1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * New "--readnever" command line option instructs GDB to not read each
7 symbol file's symbolic debug information. This makes startup faster
8 but at the expense of not being able to perform symbolic debugging.
9 This option is intended for use cases where symbolic debugging will
10 not be used, e.g., when you only need to dump the debuggee's core.
12 * GDB now uses the GNU MPFR library, if available, to emulate target
13 floating-point arithmetic during expression evaluation when the target
14 uses different floating-point formats than the host. At least version
15 3.1 of GNU MPFR is required.
17 * GDB now supports access to the guarded-storage-control registers and the
18 software-based guarded-storage broadcast control registers on IBM z14.
20 * On Unix systems, GDB now supports transmitting environment variables
21 that are to be set or unset to GDBserver. These variables will
22 affect the environment to be passed to the remote inferior.
24 To inform GDB of environment variables that are to be transmitted to
25 GDBserver, use the "set environment" command. Only user set
26 environment variables are sent to GDBserver.
28 To inform GDB of environment variables that are to be unset before
29 the remote inferior is started by the GDBserver, use the "unset
32 * Completion improvements
34 ** GDB can now complete function parameters in linespecs and
35 explicit locations without quoting. When setting breakpoints,
36 quoting around functions names to help with TAB-completion is
37 generally no longer necessary. For example, this now completes
40 (gdb) b function(in[TAB]
43 Related, GDB is no longer confused with completing functions in
44 C++ anonymous namespaces:
47 (gdb) b (anonymous namespace)::[TAB][TAB]
48 (anonymous namespace)::a_function()
49 (anonymous namespace)::b_function()
51 ** GDB now has much improved linespec and explicit locations TAB
52 completion support, that better understands what you're
53 completing and offers better suggestions. For example, GDB no
54 longer offers data symbols as possible completions when you're
57 ** GDB now TAB-completes label symbol names.
59 ** The "complete" command now mimics TAB completion accurately.
61 * New command line options (gcore)
64 Dump all memory mappings.
66 * Breakpoints on C++ functions are now set on all scopes by default
68 By default, breakpoints on functions/methods are now interpreted as
69 specifying all functions with the given name ignoring missing
70 leading scopes (namespaces and classes).
72 For example, assuming a C++ program with symbols named:
77 both commands "break func()" and "break B::func()" set a breakpoint
80 You can use the new flag "-qualified" to override this. This makes
81 GDB interpret the specified function name as a complete
82 fully-qualified name instead. For example, using the same C++
83 program, the "break -q B::func" command sets a breakpoint on
86 * Breakpoints on functions marked with C++ ABI tags
88 GDB can now set breakpoints on functions marked with C++ ABI tags
89 (e.g., [abi:cxx11]). See here for a description of ABI tags:
90 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
92 Functions with a C++11 abi tag are demangled/displayed like this:
94 function[abi:cxx11](int)
97 You can now set a breakpoint on such functions simply as if they had
100 (gdb) b function(int)
102 Or if you need to disambiguate between tags, like:
104 (gdb) b function[abi:other_tag](int)
106 Tab completion was adjusted accordingly as well.
110 ** New events gdb.new_inferior, gdb.inferior_deleted, and
111 gdb.new_thread are emitted. See the manual for further
112 description of these.
114 ** A new command, "rbreak" has been added to the Python API. This
115 command allows the setting of a large number of breakpoints via a
116 regex pattern in Python. See the manual for further details.
118 * New features in the GDB remote stub, GDBserver
120 ** GDBserver is now able to start inferior processes with a
121 specified initial working directory.
123 The user can set the desired working directory to be used from
124 GDB using the new "set cwd" command.
126 ** New "--selftest" command line option runs some GDBserver self
127 tests. These self tests are disabled in releases.
129 ** On Unix systems, GDBserver now does globbing expansion and variable
130 substitution in inferior command line arguments.
132 This is done by starting inferiors using a shell, like GDB does.
133 See "set startup-with-shell" in the user manual for how to disable
134 this from GDB when using "target extended-remote". When using
135 "target remote", you can disable the startup with shell by using the
136 new "--no-startup-with-shell" GDBserver command line option.
138 ** On Unix systems, GDBserver now supports receiving environment
139 variables that are to be set or unset from GDB. These variables
140 will affect the environment to be passed to the inferior.
142 * When catching an Ada exception raised with a message, GDB now prints
143 the message in the catchpoint hit notification. In GDB/MI mode, that
144 information is provided as an extra field named "exception-message"
145 in the *stopped notification.
147 * Trait objects can now be inspected When debugging Rust code. This
148 requires compiler support which will appear in Rust 1.24.
152 QEnvironmentHexEncoded
153 Inform GDBserver of an environment variable that is to be passed to
154 the inferior when starting it.
157 Inform GDBserver of an environment variable that is to be unset
158 before starting the remote inferior.
161 Inform GDBserver that the environment should be reset (i.e.,
162 user-set environment variables should be unset).
165 Indicates whether the inferior must be started with a shell or not.
168 Tell GDBserver that the inferior to be started should use a specific
171 * The "maintenance print c-tdesc" command now takes an optional
172 argument which is the file name of XML target description.
174 * The "maintenance selftest" command now takes an optional argument to
175 filter the tests to be run.
177 * The "enable", and "disable" commands now accept a range of
178 breakpoint locations, e.g. "enable 1.3-5".
183 Set and show the current working directory for the inferior.
186 Set and show compilation command used for compiling and injecting code
187 with the 'compile' commands.
189 set debug separate-debug-file
190 show debug separate-debug-file
191 Control the display of debug output about separate debug file search.
193 set dump-excluded-mappings
194 show dump-excluded-mappings
195 Control whether mappings marked with the VM_DONTDUMP flag should be
196 dumped when generating a core file.
199 List the registered selftests.
202 Start the debugged program stopping at the first instruction.
204 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
207 * Safer/improved support for debugging with no debug info
209 GDB no longer assumes functions with no debug information return
212 This means that GDB now refuses to call such functions unless you
213 tell it the function's type, by either casting the call to the
214 declared return type, or by casting the function to a function
215 pointer of the right type, and calling that:
217 (gdb) p getenv ("PATH")
218 'getenv' has unknown return type; cast the call to its declared return type
219 (gdb) p (char *) getenv ("PATH")
220 $1 = 0x7fffffffe "/usr/local/bin:/"...
221 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
222 $2 = 0x7fffffffe "/usr/local/bin:/"...
224 Similarly, GDB no longer assumes that global variables with no debug
225 info have type 'int', and refuses to print the variable's value
226 unless you tell it the variable's type:
229 'var' has unknown type; cast it to its declared type
233 * New native configurations
235 FreeBSD/aarch64 aarch64*-*-freebsd*
236 FreeBSD/arm arm*-*-freebsd*
240 FreeBSD/aarch64 aarch64*-*-freebsd*
241 FreeBSD/arm arm*-*-freebsd*
243 * Removed targets and native configurations
245 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
247 *** Changes in GDB 8.0
249 * GDB now supports access to the PKU register on GNU/Linux. The register is
250 added by the Memory Protection Keys for Userspace feature which will be
251 available in future Intel CPUs.
253 * GDB now supports C++11 rvalue references.
257 ** New functions to start, stop and access a running btrace recording.
258 ** Rvalue references are now supported in gdb.Type.
260 * GDB now supports recording and replaying rdrand and rdseed Intel 64
263 * Building GDB and GDBserver now requires a C++11 compiler.
265 For example, GCC 4.8 or later.
267 It is no longer possible to build GDB or GDBserver with a C
268 compiler. The --disable-build-with-cxx configure option has been
271 * Building GDB and GDBserver now requires GNU make >= 3.81.
273 It is no longer supported to build GDB or GDBserver with another
274 implementation of the make program or an earlier version of GNU make.
276 * Native debugging on MS-Windows supports command-line redirection
278 Command-line arguments used for starting programs on MS-Windows can
279 now include redirection symbols supported by native Windows shells,
280 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
281 as "run", "start", and "set args", as well as the corresponding MI
284 * Support for thread names on MS-Windows.
286 GDB now catches and handles the special exception that programs
287 running on MS-Windows use to assign names to threads in the
290 * Support for Java programs compiled with gcj has been removed.
292 * User commands now accept an unlimited number of arguments.
293 Previously, only up to 10 was accepted.
295 * The "eval" command now expands user-defined command arguments.
297 This makes it easier to process a variable number of arguments:
302 eval "print $arg%d", $i
307 * Target descriptions can now describe registers for sparc32 and sparc64.
309 * GDB now supports DWARF version 5 (debug information format).
310 Its .debug_names index is not yet supported.
312 * New native configurations
314 FreeBSD/mips mips*-*-freebsd
318 Synopsys ARC arc*-*-elf32
319 FreeBSD/mips mips*-*-freebsd
321 * Removed targets and native configurations
323 Alpha running FreeBSD alpha*-*-freebsd*
324 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
329 Erases all the flash memory regions reported by the target.
331 maint print arc arc-instruction address
332 Print internal disassembler information about instruction at a given address.
336 set disassembler-options
337 show disassembler-options
338 Controls the passing of target specific information to the disassembler.
339 If it is necessary to specify more than one disassembler option then
340 multiple options can be placed together into a comma separated list.
341 The default value is the empty string. Currently, the only supported
342 targets are ARM, PowerPC and S/390.
347 Erases all the flash memory regions reported by the target. This is
348 equivalent to the CLI command flash-erase.
350 -file-list-shared-libraries
351 List the shared libraries in the program. This is
352 equivalent to the CLI command "info shared".
354 *** Changes in GDB 7.12
356 * GDB and GDBserver now build with a C++ compiler by default.
358 The --enable-build-with-cxx configure option is now enabled by
359 default. One must now explicitly configure with
360 --disable-build-with-cxx in order to build with a C compiler. This
361 option will be removed in a future release.
363 * GDBserver now supports recording btrace without maintaining an active
366 * GDB now supports a negative repeat count in the 'x' command to examine
367 memory backward from the given address. For example:
370 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
371 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
372 (gdb) x/-5i 0x0000000000400580
373 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
374 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
375 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
376 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
377 0x40057b <main(int, char**)+25>:
378 callq 0x400536 <Func1(int, char const*)>
380 * Fortran: Support structures with fields of dynamic types and
381 arrays of dynamic types.
383 * The symbol dumping maintenance commands have new syntax.
384 maint print symbols [-pc address] [--] [filename]
385 maint print symbols [-objfile objfile] [-source source] [--] [filename]
386 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
387 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
388 maint print msymbols [-objfile objfile] [--] [filename]
390 * GDB now supports multibit bitfields and enums in target register
393 * New Python-based convenience function $_as_string(val), which returns
394 the textual representation of a value. This function is especially
395 useful to obtain the text label of an enum value.
397 * Intel MPX bound violation handling.
399 Segmentation faults caused by a Intel MPX boundary violation
400 now display the kind of violation (upper or lower), the memory
401 address accessed and the memory bounds, along with the usual
402 signal received and code location.
406 Program received signal SIGSEGV, Segmentation fault
407 Upper bound violation while accessing address 0x7fffffffc3b3
408 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
409 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
411 * Rust language support.
412 GDB now supports debugging programs written in the Rust programming
413 language. See https://www.rust-lang.org/ for more information about
416 * Support for running interpreters on specified input/output devices
418 GDB now supports a new mechanism that allows frontends to provide
419 fully featured GDB console views, as a better alternative to
420 building such views on top of the "-interpreter-exec console"
421 command. See the new "new-ui" command below. With that command,
422 frontends can now start GDB in the traditional command-line mode
423 running in an embedded terminal emulator widget, and create a
424 separate MI interpreter running on a specified i/o device. In this
425 way, GDB handles line editing, history, tab completion, etc. in the
426 console all by itself, and the GUI uses the separate MI interpreter
427 for its own control and synchronization, invisible to the command
430 * The "catch syscall" command catches groups of related syscalls.
432 The "catch syscall" command now supports catching a group of related
433 syscalls using the 'group:' or 'g:' prefix.
438 skip -gfile file-glob-pattern
439 skip -function function
440 skip -rfunction regular-expression
441 A generalized form of the skip command, with new support for
442 glob-style file names and regular expressions for function names.
443 Additionally, a file spec and a function spec may now be combined.
445 maint info line-table REGEXP
446 Display the contents of GDB's internal line table data struture.
449 Run any GDB unit tests that were compiled in.
452 Start a new user interface instance running INTERP as interpreter,
453 using the TTY file for input/output.
457 ** gdb.Breakpoint objects have a new attribute "pending", which
458 indicates whether the breakpoint is pending.
459 ** Three new breakpoint-related events have been added:
460 gdb.breakpoint_created, gdb.breakpoint_modified, and
461 gdb.breakpoint_deleted.
464 Signal ("set") the given MS-Windows event object. This is used in
465 conjunction with the Windows JIT debugging (AeDebug) support, where
466 the OS suspends a crashing process until a debugger can attach to
467 it. Resuming the crashing process, in order to debug it, is done by
470 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
471 was added in GDBserver, including JIT compiling fast tracepoint's
472 conditional expression bytecode into native code.
474 * Support for various remote target protocols and ROM monitors has
477 target m32rsdi Remote M32R debugging over SDI
478 target mips MIPS remote debugging protocol
479 target pmon PMON ROM monitor
480 target ddb NEC's DDB variant of PMON for Vr4300
481 target rockhopper NEC RockHopper variant of PMON
482 target lsi LSI variant of PMO
484 * Support for tracepoints and fast tracepoints on powerpc-linux,
485 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
486 including JIT compiling fast tracepoint's conditional expression
487 bytecode into native code.
489 * MI async record =record-started now includes the method and format used for
490 recording. For example:
492 =record-started,thread-group="i1",method="btrace",format="bts"
494 * MI async record =thread-selected now includes the frame field. For example:
496 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
500 Andes NDS32 nds32*-*-elf
502 *** Changes in GDB 7.11
504 * GDB now supports debugging kernel-based threads on FreeBSD.
506 * Per-inferior thread numbers
508 Thread numbers are now per inferior instead of global. If you're
509 debugging multiple inferiors, GDB displays thread IDs using a
510 qualified INF_NUM.THR_NUM form. For example:
514 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
515 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
516 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
517 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
519 As consequence, thread numbers as visible in the $_thread
520 convenience variable and in Python's InferiorThread.num attribute
521 are no longer unique between inferiors.
523 GDB now maintains a second thread ID per thread, referred to as the
524 global thread ID, which is the new equivalent of thread numbers in
525 previous releases. See also $_gthread below.
527 For backwards compatibility, MI's thread IDs always refer to global
530 * Commands that accept thread IDs now accept the qualified
531 INF_NUM.THR_NUM form as well. For example:
534 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
537 * In commands that accept a list of thread IDs, you can now refer to
538 all threads of an inferior using a star wildcard. GDB accepts
539 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
540 refer to all threads of the current inferior. For example, "info
543 * You can use "info threads -gid" to display the global thread ID of
546 * The new convenience variable $_gthread holds the global number of
549 * The new convenience variable $_inferior holds the number of the
552 * GDB now displays the ID and name of the thread that hit a breakpoint
553 or received a signal, if your program is multi-threaded. For
556 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
557 Thread 1 "main" received signal SIGINT, Interrupt.
559 * Record btrace now supports non-stop mode.
561 * Support for tracepoints on aarch64-linux was added in GDBserver.
563 * The 'record instruction-history' command now indicates speculative execution
564 when using the Intel Processor Trace recording format.
566 * GDB now allows users to specify explicit locations, bypassing
567 the linespec parser. This feature is also available to GDB/MI
570 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
571 GDB now is able to debug both AArch64 applications and ARM applications
574 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
575 including JIT compiling fast tracepoint's conditional expression bytecode
578 * GDB now supports displaced stepping on AArch64 GNU/Linux.
580 * "info threads", "info inferiors", "info display", "info checkpoints"
581 and "maint info program-spaces" now list the corresponding items in
582 ascending ID order, for consistency with all other "info" commands.
584 * In Ada, the overloads selection menu has been enhanced to display the
585 parameter types and the return types for the matching overloaded subprograms.
589 maint set target-non-stop (on|off|auto)
590 maint show target-non-stop
591 Control whether GDB targets always operate in non-stop mode even if
592 "set non-stop" is "off". The default is "auto", meaning non-stop
593 mode is enabled if supported by the target.
595 maint set bfd-sharing
596 maint show bfd-sharing
597 Control the reuse of bfd objects.
601 Control display of debugging info regarding bfd caching.
605 Control display of debugging info regarding FreeBSD threads.
607 set remote multiprocess-extensions-packet
608 show remote multiprocess-extensions-packet
609 Set/show the use of the remote protocol multiprocess extensions.
611 set remote thread-events
612 show remote thread-events
613 Set/show the use of thread create/exit events.
615 set ada print-signatures on|off
616 show ada print-signatures"
617 Control whether parameter types and return types are displayed in overloads
618 selection menus. It is activaled (@code{on}) by default.
622 Controls the maximum size of memory, in bytes, that GDB will
623 allocate for value contents. Prevents incorrect programs from
624 causing GDB to allocate overly large buffers. Default is 64k.
626 * The "disassemble" command accepts a new modifier: /s.
627 It prints mixed source+disassembly like /m with two differences:
628 - disassembled instructions are now printed in program order, and
629 - and source for all relevant files is now printed.
630 The "/m" option is now considered deprecated: its "source-centric"
631 output hasn't proved useful in practice.
633 * The "record instruction-history" command accepts a new modifier: /s.
634 It behaves exactly like /m and prints mixed source+disassembly.
636 * The "set scheduler-locking" command supports a new mode "replay".
637 It behaves like "off" in record mode and like "on" in replay mode.
639 * Support for various ROM monitors has been removed:
641 target dbug dBUG ROM monitor for Motorola ColdFire
642 target picobug Motorola picobug monitor
643 target dink32 DINK32 ROM monitor for PowerPC
644 target m32r Renesas M32R/D ROM monitor
645 target mon2000 mon2000 ROM monitor
646 target ppcbug PPCBUG ROM monitor for PowerPC
648 * Support for reading/writing memory and extracting values on architectures
649 whose memory is addressable in units of any integral multiple of 8 bits.
654 Indicates that an exec system call was executed.
656 exec-events feature in qSupported
657 The qSupported packet allows GDB to request support for exec
658 events using the new 'gdbfeature' exec-event, and the qSupported
659 response can contain the corresponding 'stubfeature'. Set and
660 show commands can be used to display whether these features are enabled.
663 Equivalent to interrupting with the ^C character, but works in
666 thread created stop reason (T05 create:...)
667 Indicates that the thread was just created and is stopped at entry.
669 thread exit stop reply (w exitcode;tid)
670 Indicates that the thread has terminated.
673 Enables/disables thread create and exit event reporting. For
674 example, this is used in non-stop mode when GDB stops a set of
675 threads and synchronously waits for the their corresponding stop
676 replies. Without exit events, if one of the threads exits, GDB
677 would hang forever not knowing that it should no longer expect a
678 stop for that same thread.
681 Indicates that there are no resumed threads left in the target (all
682 threads are stopped). The remote stub reports support for this stop
683 reply to GDB's qSupported query.
686 Enables/disables catching syscalls from the inferior process.
687 The remote stub reports support for this packet to GDB's qSupported query.
689 syscall_entry stop reason
690 Indicates that a syscall was just called.
692 syscall_return stop reason
693 Indicates that a syscall just returned.
695 * Extended-remote exec events
697 ** GDB now has support for exec events on extended-remote Linux targets.
698 For such targets with Linux kernels 2.5.46 and later, this enables
699 follow-exec-mode and exec catchpoints.
701 set remote exec-event-feature-packet
702 show remote exec-event-feature-packet
703 Set/show the use of the remote exec event feature.
705 * Thread names in remote protocol
707 The reply to qXfer:threads:read may now include a name attribute for each
710 * Target remote mode fork and exec events
712 ** GDB now has support for fork and exec events on target remote mode
713 Linux targets. For such targets with Linux kernels 2.5.46 and later,
714 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
715 fork and exec catchpoints.
717 * Remote syscall events
719 ** GDB now has support for catch syscall on remote Linux targets,
720 currently enabled on x86/x86_64 architectures.
722 set remote catch-syscall-packet
723 show remote catch-syscall-packet
724 Set/show the use of the remote catch syscall feature.
728 ** The -var-set-format command now accepts the zero-hexadecimal
729 format. It outputs data in hexadecimal format with zero-padding on the
734 ** gdb.InferiorThread objects have a new attribute "global_num",
735 which refers to the thread's global thread ID. The existing
736 "num" attribute now refers to the thread's per-inferior number.
737 See "Per-inferior thread numbers" above.
738 ** gdb.InferiorThread objects have a new attribute "inferior", which
739 is the Inferior object the thread belongs to.
741 *** Changes in GDB 7.10
743 * Support for process record-replay and reverse debugging on aarch64*-linux*
744 targets has been added. GDB now supports recording of A64 instruction set
745 including advance SIMD instructions.
747 * Support for Sun's version of the "stabs" debug file format has been removed.
749 * GDB now honors the content of the file /proc/PID/coredump_filter
750 (PID is the process ID) on GNU/Linux systems. This file can be used
751 to specify the types of memory mappings that will be included in a
752 corefile. For more information, please refer to the manual page of
753 "core(5)". GDB also has a new command: "set use-coredump-filter
754 on|off". It allows to set whether GDB will read the content of the
755 /proc/PID/coredump_filter file when generating a corefile.
757 * The "info os" command on GNU/Linux can now display information on
759 "info os cpus" Listing of all cpus/cores on the system
761 * GDB has two new commands: "set serial parity odd|even|none" and
762 "show serial parity". These allows to set or show parity for the
765 * The "info source" command now displays the producer string if it was
766 present in the debug info. This typically includes the compiler version
767 and may include things like its command line arguments.
769 * The "info dll", an alias of the "info sharedlibrary" command,
770 is now available on all platforms.
772 * Directory names supplied to the "set sysroot" commands may be
773 prefixed with "target:" to tell GDB to access shared libraries from
774 the target system, be it local or remote. This replaces the prefix
775 "remote:". The default sysroot has been changed from "" to
776 "target:". "remote:" is automatically converted to "target:" for
777 backward compatibility.
779 * The system root specified by "set sysroot" will be prepended to the
780 filename of the main executable (if reported to GDB as absolute by
781 the operating system) when starting processes remotely, and when
782 attaching to already-running local or remote processes.
784 * GDB now supports automatic location and retrieval of executable
785 files from remote targets. Remote debugging can now be initiated
786 using only a "target remote" or "target extended-remote" command
787 (no "set sysroot" or "file" commands are required). See "New remote
790 * The "dump" command now supports verilog hex format.
792 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
794 * On GNU/Linux, GDB and gdbserver are now able to access executable
795 and shared library files without a "set sysroot" command when
796 attaching to processes running in different mount namespaces from
797 the debugger. This makes it possible to attach to processes in
798 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
799 See "New remote packets" below.
801 * The "tui reg" command now provides completion for all of the
802 available register groups, including target specific groups.
804 * The HISTSIZE environment variable is no longer read when determining
805 the size of GDB's command history. GDB now instead reads the dedicated
806 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
807 disables truncation of command history. Non-numeric values of GDBHISTSIZE
812 ** Memory ports can now be unbuffered.
816 ** gdb.Objfile objects have a new attribute "username",
817 which is the name of the objfile as specified by the user,
818 without, for example, resolving symlinks.
819 ** You can now write frame unwinders in Python.
820 ** gdb.Type objects have a new method "optimized_out",
821 returning optimized out gdb.Value instance of this type.
822 ** gdb.Value objects have new methods "reference_value" and
823 "const_value" which return a reference to the value and a
824 "const" version of the value respectively.
828 maint print symbol-cache
829 Print the contents of the symbol cache.
831 maint print symbol-cache-statistics
832 Print statistics of symbol cache usage.
834 maint flush-symbol-cache
835 Flush the contents of the symbol cache.
839 Start branch trace recording using Branch Trace Store (BTS) format.
842 Evaluate expression by using the compiler and print result.
846 Explicit commands for enabling and disabling tui mode.
849 set mpx bound on i386 and amd64
850 Support for bound table investigation on Intel MPX enabled applications.
854 Start branch trace recording using Intel Processor Trace format.
857 Print information about branch tracing internals.
859 maint btrace packet-history
860 Print the raw branch tracing data.
862 maint btrace clear-packet-history
863 Discard the stored raw branch tracing data.
866 Discard all branch tracing data. It will be fetched and processed
867 anew by the next "record" command.
872 Renamed from "set debug dwarf2-die".
874 Renamed from "show debug dwarf2-die".
877 Renamed from "set debug dwarf2-read".
878 show debug dwarf-read
879 Renamed from "show debug dwarf2-read".
881 maint set dwarf always-disassemble
882 Renamed from "maint set dwarf2 always-disassemble".
883 maint show dwarf always-disassemble
884 Renamed from "maint show dwarf2 always-disassemble".
886 maint set dwarf max-cache-age
887 Renamed from "maint set dwarf2 max-cache-age".
888 maint show dwarf max-cache-age
889 Renamed from "maint show dwarf2 max-cache-age".
892 show debug dwarf-line
893 Control display of debugging info regarding DWARF line processing.
897 Set the maximum number of candidates to be considered during
898 completion. The default value is 200. This limit allows GDB
899 to avoid generating large completion lists, the computation of
900 which can cause the debugger to become temporarily unresponsive.
902 set history remove-duplicates
903 show history remove-duplicates
904 Control the removal of duplicate history entries.
906 maint set symbol-cache-size
907 maint show symbol-cache-size
908 Control the size of the symbol cache.
910 set|show record btrace bts buffer-size
911 Set and show the size of the ring buffer used for branch tracing in
913 The obtained size may differ from the requested size. Use "info
914 record" to see the obtained buffer size.
916 set debug linux-namespaces
917 show debug linux-namespaces
918 Control display of debugging info regarding Linux namespaces.
920 set|show record btrace pt buffer-size
921 Set and show the size of the ring buffer used for branch tracing in
922 Intel Processor Trace format.
923 The obtained size may differ from the requested size. Use "info
924 record" to see the obtained buffer size.
926 maint set|show btrace pt skip-pad
927 Set and show whether PAD packets are skipped when computing the
930 * The command 'thread apply all' can now support new option '-ascending'
931 to call its specified command for all threads in ascending order.
933 * Python/Guile scripting
935 ** GDB now supports auto-loading of Python/Guile scripts contained in the
936 special section named `.debug_gdb_scripts'.
940 qXfer:btrace-conf:read
941 Return the branch trace configuration for the current thread.
943 Qbtrace-conf:bts:size
944 Set the requested ring buffer size for branch tracing in BTS format.
947 Enable Intel Procesor Trace-based branch tracing for the current
948 process. The remote stub reports support for this packet to GDB's
952 Set the requested ring buffer size for branch tracing in Intel Processor
956 Indicates a memory breakpoint instruction was executed, irrespective
957 of whether it was GDB that planted the breakpoint or the breakpoint
958 is hardcoded in the program. This is required for correct non-stop
962 Indicates the target stopped for a hardware breakpoint. This is
963 required for correct non-stop mode operation.
966 Return information about files on the remote system.
969 Return the full absolute name of the file that was executed to
970 create a process running on the remote system.
973 Select the filesystem on which vFile: operations with filename
974 arguments will operate. This is required for GDB to be able to
975 access files on remote targets where the remote stub does not
976 share a common filesystem with the inferior(s).
979 Indicates that a fork system call was executed.
982 Indicates that a vfork system call was executed.
984 vforkdone stop reason
985 Indicates that a vfork child of the specified process has executed
986 an exec or exit, allowing the vfork parent to resume execution.
988 fork-events and vfork-events features in qSupported
989 The qSupported packet allows GDB to request support for fork and
990 vfork events using new 'gdbfeatures' fork-events and vfork-events,
991 and the qSupported response can contain the corresponding
992 'stubfeatures'. Set and show commands can be used to display
993 whether these features are enabled.
995 * Extended-remote fork events
997 ** GDB now has support for fork events on extended-remote Linux
998 targets. For targets with Linux kernels 2.5.60 and later, this
999 enables follow-fork-mode and detach-on-fork for both fork and
1000 vfork, as well as fork and vfork catchpoints.
1002 * The info record command now shows the recording format and the
1003 branch tracing configuration for the current thread when using
1004 the btrace record target.
1005 For the BTS format, it shows the ring buffer size.
1007 * GDB now has support for DTrace USDT (Userland Static Defined
1008 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1010 * GDB now supports access to vector registers on S/390 GNU/Linux
1013 * Removed command line options
1015 -xdb HP-UX XDB compatibility mode.
1017 * Removed targets and native configurations
1019 HP/PA running HP-UX hppa*-*-hpux*
1020 Itanium running HP-UX ia64-*-hpux*
1022 * New configure options
1025 This configure option allows the user to build GDB with support for
1026 Intel Processor Trace (default: auto). This requires libipt.
1028 --with-libipt-prefix=PATH
1029 Specify the path to the version of libipt that GDB should use.
1030 $PATH/include should contain the intel-pt.h header and
1031 $PATH/lib should contain the libipt.so library.
1033 *** Changes in GDB 7.9.1
1037 ** Xmethods can now specify a result type.
1039 *** Changes in GDB 7.9
1041 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1045 ** You can now access frame registers from Python scripts.
1046 ** New attribute 'producer' for gdb.Symtab objects.
1047 ** gdb.Objfile objects have a new attribute "progspace",
1048 which is the gdb.Progspace object of the containing program space.
1049 ** gdb.Objfile objects have a new attribute "owner".
1050 ** gdb.Objfile objects have a new attribute "build_id",
1051 which is the build ID generated when the file was built.
1052 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1053 ** A new event "gdb.clear_objfiles" has been added, triggered when
1054 selecting a new file to debug.
1055 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1056 ** New function gdb.lookup_objfile.
1058 New events which are triggered when GDB modifies the state of the
1061 ** gdb.events.inferior_call_pre: Function call is about to be made.
1062 ** gdb.events.inferior_call_post: Function call has just been made.
1063 ** gdb.events.memory_changed: A memory location has been altered.
1064 ** gdb.events.register_changed: A register has been altered.
1066 * New Python-based convenience functions:
1068 ** $_caller_is(name [, number_of_frames])
1069 ** $_caller_matches(regexp [, number_of_frames])
1070 ** $_any_caller_is(name [, number_of_frames])
1071 ** $_any_caller_matches(regexp [, number_of_frames])
1073 * GDB now supports the compilation and injection of source code into
1074 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1075 to compile the source code to object code, and if successful, inject
1076 and execute that code within the current context of the inferior.
1077 Currently the C language is supported. The commands used to
1078 interface with this new feature are:
1080 compile code [-raw|-r] [--] [source code]
1081 compile file [-raw|-r] filename
1085 demangle [-l language] [--] name
1086 Demangle "name" in the specified language, or the current language
1087 if elided. This command is renamed from the "maint demangle" command.
1088 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1089 as "maint demangler-warning".
1091 queue-signal signal-name-or-number
1092 Queue a signal to be delivered to the thread when it is resumed.
1094 add-auto-load-scripts-directory directory
1095 Add entries to the list of directories from which to load auto-loaded
1098 maint print user-registers
1099 List all currently available "user" registers.
1101 compile code [-r|-raw] [--] [source code]
1102 Compile, inject, and execute in the inferior the executable object
1103 code produced by compiling the provided source code.
1105 compile file [-r|-raw] filename
1106 Compile and inject into the inferior the executable object code
1107 produced by compiling the source code stored in the filename
1110 * On resume, GDB now always passes the signal the program had stopped
1111 for to the thread the signal was sent to, even if the user changed
1112 threads before resuming. Previously GDB would often (but not
1113 always) deliver the signal to the thread that happens to be current
1116 * Conversely, the "signal" command now consistently delivers the
1117 requested signal to the current thread. GDB now asks for
1118 confirmation if the program had stopped for a signal and the user
1119 switched threads meanwhile.
1121 * "breakpoint always-inserted" modes "off" and "auto" merged.
1123 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1124 won't remove breakpoints from the target until all threads stop,
1125 even in non-stop mode. The "auto" mode has been removed, and "off"
1126 is now the default mode.
1130 set debug symbol-lookup
1131 show debug symbol-lookup
1132 Control display of debugging info regarding symbol lookup.
1136 ** The -list-thread-groups command outputs an exit-code field for
1137 inferiors that have exited.
1141 MIPS SDE mips*-sde*-elf*
1145 Support for these obsolete configurations has been removed.
1147 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1148 SGI Irix-5.x mips-*-irix5*
1149 SGI Irix-6.x mips-*-irix6*
1150 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1151 VAX running Ultrix vax-*-ultrix*
1153 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1154 and "assf"), have been removed. Use the "sharedlibrary" command, or
1155 its alias "share", instead.
1157 *** Changes in GDB 7.8
1159 * New command line options
1162 This is an alias for the --data-directory option.
1164 * GDB supports printing and modifying of variable length automatic arrays
1165 as specified in ISO C99.
1167 * The ARM simulator now supports instruction level tracing
1168 with or without disassembly.
1172 GDB now has support for scripting using Guile. Whether this is
1173 available is determined at configure time.
1174 Guile version 2.0 or greater is required.
1175 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1177 * New commands (for set/show, see "New options" below)
1181 Invoke CODE by passing it to the Guile interpreter.
1185 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1187 info auto-load guile-scripts [regexp]
1188 Print the list of automatically loaded Guile scripts.
1190 * The source command is now capable of sourcing Guile scripts.
1191 This feature is dependent on the debugger being built with Guile support.
1195 set print symbol-loading (off|brief|full)
1196 show print symbol-loading
1197 Control whether to print informational messages when loading symbol
1198 information for a file. The default is "full", but when debugging
1199 programs with large numbers of shared libraries the amount of output
1200 becomes less useful.
1202 set guile print-stack (none|message|full)
1203 show guile print-stack
1204 Show a stack trace when an error is encountered in a Guile script.
1206 set auto-load guile-scripts (on|off)
1207 show auto-load guile-scripts
1208 Control auto-loading of Guile script files.
1210 maint ada set ignore-descriptive-types (on|off)
1211 maint ada show ignore-descriptive-types
1212 Control whether the debugger should ignore descriptive types in Ada
1213 programs. The default is not to ignore the descriptive types. See
1214 the user manual for more details on descriptive types and the intended
1215 usage of this option.
1217 set auto-connect-native-target
1219 Control whether GDB is allowed to automatically connect to the
1220 native target for the run, attach, etc. commands when not connected
1221 to any target yet. See also "target native" below.
1223 set record btrace replay-memory-access (read-only|read-write)
1224 show record btrace replay-memory-access
1225 Control what memory accesses are allowed during replay.
1227 maint set target-async (on|off)
1228 maint show target-async
1229 This controls whether GDB targets operate in synchronous or
1230 asynchronous mode. Normally the default is asynchronous, if it is
1231 available; but this can be changed to more easily debug problems
1232 occurring only in synchronous mode.
1234 set mi-async (on|off)
1236 Control whether MI asynchronous mode is preferred. This supersedes
1237 "set target-async" of previous GDB versions.
1239 * "set target-async" is deprecated as a CLI option and is now an alias
1240 for "set mi-async" (only puts MI into async mode).
1242 * Background execution commands (e.g., "c&", "s&", etc.) are now
1243 possible ``out of the box'' if the target supports them. Previously
1244 the user would need to explicitly enable the possibility with the
1245 "set target-async on" command.
1247 * New features in the GDB remote stub, GDBserver
1249 ** New option --debug-format=option1[,option2,...] allows one to add
1250 additional text to each output. At present only timestamps
1251 are supported: --debug-format=timestamps.
1252 Timestamps can also be turned on with the
1253 "monitor set debug-format timestamps" command from GDB.
1255 * The 'record instruction-history' command now starts counting instructions
1256 at one. This also affects the instruction ranges reported by the
1257 'record function-call-history' command when given the /i modifier.
1259 * The command 'record function-call-history' supports a new modifier '/c' to
1260 indent the function names based on their call stack depth.
1261 The fields for the '/i' and '/l' modifier have been reordered.
1262 The source line range is now prefixed with 'at'.
1263 The instruction range is now prefixed with 'inst'.
1264 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1265 "record instruction-history" and "list" commands.
1267 * The ranges given as arguments to the 'record function-call-history' and
1268 'record instruction-history' commands are now inclusive.
1270 * The btrace record target now supports the 'record goto' command.
1271 For locations inside the execution trace, the back trace is computed
1272 based on the information stored in the execution trace.
1274 * The btrace record target supports limited reverse execution and replay.
1275 The target does not record data and therefore does not allow reading
1276 memory or registers.
1278 * The "catch syscall" command now works on s390*-linux* targets.
1280 * The "compare-sections" command is no longer specific to target
1281 remote. It now works with all targets.
1283 * All native targets are now consistently called "native".
1284 Consequently, the "target child", "target GNU", "target djgpp",
1285 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1286 commands have been replaced with "target native". The QNX/NTO port
1287 leaves the "procfs" target in place and adds a "native" target for
1288 consistency with other ports. The impact on users should be minimal
1289 as these commands previously either throwed an error, or were
1290 no-ops. The target's name is visible in the output of the following
1291 commands: "help target", "info target", "info files", "maint print
1294 * The "target native" command now connects to the native target. This
1295 can be used to launch native programs even when "set
1296 auto-connect-native-target" is set to off.
1298 * GDB now supports access to Intel MPX registers on GNU/Linux.
1300 * Support for Intel AVX-512 registers on GNU/Linux.
1301 Support displaying and modifying Intel AVX-512 registers
1302 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1304 * New remote packets
1306 qXfer:btrace:read's annex
1307 The qXfer:btrace:read packet supports a new annex 'delta' to read
1308 branch trace incrementally.
1312 ** Valid Python operations on gdb.Value objects representing
1313 structs/classes invoke the corresponding overloaded operators if
1315 ** New `Xmethods' feature in the Python API. Xmethods are
1316 additional methods or replacements for existing methods of a C++
1317 class. This feature is useful for those cases where a method
1318 defined in C++ source code could be inlined or optimized out by
1319 the compiler, making it unavailable to GDB.
1322 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1324 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1325 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1326 its alias "share", instead.
1328 * The commands "set remotebaud" and "show remotebaud" are no longer
1329 supported. Use "set serial baud" and "show serial baud" (respectively)
1334 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1335 target-async". The latter is left as a deprecated alias of the
1336 former for backward compatibility. If the target supports it,
1337 CLI background execution commands are now always possible by
1338 default, independently of whether the frontend stated a
1339 preference for asynchronous execution with "-gdb-set mi-async".
1340 Previously "-gdb-set target-async off" affected both MI execution
1341 commands and CLI execution commands.
1343 *** Changes in GDB 7.7
1345 * Improved support for process record-replay and reverse debugging on
1346 arm*-linux* targets. Support for thumb32 and syscall instruction
1347 recording has been added.
1349 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1351 * GDB now supports Fission DWP file format version 2.
1352 http://gcc.gnu.org/wiki/DebugFission
1354 * New convenience function "$_isvoid", to check whether an expression
1355 is void. A void expression is an expression where the type of the
1356 result is "void". For example, some convenience variables may be
1357 "void" when evaluated (e.g., "$_exitcode" before the execution of
1358 the program being debugged; or an undefined convenience variable).
1359 Another example, when calling a function whose return type is
1362 * The "maintenance print objfiles" command now takes an optional regexp.
1364 * The "catch syscall" command now works on arm*-linux* targets.
1366 * GDB now consistently shows "<not saved>" when printing values of
1367 registers the debug info indicates have not been saved in the frame
1368 and there's nowhere to retrieve them from
1369 (callee-saved/call-clobbered registers):
1374 (gdb) info registers rax
1377 Before, the former would print "<optimized out>", and the latter
1378 "*value not available*".
1380 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1385 ** Frame filters and frame decorators have been added.
1386 ** Temporary breakpoints are now supported.
1387 ** Line tables representation has been added.
1388 ** New attribute 'parent_type' for gdb.Field objects.
1389 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1390 ** New attribute 'name' for gdb.Type objects.
1394 Nios II ELF nios2*-*-elf
1395 Nios II GNU/Linux nios2*-*-linux
1396 Texas Instruments MSP430 msp430*-*-elf
1398 * Removed native configurations
1400 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1401 been removed. ELF variants of these configurations are kept supported.
1403 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1404 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1405 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1406 i[34567]86-*-openbsd3.[0-3]
1407 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1408 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1409 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1413 Like "catch throw", but catches a re-thrown exception.
1414 maint check-psymtabs
1415 Renamed from old "maint check-symtabs".
1417 Perform consistency checks on symtabs.
1418 maint expand-symtabs
1419 Expand symtabs matching an optional regexp.
1422 Display the details of GDB configure-time options.
1424 maint set|show per-command
1425 maint set|show per-command space
1426 maint set|show per-command time
1427 maint set|show per-command symtab
1428 Enable display of per-command gdb resource usage.
1430 remove-symbol-file FILENAME
1431 remove-symbol-file -a ADDRESS
1432 Remove a symbol file added via add-symbol-file. The file to remove
1433 can be identified by its filename or by an address that lies within
1434 the boundaries of this symbol file in memory.
1437 info exceptions REGEXP
1438 Display the list of Ada exceptions defined in the program being
1439 debugged. If provided, only the exceptions whose names match REGEXP
1444 set debug symfile off|on
1446 Control display of debugging info regarding reading symbol files and
1447 symbol tables within those files
1449 set print raw frame-arguments
1450 show print raw frame-arguments
1451 Set/show whether to print frame arguments in raw mode,
1452 disregarding any defined pretty-printers.
1454 set remote trace-status-packet
1455 show remote trace-status-packet
1456 Set/show the use of remote protocol qTStatus packet.
1460 Control display of debugging messages related to Nios II targets.
1464 Control whether target-assisted range stepping is enabled.
1466 set startup-with-shell
1467 show startup-with-shell
1468 Specifies whether Unix child processes are started via a shell or
1473 Use the target memory cache for accesses to the code segment. This
1474 improves performance of remote debugging (particularly disassembly).
1476 * You can now use a literal value 'unlimited' for options that
1477 interpret 0 or -1 as meaning "unlimited". E.g., "set
1478 trace-buffer-size unlimited" is now an alias for "set
1479 trace-buffer-size -1" and "set height unlimited" is now an alias for
1482 * The "set debug symtab-create" debugging option of GDB has been changed to
1483 accept a verbosity level. 0 means "off", 1 provides basic debugging
1484 output, and values of 2 or greater provides more verbose output.
1486 * New command-line options
1488 Display the details of GDB configure-time options.
1490 * The command 'tsave' can now support new option '-ctf' to save trace
1491 buffer in Common Trace Format.
1493 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1496 * GDB now implements the the C++ 'typeid' operator.
1498 * The new convenience variable $_exception holds the exception being
1499 thrown or caught at an exception-related catchpoint.
1501 * The exception-related catchpoints, like "catch throw", now accept a
1502 regular expression which can be used to filter exceptions by type.
1504 * The new convenience variable $_exitsignal is automatically set to
1505 the terminating signal number when the program being debugged dies
1506 due to an uncaught signal.
1510 ** All MI commands now accept an optional "--language" option.
1511 Support for this feature can be verified by using the "-list-features"
1512 command, which should contain "language-option".
1514 ** The new command -info-gdb-mi-command allows the user to determine
1515 whether a GDB/MI command is supported or not.
1517 ** The "^error" result record returned when trying to execute an undefined
1518 GDB/MI command now provides a variable named "code" whose content is the
1519 "undefined-command" error code. Support for this feature can be verified
1520 by using the "-list-features" command, which should contain
1521 "undefined-command-error-code".
1523 ** The -trace-save MI command can optionally save trace buffer in Common
1526 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1528 ** The command -data-list-register-values now accepts an optional
1529 "--skip-unavailable" option. When used, only the available registers
1532 ** The new command -trace-frame-collected dumps collected variables,
1533 computed expressions, tvars, memory and registers in a traceframe.
1535 ** The commands -stack-list-locals, -stack-list-arguments and
1536 -stack-list-variables now accept an option "--skip-unavailable".
1537 When used, only the available locals or arguments are displayed.
1539 ** The -exec-run command now accepts an optional "--start" option.
1540 When used, the command follows the same semantics as the "start"
1541 command, stopping the program's execution at the start of its
1542 main subprogram. Support for this feature can be verified using
1543 the "-list-features" command, which should contain
1544 "exec-run-start-option".
1546 ** The new commands -catch-assert and -catch-exceptions insert
1547 catchpoints stopping the program when Ada exceptions are raised.
1549 ** The new command -info-ada-exceptions provides the equivalent of
1550 the new "info exceptions" command.
1552 * New system-wide configuration scripts
1553 A GDB installation now provides scripts suitable for use as system-wide
1554 configuration scripts for the following systems:
1558 * GDB now supports target-assigned range stepping with remote targets.
1559 This improves the performance of stepping source lines by reducing
1560 the number of control packets from/to GDB. See "New remote packets"
1563 * GDB now understands the element 'tvar' in the XML traceframe info.
1564 It has the id of the collected trace state variables.
1566 * On S/390 targets that provide the transactional-execution feature,
1567 the program interruption transaction diagnostic block (TDB) is now
1568 represented as a number of additional "registers" in GDB.
1570 * New remote packets
1574 The vCont packet supports a new 'r' action, that tells the remote
1575 stub to step through an address range itself, without GDB
1576 involvemement at each single-step.
1578 qXfer:libraries-svr4:read's annex
1579 The previously unused annex of the qXfer:libraries-svr4:read packet
1580 is now used to support passing an argument list. The remote stub
1581 reports support for this argument list to GDB's qSupported query.
1582 The defined arguments are "start" and "prev", used to reduce work
1583 necessary for library list updating, resulting in significant
1586 * New features in the GDB remote stub, GDBserver
1588 ** GDBserver now supports target-assisted range stepping. Currently
1589 enabled on x86/x86_64 GNU/Linux targets.
1591 ** GDBserver now adds element 'tvar' in the XML in the reply to
1592 'qXfer:traceframe-info:read'. It has the id of the collected
1593 trace state variables.
1595 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1598 * New 'z' formatter for printing and examining memory, this displays the
1599 value as hexadecimal zero padded on the left to the size of the type.
1601 * GDB can now use Windows x64 unwinding data.
1603 * The "set remotebaud" command has been replaced by "set serial baud".
1604 Similarly, "show remotebaud" has been replaced by "show serial baud".
1605 The "set remotebaud" and "show remotebaud" commands are still available
1606 to provide backward compatibility with older versions of GDB.
1608 *** Changes in GDB 7.6
1610 * Target record has been renamed to record-full.
1611 Record/replay is now enabled with the "record full" command.
1612 This also affects settings that are associated with full record/replay
1613 that have been moved from "set/show record" to "set/show record full":
1615 set|show record full insn-number-max
1616 set|show record full stop-at-limit
1617 set|show record full memory-query
1619 * A new record target "record-btrace" has been added. The new target
1620 uses hardware support to record the control-flow of a process. It
1621 does not support replaying the execution, but it implements the
1622 below new commands for investigating the recorded execution log.
1623 This new recording method can be enabled using:
1627 The "record-btrace" target is only available on Intel Atom processors
1628 and requires a Linux kernel 2.6.32 or later.
1630 * Two new commands have been added for record/replay to give information
1631 about the recorded execution without having to replay the execution.
1632 The commands are only supported by "record btrace".
1634 record instruction-history prints the execution history at
1635 instruction granularity
1637 record function-call-history prints the execution history at
1638 function granularity
1640 * New native configurations
1642 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1643 FreeBSD/powerpc powerpc*-*-freebsd
1644 x86_64/Cygwin x86_64-*-cygwin*
1645 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1649 ARM AArch64 aarch64*-*-elf
1650 ARM AArch64 GNU/Linux aarch64*-*-linux
1651 Lynx 178 PowerPC powerpc-*-lynx*178
1652 x86_64/Cygwin x86_64-*-cygwin*
1653 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1655 * If the configured location of system.gdbinit file (as given by the
1656 --with-system-gdbinit option at configure time) is in the
1657 data-directory (as specified by --with-gdb-datadir at configure
1658 time) or in one of its subdirectories, then GDB will look for the
1659 system-wide init file in the directory specified by the
1660 --data-directory command-line option.
1662 * New command line options:
1664 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1665 other initialization files, unlike -nx which disables all of them.
1667 * Removed command line options
1669 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1672 * The 'ptype' and 'whatis' commands now accept an argument to control
1675 * 'info proc' now works on some core files.
1679 ** Vectors can be created with gdb.Type.vector.
1681 ** Python's atexit.register now works in GDB.
1683 ** Types can be pretty-printed via a Python API.
1685 ** Python 3 is now supported (in addition to Python 2.4 or later)
1687 ** New class gdb.Architecture exposes GDB's internal representation
1688 of architecture in the Python API.
1690 ** New method Frame.architecture returns the gdb.Architecture object
1691 corresponding to the frame's architecture.
1693 * New Python-based convenience functions:
1695 ** $_memeq(buf1, buf2, length)
1696 ** $_streq(str1, str2)
1698 ** $_regex(str, regex)
1700 * The 'cd' command now defaults to using '~' (the home directory) if not
1703 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1704 default for GCC since November 2000.
1706 * The command 'forward-search' can now be abbreviated as 'fo'.
1708 * The command 'info tracepoints' can now display 'installed on target'
1709 or 'not installed on target' for each non-pending location of tracepoint.
1711 * New configure options
1713 --enable-libmcheck/--disable-libmcheck
1714 By default, development versions are built with -lmcheck on hosts
1715 that support it, in order to help track memory corruption issues.
1716 Release versions, on the other hand, are built without -lmcheck
1717 by default. The --enable-libmcheck/--disable-libmcheck configure
1718 options allow the user to override that default.
1719 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1720 This configure option allows the user to build GDB with
1721 libbabeltrace using which GDB can read Common Trace Format data.
1723 * New commands (for set/show, see "New options" below)
1726 Catch signals. This is similar to "handle", but allows commands and
1727 conditions to be attached.
1730 List the BFDs known to GDB.
1732 python-interactive [command]
1734 Start a Python interactive prompt, or evaluate the optional command
1735 and print the result of expressions.
1738 "py" is a new alias for "python".
1740 enable type-printer [name]...
1741 disable type-printer [name]...
1742 Enable or disable type printers.
1746 ** For the Renesas Super-H architecture, the "regs" command has been removed
1747 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1752 set print type methods (on|off)
1753 show print type methods
1754 Control whether method declarations are displayed by "ptype".
1755 The default is to show them.
1757 set print type typedefs (on|off)
1758 show print type typedefs
1759 Control whether typedef definitions are displayed by "ptype".
1760 The default is to show them.
1762 set filename-display basename|relative|absolute
1763 show filename-display
1764 Control the way in which filenames is displayed.
1765 The default is "relative", which preserves previous behavior.
1767 set trace-buffer-size
1768 show trace-buffer-size
1769 Request target to change the size of trace buffer.
1771 set remote trace-buffer-size-packet auto|on|off
1772 show remote trace-buffer-size-packet
1773 Control the use of the remote protocol `QTBuffer:size' packet.
1777 Control display of debugging messages related to ARM AArch64.
1780 set debug coff-pe-read
1781 show debug coff-pe-read
1782 Control display of debugging messages related to reading of COFF/PE
1787 Control display of debugging messages related to Mach-O symbols
1790 set debug notification
1791 show debug notification
1792 Control display of debugging info for async remote notification.
1796 ** Command parameter changes are now notified using new async record
1797 "=cmd-param-changed".
1798 ** Trace frame changes caused by command "tfind" are now notified using
1799 new async record "=traceframe-changed".
1800 ** The creation, deletion and modification of trace state variables
1801 are now notified using new async records "=tsv-created",
1802 "=tsv-deleted" and "=tsv-modified".
1803 ** The start and stop of process record are now notified using new
1804 async record "=record-started" and "=record-stopped".
1805 ** Memory changes are now notified using new async record
1807 ** The data-disassemble command response will include a "fullname" field
1808 containing the absolute file name when source has been requested.
1809 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1810 command, to allow pattern filling of memory areas.
1811 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1812 library load/unload events.
1813 ** The response to breakpoint commands and breakpoint async records
1814 includes an "installed" field containing a boolean state about each
1815 non-pending tracepoint location is whether installed on target or not.
1816 ** Output of the "-trace-status" command includes a "trace-file" field
1817 containing the name of the trace file being examined. This field is
1818 optional, and only present when examining a trace file.
1819 ** The "fullname" field is now always present along with the "file" field,
1820 even if the file cannot be found by GDB.
1822 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1823 You must have the LZMA library available when configuring GDB for this
1824 feature to be enabled. For more information, see:
1825 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1827 * New remote packets
1830 Set the size of trace buffer. The remote stub reports support for this
1831 packet to gdb's qSupported query.
1834 Enable Branch Trace Store (BTS)-based branch tracing for the current
1835 thread. The remote stub reports support for this packet to gdb's
1839 Disable branch tracing for the current thread. The remote stub reports
1840 support for this packet to gdb's qSupported query.
1843 Read the traced branches for the current thread. The remote stub
1844 reports support for this packet to gdb's qSupported query.
1846 *** Changes in GDB 7.5
1848 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1849 for more x32 ABI info.
1851 * GDB now supports access to MIPS DSP registers on Linux targets.
1853 * GDB now supports debugging microMIPS binaries.
1855 * The "info os" command on GNU/Linux can now display information on
1856 several new classes of objects managed by the operating system:
1857 "info os procgroups" lists process groups
1858 "info os files" lists file descriptors
1859 "info os sockets" lists internet-domain sockets
1860 "info os shm" lists shared-memory regions
1861 "info os semaphores" lists semaphores
1862 "info os msg" lists message queues
1863 "info os modules" lists loaded kernel modules
1865 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1866 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1867 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1868 options and inspect the probe arguments using the new $_probe_arg family
1869 of convenience variables. You can obtain more information about SystemTap
1870 in <http://sourceware.org/systemtap/>.
1872 * GDB now supports reversible debugging on ARM, it allows you to
1873 debug basic ARM and THUMB instructions, and provides
1874 record/replay support.
1876 * The option "symbol-reloading" has been deleted as it is no longer used.
1880 ** GDB commands implemented in Python can now be put in command class
1883 ** The "maint set python print-stack on|off" is now deleted.
1885 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1886 apply "flag enum"-style pretty-printing to any enum.
1888 ** gdb.lookup_symbol can now work when there is no current frame.
1890 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1891 the source at which the symbol was defined.
1893 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1894 method 'value'. The former indicates whether the symbol needs a
1895 frame in order to compute its value, and the latter computes the
1898 ** A new method 'referenced_value' on gdb.Value objects which can
1899 dereference pointer as well as C++ reference values.
1901 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1902 which return the global and static blocks (as gdb.Block objects),
1903 of the underlying symbol table, respectively.
1905 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1906 object associated with a PC value.
1908 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1909 of the address range occupied by code for the current source line.
1911 * Go language support.
1912 GDB now supports debugging programs written in the Go programming
1915 * GDBserver now supports stdio connections.
1916 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1918 * The binary "gdbtui" can no longer be built or installed.
1919 Use "gdb -tui" instead.
1921 * GDB will now print "flag" enums specially. A flag enum is one where
1922 all the enumerator values have no bits in common when pairwise
1923 "and"ed. When printing a value whose type is a flag enum, GDB will
1924 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1925 (gdb) print (enum E) 3
1928 * The filename part of a linespec will now match trailing components
1929 of a source file name. For example, "break gcc/expr.c:1000" will
1930 now set a breakpoint in build/gcc/expr.c, but not
1931 build/libcpp/expr.c.
1933 * The "info proc" and "generate-core-file" commands will now also
1934 work on remote targets connected to GDBserver on Linux.
1936 * The command "info catch" has been removed. It has been disabled
1937 since December 2007.
1939 * The "catch exception" and "catch assert" commands now accept
1940 a condition at the end of the command, much like the "break"
1941 command does. For instance:
1943 (gdb) catch exception Constraint_Error if Barrier = True
1945 Previously, it was possible to add a condition to such catchpoints,
1946 but it had to be done as a second step, after the catchpoint had been
1947 created, using the "condition" command.
1949 * The "info static-tracepoint-marker" command will now also work on
1950 native Linux targets with in-process agent.
1952 * GDB can now set breakpoints on inlined functions.
1954 * The .gdb_index section has been updated to include symbols for
1955 inlined functions. GDB will ignore older .gdb_index sections by
1956 default, which could cause symbol files to be loaded more slowly
1957 until their .gdb_index sections can be recreated. The new command
1958 "set use-deprecated-index-sections on" will cause GDB to use any older
1959 .gdb_index sections it finds. This will restore performance, but the
1960 ability to set breakpoints on inlined functions will be lost in symbol
1961 files with older .gdb_index sections.
1963 The .gdb_index section has also been updated to record more information
1964 about each symbol. This speeds up the "info variables", "info functions"
1965 and "info types" commands when used with programs having the .gdb_index
1966 section, as well as speeding up debugging with shared libraries using
1967 the .gdb_index section.
1969 * Ada support for GDB/MI Variable Objects has been added.
1971 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1976 ** New command -info-os is the MI equivalent of "info os".
1978 ** Output logs ("set logging" and related) now include MI output.
1982 ** "set use-deprecated-index-sections on|off"
1983 "show use-deprecated-index-sections on|off"
1984 Controls the use of deprecated .gdb_index sections.
1986 ** "catch load" and "catch unload" can be used to stop when a shared
1987 library is loaded or unloaded, respectively.
1989 ** "enable count" can be used to auto-disable a breakpoint after
1992 ** "info vtbl" can be used to show the virtual method tables for
1993 C++ and Java objects.
1995 ** "explore" and its sub commands "explore value" and "explore type"
1996 can be used to recursively explore values and types of
1997 expressions. These commands are available only if GDB is
1998 configured with '--with-python'.
2000 ** "info auto-load" shows status of all kinds of auto-loaded files,
2001 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2002 sequences of commands files, "info auto-load python-scripts"
2003 shows status of auto-loading Python script files,
2004 "info auto-load local-gdbinit" shows status of loading init file
2005 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2006 status of inferior specific thread debugging shared library loading.
2008 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2009 and "show auto-load-scripts" commands have been deprecated, use their
2010 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2011 and "show auto-load python-scripts" counterparts instead.
2013 ** "dprintf location,format,args..." creates a dynamic printf, which
2014 is basically a breakpoint that does a printf and immediately
2015 resumes your program's execution, so it is like a printf that you
2016 can insert dynamically at runtime instead of at compiletime.
2018 ** "set print symbol"
2020 Controls whether GDB attempts to display the symbol, if any,
2021 corresponding to addresses it prints. This defaults to "on", but
2022 you can set it to "off" to restore GDB's previous behavior.
2024 * Deprecated commands
2026 ** For the Renesas Super-H architecture, the "regs" command has been
2027 deprecated, and "info all-registers" should be used instead.
2031 Renesas RL78 rl78-*-elf
2032 HP OpenVMS ia64 ia64-hp-openvms*
2034 * GDBserver supports evaluation of breakpoint conditions. When
2035 support is advertised by GDBserver, GDB may be told to send the
2036 breakpoint conditions in bytecode form to GDBserver. GDBserver
2037 will only report the breakpoint trigger to GDB when its condition
2042 set mips compression
2043 show mips compression
2044 Select the compressed ISA encoding used in functions that have no symbol
2045 information available. The encoding can be set to either of:
2048 and is updated automatically from ELF file flags if available.
2050 set breakpoint condition-evaluation
2051 show breakpoint condition-evaluation
2052 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2053 GDBserver ("target"). Default option "auto" chooses the most efficient
2055 This option can improve debugger efficiency depending on the speed of the
2059 Disable auto-loading globally.
2062 Show auto-loading setting of all kinds of auto-loaded files.
2064 set auto-load gdb-scripts on|off
2065 show auto-load gdb-scripts
2066 Control auto-loading of GDB canned sequences of commands files.
2068 set auto-load python-scripts on|off
2069 show auto-load python-scripts
2070 Control auto-loading of Python script files.
2072 set auto-load local-gdbinit on|off
2073 show auto-load local-gdbinit
2074 Control loading of init file (.gdbinit) from current directory.
2076 set auto-load libthread-db on|off
2077 show auto-load libthread-db
2078 Control auto-loading of inferior specific thread debugging shared library.
2080 set auto-load scripts-directory <dir1>[:<dir2>...]
2081 show auto-load scripts-directory
2082 Set a list of directories from which to load auto-loaded scripts.
2083 Automatically loaded Python scripts and GDB scripts are located in one
2084 of the directories listed by this option.
2085 The delimiter (':' above) may differ according to the host platform.
2087 set auto-load safe-path <dir1>[:<dir2>...]
2088 show auto-load safe-path
2089 Set a list of directories from which it is safe to auto-load files.
2090 The delimiter (':' above) may differ according to the host platform.
2092 set debug auto-load on|off
2093 show debug auto-load
2094 Control display of debugging info for auto-loading the files above.
2096 set dprintf-style gdb|call|agent
2098 Control the way in which a dynamic printf is performed; "gdb"
2099 requests a GDB printf command, while "call" causes dprintf to call a
2100 function in the inferior. "agent" requests that the target agent
2101 (such as GDBserver) do the printing.
2103 set dprintf-function <expr>
2104 show dprintf-function
2105 set dprintf-channel <expr>
2106 show dprintf-channel
2107 Set the function and optional first argument to the call when using
2108 the "call" style of dynamic printf.
2110 set disconnected-dprintf on|off
2111 show disconnected-dprintf
2112 Control whether agent-style dynamic printfs continue to be in effect
2113 after GDB disconnects.
2115 * New configure options
2117 --with-auto-load-dir
2118 Configure default value for the 'set auto-load scripts-directory'
2119 setting above. It defaults to '$debugdir:$datadir/auto-load',
2120 $debugdir representing global debugging info directories (available
2121 via 'show debug-file-directory') and $datadir representing GDB's data
2122 directory (available via 'show data-directory').
2124 --with-auto-load-safe-path
2125 Configure default value for the 'set auto-load safe-path' setting
2126 above. It defaults to the --with-auto-load-dir setting.
2128 --without-auto-load-safe-path
2129 Set 'set auto-load safe-path' to '/', effectively disabling this
2132 * New remote packets
2134 z0/z1 conditional breakpoints extension
2136 The z0/z1 breakpoint insertion packets have been extended to carry
2137 a list of conditional expressions over to the remote stub depending on the
2138 condition evaluation mode. The use of this extension can be controlled
2139 via the "set remote conditional-breakpoints-packet" command.
2143 Specify the signals which the remote stub may pass to the debugged
2144 program without GDB involvement.
2146 * New command line options
2148 --init-command=FILE, -ix Like --command, -x but execute it
2149 before loading inferior.
2150 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2151 execute it before loading inferior.
2153 *** Changes in GDB 7.4
2155 * GDB now handles ambiguous linespecs more consistently; the existing
2156 FILE:LINE support has been expanded to other types of linespecs. A
2157 breakpoint will now be set on all matching locations in all
2158 inferiors, and locations will be added or removed according to
2161 * GDB now allows you to skip uninteresting functions and files when
2162 stepping with the "skip function" and "skip file" commands.
2164 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2165 and "show remote hardware-watchpoint-length-limit". These allows to
2166 set or show the maximum length limit (in bytes) of a remote
2167 target hardware watchpoint.
2169 This allows e.g. to use "unlimited" hardware watchpoints with the
2170 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2171 watchpoints are slower than real hardware watchpoints but are
2172 significantly faster than gdb software watchpoints.
2176 ** The register_pretty_printer function in module gdb.printing now takes
2177 an optional `replace' argument. If True, the new printer replaces any
2180 ** The "maint set python print-stack on|off" command has been
2181 deprecated and will be deleted in GDB 7.5.
2182 A new command: "set python print-stack none|full|message" has
2183 replaced it. Additionally, the default for "print-stack" is
2184 now "message", which just prints the error message without
2187 ** A prompt substitution hook (prompt_hook) is now available to the
2190 ** A new Python module, gdb.prompt has been added to the GDB Python
2191 modules library. This module provides functionality for
2192 escape sequences in prompts (used by set/show
2193 extended-prompt). These escape sequences are replaced by their
2194 corresponding value.
2196 ** Python commands and convenience-functions located in
2197 'data-directory'/python/gdb/command and
2198 'data-directory'/python/gdb/function are now automatically loaded
2201 ** Blocks now provide four new attributes. global_block and
2202 static_block will return the global and static blocks
2203 respectively. is_static and is_global are boolean attributes
2204 that indicate if the block is one of those two types.
2206 ** Symbols now provide the "type" attribute, the type of the symbol.
2208 ** The "gdb.breakpoint" function has been deprecated in favor of
2211 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2212 of a function. This class is based on the "finish" command
2213 available in the CLI.
2215 ** Type objects for struct and union types now allow access to
2216 the fields using standard Python dictionary (mapping) methods.
2217 For example, "some_type['myfield']" now works, as does
2218 "some_type.items()".
2220 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2223 ** A new function, "deep_items" has been added to the gdb.types
2224 module in the GDB Python modules library. This function returns
2225 an iterator over the fields of a struct or union type. Unlike
2226 the standard Python "iteritems" method, it will recursively traverse
2227 any anonymous fields.
2231 ** "*stopped" events can report several new "reason"s, such as
2234 ** Breakpoint changes are now notified using new async records, like
2235 "=breakpoint-modified".
2237 ** New command -ada-task-info.
2239 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2240 $sdir specifies the default system locations of shared libraries.
2241 $pdir specifies the directory where the libpthread used by the application
2244 GDB no longer looks in $sdir and $pdir after it has searched the directories
2245 mentioned in libthread-db-search-path. If you want to search those
2246 directories, they must be specified in libthread-db-search-path.
2247 The default value of libthread-db-search-path on GNU/Linux and Solaris
2248 systems is now "$sdir:$pdir".
2250 $pdir is not supported by gdbserver, it is currently ignored.
2251 $sdir is supported by gdbserver.
2253 * New configure option --with-iconv-bin.
2254 When using the internationalization support like the one in the GNU C
2255 library, GDB will invoke the "iconv" program to get a list of supported
2256 character sets. If this program lives in a non-standard location, one can
2257 use this option to specify where to find it.
2259 * When natively debugging programs on PowerPC BookE processors running
2260 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2261 watchpoints, which specify a mask in addition to an address to watch.
2262 The mask specifies that some bits of an address (the bits which are
2263 reset in the mask) should be ignored when matching the address accessed
2264 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2265 section in the user manual for more details.
2267 * The new option --once causes GDBserver to stop listening for connections once
2268 the first connection is made. The listening port used by GDBserver will
2269 become available after that.
2271 * New commands "info macros" and "alias" have been added.
2273 * New function parameters suffix @entry specifies value of function parameter
2274 at the time the function got called. Entry values are available only since
2280 "!" is now an alias of the "shell" command.
2281 Note that no space is needed between "!" and SHELL COMMAND.
2285 watch EXPRESSION mask MASK_VALUE
2286 The watch command now supports the mask argument which allows creation
2287 of masked watchpoints, if the current architecture supports this feature.
2289 info auto-load-scripts [REGEXP]
2290 This command was formerly named "maintenance print section-scripts".
2291 It is now generally useful and is no longer a maintenance-only command.
2293 info macro [-all] [--] MACRO
2294 The info macro command has new options `-all' and `--'. The first for
2295 printing all definitions of a macro. The second for explicitly specifying
2296 the end of arguments and the beginning of the macro name in case the macro
2297 name starts with a hyphen.
2299 collect[/s] EXPRESSIONS
2300 The tracepoint collect command now takes an optional modifier "/s"
2301 that directs it to dereference pointer-to-character types and
2302 collect the bytes of memory up to a zero byte. The behavior is
2303 similar to what you see when you use the regular print command on a
2304 string. An optional integer following the "/s" sets a bound on the
2305 number of bytes that will be collected.
2308 The trace start command now interprets any supplied arguments as a
2309 note to be recorded with the trace run, with an effect similar to
2310 setting the variable trace-notes.
2313 The trace stop command now interprets any arguments as a note to be
2314 mentioned along with the tstatus report that the trace was stopped
2315 with a command. The effect is similar to setting the variable
2318 * Tracepoints can now be enabled and disabled at any time after a trace
2319 experiment has been started using the standard "enable" and "disable"
2320 commands. It is now possible to start a trace experiment with no enabled
2321 tracepoints; GDB will display a warning, but will allow the experiment to
2322 begin, assuming that tracepoints will be enabled as needed while the trace
2325 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2326 locations with 4-byte instructions, when they were previously
2327 limited to locations with instructions of 5 bytes or longer.
2331 set debug dwarf2-read
2332 show debug dwarf2-read
2333 Turns on or off display of debugging messages related to reading
2334 DWARF debug info. The default is off.
2336 set debug symtab-create
2337 show debug symtab-create
2338 Turns on or off display of debugging messages related to symbol table
2339 creation. The default is off.
2342 show extended-prompt
2343 Set the GDB prompt, and allow escape sequences to be inserted to
2344 display miscellaneous information (see 'help set extended-prompt'
2345 for the list of sequences). This prompt (and any information
2346 accessed through the escape sequences) is updated every time the
2347 prompt is displayed.
2349 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2350 show print entry-values
2351 Set printing of frame argument values at function entry. In some cases
2352 GDB can determine the value of function argument which was passed by the
2353 function caller, even if the value was modified inside the called function.
2355 set debug entry-values
2356 show debug entry-values
2357 Control display of debugging info for determining frame argument values at
2358 function entry and virtual tail call frames.
2360 set basenames-may-differ
2361 show basenames-may-differ
2362 Set whether a source file may have multiple base names.
2363 (A "base name" is the name of a file with the directory part removed.
2364 Example: The base name of "/home/user/hello.c" is "hello.c".)
2365 If set, GDB will canonicalize file names (e.g., expand symlinks)
2366 before comparing them. Canonicalization is an expensive operation,
2367 but it allows the same file be known by more than one base name.
2368 If not set (the default), all source files are assumed to have just
2369 one base name, and gdb will do file name comparisons more efficiently.
2375 Set a user name and notes for the current and any future trace runs.
2376 This is useful for long-running and/or disconnected traces, to
2377 inform others (or yourself) as to who is running the trace, supply
2378 contact information, or otherwise explain what is going on.
2380 set trace-stop-notes
2381 show trace-stop-notes
2382 Set a note attached to the trace run, that is displayed when the
2383 trace has been stopped by a tstop command. This is useful for
2384 instance as an explanation, if you are stopping a trace run that was
2385 started by someone else.
2387 * New remote packets
2391 Dynamically enable a tracepoint in a started trace experiment.
2395 Dynamically disable a tracepoint in a started trace experiment.
2399 Set the user and notes of the trace run.
2403 Query the current status of a tracepoint.
2407 Query the minimum length of instruction at which a fast tracepoint may
2410 * Dcache size (number of lines) and line-size are now runtime-configurable
2411 via "set dcache line" and "set dcache line-size" commands.
2415 Texas Instruments TMS320C6x tic6x-*-*
2419 Renesas RL78 rl78-*-elf
2421 *** Changes in GDB 7.3.1
2423 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2425 *** Changes in GDB 7.3
2427 * GDB has a new command: "thread find [REGEXP]".
2428 It finds the thread id whose name, target id, or thread extra info
2429 matches the given regular expression.
2431 * The "catch syscall" command now works on mips*-linux* targets.
2433 * The -data-disassemble MI command now supports modes 2 and 3 for
2434 dumping the instruction opcodes.
2436 * New command line options
2438 -data-directory DIR Specify DIR as the "data-directory".
2439 This is mostly for testing purposes.
2441 * The "maint set python auto-load on|off" command has been renamed to
2442 "set auto-load-scripts on|off".
2444 * GDB has a new command: "set directories".
2445 It is like the "dir" command except that it replaces the
2446 source path list instead of augmenting it.
2448 * GDB now understands thread names.
2450 On GNU/Linux, "info threads" will display the thread name as set by
2451 prctl or pthread_setname_np.
2453 There is also a new command, "thread name", which can be used to
2454 assign a name internally for GDB to display.
2457 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2458 has been integrated into GDB.
2462 ** The function gdb.Write now accepts an optional keyword 'stream'.
2463 This keyword, when provided, will direct the output to either
2464 stdout, stderr, or GDB's logging output.
2466 ** Parameters can now be be sub-classed in Python, and in particular
2467 you may implement the get_set_doc and get_show_doc functions.
2468 This improves how Parameter set/show documentation is processed
2469 and allows for more dynamic content.
2471 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2472 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2473 have an is_valid method.
2475 ** Breakpoints can now be sub-classed in Python, and in particular
2476 you may implement a 'stop' function that is executed each time
2477 the inferior reaches that breakpoint.
2479 ** New function gdb.lookup_global_symbol looks up a global symbol.
2481 ** GDB values in Python are now callable if the value represents a
2482 function. For example, if 'some_value' represents a function that
2483 takes two integer parameters and returns a value, you can call
2484 that function like so:
2486 result = some_value (10,20)
2488 ** Module gdb.types has been added.
2489 It contains a collection of utilities for working with gdb.Types objects:
2490 get_basic_type, has_field, make_enum_dict.
2492 ** Module gdb.printing has been added.
2493 It contains utilities for writing and registering pretty-printers.
2494 New classes: PrettyPrinter, SubPrettyPrinter,
2495 RegexpCollectionPrettyPrinter.
2496 New function: register_pretty_printer.
2498 ** New commands "info pretty-printers", "enable pretty-printer" and
2499 "disable pretty-printer" have been added.
2501 ** gdb.parameter("directories") is now available.
2503 ** New function gdb.newest_frame returns the newest frame in the
2506 ** The gdb.InferiorThread class has a new "name" attribute. This
2507 holds the thread's name.
2509 ** Python Support for Inferior events.
2510 Python scripts can add observers to be notified of events
2511 occurring in the process being debugged.
2512 The following events are currently supported:
2513 - gdb.events.cont Continue event.
2514 - gdb.events.exited Inferior exited event.
2515 - gdb.events.stop Signal received, and Breakpoint hit events.
2519 ** GDB now puts template parameters in scope when debugging in an
2520 instantiation. For example, if you have:
2522 template<int X> int func (void) { return X; }
2524 then if you step into func<5>, "print X" will show "5". This
2525 feature requires proper debuginfo support from the compiler; it
2526 was added to GCC 4.5.
2528 ** The motion commands "next", "finish", "until", and "advance" now
2529 work better when exceptions are thrown. In particular, GDB will
2530 no longer lose control of the inferior; instead, the GDB will
2531 stop the inferior at the point at which the exception is caught.
2532 This functionality requires a change in the exception handling
2533 code that was introduced in GCC 4.5.
2535 * GDB now follows GCC's rules on accessing volatile objects when
2536 reading or writing target state during expression evaluation.
2537 One notable difference to prior behavior is that "print x = 0"
2538 no longer generates a read of x; the value of the assignment is
2539 now always taken directly from the value being assigned.
2541 * GDB now has some support for using labels in the program's source in
2542 linespecs. For instance, you can use "advance label" to continue
2543 execution to a label.
2545 * GDB now has support for reading and writing a new .gdb_index
2546 section. This section holds a fast index of DWARF debugging
2547 information and can be used to greatly speed up GDB startup and
2548 operation. See the documentation for `save gdb-index' for details.
2550 * The "watch" command now accepts an optional "-location" argument.
2551 When used, this causes GDB to watch the memory referred to by the
2552 expression. Such a watchpoint is never deleted due to it going out
2555 * GDB now supports thread debugging of core dumps on GNU/Linux.
2557 GDB now activates thread debugging using the libthread_db library
2558 when debugging GNU/Linux core dumps, similarly to when debugging
2559 live processes. As a result, when debugging a core dump file, GDB
2560 is now able to display pthread_t ids of threads. For example, "info
2561 threads" shows the same output as when debugging the process when it
2562 was live. In earlier releases, you'd see something like this:
2565 * 1 LWP 6780 main () at main.c:10
2567 While now you see this:
2570 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2572 It is also now possible to inspect TLS variables when debugging core
2575 When debugging a core dump generated on a machine other than the one
2576 used to run GDB, you may need to point GDB at the correct
2577 libthread_db library with the "set libthread-db-search-path"
2578 command. See the user manual for more details on this command.
2580 * When natively debugging programs on PowerPC BookE processors running
2581 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2582 which stop execution of the inferior whenever it executes an instruction
2583 at any address within the specified range. See the "PowerPC Embedded"
2584 section in the user manual for more details.
2586 * New features in the GDB remote stub, GDBserver
2588 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2589 and i686 LynxOS (version 5.x).
2591 ** GDBserver is now supported on Blackfin Linux.
2593 * New native configurations
2595 ia64 HP-UX ia64-*-hpux*
2599 Analog Devices, Inc. Blackfin Processor bfin-*
2601 * Ada task switching is now supported on sparc-elf targets when
2602 debugging a program using the Ravenscar Profile. For more information,
2603 see the "Tasking Support when using the Ravenscar Profile" section
2604 in the GDB user manual.
2606 * Guile support was removed.
2608 * New features in the GNU simulator
2610 ** The --map-info flag lists all known core mappings.
2612 ** CFI flashes may be simulated via the "cfi" device.
2614 *** Changes in GDB 7.2
2616 * Shared library support for remote targets by default
2618 When GDB is configured for a generic, non-OS specific target, like
2619 for example, --target=arm-eabi or one of the many *-*-elf targets,
2620 GDB now queries remote stubs for loaded shared libraries using the
2621 `qXfer:libraries:read' packet. Previously, shared library support
2622 was always disabled for such configurations.
2626 ** Argument Dependent Lookup (ADL)
2628 In C++ ADL lookup directs function search to the namespaces of its
2629 arguments even if the namespace has not been imported.
2639 Here the compiler will search for `foo' in the namespace of 'b'
2640 and find A::foo. GDB now supports this. This construct is commonly
2641 used in the Standard Template Library for operators.
2643 ** Improved User Defined Operator Support
2645 In addition to member operators, GDB now supports lookup of operators
2646 defined in a namespace and imported with a `using' directive, operators
2647 defined in the global scope, operators imported implicitly from an
2648 anonymous namespace, and the ADL operators mentioned in the previous
2650 GDB now also supports proper overload resolution for all the previously
2651 mentioned flavors of operators.
2653 ** static const class members
2655 Printing of static const class members that are initialized in the
2656 class definition has been fixed.
2658 * Windows Thread Information Block access.
2660 On Windows targets, GDB now supports displaying the Windows Thread
2661 Information Block (TIB) structure. This structure is visible either
2662 by using the new command `info w32 thread-information-block' or, by
2663 dereferencing the new convenience variable named `$_tlb', a
2664 thread-specific pointer to the TIB. This feature is also supported
2665 when remote debugging using GDBserver.
2667 * Static tracepoints
2669 Static tracepoints are calls in the user program into a tracing
2670 library. One such library is a port of the LTTng kernel tracer to
2671 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2672 When debugging with GDBserver, GDB now supports combining the GDB
2673 tracepoint machinery with such libraries. For example: the user can
2674 use GDB to probe a static tracepoint marker (a call from the user
2675 program into the tracing library) with the new "strace" command (see
2676 "New commands" below). This creates a "static tracepoint" in the
2677 breakpoint list, that can be manipulated with the same feature set
2678 as fast and regular tracepoints. E.g., collect registers, local and
2679 global variables, collect trace state variables, and define
2680 tracepoint conditions. In addition, the user can collect extra
2681 static tracepoint marker specific data, by collecting the new
2682 $_sdata internal variable. When analyzing the trace buffer, you can
2683 inspect $_sdata like any other variable available to GDB. For more
2684 information, see the "Tracepoints" chapter in GDB user manual. New
2685 remote packets have been defined to support static tracepoints, see
2686 the "New remote packets" section below.
2688 * Better reconstruction of tracepoints after disconnected tracing
2690 GDB will attempt to download the original source form of tracepoint
2691 definitions when starting a trace run, and then will upload these
2692 upon reconnection to the target, resulting in a more accurate
2693 reconstruction of the tracepoints that are in use on the target.
2697 You can now exercise direct control over the ways that GDB can
2698 affect your program. For instance, you can disallow the setting of
2699 breakpoints, so that the program can run continuously (assuming
2700 non-stop mode). In addition, the "observer" variable is available
2701 to switch all of the different controls; in observer mode, GDB
2702 cannot affect the target's behavior at all, which is useful for
2703 tasks like diagnosing live systems in the field.
2705 * The new convenience variable $_thread holds the number of the
2708 * New remote packets
2712 Return the address of the Windows Thread Information Block of a given thread.
2716 In response to several of the tracepoint packets, the target may now
2717 also respond with a number of intermediate `qRelocInsn' request
2718 packets before the final result packet, to have GDB handle
2719 relocating an instruction to execute at a different address. This
2720 is particularly useful for stubs that support fast tracepoints. GDB
2721 reports support for this feature in the qSupported packet.
2725 List static tracepoint markers in the target program.
2729 List static tracepoint markers at a given address in the target
2732 qXfer:statictrace:read
2734 Read the static trace data collected (by a `collect $_sdata'
2735 tracepoint action). The remote stub reports support for this packet
2736 to gdb's qSupported query.
2740 Send the current settings of GDB's permission flags.
2744 Send part of the source (textual) form of a tracepoint definition,
2745 which includes location, conditional, and action list.
2747 * The source command now accepts a -s option to force searching for the
2748 script in the source search path even if the script name specifies
2751 * New features in the GDB remote stub, GDBserver
2753 - GDBserver now support tracepoints (including fast tracepoints, and
2754 static tracepoints). The feature is currently supported by the
2755 i386-linux and amd64-linux builds. See the "Tracepoints support
2756 in gdbserver" section in the manual for more information.
2758 GDBserver JIT compiles the tracepoint's conditional agent
2759 expression bytecode into native code whenever possible for low
2760 overhead dynamic tracepoints conditionals. For such tracepoints,
2761 an expression that examines program state is evaluated when the
2762 tracepoint is reached, in order to determine whether to capture
2763 trace data. If the condition is simple and false, processing the
2764 tracepoint finishes very quickly and no data is gathered.
2766 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2767 for static tracepoints support.
2769 - GDBserver now supports x86_64 Windows 64-bit debugging.
2771 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2772 it understands register description.
2774 * The --batch flag now disables pagination and queries.
2776 * X86 general purpose registers
2778 GDB now supports reading/writing byte, word and double-word x86
2779 general purpose registers directly. This means you can use, say,
2780 $ah or $ax to refer, respectively, to the byte register AH and
2781 16-bit word register AX that are actually portions of the 32-bit
2782 register EAX or 64-bit register RAX.
2784 * The `commands' command now accepts a range of breakpoints to modify.
2785 A plain `commands' following a command that creates multiple
2786 breakpoints affects all the breakpoints set by that command. This
2787 applies to breakpoints set by `rbreak', and also applies when a
2788 single `break' command creates multiple breakpoints (e.g.,
2789 breakpoints on overloaded c++ functions).
2791 * The `rbreak' command now accepts a filename specification as part of
2792 its argument, limiting the functions selected by the regex to those
2793 in the specified file.
2795 * Support for remote debugging Windows and SymbianOS shared libraries
2796 from Unix hosts has been improved. Non Windows GDB builds now can
2797 understand target reported file names that follow MS-DOS based file
2798 system semantics, such as file names that include drive letters and
2799 use the backslash character as directory separator. This makes it
2800 possible to transparently use the "set sysroot" and "set
2801 solib-search-path" on Unix hosts to point as host copies of the
2802 target's shared libraries. See the new command "set
2803 target-file-system-kind" described below, and the "Commands to
2804 specify files" section in the user manual for more information.
2808 eval template, expressions...
2809 Convert the values of one or more expressions under the control
2810 of the string template to a command line, and call it.
2812 set target-file-system-kind unix|dos-based|auto
2813 show target-file-system-kind
2814 Set or show the assumed file system kind for target reported file
2817 save breakpoints <filename>
2818 Save all current breakpoint definitions to a file suitable for use
2819 in a later debugging session. To read the saved breakpoint
2820 definitions, use the `source' command.
2822 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2825 info static-tracepoint-markers
2826 Display information about static tracepoint markers in the target.
2828 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2829 Define a static tracepoint by probing a marker at the given
2830 function, line, address, or marker ID.
2834 Enable and disable observer mode.
2836 set may-write-registers on|off
2837 set may-write-memory on|off
2838 set may-insert-breakpoints on|off
2839 set may-insert-tracepoints on|off
2840 set may-insert-fast-tracepoints on|off
2841 set may-interrupt on|off
2842 Set individual permissions for GDB effects on the target. Note that
2843 some of these settings can have undesirable or surprising
2844 consequences, particularly when changed in the middle of a session.
2845 For instance, disabling the writing of memory can prevent
2846 breakpoints from being inserted, cause single-stepping to fail, or
2847 even crash your program, if you disable after breakpoints have been
2848 inserted. However, GDB should not crash.
2850 set record memory-query on|off
2851 show record memory-query
2852 Control whether to stop the inferior if memory changes caused
2853 by an instruction cannot be recorded.
2858 The disassemble command now supports "start,+length" form of two arguments.
2862 ** GDB now provides a new directory location, called the python directory,
2863 where Python scripts written for GDB can be installed. The location
2864 of that directory is <data-directory>/python, where <data-directory>
2865 is the GDB data directory. For more details, see section `Scripting
2866 GDB using Python' in the manual.
2868 ** The GDB Python API now has access to breakpoints, symbols, symbol
2869 tables, program spaces, inferiors, threads and frame's code blocks.
2870 Additionally, GDB Parameters can now be created from the API, and
2871 manipulated via set/show in the CLI.
2873 ** New functions gdb.target_charset, gdb.target_wide_charset,
2874 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2876 ** New exception gdb.GdbError.
2878 ** Pretty-printers are now also looked up in the current program space.
2880 ** Pretty-printers can now be individually enabled and disabled.
2882 ** GDB now looks for names of Python scripts to auto-load in a
2883 special section named `.debug_gdb_scripts', in addition to looking
2884 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2886 * Tracepoint actions were unified with breakpoint commands. In particular,
2887 there are no longer differences in "info break" output for breakpoints and
2888 tracepoints and the "commands" command can be used for both tracepoints and
2889 regular breakpoints.
2893 ARM Symbian arm*-*-symbianelf*
2895 * D language support.
2896 GDB now supports debugging programs written in the D programming
2899 * GDB now supports the extended ptrace interface for PowerPC which is
2900 available since Linux kernel version 2.6.34. This automatically enables
2901 any hardware breakpoints and additional hardware watchpoints available in
2902 the processor. The old ptrace interface exposes just one hardware
2903 watchpoint and no hardware breakpoints.
2905 * GDB is now able to use the Data Value Compare (DVC) register available on
2906 embedded PowerPC processors to implement in hardware simple watchpoint
2907 conditions of the form:
2909 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2911 This works in native GDB running on Linux kernels with the extended ptrace
2912 interface mentioned above.
2914 *** Changes in GDB 7.1
2918 ** Namespace Support
2920 GDB now supports importing of namespaces in C++. This enables the
2921 user to inspect variables from imported namespaces. Support for
2922 namepace aliasing has also been added. So, if a namespace is
2923 aliased in the current scope (e.g. namepace C=A; ) the user can
2924 print variables using the alias (e.g. (gdb) print C::x).
2928 All known bugs relating to the printing of virtual base class were
2929 fixed. It is now possible to call overloaded static methods using a
2934 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2935 and reinterpret_cast<> are now handled by the C++ expression parser.
2939 Xilinx MicroBlaze microblaze-*-*
2944 Xilinx MicroBlaze microblaze
2947 * Multi-program debugging.
2949 GDB now has support for multi-program (a.k.a. multi-executable or
2950 multi-exec) debugging. This allows for debugging multiple inferiors
2951 simultaneously each running a different program under the same GDB
2952 session. See "Debugging Multiple Inferiors and Programs" in the
2953 manual for more information. This implied some user visible changes
2954 in the multi-inferior support. For example, "info inferiors" now
2955 lists inferiors that are not running yet or that have exited
2956 already. See also "New commands" and "New options" below.
2958 * New tracing features
2960 GDB's tracepoint facility now includes several new features:
2962 ** Trace state variables
2964 GDB tracepoints now include support for trace state variables, which
2965 are variables managed by the target agent during a tracing
2966 experiment. They are useful for tracepoints that trigger each
2967 other, so for instance one tracepoint can count hits in a variable,
2968 and then a second tracepoint has a condition that is true when the
2969 count reaches a particular value. Trace state variables share the
2970 $-syntax of GDB convenience variables, and can appear in both
2971 tracepoint actions and condition expressions. Use the "tvariable"
2972 command to create, and "info tvariables" to view; see "Trace State
2973 Variables" in the manual for more detail.
2977 GDB now includes an option for defining fast tracepoints, which
2978 targets may implement more efficiently, such as by installing a jump
2979 into the target agent rather than a trap instruction. The resulting
2980 speedup can be by two orders of magnitude or more, although the
2981 tradeoff is that some program locations on some target architectures
2982 might not allow fast tracepoint installation, for instance if the
2983 instruction to be replaced is shorter than the jump. To request a
2984 fast tracepoint, use the "ftrace" command, with syntax identical to
2985 the regular trace command.
2987 ** Disconnected tracing
2989 It is now possible to detach GDB from the target while it is running
2990 a trace experiment, then reconnect later to see how the experiment
2991 is going. In addition, a new variable disconnected-tracing lets you
2992 tell the target agent whether to continue running a trace if the
2993 connection is lost unexpectedly.
2997 GDB now has the ability to save the trace buffer into a file, and
2998 then use that file as a target, similarly to you can do with
2999 corefiles. You can select trace frames, print data that was
3000 collected in them, and use tstatus to display the state of the
3001 tracing run at the moment that it was saved. To create a trace
3002 file, use "tsave <filename>", and to use it, do "target tfile
3005 ** Circular trace buffer
3007 You can ask the target agent to handle the trace buffer as a
3008 circular buffer, discarding the oldest trace frames to make room for
3009 newer ones, by setting circular-trace-buffer to on. This feature may
3010 not be available for all target agents.
3015 The disassemble command, when invoked with two arguments, now requires
3016 the arguments to be comma-separated.
3019 The info variables command now displays variable definitions. Files
3020 which only declare a variable are not shown.
3023 The source command is now capable of sourcing Python scripts.
3024 This feature is dependent on the debugger being build with Python
3027 Related to this enhancement is also the introduction of a new command
3028 "set script-extension" (see below).
3030 * New commands (for set/show, see "New options" below)
3032 record save [<FILENAME>]
3033 Save a file (in core file format) containing the process record
3034 execution log for replay debugging at a later time.
3036 record restore <FILENAME>
3037 Restore the process record execution log that was saved at an
3038 earlier time, for replay debugging.
3040 add-inferior [-copies <N>] [-exec <FILENAME>]
3043 clone-inferior [-copies <N>] [ID]
3044 Make a new inferior ready to execute the same program another
3045 inferior has loaded.
3050 maint info program-spaces
3051 List the program spaces loaded into GDB.
3053 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3054 show remote interrupt-sequence
3055 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3056 as the sequence to the remote target in order to interrupt the execution.
3057 Ctrl-C is a default. Some system prefers BREAK which is high level of
3058 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3059 Magic SysRq g. It is BREAK signal and character 'g'.
3061 set remote interrupt-on-connect [on | off]
3062 show remote interrupt-on-connect
3063 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3064 remote target when gdb connects to it. This is needed when you debug
3067 set remotebreak [on | off]
3069 Deprecated. Use "set/show remote interrupt-sequence" instead.
3071 tvariable $NAME [ = EXP ]
3072 Create or modify a trace state variable.
3075 List trace state variables and their values.
3077 delete tvariable $NAME ...
3078 Delete one or more trace state variables.
3081 Evaluate the given expressions without collecting anything into the
3082 trace buffer. (Valid in tracepoint actions only.)
3084 ftrace FN / FILE:LINE / *ADDR
3085 Define a fast tracepoint at the given function, line, or address.
3087 * New expression syntax
3089 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3090 GDB now parses 0b101010 identically with 42.
3094 set follow-exec-mode new|same
3095 show follow-exec-mode
3096 Control whether GDB reuses the same inferior across an exec call or
3097 creates a new one. This is useful to be able to restart the old
3098 executable after the inferior having done an exec call.
3100 set default-collect EXPR, ...
3101 show default-collect
3102 Define a list of expressions to be collected at each tracepoint.
3103 This is a useful way to ensure essential items are not overlooked,
3104 such as registers or a critical global variable.
3106 set disconnected-tracing
3107 show disconnected-tracing
3108 If set to 1, the target is instructed to continue tracing if it
3109 loses its connection to GDB. If 0, the target is to stop tracing
3112 set circular-trace-buffer
3113 show circular-trace-buffer
3114 If set to on, the target is instructed to use a circular trace buffer
3115 and discard the oldest trace frames instead of stopping the trace due
3116 to a full trace buffer. If set to off, the trace stops when the buffer
3117 fills up. Some targets may not support this.
3119 set script-extension off|soft|strict
3120 show script-extension
3121 If set to "off", the debugger does not perform any script language
3122 recognition, and all sourced files are assumed to be GDB scripts.
3123 If set to "soft" (the default), files are sourced according to
3124 filename extension, falling back to GDB scripts if the first
3126 If set to "strict", files are sourced according to filename extension.
3128 set ada trust-PAD-over-XVS on|off
3129 show ada trust-PAD-over-XVS
3130 If off, activate a workaround against a bug in the debugging information
3131 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3132 the GCC sources for more information about the GNAT encoding and
3133 PAD types in particular). It is always safe to set this option to
3134 off, but this introduces a slight performance penalty. The default
3137 * Python API Improvements
3139 ** GDB provides the new class gdb.LazyString. This is useful in
3140 some pretty-printing cases. The new method gdb.Value.lazy_string
3141 provides a simple way to create objects of this type.
3143 ** The fields returned by gdb.Type.fields now have an
3144 `is_base_class' attribute.
3146 ** The new method gdb.Type.range returns the range of an array type.
3148 ** The new method gdb.parse_and_eval can be used to parse and
3149 evaluate an expression.
3151 * New remote packets
3154 Define a trace state variable.
3157 Get the current value of a trace state variable.
3160 Set desired tracing behavior upon disconnection.
3163 Set the trace buffer to be linear or circular.
3166 Get data about the tracepoints currently in use.
3170 Process record now works correctly with hardware watchpoints.
3172 Multiple bug fixes have been made to the mips-irix port, making it
3173 much more reliable. In particular:
3174 - Debugging threaded applications is now possible again. Previously,
3175 GDB would hang while starting the program, or while waiting for
3176 the program to stop at a breakpoint.
3177 - Attaching to a running process no longer hangs.
3178 - An error occurring while loading a core file has been fixed.
3179 - Changing the value of the PC register now works again. This fixes
3180 problems observed when using the "jump" command, or when calling
3181 a function from GDB, or even when assigning a new value to $pc.
3182 - With the "finish" and "return" commands, the return value for functions
3183 returning a small array is now correctly printed.
3184 - It is now possible to break on shared library code which gets executed
3185 during a shared library init phase (code executed while executing
3186 their .init section). Previously, the breakpoint would have no effect.
3187 - GDB is now able to backtrace through the signal handler for
3188 non-threaded programs.
3190 PIE (Position Independent Executable) programs debugging is now supported.
3191 This includes debugging execution of PIC (Position Independent Code) shared
3192 libraries although for that, it should be possible to run such libraries as an
3195 *** Changes in GDB 7.0
3197 * GDB now has an interface for JIT compilation. Applications that
3198 dynamically generate code can create symbol files in memory and register
3199 them with GDB. For users, the feature should work transparently, and
3200 for JIT developers, the interface is documented in the GDB manual in the
3201 "JIT Compilation Interface" chapter.
3203 * Tracepoints may now be conditional. The syntax is as for
3204 breakpoints; either an "if" clause appended to the "trace" command,
3205 or the "condition" command is available. GDB sends the condition to
3206 the target for evaluation using the same bytecode format as is used
3207 for tracepoint actions.
3209 * The disassemble command now supports: an optional /r modifier, print the
3210 raw instructions in hex as well as in symbolic form, and an optional /m
3211 modifier to print mixed source+assembly.
3213 * Process record and replay
3215 In a architecture environment that supports ``process record and
3216 replay'', ``process record and replay'' target can record a log of
3217 the process execution, and replay it with both forward and reverse
3220 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3221 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3222 set execution-direction {forward|reverse}, for targets that support
3225 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3226 feature is available with a native GDB running on kernel version
3229 * GDB now has support for multi-byte and wide character sets on the
3230 target. Strings whose character type is wchar_t, char16_t, or
3231 char32_t are now correctly printed. GDB supports wide- and unicode-
3232 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3233 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3234 `printf'. This feature requires iconv to work properly; if your
3235 system does not have a working iconv, GDB can use GNU libiconv. See
3236 the installation instructions for more information.
3238 * GDB now supports automatic retrieval of shared library files from
3239 remote targets. To use this feature, specify a system root that begins
3240 with the `remote:' prefix, either via the `set sysroot' command or via
3241 the `--with-sysroot' configure-time option.
3243 * "info sharedlibrary" now takes an optional regex of libraries to show,
3244 and it now reports if a shared library has no debugging information.
3246 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3247 now complete on file names.
3249 * When completing in expressions, gdb will attempt to limit
3250 completions to allowable structure or union fields, where appropriate.
3251 For instance, consider:
3253 # struct example { int f1; double f2; };
3254 # struct example variable;
3257 If the user types TAB at the end of this command line, the available
3258 completions will be "f1" and "f2".
3260 * Inlined functions are now supported. They show up in backtraces, and
3261 the "step", "next", and "finish" commands handle them automatically.
3263 * GDB now supports the token-splicing (##) and stringification (#)
3264 operators when expanding macros. It also supports variable-arity
3267 * GDB now supports inspecting extra signal information, exported by
3268 the new $_siginfo convenience variable. The feature is currently
3269 implemented on linux ARM, i386 and amd64.
3271 * GDB can now display the VFP floating point registers and NEON vector
3272 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3273 can provide these registers (requires Linux 2.6.30 or later). Remote
3274 and simulator targets may also provide them.
3276 * New remote packets
3279 Search memory for a sequence of bytes.
3282 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3283 operation over reliable transport links. Use of this packet is
3284 controlled by the `set remote noack-packet' command.
3287 Kill the process with the specified process ID. Use this in preference
3288 to `k' when multiprocess protocol extensions are supported.
3291 Obtains additional operating system information
3295 Read or write additional signal information.
3297 * Removed remote protocol undocumented extension
3299 An undocumented extension to the remote protocol's `S' stop reply
3300 packet that permited the stub to pass a process id was removed.
3301 Remote servers should use the `T' stop reply packet instead.
3303 * GDB now supports multiple function calling conventions according to the
3304 DWARF-2 DW_AT_calling_convention function attribute.
3306 * The SH target utilizes the aforementioned change to distinguish between gcc
3307 and Renesas calling convention. It also adds the new CLI commands
3308 `set/show sh calling-convention'.
3310 * GDB can now read compressed debug sections, as produced by GNU gold
3311 with the --compress-debug-sections=zlib flag.
3313 * 64-bit core files are now supported on AIX.
3315 * Thread switching is now supported on Tru64.
3317 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3318 which will be allocated using malloc later in program execution.
3320 * The qXfer:libraries:read remote procotol packet now allows passing a
3321 list of section offsets.
3323 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3324 conditions handling signals delivered during attach or thread creation
3325 have also been fixed.
3327 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3328 From the user's standpoint, all unqualified instances of True and False
3329 are treated as the standard definitions, regardless of context.
3331 * GDB now parses C++ symbol and type names more flexibly. For
3334 template<typename T> class C { };
3337 GDB will now correctly handle all of:
3339 ptype C<char const *>
3340 ptype C<char const*>
3341 ptype C<const char *>
3342 ptype C<const char*>
3344 * New features in the GDB remote stub, gdbserver
3346 - The "--wrapper" command-line argument tells gdbserver to use a
3347 wrapper program to launch programs for debugging.
3349 - On PowerPC and S/390 targets, it is now possible to use a single
3350 gdbserver executable to debug both 32-bit and 64-bit programs.
3351 (This requires gdbserver itself to be built as a 64-bit executable.)
3353 - gdbserver uses the new noack protocol mode for TCP connections to
3354 reduce communications latency, if also supported and enabled in GDB.
3356 - Support for the sparc64-linux-gnu target is now included in
3359 - The amd64-linux build of gdbserver now supports debugging both
3360 32-bit and 64-bit programs.
3362 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3363 now support hardware watchpoints, and will use them automatically
3368 GDB now has support for scripting using Python. Whether this is
3369 available is determined at configure time.
3371 New GDB commands can now be written in Python.
3373 * Ada tasking support
3375 Ada tasks can now be inspected in GDB. The following commands have
3379 Print the list of Ada tasks.
3381 Print detailed information about task number N.
3383 Print the task number of the current task.
3385 Switch the context of debugging to task number N.
3387 * Support for user-defined prefixed commands. The "define" command can
3388 add new commands to existing prefixes, e.g. "target".
3390 * Multi-inferior, multi-process debugging.
3392 GDB now has generalized support for multi-inferior debugging. See
3393 "Debugging Multiple Inferiors" in the manual for more information.
3394 Although availability still depends on target support, the command
3395 set is more uniform now. The GNU/Linux specific multi-forks support
3396 has been migrated to this new framework. This implied some user
3397 visible changes; see "New commands" and also "Removed commands"
3400 * Target descriptions can now describe the target OS ABI. See the
3401 "Target Description Format" section in the user manual for more
3404 * Target descriptions can now describe "compatible" architectures
3405 to indicate that the target can execute applications for a different
3406 architecture in addition to those for the main target architecture.
3407 See the "Target Description Format" section in the user manual for
3410 * Multi-architecture debugging.
3412 GDB now includes general supports for debugging applications on
3413 hybrid systems that use more than one single processor architecture
3414 at the same time. Each such hybrid architecture still requires
3415 specific support to be added. The only hybrid architecture supported
3416 in this version of GDB is the Cell Broadband Engine.
3418 * GDB now supports integrated debugging of Cell/B.E. applications that
3419 use both the PPU and SPU architectures. To enable support for hybrid
3420 Cell/B.E. debugging, you need to configure GDB to support both the
3421 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3422 --enable-targets configure option.
3424 * Non-stop mode debugging.
3426 For some targets, GDB now supports an optional mode of operation in
3427 which you can examine stopped threads while other threads continue
3428 to execute freely. This is referred to as non-stop mode, with the
3429 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3430 section in the user manual for more information.
3432 To be able to support remote non-stop debugging, a remote stub needs
3433 to implement the non-stop mode remote protocol extensions, as
3434 described in the "Remote Non-Stop" section of the user manual. The
3435 GDB remote stub, gdbserver, has been adjusted to support these
3436 extensions on linux targets.
3438 * New commands (for set/show, see "New options" below)
3440 catch syscall [NAME(S) | NUMBER(S)]
3441 Catch system calls. Arguments, which should be names of system
3442 calls or their numbers, mean catch only those syscalls. Without
3443 arguments, every syscall will be caught. When the inferior issues
3444 any of the specified syscalls, GDB will stop and announce the system
3445 call, both when it is called and when its call returns. This
3446 feature is currently available with a native GDB running on the
3447 Linux Kernel, under the following architectures: x86, x86_64,
3448 PowerPC and PowerPC64.
3450 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3452 Search memory for a sequence of bytes.
3454 maint set python print-stack
3455 maint show python print-stack
3456 Show a stack trace when an error is encountered in a Python script.
3459 Invoke CODE by passing it to the Python interpreter.
3464 These allow macros to be defined, undefined, and listed
3468 Show operating system information about processes.
3471 List the inferiors currently under GDB's control.
3474 Switch focus to inferior number NUM.
3477 Detach from inferior number NUM.
3480 Kill inferior number NUM.
3484 set spu stop-on-load
3485 show spu stop-on-load
3486 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3488 set spu auto-flush-cache
3489 show spu auto-flush-cache
3490 Control whether to automatically flush the software-managed cache
3491 during Cell/B.E. debugging.
3493 set sh calling-convention
3494 show sh calling-convention
3495 Control the calling convention used when calling SH target functions.
3498 show debug timestamp
3499 Control display of timestamps with GDB debugging output.
3501 set disassemble-next-line
3502 show disassemble-next-line
3503 Control display of disassembled source lines or instructions when
3506 set remote noack-packet
3507 show remote noack-packet
3508 Set/show the use of remote protocol QStartNoAckMode packet. See above
3509 under "New remote packets."
3511 set remote query-attached-packet
3512 show remote query-attached-packet
3513 Control use of remote protocol `qAttached' (query-attached) packet.
3515 set remote read-siginfo-object
3516 show remote read-siginfo-object
3517 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3520 set remote write-siginfo-object
3521 show remote write-siginfo-object
3522 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3525 set remote reverse-continue
3526 show remote reverse-continue
3527 Control use of remote protocol 'bc' (reverse-continue) packet.
3529 set remote reverse-step
3530 show remote reverse-step
3531 Control use of remote protocol 'bs' (reverse-step) packet.
3533 set displaced-stepping
3534 show displaced-stepping
3535 Control displaced stepping mode. Displaced stepping is a way to
3536 single-step over breakpoints without removing them from the debuggee.
3537 Also known as "out-of-line single-stepping".
3540 show debug displaced
3541 Control display of debugging info for displaced stepping.
3543 maint set internal-error
3544 maint show internal-error
3545 Control what GDB does when an internal error is detected.
3547 maint set internal-warning
3548 maint show internal-warning
3549 Control what GDB does when an internal warning is detected.
3554 Use a wrapper program to launch programs for debugging.
3556 set multiple-symbols (all|ask|cancel)
3557 show multiple-symbols
3558 The value of this variable can be changed to adjust the debugger behavior
3559 when an expression or a breakpoint location contains an ambiguous symbol
3560 name (an overloaded function name, for instance).
3562 set breakpoint always-inserted
3563 show breakpoint always-inserted
3564 Keep breakpoints always inserted in the target, as opposed to inserting
3565 them when resuming the target, and removing them when the target stops.
3566 This option can improve debugger performance on slow remote targets.
3568 set arm fallback-mode (arm|thumb|auto)
3569 show arm fallback-mode
3570 set arm force-mode (arm|thumb|auto)
3572 These commands control how ARM GDB determines whether instructions
3573 are ARM or Thumb. The default for both settings is auto, which uses
3574 the current CPSR value for instructions without symbols; previous
3575 versions of GDB behaved as if "set arm fallback-mode arm".
3577 set disable-randomization
3578 show disable-randomization
3579 Standalone programs run with the virtual address space randomization enabled
3580 by default on some platforms. This option keeps the addresses stable across
3581 multiple debugging sessions.
3585 Control whether other threads are stopped or not when some thread hits
3590 Requests that asynchronous execution is enabled in the target, if available.
3591 In this case, it's possible to resume target in the background, and interact
3592 with GDB while the target is running. "show target-async" displays the
3593 current state of asynchronous execution of the target.
3595 set target-wide-charset
3596 show target-wide-charset
3597 The target-wide-charset is the name of the character set that GDB
3598 uses when printing characters whose type is wchar_t.
3600 set tcp auto-retry (on|off)
3602 set tcp connect-timeout
3603 show tcp connect-timeout
3604 These commands allow GDB to retry failed TCP connections to a remote stub
3605 with a specified timeout period; this is useful if the stub is launched
3606 in parallel with GDB but may not be ready to accept connections immediately.
3608 set libthread-db-search-path
3609 show libthread-db-search-path
3610 Control list of directories which GDB will search for appropriate
3613 set schedule-multiple (on|off)
3614 show schedule-multiple
3615 Allow GDB to resume all threads of all processes or only threads of
3616 the current process.
3620 Use more aggressive caching for accesses to the stack. This improves
3621 performance of remote debugging (particularly backtraces) without
3622 affecting correctness.
3624 set interactive-mode (on|off|auto)
3625 show interactive-mode
3626 Control whether GDB runs in interactive mode (on) or not (off).
3627 When in interactive mode, GDB waits for the user to answer all
3628 queries. Otherwise, GDB does not wait and assumes the default
3629 answer. When set to auto (the default), GDB determines which
3630 mode to use based on the stdin settings.
3635 For program forks, this is replaced by the new more generic `info
3636 inferiors' command. To list checkpoints, you can still use the
3637 `info checkpoints' command, which was an alias for the `info forks'
3641 Replaced by the new `inferior' command. To switch between
3642 checkpoints, you can still use the `restart' command, which was an
3643 alias for the `fork' command.
3646 This is removed, since some targets don't have a notion of
3647 processes. To switch between processes, you can still use the
3648 `inferior' command using GDB's own inferior number.
3651 For program forks, this is replaced by the new more generic `kill
3652 inferior' command. To delete a checkpoint, you can still use the
3653 `delete checkpoint' command, which was an alias for the `delete
3657 For program forks, this is replaced by the new more generic `detach
3658 inferior' command. To detach a checkpoint, you can still use the
3659 `detach checkpoint' command, which was an alias for the `detach
3662 * New native configurations
3664 x86/x86_64 Darwin i[34567]86-*-darwin*
3666 x86_64 MinGW x86_64-*-mingw*
3670 Lattice Mico32 lm32-*
3671 x86 DICOS i[34567]86-*-dicos*
3672 x86_64 DICOS x86_64-*-dicos*
3675 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3676 (mingw32ce) debugging.
3682 These commands were actually not implemented on any target.
3684 *** Changes in GDB 6.8
3686 * New native configurations
3688 NetBSD/hppa hppa*-*netbsd*
3689 Xtensa GNU/Linux xtensa*-*-linux*
3693 NetBSD/hppa hppa*-*-netbsd*
3694 Xtensa GNU/Lunux xtensa*-*-linux*
3696 * Change in command line behavior -- corefiles vs. process ids.
3698 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3699 attaching to process NUMBER fails, GDB no longer attempts to open a
3700 core file named NUMBER. Attaching to a program using the -c option
3701 is no longer supported. Instead, use the '-p' or '--pid' options.
3703 * GDB can now be built as a native debugger for debugging Windows x86
3704 (mingw32) Portable Executable (PE) programs.
3706 * Pending breakpoints no longer change their number when their address
3709 * GDB now supports breakpoints with multiple locations,
3710 including breakpoints on C++ constructors, inside C++ templates,
3711 and in inlined functions.
3713 * GDB's ability to debug optimized code has been improved. GDB more
3714 accurately identifies function bodies and lexical blocks that occupy
3715 more than one contiguous range of addresses.
3717 * Target descriptions can now describe registers for PowerPC.
3719 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3720 registers on PowerPC targets.
3722 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3723 targets even when the libthread_db library is not available.
3725 * The GDB remote stub, gdbserver, now supports the new file transfer
3726 commands (remote put, remote get, and remote delete).
3728 * The GDB remote stub, gdbserver, now supports run and attach in
3729 extended-remote mode.
3731 * hppa*64*-*-hpux11* target broken
3732 The debugger is unable to start a program and fails with the following
3733 error: "Error trying to get information about dynamic linker".
3734 The gdb-6.7 release is also affected.
3736 * GDB now supports the --enable-targets= configure option to allow
3737 building a single GDB executable that supports multiple remote
3738 target architectures.
3740 * GDB now supports debugging C and C++ programs which use the
3741 Decimal Floating Point extension. In addition, the PowerPC target
3742 now has a set of pseudo-registers to inspect decimal float values
3743 stored in two consecutive float registers.
3745 * The -break-insert MI command can optionally create pending
3748 * Improved support for debugging Ada
3749 Many improvements to the Ada language support have been made. These
3751 - Better support for Ada2005 interface types
3752 - Improved handling of arrays and slices in general
3753 - Better support for Taft-amendment types
3754 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3756 - Improved command completion in Ada
3759 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3764 set print frame-arguments (all|scalars|none)
3765 show print frame-arguments
3766 The value of this variable can be changed to control which argument
3767 values should be printed by the debugger when displaying a frame.
3772 Transfer files to and from a remote target, and delete remote files.
3779 Transfer files to and from a remote target, and delete remote files.
3781 * New remote packets
3788 Open, close, read, write, and delete files on the remote system.
3791 Attach to an existing process on the remote system, in extended-remote
3795 Run a new process on the remote system, in extended-remote mode.
3797 *** Changes in GDB 6.7
3799 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3800 bfd, libiberty and opcodes, as revealed by static analysis donated by
3801 Coverity, Inc. (http://scan.coverity.com).
3803 * When looking up multiply-defined global symbols, GDB will now prefer the
3804 symbol definition in the current shared library if it was built using the
3805 -Bsymbolic linker option.
3807 * When the Text User Interface (TUI) is not configured, GDB will now
3808 recognize the -tui command-line option and print a message that the TUI
3811 * The GDB remote stub, gdbserver, now has lower overhead for high
3812 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3814 * GDB for MIPS targets now autodetects whether a remote target provides
3815 32-bit or 64-bit register values.
3817 * Support for C++ member pointers has been improved.
3819 * GDB now understands XML target descriptions, which specify the
3820 target's overall architecture. GDB can read a description from
3821 a local file or over the remote serial protocol.
3823 * Vectors of single-byte data use a new integer type which is not
3824 automatically displayed as character or string data.
3826 * The /s format now works with the print command. It displays
3827 arrays of single-byte integers and pointers to single-byte integers
3830 * Target descriptions can now describe target-specific registers,
3831 for architectures which have implemented the support (currently
3832 only ARM, M68K, and MIPS).
3834 * GDB and the GDB remote stub, gdbserver, now support the XScale
3837 * The GDB remote stub, gdbserver, has been updated to support
3838 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3839 has been rewritten to use the standard GDB remote protocol.
3841 * GDB can now step into C++ functions which are called through thunks.
3843 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3845 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3846 layout. It also supports a TextSeg= and DataSeg= response when only
3847 segment base addresses (rather than offsets) are available.
3849 * The /i format now outputs any trailing branch delay slot instructions
3850 immediately following the last instruction within the count specified.
3852 * The GDB remote protocol "T" stop reply packet now supports a
3853 "library" response. Combined with the new "qXfer:libraries:read"
3854 packet, this response allows GDB to debug shared libraries on targets
3855 where the operating system manages the list of loaded libraries (e.g.
3856 Windows and SymbianOS).
3858 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3859 (DLLs) on Windows and Windows CE targets.
3861 * GDB now supports a faster verification that a .debug file matches its binary
3862 according to its build-id signature, if the signature is present.
3868 Enable or disable hardware flow control (RTS/CTS) on the serial port
3869 when debugging using remote targets.
3871 set mem inaccessible-by-default
3872 show mem inaccessible-by-default
3873 If the target supplies a memory map, for instance via the remote
3874 protocol's "qXfer:memory-map:read" packet, setting this variable
3875 prevents GDB from accessing memory outside the memory map. This
3876 is useful for targets with memory mapped registers or which react
3877 badly to accesses of unmapped address space.
3879 set breakpoint auto-hw
3880 show breakpoint auto-hw
3881 If the target supplies a memory map, for instance via the remote
3882 protocol's "qXfer:memory-map:read" packet, setting this variable
3883 lets GDB use hardware breakpoints automatically for memory regions
3884 where it can not use software breakpoints. This covers both the
3885 "break" command and internal breakpoints used for other commands
3886 including "next" and "finish".
3889 catch exception unhandled
3890 Stop the program execution when Ada exceptions are raised.
3893 Stop the program execution when an Ada assertion failed.
3897 Set an alternate system root for target files. This is a more
3898 general version of "set solib-absolute-prefix", which is now
3899 an alias to "set sysroot".
3902 Provide extended SPU facility status information. This set of
3903 commands is available only when debugging the Cell/B.E. SPU
3906 * New native configurations
3908 OpenBSD/sh sh*-*openbsd*
3911 unset tdesc filename
3913 Use the specified local file as an XML target description, and do
3914 not query the target for its built-in description.
3918 OpenBSD/sh sh*-*-openbsd*
3919 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3920 Toshiba Media Processor mep-elf
3922 * New remote packets
3925 Ignore the specified signals; pass them directly to the debugged program
3926 without stopping other threads or reporting them to GDB.
3928 qXfer:features:read:
3929 Read an XML target description from the target, which describes its
3934 Read or write contents of an spufs file on the target system. These
3935 packets are available only on the Cell/B.E. SPU architecture.
3937 qXfer:libraries:read:
3938 Report the loaded shared libraries. Combined with new "T" packet
3939 response, this packet allows GDB to debug shared libraries on
3940 targets where the operating system manages the list of loaded
3941 libraries (e.g. Windows and SymbianOS).
3945 Support for these obsolete configurations has been removed.
3953 i[34567]86-*-lynxos*
3954 i[34567]86-*-netware*
3955 i[34567]86-*-sco3.2v5*
3956 i[34567]86-*-sco3.2v4*
3958 i[34567]86-*-sysv4.2*
3961 i[34567]86-*-unixware2*
3962 i[34567]86-*-unixware*
3971 * Other removed features
3978 Various m68k-only ROM monitors.
3985 Various Renesas ROM monitors and debugging interfaces for SH and
3990 Support for a Macraigor serial interface to on-chip debugging.
3991 GDB does not directly support the newer parallel or USB
3996 A debug information format. The predecessor to DWARF 2 and
3997 DWARF 3, which are still supported.
3999 Support for the HP aCC compiler on HP-UX/PA-RISC
4001 SOM-encapsulated symbolic debugging information, automatic
4002 invocation of pxdb, and the aCC custom C++ ABI. This does not
4003 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4004 with aCC can still be debugged on an assembly level.
4006 MIPS ".pdr" sections
4008 A MIPS-specific format used to describe stack frame layout
4009 in debugging information.
4013 GDB could work with an older version of Guile to debug
4014 the interpreter and Scheme programs running in it.
4016 set mips stack-arg-size
4017 set mips saved-gpreg-size
4019 Use "set mips abi" to control parameter passing for MIPS.
4021 *** Changes in GDB 6.6
4026 Cell Broadband Engine SPU spu-elf
4028 * GDB can now be configured as a cross-debugger targeting native Windows
4029 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4030 running on a Windows system over TCP/IP to debug Windows programs.
4032 * The GDB remote stub, gdbserver, has been updated to support Windows and
4033 Cygwin debugging. Both single-threaded and multi-threaded programs are
4036 * The "set trust-readonly-sections" command works again. This command was
4037 broken in GDB 6.3, 6.4, and 6.5.
4039 * The "load" command now supports writing to flash memory, if the remote
4040 stub provides the required support.
4042 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4043 longer requires symbolic debug information (e.g. DWARF-2).
4048 unset substitute-path
4049 show substitute-path
4050 Manage a list of substitution rules that GDB uses to rewrite the name
4051 of the directories where the sources are located. This can be useful
4052 for instance when the sources were moved to a different location
4053 between compilation and debugging.
4057 Print each CLI command as it is executed. Each command is prefixed with
4058 a number of `+' symbols representing the nesting depth.
4059 The source command now has a `-v' option to enable the same feature.
4063 The ARM Demon monitor support (RDP protocol, "target rdp").
4065 Kernel Object Display, an embedded debugging feature which only worked with
4066 an obsolete version of Cisco IOS.
4068 The 'set download-write-size' and 'show download-write-size' commands.
4070 * New remote packets
4073 Tell a stub about GDB client features, and request remote target features.
4074 The first feature implemented is PacketSize, which allows the target to
4075 specify the size of packets it can handle - to minimize the number of
4076 packets required and improve performance when connected to a remote
4080 Fetch an OS auxilliary vector from the remote stub. This packet is a
4081 more efficient replacement for qPart:auxv:read.
4083 qXfer:memory-map:read:
4084 Fetch a memory map from the remote stub, including information about
4085 RAM, ROM, and flash memory devices.
4090 Erase and program a flash memory device.
4092 * Removed remote packets
4095 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4096 used it, and only gdbserver implemented it.
4098 *** Changes in GDB 6.5
4102 Renesas M32C/M16C m32c-elf
4104 Morpho Technologies ms1 ms1-elf
4108 init-if-undefined Initialize a convenience variable, but
4109 only if it doesn't already have a value.
4111 The following commands are presently only implemented for native GNU/Linux:
4113 checkpoint Save a snapshot of the program state.
4115 restart <n> Return the program state to a
4116 previously saved state.
4118 info checkpoints List currently saved checkpoints.
4120 delete-checkpoint <n> Delete a previously saved checkpoint.
4122 set|show detach-on-fork Tell gdb whether to detach from a newly
4123 forked process, or to keep debugging it.
4125 info forks List forks of the user program that
4126 are available to be debugged.
4128 fork <n> Switch to debugging one of several
4129 forks of the user program that are
4130 available to be debugged.
4132 delete-fork <n> Delete a fork from the list of forks
4133 that are available to be debugged (and
4134 kill the forked process).
4136 detach-fork <n> Delete a fork from the list of forks
4137 that are available to be debugged (and
4138 allow the process to continue).
4142 Morpho Technologies ms2 ms1-elf
4144 * Improved Windows host support
4146 GDB now builds as a cross debugger hosted on i686-mingw32, including
4147 native console support, and remote communications using either
4148 network sockets or serial ports.
4150 * Improved Modula-2 language support
4152 GDB can now print most types in the Modula-2 syntax. This includes:
4153 basic types, set types, record types, enumerated types, range types,
4154 pointer types and ARRAY types. Procedure var parameters are correctly
4155 printed and hexadecimal addresses and character constants are also
4156 written in the Modula-2 syntax. Best results can be obtained by using
4157 GNU Modula-2 together with the -gdwarf-2 command line option.
4161 The ARM rdi-share module.
4163 The Netware NLM debug server.
4165 *** Changes in GDB 6.4
4167 * New native configurations
4169 OpenBSD/arm arm*-*-openbsd*
4170 OpenBSD/mips64 mips64-*-openbsd*
4174 Morpho Technologies ms1 ms1-elf
4176 * New command line options
4178 --batch-silent As for --batch, but totally silent.
4179 --return-child-result The debugger will exist with the same value
4180 the child (debugged) program exited with.
4181 --eval-command COMMAND, -ex COMMAND
4182 Execute a single GDB CLI command. This may be
4183 specified multiple times and in conjunction
4184 with the --command (-x) option.
4186 * Deprecated commands removed
4188 The following commands, that were deprecated in 2000, have been
4192 set|show arm disassembly-flavor set|show arm disassembler
4193 othernames set arm disassembler
4194 set|show remotedebug set|show debug remote
4195 set|show archdebug set|show debug arch
4196 set|show eventdebug set|show debug event
4199 * New BSD user-level threads support
4201 It is now possible to debug programs using the user-level threads
4202 library on OpenBSD and FreeBSD. Currently supported (target)
4205 FreeBSD/amd64 x86_64-*-freebsd*
4206 FreeBSD/i386 i386-*-freebsd*
4207 OpenBSD/i386 i386-*-openbsd*
4209 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4210 are not yet supported.
4212 * New support for Matsushita MN10300 w/sim added
4213 (Work in progress). mn10300-elf.
4215 * REMOVED configurations and files
4217 VxWorks and the XDR protocol *-*-vxworks
4218 Motorola MCORE mcore-*-*
4219 National Semiconductor NS32000 ns32k-*-*
4221 * New "set print array-indexes" command
4223 After turning this setting "on", GDB prints the index of each element
4224 when displaying arrays. The default is "off" to preserve the previous
4227 * VAX floating point support
4229 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4231 * User-defined command support
4233 In addition to using $arg0..$arg9 for argument passing, it is now possible
4234 to use $argc to determine now many arguments have been passed. See the
4235 section on user-defined commands in the user manual for more information.
4237 *** Changes in GDB 6.3:
4239 * New command line option
4241 GDB now accepts -l followed by a number to set the timeout for remote
4244 * GDB works with GCC -feliminate-dwarf2-dups
4246 GDB now supports a more compact representation of DWARF-2 debug
4247 information using DW_FORM_ref_addr references. These are produced
4248 by GCC with the option -feliminate-dwarf2-dups and also by some
4249 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4250 to use -feliminate-dwarf2-dups.
4252 * Internationalization
4254 When supported by the host system, GDB will be built with
4255 internationalization (libintl). The task of marking up the sources is
4256 continued, we're looking forward to our first translation.
4260 Initial support for debugging programs compiled with the GNAT
4261 implementation of the Ada programming language has been integrated
4262 into GDB. In this release, support is limited to expression evaluation.
4264 * New native configurations
4266 GNU/Linux/m32r m32r-*-linux-gnu
4270 GDB's remote protocol now includes support for the 'p' packet. This
4271 packet is used to fetch individual registers from a remote inferior.
4273 * END-OF-LIFE registers[] compatibility module
4275 GDB's internal register infrastructure has been completely rewritten.
4276 The new infrastructure making possible the implementation of key new
4277 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4280 GDB 6.3 will be the last release to include the the registers[]
4281 compatibility module that allowed out-of-date configurations to
4282 continue to work. This change directly impacts the following
4292 powerpc bdm protocol
4294 Unless there is activity to revive these configurations, they will be
4295 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4297 * OBSOLETE configurations and files
4299 Configurations that have been declared obsolete in this release have
4300 been commented out. Unless there is activity to revive these
4301 configurations, the next release of GDB will have their sources
4302 permanently REMOVED.
4311 *** Changes in GDB 6.2.1:
4313 * MIPS `break main; run' gave an heuristic-fence-post warning
4315 When attempting to run even a simple program, a warning about
4316 heuristic-fence-post being hit would be reported. This problem has
4319 * MIPS IRIX 'long double' crashed GDB
4321 When examining a long double variable, GDB would get a segmentation
4322 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4323 IRIX long double values).
4327 A bug in the VAX stack code was causing problems with the "next"
4328 command. This problem has been fixed.
4330 *** Changes in GDB 6.2:
4332 * Fix for ``many threads''
4334 On GNU/Linux systems that use the NPTL threads library, a program
4335 rapidly creating and deleting threads would confuse GDB leading to the
4338 ptrace: No such process.
4339 thread_db_get_info: cannot get thread info: generic error
4341 This problem has been fixed.
4343 * "-async" and "-noasync" options removed.
4345 Support for the broken "-noasync" option has been removed (it caused
4348 * New ``start'' command.
4350 This command runs the program until the begining of the main procedure.
4352 * New BSD Kernel Data Access Library (libkvm) interface
4354 Using ``target kvm'' it is now possible to debug kernel core dumps and
4355 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4356 platforms. Currently supported (native-only) configurations are:
4358 FreeBSD/amd64 x86_64-*-freebsd*
4359 FreeBSD/i386 i?86-*-freebsd*
4360 NetBSD/i386 i?86-*-netbsd*
4361 NetBSD/m68k m68*-*-netbsd*
4362 NetBSD/sparc sparc-*-netbsd*
4363 OpenBSD/amd64 x86_64-*-openbsd*
4364 OpenBSD/i386 i?86-*-openbsd*
4365 OpenBSD/m68k m68*-openbsd*
4366 OpenBSD/sparc sparc-*-openbsd*
4368 * Signal trampoline code overhauled
4370 Many generic problems with GDB's signal handling code have been fixed.
4371 These include: backtraces through non-contiguous stacks; recognition
4372 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4373 call; backtrace through a signal trampoline; step into and out of
4374 signal handlers; and single-stepping in the signal trampoline.
4376 Please note that kernel bugs are a limiting factor here. These
4377 features have been shown to work on an s390 GNU/Linux system that
4378 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4380 * Cygwin support for DWARF 2 added.
4382 * New native configurations
4384 GNU/Linux/hppa hppa*-*-linux*
4385 OpenBSD/hppa hppa*-*-openbsd*
4386 OpenBSD/m68k m68*-*-openbsd*
4387 OpenBSD/m88k m88*-*-openbsd*
4388 OpenBSD/powerpc powerpc-*-openbsd*
4389 NetBSD/vax vax-*-netbsd*
4390 OpenBSD/vax vax-*-openbsd*
4392 * END-OF-LIFE frame compatibility module
4394 GDB's internal frame infrastructure has been completely rewritten.
4395 The new infrastructure making it possible to support key new features
4396 including DWARF 2 Call Frame Information. To aid in the task of
4397 migrating old configurations to this new infrastructure, a
4398 compatibility module, that allowed old configurations to continue to
4399 work, was also included.
4401 GDB 6.2 will be the last release to include this frame compatibility
4402 module. This change directly impacts the following configurations:
4412 Unless there is activity to revive these configurations, they will be
4413 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4415 * REMOVED configurations and files
4417 Sun 3, running SunOS 3 m68*-*-sunos3*
4418 Sun 3, running SunOS 4 m68*-*-sunos4*
4419 Sun 2, running SunOS 3 m68000-*-sunos3*
4420 Sun 2, running SunOS 4 m68000-*-sunos4*
4421 Motorola 680x0 running LynxOS m68*-*-lynxos*
4422 AT&T 3b1/Unix pc m68*-att-*
4423 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4424 decstation mips-dec-* mips-little-*
4425 riscos mips-*-riscos* mips-*-sysv*
4426 sonymips mips-sony-*
4427 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4429 *** Changes in GDB 6.1.1:
4431 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4433 The TUI (Text-mode User Interface) is now built as part of a default
4434 GDB configuration. It is enabled by either selecting the TUI with the
4435 command line option "-i=tui" or by running the separate "gdbtui"
4436 program. For more information on the TUI, see the manual "Debugging
4439 * Pending breakpoint support (also included in GDB 6.1)
4441 Support has been added to allow you to specify breakpoints in shared
4442 libraries that have not yet been loaded. If a breakpoint location
4443 cannot be found, and the "breakpoint pending" option is set to auto,
4444 GDB queries you if you wish to make the breakpoint pending on a future
4445 shared-library load. If and when GDB resolves the breakpoint symbol,
4446 the pending breakpoint is removed as one or more regular breakpoints
4449 Pending breakpoints are very useful for GCJ Java debugging.
4451 * Fixed ISO-C build problems
4453 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4454 non ISO-C code that stopped them being built using a more strict ISO-C
4455 compiler (e.g., IBM's C compiler).
4457 * Fixed build problem on IRIX 5
4459 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4460 wasn't able to compile compile on an IRIX 5 system.
4462 * Added execute permission to gdb/gdbserver/configure
4464 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4465 permission. This bug would cause configure to fail on a number of
4466 systems (Solaris, IRIX). Ref: server/519.
4468 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4470 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4471 has been updated to use constant array sizes.
4473 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4475 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4476 its generated DWARF Call Frame Info. This encoding was causing GDB to
4477 panic, that panic has been fixed. Ref: gdb/1628.
4479 * Fixed a problem when examining parameters in shared library code.
4481 When examining parameters in optimized shared library code generated
4482 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4483 not available''. GDB now correctly displays the variable's value.
4485 *** Changes in GDB 6.1:
4487 * Removed --with-mmalloc
4489 Support for the mmalloc memory manager has been removed, as it
4490 conflicted with the internal gdb byte cache.
4492 * Changes in AMD64 configurations
4494 The AMD64 target now includes the %cs and %ss registers. As a result
4495 the AMD64 remote protocol has changed; this affects the floating-point
4496 and SSE registers. If you rely on those registers for your debugging,
4497 you should upgrade gdbserver on the remote side.
4499 * Revised SPARC target
4501 The SPARC target has been completely revised, incorporating the
4502 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4503 support for LynxOS and SunOS 4 has been dropped. Calling functions
4504 from within GDB on operating systems with a non-executable stack
4505 (Solaris, OpenBSD) now works.
4509 GDB has a new C++ demangler which does a better job on the mangled
4510 names generated by current versions of g++. It also runs faster, so
4511 with this and other changes gdb should now start faster on large C++
4514 * DWARF 2 Location Expressions
4516 GDB support for location expressions has been extended to support function
4517 arguments and frame bases. Older versions of GDB could crash when they
4520 * C++ nested types and namespaces
4522 GDB's support for nested types and namespaces in C++ has been
4523 improved, especially if you use the DWARF 2 debugging format. (This
4524 is the default for recent versions of GCC on most platforms.)
4525 Specifically, if you have a class "Inner" defined within a class or
4526 namespace "Outer", then GDB realizes that the class's name is
4527 "Outer::Inner", not simply "Inner". This should greatly reduce the
4528 frequency of complaints about not finding RTTI symbols. In addition,
4529 if you are stopped at inside of a function defined within a namespace,
4530 GDB modifies its name lookup accordingly.
4532 * New native configurations
4534 NetBSD/amd64 x86_64-*-netbsd*
4535 OpenBSD/amd64 x86_64-*-openbsd*
4536 OpenBSD/alpha alpha*-*-openbsd*
4537 OpenBSD/sparc sparc-*-openbsd*
4538 OpenBSD/sparc64 sparc64-*-openbsd*
4540 * New debugging protocols
4542 M32R with SDI protocol m32r-*-elf*
4544 * "set prompt-escape-char" command deleted.
4546 The command "set prompt-escape-char" has been deleted. This command,
4547 and its very obscure effet on GDB's prompt, was never documented,
4548 tested, nor mentioned in the NEWS file.
4550 * OBSOLETE configurations and files
4552 Configurations that have been declared obsolete in this release have
4553 been commented out. Unless there is activity to revive these
4554 configurations, the next release of GDB will have their sources
4555 permanently REMOVED.
4557 Sun 3, running SunOS 3 m68*-*-sunos3*
4558 Sun 3, running SunOS 4 m68*-*-sunos4*
4559 Sun 2, running SunOS 3 m68000-*-sunos3*
4560 Sun 2, running SunOS 4 m68000-*-sunos4*
4561 Motorola 680x0 running LynxOS m68*-*-lynxos*
4562 AT&T 3b1/Unix pc m68*-att-*
4563 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4564 decstation mips-dec-* mips-little-*
4565 riscos mips-*-riscos* mips-*-sysv*
4566 sonymips mips-sony-*
4567 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4569 * REMOVED configurations and files
4571 SGI Irix-4.x mips-sgi-irix4 or iris4
4572 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4573 Z8000 simulator z8k-zilog-none or z8ksim
4574 Matsushita MN10200 w/simulator mn10200-*-*
4575 H8/500 simulator h8500-hitachi-hms or h8500hms
4576 HP/PA running BSD hppa*-*-bsd*
4577 HP/PA running OSF/1 hppa*-*-osf*
4578 HP/PA Pro target hppa*-*-pro*
4579 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4580 386BSD i[3456]86-*-bsd*
4581 Sequent family i[3456]86-sequent-sysv4*
4582 i[3456]86-sequent-sysv*
4583 i[3456]86-sequent-bsd*
4584 SPARC running LynxOS sparc-*-lynxos*
4585 SPARC running SunOS 4 sparc-*-sunos4*
4586 Tsqware Sparclet sparclet-*-*
4587 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4589 *** Changes in GDB 6.0:
4593 Support for debugging the Objective-C programming language has been
4594 integrated into GDB.
4596 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4598 DWARF 2's Call Frame Information makes available compiler generated
4599 information that more exactly describes the program's run-time stack.
4600 By using this information, GDB is able to provide more robust stack
4603 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4604 have been updated to use a new backtrace mechanism which includes
4605 DWARF 2 CFI support.
4609 GDB's remote protocol has been extended to include support for hosted
4610 file I/O (where the remote target uses GDB's file system). See GDB's
4611 remote protocol documentation for details.
4613 * All targets using the new architecture framework.
4615 All of GDB's targets have been updated to use the new internal
4616 architecture framework. The way is now open for future GDB releases
4617 to include cross-architecture native debugging support (i386 on amd64,
4620 * GNU/Linux's Thread Local Storage (TLS)
4622 GDB now includes support for for the GNU/Linux implementation of
4623 per-thread variables.
4625 * GNU/Linux's Native POSIX Thread Library (NPTL)
4627 GDB's thread code has been updated to work with either the new
4628 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4630 * Separate debug info.
4632 GDB, in conjunction with BINUTILS, now supports a mechanism for
4633 automatically loading debug information from a separate file. Instead
4634 of shipping full debug and non-debug versions of system libraries,
4635 system integrators can now instead ship just the stripped libraries
4636 and optional debug files.
4638 * DWARF 2 Location Expressions
4640 DWARF 2 Location Expressions allow the compiler to more completely
4641 describe the location of variables (even in optimized code) to the
4644 GDB now includes preliminary support for location expressions (support
4645 for DW_OP_piece is still missing).
4649 A number of long standing bugs that caused GDB to die while starting a
4650 Java application have been fixed. GDB's Java support is now
4651 considered "useable".
4653 * GNU/Linux support for fork, vfork, and exec.
4655 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4656 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4659 * GDB supports logging output to a file
4661 There are two new commands, "set logging" and "show logging", which can be
4662 used to capture GDB's output to a file.
4664 * The meaning of "detach" has changed for gdbserver
4666 The "detach" command will now resume the application, as documented. To
4667 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4670 * d10v, m68hc11 `regs' command deprecated
4672 The `info registers' command has been updated so that it displays the
4673 registers using a format identical to the old `regs' command.
4677 A new command, "maint set profile on/off", has been added. This command can
4678 be used to enable or disable profiling while running GDB, to profile a
4679 session or a set of commands. In addition there is a new configure switch,
4680 "--enable-profiling", which will cause GDB to be compiled with profiling
4681 data, for more informative profiling results.
4683 * Default MI syntax changed to "mi2".
4685 The default MI (machine interface) syntax, enabled by the command line
4686 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4687 "mi1", can be enabled by specifying the option "-i=mi1".
4689 Support for the original "mi0" syntax (included in GDB 5.0) has been
4692 Fix for gdb/192: removed extraneous space when displaying frame level.
4693 Fix for gdb/672: update changelist is now output in mi list format.
4694 Fix for gdb/702: a -var-assign that updates the value now shows up
4695 in a subsequent -var-update.
4697 * New native configurations.
4699 FreeBSD/amd64 x86_64-*-freebsd*
4701 * Multi-arched targets.
4703 HP/PA HPUX11 hppa*-*-hpux*
4704 Renesas M32R/D w/simulator m32r-*-elf*
4706 * OBSOLETE configurations and files
4708 Configurations that have been declared obsolete in this release have
4709 been commented out. Unless there is activity to revive these
4710 configurations, the next release of GDB will have their sources
4711 permanently REMOVED.
4713 Z8000 simulator z8k-zilog-none or z8ksim
4714 Matsushita MN10200 w/simulator mn10200-*-*
4715 H8/500 simulator h8500-hitachi-hms or h8500hms
4716 HP/PA running BSD hppa*-*-bsd*
4717 HP/PA running OSF/1 hppa*-*-osf*
4718 HP/PA Pro target hppa*-*-pro*
4719 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4720 Sequent family i[3456]86-sequent-sysv4*
4721 i[3456]86-sequent-sysv*
4722 i[3456]86-sequent-bsd*
4723 Tsqware Sparclet sparclet-*-*
4724 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4726 * REMOVED configurations and files
4729 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4730 IBM AIX PS/2 i[3456]86-*-aix
4731 i386 running Mach 3.0 i[3456]86-*-mach3*
4732 i386 running Mach i[3456]86-*-mach*
4733 i386 running OSF/1 i[3456]86-*osf1mk*
4734 HP/Apollo 68k Family m68*-apollo*-sysv*,
4736 m68*-hp-bsd*, m68*-hp-hpux*
4737 Argonaut Risc Chip (ARC) arc-*-*
4738 Mitsubishi D30V d30v-*-*
4739 Fujitsu FR30 fr30-*-elf*
4740 OS/9000 i[34]86-*-os9k
4741 I960 with MON960 i960-*-coff
4743 * MIPS $fp behavior changed
4745 The convenience variable $fp, for the MIPS, now consistently returns
4746 the address of the current frame's base. Previously, depending on the
4747 context, $fp could refer to either $sp or the current frame's base
4748 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4749 The GNU Source-Level Debugger''.
4751 *** Changes in GDB 5.3:
4753 * GNU/Linux shared library multi-threaded performance improved.
4755 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4756 `/proc', in preference to `ptrace' for memory reads. This may result
4757 in an improvement in the start-up time of multi-threaded, shared
4758 library applications when run under GDB. One GDB user writes: ``loads
4759 shared libs like mad''.
4761 * ``gdbserver'' now supports multi-threaded applications on some targets
4763 Support for debugging multi-threaded applications which use
4764 the GNU/Linux LinuxThreads package has been added for
4765 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4766 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4768 * GDB now supports C/C++ preprocessor macros.
4770 GDB now expands preprocessor macro invocations in C/C++ expressions,
4771 and provides various commands for showing macro definitions and how
4774 The new command `macro expand EXPRESSION' expands any macro
4775 invocations in expression, and shows the result.
4777 The new command `show macro MACRO-NAME' shows the definition of the
4778 macro named MACRO-NAME, and where it was defined.
4780 Most compilers don't include information about macros in the debugging
4781 information by default. In GCC 3.1, for example, you need to compile
4782 your program with the options `-gdwarf-2 -g3'. If the macro
4783 information is present in the executable, GDB will read it.
4785 * Multi-arched targets.
4787 DEC Alpha (partial) alpha*-*-*
4788 DEC VAX (partial) vax-*-*
4790 National Semiconductor NS32000 (partial) ns32k-*-*
4791 Motorola 68000 (partial) m68k-*-*
4792 Motorola MCORE mcore-*-*
4796 Fujitsu FRV architecture added by Red Hat frv*-*-*
4799 * New native configurations
4801 Alpha NetBSD alpha*-*-netbsd*
4802 SH NetBSD sh*-*-netbsdelf*
4803 MIPS NetBSD mips*-*-netbsd*
4804 UltraSPARC NetBSD sparc64-*-netbsd*
4806 * OBSOLETE configurations and files
4808 Configurations that have been declared obsolete in this release have
4809 been commented out. Unless there is activity to revive these
4810 configurations, the next release of GDB will have their sources
4811 permanently REMOVED.
4813 Mitsubishi D30V d30v-*-*
4814 OS/9000 i[34]86-*-os9k
4815 IBM AIX PS/2 i[3456]86-*-aix
4816 Fujitsu FR30 fr30-*-elf*
4817 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4818 Argonaut Risc Chip (ARC) arc-*-*
4819 i386 running Mach 3.0 i[3456]86-*-mach3*
4820 i386 running Mach i[3456]86-*-mach*
4821 i386 running OSF/1 i[3456]86-*osf1mk*
4822 HP/Apollo 68k Family m68*-apollo*-sysv*,
4824 m68*-hp-bsd*, m68*-hp-hpux*
4825 I960 with MON960 i960-*-coff
4827 * OBSOLETE languages
4829 CHILL, a Pascal like language used by telecommunications companies.
4831 * REMOVED configurations and files
4833 AMD 29k family via UDI a29k-amd-udi, udi29k
4834 A29K VxWorks a29k-*-vxworks
4835 AMD 29000 embedded, using EBMON a29k-none-none
4836 AMD 29000 embedded with COFF a29k-none-coff
4837 AMD 29000 embedded with a.out a29k-none-aout
4839 testsuite/gdb.hp/gdb.threads-hp/ directory
4841 * New command "set max-user-call-depth <nnn>"
4843 This command allows the user to limit the call depth of user-defined
4844 commands. The default is 1024.
4846 * Changes in FreeBSD/i386 native debugging.
4848 Support for the "generate-core-file" has been added.
4850 * New commands "dump", "append", and "restore".
4852 These commands allow data to be copied from target memory
4853 to a bfd-format or binary file (dump and append), and back
4854 from a file into memory (restore).
4856 * Improved "next/step" support on multi-processor Alpha Tru64.
4858 The previous single-step mechanism could cause unpredictable problems,
4859 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4860 of a software single-step mechanism prevents this.
4862 *** Changes in GDB 5.2.1:
4870 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4871 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4872 Fix, by Joel Brobecker imported from mainline.
4874 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4875 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4876 Fix, by Fred Fish, imported from mainline.
4878 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4879 Surprisingly enough, it works now.
4880 By Michal Ludvig, imported from mainline.
4882 i386 hardware watchpoint support:
4883 avoid misses on second run for some targets.
4884 By Pierre Muller, imported from mainline.
4886 *** Changes in GDB 5.2:
4888 * New command "set trust-readonly-sections on[off]".
4890 This command is a hint that tells gdb that read-only sections
4891 really are read-only (ie. that their contents will not change).
4892 In this mode, gdb will go to the object file rather than the
4893 target to read memory from read-only sections (such as ".text").
4894 This can be a significant performance improvement on some
4895 (notably embedded) targets.
4897 * New command "generate-core-file" (or "gcore").
4899 This new gdb command allows the user to drop a core file of the child
4900 process state at any time. So far it's been implemented only for
4901 GNU/Linux and Solaris, but should be relatively easily ported to other
4902 hosts. Argument is core file name (defaults to core.<pid>).
4904 * New command line option
4906 GDB now accepts --pid or -p followed by a process id.
4908 * Change in command line behavior -- corefiles vs. process ids.
4910 There is a subtle behavior in the way in which GDB handles
4911 command line arguments. The first non-flag argument is always
4912 a program to debug, but the second non-flag argument may either
4913 be a corefile or a process id. Previously, GDB would attempt to
4914 open the second argument as a corefile, and if that failed, would
4915 issue a superfluous error message and then attempt to attach it as
4916 a process. Now, if the second argument begins with a non-digit,
4917 it will be treated as a corefile. If it begins with a digit,
4918 GDB will attempt to attach it as a process, and if no such process
4919 is found, will then attempt to open it as a corefile.
4921 * Changes in ARM configurations.
4923 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4924 configuration is fully multi-arch.
4926 * New native configurations
4928 ARM NetBSD arm*-*-netbsd*
4929 x86 OpenBSD i[3456]86-*-openbsd*
4930 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4931 Sparc64 running FreeBSD sparc64-*-freebsd*
4935 Sanyo XStormy16 xstormy16-elf
4937 * OBSOLETE configurations and files
4939 Configurations that have been declared obsolete in this release have
4940 been commented out. Unless there is activity to revive these
4941 configurations, the next release of GDB will have their sources
4942 permanently REMOVED.
4944 AMD 29k family via UDI a29k-amd-udi, udi29k
4945 A29K VxWorks a29k-*-vxworks
4946 AMD 29000 embedded, using EBMON a29k-none-none
4947 AMD 29000 embedded with COFF a29k-none-coff
4948 AMD 29000 embedded with a.out a29k-none-aout
4950 testsuite/gdb.hp/gdb.threads-hp/ directory
4952 * REMOVED configurations and files
4954 TI TMS320C80 tic80-*-*
4956 PowerPC Solaris powerpcle-*-solaris*
4957 PowerPC Windows NT powerpcle-*-cygwin32
4958 PowerPC Netware powerpc-*-netware*
4959 Harris/CXUX m88k m88*-harris-cxux*
4960 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4961 ns32k-utek-sysv* ns32k-utek-*
4962 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4963 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4964 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4965 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4966 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4968 * Changes to command line processing
4970 The new `--args' feature can be used to specify command-line arguments
4971 for the inferior from gdb's command line.
4973 * Changes to key bindings
4975 There is a new `operate-and-get-next' function bound to `C-o'.
4977 *** Changes in GDB 5.1.1
4979 Fix compile problem on DJGPP.
4981 Fix a problem with floating-point registers on the i386 being
4984 Fix to stop GDB crashing on .debug_str debug info.
4986 Numerous documentation fixes.
4988 Numerous testsuite fixes.
4990 *** Changes in GDB 5.1:
4992 * New native configurations
4994 Alpha FreeBSD alpha*-*-freebsd*
4995 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4996 MIPS GNU/Linux mips*-*-linux*
4997 MIPS SGI Irix 6.x mips*-sgi-irix6*
4998 ia64 AIX ia64-*-aix*
4999 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5003 Motorola 68HC11 and 68HC12 m68hc11-elf
5005 UltraSparc running GNU/Linux sparc64-*-linux*
5007 * OBSOLETE configurations and files
5009 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5010 Harris/CXUX m88k m88*-harris-cxux*
5011 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5012 ns32k-utek-sysv* ns32k-utek-*
5013 TI TMS320C80 tic80-*-*
5015 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5016 PowerPC Solaris powerpcle-*-solaris*
5017 PowerPC Windows NT powerpcle-*-cygwin32
5018 PowerPC Netware powerpc-*-netware*
5019 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5020 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5021 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5022 Apple Macintosh (MPW) host N/A
5024 stuff.c (Program to stuff files into a specially prepared space in kdb)
5025 kdb-start.c (Main loop for the standalone kernel debugger)
5027 Configurations that have been declared obsolete in this release have
5028 been commented out. Unless there is activity to revive these
5029 configurations, the next release of GDB will have their sources
5030 permanently REMOVED.
5032 * REMOVED configurations and files
5034 Altos 3068 m68*-altos-*
5035 Convex c1-*-*, c2-*-*
5037 ARM RISCix arm-*-* (as host)
5041 * GDB has been converted to ISO C.
5043 GDB's source code has been converted to ISO C. In particular, the
5044 sources are fully protoized, and rely on standard headers being
5049 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5051 * The MI enabled by default.
5053 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5054 revised and enabled by default. Packages which use GDB as a debugging
5055 engine behind a UI or another front end are encouraged to switch to
5056 using the GDB/MI interface, instead of the old annotations interface
5057 which is now deprecated.
5059 * Support for debugging Pascal programs.
5061 GDB now includes support for debugging Pascal programs. The following
5062 main features are supported:
5064 - Pascal-specific data types such as sets;
5066 - automatic recognition of Pascal sources based on file-name
5069 - Pascal-style display of data types, variables, and functions;
5071 - a Pascal expression parser.
5073 However, some important features are not yet supported.
5075 - Pascal string operations are not supported at all;
5077 - there are some problems with boolean types;
5079 - Pascal type hexadecimal constants are not supported
5080 because they conflict with the internal variables format;
5082 - support for Pascal objects and classes is not full yet;
5084 - unlike Pascal, GDB is case-sensitive for symbol names.
5086 * Changes in completion.
5088 Commands such as `shell', `run' and `set args', which pass arguments
5089 to inferior programs, now complete on file names, similar to what
5090 users expect at the shell prompt.
5092 Commands which accept locations, such as `disassemble', `print',
5093 `breakpoint', `until', etc. now complete on filenames as well as
5094 program symbols. Thus, if you type "break foob TAB", and the source
5095 files linked into the programs include `foobar.c', that file name will
5096 be one of the candidates for completion. However, file names are not
5097 considered for completion after you typed a colon that delimits a file
5098 name from a name of a function in that file, as in "break foo.c:bar".
5100 `set demangle-style' completes on available demangling styles.
5102 * New platform-independent commands:
5104 It is now possible to define a post-hook for a command as well as a
5105 hook that runs before the command. For more details, see the
5106 documentation of `hookpost' in the GDB manual.
5108 * Changes in GNU/Linux native debugging.
5110 Support for debugging multi-threaded programs has been completely
5111 revised for all platforms except m68k and sparc. You can now debug as
5112 many threads as your system allows you to have.
5114 Attach/detach is supported for multi-threaded programs.
5116 Support for SSE registers was added for x86. This doesn't work for
5117 multi-threaded programs though.
5119 * Changes in MIPS configurations.
5121 Multi-arch support is enabled for all MIPS configurations.
5123 GDB can now be built as native debugger on SGI Irix 6.x systems for
5124 debugging n32 executables. (Debugging 64-bit executables is not yet
5127 * Unified support for hardware watchpoints in all x86 configurations.
5129 Most (if not all) native x86 configurations support hardware-assisted
5130 breakpoints and watchpoints in a unified manner. This support
5131 implements debug register sharing between watchpoints, which allows to
5132 put a virtually infinite number of watchpoints on the same address,
5133 and also supports watching regions up to 16 bytes with several debug
5136 The new maintenance command `maintenance show-debug-regs' toggles
5137 debugging print-outs in functions that insert, remove, and test
5138 watchpoints and hardware breakpoints.
5140 * Changes in the DJGPP native configuration.
5142 New command ``info dos sysinfo'' displays assorted information about
5143 the CPU, OS, memory, and DPMI server.
5145 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5146 display information about segment descriptors stored in GDT, LDT, and
5149 New commands ``info dos pde'' and ``info dos pte'' display entries
5150 from Page Directory and Page Tables (for now works with CWSDPMI only).
5151 New command ``info dos address-pte'' displays the Page Table entry for
5152 a given linear address.
5154 GDB can now pass command lines longer than 126 characters to the
5155 program being debugged (requires an update to the libdbg.a library
5156 which is part of the DJGPP development kit).
5158 DWARF2 debug info is now supported.
5160 It is now possible to `step' and `next' through calls to `longjmp'.
5162 * Changes in documentation.
5164 All GDB documentation was converted to GFDL, the GNU Free
5165 Documentation License.
5167 Tracepoints-related commands are now fully documented in the GDB
5170 TUI, the Text-mode User Interface, is now documented in the manual.
5172 Tracepoints-related commands are now fully documented in the GDB
5175 The "GDB Internals" manual now has an index. It also includes
5176 documentation of `ui_out' functions, GDB coding standards, x86
5177 hardware watchpoints, and memory region attributes.
5179 * GDB's version number moved to ``version.in''
5181 The Makefile variable VERSION has been replaced by the file
5182 ``version.in''. People creating GDB distributions should update the
5183 contents of this file.
5187 GUD support is now a standard part of the EMACS distribution.
5189 *** Changes in GDB 5.0:
5191 * Improved support for debugging FP programs on x86 targets
5193 Unified and much-improved support for debugging floating-point
5194 programs on all x86 targets. In particular, ``info float'' now
5195 displays the FP registers in the same format on all x86 targets, with
5196 greater level of detail.
5198 * Improvements and bugfixes in hardware-assisted watchpoints
5200 It is now possible to watch array elements, struct members, and
5201 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5202 on x86 targets no longer erroneously trigger when the address is
5205 * Improvements in the native DJGPP version of GDB
5207 The distribution now includes all the scripts and auxiliary files
5208 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5209 machines ``out of the box''.
5211 The DJGPP version can now debug programs that use signals. It is
5212 possible to catch signals that happened in the debuggee, deliver
5213 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5214 would kill the program being debugged.) Programs that hook hardware
5215 interrupts (keyboard, timer, etc.) can also be debugged.
5217 It is now possible to debug DJGPP programs that redirect their
5218 standard handles or switch them to raw (as opposed to cooked) mode, or
5219 even close them. The command ``run < foo > bar'' works as expected,
5220 and ``info terminal'' reports useful information about the debuggee's
5221 terminal, including raw/cooked mode, redirection, etc.
5223 The DJGPP version now uses termios functions for console I/O, which
5224 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5227 DOS-style file names with drive letters are now fully supported by
5230 It is now possible to debug DJGPP programs that switch their working
5231 directory. It is also possible to rerun the debuggee any number of
5232 times without restarting GDB; thus, you can use the same setup,
5233 breakpoints, etc. for many debugging sessions.
5235 * New native configurations
5237 ARM GNU/Linux arm*-*-linux*
5238 PowerPC GNU/Linux powerpc-*-linux*
5242 Motorola MCore mcore-*-*
5243 x86 VxWorks i[3456]86-*-vxworks*
5244 PowerPC VxWorks powerpc-*-vxworks*
5245 TI TMS320C80 tic80-*-*
5247 * OBSOLETE configurations
5249 Altos 3068 m68*-altos-*
5250 Convex c1-*-*, c2-*-*
5252 ARM RISCix arm-*-* (as host)
5255 Configurations that have been declared obsolete will be commented out,
5256 but the code will be left in place. If there is no activity to revive
5257 these configurations before the next release of GDB, the sources will
5258 be permanently REMOVED.
5260 * Gould support removed
5262 Support for the Gould PowerNode and NP1 has been removed.
5264 * New features for SVR4
5266 On SVR4 native platforms (such as Solaris), if you attach to a process
5267 without first loading a symbol file, GDB will now attempt to locate and
5268 load symbols from the running process's executable file.
5270 * Many C++ enhancements
5272 C++ support has been greatly improved. Overload resolution now works properly
5273 in almost all cases. RTTI support is on the way.
5275 * Remote targets can connect to a sub-program
5277 A popen(3) style serial-device has been added. This device starts a
5278 sub-process (such as a stand-alone simulator) and then communicates
5279 with that. The sub-program to run is specified using the syntax
5280 ``|<program> <args>'' vis:
5282 (gdb) set remotedebug 1
5283 (gdb) target extended-remote |mn10300-elf-sim program-args
5285 * MIPS 64 remote protocol
5287 A long standing bug in the mips64 remote protocol where by GDB
5288 expected certain 32 bit registers (ex SR) to be transfered as 32
5289 instead of 64 bits has been fixed.
5291 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5292 added to provide backward compatibility with older versions of GDB.
5294 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5296 The command ``set remotebinarydownload'' command has been replaced by
5297 ``set remote X-packet''. Other commands in ``set remote'' family
5298 include ``set remote P-packet''.
5300 * Breakpoint commands accept ranges.
5302 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5303 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5304 ``tracepoint passcount'' also accepts a range of tracepoints.
5306 * ``apropos'' command added.
5308 The ``apropos'' command searches through command names and
5309 documentation strings, printing out matches, making it much easier to
5310 try to find a command that does what you are looking for.
5314 A new machine oriented interface (MI) has been added to GDB. This
5315 interface is designed for debug environments running GDB as a separate
5316 process. This is part of the long term libGDB project. See the
5317 "GDB/MI" chapter of the GDB manual for further information. It can be
5318 enabled by configuring with:
5320 .../configure --enable-gdbmi
5322 *** Changes in GDB-4.18:
5324 * New native configurations
5326 HP-UX 10.20 hppa*-*-hpux10.20
5327 HP-UX 11.x hppa*-*-hpux11.0*
5328 M68K GNU/Linux m68*-*-linux*
5332 Fujitsu FR30 fr30-*-elf*
5333 Intel StrongARM strongarm-*-*
5334 Mitsubishi D30V d30v-*-*
5336 * OBSOLETE configurations
5338 Gould PowerNode, NP1 np1-*-*, pn-*-*
5340 Configurations that have been declared obsolete will be commented out,
5341 but the code will be left in place. If there is no activity to revive
5342 these configurations before the next release of GDB, the sources will
5343 be permanently REMOVED.
5347 As a compatibility experiment, GDB's source files buildsym.h and
5348 buildsym.c have been converted to pure standard C, no longer
5349 containing any K&R compatibility code. We believe that all systems in
5350 use today either come with a standard C compiler, or have a GCC port
5351 available. If this is not true, please report the affected
5352 configuration to bug-gdb@gnu.org immediately. See the README file for
5353 information about getting a standard C compiler if you don't have one
5358 GDB now uses readline 2.2.
5360 * set extension-language
5362 You can now control the mapping between filename extensions and source
5363 languages by using the `set extension-language' command. For instance,
5364 you can ask GDB to treat .c files as C++ by saying
5365 set extension-language .c c++
5366 The command `info extensions' lists all of the recognized extensions
5367 and their associated languages.
5369 * Setting processor type for PowerPC and RS/6000
5371 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5372 you can use the `set processor' command to specify what variant of the
5373 PowerPC family you are debugging. The command
5377 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5378 following PowerPC and RS6000 variants:
5380 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5381 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5383 403GC IBM PowerPC 403GC
5384 505 Motorola PowerPC 505
5385 860 Motorola PowerPC 860 or 850
5386 601 Motorola PowerPC 601
5387 602 Motorola PowerPC 602
5388 603 Motorola/IBM PowerPC 603 or 603e
5389 604 Motorola PowerPC 604 or 604e
5390 750 Motorola/IBM PowerPC 750 or 750
5392 At the moment, this command just tells GDB what to name the
5393 special-purpose processor registers. Since almost all the affected
5394 registers are inaccessible to user-level programs, this command is
5395 only useful for remote debugging in its present form.
5399 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5400 more extensive support for HP-UX. Added features include shared
5401 library support, kernel threads and hardware watchpoints for 11.00,
5402 support for HP's ANSI C and C++ compilers, and a compatibility mode
5403 for xdb and dbx commands.
5407 HP's donation includes the new concept of catchpoints, which is a
5408 generalization of the old catch command. On HP-UX, it is now possible
5409 to catch exec, fork, and vfork, as well as library loading.
5411 This means that the existing catch command has changed; its first
5412 argument now specifies the type of catch to be set up. See the
5413 output of "help catch" for a list of catchpoint types.
5415 * Debugging across forks
5417 On HP-UX, you can choose which process to debug when a fork() happens
5422 HP has donated a curses-based terminal user interface (TUI). To get
5423 it, build with --enable-tui. Although this can be enabled for any
5424 configuration, at present it only works for native HP debugging.
5426 * GDB remote protocol additions
5428 A new protocol packet 'X' that writes binary data is now available.
5429 Default behavior is to try 'X', then drop back to 'M' if the stub
5430 fails to respond. The settable variable `remotebinarydownload'
5431 allows explicit control over the use of 'X'.
5433 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5434 full 64-bit address. The command
5436 set remoteaddresssize 32
5438 can be used to revert to the old behaviour. For existing remote stubs
5439 the change should not be noticed, as the additional address information
5442 In order to assist in debugging stubs, you may use the maintenance
5443 command `packet' to send any text string to the stub. For instance,
5445 maint packet heythere
5447 sends the packet "$heythere#<checksum>". Note that it is very easy to
5448 disrupt a debugging session by sending the wrong packet at the wrong
5451 The compare-sections command allows you to compare section data on the
5452 target to what is in the executable file without uploading or
5453 downloading, by comparing CRC checksums.
5455 * Tracing can collect general expressions
5457 You may now collect general expressions at tracepoints. This requires
5458 further additions to the target-side stub; see tracepoint.c and
5459 doc/agentexpr.texi for further details.
5461 * mask-address variable for Mips
5463 For Mips targets, you may control the zeroing of the upper 32 bits of
5464 a 64-bit address by entering `set mask-address on'. This is mainly
5465 of interest to users of embedded R4xxx and R5xxx processors.
5467 * Higher serial baud rates
5469 GDB's serial code now allows you to specify baud rates 57600, 115200,
5470 230400, and 460800 baud. (Note that your host system may not be able
5471 to achieve all of these rates.)
5475 The i960 configuration now includes an initial implementation of a
5476 builtin simulator, contributed by Jim Wilson.
5479 *** Changes in GDB-4.17:
5481 * New native configurations
5483 Alpha GNU/Linux alpha*-*-linux*
5484 Unixware 2.x i[3456]86-unixware2*
5485 Irix 6.x mips*-sgi-irix6*
5486 PowerPC GNU/Linux powerpc-*-linux*
5487 PowerPC Solaris powerpcle-*-solaris*
5488 Sparc GNU/Linux sparc-*-linux*
5489 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5493 Argonaut Risc Chip (ARC) arc-*-*
5494 Hitachi H8/300S h8300*-*-*
5495 Matsushita MN10200 w/simulator mn10200-*-*
5496 Matsushita MN10300 w/simulator mn10300-*-*
5497 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5498 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5499 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5500 Mitsubishi D10V w/simulator d10v-*-*
5501 Mitsubishi M32R/D w/simulator m32r-*-elf*
5502 Tsqware Sparclet sparclet-*-*
5503 NEC V850 w/simulator v850-*-*
5505 * New debugging protocols
5507 ARM with RDI protocol arm*-*-*
5508 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5509 DDB and LSI variants of PMON protocol mips*-*-*
5510 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5511 PowerPC with SDS protocol powerpc{,le}-*-eabi
5512 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5516 All configurations can now understand and use the DWARF 2 debugging
5517 format. The choice is automatic, if the symbol file contains DWARF 2
5522 GDB now includes basic Java language support. This support is
5523 only useful with Java compilers that produce native machine code.
5525 * solib-absolute-prefix and solib-search-path
5527 For SunOS and SVR4 shared libraries, you may now set the prefix for
5528 loading absolute shared library symbol files, and the search path for
5529 locating non-absolute shared library symbol files.
5531 * Live range splitting
5533 GDB can now effectively debug code for which GCC has performed live
5534 range splitting as part of its optimization. See gdb/doc/LRS for
5535 more details on the expected format of the stabs information.
5539 GDB's support for the GNU Hurd, including thread debugging, has been
5540 updated to work with current versions of the Hurd.
5544 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5545 instruction set. ARM GDB automatically detects when Thumb
5546 instructions are in use, and adjusts disassembly and backtracing
5551 GDB's MIPS target configurations now handle the MIP16 16-bit
5556 GDB now includes support for overlays; if an executable has been
5557 linked such that multiple sections are based at the same address, GDB
5558 will decide which section to use for symbolic info. You can choose to
5559 control the decision manually, using overlay commands, or implement
5560 additional target-side support and use "overlay load-target" to bring
5561 in the overlay mapping. Do "help overlay" for more detail.
5565 The command "info symbol <address>" displays information about
5566 the symbol at the specified address.
5570 The standard remote protocol now includes an extension that allows
5571 asynchronous collection and display of trace data. This requires
5572 extensive support in the target-side debugging stub. Tracing mode
5573 includes a new interaction mode in GDB and new commands: see the
5574 file tracepoint.c for more details.
5578 Configurations for embedded MIPS now include a simulator contributed
5579 by Cygnus Solutions. The simulator supports the instruction sets
5580 of most MIPS variants.
5584 Sparc configurations may now include the ERC32 simulator contributed
5585 by the European Space Agency. The simulator is not built into
5586 Sparc targets by default; configure with --enable-sim to include it.
5590 For target configurations that may include multiple variants of a
5591 basic architecture (such as MIPS and SH), you may now set the
5592 architecture explicitly. "set arch" sets, "info arch" lists
5593 the possible architectures.
5595 *** Changes in GDB-4.16:
5597 * New native configurations
5599 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5600 M68K NetBSD m68k-*-netbsd*
5601 PowerPC AIX 4.x powerpc-*-aix*
5602 PowerPC MacOS powerpc-*-macos*
5603 PowerPC Windows NT powerpcle-*-cygwin32
5604 RS/6000 AIX 4.x rs6000-*-aix4*
5608 ARM with RDP protocol arm-*-*
5609 I960 with MON960 i960-*-coff
5610 MIPS VxWorks mips*-*-vxworks*
5611 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5612 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5614 Matra Sparclet sparclet-*-*
5618 The powerpc-eabi configuration now includes the PSIM simulator,
5619 contributed by Andrew Cagney, with assistance from Mike Meissner.
5620 PSIM is a very elaborate model of the PowerPC, including not only
5621 basic instruction set execution, but also details of execution unit
5622 performance and I/O hardware. See sim/ppc/README for more details.
5626 GDB now works with Solaris 2.5.
5628 * Windows 95/NT native
5630 GDB will now work as a native debugger on Windows 95 and Windows NT.
5631 To build it from source, you must use the "gnu-win32" environment,
5632 which uses a DLL to emulate enough of Unix to run the GNU tools.
5633 Further information, binaries, and sources are available at
5634 ftp.cygnus.com, under pub/gnu-win32.
5636 * dont-repeat command
5638 If a user-defined command includes the command `dont-repeat', then the
5639 command will not be repeated if the user just types return. This is
5640 useful if the command is time-consuming to run, so that accidental
5641 extra keystrokes don't run the same command many times.
5643 * Send break instead of ^C
5645 The standard remote protocol now includes an option to send a break
5646 rather than a ^C to the target in order to interrupt it. By default,
5647 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5649 * Remote protocol timeout
5651 The standard remote protocol includes a new variable `remotetimeout'
5652 that allows you to set the number of seconds before GDB gives up trying
5653 to read from the target. The default value is 2.
5655 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5657 By default GDB will automatically keep track of objects as they are
5658 loaded and unloaded by the dynamic linker. By using the command `set
5659 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5660 when shared library events occur, thus allowing you to set breakpoints
5661 in shared libraries which are explicitly loaded by the inferior.
5663 Note this feature does not work on hpux8. On hpux9 you must link
5664 /usr/lib/end.o into your program. This feature should work
5665 automatically on hpux10.
5667 * Irix 5.x hardware watchpoint support
5669 Irix 5 configurations now support the use of hardware watchpoints.
5671 * Mips protocol "SYN garbage limit"
5673 When debugging a Mips target using the `target mips' protocol, you
5674 may set the number of characters that GDB will ignore by setting
5675 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5676 every character. The default value is 1050.
5678 * Recording and replaying remote debug sessions
5680 If you set `remotelogfile' to the name of a file, gdb will write to it
5681 a recording of a remote debug session. This recording may then be
5682 replayed back to gdb using "gdbreplay". See gdbserver/README for
5683 details. This is useful when you have a problem with GDB while doing
5684 remote debugging; you can make a recording of the session and send it
5685 to someone else, who can then recreate the problem.
5687 * Speedups for remote debugging
5689 GDB includes speedups for downloading and stepping MIPS systems using
5690 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5691 and more efficient S-record downloading.
5693 * Memory use reductions and statistics collection
5695 GDB now uses less memory and reports statistics about memory usage.
5696 Try the `maint print statistics' command, for example.
5698 *** Changes in GDB-4.15:
5700 * Psymtabs for XCOFF
5702 The symbol reader for AIX GDB now uses partial symbol tables. This
5703 can greatly improve startup time, especially for large executables.
5705 * Remote targets use caching
5707 Remote targets now use a data cache to speed up communication with the
5708 remote side. The data cache could lead to incorrect results because
5709 it doesn't know about volatile variables, thus making it impossible to
5710 debug targets which use memory mapped I/O devices. `set remotecache
5711 off' turns the the data cache off.
5713 * Remote targets may have threads
5715 The standard remote protocol now includes support for multiple threads
5716 in the target system, using new protocol commands 'H' and 'T'. See
5717 gdb/remote.c for details.
5721 If GDB is configured with `--enable-netrom', then it will include
5722 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5723 acts as though it is a bank of ROM on the target board, but you can
5724 write into it over the network. GDB's support consists only of
5725 support for fast loading into the emulated ROM; to debug, you must use
5726 another protocol, such as standard remote protocol. The usual
5727 sequence is something like
5729 target nrom <netrom-hostname>
5731 target remote <netrom-hostname>:1235
5735 GDB now includes support for the Apple Macintosh, as a host only. It
5736 may be run as either an MPW tool or as a standalone application, and
5737 it can debug through the serial port. All the usual GDB commands are
5738 available, but to the target command, you must supply "serial" as the
5739 device type instead of "/dev/ttyXX". See mpw-README in the main
5740 directory for more information on how to build. The MPW configuration
5741 scripts */mpw-config.in support only a few targets, and only the
5742 mips-idt-ecoff target has been tested.
5746 GDB configuration now uses autoconf. This is not user-visible,
5747 but does simplify configuration and building.
5751 GDB now supports hpux10.
5753 *** Changes in GDB-4.14:
5755 * New native configurations
5757 x86 FreeBSD i[345]86-*-freebsd
5758 x86 NetBSD i[345]86-*-netbsd
5759 NS32k NetBSD ns32k-*-netbsd
5760 Sparc NetBSD sparc-*-netbsd
5764 A29K VxWorks a29k-*-vxworks
5765 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5766 CPU32 EST-300 emulator m68*-*-est*
5767 PowerPC ELF powerpc-*-elf
5770 * Alpha OSF/1 support for procfs
5772 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5773 possible to attach to running processes. As the mounting of the /proc
5774 filesystem is optional on the Alpha, GDB automatically determines
5775 the availability of /proc during startup. This can lead to problems
5776 if /proc is unmounted after GDB has been started.
5778 * Arguments to user-defined commands
5780 User commands may accept up to 10 arguments separated by whitespace.
5781 Arguments are accessed within the user command via $arg0..$arg9. A
5784 print $arg0 + $arg1 + $arg2
5786 To execute the command use:
5789 Defines the command "adder" which prints the sum of its three arguments.
5790 Note the arguments are text substitutions, so they may reference variables,
5791 use complex expressions, or even perform inferior function calls.
5793 * New `if' and `while' commands
5795 This makes it possible to write more sophisticated user-defined
5796 commands. Both commands take a single argument, which is the
5797 expression to evaluate, and must be followed by the commands to
5798 execute, one per line, if the expression is nonzero, the list being
5799 terminated by the word `end'. The `if' command list may include an
5800 `else' word, which causes the following commands to be executed only
5801 if the expression is zero.
5803 * Fortran source language mode
5805 GDB now includes partial support for Fortran 77. It will recognize
5806 Fortran programs and can evaluate a subset of Fortran expressions, but
5807 variables and functions may not be handled correctly. GDB will work
5808 with G77, but does not yet know much about symbols emitted by other
5811 * Better HPUX support
5813 Most debugging facilities now work on dynamic executables for HPPAs
5814 running hpux9 or later. You can attach to running dynamically linked
5815 processes, but by default the dynamic libraries will be read-only, so
5816 for instance you won't be able to put breakpoints in them. To change
5817 that behavior do the following before running the program:
5823 This will cause the libraries to be mapped private and read-write.
5824 To revert to the normal behavior, do this:
5830 You cannot set breakpoints or examine data in the library until after
5831 the library is loaded if the function/data symbols do not have
5834 GDB can now also read debug symbols produced by the HP C compiler on
5835 HPPAs (sorry, no C++, Fortran or 68k support).
5837 * Target byte order now dynamically selectable
5839 You can choose which byte order to use with a target system, via the
5840 commands "set endian big" and "set endian little", and you can see the
5841 current setting by using "show endian". You can also give the command
5842 "set endian auto", in which case GDB will use the byte order
5843 associated with the executable. Currently, only embedded MIPS
5844 configurations support dynamic selection of target byte order.
5846 * New DOS host serial code
5848 This version uses DPMI interrupts to handle buffered I/O, so you
5849 no longer need to run asynctsr when debugging boards connected to
5852 *** Changes in GDB-4.13:
5854 * New "complete" command
5856 This lists all the possible completions for the rest of the line, if it
5857 were to be given as a command itself. This is intended for use by emacs.
5859 * Trailing space optional in prompt
5861 "set prompt" no longer adds a space for you after the prompt you set. This
5862 allows you to set a prompt which ends in a space or one that does not.
5864 * Breakpoint hit counts
5866 "info break" now displays a count of the number of times the breakpoint
5867 has been hit. This is especially useful in conjunction with "ignore"; you
5868 can ignore a large number of breakpoint hits, look at the breakpoint info
5869 to see how many times the breakpoint was hit, then run again, ignoring one
5870 less than that number, and this will get you quickly to the last hit of
5873 * Ability to stop printing at NULL character
5875 "set print null-stop" will cause GDB to stop printing the characters of
5876 an array when the first NULL is encountered. This is useful when large
5877 arrays actually contain only short strings.
5879 * Shared library breakpoints
5881 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5882 breakpoints in shared libraries before the executable is run.
5884 * Hardware watchpoints
5886 There is a new hardware breakpoint for the watch command for sparclite
5887 targets. See gdb/sparclite/hw_breakpoint.note.
5889 Hardware watchpoints are also now supported under GNU/Linux.
5893 Annotations have been added. These are for use with graphical interfaces,
5894 and are still experimental. Currently only gdba.el uses these.
5896 * Improved Irix 5 support
5898 GDB now works properly with Irix 5.2.
5900 * Improved HPPA support
5902 GDB now works properly with the latest GCC and GAS.
5904 * New native configurations
5906 Sequent PTX4 i[34]86-sequent-ptx4
5907 HPPA running OSF/1 hppa*-*-osf*
5908 Atari TT running SVR4 m68*-*-sysv4*
5909 RS/6000 LynxOS rs6000-*-lynxos*
5913 OS/9000 i[34]86-*-os9k
5914 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5917 * Hitachi SH7000 and E7000-PC ICE support
5919 There is now support for communicating with the Hitachi E7000-PC ICE.
5920 This is available automatically when GDB is configured for the SH.
5924 As usual, a variety of small fixes and improvements, both generic
5925 and configuration-specific. See the ChangeLog for more detail.
5927 *** Changes in GDB-4.12:
5929 * Irix 5 is now supported
5933 GDB-4.12 on the HPPA has a number of changes which make it unable
5934 to debug the output from the currently released versions of GCC and
5935 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5936 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5937 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5940 *** Changes in GDB-4.11:
5942 * User visible changes:
5946 The "set remotedebug" option is now consistent between the mips remote
5947 target, remote targets using the gdb-specific protocol, UDI (AMD's
5948 debug protocol for the 29k) and the 88k bug monitor. It is now an
5949 integer specifying a debug level (normally 0 or 1, but 2 means more
5950 debugging info for the mips target).
5952 * DEC Alpha native support
5954 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5955 debug info, but GDB works fairly well with the DEC compiler and should
5956 work with a future GCC release. See the README file for a few
5957 Alpha-specific notes.
5959 * Preliminary thread implementation
5961 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5963 * LynxOS native and target support for 386
5965 This release has been hosted on LynxOS 2.2, and also can be configured
5966 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5969 * Improvements in C++ mangling/demangling.
5971 This release has much better g++ debugging, specifically in name
5972 mangling/demangling, virtual function calls, print virtual table,
5973 call methods, ...etc.
5975 *** Changes in GDB-4.10:
5977 * User visible changes:
5979 Remote debugging using the GDB-specific (`target remote') protocol now
5980 supports the `load' command. This is only useful if you have some
5981 other way of getting the stub to the target system, and you can put it
5982 somewhere in memory where it won't get clobbered by the download.
5984 Filename completion now works.
5986 When run under emacs mode, the "info line" command now causes the
5987 arrow to point to the line specified. Also, "info line" prints
5988 addresses in symbolic form (as well as hex).
5990 All vxworks based targets now support a user settable option, called
5991 vxworks-timeout. This option represents the number of seconds gdb
5992 should wait for responses to rpc's. You might want to use this if
5993 your vxworks target is, perhaps, a slow software simulator or happens
5994 to be on the far side of a thin network line.
5998 This release contains support for using a DEC alpha as a GDB host for
5999 cross debugging. Native alpha debugging is not supported yet.
6002 *** Changes in GDB-4.9:
6006 This is the first GDB release which is accompanied by a matching testsuite.
6007 The testsuite requires installation of dejagnu, which should be available
6008 via ftp from most sites that carry GNU software.
6012 'Cfront' style demangling has had its name changed to 'ARM' style, to
6013 emphasize that it was written from the specifications in the C++ Annotated
6014 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6015 disclaimers, it still generated too much confusion with users attempting to
6016 use gdb with AT&T cfront.
6020 GDB now uses a standard remote interface to a simulator library.
6021 So far, the library contains simulators for the Zilog Z8001/2, the
6022 Hitachi H8/300, H8/500 and Super-H.
6024 * New targets supported
6026 H8/300 simulator h8300-hitachi-hms or h8300hms
6027 H8/500 simulator h8500-hitachi-hms or h8500hms
6028 SH simulator sh-hitachi-hms or sh
6029 Z8000 simulator z8k-zilog-none or z8ksim
6030 IDT MIPS board over serial line mips-idt-ecoff
6032 Cross-debugging to GO32 targets is supported. It requires a custom
6033 version of the i386-stub.c module which is integrated with the
6034 GO32 memory extender.
6036 * New remote protocols
6038 MIPS remote debugging protocol.
6040 * New source languages supported
6042 This version includes preliminary support for Chill, a Pascal like language
6043 used by telecommunications companies. Chill support is also being integrated
6044 into the GNU compiler, but we don't know when it will be publically available.
6047 *** Changes in GDB-4.8:
6049 * HP Precision Architecture supported
6051 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6052 version of this support was available as a set of patches from the
6053 University of Utah. GDB does not support debugging of programs
6054 compiled with the HP compiler, because HP will not document their file
6055 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6056 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6058 Many problems in the preliminary version have been fixed.
6060 * Faster and better demangling
6062 We have improved template demangling and fixed numerous bugs in the GNU style
6063 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6064 character types (wchar_t) are now supported. Demangling of each symbol is now
6065 only done once, and is cached when the symbol table for a file is read in.
6066 This results in a small increase in memory usage for C programs, a moderate
6067 increase in memory usage for C++ programs, and a fantastic speedup in
6070 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6071 from the specifications in the Annotated Reference Manual, which AT&T's
6072 compiler does not actually implement.
6074 * G++ multiple inheritance compiler problem
6076 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6077 inheritance lattices was reworked to properly discover ambiguities. We
6078 recently found an example which causes this new algorithm to fail in a
6079 very subtle way, producing bad debug information for those classes.
6080 The file 'gcc.patch' (in this directory) can be applied to gcc to
6081 circumvent the problem. A future GCC release will contain a complete
6084 The previous G++ debug info problem (mentioned below for the gdb-4.7
6085 release) is fixed in gcc version 2.3.2.
6087 * Improved configure script
6089 The `configure' script will now attempt to guess your system type if
6090 you don't supply a host system type. The old scheme of supplying a
6091 host system triplet is preferable over using this. All the magic is
6092 done in the new `config.guess' script. Examine it for details.
6094 We have also brought our configure script much more in line with the FSF's
6095 version. It now supports the --with-xxx options. In particular,
6096 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6097 The resulting GDB will not be able to read arbitrary object file formats --
6098 only the format ``expected'' to be used on the configured target system.
6099 We hope to make this the default in a future release.
6101 * Documentation improvements
6103 There's new internal documentation on how to modify GDB, and how to
6104 produce clean changes to the code. We implore people to read it
6105 before submitting changes.
6107 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6108 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6109 `info' files are also provided. To build `info' files from scratch,
6110 you will need the latest `makeinfo' release, which will be available in
6111 a future texinfo-X.Y release.
6113 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6114 We're not sure exactly which versions have this problem, but it has
6115 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6116 or better. If that isn't possible, there is a patch in
6117 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6118 around this problem.
6122 GDB now supports array constants that can be used in expressions typed in by
6123 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6124 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6127 The new directory `gdb/sparclite' contains a program that demonstrates
6128 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6130 * New native hosts supported
6132 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6133 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6135 * New targets supported
6137 AMD 29k family via UDI a29k-amd-udi or udi29k
6139 * New file formats supported
6141 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6142 HPUX core files, and SCO 3.2v2 core files.
6146 Attaching to processes now works again; thanks for the many bug reports.
6148 We have also stomped on a bunch of core dumps caused by
6149 printf_filtered("%s") problems.
6151 We eliminated a copyright problem on the rpc and ptrace header files
6152 for VxWorks, which was discovered at the last minute during the 4.7
6153 release. You should now be able to build a VxWorks GDB.
6155 You can now interrupt gdb while an attached process is running. This
6156 will cause the attached process to stop, and give control back to GDB.
6158 We fixed problems caused by using too many file descriptors
6159 for reading symbols from object files and libraries. This was
6160 especially a problem for programs that used many (~100) shared
6163 The `step' command now only enters a subroutine if there is line number
6164 information for the subroutine. Otherwise it acts like the `next'
6165 command. Previously, `step' would enter subroutines if there was
6166 any debugging information about the routine. This avoids problems
6167 when using `cc -g1' on MIPS machines.
6169 * Internal improvements
6171 GDB's internal interfaces have been improved to make it easier to support
6172 debugging of multiple languages in the future.
6174 GDB now uses a common structure for symbol information internally.
6175 Minimal symbols (derived from linkage symbols in object files), partial
6176 symbols (from a quick scan of debug information), and full symbols
6177 contain a common subset of information, making it easier to write
6178 shared code that handles any of them.
6180 * New command line options
6182 We now accept --silent as an alias for --quiet.
6186 The memory-mapped-malloc library is now licensed under the GNU Library
6187 General Public License.
6189 *** Changes in GDB-4.7:
6191 * Host/native/target split
6193 GDB has had some major internal surgery to untangle the support for
6194 hosts and remote targets. Now, when you configure GDB for a remote
6195 target, it will no longer load in all of the support for debugging
6196 local programs on the host. When fully completed and tested, this will
6197 ensure that arbitrary host/target combinations are possible.
6199 The primary conceptual shift is to separate the non-portable code in
6200 GDB into three categories. Host specific code is required any time GDB
6201 is compiled on that host, regardless of the target. Target specific
6202 code relates to the peculiarities of the target, but can be compiled on
6203 any host. Native specific code is everything else: it can only be
6204 built when the host and target are the same system. Child process
6205 handling and core file support are two common `native' examples.
6207 GDB's use of /proc for controlling Unix child processes is now cleaner.
6208 It has been split out into a single module under the `target_ops' vector,
6209 plus two native-dependent functions for each system that uses /proc.
6211 * New hosts supported
6213 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6214 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6215 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6217 * New targets supported
6219 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6220 68030 and CPU32 m68030-*-*, m68332-*-*
6222 * New native hosts supported
6224 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6225 (386bsd is not well tested yet)
6226 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6228 * New file formats supported
6230 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6231 supports reading of `a.out.adobe' object files, which are an a.out
6232 format extended with minimal information about multiple sections.
6236 `show copying' is the same as the old `info copying'.
6237 `show warranty' is the same as `info warrantee'.
6238 These were renamed for consistency. The old commands continue to work.
6240 `info handle' is a new alias for `info signals'.
6242 You can now define pre-command hooks, which attach arbitrary command
6243 scripts to any command. The commands in the hook will be executed
6244 prior to the user's command. You can also create a hook which will be
6245 executed whenever the program stops. See gdb.texinfo.
6249 We now deal with Cfront style name mangling, and can even extract type
6250 info from mangled symbols. GDB can automatically figure out which
6251 symbol mangling style your C++ compiler uses.
6253 Calling of methods and virtual functions has been improved as well.
6257 The crash that occured when debugging Sun Ansi-C compiled binaries is
6258 fixed. This was due to mishandling of the extra N_SO stabs output
6261 We also finally got Ultrix 4.2 running in house, and fixed core file
6262 support, with help from a dozen people on the net.
6264 John M. Farrell discovered that the reason that single-stepping was so
6265 slow on all of the Mips based platforms (primarily SGI and DEC) was
6266 that we were trying to demangle and lookup a symbol used for internal
6267 purposes on every instruction that was being stepped through. Changing
6268 the name of that symbol so that it couldn't be mistaken for a C++
6269 mangled symbol sped things up a great deal.
6271 Rich Pixley sped up symbol lookups in general by getting much smarter
6272 about when C++ symbol mangling is necessary. This should make symbol
6273 completion (TAB on the command line) much faster. It's not as fast as
6274 we'd like, but it's significantly faster than gdb-4.6.
6278 A new user controllable variable 'call_scratch_address' can
6279 specify the location of a scratch area to be used when GDB
6280 calls a function in the target. This is necessary because the
6281 usual method of putting the scratch area on the stack does not work
6282 in systems that have separate instruction and data spaces.
6284 We integrated changes to support the 29k UDI (Universal Debugger
6285 Interface), but discovered at the last minute that we didn't have all
6286 of the appropriate copyright paperwork. We are working with AMD to
6287 resolve this, and hope to have it available soon.
6291 We have sped up the remote serial line protocol, especially for targets
6292 with lots of registers. It now supports a new `expedited status' ('T')
6293 message which can be used in place of the existing 'S' status message.
6294 This allows the remote stub to send only the registers that GDB
6295 needs to make a quick decision about single-stepping or conditional
6296 breakpoints, eliminating the need to fetch the entire register set for
6297 each instruction being stepped through.
6299 The GDB remote serial protocol now implements a write-through cache for
6300 registers, only re-reading the registers if the target has run.
6302 There is also a new remote serial stub for SPARC processors. You can
6303 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6304 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6305 processor with a serial port.
6309 Configure.in files have become much easier to read and modify. A new
6310 `table driven' format makes it more obvious what configurations are
6311 supported, and what files each one uses.
6315 There is a new opcodes library which will eventually contain all of the
6316 disassembly routines and opcode tables. At present, it only contains
6317 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6318 disassembler (binutils/objdump) to share these routines.
6320 The libiberty library is now copylefted under the GNU Library General
6321 Public License. This allows more liberal use, and was done so libg++
6322 can use it. This makes no difference to GDB, since the Library License
6323 grants all the rights from the General Public License.
6327 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6328 reference to the stabs symbol info used by the debugger. It is (as far
6329 as we know) the only published document on this fascinating topic. We
6330 encourage you to read it, compare it to the stabs information on your
6331 system, and send improvements on the document in general (to
6332 bug-gdb@prep.ai.mit.edu).
6334 And, of course, many bugs have been fixed.
6337 *** Changes in GDB-4.6:
6339 * Better support for C++ function names
6341 GDB now accepts as input the "demangled form" of C++ overloaded function
6342 names and member function names, and can do command completion on such names
6343 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6344 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6345 Make use of command completion, it is your friend.
6347 GDB also now accepts a variety of C++ mangled symbol formats. They are
6348 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6349 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6350 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6351 for the list of formats.
6353 * G++ symbol mangling problem
6355 Recent versions of gcc have a bug in how they emit debugging information for
6356 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6357 directory) can be applied to gcc to fix the problem. Alternatively, if you
6358 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6359 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6360 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6363 * New 'maintenance' command
6365 All of the commands related to hacking GDB internals have been moved out of
6366 the main command set, and now live behind the 'maintenance' command. This
6367 can also be abbreviated as 'mt'. The following changes were made:
6369 dump-me -> maintenance dump-me
6370 info all-breakpoints -> maintenance info breakpoints
6371 printmsyms -> maintenance print msyms
6372 printobjfiles -> maintenance print objfiles
6373 printpsyms -> maintenance print psymbols
6374 printsyms -> maintenance print symbols
6376 The following commands are new:
6378 maintenance demangle Call internal GDB demangler routine to
6379 demangle a C++ link name and prints the result.
6380 maintenance print type Print a type chain for a given symbol
6382 * Change to .gdbinit file processing
6384 We now read the $HOME/.gdbinit file before processing the argv arguments
6385 (e.g. reading symbol files or core files). This allows global parameters to
6386 be set, which will apply during the symbol reading. The ./.gdbinit is still
6387 read after argv processing.
6389 * New hosts supported
6391 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6393 GNU/Linux support i386-unknown-linux or linux
6395 We are also including code to support the HP/PA running BSD and HPUX. This
6396 is almost guaranteed not to work, as we didn't have time to test or build it
6397 for this release. We are including it so that the more adventurous (or
6398 masochistic) of you can play with it. We also had major problems with the
6399 fact that the compiler that we got from HP doesn't support the -g option.
6402 * New targets supported
6404 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6406 * More smarts about finding #include files
6408 GDB now remembers the compilation directory for all include files, and for
6409 all files from which C is generated (like yacc and lex sources). This
6410 greatly improves GDB's ability to find yacc/lex sources, and include files,
6411 especially if you are debugging your program from a directory different from
6412 the one that contains your sources.
6414 We also fixed a bug which caused difficulty with listing and setting
6415 breakpoints in include files which contain C code. (In the past, you had to
6416 try twice in order to list an include file that you hadn't looked at before.)
6418 * Interesting infernals change
6420 GDB now deals with arbitrary numbers of sections, where the symbols for each
6421 section must be relocated relative to that section's landing place in the
6422 target's address space. This work was needed to support ELF with embedded
6423 stabs used by Solaris-2.0.
6425 * Bug fixes (of course!)
6427 There have been loads of fixes for the following things:
6428 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6429 i960, stabs, DOS(GO32), procfs, etc...
6431 See the ChangeLog for details.
6433 *** Changes in GDB-4.5:
6435 * New machines supported (host and target)
6437 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6439 SGI Irix-4.x mips-sgi-irix4 or iris4
6441 * New malloc package
6443 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6444 Mmalloc is capable of handling mutiple heaps of memory. It is also
6445 capable of saving a heap to a file, and then mapping it back in later.
6446 This can be used to greatly speedup the startup of GDB by using a
6447 pre-parsed symbol table which lives in a mmalloc managed heap. For
6448 more details, please read mmalloc/mmalloc.texi.
6452 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6453 'help info proc' for details.
6455 * MIPS ecoff symbol table format
6457 The code that reads MIPS symbol table format is now supported on all hosts.
6458 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6461 * File name changes for MS-DOS
6463 Many files in the config directories have been renamed to make it easier to
6464 support GDB on MS-DOSe systems (which have very restrictive file name
6465 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6466 environment) is close to working but has some remaining problems. Note
6467 that debugging of DOS programs is not supported, due to limitations
6468 in the ``operating system'', but it can be used to host cross-debugging.
6470 * Cross byte order fixes
6472 Many fixes have been made to support cross debugging of Sparc and MIPS
6473 targets from hosts whose byte order differs.
6475 * New -mapped and -readnow options
6477 If memory-mapped files are available on your system through the 'mmap'
6478 system call, you can use the -mapped option on the `file' or
6479 `symbol-file' commands to cause GDB to write the symbols from your
6480 program into a reusable file. If the program you are debugging is
6481 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6482 Future GDB debugging sessions will notice the presence of this file,
6483 and will quickly map in symbol information from it, rather than reading
6484 the symbol table from the executable program. Using the '-mapped'
6485 option in a GDB `file' or `symbol-file' command has the same effect as
6486 starting GDB with the '-mapped' command-line option.
6488 You can cause GDB to read the entire symbol table immediately by using
6489 the '-readnow' option with any of the commands that load symbol table
6490 information (or on the GDB command line). This makes the command
6491 slower, but makes future operations faster.
6493 The -mapped and -readnow options are typically combined in order to
6494 build a `fred.syms' file that contains complete symbol information.
6495 A simple GDB invocation to do nothing but build a `.syms' file for future
6498 gdb -batch -nx -mapped -readnow programname
6500 The `.syms' file is specific to the host machine on which GDB is run.
6501 It holds an exact image of GDB's internal symbol table. It cannot be
6502 shared across multiple host platforms.
6504 * longjmp() handling
6506 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6507 siglongjmp() without losing control. This feature has not yet been ported to
6508 all systems. It currently works on many 386 platforms, all MIPS-based
6509 platforms (SGI, DECstation, etc), and Sun3/4.
6513 Preliminary work has been put in to support the new Solaris OS from Sun. At
6514 this time, it can control and debug processes, but it is not capable of
6519 As always, many many bug fixes. The major areas were with g++, and mipsread.
6520 People using the MIPS-based platforms should experience fewer mysterious
6521 crashes and trashed symbol tables.
6523 *** Changes in GDB-4.4:
6525 * New machines supported (host and target)
6527 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6529 BSD Reno on Vax vax-dec-bsd
6530 Ultrix on Vax vax-dec-ultrix
6532 * New machines supported (target)
6534 AMD 29000 embedded, using EBMON a29k-none-none
6538 GDB continues to improve its handling of C++. `References' work better.
6539 The demangler has also been improved, and now deals with symbols mangled as
6540 per the Annotated C++ Reference Guide.
6542 GDB also now handles `stabs' symbol information embedded in MIPS
6543 `ecoff' symbol tables. Since the ecoff format was not easily
6544 extensible to handle new languages such as C++, this appeared to be a
6545 good way to put C++ debugging info into MIPS binaries. This option
6546 will be supported in the GNU C compiler, version 2, when it is
6549 * New features for SVR4
6551 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6552 shared libraries. Debugging dynamically linked programs should present
6553 only minor differences from debugging statically linked programs.
6555 The `info proc' command will print out information about any process
6556 on an SVR4 system (including the one you are debugging). At the moment,
6557 it prints the address mappings of the process.
6559 If you bring up GDB on another SVR4 system, please send mail to
6560 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6562 * Better dynamic linking support in SunOS
6564 Reading symbols from shared libraries which contain debugging symbols
6565 now works properly. However, there remain issues such as automatic
6566 skipping of `transfer vector' code during function calls, which
6567 make it harder to debug code in a shared library, than to debug the
6568 same code linked statically.
6572 GDB is now using the latest `getopt' routines from the FSF. This
6573 version accepts the -- prefix for options with long names. GDB will
6574 continue to accept the old forms (-option and +option) as well.
6575 Various single letter abbreviations for options have been explicity
6576 added to the option table so that they won't get overshadowed in the
6577 future by other options that begin with the same letter.
6581 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6582 Many assorted bugs have been handled. Many more remain to be handled.
6583 See the various ChangeLog files (primarily in gdb and bfd) for details.
6586 *** Changes in GDB-4.3:
6588 * New machines supported (host and target)
6590 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6591 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6592 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6594 * Almost SCO Unix support
6596 We had hoped to support:
6597 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6598 (except for core file support), but we discovered very late in the release
6599 that it has problems with process groups that render gdb unusable. Sorry
6600 about that. I encourage people to fix it and post the fixes.
6602 * Preliminary ELF and DWARF support
6604 GDB can read ELF object files on System V Release 4, and can handle
6605 debugging records for C, in DWARF format, in ELF files. This support
6606 is preliminary. If you bring up GDB on another SVR4 system, please
6607 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6612 GDB now uses the latest `readline' library. One user-visible change
6613 is that two tabs will list possible command completions, which previously
6614 required typing M-? (meta-question mark, or ESC ?).
6618 The `stepi' bug that many of you noticed has been squashed.
6619 Many bugs in C++ have been handled. Many more remain to be handled.
6620 See the various ChangeLog files (primarily in gdb and bfd) for details.
6622 * State of the MIPS world (in case you wondered):
6624 GDB can understand the symbol tables emitted by the compilers
6625 supplied by most vendors of MIPS-based machines, including DEC. These
6626 symbol tables are in a format that essentially nobody else uses.
6628 Some versions of gcc come with an assembler post-processor called
6629 mips-tfile. This program is required if you want to do source-level
6630 debugging of gcc-compiled programs. I believe FSF does not ship
6631 mips-tfile with gcc version 1, but it will eventually come with gcc
6634 Debugging of g++ output remains a problem. g++ version 1.xx does not
6635 really support it at all. (If you're lucky, you should be able to get
6636 line numbers and stack traces to work, but no parameters or local
6637 variables.) With some work it should be possible to improve the
6640 When gcc version 2 is released, you will have somewhat better luck.
6641 However, even then you will get confusing results for inheritance and
6644 We will eventually provide full debugging of g++ output on
6645 DECstations. This will probably involve some kind of stabs-in-ecoff
6646 encapulation, but the details have not been worked out yet.
6649 *** Changes in GDB-4.2:
6651 * Improved configuration
6653 Only one copy of `configure' exists now, and it is not self-modifying.
6654 Porting BFD is simpler.
6658 The `step' and `next' commands now only stop at the first instruction
6659 of a source line. This prevents the multiple stops that used to occur
6660 in switch statements, for-loops, etc. `Step' continues to stop if a
6661 function that has debugging information is called within the line.
6665 Lots of small bugs fixed. More remain.
6667 * New host supported (not target)
6669 Intel 386 PC clone running Mach i386-none-mach
6672 *** Changes in GDB-4.1:
6674 * Multiple source language support
6676 GDB now has internal scaffolding to handle several source languages.
6677 It determines the type of each source file from its filename extension,
6678 and will switch expression parsing and number formatting to match the
6679 language of the function in the currently selected stack frame.
6680 You can also specifically set the language to be used, with
6681 `set language c' or `set language modula-2'.
6685 GDB now has preliminary support for the GNU Modula-2 compiler,
6686 currently under development at the State University of New York at
6687 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6688 continue through the fall of 1991 and into 1992.
6690 Other Modula-2 compilers are currently not supported, and attempting to
6691 debug programs compiled with them will likely result in an error as the
6692 symbol table is read. Feel free to work on it, though!
6694 There are hooks in GDB for strict type checking and range checking,
6695 in the `Modula-2 philosophy', but they do not currently work.
6699 GDB can now write to executable and core files (e.g. patch
6700 a variable's value). You must turn this switch on, specify
6701 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6702 by assigning a new value to a variable. Modifications take
6705 * Automatic SunOS shared library reading
6707 When you run your program, GDB automatically determines where its
6708 shared libraries (if any) have been loaded, and reads their symbols.
6709 The `share' command is no longer needed. This also works when
6710 examining core files.
6714 You can specify the number of lines that the `list' command shows.
6717 * New machines supported (host and target)
6719 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6720 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6721 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6723 * New hosts supported (not targets)
6725 IBM RT/PC: romp-ibm-aix or rtpc
6727 * New targets supported (not hosts)
6729 AMD 29000 embedded with COFF a29k-none-coff
6730 AMD 29000 embedded with a.out a29k-none-aout
6731 Ultracomputer remote kernel debug a29k-nyu-kern
6733 * New remote interfaces
6739 *** Changes in GDB-4.0:
6743 Wide output is wrapped at good places to make the output more readable.
6745 Gdb now supports cross-debugging from a host machine of one type to a
6746 target machine of another type. Communication with the target system
6747 is over serial lines. The ``target'' command handles connecting to the
6748 remote system; the ``load'' command will download a program into the
6749 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6750 also supports debugging of realtime processes running under VxWorks,
6751 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6752 stub on the target system.
6754 New CPUs supported include the AMD 29000 and Intel 960.
6756 GDB now reads object files and symbol tables via a ``binary file''
6757 library, which allows a single copy of GDB to debug programs of multiple
6758 object file types such as a.out and coff.
6760 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6761 refcard.dvi and refcard.ps are available to format it).
6764 * Control-Variable user interface simplified
6766 All variables that control the operation of the debugger can be set
6767 by the ``set'' command, and displayed by the ``show'' command.
6769 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6770 ``Show prompt'' produces the response:
6771 Gdb's prompt is new-gdb=>.
6773 What follows are the NEW set commands. The command ``help set'' will
6774 print a complete list of old and new set commands. ``help set FOO''
6775 will give a longer description of the variable FOO. ``show'' will show
6776 all of the variable descriptions and their current settings.
6778 confirm on/off: Enables warning questions for operations that are
6779 hard to recover from, e.g. rerunning the program while
6780 it is already running. Default is ON.
6782 editing on/off: Enables EMACS style command line editing
6783 of input. Previous lines can be recalled with
6784 control-P, the current line can be edited with control-B,
6785 you can search for commands with control-R, etc.
6788 history filename NAME: NAME is where the gdb command history
6789 will be stored. The default is .gdb_history,
6790 or the value of the environment variable
6793 history size N: The size, in commands, of the command history. The
6794 default is 256, or the value of the environment variable
6797 history save on/off: If this value is set to ON, the history file will
6798 be saved after exiting gdb. If set to OFF, the
6799 file will not be saved. The default is OFF.
6801 history expansion on/off: If this value is set to ON, then csh-like
6802 history expansion will be performed on
6803 command line input. The default is OFF.
6805 radix N: Sets the default radix for input and output. It can be set
6806 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6807 in the current radix, so "set radix 10" is always a no-op.
6809 height N: This integer value is the number of lines on a page. Default
6810 is 24, the current `stty rows'' setting, or the ``li#''
6811 setting from the termcap entry matching the environment
6814 width N: This integer value is the number of characters on a line.
6815 Default is 80, the current `stty cols'' setting, or the ``co#''
6816 setting from the termcap entry matching the environment
6819 Note: ``set screensize'' is obsolete. Use ``set height'' and
6820 ``set width'' instead.
6822 print address on/off: Print memory addresses in various command displays,
6823 such as stack traces and structure values. Gdb looks
6824 more ``symbolic'' if you turn this off; it looks more
6825 ``machine level'' with it on. Default is ON.
6827 print array on/off: Prettyprint arrays. New convenient format! Default
6830 print demangle on/off: Print C++ symbols in "source" form if on,
6833 print asm-demangle on/off: Same, for assembler level printouts
6836 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6839 * Support for Epoch Environment.
6841 The epoch environment is a version of Emacs v18 with windowing. One
6842 new command, ``inspect'', is identical to ``print'', except that if you
6843 are running in the epoch environment, the value is printed in its own
6847 * Support for Shared Libraries
6849 GDB can now debug programs and core files that use SunOS shared libraries.
6850 Symbols from a shared library cannot be referenced
6851 before the shared library has been linked with the program (this
6852 happens after you type ``run'' and before the function main() is entered).
6853 At any time after this linking (including when examining core files
6854 from dynamically linked programs), gdb reads the symbols from each
6855 shared library when you type the ``sharedlibrary'' command.
6856 It can be abbreviated ``share''.
6858 sharedlibrary REGEXP: Load shared object library symbols for files
6859 matching a unix regular expression. No argument
6860 indicates to load symbols for all shared libraries.
6862 info sharedlibrary: Status of loaded shared libraries.
6867 A watchpoint stops execution of a program whenever the value of an
6868 expression changes. Checking for this slows down execution
6869 tremendously whenever you are in the scope of the expression, but is
6870 quite useful for catching tough ``bit-spreader'' or pointer misuse
6871 problems. Some machines such as the 386 have hardware for doing this
6872 more quickly, and future versions of gdb will use this hardware.
6874 watch EXP: Set a watchpoint (breakpoint) for an expression.
6876 info watchpoints: Information about your watchpoints.
6878 delete N: Deletes watchpoint number N (same as breakpoints).
6879 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6880 enable N: Re-enables watchpoint number N (same as breakpoints).
6883 * C++ multiple inheritance
6885 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6888 * C++ exception handling
6890 Gdb now supports limited C++ exception handling. Besides the existing
6891 ability to breakpoint on an exception handler, gdb can breakpoint on
6892 the raising of an exception (before the stack is peeled back to the
6895 catch FOO: If there is a FOO exception handler in the dynamic scope,
6896 set a breakpoint to catch exceptions which may be raised there.
6897 Multiple exceptions (``catch foo bar baz'') may be caught.
6899 info catch: Lists all exceptions which may be caught in the
6900 current stack frame.
6903 * Minor command changes
6905 The command ``call func (arg, arg, ...)'' now acts like the print
6906 command, except it does not print or save a value if the function's result
6907 is void. This is similar to dbx usage.
6909 The ``up'' and ``down'' commands now always print the frame they end up
6910 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6911 frames without printing.
6913 * New directory command
6915 'dir' now adds directories to the FRONT of the source search path.
6916 The path starts off empty. Source files that contain debug information
6917 about the directory in which they were compiled can be found even
6918 with an empty path; Sun CC and GCC include this information. If GDB can't
6919 find your source file in the current directory, type "dir .".
6921 * Configuring GDB for compilation
6923 For normal use, type ``./configure host''. See README or gdb.texinfo
6926 GDB now handles cross debugging. If you are remotely debugging between
6927 two different machines, type ``./configure host -target=targ''.
6928 Host is the machine where GDB will run; targ is the machine
6929 where the program that you are debugging will run.
projects / external / binutils.git / blob