
2063 Controls whether GDB attempts to display the symbol, if any,
2064 corresponding to addresses it prints. This defaults to "on", but
2065 you can set it to "off" to restore GDB's previous behavior.
2067 * Deprecated commands
2069 ** For the Renesas Super-H architecture, the "regs" command has been
2070 deprecated, and "info all-registers" should be used instead.
2074 Renesas RL78 rl78-*-elf
2075 HP OpenVMS ia64 ia64-hp-openvms*
2077 * GDBserver supports evaluation of breakpoint conditions. When
2078 support is advertised by GDBserver, GDB may be told to send the
2079 breakpoint conditions in bytecode form to GDBserver. GDBserver
2080 will only report the breakpoint trigger to GDB when its condition
2085 set mips compression
2086 show mips compression
2087 Select the compressed ISA encoding used in functions that have no symbol
2088 information available. The encoding can be set to either of:
2091 and is updated automatically from ELF file flags if available.
2093 set breakpoint condition-evaluation
2094 show breakpoint condition-evaluation
2095 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2096 GDBserver ("target"). Default option "auto" chooses the most efficient
2098 This option can improve debugger efficiency depending on the speed of the
2102 Disable auto-loading globally.
2105 Show auto-loading setting of all kinds of auto-loaded files.
2107 set auto-load gdb-scripts on|off
2108 show auto-load gdb-scripts
2109 Control auto-loading of GDB canned sequences of commands files.
2111 set auto-load python-scripts on|off
2112 show auto-load python-scripts
2113 Control auto-loading of Python script files.
2115 set auto-load local-gdbinit on|off
2116 show auto-load local-gdbinit
2117 Control loading of init file (.gdbinit) from current directory.
2119 set auto-load libthread-db on|off
2120 show auto-load libthread-db
2121 Control auto-loading of inferior specific thread debugging shared library.
2123 set auto-load scripts-directory <dir1>[:<dir2>...]
2124 show auto-load scripts-directory
2125 Set a list of directories from which to load auto-loaded scripts.
2126 Automatically loaded Python scripts and GDB scripts are located in one
2127 of the directories listed by this option.
2128 The delimiter (':' above) may differ according to the host platform.
2130 set auto-load safe-path <dir1>[:<dir2>...]
2131 show auto-load safe-path
2132 Set a list of directories from which it is safe to auto-load files.
2133 The delimiter (':' above) may differ according to the host platform.
2135 set debug auto-load on|off
2136 show debug auto-load
2137 Control display of debugging info for auto-loading the files above.
2139 set dprintf-style gdb|call|agent
2141 Control the way in which a dynamic printf is performed; "gdb"
2142 requests a GDB printf command, while "call" causes dprintf to call a
2143 function in the inferior. "agent" requests that the target agent
2144 (such as GDBserver) do the printing.
2146 set dprintf-function <expr>
2147 show dprintf-function
2148 set dprintf-channel <expr>
2149 show dprintf-channel
2150 Set the function and optional first argument to the call when using
2151 the "call" style of dynamic printf.
2153 set disconnected-dprintf on|off
2154 show disconnected-dprintf
2155 Control whether agent-style dynamic printfs continue to be in effect
2156 after GDB disconnects.
2158 * New configure options
2160 --with-auto-load-dir
2161 Configure default value for the 'set auto-load scripts-directory'
2162 setting above. It defaults to '$debugdir:$datadir/auto-load',
2163 $debugdir representing global debugging info directories (available
2164 via 'show debug-file-directory') and $datadir representing GDB's data
2165 directory (available via 'show data-directory').
2167 --with-auto-load-safe-path
2168 Configure default value for the 'set auto-load safe-path' setting
2169 above. It defaults to the --with-auto-load-dir setting.
2171 --without-auto-load-safe-path
2172 Set 'set auto-load safe-path' to '/', effectively disabling this
2175 * New remote packets
2177 z0/z1 conditional breakpoints extension
2179 The z0/z1 breakpoint insertion packets have been extended to carry
2180 a list of conditional expressions over to the remote stub depending on the
2181 condition evaluation mode. The use of this extension can be controlled
2182 via the "set remote conditional-breakpoints-packet" command.
2186 Specify the signals which the remote stub may pass to the debugged
2187 program without GDB involvement.
2189 * New command line options
2191 --init-command=FILE, -ix Like --command, -x but execute it
2192 before loading inferior.
2193 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2194 execute it before loading inferior.
2196 *** Changes in GDB 7.4
2198 * GDB now handles ambiguous linespecs more consistently; the existing
2199 FILE:LINE support has been expanded to other types of linespecs. A
2200 breakpoint will now be set on all matching locations in all
2201 inferiors, and locations will be added or removed according to
2204 * GDB now allows you to skip uninteresting functions and files when
2205 stepping with the "skip function" and "skip file" commands.
2207 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2208 and "show remote hardware-watchpoint-length-limit". These allows to
2209 set or show the maximum length limit (in bytes) of a remote
2210 target hardware watchpoint.
2212 This allows e.g. to use "unlimited" hardware watchpoints with the
2213 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2214 watchpoints are slower than real hardware watchpoints but are
2215 significantly faster than gdb software watchpoints.
2219 ** The register_pretty_printer function in module gdb.printing now takes
2220 an optional `replace' argument. If True, the new printer replaces any
2223 ** The "maint set python print-stack on|off" command has been
2224 deprecated and will be deleted in GDB 7.5.
2225 A new command: "set python print-stack none|full|message" has
2226 replaced it. Additionally, the default for "print-stack" is
2227 now "message", which just prints the error message without
2230 ** A prompt substitution hook (prompt_hook) is now available to the
2233 ** A new Python module, gdb.prompt has been added to the GDB Python
2234 modules library. This module provides functionality for
2235 escape sequences in prompts (used by set/show
2236 extended-prompt). These escape sequences are replaced by their
2237 corresponding value.
2239 ** Python commands and convenience-functions located in
2240 'data-directory'/python/gdb/command and
2241 'data-directory'/python/gdb/function are now automatically loaded
2244 ** Blocks now provide four new attributes. global_block and
2245 static_block will return the global and static blocks
2246 respectively. is_static and is_global are boolean attributes
2247 that indicate if the block is one of those two types.
2249 ** Symbols now provide the "type" attribute, the type of the symbol.
2251 ** The "gdb.breakpoint" function has been deprecated in favor of
2254 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2255 of a function. This class is based on the "finish" command
2256 available in the CLI.
2258 ** Type objects for struct and union types now allow access to
2259 the fields using standard Python dictionary (mapping) methods.
2260 For example, "some_type['myfield']" now works, as does
2261 "some_type.items()".
2263 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2266 ** A new function, "deep_items" has been added to the gdb.types
2267 module in the GDB Python modules library. This function returns
2268 an iterator over the fields of a struct or union type. Unlike
2269 the standard Python "iteritems" method, it will recursively traverse
2270 any anonymous fields.
2274 ** "*stopped" events can report several new "reason"s, such as
2277 ** Breakpoint changes are now notified using new async records, like
2278 "=breakpoint-modified".
2280 ** New command -ada-task-info.
2282 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2283 $sdir specifies the default system locations of shared libraries.
2284 $pdir specifies the directory where the libpthread used by the application
2287 GDB no longer looks in $sdir and $pdir after it has searched the directories
2288 mentioned in libthread-db-search-path. If you want to search those
2289 directories, they must be specified in libthread-db-search-path.
2290 The default value of libthread-db-search-path on GNU/Linux and Solaris
2291 systems is now "$sdir:$pdir".
2293 $pdir is not supported by gdbserver, it is currently ignored.
2294 $sdir is supported by gdbserver.
2296 * New configure option --with-iconv-bin.
2297 When using the internationalization support like the one in the GNU C
2298 library, GDB will invoke the "iconv" program to get a list of supported
2299 character sets. If this program lives in a non-standard location, one can
2300 use this option to specify where to find it.
2302 * When natively debugging programs on PowerPC BookE processors running
2303 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2304 watchpoints, which specify a mask in addition to an address to watch.
2305 The mask specifies that some bits of an address (the bits which are
2306 reset in the mask) should be ignored when matching the address accessed
2307 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2308 section in the user manual for more details.
2310 * The new option --once causes GDBserver to stop listening for connections once
2311 the first connection is made. The listening port used by GDBserver will
2312 become available after that.
2314 * New commands "info macros" and "alias" have been added.
2316 * New function parameters suffix @entry specifies value of function parameter
2317 at the time the function got called. Entry values are available only since
2323 "!" is now an alias of the "shell" command.
2324 Note that no space is needed between "!" and SHELL COMMAND.
2328 watch EXPRESSION mask MASK_VALUE
2329 The watch command now supports the mask argument which allows creation
2330 of masked watchpoints, if the current architecture supports this feature.
2332 info auto-load-scripts [REGEXP]
2333 This command was formerly named "maintenance print section-scripts".
2334 It is now generally useful and is no longer a maintenance-only command.
2336 info macro [-all] [--] MACRO
2337 The info macro command has new options `-all' and `--'. The first for
2338 printing all definitions of a macro. The second for explicitly specifying
2339 the end of arguments and the beginning of the macro name in case the macro
2340 name starts with a hyphen.
2342 collect[/s] EXPRESSIONS
2343 The tracepoint collect command now takes an optional modifier "/s"
2344 that directs it to dereference pointer-to-character types and
2345 collect the bytes of memory up to a zero byte. The behavior is
2346 similar to what you see when you use the regular print command on a
2347 string. An optional integer following the "/s" sets a bound on the
2348 number of bytes that will be collected.
2351 The trace start command now interprets any supplied arguments as a
2352 note to be recorded with the trace run, with an effect similar to
2353 setting the variable trace-notes.
2356 The trace stop command now interprets any arguments as a note to be
2357 mentioned along with the tstatus report that the trace was stopped
2358 with a command. The effect is similar to setting the variable
2361 * Tracepoints can now be enabled and disabled at any time after a trace
2362 experiment has been started using the standard "enable" and "disable"
2363 commands. It is now possible to start a trace experiment with no enabled
2364 tracepoints; GDB will display a warning, but will allow the experiment to
2365 begin, assuming that tracepoints will be enabled as needed while the trace
2368 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2369 locations with 4-byte instructions, when they were previously
2370 limited to locations with instructions of 5 bytes or longer.
2374 set debug dwarf2-read
2375 show debug dwarf2-read
2376 Turns on or off display of debugging messages related to reading
2377 DWARF debug info. The default is off.
2379 set debug symtab-create
2380 show debug symtab-create
2381 Turns on or off display of debugging messages related to symbol table
2382 creation. The default is off.
2385 show extended-prompt
2386 Set the GDB prompt, and allow escape sequences to be inserted to
2387 display miscellaneous information (see 'help set extended-prompt'
2388 for the list of sequences). This prompt (and any information
2389 accessed through the escape sequences) is updated every time the
2390 prompt is displayed.
2392 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2393 show print entry-values
2394 Set printing of frame argument values at function entry. In some cases
2395 GDB can determine the value of function argument which was passed by the
2396 function caller, even if the value was modified inside the called function.
2398 set debug entry-values
2399 show debug entry-values
2400 Control display of debugging info for determining frame argument values at
2401 function entry and virtual tail call frames.
2403 set basenames-may-differ
2404 show basenames-may-differ
2405 Set whether a source file may have multiple base names.
2406 (A "base name" is the name of a file with the directory part removed.
2407 Example: The base name of "/home/user/hello.c" is "hello.c".)
2408 If set, GDB will canonicalize file names (e.g., expand symlinks)
2409 before comparing them. Canonicalization is an expensive operation,
2410 but it allows the same file be known by more than one base name.
2411 If not set (the default), all source files are assumed to have just
2412 one base name, and gdb will do file name comparisons more efficiently.
2418 Set a user name and notes for the current and any future trace runs.
2419 This is useful for long-running and/or disconnected traces, to
2420 inform others (or yourself) as to who is running the trace, supply
2421 contact information, or otherwise explain what is going on.
2423 set trace-stop-notes
2424 show trace-stop-notes
2425 Set a note attached to the trace run, that is displayed when the
2426 trace has been stopped by a tstop command. This is useful for
2427 instance as an explanation, if you are stopping a trace run that was
2428 started by someone else.
2430 * New remote packets
2434 Dynamically enable a tracepoint in a started trace experiment.
2438 Dynamically disable a tracepoint in a started trace experiment.
2442 Set the user and notes of the trace run.
2446 Query the current status of a tracepoint.
2450 Query the minimum length of instruction at which a fast tracepoint may
2453 * Dcache size (number of lines) and line-size are now runtime-configurable
2454 via "set dcache line" and "set dcache line-size" commands.
2458 Texas Instruments TMS320C6x tic6x-*-*
2462 Renesas RL78 rl78-*-elf
2464 *** Changes in GDB 7.3.1
2466 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2468 *** Changes in GDB 7.3
2470 * GDB has a new command: "thread find [REGEXP]".
2471 It finds the thread id whose name, target id, or thread extra info
2472 matches the given regular expression.
2474 * The "catch syscall" command now works on mips*-linux* targets.
2476 * The -data-disassemble MI command now supports modes 2 and 3 for
2477 dumping the instruction opcodes.
2479 * New command line options
2481 -data-directory DIR Specify DIR as the "data-directory".
2482 This is mostly for testing purposes.
2484 * The "maint set python auto-load on|off" command has been renamed to
2485 "set auto-load-scripts on|off".
2487 * GDB has a new command: "set directories".
2488 It is like the "dir" command except that it replaces the
2489 source path list instead of augmenting it.
2491 * GDB now understands thread names.
2493 On GNU/Linux, "info threads" will display the thread name as set by
2494 prctl or pthread_setname_np.
2496 There is also a new command, "thread name", which can be used to
2497 assign a name internally for GDB to display.
2500 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2501 has been integrated into GDB.
2505 ** The function gdb.Write now accepts an optional keyword 'stream'.
2506 This keyword, when provided, will direct the output to either
2507 stdout, stderr, or GDB's logging output.
2509 ** Parameters can now be be sub-classed in Python, and in particular
2510 you may implement the get_set_doc and get_show_doc functions.
2511 This improves how Parameter set/show documentation is processed
2512 and allows for more dynamic content.
2514 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2515 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2516 have an is_valid method.
2518 ** Breakpoints can now be sub-classed in Python, and in particular
2519 you may implement a 'stop' function that is executed each time
2520 the inferior reaches that breakpoint.
2522 ** New function gdb.lookup_global_symbol looks up a global symbol.
2524 ** GDB values in Python are now callable if the value represents a
2525 function. For example, if 'some_value' represents a function that
2526 takes two integer parameters and returns a value, you can call
2527 that function like so:
2529 result = some_value (10,20)
2531 ** Module gdb.types has been added.
2532 It contains a collection of utilities for working with gdb.Types objects:
2533 get_basic_type, has_field, make_enum_dict.
2535 ** Module gdb.printing has been added.
2536 It contains utilities for writing and registering pretty-printers.
2537 New classes: PrettyPrinter, SubPrettyPrinter,
2538 RegexpCollectionPrettyPrinter.
2539 New function: register_pretty_printer.
2541 ** New commands "info pretty-printers", "enable pretty-printer" and
2542 "disable pretty-printer" have been added.
2544 ** gdb.parameter("directories") is now available.
2546 ** New function gdb.newest_frame returns the newest frame in the
2549 ** The gdb.InferiorThread class has a new "name" attribute. This
2550 holds the thread's name.
2552 ** Python Support for Inferior events.
2553 Python scripts can add observers to be notified of events
2554 occurring in the process being debugged.
2555 The following events are currently supported:
2556 - gdb.events.cont Continue event.
2557 - gdb.events.exited Inferior exited event.
2558 - gdb.events.stop Signal received, and Breakpoint hit events.
2562 ** GDB now puts template parameters in scope when debugging in an
2563 instantiation. For example, if you have:
2565 template<int X> int func (void) { return X; }
2567 then if you step into func<5>, "print X" will show "5". This
2568 feature requires proper debuginfo support from the compiler; it
2569 was added to GCC 4.5.
2571 ** The motion commands "next", "finish", "until", and "advance" now
2572 work better when exceptions are thrown. In particular, GDB will
2573 no longer lose control of the inferior; instead, the GDB will
2574 stop the inferior at the point at which the exception is caught.
2575 This functionality requires a change in the exception handling
2576 code that was introduced in GCC 4.5.
2578 * GDB now follows GCC's rules on accessing volatile objects when
2579 reading or writing target state during expression evaluation.
2580 One notable difference to prior behavior is that "print x = 0"
2581 no longer generates a read of x; the value of the assignment is
2582 now always taken directly from the value being assigned.
2584 * GDB now has some support for using labels in the program's source in
2585 linespecs. For instance, you can use "advance label" to continue
2586 execution to a label.
2588 * GDB now has support for reading and writing a new .gdb_index
2589 section. This section holds a fast index of DWARF debugging
2590 information and can be used to greatly speed up GDB startup and
2591 operation. See the documentation for `save gdb-index' for details.
2593 * The "watch" command now accepts an optional "-location" argument.
2594 When used, this causes GDB to watch the memory referred to by the
2595 expression. Such a watchpoint is never deleted due to it going out
2598 * GDB now supports thread debugging of core dumps on GNU/Linux.
2600 GDB now activates thread debugging using the libthread_db library
2601 when debugging GNU/Linux core dumps, similarly to when debugging
2602 live processes. As a result, when debugging a core dump file, GDB
2603 is now able to display pthread_t ids of threads. For example, "info
2604 threads" shows the same output as when debugging the process when it
2605 was live. In earlier releases, you'd see something like this:
2608 * 1 LWP 6780 main () at main.c:10
2610 While now you see this:
2613 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2615 It is also now possible to inspect TLS variables when debugging core
2618 When debugging a core dump generated on a machine other than the one
2619 used to run GDB, you may need to point GDB at the correct
2620 libthread_db library with the "set libthread-db-search-path"
2621 command. See the user manual for more details on this command.
2623 * When natively debugging programs on PowerPC BookE processors running
2624 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2625 which stop execution of the inferior whenever it executes an instruction
2626 at any address within the specified range. See the "PowerPC Embedded"
2627 section in the user manual for more details.
2629 * New features in the GDB remote stub, GDBserver
2631 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2632 and i686 LynxOS (version 5.x).
2634 ** GDBserver is now supported on Blackfin Linux.
2636 * New native configurations
2638 ia64 HP-UX ia64-*-hpux*
2642 Analog Devices, Inc. Blackfin Processor bfin-*
2644 * Ada task switching is now supported on sparc-elf targets when
2645 debugging a program using the Ravenscar Profile. For more information,
2646 see the "Tasking Support when using the Ravenscar Profile" section
2647 in the GDB user manual.
2649 * Guile support was removed.
2651 * New features in the GNU simulator
2653 ** The --map-info flag lists all known core mappings.
2655 ** CFI flashes may be simulated via the "cfi" device.
2657 *** Changes in GDB 7.2
2659 * Shared library support for remote targets by default
2661 When GDB is configured for a generic, non-OS specific target, like
2662 for example, --target=arm-eabi or one of the many *-*-elf targets,
2663 GDB now queries remote stubs for loaded shared libraries using the
2664 `qXfer:libraries:read' packet. Previously, shared library support
2665 was always disabled for such configurations.
2669 ** Argument Dependent Lookup (ADL)
2671 In C++ ADL lookup directs function search to the namespaces of its
2672 arguments even if the namespace has not been imported.
2682 Here the compiler will search for `foo' in the namespace of 'b'
2683 and find A::foo. GDB now supports this. This construct is commonly
2684 used in the Standard Template Library for operators.
2686 ** Improved User Defined Operator Support
2688 In addition to member operators, GDB now supports lookup of operators
2689 defined in a namespace and imported with a `using' directive, operators
2690 defined in the global scope, operators imported implicitly from an
2691 anonymous namespace, and the ADL operators mentioned in the previous
2693 GDB now also supports proper overload resolution for all the previously
2694 mentioned flavors of operators.
2696 ** static const class members
2698 Printing of static const class members that are initialized in the
2699 class definition has been fixed.
2701 * Windows Thread Information Block access.
2703 On Windows targets, GDB now supports displaying the Windows Thread
2704 Information Block (TIB) structure. This structure is visible either
2705 by using the new command `info w32 thread-information-block' or, by
2706 dereferencing the new convenience variable named `$_tlb', a
2707 thread-specific pointer to the TIB. This feature is also supported
2708 when remote debugging using GDBserver.
2710 * Static tracepoints
2712 Static tracepoints are calls in the user program into a tracing
2713 library. One such library is a port of the LTTng kernel tracer to
2714 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2715 When debugging with GDBserver, GDB now supports combining the GDB
2716 tracepoint machinery with such libraries. For example: the user can
2717 use GDB to probe a static tracepoint marker (a call from the user
2718 program into the tracing library) with the new "strace" command (see
2719 "New commands" below). This creates a "static tracepoint" in the
2720 breakpoint list, that can be manipulated with the same feature set
2721 as fast and regular tracepoints. E.g., collect registers, local and
2722 global variables, collect trace state variables, and define
2723 tracepoint conditions. In addition, the user can collect extra
2724 static tracepoint marker specific data, by collecting the new
2725 $_sdata internal variable. When analyzing the trace buffer, you can
2726 inspect $_sdata like any other variable available to GDB. For more
2727 information, see the "Tracepoints" chapter in GDB user manual. New
2728 remote packets have been defined to support static tracepoints, see
2729 the "New remote packets" section below.
2731 * Better reconstruction of tracepoints after disconnected tracing
2733 GDB will attempt to download the original source form of tracepoint
2734 definitions when starting a trace run, and then will upload these
2735 upon reconnection to the target, resulting in a more accurate
2736 reconstruction of the tracepoints that are in use on the target.
2740 You can now exercise direct control over the ways that GDB can
2741 affect your program. For instance, you can disallow the setting of
2742 breakpoints, so that the program can run continuously (assuming
2743 non-stop mode). In addition, the "observer" variable is available
2744 to switch all of the different controls; in observer mode, GDB
2745 cannot affect the target's behavior at all, which is useful for
2746 tasks like diagnosing live systems in the field.
2748 * The new convenience variable $_thread holds the number of the
2751 * New remote packets
2755 Return the address of the Windows Thread Information Block of a given thread.
2759 In response to several of the tracepoint packets, the target may now
2760 also respond with a number of intermediate `qRelocInsn' request
2761 packets before the final result packet, to have GDB handle
2762 relocating an instruction to execute at a different address. This
2763 is particularly useful for stubs that support fast tracepoints. GDB
2764 reports support for this feature in the qSupported packet.
2768 List static tracepoint markers in the target program.
2772 List static tracepoint markers at a given address in the target
2775 qXfer:statictrace:read
2777 Read the static trace data collected (by a `collect $_sdata'
2778 tracepoint action). The remote stub reports support for this packet
2779 to gdb's qSupported query.
2783 Send the current settings of GDB's permission flags.
2787 Send part of the source (textual) form of a tracepoint definition,
2788 which includes location, conditional, and action list.
2790 * The source command now accepts a -s option to force searching for the
2791 script in the source search path even if the script name specifies
2794 * New features in the GDB remote stub, GDBserver
2796 - GDBserver now support tracepoints (including fast tracepoints, and
2797 static tracepoints). The feature is currently supported by the
2798 i386-linux and amd64-linux builds. See the "Tracepoints support
2799 in gdbserver" section in the manual for more information.
2801 GDBserver JIT compiles the tracepoint's conditional agent
2802 expression bytecode into native code whenever possible for low
2803 overhead dynamic tracepoints conditionals. For such tracepoints,
2804 an expression that examines program state is evaluated when the
2805 tracepoint is reached, in order to determine whether to capture
2806 trace data. If the condition is simple and false, processing the
2807 tracepoint finishes very quickly and no data is gathered.
2809 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2810 for static tracepoints support.
2812 - GDBserver now supports x86_64 Windows 64-bit debugging.
2814 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2815 it understands register description.
2817 * The --batch flag now disables pagination and queries.
2819 * X86 general purpose registers
2821 GDB now supports reading/writing byte, word and double-word x86
2822 general purpose registers directly. This means you can use, say,
2823 $ah or $ax to refer, respectively, to the byte register AH and
2824 16-bit word register AX that are actually portions of the 32-bit
2825 register EAX or 64-bit register RAX.
2827 * The `commands' command now accepts a range of breakpoints to modify.
2828 A plain `commands' following a command that creates multiple
2829 breakpoints affects all the breakpoints set by that command. This
2830 applies to breakpoints set by `rbreak', and also applies when a
2831 single `break' command creates multiple breakpoints (e.g.,
2832 breakpoints on overloaded c++ functions).
2834 * The `rbreak' command now accepts a filename specification as part of
2835 its argument, limiting the functions selected by the regex to those
2836 in the specified file.
2838 * Support for remote debugging Windows and SymbianOS shared libraries
2839 from Unix hosts has been improved. Non Windows GDB builds now can
2840 understand target reported file names that follow MS-DOS based file
2841 system semantics, such as file names that include drive letters and
2842 use the backslash character as directory separator. This makes it
2843 possible to transparently use the "set sysroot" and "set
2844 solib-search-path" on Unix hosts to point as host copies of the
2845 target's shared libraries. See the new command "set
2846 target-file-system-kind" described below, and the "Commands to
2847 specify files" section in the user manual for more information.
2851 eval template, expressions...
2852 Convert the values of one or more expressions under the control
2853 of the string template to a command line, and call it.
2855 set target-file-system-kind unix|dos-based|auto
2856 show target-file-system-kind
2857 Set or show the assumed file system kind for target reported file
2860 save breakpoints <filename>
2861 Save all current breakpoint definitions to a file suitable for use
2862 in a later debugging session. To read the saved breakpoint
2863 definitions, use the `source' command.
2865 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2868 info static-tracepoint-markers
2869 Display information about static tracepoint markers in the target.
2871 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2872 Define a static tracepoint by probing a marker at the given
2873 function, line, address, or marker ID.
2877 Enable and disable observer mode.
2879 set may-write-registers on|off
2880 set may-write-memory on|off
2881 set may-insert-breakpoints on|off
2882 set may-insert-tracepoints on|off
2883 set may-insert-fast-tracepoints on|off
2884 set may-interrupt on|off
2885 Set individual permissions for GDB effects on the target. Note that
2886 some of these settings can have undesirable or surprising
2887 consequences, particularly when changed in the middle of a session.
2888 For instance, disabling the writing of memory can prevent
2889 breakpoints from being inserted, cause single-stepping to fail, or
2890 even crash your program, if you disable after breakpoints have been
2891 inserted. However, GDB should not crash.
2893 set record memory-query on|off
2894 show record memory-query
2895 Control whether to stop the inferior if memory changes caused
2896 by an instruction cannot be recorded.
2901 The disassemble command now supports "start,+length" form of two arguments.
2905 ** GDB now provides a new directory location, called the python directory,
2906 where Python scripts written for GDB can be installed. The location
2907 of that directory is <data-directory>/python, where <data-directory>
2908 is the GDB data directory. For more details, see section `Scripting
2909 GDB using Python' in the manual.
2911 ** The GDB Python API now has access to breakpoints, symbols, symbol
2912 tables, program spaces, inferiors, threads and frame's code blocks.
2913 Additionally, GDB Parameters can now be created from the API, and
2914 manipulated via set/show in the CLI.
2916 ** New functions gdb.target_charset, gdb.target_wide_charset,
2917 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2919 ** New exception gdb.GdbError.
2921 ** Pretty-printers are now also looked up in the current program space.
2923 ** Pretty-printers can now be individually enabled and disabled.
2925 ** GDB now looks for names of Python scripts to auto-load in a
2926 special section named `.debug_gdb_scripts', in addition to looking
2927 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2929 * Tracepoint actions were unified with breakpoint commands. In particular,
2930 there are no longer differences in "info break" output for breakpoints and
2931 tracepoints and the "commands" command can be used for both tracepoints and
2932 regular breakpoints.
2936 ARM Symbian arm*-*-symbianelf*
2938 * D language support.
2939 GDB now supports debugging programs written in the D programming
2942 * GDB now supports the extended ptrace interface for PowerPC which is
2943 available since Linux kernel version 2.6.34. This automatically enables
2944 any hardware breakpoints and additional hardware watchpoints available in
2945 the processor. The old ptrace interface exposes just one hardware
2946 watchpoint and no hardware breakpoints.
2948 * GDB is now able to use the Data Value Compare (DVC) register available on
2949 embedded PowerPC processors to implement in hardware simple watchpoint
2950 conditions of the form:
2952 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2954 This works in native GDB running on Linux kernels with the extended ptrace
2955 interface mentioned above.
2957 *** Changes in GDB 7.1
2961 ** Namespace Support
2963 GDB now supports importing of namespaces in C++. This enables the
2964 user to inspect variables from imported namespaces. Support for
2965 namepace aliasing has also been added. So, if a namespace is
2966 aliased in the current scope (e.g. namepace C=A; ) the user can
2967 print variables using the alias (e.g. (gdb) print C::x).
2971 All known bugs relating to the printing of virtual base class were
2972 fixed. It is now possible to call overloaded static methods using a
2977 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2978 and reinterpret_cast<> are now handled by the C++ expression parser.
2982 Xilinx MicroBlaze microblaze-*-*
2987 Xilinx MicroBlaze microblaze
2990 * Multi-program debugging.
2992 GDB now has support for multi-program (a.k.a. multi-executable or
2993 multi-exec) debugging. This allows for debugging multiple inferiors
2994 simultaneously each running a different program under the same GDB
2995 session. See "Debugging Multiple Inferiors and Programs" in the
2996 manual for more information. This implied some user visible changes
2997 in the multi-inferior support. For example, "info inferiors" now
2998 lists inferiors that are not running yet or that have exited
2999 already. See also "New commands" and "New options" below.
3001 * New tracing features
3003 GDB's tracepoint facility now includes several new features:
3005 ** Trace state variables
3007 GDB tracepoints now include support for trace state variables, which
3008 are variables managed by the target agent during a tracing
3009 experiment. They are useful for tracepoints that trigger each
3010 other, so for instance one tracepoint can count hits in a variable,
3011 and then a second tracepoint has a condition that is true when the
3012 count reaches a particular value. Trace state variables share the
3013 $-syntax of GDB convenience variables, and can appear in both
3014 tracepoint actions and condition expressions. Use the "tvariable"
3015 command to create, and "info tvariables" to view; see "Trace State
3016 Variables" in the manual for more detail.
3020 GDB now includes an option for defining fast tracepoints, which
3021 targets may implement more efficiently, such as by installing a jump
3022 into the target agent rather than a trap instruction. The resulting
3023 speedup can be by two orders of magnitude or more, although the
3024 tradeoff is that some program locations on some target architectures
3025 might not allow fast tracepoint installation, for instance if the
3026 instruction to be replaced is shorter than the jump. To request a
3027 fast tracepoint, use the "ftrace" command, with syntax identical to
3028 the regular trace command.
3030 ** Disconnected tracing
3032 It is now possible to detach GDB from the target while it is running
3033 a trace experiment, then reconnect later to see how the experiment
3034 is going. In addition, a new variable disconnected-tracing lets you
3035 tell the target agent whether to continue running a trace if the
3036 connection is lost unexpectedly.
3040 GDB now has the ability to save the trace buffer into a file, and
3041 then use that file as a target, similarly to you can do with
3042 corefiles. You can select trace frames, print data that was
3043 collected in them, and use tstatus to display the state of the
3044 tracing run at the moment that it was saved. To create a trace
3045 file, use "tsave <filename>", and to use it, do "target tfile
3048 ** Circular trace buffer
3050 You can ask the target agent to handle the trace buffer as a
3051 circular buffer, discarding the oldest trace frames to make room for
3052 newer ones, by setting circular-trace-buffer to on. This feature may
3053 not be available for all target agents.
3058 The disassemble command, when invoked with two arguments, now requires
3059 the arguments to be comma-separated.
3062 The info variables command now displays variable definitions. Files
3063 which only declare a variable are not shown.
3066 The source command is now capable of sourcing Python scripts.
3067 This feature is dependent on the debugger being build with Python
3070 Related to this enhancement is also the introduction of a new command
3071 "set script-extension" (see below).
3073 * New commands (for set/show, see "New options" below)
3075 record save [<FILENAME>]
3076 Save a file (in core file format) containing the process record
3077 execution log for replay debugging at a later time.
3079 record restore <FILENAME>
3080 Restore the process record execution log that was saved at an
3081 earlier time, for replay debugging.
3083 add-inferior [-copies <N>] [-exec <FILENAME>]
3086 clone-inferior [-copies <N>] [ID]
3087 Make a new inferior ready to execute the same program another
3088 inferior has loaded.
3093 maint info program-spaces
3094 List the program spaces loaded into GDB.
3096 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3097 show remote interrupt-sequence
3098 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3099 as the sequence to the remote target in order to interrupt the execution.
3100 Ctrl-C is a default. Some system prefers BREAK which is high level of
3101 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3102 Magic SysRq g. It is BREAK signal and character 'g'.
3104 set remote interrupt-on-connect [on | off]
3105 show remote interrupt-on-connect
3106 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3107 remote target when gdb connects to it. This is needed when you debug
3110 set remotebreak [on | off]
3112 Deprecated. Use "set/show remote interrupt-sequence" instead.
3114 tvariable $NAME [ = EXP ]
3115 Create or modify a trace state variable.
3118 List trace state variables and their values.
3120 delete tvariable $NAME ...
3121 Delete one or more trace state variables.
3124 Evaluate the given expressions without collecting anything into the
3125 trace buffer. (Valid in tracepoint actions only.)
3127 ftrace FN / FILE:LINE / *ADDR
3128 Define a fast tracepoint at the given function, line, or address.
3130 * New expression syntax
3132 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3133 GDB now parses 0b101010 identically with 42.
3137 set follow-exec-mode new|same
3138 show follow-exec-mode
3139 Control whether GDB reuses the same inferior across an exec call or
3140 creates a new one. This is useful to be able to restart the old
3141 executable after the inferior having done an exec call.
3143 set default-collect EXPR, ...
3144 show default-collect
3145 Define a list of expressions to be collected at each tracepoint.
3146 This is a useful way to ensure essential items are not overlooked,
3147 such as registers or a critical global variable.
3149 set disconnected-tracing
3150 show disconnected-tracing
3151 If set to 1, the target is instructed to continue tracing if it
3152 loses its connection to GDB. If 0, the target is to stop tracing
3155 set circular-trace-buffer
3156 show circular-trace-buffer
3157 If set to on, the target is instructed to use a circular trace buffer
3158 and discard the oldest trace frames instead of stopping the trace due
3159 to a full trace buffer. If set to off, the trace stops when the buffer
3160 fills up. Some targets may not support this.
3162 set script-extension off|soft|strict
3163 show script-extension
3164 If set to "off", the debugger does not perform any script language
3165 recognition, and all sourced files are assumed to be GDB scripts.
3166 If set to "soft" (the default), files are sourced according to
3167 filename extension, falling back to GDB scripts if the first
3169 If set to "strict", files are sourced according to filename extension.
3171 set ada trust-PAD-over-XVS on|off
3172 show ada trust-PAD-over-XVS
3173 If off, activate a workaround against a bug in the debugging information
3174 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3175 the GCC sources for more information about the GNAT encoding and
3176 PAD types in particular). It is always safe to set this option to
3177 off, but this introduces a slight performance penalty. The default
3180 * Python API Improvements
3182 ** GDB provides the new class gdb.LazyString. This is useful in
3183 some pretty-printing cases. The new method gdb.Value.lazy_string
3184 provides a simple way to create objects of this type.
3186 ** The fields returned by gdb.Type.fields now have an
3187 `is_base_class' attribute.
3189 ** The new method gdb.Type.range returns the range of an array type.
3191 ** The new method gdb.parse_and_eval can be used to parse and
3192 evaluate an expression.
3194 * New remote packets
3197 Define a trace state variable.
3200 Get the current value of a trace state variable.
3203 Set desired tracing behavior upon disconnection.
3206 Set the trace buffer to be linear or circular.
3209 Get data about the tracepoints currently in use.
3213 Process record now works correctly with hardware watchpoints.
3215 Multiple bug fixes have been made to the mips-irix port, making it
3216 much more reliable. In particular:
3217 - Debugging threaded applications is now possible again. Previously,
3218 GDB would hang while starting the program, or while waiting for
3219 the program to stop at a breakpoint.
3220 - Attaching to a running process no longer hangs.
3221 - An error occurring while loading a core file has been fixed.
3222 - Changing the value of the PC register now works again. This fixes
3223 problems observed when using the "jump" command, or when calling
3224 a function from GDB, or even when assigning a new value to $pc.
3225 - With the "finish" and "return" commands, the return value for functions
3226 returning a small array is now correctly printed.
3227 - It is now possible to break on shared library code which gets executed
3228 during a shared library init phase (code executed while executing
3229 their .init section). Previously, the breakpoint would have no effect.
3230 - GDB is now able to backtrace through the signal handler for
3231 non-threaded programs.
3233 PIE (Position Independent Executable) programs debugging is now supported.
3234 This includes debugging execution of PIC (Position Independent Code) shared
3235 libraries although for that, it should be possible to run such libraries as an
3238 *** Changes in GDB 7.0
3240 * GDB now has an interface for JIT compilation. Applications that
3241 dynamically generate code can create symbol files in memory and register
3242 them with GDB. For users, the feature should work transparently, and
3243 for JIT developers, the interface is documented in the GDB manual in the
3244 "JIT Compilation Interface" chapter.
3246 * Tracepoints may now be conditional. The syntax is as for
3247 breakpoints; either an "if" clause appended to the "trace" command,
3248 or the "condition" command is available. GDB sends the condition to
3249 the target for evaluation using the same bytecode format as is used
3250 for tracepoint actions.
3252 * The disassemble command now supports: an optional /r modifier, print the
3253 raw instructions in hex as well as in symbolic form, and an optional /m
3254 modifier to print mixed source+assembly.
3256 * Process record and replay
3258 In a architecture environment that supports ``process record and
3259 replay'', ``process record and replay'' target can record a log of
3260 the process execution, and replay it with both forward and reverse
3263 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3264 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3265 set execution-direction {forward|reverse}, for targets that support
3268 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3269 feature is available with a native GDB running on kernel version
3272 * GDB now has support for multi-byte and wide character sets on the
3273 target. Strings whose character type is wchar_t, char16_t, or
3274 char32_t are now correctly printed. GDB supports wide- and unicode-
3275 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3276 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3277 `printf'. This feature requires iconv to work properly; if your
3278 system does not have a working iconv, GDB can use GNU libiconv. See
3279 the installation instructions for more information.
3281 * GDB now supports automatic retrieval of shared library files from
3282 remote targets. To use this feature, specify a system root that begins
3283 with the `remote:' prefix, either via the `set sysroot' command or via
3284 the `--with-sysroot' configure-time option.
3286 * "info sharedlibrary" now takes an optional regex of libraries to show,
3287 and it now reports if a shared library has no debugging information.
3289 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3290 now complete on file names.
3292 * When completing in expressions, gdb will attempt to limit
3293 completions to allowable structure or union fields, where appropriate.
3294 For instance, consider:
3296 # struct example { int f1; double f2; };
3297 # struct example variable;
3300 If the user types TAB at the end of this command line, the available
3301 completions will be "f1" and "f2".
3303 * Inlined functions are now supported. They show up in backtraces, and
3304 the "step", "next", and "finish" commands handle them automatically.
3306 * GDB now supports the token-splicing (##) and stringification (#)
3307 operators when expanding macros. It also supports variable-arity
3310 * GDB now supports inspecting extra signal information, exported by
3311 the new $_siginfo convenience variable. The feature is currently
3312 implemented on linux ARM, i386 and amd64.
3314 * GDB can now display the VFP floating point registers and NEON vector
3315 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3316 can provide these registers (requires Linux 2.6.30 or later). Remote
3317 and simulator targets may also provide them.
3319 * New remote packets
3322 Search memory for a sequence of bytes.
3325 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3326 operation over reliable transport links. Use of this packet is
3327 controlled by the `set remote noack-packet' command.
3330 Kill the process with the specified process ID. Use this in preference
3331 to `k' when multiprocess protocol extensions are supported.
3334 Obtains additional operating system information
3338 Read or write additional signal information.
3340 * Removed remote protocol undocumented extension
3342 An undocumented extension to the remote protocol's `S' stop reply
3343 packet that permited the stub to pass a process id was removed.
3344 Remote servers should use the `T' stop reply packet instead.
3346 * GDB now supports multiple function calling conventions according to the
3347 DWARF-2 DW_AT_calling_convention function attribute.
3349 * The SH target utilizes the aforementioned change to distinguish between gcc
3350 and Renesas calling convention. It also adds the new CLI commands
3351 `set/show sh calling-convention'.
3353 * GDB can now read compressed debug sections, as produced by GNU gold
3354 with the --compress-debug-sections=zlib flag.
3356 * 64-bit core files are now supported on AIX.
3358 * Thread switching is now supported on Tru64.
3360 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3361 which will be allocated using malloc later in program execution.
3363 * The qXfer:libraries:read remote procotol packet now allows passing a
3364 list of section offsets.
3366 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3367 conditions handling signals delivered during attach or thread creation
3368 have also been fixed.
3370 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3371 From the user's standpoint, all unqualified instances of True and False
3372 are treated as the standard definitions, regardless of context.
3374 * GDB now parses C++ symbol and type names more flexibly. For
3377 template<typename T> class C { };
3380 GDB will now correctly handle all of:
3382 ptype C<char const *>
3383 ptype C<char const*>
3384 ptype C<const char *>
3385 ptype C<const char*>
3387 * New features in the GDB remote stub, gdbserver
3389 - The "--wrapper" command-line argument tells gdbserver to use a
3390 wrapper program to launch programs for debugging.
3392 - On PowerPC and S/390 targets, it is now possible to use a single
3393 gdbserver executable to debug both 32-bit and 64-bit programs.
3394 (This requires gdbserver itself to be built as a 64-bit executable.)
3396 - gdbserver uses the new noack protocol mode for TCP connections to
3397 reduce communications latency, if also supported and enabled in GDB.
3399 - Support for the sparc64-linux-gnu target is now included in
3402 - The amd64-linux build of gdbserver now supports debugging both
3403 32-bit and 64-bit programs.
3405 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3406 now support hardware watchpoints, and will use them automatically
3411 GDB now has support for scripting using Python. Whether this is
3412 available is determined at configure time.
3414 New GDB commands can now be written in Python.
3416 * Ada tasking support
3418 Ada tasks can now be inspected in GDB. The following commands have
3422 Print the list of Ada tasks.
3424 Print detailed information about task number N.
3426 Print the task number of the current task.
3428 Switch the context of debugging to task number N.
3430 * Support for user-defined prefixed commands. The "define" command can
3431 add new commands to existing prefixes, e.g. "target".
3433 * Multi-inferior, multi-process debugging.
3435 GDB now has generalized support for multi-inferior debugging. See
3436 "Debugging Multiple Inferiors" in the manual for more information.
3437 Although availability still depends on target support, the command
3438 set is more uniform now. The GNU/Linux specific multi-forks support
3439 has been migrated to this new framework. This implied some user
3440 visible changes; see "New commands" and also "Removed commands"
3443 * Target descriptions can now describe the target OS ABI. See the
3444 "Target Description Format" section in the user manual for more
3447 * Target descriptions can now describe "compatible" architectures
3448 to indicate that the target can execute applications for a different
3449 architecture in addition to those for the main target architecture.
3450 See the "Target Description Format" section in the user manual for
3453 * Multi-architecture debugging.
3455 GDB now includes general supports for debugging applications on
3456 hybrid systems that use more than one single processor architecture
3457 at the same time. Each such hybrid architecture still requires
3458 specific support to be added. The only hybrid architecture supported
3459 in this version of GDB is the Cell Broadband Engine.
3461 * GDB now supports integrated debugging of Cell/B.E. applications that
3462 use both the PPU and SPU architectures. To enable support for hybrid
3463 Cell/B.E. debugging, you need to configure GDB to support both the
3464 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3465 --enable-targets configure option.
3467 * Non-stop mode debugging.
3469 For some targets, GDB now supports an optional mode of operation in
3470 which you can examine stopped threads while other threads continue
3471 to execute freely. This is referred to as non-stop mode, with the
3472 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3473 section in the user manual for more information.
3475 To be able to support remote non-stop debugging, a remote stub needs
3476 to implement the non-stop mode remote protocol extensions, as
3477 described in the "Remote Non-Stop" section of the user manual. The
3478 GDB remote stub, gdbserver, has been adjusted to support these
3479 extensions on linux targets.
3481 * New commands (for set/show, see "New options" below)
3483 catch syscall [NAME(S) | NUMBER(S)]
3484 Catch system calls. Arguments, which should be names of system
3485 calls or their numbers, mean catch only those syscalls. Without
3486 arguments, every syscall will be caught. When the inferior issues
3487 any of the specified syscalls, GDB will stop and announce the system
3488 call, both when it is called and when its call returns. This
3489 feature is currently available with a native GDB running on the
3490 Linux Kernel, under the following architectures: x86, x86_64,
3491 PowerPC and PowerPC64.
3493 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3495 Search memory for a sequence of bytes.
3497 maint set python print-stack
3498 maint show python print-stack
3499 Show a stack trace when an error is encountered in a Python script.
3502 Invoke CODE by passing it to the Python interpreter.
3507 These allow macros to be defined, undefined, and listed
3511 Show operating system information about processes.
3514 List the inferiors currently under GDB's control.
3517 Switch focus to inferior number NUM.
3520 Detach from inferior number NUM.
3523 Kill inferior number NUM.
3527 set spu stop-on-load
3528 show spu stop-on-load
3529 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3531 set spu auto-flush-cache
3532 show spu auto-flush-cache
3533 Control whether to automatically flush the software-managed cache
3534 during Cell/B.E. debugging.
3536 set sh calling-convention
3537 show sh calling-convention
3538 Control the calling convention used when calling SH target functions.
3541 show debug timestamp
3542 Control display of timestamps with GDB debugging output.
3544 set disassemble-next-line
3545 show disassemble-next-line
3546 Control display of disassembled source lines or instructions when
3549 set remote noack-packet
3550 show remote noack-packet
3551 Set/show the use of remote protocol QStartNoAckMode packet. See above
3552 under "New remote packets."
3554 set remote query-attached-packet
3555 show remote query-attached-packet
3556 Control use of remote protocol `qAttached' (query-attached) packet.
3558 set remote read-siginfo-object
3559 show remote read-siginfo-object
3560 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3563 set remote write-siginfo-object
3564 show remote write-siginfo-object
3565 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3568 set remote reverse-continue
3569 show remote reverse-continue
3570 Control use of remote protocol 'bc' (reverse-continue) packet.
3572 set remote reverse-step
3573 show remote reverse-step
3574 Control use of remote protocol 'bs' (reverse-step) packet.
3576 set displaced-stepping
3577 show displaced-stepping
3578 Control displaced stepping mode. Displaced stepping is a way to
3579 single-step over breakpoints without removing them from the debuggee.
3580 Also known as "out-of-line single-stepping".
3583 show debug displaced
3584 Control display of debugging info for displaced stepping.
3586 maint set internal-error
3587 maint show internal-error
3588 Control what GDB does when an internal error is detected.
3590 maint set internal-warning
3591 maint show internal-warning
3592 Control what GDB does when an internal warning is detected.
3597 Use a wrapper program to launch programs for debugging.
3599 set multiple-symbols (all|ask|cancel)
3600 show multiple-symbols
3601 The value of this variable can be changed to adjust the debugger behavior
3602 when an expression or a breakpoint location contains an ambiguous symbol
3603 name (an overloaded function name, for instance).
3605 set breakpoint always-inserted
3606 show breakpoint always-inserted
3607 Keep breakpoints always inserted in the target, as opposed to inserting
3608 them when resuming the target, and removing them when the target stops.
3609 This option can improve debugger performance on slow remote targets.
3611 set arm fallback-mode (arm|thumb|auto)
3612 show arm fallback-mode
3613 set arm force-mode (arm|thumb|auto)
3615 These commands control how ARM GDB determines whether instructions
3616 are ARM or Thumb. The default for both settings is auto, which uses
3617 the current CPSR value for instructions without symbols; previous
3618 versions of GDB behaved as if "set arm fallback-mode arm".
3620 set disable-randomization
3621 show disable-randomization
3622 Standalone programs run with the virtual address space randomization enabled
3623 by default on some platforms. This option keeps the addresses stable across
3624 multiple debugging sessions.
3628 Control whether other threads are stopped or not when some thread hits
3633 Requests that asynchronous execution is enabled in the target, if available.
3634 In this case, it's possible to resume target in the background, and interact
3635 with GDB while the target is running. "show target-async" displays the
3636 current state of asynchronous execution of the target.
3638 set target-wide-charset
3639 show target-wide-charset
3640 The target-wide-charset is the name of the character set that GDB
3641 uses when printing characters whose type is wchar_t.
3643 set tcp auto-retry (on|off)
3645 set tcp connect-timeout
3646 show tcp connect-timeout
3647 These commands allow GDB to retry failed TCP connections to a remote stub
3648 with a specified timeout period; this is useful if the stub is launched
3649 in parallel with GDB but may not be ready to accept connections immediately.
3651 set libthread-db-search-path
3652 show libthread-db-search-path
3653 Control list of directories which GDB will search for appropriate
3656 set schedule-multiple (on|off)
3657 show schedule-multiple
3658 Allow GDB to resume all threads of all processes or only threads of
3659 the current process.
3663 Use more aggressive caching for accesses to the stack. This improves
3664 performance of remote debugging (particularly backtraces) without
3665 affecting correctness.
3667 set interactive-mode (on|off|auto)
3668 show interactive-mode
3669 Control whether GDB runs in interactive mode (on) or not (off).
3670 When in interactive mode, GDB waits for the user to answer all
3671 queries. Otherwise, GDB does not wait and assumes the default
3672 answer. When set to auto (the default), GDB determines which
3673 mode to use based on the stdin settings.
3678 For program forks, this is replaced by the new more generic `info
3679 inferiors' command. To list checkpoints, you can still use the
3680 `info checkpoints' command, which was an alias for the `info forks'
3684 Replaced by the new `inferior' command. To switch between
3685 checkpoints, you can still use the `restart' command, which was an
3686 alias for the `fork' command.
3689 This is removed, since some targets don't have a notion of
3690 processes. To switch between processes, you can still use the
3691 `inferior' command using GDB's own inferior number.
3694 For program forks, this is replaced by the new more generic `kill
3695 inferior' command. To delete a checkpoint, you can still use the
3696 `delete checkpoint' command, which was an alias for the `delete
3700 For program forks, this is replaced by the new more generic `detach
3701 inferior' command. To detach a checkpoint, you can still use the
3702 `detach checkpoint' command, which was an alias for the `detach
3705 * New native configurations
3707 x86/x86_64 Darwin i[34567]86-*-darwin*
3709 x86_64 MinGW x86_64-*-mingw*
3713 Lattice Mico32 lm32-*
3714 x86 DICOS i[34567]86-*-dicos*
3715 x86_64 DICOS x86_64-*-dicos*
3718 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3719 (mingw32ce) debugging.
3725 These commands were actually not implemented on any target.
3727 *** Changes in GDB 6.8
3729 * New native configurations
3731 NetBSD/hppa hppa*-*netbsd*
3732 Xtensa GNU/Linux xtensa*-*-linux*
3736 NetBSD/hppa hppa*-*-netbsd*
3737 Xtensa GNU/Lunux xtensa*-*-linux*
3739 * Change in command line behavior -- corefiles vs. process ids.
3741 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3742 attaching to process NUMBER fails, GDB no longer attempts to open a
3743 core file named NUMBER. Attaching to a program using the -c option
3744 is no longer supported. Instead, use the '-p' or '--pid' options.
3746 * GDB can now be built as a native debugger for debugging Windows x86
3747 (mingw32) Portable Executable (PE) programs.
3749 * Pending breakpoints no longer change their number when their address
3752 * GDB now supports breakpoints with multiple locations,
3753 including breakpoints on C++ constructors, inside C++ templates,
3754 and in inlined functions.
3756 * GDB's ability to debug optimized code has been improved. GDB more
3757 accurately identifies function bodies and lexical blocks that occupy
3758 more than one contiguous range of addresses.
3760 * Target descriptions can now describe registers for PowerPC.
3762 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3763 registers on PowerPC targets.
3765 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3766 targets even when the libthread_db library is not available.
3768 * The GDB remote stub, gdbserver, now supports the new file transfer
3769 commands (remote put, remote get, and remote delete).
3771 * The GDB remote stub, gdbserver, now supports run and attach in
3772 extended-remote mode.
3774 * hppa*64*-*-hpux11* target broken
3775 The debugger is unable to start a program and fails with the following
3776 error: "Error trying to get information about dynamic linker".
3777 The gdb-6.7 release is also affected.
3779 * GDB now supports the --enable-targets= configure option to allow
3780 building a single GDB executable that supports multiple remote
3781 target architectures.
3783 * GDB now supports debugging C and C++ programs which use the
3784 Decimal Floating Point extension. In addition, the PowerPC target
3785 now has a set of pseudo-registers to inspect decimal float values
3786 stored in two consecutive float registers.
3788 * The -break-insert MI command can optionally create pending
3791 * Improved support for debugging Ada
3792 Many improvements to the Ada language support have been made. These
3794 - Better support for Ada2005 interface types
3795 - Improved handling of arrays and slices in general
3796 - Better support for Taft-amendment types
3797 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3799 - Improved command completion in Ada
3802 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3807 set print frame-arguments (all|scalars|none)
3808 show print frame-arguments
3809 The value of this variable can be changed to control which argument
3810 values should be printed by the debugger when displaying a frame.
3815 Transfer files to and from a remote target, and delete remote files.
3822 Transfer files to and from a remote target, and delete remote files.
3824 * New remote packets
3831 Open, close, read, write, and delete files on the remote system.
3834 Attach to an existing process on the remote system, in extended-remote
3838 Run a new process on the remote system, in extended-remote mode.
3840 *** Changes in GDB 6.7
3842 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3843 bfd, libiberty and opcodes, as revealed by static analysis donated by
3844 Coverity, Inc. (http://scan.coverity.com).
3846 * When looking up multiply-defined global symbols, GDB will now prefer the
3847 symbol definition in the current shared library if it was built using the
3848 -Bsymbolic linker option.
3850 * When the Text User Interface (TUI) is not configured, GDB will now
3851 recognize the -tui command-line option and print a message that the TUI
3854 * The GDB remote stub, gdbserver, now has lower overhead for high
3855 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3857 * GDB for MIPS targets now autodetects whether a remote target provides
3858 32-bit or 64-bit register values.
3860 * Support for C++ member pointers has been improved.
3862 * GDB now understands XML target descriptions, which specify the
3863 target's overall architecture. GDB can read a description from
3864 a local file or over the remote serial protocol.
3866 * Vectors of single-byte data use a new integer type which is not
3867 automatically displayed as character or string data.
3869 * The /s format now works with the print command. It displays
3870 arrays of single-byte integers and pointers to single-byte integers
3873 * Target descriptions can now describe target-specific registers,
3874 for architectures which have implemented the support (currently
3875 only ARM, M68K, and MIPS).
3877 * GDB and the GDB remote stub, gdbserver, now support the XScale
3880 * The GDB remote stub, gdbserver, has been updated to support
3881 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3882 has been rewritten to use the standard GDB remote protocol.
3884 * GDB can now step into C++ functions which are called through thunks.
3886 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3888 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3889 layout. It also supports a TextSeg= and DataSeg= response when only
3890 segment base addresses (rather than offsets) are available.
3892 * The /i format now outputs any trailing branch delay slot instructions
3893 immediately following the last instruction within the count specified.
3895 * The GDB remote protocol "T" stop reply packet now supports a
3896 "library" response. Combined with the new "qXfer:libraries:read"
3897 packet, this response allows GDB to debug shared libraries on targets
3898 where the operating system manages the list of loaded libraries (e.g.
3899 Windows and SymbianOS).
3901 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3902 (DLLs) on Windows and Windows CE targets.
3904 * GDB now supports a faster verification that a .debug file matches its binary
3905 according to its build-id signature, if the signature is present.
3911 Enable or disable hardware flow control (RTS/CTS) on the serial port
3912 when debugging using remote targets.
3914 set mem inaccessible-by-default
3915 show mem inaccessible-by-default
3916 If the target supplies a memory map, for instance via the remote
3917 protocol's "qXfer:memory-map:read" packet, setting this variable
3918 prevents GDB from accessing memory outside the memory map. This
3919 is useful for targets with memory mapped registers or which react
3920 badly to accesses of unmapped address space.
3922 set breakpoint auto-hw
3923 show breakpoint auto-hw
3924 If the target supplies a memory map, for instance via the remote
3925 protocol's "qXfer:memory-map:read" packet, setting this variable
3926 lets GDB use hardware breakpoints automatically for memory regions
3927 where it can not use software breakpoints. This covers both the
3928 "break" command and internal breakpoints used for other commands
3929 including "next" and "finish".
3932 catch exception unhandled
3933 Stop the program execution when Ada exceptions are raised.
3936 Stop the program execution when an Ada assertion failed.
3940 Set an alternate system root for target files. This is a more
3941 general version of "set solib-absolute-prefix", which is now
3942 an alias to "set sysroot".
3945 Provide extended SPU facility status information. This set of
3946 commands is available only when debugging the Cell/B.E. SPU
3949 * New native configurations
3951 OpenBSD/sh sh*-*openbsd*
3954 unset tdesc filename
3956 Use the specified local file as an XML target description, and do
3957 not query the target for its built-in description.
3961 OpenBSD/sh sh*-*-openbsd*
3962 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3963 Toshiba Media Processor mep-elf
3965 * New remote packets
3968 Ignore the specified signals; pass them directly to the debugged program
3969 without stopping other threads or reporting them to GDB.
3971 qXfer:features:read:
3972 Read an XML target description from the target, which describes its
3977 Read or write contents of an spufs file on the target system. These
3978 packets are available only on the Cell/B.E. SPU architecture.
3980 qXfer:libraries:read:
3981 Report the loaded shared libraries. Combined with new "T" packet
3982 response, this packet allows GDB to debug shared libraries on
3983 targets where the operating system manages the list of loaded
3984 libraries (e.g. Windows and SymbianOS).
3988 Support for these obsolete configurations has been removed.
3996 i[34567]86-*-lynxos*
3997 i[34567]86-*-netware*
3998 i[34567]86-*-sco3.2v5*
3999 i[34567]86-*-sco3.2v4*
4001 i[34567]86-*-sysv4.2*
4004 i[34567]86-*-unixware2*
4005 i[34567]86-*-unixware*
4014 * Other removed features
4021 Various m68k-only ROM monitors.
4028 Various Renesas ROM monitors and debugging interfaces for SH and
4033 Support for a Macraigor serial interface to on-chip debugging.
4034 GDB does not directly support the newer parallel or USB
4039 A debug information format. The predecessor to DWARF 2 and
4040 DWARF 3, which are still supported.
4042 Support for the HP aCC compiler on HP-UX/PA-RISC
4044 SOM-encapsulated symbolic debugging information, automatic
4045 invocation of pxdb, and the aCC custom C++ ABI. This does not
4046 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4047 with aCC can still be debugged on an assembly level.
4049 MIPS ".pdr" sections
4051 A MIPS-specific format used to describe stack frame layout
4052 in debugging information.
4056 GDB could work with an older version of Guile to debug
4057 the interpreter and Scheme programs running in it.
4059 set mips stack-arg-size
4060 set mips saved-gpreg-size
4062 Use "set mips abi" to control parameter passing for MIPS.
4064 *** Changes in GDB 6.6
4069 Cell Broadband Engine SPU spu-elf
4071 * GDB can now be configured as a cross-debugger targeting native Windows
4072 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4073 running on a Windows system over TCP/IP to debug Windows programs.
4075 * The GDB remote stub, gdbserver, has been updated to support Windows and
4076 Cygwin debugging. Both single-threaded and multi-threaded programs are
4079 * The "set trust-readonly-sections" command works again. This command was
4080 broken in GDB 6.3, 6.4, and 6.5.
4082 * The "load" command now supports writing to flash memory, if the remote
4083 stub provides the required support.
4085 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4086 longer requires symbolic debug information (e.g. DWARF-2).
4091 unset substitute-path
4092 show substitute-path
4093 Manage a list of substitution rules that GDB uses to rewrite the name
4094 of the directories where the sources are located. This can be useful
4095 for instance when the sources were moved to a different location
4096 between compilation and debugging.
4100 Print each CLI command as it is executed. Each command is prefixed with
4101 a number of `+' symbols representing the nesting depth.
4102 The source command now has a `-v' option to enable the same feature.
4106 The ARM Demon monitor support (RDP protocol, "target rdp").
4108 Kernel Object Display, an embedded debugging feature which only worked with
4109 an obsolete version of Cisco IOS.
4111 The 'set download-write-size' and 'show download-write-size' commands.
4113 * New remote packets
4116 Tell a stub about GDB client features, and request remote target features.
4117 The first feature implemented is PacketSize, which allows the target to
4118 specify the size of packets it can handle - to minimize the number of
4119 packets required and improve performance when connected to a remote
4123 Fetch an OS auxilliary vector from the remote stub. This packet is a
4124 more efficient replacement for qPart:auxv:read.
4126 qXfer:memory-map:read:
4127 Fetch a memory map from the remote stub, including information about
4128 RAM, ROM, and flash memory devices.
4133 Erase and program a flash memory device.
4135 * Removed remote packets
4138 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4139 used it, and only gdbserver implemented it.
4141 *** Changes in GDB 6.5
4145 Renesas M32C/M16C m32c-elf
4147 Morpho Technologies ms1 ms1-elf
4151 init-if-undefined Initialize a convenience variable, but
4152 only if it doesn't already have a value.
4154 The following commands are presently only implemented for native GNU/Linux:
4156 checkpoint Save a snapshot of the program state.
4158 restart <n> Return the program state to a
4159 previously saved state.
4161 info checkpoints List currently saved checkpoints.
4163 delete-checkpoint <n> Delete a previously saved checkpoint.
4165 set|show detach-on-fork Tell gdb whether to detach from a newly
4166 forked process, or to keep debugging it.
4168 info forks List forks of the user program that
4169 are available to be debugged.
4171 fork <n> Switch to debugging one of several
4172 forks of the user program that are
4173 available to be debugged.
4175 delete-fork <n> Delete a fork from the list of forks
4176 that are available to be debugged (and
4177 kill the forked process).
4179 detach-fork <n> Delete a fork from the list of forks
4180 that are available to be debugged (and
4181 allow the process to continue).
4185 Morpho Technologies ms2 ms1-elf
4187 * Improved Windows host support
4189 GDB now builds as a cross debugger hosted on i686-mingw32, including
4190 native console support, and remote communications using either
4191 network sockets or serial ports.
4193 * Improved Modula-2 language support
4195 GDB can now print most types in the Modula-2 syntax. This includes:
4196 basic types, set types, record types, enumerated types, range types,
4197 pointer types and ARRAY types. Procedure var parameters are correctly
4198 printed and hexadecimal addresses and character constants are also
4199 written in the Modula-2 syntax. Best results can be obtained by using
4200 GNU Modula-2 together with the -gdwarf-2 command line option.
4204 The ARM rdi-share module.
4206 The Netware NLM debug server.
4208 *** Changes in GDB 6.4
4210 * New native configurations
4212 OpenBSD/arm arm*-*-openbsd*
4213 OpenBSD/mips64 mips64-*-openbsd*
4217 Morpho Technologies ms1 ms1-elf
4219 * New command line options
4221 --batch-silent As for --batch, but totally silent.
4222 --return-child-result The debugger will exist with the same value
4223 the child (debugged) program exited with.
4224 --eval-command COMMAND, -ex COMMAND
4225 Execute a single GDB CLI command. This may be
4226 specified multiple times and in conjunction
4227 with the --command (-x) option.
4229 * Deprecated commands removed
4231 The following commands, that were deprecated in 2000, have been
4235 set|show arm disassembly-flavor set|show arm disassembler
4236 othernames set arm disassembler
4237 set|show remotedebug set|show debug remote
4238 set|show archdebug set|show debug arch
4239 set|show eventdebug set|show debug event
4242 * New BSD user-level threads support
4244 It is now possible to debug programs using the user-level threads
4245 library on OpenBSD and FreeBSD. Currently supported (target)
4248 FreeBSD/amd64 x86_64-*-freebsd*
4249 FreeBSD/i386 i386-*-freebsd*
4250 OpenBSD/i386 i386-*-openbsd*
4252 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4253 are not yet supported.
4255 * New support for Matsushita MN10300 w/sim added
4256 (Work in progress). mn10300-elf.
4258 * REMOVED configurations and files
4260 VxWorks and the XDR protocol *-*-vxworks
4261 Motorola MCORE mcore-*-*
4262 National Semiconductor NS32000 ns32k-*-*
4264 * New "set print array-indexes" command
4266 After turning this setting "on", GDB prints the index of each element
4267 when displaying arrays. The default is "off" to preserve the previous
4270 * VAX floating point support
4272 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4274 * User-defined command support
4276 In addition to using $arg0..$arg9 for argument passing, it is now possible
4277 to use $argc to determine now many arguments have been passed. See the
4278 section on user-defined commands in the user manual for more information.
4280 *** Changes in GDB 6.3:
4282 * New command line option
4284 GDB now accepts -l followed by a number to set the timeout for remote
4287 * GDB works with GCC -feliminate-dwarf2-dups
4289 GDB now supports a more compact representation of DWARF-2 debug
4290 information using DW_FORM_ref_addr references. These are produced
4291 by GCC with the option -feliminate-dwarf2-dups and also by some
4292 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4293 to use -feliminate-dwarf2-dups.
4295 * Internationalization
4297 When supported by the host system, GDB will be built with
4298 internationalization (libintl). The task of marking up the sources is
4299 continued, we're looking forward to our first translation.
4303 Initial support for debugging programs compiled with the GNAT
4304 implementation of the Ada programming language has been integrated
4305 into GDB. In this release, support is limited to expression evaluation.
4307 * New native configurations
4309 GNU/Linux/m32r m32r-*-linux-gnu
4313 GDB's remote protocol now includes support for the 'p' packet. This
4314 packet is used to fetch individual registers from a remote inferior.
4316 * END-OF-LIFE registers[] compatibility module
4318 GDB's internal register infrastructure has been completely rewritten.
4319 The new infrastructure making possible the implementation of key new
4320 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4323 GDB 6.3 will be the last release to include the the registers[]
4324 compatibility module that allowed out-of-date configurations to
4325 continue to work. This change directly impacts the following
4335 powerpc bdm protocol
4337 Unless there is activity to revive these configurations, they will be
4338 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4340 * OBSOLETE configurations and files
4342 Configurations that have been declared obsolete in this release have
4343 been commented out. Unless there is activity to revive these
4344 configurations, the next release of GDB will have their sources
4345 permanently REMOVED.
4354 *** Changes in GDB 6.2.1:
4356 * MIPS `break main; run' gave an heuristic-fence-post warning
4358 When attempting to run even a simple program, a warning about
4359 heuristic-fence-post being hit would be reported. This problem has
4362 * MIPS IRIX 'long double' crashed GDB
4364 When examining a long double variable, GDB would get a segmentation
4365 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4366 IRIX long double values).
4370 A bug in the VAX stack code was causing problems with the "next"
4371 command. This problem has been fixed.
4373 *** Changes in GDB 6.2:
4375 * Fix for ``many threads''
4377 On GNU/Linux systems that use the NPTL threads library, a program
4378 rapidly creating and deleting threads would confuse GDB leading to the
4381 ptrace: No such process.
4382 thread_db_get_info: cannot get thread info: generic error
4384 This problem has been fixed.
4386 * "-async" and "-noasync" options removed.
4388 Support for the broken "-noasync" option has been removed (it caused
4391 * New ``start'' command.
4393 This command runs the program until the begining of the main procedure.
4395 * New BSD Kernel Data Access Library (libkvm) interface
4397 Using ``target kvm'' it is now possible to debug kernel core dumps and
4398 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4399 platforms. Currently supported (native-only) configurations are:
4401 FreeBSD/amd64 x86_64-*-freebsd*
4402 FreeBSD/i386 i?86-*-freebsd*
4403 NetBSD/i386 i?86-*-netbsd*
4404 NetBSD/m68k m68*-*-netbsd*
4405 NetBSD/sparc sparc-*-netbsd*
4406 OpenBSD/amd64 x86_64-*-openbsd*
4407 OpenBSD/i386 i?86-*-openbsd*
4408 OpenBSD/m68k m68*-openbsd*
4409 OpenBSD/sparc sparc-*-openbsd*
4411 * Signal trampoline code overhauled
4413 Many generic problems with GDB's signal handling code have been fixed.
4414 These include: backtraces through non-contiguous stacks; recognition
4415 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4416 call; backtrace through a signal trampoline; step into and out of
4417 signal handlers; and single-stepping in the signal trampoline.
4419 Please note that kernel bugs are a limiting factor here. These
4420 features have been shown to work on an s390 GNU/Linux system that
4421 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4423 * Cygwin support for DWARF 2 added.
4425 * New native configurations
4427 GNU/Linux/hppa hppa*-*-linux*
4428 OpenBSD/hppa hppa*-*-openbsd*
4429 OpenBSD/m68k m68*-*-openbsd*
4430 OpenBSD/m88k m88*-*-openbsd*
4431 OpenBSD/powerpc powerpc-*-openbsd*
4432 NetBSD/vax vax-*-netbsd*
4433 OpenBSD/vax vax-*-openbsd*
4435 * END-OF-LIFE frame compatibility module
4437 GDB's internal frame infrastructure has been completely rewritten.
4438 The new infrastructure making it possible to support key new features
4439 including DWARF 2 Call Frame Information. To aid in the task of
4440 migrating old configurations to this new infrastructure, a
4441 compatibility module, that allowed old configurations to continue to
4442 work, was also included.
4444 GDB 6.2 will be the last release to include this frame compatibility
4445 module. This change directly impacts the following configurations:
4455 Unless there is activity to revive these configurations, they will be
4456 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4458 * REMOVED configurations and files
4460 Sun 3, running SunOS 3 m68*-*-sunos3*
4461 Sun 3, running SunOS 4 m68*-*-sunos4*
4462 Sun 2, running SunOS 3 m68000-*-sunos3*
4463 Sun 2, running SunOS 4 m68000-*-sunos4*
4464 Motorola 680x0 running LynxOS m68*-*-lynxos*
4465 AT&T 3b1/Unix pc m68*-att-*
4466 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4467 decstation mips-dec-* mips-little-*
4468 riscos mips-*-riscos* mips-*-sysv*
4469 sonymips mips-sony-*
4470 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4472 *** Changes in GDB 6.1.1:
4474 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4476 The TUI (Text-mode User Interface) is now built as part of a default
4477 GDB configuration. It is enabled by either selecting the TUI with the
4478 command line option "-i=tui" or by running the separate "gdbtui"
4479 program. For more information on the TUI, see the manual "Debugging
4482 * Pending breakpoint support (also included in GDB 6.1)
4484 Support has been added to allow you to specify breakpoints in shared
4485 libraries that have not yet been loaded. If a breakpoint location
4486 cannot be found, and the "breakpoint pending" option is set to auto,
4487 GDB queries you if you wish to make the breakpoint pending on a future
4488 shared-library load. If and when GDB resolves the breakpoint symbol,
4489 the pending breakpoint is removed as one or more regular breakpoints
4492 Pending breakpoints are very useful for GCJ Java debugging.
4494 * Fixed ISO-C build problems
4496 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4497 non ISO-C code that stopped them being built using a more strict ISO-C
4498 compiler (e.g., IBM's C compiler).
4500 * Fixed build problem on IRIX 5
4502 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4503 wasn't able to compile compile on an IRIX 5 system.
4505 * Added execute permission to gdb/gdbserver/configure
4507 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4508 permission. This bug would cause configure to fail on a number of
4509 systems (Solaris, IRIX). Ref: server/519.
4511 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4513 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4514 has been updated to use constant array sizes.
4516 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4518 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4519 its generated DWARF Call Frame Info. This encoding was causing GDB to
4520 panic, that panic has been fixed. Ref: gdb/1628.
4522 * Fixed a problem when examining parameters in shared library code.
4524 When examining parameters in optimized shared library code generated
4525 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4526 not available''. GDB now correctly displays the variable's value.
4528 *** Changes in GDB 6.1:
4530 * Removed --with-mmalloc
4532 Support for the mmalloc memory manager has been removed, as it
4533 conflicted with the internal gdb byte cache.
4535 * Changes in AMD64 configurations
4537 The AMD64 target now includes the %cs and %ss registers. As a result
4538 the AMD64 remote protocol has changed; this affects the floating-point
4539 and SSE registers. If you rely on those registers for your debugging,
4540 you should upgrade gdbserver on the remote side.
4542 * Revised SPARC target
4544 The SPARC target has been completely revised, incorporating the
4545 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4546 support for LynxOS and SunOS 4 has been dropped. Calling functions
4547 from within GDB on operating systems with a non-executable stack
4548 (Solaris, OpenBSD) now works.
4552 GDB has a new C++ demangler which does a better job on the mangled
4553 names generated by current versions of g++. It also runs faster, so
4554 with this and other changes gdb should now start faster on large C++
4557 * DWARF 2 Location Expressions
4559 GDB support for location expressions has been extended to support function
4560 arguments and frame bases. Older versions of GDB could crash when they
4563 * C++ nested types and namespaces
4565 GDB's support for nested types and namespaces in C++ has been
4566 improved, especially if you use the DWARF 2 debugging format. (This
4567 is the default for recent versions of GCC on most platforms.)
4568 Specifically, if you have a class "Inner" defined within a class or
4569 namespace "Outer", then GDB realizes that the class's name is
4570 "Outer::Inner", not simply "Inner". This should greatly reduce the
4571 frequency of complaints about not finding RTTI symbols. In addition,
4572 if you are stopped at inside of a function defined within a namespace,
4573 GDB modifies its name lookup accordingly.
4575 * New native configurations
4577 NetBSD/amd64 x86_64-*-netbsd*
4578 OpenBSD/amd64 x86_64-*-openbsd*
4579 OpenBSD/alpha alpha*-*-openbsd*
4580 OpenBSD/sparc sparc-*-openbsd*
4581 OpenBSD/sparc64 sparc64-*-openbsd*
4583 * New debugging protocols
4585 M32R with SDI protocol m32r-*-elf*
4587 * "set prompt-escape-char" command deleted.
4589 The command "set prompt-escape-char" has been deleted. This command,
4590 and its very obscure effet on GDB's prompt, was never documented,
4591 tested, nor mentioned in the NEWS file.
4593 * OBSOLETE configurations and files
4595 Configurations that have been declared obsolete in this release have
4596 been commented out. Unless there is activity to revive these
4597 configurations, the next release of GDB will have their sources
4598 permanently REMOVED.
4600 Sun 3, running SunOS 3 m68*-*-sunos3*
4601 Sun 3, running SunOS 4 m68*-*-sunos4*
4602 Sun 2, running SunOS 3 m68000-*-sunos3*
4603 Sun 2, running SunOS 4 m68000-*-sunos4*
4604 Motorola 680x0 running LynxOS m68*-*-lynxos*
4605 AT&T 3b1/Unix pc m68*-att-*
4606 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4607 decstation mips-dec-* mips-little-*
4608 riscos mips-*-riscos* mips-*-sysv*
4609 sonymips mips-sony-*
4610 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4612 * REMOVED configurations and files
4614 SGI Irix-4.x mips-sgi-irix4 or iris4
4615 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4616 Z8000 simulator z8k-zilog-none or z8ksim
4617 Matsushita MN10200 w/simulator mn10200-*-*
4618 H8/500 simulator h8500-hitachi-hms or h8500hms
4619 HP/PA running BSD hppa*-*-bsd*
4620 HP/PA running OSF/1 hppa*-*-osf*
4621 HP/PA Pro target hppa*-*-pro*
4622 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4623 386BSD i[3456]86-*-bsd*
4624 Sequent family i[3456]86-sequent-sysv4*
4625 i[3456]86-sequent-sysv*
4626 i[3456]86-sequent-bsd*
4627 SPARC running LynxOS sparc-*-lynxos*
4628 SPARC running SunOS 4 sparc-*-sunos4*
4629 Tsqware Sparclet sparclet-*-*
4630 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4632 *** Changes in GDB 6.0:
4636 Support for debugging the Objective-C programming language has been
4637 integrated into GDB.
4639 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4641 DWARF 2's Call Frame Information makes available compiler generated
4642 information that more exactly describes the program's run-time stack.
4643 By using this information, GDB is able to provide more robust stack
4646 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4647 have been updated to use a new backtrace mechanism which includes
4648 DWARF 2 CFI support.
4652 GDB's remote protocol has been extended to include support for hosted
4653 file I/O (where the remote target uses GDB's file system). See GDB's
4654 remote protocol documentation for details.
4656 * All targets using the new architecture framework.
4658 All of GDB's targets have been updated to use the new internal
4659 architecture framework. The way is now open for future GDB releases
4660 to include cross-architecture native debugging support (i386 on amd64,
4663 * GNU/Linux's Thread Local Storage (TLS)
4665 GDB now includes support for for the GNU/Linux implementation of
4666 per-thread variables.
4668 * GNU/Linux's Native POSIX Thread Library (NPTL)
4670 GDB's thread code has been updated to work with either the new
4671 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4673 * Separate debug info.
4675 GDB, in conjunction with BINUTILS, now supports a mechanism for
4676 automatically loading debug information from a separate file. Instead
4677 of shipping full debug and non-debug versions of system libraries,
4678 system integrators can now instead ship just the stripped libraries
4679 and optional debug files.
4681 * DWARF 2 Location Expressions
4683 DWARF 2 Location Expressions allow the compiler to more completely
4684 describe the location of variables (even in optimized code) to the
4687 GDB now includes preliminary support for location expressions (support
4688 for DW_OP_piece is still missing).
4692 A number of long standing bugs that caused GDB to die while starting a
4693 Java application have been fixed. GDB's Java support is now
4694 considered "useable".
4696 * GNU/Linux support for fork, vfork, and exec.
4698 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4699 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4702 * GDB supports logging output to a file
4704 There are two new commands, "set logging" and "show logging", which can be
4705 used to capture GDB's output to a file.
4707 * The meaning of "detach" has changed for gdbserver
4709 The "detach" command will now resume the application, as documented. To
4710 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4713 * d10v, m68hc11 `regs' command deprecated
4715 The `info registers' command has been updated so that it displays the
4716 registers using a format identical to the old `regs' command.
4720 A new command, "maint set profile on/off", has been added. This command can
4721 be used to enable or disable profiling while running GDB, to profile a
4722 session or a set of commands. In addition there is a new configure switch,
4723 "--enable-profiling", which will cause GDB to be compiled with profiling
4724 data, for more informative profiling results.
4726 * Default MI syntax changed to "mi2".
4728 The default MI (machine interface) syntax, enabled by the command line
4729 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4730 "mi1", can be enabled by specifying the option "-i=mi1".
4732 Support for the original "mi0" syntax (included in GDB 5.0) has been
4735 Fix for gdb/192: removed extraneous space when displaying frame level.
4736 Fix for gdb/672: update changelist is now output in mi list format.
4737 Fix for gdb/702: a -var-assign that updates the value now shows up
4738 in a subsequent -var-update.
4740 * New native configurations.
4742 FreeBSD/amd64 x86_64-*-freebsd*
4744 * Multi-arched targets.
4746 HP/PA HPUX11 hppa*-*-hpux*
4747 Renesas M32R/D w/simulator m32r-*-elf*
4749 * OBSOLETE configurations and files
4751 Configurations that have been declared obsolete in this release have
4752 been commented out. Unless there is activity to revive these
4753 configurations, the next release of GDB will have their sources
4754 permanently REMOVED.
4756 Z8000 simulator z8k-zilog-none or z8ksim
4757 Matsushita MN10200 w/simulator mn10200-*-*
4758 H8/500 simulator h8500-hitachi-hms or h8500hms
4759 HP/PA running BSD hppa*-*-bsd*
4760 HP/PA running OSF/1 hppa*-*-osf*
4761 HP/PA Pro target hppa*-*-pro*
4762 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4763 Sequent family i[3456]86-sequent-sysv4*
4764 i[3456]86-sequent-sysv*
4765 i[3456]86-sequent-bsd*
4766 Tsqware Sparclet sparclet-*-*
4767 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4769 * REMOVED configurations and files
4772 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4773 IBM AIX PS/2 i[3456]86-*-aix
4774 i386 running Mach 3.0 i[3456]86-*-mach3*
4775 i386 running Mach i[3456]86-*-mach*
4776 i386 running OSF/1 i[3456]86-*osf1mk*
4777 HP/Apollo 68k Family m68*-apollo*-sysv*,
4779 m68*-hp-bsd*, m68*-hp-hpux*
4780 Argonaut Risc Chip (ARC) arc-*-*
4781 Mitsubishi D30V d30v-*-*
4782 Fujitsu FR30 fr30-*-elf*
4783 OS/9000 i[34]86-*-os9k
4784 I960 with MON960 i960-*-coff
4786 * MIPS $fp behavior changed
4788 The convenience variable $fp, for the MIPS, now consistently returns
4789 the address of the current frame's base. Previously, depending on the
4790 context, $fp could refer to either $sp or the current frame's base
4791 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4792 The GNU Source-Level Debugger''.
4794 *** Changes in GDB 5.3:
4796 * GNU/Linux shared library multi-threaded performance improved.
4798 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4799 `/proc', in preference to `ptrace' for memory reads. This may result
4800 in an improvement in the start-up time of multi-threaded, shared
4801 library applications when run under GDB. One GDB user writes: ``loads
4802 shared libs like mad''.
4804 * ``gdbserver'' now supports multi-threaded applications on some targets
4806 Support for debugging multi-threaded applications which use
4807 the GNU/Linux LinuxThreads package has been added for
4808 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4809 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4811 * GDB now supports C/C++ preprocessor macros.
4813 GDB now expands preprocessor macro invocations in C/C++ expressions,
4814 and provides various commands for showing macro definitions and how
4817 The new command `macro expand EXPRESSION' expands any macro
4818 invocations in expression, and shows the result.
4820 The new command `show macro MACRO-NAME' shows the definition of the
4821 macro named MACRO-NAME, and where it was defined.
4823 Most compilers don't include information about macros in the debugging
4824 information by default. In GCC 3.1, for example, you need to compile
4825 your program with the options `-gdwarf-2 -g3'. If the macro
4826 information is present in the executable, GDB will read it.
4828 * Multi-arched targets.
4830 DEC Alpha (partial) alpha*-*-*
4831 DEC VAX (partial) vax-*-*
4833 National Semiconductor NS32000 (partial) ns32k-*-*
4834 Motorola 68000 (partial) m68k-*-*
4835 Motorola MCORE mcore-*-*
4839 Fujitsu FRV architecture added by Red Hat frv*-*-*
4842 * New native configurations
4844 Alpha NetBSD alpha*-*-netbsd*
4845 SH NetBSD sh*-*-netbsdelf*
4846 MIPS NetBSD mips*-*-netbsd*
4847 UltraSPARC NetBSD sparc64-*-netbsd*
4849 * OBSOLETE configurations and files
4851 Configurations that have been declared obsolete in this release have
4852 been commented out. Unless there is activity to revive these
4853 configurations, the next release of GDB will have their sources
4854 permanently REMOVED.
4856 Mitsubishi D30V d30v-*-*
4857 OS/9000 i[34]86-*-os9k
4858 IBM AIX PS/2 i[3456]86-*-aix
4859 Fujitsu FR30 fr30-*-elf*
4860 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4861 Argonaut Risc Chip (ARC) arc-*-*
4862 i386 running Mach 3.0 i[3456]86-*-mach3*
4863 i386 running Mach i[3456]86-*-mach*
4864 i386 running OSF/1 i[3456]86-*osf1mk*
4865 HP/Apollo 68k Family m68*-apollo*-sysv*,
4867 m68*-hp-bsd*, m68*-hp-hpux*
4868 I960 with MON960 i960-*-coff
4870 * OBSOLETE languages
4872 CHILL, a Pascal like language used by telecommunications companies.
4874 * REMOVED configurations and files
4876 AMD 29k family via UDI a29k-amd-udi, udi29k
4877 A29K VxWorks a29k-*-vxworks
4878 AMD 29000 embedded, using EBMON a29k-none-none
4879 AMD 29000 embedded with COFF a29k-none-coff
4880 AMD 29000 embedded with a.out a29k-none-aout
4882 testsuite/gdb.hp/gdb.threads-hp/ directory
4884 * New command "set max-user-call-depth <nnn>"
4886 This command allows the user to limit the call depth of user-defined
4887 commands. The default is 1024.
4889 * Changes in FreeBSD/i386 native debugging.
4891 Support for the "generate-core-file" has been added.
4893 * New commands "dump", "append", and "restore".
4895 These commands allow data to be copied from target memory
4896 to a bfd-format or binary file (dump and append), and back
4897 from a file into memory (restore).
4899 * Improved "next/step" support on multi-processor Alpha Tru64.
4901 The previous single-step mechanism could cause unpredictable problems,
4902 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4903 of a software single-step mechanism prevents this.
4905 *** Changes in GDB 5.2.1:
4913 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4914 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4915 Fix, by Joel Brobecker imported from mainline.
4917 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4918 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4919 Fix, by Fred Fish, imported from mainline.
4921 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4922 Surprisingly enough, it works now.
4923 By Michal Ludvig, imported from mainline.
4925 i386 hardware watchpoint support:
4926 avoid misses on second run for some targets.
4927 By Pierre Muller, imported from mainline.
4929 *** Changes in GDB 5.2:
4931 * New command "set trust-readonly-sections on[off]".
4933 This command is a hint that tells gdb that read-only sections
4934 really are read-only (ie. that their contents will not change).
4935 In this mode, gdb will go to the object file rather than the
4936 target to read memory from read-only sections (such as ".text").
4937 This can be a significant performance improvement on some
4938 (notably embedded) targets.
4940 * New command "generate-core-file" (or "gcore").
4942 This new gdb command allows the user to drop a core file of the child
4943 process state at any time. So far it's been implemented only for
4944 GNU/Linux and Solaris, but should be relatively easily ported to other
4945 hosts. Argument is core file name (defaults to core.<pid>).
4947 * New command line option
4949 GDB now accepts --pid or -p followed by a process id.
4951 * Change in command line behavior -- corefiles vs. process ids.
4953 There is a subtle behavior in the way in which GDB handles
4954 command line arguments. The first non-flag argument is always
4955 a program to debug, but the second non-flag argument may either
4956 be a corefile or a process id. Previously, GDB would attempt to
4957 open the second argument as a corefile, and if that failed, would
4958 issue a superfluous error message and then attempt to attach it as
4959 a process. Now, if the second argument begins with a non-digit,
4960 it will be treated as a corefile. If it begins with a digit,
4961 GDB will attempt to attach it as a process, and if no such process
4962 is found, will then attempt to open it as a corefile.
4964 * Changes in ARM configurations.
4966 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4967 configuration is fully multi-arch.
4969 * New native configurations
4971 ARM NetBSD arm*-*-netbsd*
4972 x86 OpenBSD i[3456]86-*-openbsd*
4973 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4974 Sparc64 running FreeBSD sparc64-*-freebsd*
4978 Sanyo XStormy16 xstormy16-elf
4980 * OBSOLETE configurations and files
4982 Configurations that have been declared obsolete in this release have
4983 been commented out. Unless there is activity to revive these
4984 configurations, the next release of GDB will have their sources
4985 permanently REMOVED.
4987 AMD 29k family via UDI a29k-amd-udi, udi29k
4988 A29K VxWorks a29k-*-vxworks
4989 AMD 29000 embedded, using EBMON a29k-none-none
4990 AMD 29000 embedded with COFF a29k-none-coff
4991 AMD 29000 embedded with a.out a29k-none-aout
4993 testsuite/gdb.hp/gdb.threads-hp/ directory
4995 * REMOVED configurations and files
4997 TI TMS320C80 tic80-*-*
4999 PowerPC Solaris powerpcle-*-solaris*
5000 PowerPC Windows NT powerpcle-*-cygwin32
5001 PowerPC Netware powerpc-*-netware*
5002 Harris/CXUX m88k m88*-harris-cxux*
5003 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5004 ns32k-utek-sysv* ns32k-utek-*
5005 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5006 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5007 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5008 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5009 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5011 * Changes to command line processing
5013 The new `--args' feature can be used to specify command-line arguments
5014 for the inferior from gdb's command line.
5016 * Changes to key bindings
5018 There is a new `operate-and-get-next' function bound to `C-o'.
5020 *** Changes in GDB 5.1.1
5022 Fix compile problem on DJGPP.
5024 Fix a problem with floating-point registers on the i386 being
5027 Fix to stop GDB crashing on .debug_str debug info.
5029 Numerous documentation fixes.
5031 Numerous testsuite fixes.
5033 *** Changes in GDB 5.1:
5035 * New native configurations
5037 Alpha FreeBSD alpha*-*-freebsd*
5038 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5039 MIPS GNU/Linux mips*-*-linux*
5040 MIPS SGI Irix 6.x mips*-sgi-irix6*
5041 ia64 AIX ia64-*-aix*
5042 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5046 Motorola 68HC11 and 68HC12 m68hc11-elf
5048 UltraSparc running GNU/Linux sparc64-*-linux*
5050 * OBSOLETE configurations and files
5052 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5053 Harris/CXUX m88k m88*-harris-cxux*
5054 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5055 ns32k-utek-sysv* ns32k-utek-*
5056 TI TMS320C80 tic80-*-*
5058 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5059 PowerPC Solaris powerpcle-*-solaris*
5060 PowerPC Windows NT powerpcle-*-cygwin32
5061 PowerPC Netware powerpc-*-netware*
5062 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5063 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5064 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5065 Apple Macintosh (MPW) host N/A
5067 stuff.c (Program to stuff files into a specially prepared space in kdb)
5068 kdb-start.c (Main loop for the standalone kernel debugger)
5070 Configurations that have been declared obsolete in this release have
5071 been commented out. Unless there is activity to revive these
5072 configurations, the next release of GDB will have their sources
5073 permanently REMOVED.
5075 * REMOVED configurations and files
5077 Altos 3068 m68*-altos-*
5078 Convex c1-*-*, c2-*-*
5080 ARM RISCix arm-*-* (as host)
5084 * GDB has been converted to ISO C.
5086 GDB's source code has been converted to ISO C. In particular, the
5087 sources are fully protoized, and rely on standard headers being
5092 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5094 * The MI enabled by default.
5096 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5097 revised and enabled by default. Packages which use GDB as a debugging
5098 engine behind a UI or another front end are encouraged to switch to
5099 using the GDB/MI interface, instead of the old annotations interface
5100 which is now deprecated.
5102 * Support for debugging Pascal programs.
5104 GDB now includes support for debugging Pascal programs. The following
5105 main features are supported:
5107 - Pascal-specific data types such as sets;
5109 - automatic recognition of Pascal sources based on file-name
5112 - Pascal-style display of data types, variables, and functions;
5114 - a Pascal expression parser.
5116 However, some important features are not yet supported.
5118 - Pascal string operations are not supported at all;
5120 - there are some problems with boolean types;
5122 - Pascal type hexadecimal constants are not supported
5123 because they conflict with the internal variables format;
5125 - support for Pascal objects and classes is not full yet;
5127 - unlike Pascal, GDB is case-sensitive for symbol names.
5129 * Changes in completion.
5131 Commands such as `shell', `run' and `set args', which pass arguments
5132 to inferior programs, now complete on file names, similar to what
5133 users expect at the shell prompt.
5135 Commands which accept locations, such as `disassemble', `print',
5136 `breakpoint', `until', etc. now complete on filenames as well as
5137 program symbols. Thus, if you type "break foob TAB", and the source
5138 files linked into the programs include `foobar.c', that file name will
5139 be one of the candidates for completion. However, file names are not
5140 considered for completion after you typed a colon that delimits a file
5141 name from a name of a function in that file, as in "break foo.c:bar".
5143 `set demangle-style' completes on available demangling styles.
5145 * New platform-independent commands:
5147 It is now possible to define a post-hook for a command as well as a
5148 hook that runs before the command. For more details, see the
5149 documentation of `hookpost' in the GDB manual.
5151 * Changes in GNU/Linux native debugging.
5153 Support for debugging multi-threaded programs has been completely
5154 revised for all platforms except m68k and sparc. You can now debug as
5155 many threads as your system allows you to have.
5157 Attach/detach is supported for multi-threaded programs.
5159 Support for SSE registers was added for x86. This doesn't work for
5160 multi-threaded programs though.
5162 * Changes in MIPS configurations.
5164 Multi-arch support is enabled for all MIPS configurations.
5166 GDB can now be built as native debugger on SGI Irix 6.x systems for
5167 debugging n32 executables. (Debugging 64-bit executables is not yet
5170 * Unified support for hardware watchpoints in all x86 configurations.
5172 Most (if not all) native x86 configurations support hardware-assisted
5173 breakpoints and watchpoints in a unified manner. This support
5174 implements debug register sharing between watchpoints, which allows to
5175 put a virtually infinite number of watchpoints on the same address,
5176 and also supports watching regions up to 16 bytes with several debug
5179 The new maintenance command `maintenance show-debug-regs' toggles
5180 debugging print-outs in functions that insert, remove, and test
5181 watchpoints and hardware breakpoints.
5183 * Changes in the DJGPP native configuration.
5185 New command ``info dos sysinfo'' displays assorted information about
5186 the CPU, OS, memory, and DPMI server.
5188 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5189 display information about segment descriptors stored in GDT, LDT, and
5192 New commands ``info dos pde'' and ``info dos pte'' display entries
5193 from Page Directory and Page Tables (for now works with CWSDPMI only).
5194 New command ``info dos address-pte'' displays the Page Table entry for
5195 a given linear address.
5197 GDB can now pass command lines longer than 126 characters to the
5198 program being debugged (requires an update to the libdbg.a library
5199 which is part of the DJGPP development kit).
5201 DWARF2 debug info is now supported.
5203 It is now possible to `step' and `next' through calls to `longjmp'.
5205 * Changes in documentation.
5207 All GDB documentation was converted to GFDL, the GNU Free
5208 Documentation License.
5210 Tracepoints-related commands are now fully documented in the GDB
5213 TUI, the Text-mode User Interface, is now documented in the manual.
5215 Tracepoints-related commands are now fully documented in the GDB
5218 The "GDB Internals" manual now has an index. It also includes
5219 documentation of `ui_out' functions, GDB coding standards, x86
5220 hardware watchpoints, and memory region attributes.
5222 * GDB's version number moved to ``version.in''
5224 The Makefile variable VERSION has been replaced by the file
5225 ``version.in''. People creating GDB distributions should update the
5226 contents of this file.
5230 GUD support is now a standard part of the EMACS distribution.
5232 *** Changes in GDB 5.0:
5234 * Improved support for debugging FP programs on x86 targets
5236 Unified and much-improved support for debugging floating-point
5237 programs on all x86 targets. In particular, ``info float'' now
5238 displays the FP registers in the same format on all x86 targets, with
5239 greater level of detail.
5241 * Improvements and bugfixes in hardware-assisted watchpoints
5243 It is now possible to watch array elements, struct members, and
5244 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5245 on x86 targets no longer erroneously trigger when the address is
5248 * Improvements in the native DJGPP version of GDB
5250 The distribution now includes all the scripts and auxiliary files
5251 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5252 machines ``out of the box''.
5254 The DJGPP version can now debug programs that use signals. It is
5255 possible to catch signals that happened in the debuggee, deliver
5256 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5257 would kill the program being debugged.) Programs that hook hardware
5258 interrupts (keyboard, timer, etc.) can also be debugged.
5260 It is now possible to debug DJGPP programs that redirect their
5261 standard handles or switch them to raw (as opposed to cooked) mode, or
5262 even close them. The command ``run < foo > bar'' works as expected,
5263 and ``info terminal'' reports useful information about the debuggee's
5264 terminal, including raw/cooked mode, redirection, etc.
5266 The DJGPP version now uses termios functions for console I/O, which
5267 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5270 DOS-style file names with drive letters are now fully supported by
5273 It is now possible to debug DJGPP programs that switch their working
5274 directory. It is also possible to rerun the debuggee any number of
5275 times without restarting GDB; thus, you can use the same setup,
5276 breakpoints, etc. for many debugging sessions.
5278 * New native configurations
5280 ARM GNU/Linux arm*-*-linux*
5281 PowerPC GNU/Linux powerpc-*-linux*
5285 Motorola MCore mcore-*-*
5286 x86 VxWorks i[3456]86-*-vxworks*
5287 PowerPC VxWorks powerpc-*-vxworks*
5288 TI TMS320C80 tic80-*-*
5290 * OBSOLETE configurations
5292 Altos 3068 m68*-altos-*
5293 Convex c1-*-*, c2-*-*
5295 ARM RISCix arm-*-* (as host)
5298 Configurations that have been declared obsolete will be commented out,
5299 but the code will be left in place. If there is no activity to revive
5300 these configurations before the next release of GDB, the sources will
5301 be permanently REMOVED.
5303 * Gould support removed
5305 Support for the Gould PowerNode and NP1 has been removed.
5307 * New features for SVR4
5309 On SVR4 native platforms (such as Solaris), if you attach to a process
5310 without first loading a symbol file, GDB will now attempt to locate and
5311 load symbols from the running process's executable file.
5313 * Many C++ enhancements
5315 C++ support has been greatly improved. Overload resolution now works properly
5316 in almost all cases. RTTI support is on the way.
5318 * Remote targets can connect to a sub-program
5320 A popen(3) style serial-device has been added. This device starts a
5321 sub-process (such as a stand-alone simulator) and then communicates
5322 with that. The sub-program to run is specified using the syntax
5323 ``|<program> <args>'' vis:
5325 (gdb) set remotedebug 1
5326 (gdb) target extended-remote |mn10300-elf-sim program-args
5328 * MIPS 64 remote protocol
5330 A long standing bug in the mips64 remote protocol where by GDB
5331 expected certain 32 bit registers (ex SR) to be transfered as 32
5332 instead of 64 bits has been fixed.
5334 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5335 added to provide backward compatibility with older versions of GDB.
5337 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5339 The command ``set remotebinarydownload'' command has been replaced by
5340 ``set remote X-packet''. Other commands in ``set remote'' family
5341 include ``set remote P-packet''.
5343 * Breakpoint commands accept ranges.
5345 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5346 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5347 ``tracepoint passcount'' also accepts a range of tracepoints.
5349 * ``apropos'' command added.
5351 The ``apropos'' command searches through command names and
5352 documentation strings, printing out matches, making it much easier to
5353 try to find a command that does what you are looking for.
5357 A new machine oriented interface (MI) has been added to GDB. This
5358 interface is designed for debug environments running GDB as a separate
5359 process. This is part of the long term libGDB project. See the
5360 "GDB/MI" chapter of the GDB manual for further information. It can be
5361 enabled by configuring with:
5363 .../configure --enable-gdbmi
5365 *** Changes in GDB-4.18:
5367 * New native configurations
5369 HP-UX 10.20 hppa*-*-hpux10.20
5370 HP-UX 11.x hppa*-*-hpux11.0*
5371 M68K GNU/Linux m68*-*-linux*
5375 Fujitsu FR30 fr30-*-elf*
5376 Intel StrongARM strongarm-*-*
5377 Mitsubishi D30V d30v-*-*
5379 * OBSOLETE configurations
5381 Gould PowerNode, NP1 np1-*-*, pn-*-*
5383 Configurations that have been declared obsolete will be commented out,
5384 but the code will be left in place. If there is no activity to revive
5385 these configurations before the next release of GDB, the sources will
5386 be permanently REMOVED.
5390 As a compatibility experiment, GDB's source files buildsym.h and
5391 buildsym.c have been converted to pure standard C, no longer
5392 containing any K&R compatibility code. We believe that all systems in
5393 use today either come with a standard C compiler, or have a GCC port
5394 available. If this is not true, please report the affected
5395 configuration to bug-gdb@gnu.org immediately. See the README file for
5396 information about getting a standard C compiler if you don't have one
5401 GDB now uses readline 2.2.
5403 * set extension-language
5405 You can now control the mapping between filename extensions and source
5406 languages by using the `set extension-language' command. For instance,
5407 you can ask GDB to treat .c files as C++ by saying
5408 set extension-language .c c++
5409 The command `info extensions' lists all of the recognized extensions
5410 and their associated languages.
5412 * Setting processor type for PowerPC and RS/6000
5414 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5415 you can use the `set processor' command to specify what variant of the
5416 PowerPC family you are debugging. The command
5420 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5421 following PowerPC and RS6000 variants:
5423 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5424 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5426 403GC IBM PowerPC 403GC
5427 505 Motorola PowerPC 505
5428 860 Motorola PowerPC 860 or 850
5429 601 Motorola PowerPC 601
5430 602 Motorola PowerPC 602
5431 603 Motorola/IBM PowerPC 603 or 603e
5432 604 Motorola PowerPC 604 or 604e
5433 750 Motorola/IBM PowerPC 750 or 750
5435 At the moment, this command just tells GDB what to name the
5436 special-purpose processor registers. Since almost all the affected
5437 registers are inaccessible to user-level programs, this command is
5438 only useful for remote debugging in its present form.
5442 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5443 more extensive support for HP-UX. Added features include shared
5444 library support, kernel threads and hardware watchpoints for 11.00,
5445 support for HP's ANSI C and C++ compilers, and a compatibility mode
5446 for xdb and dbx commands.
5450 HP's donation includes the new concept of catchpoints, which is a
5451 generalization of the old catch command. On HP-UX, it is now possible
5452 to catch exec, fork, and vfork, as well as library loading.
5454 This means that the existing catch command has changed; its first
5455 argument now specifies the type of catch to be set up. See the
5456 output of "help catch" for a list of catchpoint types.
5458 * Debugging across forks
5460 On HP-UX, you can choose which process to debug when a fork() happens
5465 HP has donated a curses-based terminal user interface (TUI). To get
5466 it, build with --enable-tui. Although this can be enabled for any
5467 configuration, at present it only works for native HP debugging.
5469 * GDB remote protocol additions
5471 A new protocol packet 'X' that writes binary data is now available.
5472 Default behavior is to try 'X', then drop back to 'M' if the stub
5473 fails to respond. The settable variable `remotebinarydownload'
5474 allows explicit control over the use of 'X'.
5476 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5477 full 64-bit address. The command
5479 set remoteaddresssize 32
5481 can be used to revert to the old behaviour. For existing remote stubs
5482 the change should not be noticed, as the additional address information
5485 In order to assist in debugging stubs, you may use the maintenance
5486 command `packet' to send any text string to the stub. For instance,
5488 maint packet heythere
5490 sends the packet "$heythere#<checksum>". Note that it is very easy to
5491 disrupt a debugging session by sending the wrong packet at the wrong
5494 The compare-sections command allows you to compare section data on the
5495 target to what is in the executable file without uploading or
5496 downloading, by comparing CRC checksums.
5498 * Tracing can collect general expressions
5500 You may now collect general expressions at tracepoints. This requires
5501 further additions to the target-side stub; see tracepoint.c and
5502 doc/agentexpr.texi for further details.
5504 * mask-address variable for Mips
5506 For Mips targets, you may control the zeroing of the upper 32 bits of
5507 a 64-bit address by entering `set mask-address on'. This is mainly
5508 of interest to users of embedded R4xxx and R5xxx processors.
5510 * Higher serial baud rates
5512 GDB's serial code now allows you to specify baud rates 57600, 115200,
5513 230400, and 460800 baud. (Note that your host system may not be able
5514 to achieve all of these rates.)
5518 The i960 configuration now includes an initial implementation of a
5519 builtin simulator, contributed by Jim Wilson.
5522 *** Changes in GDB-4.17:
5524 * New native configurations
5526 Alpha GNU/Linux alpha*-*-linux*
5527 Unixware 2.x i[3456]86-unixware2*
5528 Irix 6.x mips*-sgi-irix6*
5529 PowerPC GNU/Linux powerpc-*-linux*
5530 PowerPC Solaris powerpcle-*-solaris*
5531 Sparc GNU/Linux sparc-*-linux*
5532 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5536 Argonaut Risc Chip (ARC) arc-*-*
5537 Hitachi H8/300S h8300*-*-*
5538 Matsushita MN10200 w/simulator mn10200-*-*
5539 Matsushita MN10300 w/simulator mn10300-*-*
5540 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5541 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5542 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5543 Mitsubishi D10V w/simulator d10v-*-*
5544 Mitsubishi M32R/D w/simulator m32r-*-elf*
5545 Tsqware Sparclet sparclet-*-*
5546 NEC V850 w/simulator v850-*-*
5548 * New debugging protocols
5550 ARM with RDI protocol arm*-*-*
5551 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5552 DDB and LSI variants of PMON protocol mips*-*-*
5553 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5554 PowerPC with SDS protocol powerpc{,le}-*-eabi
5555 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5559 All configurations can now understand and use the DWARF 2 debugging
5560 format. The choice is automatic, if the symbol file contains DWARF 2
5565 GDB now includes basic Java language support. This support is
5566 only useful with Java compilers that produce native machine code.
5568 * solib-absolute-prefix and solib-search-path
5570 For SunOS and SVR4 shared libraries, you may now set the prefix for
5571 loading absolute shared library symbol files, and the search path for
5572 locating non-absolute shared library symbol files.
5574 * Live range splitting
5576 GDB can now effectively debug code for which GCC has performed live
5577 range splitting as part of its optimization. See gdb/doc/LRS for
5578 more details on the expected format of the stabs information.
5582 GDB's support for the GNU Hurd, including thread debugging, has been
5583 updated to work with current versions of the Hurd.
5587 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5588 instruction set. ARM GDB automatically detects when Thumb
5589 instructions are in use, and adjusts disassembly and backtracing
5594 GDB's MIPS target configurations now handle the MIP16 16-bit
5599 GDB now includes support for overlays; if an executable has been
5600 linked such that multiple sections are based at the same address, GDB
5601 will decide which section to use for symbolic info. You can choose to
5602 control the decision manually, using overlay commands, or implement
5603 additional target-side support and use "overlay load-target" to bring
5604 in the overlay mapping. Do "help overlay" for more detail.
5608 The command "info symbol <address>" displays information about
5609 the symbol at the specified address.
5613 The standard remote protocol now includes an extension that allows
5614 asynchronous collection and display of trace data. This requires
5615 extensive support in the target-side debugging stub. Tracing mode
5616 includes a new interaction mode in GDB and new commands: see the
5617 file tracepoint.c for more details.
5621 Configurations for embedded MIPS now include a simulator contributed
5622 by Cygnus Solutions. The simulator supports the instruction sets
5623 of most MIPS variants.
5627 Sparc configurations may now include the ERC32 simulator contributed
5628 by the European Space Agency. The simulator is not built into
5629 Sparc targets by default; configure with --enable-sim to include it.
5633 For target configurations that may include multiple variants of a
5634 basic architecture (such as MIPS and SH), you may now set the
5635 architecture explicitly. "set arch" sets, "info arch" lists
5636 the possible architectures.
5638 *** Changes in GDB-4.16:
5640 * New native configurations
5642 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5643 M68K NetBSD m68k-*-netbsd*
5644 PowerPC AIX 4.x powerpc-*-aix*
5645 PowerPC MacOS powerpc-*-macos*
5646 PowerPC Windows NT powerpcle-*-cygwin32
5647 RS/6000 AIX 4.x rs6000-*-aix4*
5651 ARM with RDP protocol arm-*-*
5652 I960 with MON960 i960-*-coff
5653 MIPS VxWorks mips*-*-vxworks*
5654 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5655 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5657 Matra Sparclet sparclet-*-*
5661 The powerpc-eabi configuration now includes the PSIM simulator,
5662 contributed by Andrew Cagney, with assistance from Mike Meissner.
5663 PSIM is a very elaborate model of the PowerPC, including not only
5664 basic instruction set execution, but also details of execution unit
5665 performance and I/O hardware. See sim/ppc/README for more details.
5669 GDB now works with Solaris 2.5.
5671 * Windows 95/NT native
5673 GDB will now work as a native debugger on Windows 95 and Windows NT.
5674 To build it from source, you must use the "gnu-win32" environment,
5675 which uses a DLL to emulate enough of Unix to run the GNU tools.
5676 Further information, binaries, and sources are available at
5677 ftp.cygnus.com, under pub/gnu-win32.
5679 * dont-repeat command
5681 If a user-defined command includes the command `dont-repeat', then the
5682 command will not be repeated if the user just types return. This is
5683 useful if the command is time-consuming to run, so that accidental
5684 extra keystrokes don't run the same command many times.
5686 * Send break instead of ^C
5688 The standard remote protocol now includes an option to send a break
5689 rather than a ^C to the target in order to interrupt it. By default,
5690 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5692 * Remote protocol timeout
5694 The standard remote protocol includes a new variable `remotetimeout'
5695 that allows you to set the number of seconds before GDB gives up trying
5696 to read from the target. The default value is 2.
5698 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5700 By default GDB will automatically keep track of objects as they are
5701 loaded and unloaded by the dynamic linker. By using the command `set
5702 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5703 when shared library events occur, thus allowing you to set breakpoints
5704 in shared libraries which are explicitly loaded by the inferior.
5706 Note this feature does not work on hpux8. On hpux9 you must link
5707 /usr/lib/end.o into your program. This feature should work
5708 automatically on hpux10.
5710 * Irix 5.x hardware watchpoint support
5712 Irix 5 configurations now support the use of hardware watchpoints.
5714 * Mips protocol "SYN garbage limit"
5716 When debugging a Mips target using the `target mips' protocol, you
5717 may set the number of characters that GDB will ignore by setting
5718 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5719 every character. The default value is 1050.
5721 * Recording and replaying remote debug sessions
5723 If you set `remotelogfile' to the name of a file, gdb will write to it
5724 a recording of a remote debug session. This recording may then be
5725 replayed back to gdb using "gdbreplay". See gdbserver/README for
5726 details. This is useful when you have a problem with GDB while doing
5727 remote debugging; you can make a recording of the session and send it
5728 to someone else, who can then recreate the problem.
5730 * Speedups for remote debugging
5732 GDB includes speedups for downloading and stepping MIPS systems using
5733 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5734 and more efficient S-record downloading.
5736 * Memory use reductions and statistics collection
5738 GDB now uses less memory and reports statistics about memory usage.
5739 Try the `maint print statistics' command, for example.
5741 *** Changes in GDB-4.15:
5743 * Psymtabs for XCOFF
5745 The symbol reader for AIX GDB now uses partial symbol tables. This
5746 can greatly improve startup time, especially for large executables.
5748 * Remote targets use caching
5750 Remote targets now use a data cache to speed up communication with the
5751 remote side. The data cache could lead to incorrect results because
5752 it doesn't know about volatile variables, thus making it impossible to
5753 debug targets which use memory mapped I/O devices. `set remotecache
5754 off' turns the the data cache off.
5756 * Remote targets may have threads
5758 The standard remote protocol now includes support for multiple threads
5759 in the target system, using new protocol commands 'H' and 'T'. See
5760 gdb/remote.c for details.
5764 If GDB is configured with `--enable-netrom', then it will include
5765 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5766 acts as though it is a bank of ROM on the target board, but you can
5767 write into it over the network. GDB's support consists only of
5768 support for fast loading into the emulated ROM; to debug, you must use
5769 another protocol, such as standard remote protocol. The usual
5770 sequence is something like
5772 target nrom <netrom-hostname>
5774 target remote <netrom-hostname>:1235
5778 GDB now includes support for the Apple Macintosh, as a host only. It
5779 may be run as either an MPW tool or as a standalone application, and
5780 it can debug through the serial port. All the usual GDB commands are
5781 available, but to the target command, you must supply "serial" as the
5782 device type instead of "/dev/ttyXX". See mpw-README in the main
5783 directory for more information on how to build. The MPW configuration
5784 scripts */mpw-config.in support only a few targets, and only the
5785 mips-idt-ecoff target has been tested.
5789 GDB configuration now uses autoconf. This is not user-visible,
5790 but does simplify configuration and building.
5794 GDB now supports hpux10.
5796 *** Changes in GDB-4.14:
5798 * New native configurations
5800 x86 FreeBSD i[345]86-*-freebsd
5801 x86 NetBSD i[345]86-*-netbsd
5802 NS32k NetBSD ns32k-*-netbsd
5803 Sparc NetBSD sparc-*-netbsd
5807 A29K VxWorks a29k-*-vxworks
5808 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5809 CPU32 EST-300 emulator m68*-*-est*
5810 PowerPC ELF powerpc-*-elf
5813 * Alpha OSF/1 support for procfs
5815 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5816 possible to attach to running processes. As the mounting of the /proc
5817 filesystem is optional on the Alpha, GDB automatically determines
5818 the availability of /proc during startup. This can lead to problems
5819 if /proc is unmounted after GDB has been started.
5821 * Arguments to user-defined commands
5823 User commands may accept up to 10 arguments separated by whitespace.
5824 Arguments are accessed within the user command via $arg0..$arg9. A
5827 print $arg0 + $arg1 + $arg2
5829 To execute the command use:
5832 Defines the command "adder" which prints the sum of its three arguments.
5833 Note the arguments are text substitutions, so they may reference variables,
5834 use complex expressions, or even perform inferior function calls.
5836 * New `if' and `while' commands
5838 This makes it possible to write more sophisticated user-defined
5839 commands. Both commands take a single argument, which is the
5840 expression to evaluate, and must be followed by the commands to
5841 execute, one per line, if the expression is nonzero, the list being
5842 terminated by the word `end'. The `if' command list may include an
5843 `else' word, which causes the following commands to be executed only
5844 if the expression is zero.
5846 * Fortran source language mode
5848 GDB now includes partial support for Fortran 77. It will recognize
5849 Fortran programs and can evaluate a subset of Fortran expressions, but
5850 variables and functions may not be handled correctly. GDB will work
5851 with G77, but does not yet know much about symbols emitted by other
5854 * Better HPUX support
5856 Most debugging facilities now work on dynamic executables for HPPAs
5857 running hpux9 or later. You can attach to running dynamically linked
5858 processes, but by default the dynamic libraries will be read-only, so
5859 for instance you won't be able to put breakpoints in them. To change
5860 that behavior do the following before running the program:
5866 This will cause the libraries to be mapped private and read-write.
5867 To revert to the normal behavior, do this:
5873 You cannot set breakpoints or examine data in the library until after
5874 the library is loaded if the function/data symbols do not have
5877 GDB can now also read debug symbols produced by the HP C compiler on
5878 HPPAs (sorry, no C++, Fortran or 68k support).
5880 * Target byte order now dynamically selectable
5882 You can choose which byte order to use with a target system, via the
5883 commands "set endian big" and "set endian little", and you can see the
5884 current setting by using "show endian". You can also give the command
5885 "set endian auto", in which case GDB will use the byte order
5886 associated with the executable. Currently, only embedded MIPS
5887 configurations support dynamic selection of target byte order.
5889 * New DOS host serial code
5891 This version uses DPMI interrupts to handle buffered I/O, so you
5892 no longer need to run asynctsr when debugging boards connected to
5895 *** Changes in GDB-4.13:
5897 * New "complete" command
5899 This lists all the possible completions for the rest of the line, if it
5900 were to be given as a command itself. This is intended for use by emacs.
5902 * Trailing space optional in prompt
5904 "set prompt" no longer adds a space for you after the prompt you set. This
5905 allows you to set a prompt which ends in a space or one that does not.
5907 * Breakpoint hit counts
5909 "info break" now displays a count of the number of times the breakpoint
5910 has been hit. This is especially useful in conjunction with "ignore"; you
5911 can ignore a large number of breakpoint hits, look at the breakpoint info
5912 to see how many times the breakpoint was hit, then run again, ignoring one
5913 less than that number, and this will get you quickly to the last hit of
5916 * Ability to stop printing at NULL character
5918 "set print null-stop" will cause GDB to stop printing the characters of
5919 an array when the first NULL is encountered. This is useful when large
5920 arrays actually contain only short strings.
5922 * Shared library breakpoints
5924 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5925 breakpoints in shared libraries before the executable is run.
5927 * Hardware watchpoints
5929 There is a new hardware breakpoint for the watch command for sparclite
5930 targets. See gdb/sparclite/hw_breakpoint.note.
5932 Hardware watchpoints are also now supported under GNU/Linux.
5936 Annotations have been added. These are for use with graphical interfaces,
5937 and are still experimental. Currently only gdba.el uses these.
5939 * Improved Irix 5 support
5941 GDB now works properly with Irix 5.2.
5943 * Improved HPPA support
5945 GDB now works properly with the latest GCC and GAS.
5947 * New native configurations
5949 Sequent PTX4 i[34]86-sequent-ptx4
5950 HPPA running OSF/1 hppa*-*-osf*
5951 Atari TT running SVR4 m68*-*-sysv4*
5952 RS/6000 LynxOS rs6000-*-lynxos*
5956 OS/9000 i[34]86-*-os9k
5957 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5960 * Hitachi SH7000 and E7000-PC ICE support
5962 There is now support for communicating with the Hitachi E7000-PC ICE.
5963 This is available automatically when GDB is configured for the SH.
5967 As usual, a variety of small fixes and improvements, both generic
5968 and configuration-specific. See the ChangeLog for more detail.
5970 *** Changes in GDB-4.12:
5972 * Irix 5 is now supported
5976 GDB-4.12 on the HPPA has a number of changes which make it unable
5977 to debug the output from the currently released versions of GCC and
5978 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5979 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5980 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5983 *** Changes in GDB-4.11:
5985 * User visible changes:
5989 The "set remotedebug" option is now consistent between the mips remote
5990 target, remote targets using the gdb-specific protocol, UDI (AMD's
5991 debug protocol for the 29k) and the 88k bug monitor. It is now an
5992 integer specifying a debug level (normally 0 or 1, but 2 means more
5993 debugging info for the mips target).
5995 * DEC Alpha native support
5997 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5998 debug info, but GDB works fairly well with the DEC compiler and should
5999 work with a future GCC release. See the README file for a few
6000 Alpha-specific notes.
6002 * Preliminary thread implementation
6004 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6006 * LynxOS native and target support for 386
6008 This release has been hosted on LynxOS 2.2, and also can be configured
6009 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6012 * Improvements in C++ mangling/demangling.
6014 This release has much better g++ debugging, specifically in name
6015 mangling/demangling, virtual function calls, print virtual table,
6016 call methods, ...etc.
6018 *** Changes in GDB-4.10:
6020 * User visible changes:
6022 Remote debugging using the GDB-specific (`target remote') protocol now
6023 supports the `load' command. This is only useful if you have some
6024 other way of getting the stub to the target system, and you can put it
6025 somewhere in memory where it won't get clobbered by the download.
6027 Filename completion now works.
6029 When run under emacs mode, the "info line" command now causes the
6030 arrow to point to the line specified. Also, "info line" prints
6031 addresses in symbolic form (as well as hex).
6033 All vxworks based targets now support a user settable option, called
6034 vxworks-timeout. This option represents the number of seconds gdb
6035 should wait for responses to rpc's. You might want to use this if
6036 your vxworks target is, perhaps, a slow software simulator or happens
6037 to be on the far side of a thin network line.
6041 This release contains support for using a DEC alpha as a GDB host for
6042 cross debugging. Native alpha debugging is not supported yet.
6045 *** Changes in GDB-4.9:
6049 This is the first GDB release which is accompanied by a matching testsuite.
6050 The testsuite requires installation of dejagnu, which should be available
6051 via ftp from most sites that carry GNU software.
6055 'Cfront' style demangling has had its name changed to 'ARM' style, to
6056 emphasize that it was written from the specifications in the C++ Annotated
6057 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6058 disclaimers, it still generated too much confusion with users attempting to
6059 use gdb with AT&T cfront.
6063 GDB now uses a standard remote interface to a simulator library.
6064 So far, the library contains simulators for the Zilog Z8001/2, the
6065 Hitachi H8/300, H8/500 and Super-H.
6067 * New targets supported
6069 H8/300 simulator h8300-hitachi-hms or h8300hms
6070 H8/500 simulator h8500-hitachi-hms or h8500hms
6071 SH simulator sh-hitachi-hms or sh
6072 Z8000 simulator z8k-zilog-none or z8ksim
6073 IDT MIPS board over serial line mips-idt-ecoff
6075 Cross-debugging to GO32 targets is supported. It requires a custom
6076 version of the i386-stub.c module which is integrated with the
6077 GO32 memory extender.
6079 * New remote protocols
6081 MIPS remote debugging protocol.
6083 * New source languages supported
6085 This version includes preliminary support for Chill, a Pascal like language
6086 used by telecommunications companies. Chill support is also being integrated
6087 into the GNU compiler, but we don't know when it will be publically available.
6090 *** Changes in GDB-4.8:
6092 * HP Precision Architecture supported
6094 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6095 version of this support was available as a set of patches from the
6096 University of Utah. GDB does not support debugging of programs
6097 compiled with the HP compiler, because HP will not document their file
6098 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6099 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6101 Many problems in the preliminary version have been fixed.
6103 * Faster and better demangling
6105 We have improved template demangling and fixed numerous bugs in the GNU style
6106 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6107 character types (wchar_t) are now supported. Demangling of each symbol is now
6108 only done once, and is cached when the symbol table for a file is read in.
6109 This results in a small increase in memory usage for C programs, a moderate
6110 increase in memory usage for C++ programs, and a fantastic speedup in
6113 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6114 from the specifications in the Annotated Reference Manual, which AT&T's
6115 compiler does not actually implement.
6117 * G++ multiple inheritance compiler problem
6119 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6120 inheritance lattices was reworked to properly discover ambiguities. We
6121 recently found an example which causes this new algorithm to fail in a
6122 very subtle way, producing bad debug information for those classes.
6123 The file 'gcc.patch' (in this directory) can be applied to gcc to
6124 circumvent the problem. A future GCC release will contain a complete
6127 The previous G++ debug info problem (mentioned below for the gdb-4.7
6128 release) is fixed in gcc version 2.3.2.
6130 * Improved configure script
6132 The `configure' script will now attempt to guess your system type if
6133 you don't supply a host system type. The old scheme of supplying a
6134 host system triplet is preferable over using this. All the magic is
6135 done in the new `config.guess' script. Examine it for details.
6137 We have also brought our configure script much more in line with the FSF's
6138 version. It now supports the --with-xxx options. In particular,
6139 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6140 The resulting GDB will not be able to read arbitrary object file formats --
6141 only the format ``expected'' to be used on the configured target system.
6142 We hope to make this the default in a future release.
6144 * Documentation improvements
6146 There's new internal documentation on how to modify GDB, and how to
6147 produce clean changes to the code. We implore people to read it
6148 before submitting changes.
6150 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6151 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6152 `info' files are also provided. To build `info' files from scratch,
6153 you will need the latest `makeinfo' release, which will be available in
6154 a future texinfo-X.Y release.
6156 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6157 We're not sure exactly which versions have this problem, but it has
6158 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6159 or better. If that isn't possible, there is a patch in
6160 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6161 around this problem.
6165 GDB now supports array constants that can be used in expressions typed in by
6166 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6167 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6170 The new directory `gdb/sparclite' contains a program that demonstrates
6171 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6173 * New native hosts supported
6175 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6176 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6178 * New targets supported
6180 AMD 29k family via UDI a29k-amd-udi or udi29k
6182 * New file formats supported
6184 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6185 HPUX core files, and SCO 3.2v2 core files.
6189 Attaching to processes now works again; thanks for the many bug reports.
6191 We have also stomped on a bunch of core dumps caused by
6192 printf_filtered("%s") problems.
6194 We eliminated a copyright problem on the rpc and ptrace header files
6195 for VxWorks, which was discovered at the last minute during the 4.7
6196 release. You should now be able to build a VxWorks GDB.
6198 You can now interrupt gdb while an attached process is running. This
6199 will cause the attached process to stop, and give control back to GDB.
6201 We fixed problems caused by using too many file descriptors
6202 for reading symbols from object files and libraries. This was
6203 especially a problem for programs that used many (~100) shared
6206 The `step' command now only enters a subroutine if there is line number
6207 information for the subroutine. Otherwise it acts like the `next'
6208 command. Previously, `step' would enter subroutines if there was
6209 any debugging information about the routine. This avoids problems
6210 when using `cc -g1' on MIPS machines.
6212 * Internal improvements
6214 GDB's internal interfaces have been improved to make it easier to support
6215 debugging of multiple languages in the future.
6217 GDB now uses a common structure for symbol information internally.
6218 Minimal symbols (derived from linkage symbols in object files), partial
6219 symbols (from a quick scan of debug information), and full symbols
6220 contain a common subset of information, making it easier to write
6221 shared code that handles any of them.
6223 * New command line options
6225 We now accept --silent as an alias for --quiet.
6229 The memory-mapped-malloc library is now licensed under the GNU Library
6230 General Public License.
6232 *** Changes in GDB-4.7:
6234 * Host/native/target split
6236 GDB has had some major internal surgery to untangle the support for
6237 hosts and remote targets. Now, when you configure GDB for a remote
6238 target, it will no longer load in all of the support for debugging
6239 local programs on the host. When fully completed and tested, this will
6240 ensure that arbitrary host/target combinations are possible.
6242 The primary conceptual shift is to separate the non-portable code in
6243 GDB into three categories. Host specific code is required any time GDB
6244 is compiled on that host, regardless of the target. Target specific
6245 code relates to the peculiarities of the target, but can be compiled on
6246 any host. Native specific code is everything else: it can only be
6247 built when the host and target are the same system. Child process
6248 handling and core file support are two common `native' examples.
6250 GDB's use of /proc for controlling Unix child processes is now cleaner.
6251 It has been split out into a single module under the `target_ops' vector,
6252 plus two native-dependent functions for each system that uses /proc.
6254 * New hosts supported
6256 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6257 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6258 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6260 * New targets supported
6262 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6263 68030 and CPU32 m68030-*-*, m68332-*-*
6265 * New native hosts supported
6267 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6268 (386bsd is not well tested yet)
6269 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6271 * New file formats supported
6273 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6274 supports reading of `a.out.adobe' object files, which are an a.out
6275 format extended with minimal information about multiple sections.
6279 `show copying' is the same as the old `info copying'.
6280 `show warranty' is the same as `info warrantee'.
6281 These were renamed for consistency. The old commands continue to work.
6283 `info handle' is a new alias for `info signals'.
6285 You can now define pre-command hooks, which attach arbitrary command
6286 scripts to any command. The commands in the hook will be executed
6287 prior to the user's command. You can also create a hook which will be
6288 executed whenever the program stops. See gdb.texinfo.
6292 We now deal with Cfront style name mangling, and can even extract type
6293 info from mangled symbols. GDB can automatically figure out which
6294 symbol mangling style your C++ compiler uses.
6296 Calling of methods and virtual functions has been improved as well.
6300 The crash that occured when debugging Sun Ansi-C compiled binaries is
6301 fixed. This was due to mishandling of the extra N_SO stabs output
6304 We also finally got Ultrix 4.2 running in house, and fixed core file
6305 support, with help from a dozen people on the net.
6307 John M. Farrell discovered that the reason that single-stepping was so
6308 slow on all of the Mips based platforms (primarily SGI and DEC) was
6309 that we were trying to demangle and lookup a symbol used for internal
6310 purposes on every instruction that was being stepped through. Changing
6311 the name of that symbol so that it couldn't be mistaken for a C++
6312 mangled symbol sped things up a great deal.
6314 Rich Pixley sped up symbol lookups in general by getting much smarter
6315 about when C++ symbol mangling is necessary. This should make symbol
6316 completion (TAB on the command line) much faster. It's not as fast as
6317 we'd like, but it's significantly faster than gdb-4.6.
6321 A new user controllable variable 'call_scratch_address' can
6322 specify the location of a scratch area to be used when GDB
6323 calls a function in the target. This is necessary because the
6324 usual method of putting the scratch area on the stack does not work
6325 in systems that have separate instruction and data spaces.
6327 We integrated changes to support the 29k UDI (Universal Debugger
6328 Interface), but discovered at the last minute that we didn't have all
6329 of the appropriate copyright paperwork. We are working with AMD to
6330 resolve this, and hope to have it available soon.
6334 We have sped up the remote serial line protocol, especially for targets
6335 with lots of registers. It now supports a new `expedited status' ('T')
6336 message which can be used in place of the existing 'S' status message.
6337 This allows the remote stub to send only the registers that GDB
6338 needs to make a quick decision about single-stepping or conditional
6339 breakpoints, eliminating the need to fetch the entire register set for
6340 each instruction being stepped through.
6342 The GDB remote serial protocol now implements a write-through cache for
6343 registers, only re-reading the registers if the target has run.
6345 There is also a new remote serial stub for SPARC processors. You can
6346 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6347 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6348 processor with a serial port.
6352 Configure.in files have become much easier to read and modify. A new
6353 `table driven' format makes it more obvious what configurations are
6354 supported, and what files each one uses.
6358 There is a new opcodes library which will eventually contain all of the
6359 disassembly routines and opcode tables. At present, it only contains
6360 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6361 disassembler (binutils/objdump) to share these routines.
6363 The libiberty library is now copylefted under the GNU Library General
6364 Public License. This allows more liberal use, and was done so libg++
6365 can use it. This makes no difference to GDB, since the Library License
6366 grants all the rights from the General Public License.
6370 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6371 reference to the stabs symbol info used by the debugger. It is (as far
6372 as we know) the only published document on this fascinating topic. We
6373 encourage you to read it, compare it to the stabs information on your
6374 system, and send improvements on the document in general (to
6375 bug-gdb@prep.ai.mit.edu).
6377 And, of course, many bugs have been fixed.
6380 *** Changes in GDB-4.6:
6382 * Better support for C++ function names
6384 GDB now accepts as input the "demangled form" of C++ overloaded function
6385 names and member function names, and can do command completion on such names
6386 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6387 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6388 Make use of command completion, it is your friend.
6390 GDB also now accepts a variety of C++ mangled symbol formats. They are
6391 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6392 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6393 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6394 for the list of formats.
6396 * G++ symbol mangling problem
6398 Recent versions of gcc have a bug in how they emit debugging information for
6399 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6400 directory) can be applied to gcc to fix the problem. Alternatively, if you
6401 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6402 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6403 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6406 * New 'maintenance' command
6408 All of the commands related to hacking GDB internals have been moved out of
6409 the main command set, and now live behind the 'maintenance' command. This
6410 can also be abbreviated as 'mt'. The following changes were made:
6412 dump-me -> maintenance dump-me
6413 info all-breakpoints -> maintenance info breakpoints
6414 printmsyms -> maintenance print msyms
6415 printobjfiles -> maintenance print objfiles
6416 printpsyms -> maintenance print psymbols
6417 printsyms -> maintenance print symbols
6419 The following commands are new:
6421 maintenance demangle Call internal GDB demangler routine to
6422 demangle a C++ link name and prints the result.
6423 maintenance print type Print a type chain for a given symbol
6425 * Change to .gdbinit file processing
6427 We now read the $HOME/.gdbinit file before processing the argv arguments
6428 (e.g. reading symbol files or core files). This allows global parameters to
6429 be set, which will apply during the symbol reading. The ./.gdbinit is still
6430 read after argv processing.
6432 * New hosts supported
6434 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6436 GNU/Linux support i386-unknown-linux or linux
6438 We are also including code to support the HP/PA running BSD and HPUX. This
6439 is almost guaranteed not to work, as we didn't have time to test or build it
6440 for this release. We are including it so that the more adventurous (or
6441 masochistic) of you can play with it. We also had major problems with the
6442 fact that the compiler that we got from HP doesn't support the -g option.
6445 * New targets supported
6447 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6449 * More smarts about finding #include files
6451 GDB now remembers the compilation directory for all include files, and for
6452 all files from which C is generated (like yacc and lex sources). This
6453 greatly improves GDB's ability to find yacc/lex sources, and include files,
6454 especially if you are debugging your program from a directory different from
6455 the one that contains your sources.
6457 We also fixed a bug which caused difficulty with listing and setting
6458 breakpoints in include files which contain C code. (In the past, you had to
6459 try twice in order to list an include file that you hadn't looked at before.)
6461 * Interesting infernals change
6463 GDB now deals with arbitrary numbers of sections, where the symbols for each
6464 section must be relocated relative to that section's landing place in the
6465 target's address space. This work was needed to support ELF with embedded
6466 stabs used by Solaris-2.0.
6468 * Bug fixes (of course!)
6470 There have been loads of fixes for the following things:
6471 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6472 i960, stabs, DOS(GO32), procfs, etc...
6474 See the ChangeLog for details.
6476 *** Changes in GDB-4.5:
6478 * New machines supported (host and target)
6480 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6482 SGI Irix-4.x mips-sgi-irix4 or iris4
6484 * New malloc package
6486 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6487 Mmalloc is capable of handling mutiple heaps of memory. It is also
6488 capable of saving a heap to a file, and then mapping it back in later.
6489 This can be used to greatly speedup the startup of GDB by using a
6490 pre-parsed symbol table which lives in a mmalloc managed heap. For
6491 more details, please read mmalloc/mmalloc.texi.
6495 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6496 'help info proc' for details.
6498 * MIPS ecoff symbol table format
6500 The code that reads MIPS symbol table format is now supported on all hosts.
6501 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6504 * File name changes for MS-DOS
6506 Many files in the config directories have been renamed to make it easier to
6507 support GDB on MS-DOSe systems (which have very restrictive file name
6508 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6509 environment) is close to working but has some remaining problems. Note
6510 that debugging of DOS programs is not supported, due to limitations
6511 in the ``operating system'', but it can be used to host cross-debugging.
6513 * Cross byte order fixes
6515 Many fixes have been made to support cross debugging of Sparc and MIPS
6516 targets from hosts whose byte order differs.
6518 * New -mapped and -readnow options
6520 If memory-mapped files are available on your system through the 'mmap'
6521 system call, you can use the -mapped option on the `file' or
6522 `symbol-file' commands to cause GDB to write the symbols from your
6523 program into a reusable file. If the program you are debugging is
6524 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6525 Future GDB debugging sessions will notice the presence of this file,
6526 and will quickly map in symbol information from it, rather than reading
6527 the symbol table from the executable program. Using the '-mapped'
6528 option in a GDB `file' or `symbol-file' command has the same effect as
6529 starting GDB with the '-mapped' command-line option.
6531 You can cause GDB to read the entire symbol table immediately by using
6532 the '-readnow' option with any of the commands that load symbol table
6533 information (or on the GDB command line). This makes the command
6534 slower, but makes future operations faster.
6536 The -mapped and -readnow options are typically combined in order to
6537 build a `fred.syms' file that contains complete symbol information.
6538 A simple GDB invocation to do nothing but build a `.syms' file for future
6541 gdb -batch -nx -mapped -readnow programname
6543 The `.syms' file is specific to the host machine on which GDB is run.
6544 It holds an exact image of GDB's internal symbol table. It cannot be
6545 shared across multiple host platforms.
6547 * longjmp() handling
6549 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6550 siglongjmp() without losing control. This feature has not yet been ported to
6551 all systems. It currently works on many 386 platforms, all MIPS-based
6552 platforms (SGI, DECstation, etc), and Sun3/4.
6556 Preliminary work has been put in to support the new Solaris OS from Sun. At
6557 this time, it can control and debug processes, but it is not capable of
6562 As always, many many bug fixes. The major areas were with g++, and mipsread.
6563 People using the MIPS-based platforms should experience fewer mysterious
6564 crashes and trashed symbol tables.
6566 *** Changes in GDB-4.4:
6568 * New machines supported (host and target)
6570 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6572 BSD Reno on Vax vax-dec-bsd
6573 Ultrix on Vax vax-dec-ultrix
6575 * New machines supported (target)
6577 AMD 29000 embedded, using EBMON a29k-none-none
6581 GDB continues to improve its handling of C++. `References' work better.
6582 The demangler has also been improved, and now deals with symbols mangled as
6583 per the Annotated C++ Reference Guide.
6585 GDB also now handles `stabs' symbol information embedded in MIPS
6586 `ecoff' symbol tables. Since the ecoff format was not easily
6587 extensible to handle new languages such as C++, this appeared to be a
6588 good way to put C++ debugging info into MIPS binaries. This option
6589 will be supported in the GNU C compiler, version 2, when it is
6592 * New features for SVR4
6594 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6595 shared libraries. Debugging dynamically linked programs should present
6596 only minor differences from debugging statically linked programs.
6598 The `info proc' command will print out information about any process
6599 on an SVR4 system (including the one you are debugging). At the moment,
6600 it prints the address mappings of the process.
6602 If you bring up GDB on another SVR4 system, please send mail to
6603 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6605 * Better dynamic linking support in SunOS
6607 Reading symbols from shared libraries which contain debugging symbols
6608 now works properly. However, there remain issues such as automatic
6609 skipping of `transfer vector' code during function calls, which
6610 make it harder to debug code in a shared library, than to debug the
6611 same code linked statically.
6615 GDB is now using the latest `getopt' routines from the FSF. This
6616 version accepts the -- prefix for options with long names. GDB will
6617 continue to accept the old forms (-option and +option) as well.
6618 Various single letter abbreviations for options have been explicity
6619 added to the option table so that they won't get overshadowed in the
6620 future by other options that begin with the same letter.
6624 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6625 Many assorted bugs have been handled. Many more remain to be handled.
6626 See the various ChangeLog files (primarily in gdb and bfd) for details.
6629 *** Changes in GDB-4.3:
6631 * New machines supported (host and target)
6633 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6634 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6635 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6637 * Almost SCO Unix support
6639 We had hoped to support:
6640 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6641 (except for core file support), but we discovered very late in the release
6642 that it has problems with process groups that render gdb unusable. Sorry
6643 about that. I encourage people to fix it and post the fixes.
6645 * Preliminary ELF and DWARF support
6647 GDB can read ELF object files on System V Release 4, and can handle
6648 debugging records for C, in DWARF format, in ELF files. This support
6649 is preliminary. If you bring up GDB on another SVR4 system, please
6650 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6655 GDB now uses the latest `readline' library. One user-visible change
6656 is that two tabs will list possible command completions, which previously
6657 required typing M-? (meta-question mark, or ESC ?).
6661 The `stepi' bug that many of you noticed has been squashed.
6662 Many bugs in C++ have been handled. Many more remain to be handled.
6663 See the various ChangeLog files (primarily in gdb and bfd) for details.
6665 * State of the MIPS world (in case you wondered):
6667 GDB can understand the symbol tables emitted by the compilers
6668 supplied by most vendors of MIPS-based machines, including DEC. These
6669 symbol tables are in a format that essentially nobody else uses.
6671 Some versions of gcc come with an assembler post-processor called
6672 mips-tfile. This program is required if you want to do source-level
6673 debugging of gcc-compiled programs. I believe FSF does not ship
6674 mips-tfile with gcc version 1, but it will eventually come with gcc
6677 Debugging of g++ output remains a problem. g++ version 1.xx does not
6678 really support it at all. (If you're lucky, you should be able to get
6679 line numbers and stack traces to work, but no parameters or local
6680 variables.) With some work it should be possible to improve the
6683 When gcc version 2 is released, you will have somewhat better luck.
6684 However, even then you will get confusing results for inheritance and
6687 We will eventually provide full debugging of g++ output on
6688 DECstations. This will probably involve some kind of stabs-in-ecoff
6689 encapulation, but the details have not been worked out yet.
6692 *** Changes in GDB-4.2:
6694 * Improved configuration
6696 Only one copy of `configure' exists now, and it is not self-modifying.
6697 Porting BFD is simpler.
6701 The `step' and `next' commands now only stop at the first instruction
6702 of a source line. This prevents the multiple stops that used to occur
6703 in switch statements, for-loops, etc. `Step' continues to stop if a
6704 function that has debugging information is called within the line.
6708 Lots of small bugs fixed. More remain.
6710 * New host supported (not target)
6712 Intel 386 PC clone running Mach i386-none-mach
6715 *** Changes in GDB-4.1:
6717 * Multiple source language support
6719 GDB now has internal scaffolding to handle several source languages.
6720 It determines the type of each source file from its filename extension,
6721 and will switch expression parsing and number formatting to match the
6722 language of the function in the currently selected stack frame.
6723 You can also specifically set the language to be used, with
6724 `set language c' or `set language modula-2'.
6728 GDB now has preliminary support for the GNU Modula-2 compiler,
6729 currently under development at the State University of New York at
6730 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6731 continue through the fall of 1991 and into 1992.
6733 Other Modula-2 compilers are currently not supported, and attempting to
6734 debug programs compiled with them will likely result in an error as the
6735 symbol table is read. Feel free to work on it, though!
6737 There are hooks in GDB for strict type checking and range checking,
6738 in the `Modula-2 philosophy', but they do not currently work.
6742 GDB can now write to executable and core files (e.g. patch
6743 a variable's value). You must turn this switch on, specify
6744 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6745 by assigning a new value to a variable. Modifications take
6748 * Automatic SunOS shared library reading
6750 When you run your program, GDB automatically determines where its
6751 shared libraries (if any) have been loaded, and reads their symbols.
6752 The `share' command is no longer needed. This also works when
6753 examining core files.
6757 You can specify the number of lines that the `list' command shows.
6760 * New machines supported (host and target)
6762 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6763 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6764 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6766 * New hosts supported (not targets)
6768 IBM RT/PC: romp-ibm-aix or rtpc
6770 * New targets supported (not hosts)
6772 AMD 29000 embedded with COFF a29k-none-coff
6773 AMD 29000 embedded with a.out a29k-none-aout
6774 Ultracomputer remote kernel debug a29k-nyu-kern
6776 * New remote interfaces
6782 *** Changes in GDB-4.0:
6786 Wide output is wrapped at good places to make the output more readable.
6788 Gdb now supports cross-debugging from a host machine of one type to a
6789 target machine of another type. Communication with the target system
6790 is over serial lines. The ``target'' command handles connecting to the
6791 remote system; the ``load'' command will download a program into the
6792 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6793 also supports debugging of realtime processes running under VxWorks,
6794 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6795 stub on the target system.
6797 New CPUs supported include the AMD 29000 and Intel 960.
6799 GDB now reads object files and symbol tables via a ``binary file''
6800 library, which allows a single copy of GDB to debug programs of multiple
6801 object file types such as a.out and coff.
6803 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6804 refcard.dvi and refcard.ps are available to format it).
6807 * Control-Variable user interface simplified
6809 All variables that control the operation of the debugger can be set
6810 by the ``set'' command, and displayed by the ``show'' command.
6812 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6813 ``Show prompt'' produces the response:
6814 Gdb's prompt is new-gdb=>.
6816 What follows are the NEW set commands. The command ``help set'' will
6817 print a complete list of old and new set commands. ``help set FOO''
6818 will give a longer description of the variable FOO. ``show'' will show
6819 all of the variable descriptions and their current settings.
6821 confirm on/off: Enables warning questions for operations that are
6822 hard to recover from, e.g. rerunning the program while
6823 it is already running. Default is ON.
6825 editing on/off: Enables EMACS style command line editing
6826 of input. Previous lines can be recalled with
6827 control-P, the current line can be edited with control-B,
6828 you can search for commands with control-R, etc.
6831 history filename NAME: NAME is where the gdb command history
6832 will be stored. The default is .gdb_history,
6833 or the value of the environment variable
6836 history size N: The size, in commands, of the command history. The
6837 default is 256, or the value of the environment variable
6840 history save on/off: If this value is set to ON, the history file will
6841 be saved after exiting gdb. If set to OFF, the
6842 file will not be saved. The default is OFF.
6844 history expansion on/off: If this value is set to ON, then csh-like
6845 history expansion will be performed on
6846 command line input. The default is OFF.
6848 radix N: Sets the default radix for input and output. It can be set
6849 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6850 in the current radix, so "set radix 10" is always a no-op.
6852 height N: This integer value is the number of lines on a page. Default
6853 is 24, the current `stty rows'' setting, or the ``li#''
6854 setting from the termcap entry matching the environment
6857 width N: This integer value is the number of characters on a line.
6858 Default is 80, the current `stty cols'' setting, or the ``co#''
6859 setting from the termcap entry matching the environment
6862 Note: ``set screensize'' is obsolete. Use ``set height'' and
6863 ``set width'' instead.
6865 print address on/off: Print memory addresses in various command displays,
6866 such as stack traces and structure values. Gdb looks
6867 more ``symbolic'' if you turn this off; it looks more
6868 ``machine level'' with it on. Default is ON.
6870 print array on/off: Prettyprint arrays. New convenient format! Default
6873 print demangle on/off: Print C++ symbols in "source" form if on,
6876 print asm-demangle on/off: Same, for assembler level printouts
6879 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6882 * Support for Epoch Environment.
6884 The epoch environment is a version of Emacs v18 with windowing. One
6885 new command, ``inspect'', is identical to ``print'', except that if you
6886 are running in the epoch environment, the value is printed in its own
6890 * Support for Shared Libraries
6892 GDB can now debug programs and core files that use SunOS shared libraries.
6893 Symbols from a shared library cannot be referenced
6894 before the shared library has been linked with the program (this
6895 happens after you type ``run'' and before the function main() is entered).
6896 At any time after this linking (including when examining core files
6897 from dynamically linked programs), gdb reads the symbols from each
6898 shared library when you type the ``sharedlibrary'' command.
6899 It can be abbreviated ``share''.
6901 sharedlibrary REGEXP: Load shared object library symbols for files
6902 matching a unix regular expression. No argument
6903 indicates to load symbols for all shared libraries.
6905 info sharedlibrary: Status of loaded shared libraries.
6910 A watchpoint stops execution of a program whenever the value of an
6911 expression changes. Checking for this slows down execution
6912 tremendously whenever you are in the scope of the expression, but is
6913 quite useful for catching tough ``bit-spreader'' or pointer misuse
6914 problems. Some machines such as the 386 have hardware for doing this
6915 more quickly, and future versions of gdb will use this hardware.
6917 watch EXP: Set a watchpoint (breakpoint) for an expression.
6919 info watchpoints: Information about your watchpoints.
6921 delete N: Deletes watchpoint number N (same as breakpoints).
6922 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6923 enable N: Re-enables watchpoint number N (same as breakpoints).
6926 * C++ multiple inheritance
6928 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6931 * C++ exception handling
6933 Gdb now supports limited C++ exception handling. Besides the existing
6934 ability to breakpoint on an exception handler, gdb can breakpoint on
6935 the raising of an exception (before the stack is peeled back to the
6938 catch FOO: If there is a FOO exception handler in the dynamic scope,
6939 set a breakpoint to catch exceptions which may be raised there.
6940 Multiple exceptions (``catch foo bar baz'') may be caught.
6942 info catch: Lists all exceptions which may be caught in the
6943 current stack frame.
6946 * Minor command changes
6948 The command ``call func (arg, arg, ...)'' now acts like the print
6949 command, except it does not print or save a value if the function's result
6950 is void. This is similar to dbx usage.
6952 The ``up'' and ``down'' commands now always print the frame they end up
6953 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6954 frames without printing.
6956 * New directory command
6958 'dir' now adds directories to the FRONT of the source search path.
6959 The path starts off empty. Source files that contain debug information
6960 about the directory in which they were compiled can be found even
6961 with an empty path; Sun CC and GCC include this information. If GDB can't
6962 find your source file in the current directory, type "dir .".
6964 * Configuring GDB for compilation
6966 For normal use, type ``./configure host''. See README or gdb.texinfo
6969 GDB now handles cross debugging. If you are remotely debugging between
6970 two different machines, type ``./configure host -target=targ''.
6971 Host is the machine where GDB will run; targ is the machine
6972 where the program that you are debugging will run.