1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.1
6 * The 'symbol-file' command now accepts an '-o' option to add a relative
7 offset to all sections.
9 * The endianness used with the 'set endian auto' mode in the absence of
10 an executable selected for debugging is now the last endianness chosen
11 either by one of the 'set endian big' and 'set endian little' commands
12 or by inferring from the last executable used, rather than the startup
15 * The pager now allows a "c" response, meaning to disable the pager
16 for the rest of the current command.
18 * The commands 'info variables/functions/types' now show the source line
19 numbers of symbol definitions when available.
21 * 'info proc' now works on running processes on FreeBSD systems and core
22 files created on FreeBSD systems.
24 * C expressions can now use _Alignof, and C++ expressions can now use
31 Control display of debugging info regarding the FreeBSD native target.
33 set|show varsize-limit
34 This new setting allows the user to control the maximum size of Ada
35 objects being printed when those objects have a variable type,
36 instead of that maximum size being hardcoded to 65536 bytes.
38 set|show record btrace cpu
39 Controls the processor to be used for enabling errata workarounds for
42 maint check libthread-db
43 Run integrity checks on the current inferior's thread debugging
46 maint set check-libthread-db (on|off)
47 maint show check-libthread-db
48 Control whether to run integrity checks on inferior specific thread
49 debugging libraries as they are loaded. The default is not to
54 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
56 ** The commands attached to a breakpoint can be set by assigning to
57 the breakpoint's "commands" field.
59 ** gdb.execute can now execute multi-line gdb commands.
61 ** The new functions gdb.convenience_variable and
62 gdb.set_convenience_variable can be used to get and set the value
63 of convenience variables.
65 ** A gdb.Parameter will no longer print the "set" help text on an
66 ordinary "set"; instead by default a "set" will be silent unless
67 the get_set_string method returns a non-empty string.
71 RiscV ELF riscv*-*-elf
73 * Removed targets and native configurations
75 m88k running OpenBSD m88*-*-openbsd*
76 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
77 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
78 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
80 * Aarch64/Linux hardware watchpoints improvements
82 Hardware watchpoints on unaligned addresses are now properly
83 supported when running Linux kernel 4.10 or higher: read and access
84 watchpoints are no longer spuriously missed, and all watchpoints
85 lengths between 1 and 8 bytes are supported. On older kernels,
86 watchpoints set on unaligned addresses are no longer missed, with
87 the tradeoff that there is a possibility of false hits being
90 *** Changes in GDB 8.1
92 * GDB now supports dynamically creating arbitrary register groups specified
93 in XML target descriptions. This allows for finer grain grouping of
94 registers on systems with a large amount of registers.
96 * The 'ptype' command now accepts a '/o' flag, which prints the
97 offsets and sizes of fields in a struct, like the pahole(1) tool.
99 * New "--readnever" command line option instructs GDB to not read each
100 symbol file's symbolic debug information. This makes startup faster
101 but at the expense of not being able to perform symbolic debugging.
102 This option is intended for use cases where symbolic debugging will
103 not be used, e.g., when you only need to dump the debuggee's core.
105 * GDB now uses the GNU MPFR library, if available, to emulate target
106 floating-point arithmetic during expression evaluation when the target
107 uses different floating-point formats than the host. At least version
108 3.1 of GNU MPFR is required.
110 * GDB now supports access to the guarded-storage-control registers and the
111 software-based guarded-storage broadcast control registers on IBM z14.
113 * On Unix systems, GDB now supports transmitting environment variables
114 that are to be set or unset to GDBserver. These variables will
115 affect the environment to be passed to the remote inferior.
117 To inform GDB of environment variables that are to be transmitted to
118 GDBserver, use the "set environment" command. Only user set
119 environment variables are sent to GDBserver.
121 To inform GDB of environment variables that are to be unset before
122 the remote inferior is started by the GDBserver, use the "unset
123 environment" command.
125 * Completion improvements
127 ** GDB can now complete function parameters in linespecs and
128 explicit locations without quoting. When setting breakpoints,
129 quoting around functions names to help with TAB-completion is
130 generally no longer necessary. For example, this now completes
133 (gdb) b function(in[TAB]
134 (gdb) b function(int)
136 Related, GDB is no longer confused with completing functions in
137 C++ anonymous namespaces:
140 (gdb) b (anonymous namespace)::[TAB][TAB]
141 (anonymous namespace)::a_function()
142 (anonymous namespace)::b_function()
144 ** GDB now has much improved linespec and explicit locations TAB
145 completion support, that better understands what you're
146 completing and offers better suggestions. For example, GDB no
147 longer offers data symbols as possible completions when you're
148 setting a breakpoint.
150 ** GDB now TAB-completes label symbol names.
152 ** The "complete" command now mimics TAB completion accurately.
154 * New command line options (gcore)
157 Dump all memory mappings.
159 * Breakpoints on C++ functions are now set on all scopes by default
161 By default, breakpoints on functions/methods are now interpreted as
162 specifying all functions with the given name ignoring missing
163 leading scopes (namespaces and classes).
165 For example, assuming a C++ program with symbols named:
170 both commands "break func()" and "break B::func()" set a breakpoint
173 You can use the new flag "-qualified" to override this. This makes
174 GDB interpret the specified function name as a complete
175 fully-qualified name instead. For example, using the same C++
176 program, the "break -q B::func" command sets a breakpoint on
177 "B::func", only. A parameter has been added to the Python
178 gdb.Breakpoint constructor to achieve the same result when creating
179 a breakpoint from Python.
181 * Breakpoints on functions marked with C++ ABI tags
183 GDB can now set breakpoints on functions marked with C++ ABI tags
184 (e.g., [abi:cxx11]). See here for a description of ABI tags:
185 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
187 Functions with a C++11 abi tag are demangled/displayed like this:
189 function[abi:cxx11](int)
192 You can now set a breakpoint on such functions simply as if they had
195 (gdb) b function(int)
197 Or if you need to disambiguate between tags, like:
199 (gdb) b function[abi:other_tag](int)
201 Tab completion was adjusted accordingly as well.
205 ** New events gdb.new_inferior, gdb.inferior_deleted, and
206 gdb.new_thread are emitted. See the manual for further
207 description of these.
209 ** A new function, "gdb.rbreak" has been added to the Python API.
210 This function allows the setting of a large number of breakpoints
211 via a regex pattern in Python. See the manual for further details.
213 ** Python breakpoints can now accept explicit locations. See the
214 manual for a further description of this feature.
217 * New features in the GDB remote stub, GDBserver
219 ** GDBserver is now able to start inferior processes with a
220 specified initial working directory.
222 The user can set the desired working directory to be used from
223 GDB using the new "set cwd" command.
225 ** New "--selftest" command line option runs some GDBserver self
226 tests. These self tests are disabled in releases.
228 ** On Unix systems, GDBserver now does globbing expansion and variable
229 substitution in inferior command line arguments.
231 This is done by starting inferiors using a shell, like GDB does.
232 See "set startup-with-shell" in the user manual for how to disable
233 this from GDB when using "target extended-remote". When using
234 "target remote", you can disable the startup with shell by using the
235 new "--no-startup-with-shell" GDBserver command line option.
237 ** On Unix systems, GDBserver now supports receiving environment
238 variables that are to be set or unset from GDB. These variables
239 will affect the environment to be passed to the inferior.
241 * When catching an Ada exception raised with a message, GDB now prints
242 the message in the catchpoint hit notification. In GDB/MI mode, that
243 information is provided as an extra field named "exception-message"
244 in the *stopped notification.
246 * Trait objects can now be inspected When debugging Rust code. This
247 requires compiler support which will appear in Rust 1.24.
251 QEnvironmentHexEncoded
252 Inform GDBserver of an environment variable that is to be passed to
253 the inferior when starting it.
256 Inform GDBserver of an environment variable that is to be unset
257 before starting the remote inferior.
260 Inform GDBserver that the environment should be reset (i.e.,
261 user-set environment variables should be unset).
264 Indicates whether the inferior must be started with a shell or not.
267 Tell GDBserver that the inferior to be started should use a specific
270 * The "maintenance print c-tdesc" command now takes an optional
271 argument which is the file name of XML target description.
273 * The "maintenance selftest" command now takes an optional argument to
274 filter the tests to be run.
276 * The "enable", and "disable" commands now accept a range of
277 breakpoint locations, e.g. "enable 1.3-5".
282 Set and show the current working directory for the inferior.
285 Set and show compilation command used for compiling and injecting code
286 with the 'compile' commands.
288 set debug separate-debug-file
289 show debug separate-debug-file
290 Control the display of debug output about separate debug file search.
292 set dump-excluded-mappings
293 show dump-excluded-mappings
294 Control whether mappings marked with the VM_DONTDUMP flag should be
295 dumped when generating a core file.
298 List the registered selftests.
301 Start the debugged program stopping at the first instruction.
304 Control display of debugging messages related to OpenRISC targets.
306 set|show print type nested-type-limit
307 Set and show the limit of nesting level for nested types that the
308 type printer will show.
310 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
313 * Safer/improved support for debugging with no debug info
315 GDB no longer assumes functions with no debug information return
318 This means that GDB now refuses to call such functions unless you
319 tell it the function's type, by either casting the call to the
320 declared return type, or by casting the function to a function
321 pointer of the right type, and calling that:
323 (gdb) p getenv ("PATH")
324 'getenv' has unknown return type; cast the call to its declared return type
325 (gdb) p (char *) getenv ("PATH")
326 $1 = 0x7fffffffe "/usr/local/bin:/"...
327 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
328 $2 = 0x7fffffffe "/usr/local/bin:/"...
330 Similarly, GDB no longer assumes that global variables with no debug
331 info have type 'int', and refuses to print the variable's value
332 unless you tell it the variable's type:
335 'var' has unknown type; cast it to its declared type
339 * New native configurations
341 FreeBSD/aarch64 aarch64*-*-freebsd*
342 FreeBSD/arm arm*-*-freebsd*
346 FreeBSD/aarch64 aarch64*-*-freebsd*
347 FreeBSD/arm arm*-*-freebsd*
348 OpenRISC ELF or1k*-*-elf
350 * Removed targets and native configurations
352 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
354 *** Changes in GDB 8.0
356 * GDB now supports access to the PKU register on GNU/Linux. The register is
357 added by the Memory Protection Keys for Userspace feature which will be
358 available in future Intel CPUs.
360 * GDB now supports C++11 rvalue references.
364 ** New functions to start, stop and access a running btrace recording.
365 ** Rvalue references are now supported in gdb.Type.
367 * GDB now supports recording and replaying rdrand and rdseed Intel 64
370 * Building GDB and GDBserver now requires a C++11 compiler.
372 For example, GCC 4.8 or later.
374 It is no longer possible to build GDB or GDBserver with a C
375 compiler. The --disable-build-with-cxx configure option has been
378 * Building GDB and GDBserver now requires GNU make >= 3.81.
380 It is no longer supported to build GDB or GDBserver with another
381 implementation of the make program or an earlier version of GNU make.
383 * Native debugging on MS-Windows supports command-line redirection
385 Command-line arguments used for starting programs on MS-Windows can
386 now include redirection symbols supported by native Windows shells,
387 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
388 as "run", "start", and "set args", as well as the corresponding MI
391 * Support for thread names on MS-Windows.
393 GDB now catches and handles the special exception that programs
394 running on MS-Windows use to assign names to threads in the
397 * Support for Java programs compiled with gcj has been removed.
399 * User commands now accept an unlimited number of arguments.
400 Previously, only up to 10 was accepted.
402 * The "eval" command now expands user-defined command arguments.
404 This makes it easier to process a variable number of arguments:
409 eval "print $arg%d", $i
414 * Target descriptions can now describe registers for sparc32 and sparc64.
416 * GDB now supports DWARF version 5 (debug information format).
417 Its .debug_names index is not yet supported.
419 * New native configurations
421 FreeBSD/mips mips*-*-freebsd
425 Synopsys ARC arc*-*-elf32
426 FreeBSD/mips mips*-*-freebsd
428 * Removed targets and native configurations
430 Alpha running FreeBSD alpha*-*-freebsd*
431 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
436 Erases all the flash memory regions reported by the target.
438 maint print arc arc-instruction address
439 Print internal disassembler information about instruction at a given address.
443 set disassembler-options
444 show disassembler-options
445 Controls the passing of target specific information to the disassembler.
446 If it is necessary to specify more than one disassembler option then
447 multiple options can be placed together into a comma separated list.
448 The default value is the empty string. Currently, the only supported
449 targets are ARM, PowerPC and S/390.
454 Erases all the flash memory regions reported by the target. This is
455 equivalent to the CLI command flash-erase.
457 -file-list-shared-libraries
458 List the shared libraries in the program. This is
459 equivalent to the CLI command "info shared".
462 Catchpoints stopping the program when Ada exceptions are
463 handled. This is equivalent to the CLI command "catch handlers".
465 *** Changes in GDB 7.12
467 * GDB and GDBserver now build with a C++ compiler by default.
469 The --enable-build-with-cxx configure option is now enabled by
470 default. One must now explicitly configure with
471 --disable-build-with-cxx in order to build with a C compiler. This
472 option will be removed in a future release.
474 * GDBserver now supports recording btrace without maintaining an active
477 * GDB now supports a negative repeat count in the 'x' command to examine
478 memory backward from the given address. For example:
481 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
482 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
483 (gdb) x/-5i 0x0000000000400580
484 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
485 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
486 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
487 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
488 0x40057b <main(int, char**)+25>:
489 callq 0x400536 <Func1(int, char const*)>
491 * Fortran: Support structures with fields of dynamic types and
492 arrays of dynamic types.
494 * The symbol dumping maintenance commands have new syntax.
495 maint print symbols [-pc address] [--] [filename]
496 maint print symbols [-objfile objfile] [-source source] [--] [filename]
497 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
498 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
499 maint print msymbols [-objfile objfile] [--] [filename]
501 * GDB now supports multibit bitfields and enums in target register
504 * New Python-based convenience function $_as_string(val), which returns
505 the textual representation of a value. This function is especially
506 useful to obtain the text label of an enum value.
508 * Intel MPX bound violation handling.
510 Segmentation faults caused by a Intel MPX boundary violation
511 now display the kind of violation (upper or lower), the memory
512 address accessed and the memory bounds, along with the usual
513 signal received and code location.
517 Program received signal SIGSEGV, Segmentation fault
518 Upper bound violation while accessing address 0x7fffffffc3b3
519 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
520 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
522 * Rust language support.
523 GDB now supports debugging programs written in the Rust programming
524 language. See https://www.rust-lang.org/ for more information about
527 * Support for running interpreters on specified input/output devices
529 GDB now supports a new mechanism that allows frontends to provide
530 fully featured GDB console views, as a better alternative to
531 building such views on top of the "-interpreter-exec console"
532 command. See the new "new-ui" command below. With that command,
533 frontends can now start GDB in the traditional command-line mode
534 running in an embedded terminal emulator widget, and create a
535 separate MI interpreter running on a specified i/o device. In this
536 way, GDB handles line editing, history, tab completion, etc. in the
537 console all by itself, and the GUI uses the separate MI interpreter
538 for its own control and synchronization, invisible to the command
541 * The "catch syscall" command catches groups of related syscalls.
543 The "catch syscall" command now supports catching a group of related
544 syscalls using the 'group:' or 'g:' prefix.
549 skip -gfile file-glob-pattern
550 skip -function function
551 skip -rfunction regular-expression
552 A generalized form of the skip command, with new support for
553 glob-style file names and regular expressions for function names.
554 Additionally, a file spec and a function spec may now be combined.
556 maint info line-table REGEXP
557 Display the contents of GDB's internal line table data struture.
560 Run any GDB unit tests that were compiled in.
563 Start a new user interface instance running INTERP as interpreter,
564 using the TTY file for input/output.
568 ** gdb.Breakpoint objects have a new attribute "pending", which
569 indicates whether the breakpoint is pending.
570 ** Three new breakpoint-related events have been added:
571 gdb.breakpoint_created, gdb.breakpoint_modified, and
572 gdb.breakpoint_deleted.
575 Signal ("set") the given MS-Windows event object. This is used in
576 conjunction with the Windows JIT debugging (AeDebug) support, where
577 the OS suspends a crashing process until a debugger can attach to
578 it. Resuming the crashing process, in order to debug it, is done by
581 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
582 was added in GDBserver, including JIT compiling fast tracepoint's
583 conditional expression bytecode into native code.
585 * Support for various remote target protocols and ROM monitors has
588 target m32rsdi Remote M32R debugging over SDI
589 target mips MIPS remote debugging protocol
590 target pmon PMON ROM monitor
591 target ddb NEC's DDB variant of PMON for Vr4300
592 target rockhopper NEC RockHopper variant of PMON
593 target lsi LSI variant of PMO
595 * Support for tracepoints and fast tracepoints on powerpc-linux,
596 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
597 including JIT compiling fast tracepoint's conditional expression
598 bytecode into native code.
600 * MI async record =record-started now includes the method and format used for
601 recording. For example:
603 =record-started,thread-group="i1",method="btrace",format="bts"
605 * MI async record =thread-selected now includes the frame field. For example:
607 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
611 Andes NDS32 nds32*-*-elf
613 *** Changes in GDB 7.11
615 * GDB now supports debugging kernel-based threads on FreeBSD.
617 * Per-inferior thread numbers
619 Thread numbers are now per inferior instead of global. If you're
620 debugging multiple inferiors, GDB displays thread IDs using a
621 qualified INF_NUM.THR_NUM form. For example:
625 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
626 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
627 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
628 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
630 As consequence, thread numbers as visible in the $_thread
631 convenience variable and in Python's InferiorThread.num attribute
632 are no longer unique between inferiors.
634 GDB now maintains a second thread ID per thread, referred to as the
635 global thread ID, which is the new equivalent of thread numbers in
636 previous releases. See also $_gthread below.
638 For backwards compatibility, MI's thread IDs always refer to global
641 * Commands that accept thread IDs now accept the qualified
642 INF_NUM.THR_NUM form as well. For example:
645 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
648 * In commands that accept a list of thread IDs, you can now refer to
649 all threads of an inferior using a star wildcard. GDB accepts
650 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
651 refer to all threads of the current inferior. For example, "info
654 * You can use "info threads -gid" to display the global thread ID of
657 * The new convenience variable $_gthread holds the global number of
660 * The new convenience variable $_inferior holds the number of the
663 * GDB now displays the ID and name of the thread that hit a breakpoint
664 or received a signal, if your program is multi-threaded. For
667 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
668 Thread 1 "main" received signal SIGINT, Interrupt.
670 * Record btrace now supports non-stop mode.
672 * Support for tracepoints on aarch64-linux was added in GDBserver.
674 * The 'record instruction-history' command now indicates speculative execution
675 when using the Intel Processor Trace recording format.
677 * GDB now allows users to specify explicit locations, bypassing
678 the linespec parser. This feature is also available to GDB/MI
681 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
682 GDB now is able to debug both AArch64 applications and ARM applications
685 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
686 including JIT compiling fast tracepoint's conditional expression bytecode
689 * GDB now supports displaced stepping on AArch64 GNU/Linux.
691 * "info threads", "info inferiors", "info display", "info checkpoints"
692 and "maint info program-spaces" now list the corresponding items in
693 ascending ID order, for consistency with all other "info" commands.
695 * In Ada, the overloads selection menu has been enhanced to display the
696 parameter types and the return types for the matching overloaded subprograms.
700 maint set target-non-stop (on|off|auto)
701 maint show target-non-stop
702 Control whether GDB targets always operate in non-stop mode even if
703 "set non-stop" is "off". The default is "auto", meaning non-stop
704 mode is enabled if supported by the target.
706 maint set bfd-sharing
707 maint show bfd-sharing
708 Control the reuse of bfd objects.
712 Control display of debugging info regarding bfd caching.
716 Control display of debugging info regarding FreeBSD threads.
718 set remote multiprocess-extensions-packet
719 show remote multiprocess-extensions-packet
720 Set/show the use of the remote protocol multiprocess extensions.
722 set remote thread-events
723 show remote thread-events
724 Set/show the use of thread create/exit events.
726 set ada print-signatures on|off
727 show ada print-signatures"
728 Control whether parameter types and return types are displayed in overloads
729 selection menus. It is activaled (@code{on}) by default.
733 Controls the maximum size of memory, in bytes, that GDB will
734 allocate for value contents. Prevents incorrect programs from
735 causing GDB to allocate overly large buffers. Default is 64k.
737 * The "disassemble" command accepts a new modifier: /s.
738 It prints mixed source+disassembly like /m with two differences:
739 - disassembled instructions are now printed in program order, and
740 - and source for all relevant files is now printed.
741 The "/m" option is now considered deprecated: its "source-centric"
742 output hasn't proved useful in practice.
744 * The "record instruction-history" command accepts a new modifier: /s.
745 It behaves exactly like /m and prints mixed source+disassembly.
747 * The "set scheduler-locking" command supports a new mode "replay".
748 It behaves like "off" in record mode and like "on" in replay mode.
750 * Support for various ROM monitors has been removed:
752 target dbug dBUG ROM monitor for Motorola ColdFire
753 target picobug Motorola picobug monitor
754 target dink32 DINK32 ROM monitor for PowerPC
755 target m32r Renesas M32R/D ROM monitor
756 target mon2000 mon2000 ROM monitor
757 target ppcbug PPCBUG ROM monitor for PowerPC
759 * Support for reading/writing memory and extracting values on architectures
760 whose memory is addressable in units of any integral multiple of 8 bits.
763 Allows to break when an Ada exception is handled.
768 Indicates that an exec system call was executed.
770 exec-events feature in qSupported
771 The qSupported packet allows GDB to request support for exec
772 events using the new 'gdbfeature' exec-event, and the qSupported
773 response can contain the corresponding 'stubfeature'. Set and
774 show commands can be used to display whether these features are enabled.
777 Equivalent to interrupting with the ^C character, but works in
780 thread created stop reason (T05 create:...)
781 Indicates that the thread was just created and is stopped at entry.
783 thread exit stop reply (w exitcode;tid)
784 Indicates that the thread has terminated.
787 Enables/disables thread create and exit event reporting. For
788 example, this is used in non-stop mode when GDB stops a set of
789 threads and synchronously waits for the their corresponding stop
790 replies. Without exit events, if one of the threads exits, GDB
791 would hang forever not knowing that it should no longer expect a
792 stop for that same thread.
795 Indicates that there are no resumed threads left in the target (all
796 threads are stopped). The remote stub reports support for this stop
797 reply to GDB's qSupported query.
800 Enables/disables catching syscalls from the inferior process.
801 The remote stub reports support for this packet to GDB's qSupported query.
803 syscall_entry stop reason
804 Indicates that a syscall was just called.
806 syscall_return stop reason
807 Indicates that a syscall just returned.
809 * Extended-remote exec events
811 ** GDB now has support for exec events on extended-remote Linux targets.
812 For such targets with Linux kernels 2.5.46 and later, this enables
813 follow-exec-mode and exec catchpoints.
815 set remote exec-event-feature-packet
816 show remote exec-event-feature-packet
817 Set/show the use of the remote exec event feature.
819 * Thread names in remote protocol
821 The reply to qXfer:threads:read may now include a name attribute for each
824 * Target remote mode fork and exec events
826 ** GDB now has support for fork and exec events on target remote mode
827 Linux targets. For such targets with Linux kernels 2.5.46 and later,
828 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
829 fork and exec catchpoints.
831 * Remote syscall events
833 ** GDB now has support for catch syscall on remote Linux targets,
834 currently enabled on x86/x86_64 architectures.
836 set remote catch-syscall-packet
837 show remote catch-syscall-packet
838 Set/show the use of the remote catch syscall feature.
842 ** The -var-set-format command now accepts the zero-hexadecimal
843 format. It outputs data in hexadecimal format with zero-padding on the
848 ** gdb.InferiorThread objects have a new attribute "global_num",
849 which refers to the thread's global thread ID. The existing
850 "num" attribute now refers to the thread's per-inferior number.
851 See "Per-inferior thread numbers" above.
852 ** gdb.InferiorThread objects have a new attribute "inferior", which
853 is the Inferior object the thread belongs to.
855 *** Changes in GDB 7.10
857 * Support for process record-replay and reverse debugging on aarch64*-linux*
858 targets has been added. GDB now supports recording of A64 instruction set
859 including advance SIMD instructions.
861 * Support for Sun's version of the "stabs" debug file format has been removed.
863 * GDB now honors the content of the file /proc/PID/coredump_filter
864 (PID is the process ID) on GNU/Linux systems. This file can be used
865 to specify the types of memory mappings that will be included in a
866 corefile. For more information, please refer to the manual page of
867 "core(5)". GDB also has a new command: "set use-coredump-filter
868 on|off". It allows to set whether GDB will read the content of the
869 /proc/PID/coredump_filter file when generating a corefile.
871 * The "info os" command on GNU/Linux can now display information on
873 "info os cpus" Listing of all cpus/cores on the system
875 * GDB has two new commands: "set serial parity odd|even|none" and
876 "show serial parity". These allows to set or show parity for the
879 * The "info source" command now displays the producer string if it was
880 present in the debug info. This typically includes the compiler version
881 and may include things like its command line arguments.
883 * The "info dll", an alias of the "info sharedlibrary" command,
884 is now available on all platforms.
886 * Directory names supplied to the "set sysroot" commands may be
887 prefixed with "target:" to tell GDB to access shared libraries from
888 the target system, be it local or remote. This replaces the prefix
889 "remote:". The default sysroot has been changed from "" to
890 "target:". "remote:" is automatically converted to "target:" for
891 backward compatibility.
893 * The system root specified by "set sysroot" will be prepended to the
894 filename of the main executable (if reported to GDB as absolute by
895 the operating system) when starting processes remotely, and when
896 attaching to already-running local or remote processes.
898 * GDB now supports automatic location and retrieval of executable
899 files from remote targets. Remote debugging can now be initiated
900 using only a "target remote" or "target extended-remote" command
901 (no "set sysroot" or "file" commands are required). See "New remote
904 * The "dump" command now supports verilog hex format.
906 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
908 * On GNU/Linux, GDB and gdbserver are now able to access executable
909 and shared library files without a "set sysroot" command when
910 attaching to processes running in different mount namespaces from
911 the debugger. This makes it possible to attach to processes in
912 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
913 See "New remote packets" below.
915 * The "tui reg" command now provides completion for all of the
916 available register groups, including target specific groups.
918 * The HISTSIZE environment variable is no longer read when determining
919 the size of GDB's command history. GDB now instead reads the dedicated
920 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
921 disables truncation of command history. Non-numeric values of GDBHISTSIZE
926 ** Memory ports can now be unbuffered.
930 ** gdb.Objfile objects have a new attribute "username",
931 which is the name of the objfile as specified by the user,
932 without, for example, resolving symlinks.
933 ** You can now write frame unwinders in Python.
934 ** gdb.Type objects have a new method "optimized_out",
935 returning optimized out gdb.Value instance of this type.
936 ** gdb.Value objects have new methods "reference_value" and
937 "const_value" which return a reference to the value and a
938 "const" version of the value respectively.
942 maint print symbol-cache
943 Print the contents of the symbol cache.
945 maint print symbol-cache-statistics
946 Print statistics of symbol cache usage.
948 maint flush-symbol-cache
949 Flush the contents of the symbol cache.
953 Start branch trace recording using Branch Trace Store (BTS) format.
956 Evaluate expression by using the compiler and print result.
960 Explicit commands for enabling and disabling tui mode.
963 set mpx bound on i386 and amd64
964 Support for bound table investigation on Intel MPX enabled applications.
968 Start branch trace recording using Intel Processor Trace format.
971 Print information about branch tracing internals.
973 maint btrace packet-history
974 Print the raw branch tracing data.
976 maint btrace clear-packet-history
977 Discard the stored raw branch tracing data.
980 Discard all branch tracing data. It will be fetched and processed
981 anew by the next "record" command.
986 Renamed from "set debug dwarf2-die".
988 Renamed from "show debug dwarf2-die".
991 Renamed from "set debug dwarf2-read".
992 show debug dwarf-read
993 Renamed from "show debug dwarf2-read".
995 maint set dwarf always-disassemble
996 Renamed from "maint set dwarf2 always-disassemble".
997 maint show dwarf always-disassemble
998 Renamed from "maint show dwarf2 always-disassemble".
1000 maint set dwarf max-cache-age
1001 Renamed from "maint set dwarf2 max-cache-age".
1002 maint show dwarf max-cache-age
1003 Renamed from "maint show dwarf2 max-cache-age".
1005 set debug dwarf-line
1006 show debug dwarf-line
1007 Control display of debugging info regarding DWARF line processing.
1010 show max-completions
1011 Set the maximum number of candidates to be considered during
1012 completion. The default value is 200. This limit allows GDB
1013 to avoid generating large completion lists, the computation of
1014 which can cause the debugger to become temporarily unresponsive.
1016 set history remove-duplicates
1017 show history remove-duplicates
1018 Control the removal of duplicate history entries.
1020 maint set symbol-cache-size
1021 maint show symbol-cache-size
1022 Control the size of the symbol cache.
1024 set|show record btrace bts buffer-size
1025 Set and show the size of the ring buffer used for branch tracing in
1027 The obtained size may differ from the requested size. Use "info
1028 record" to see the obtained buffer size.
1030 set debug linux-namespaces
1031 show debug linux-namespaces
1032 Control display of debugging info regarding Linux namespaces.
1034 set|show record btrace pt buffer-size
1035 Set and show the size of the ring buffer used for branch tracing in
1036 Intel Processor Trace format.
1037 The obtained size may differ from the requested size. Use "info
1038 record" to see the obtained buffer size.
1040 maint set|show btrace pt skip-pad
1041 Set and show whether PAD packets are skipped when computing the
1044 * The command 'thread apply all' can now support new option '-ascending'
1045 to call its specified command for all threads in ascending order.
1047 * Python/Guile scripting
1049 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1050 special section named `.debug_gdb_scripts'.
1052 * New remote packets
1054 qXfer:btrace-conf:read
1055 Return the branch trace configuration for the current thread.
1057 Qbtrace-conf:bts:size
1058 Set the requested ring buffer size for branch tracing in BTS format.
1061 Enable Intel Procesor Trace-based branch tracing for the current
1062 process. The remote stub reports support for this packet to GDB's
1065 Qbtrace-conf:pt:size
1066 Set the requested ring buffer size for branch tracing in Intel Processor
1070 Indicates a memory breakpoint instruction was executed, irrespective
1071 of whether it was GDB that planted the breakpoint or the breakpoint
1072 is hardcoded in the program. This is required for correct non-stop
1076 Indicates the target stopped for a hardware breakpoint. This is
1077 required for correct non-stop mode operation.
1080 Return information about files on the remote system.
1082 qXfer:exec-file:read
1083 Return the full absolute name of the file that was executed to
1084 create a process running on the remote system.
1087 Select the filesystem on which vFile: operations with filename
1088 arguments will operate. This is required for GDB to be able to
1089 access files on remote targets where the remote stub does not
1090 share a common filesystem with the inferior(s).
1093 Indicates that a fork system call was executed.
1096 Indicates that a vfork system call was executed.
1098 vforkdone stop reason
1099 Indicates that a vfork child of the specified process has executed
1100 an exec or exit, allowing the vfork parent to resume execution.
1102 fork-events and vfork-events features in qSupported
1103 The qSupported packet allows GDB to request support for fork and
1104 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1105 and the qSupported response can contain the corresponding
1106 'stubfeatures'. Set and show commands can be used to display
1107 whether these features are enabled.
1109 * Extended-remote fork events
1111 ** GDB now has support for fork events on extended-remote Linux
1112 targets. For targets with Linux kernels 2.5.60 and later, this
1113 enables follow-fork-mode and detach-on-fork for both fork and
1114 vfork, as well as fork and vfork catchpoints.
1116 * The info record command now shows the recording format and the
1117 branch tracing configuration for the current thread when using
1118 the btrace record target.
1119 For the BTS format, it shows the ring buffer size.
1121 * GDB now has support for DTrace USDT (Userland Static Defined
1122 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1124 * GDB now supports access to vector registers on S/390 GNU/Linux
1127 * Removed command line options
1129 -xdb HP-UX XDB compatibility mode.
1131 * Removed targets and native configurations
1133 HP/PA running HP-UX hppa*-*-hpux*
1134 Itanium running HP-UX ia64-*-hpux*
1136 * New configure options
1139 This configure option allows the user to build GDB with support for
1140 Intel Processor Trace (default: auto). This requires libipt.
1142 --with-libipt-prefix=PATH
1143 Specify the path to the version of libipt that GDB should use.
1144 $PATH/include should contain the intel-pt.h header and
1145 $PATH/lib should contain the libipt.so library.
1147 *** Changes in GDB 7.9.1
1151 ** Xmethods can now specify a result type.
1153 *** Changes in GDB 7.9
1155 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1159 ** You can now access frame registers from Python scripts.
1160 ** New attribute 'producer' for gdb.Symtab objects.
1161 ** gdb.Objfile objects have a new attribute "progspace",
1162 which is the gdb.Progspace object of the containing program space.
1163 ** gdb.Objfile objects have a new attribute "owner".
1164 ** gdb.Objfile objects have a new attribute "build_id",
1165 which is the build ID generated when the file was built.
1166 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1167 ** A new event "gdb.clear_objfiles" has been added, triggered when
1168 selecting a new file to debug.
1169 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1170 ** New function gdb.lookup_objfile.
1172 New events which are triggered when GDB modifies the state of the
1175 ** gdb.events.inferior_call_pre: Function call is about to be made.
1176 ** gdb.events.inferior_call_post: Function call has just been made.
1177 ** gdb.events.memory_changed: A memory location has been altered.
1178 ** gdb.events.register_changed: A register has been altered.
1180 * New Python-based convenience functions:
1182 ** $_caller_is(name [, number_of_frames])
1183 ** $_caller_matches(regexp [, number_of_frames])
1184 ** $_any_caller_is(name [, number_of_frames])
1185 ** $_any_caller_matches(regexp [, number_of_frames])
1187 * GDB now supports the compilation and injection of source code into
1188 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1189 to compile the source code to object code, and if successful, inject
1190 and execute that code within the current context of the inferior.
1191 Currently the C language is supported. The commands used to
1192 interface with this new feature are:
1194 compile code [-raw|-r] [--] [source code]
1195 compile file [-raw|-r] filename
1199 demangle [-l language] [--] name
1200 Demangle "name" in the specified language, or the current language
1201 if elided. This command is renamed from the "maint demangle" command.
1202 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1203 as "maint demangler-warning".
1205 queue-signal signal-name-or-number
1206 Queue a signal to be delivered to the thread when it is resumed.
1208 add-auto-load-scripts-directory directory
1209 Add entries to the list of directories from which to load auto-loaded
1212 maint print user-registers
1213 List all currently available "user" registers.
1215 compile code [-r|-raw] [--] [source code]
1216 Compile, inject, and execute in the inferior the executable object
1217 code produced by compiling the provided source code.
1219 compile file [-r|-raw] filename
1220 Compile and inject into the inferior the executable object code
1221 produced by compiling the source code stored in the filename
1224 * On resume, GDB now always passes the signal the program had stopped
1225 for to the thread the signal was sent to, even if the user changed
1226 threads before resuming. Previously GDB would often (but not
1227 always) deliver the signal to the thread that happens to be current
1230 * Conversely, the "signal" command now consistently delivers the
1231 requested signal to the current thread. GDB now asks for
1232 confirmation if the program had stopped for a signal and the user
1233 switched threads meanwhile.
1235 * "breakpoint always-inserted" modes "off" and "auto" merged.
1237 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1238 won't remove breakpoints from the target until all threads stop,
1239 even in non-stop mode. The "auto" mode has been removed, and "off"
1240 is now the default mode.
1244 set debug symbol-lookup
1245 show debug symbol-lookup
1246 Control display of debugging info regarding symbol lookup.
1250 ** The -list-thread-groups command outputs an exit-code field for
1251 inferiors that have exited.
1255 MIPS SDE mips*-sde*-elf*
1259 Support for these obsolete configurations has been removed.
1261 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1262 SGI Irix-5.x mips-*-irix5*
1263 SGI Irix-6.x mips-*-irix6*
1264 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1265 VAX running Ultrix vax-*-ultrix*
1267 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1268 and "assf"), have been removed. Use the "sharedlibrary" command, or
1269 its alias "share", instead.
1271 *** Changes in GDB 7.8
1273 * New command line options
1276 This is an alias for the --data-directory option.
1278 * GDB supports printing and modifying of variable length automatic arrays
1279 as specified in ISO C99.
1281 * The ARM simulator now supports instruction level tracing
1282 with or without disassembly.
1286 GDB now has support for scripting using Guile. Whether this is
1287 available is determined at configure time.
1288 Guile version 2.0 or greater is required.
1289 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1291 * New commands (for set/show, see "New options" below)
1295 Invoke CODE by passing it to the Guile interpreter.
1299 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1301 info auto-load guile-scripts [regexp]
1302 Print the list of automatically loaded Guile scripts.
1304 * The source command is now capable of sourcing Guile scripts.
1305 This feature is dependent on the debugger being built with Guile support.
1309 set print symbol-loading (off|brief|full)
1310 show print symbol-loading
1311 Control whether to print informational messages when loading symbol
1312 information for a file. The default is "full", but when debugging
1313 programs with large numbers of shared libraries the amount of output
1314 becomes less useful.
1316 set guile print-stack (none|message|full)
1317 show guile print-stack
1318 Show a stack trace when an error is encountered in a Guile script.
1320 set auto-load guile-scripts (on|off)
1321 show auto-load guile-scripts
1322 Control auto-loading of Guile script files.
1324 maint ada set ignore-descriptive-types (on|off)
1325 maint ada show ignore-descriptive-types
1326 Control whether the debugger should ignore descriptive types in Ada
1327 programs. The default is not to ignore the descriptive types. See
1328 the user manual for more details on descriptive types and the intended
1329 usage of this option.
1331 set auto-connect-native-target
1333 Control whether GDB is allowed to automatically connect to the
1334 native target for the run, attach, etc. commands when not connected
1335 to any target yet. See also "target native" below.
1337 set record btrace replay-memory-access (read-only|read-write)
1338 show record btrace replay-memory-access
1339 Control what memory accesses are allowed during replay.
1341 maint set target-async (on|off)
1342 maint show target-async
1343 This controls whether GDB targets operate in synchronous or
1344 asynchronous mode. Normally the default is asynchronous, if it is
1345 available; but this can be changed to more easily debug problems
1346 occurring only in synchronous mode.
1348 set mi-async (on|off)
1350 Control whether MI asynchronous mode is preferred. This supersedes
1351 "set target-async" of previous GDB versions.
1353 * "set target-async" is deprecated as a CLI option and is now an alias
1354 for "set mi-async" (only puts MI into async mode).
1356 * Background execution commands (e.g., "c&", "s&", etc.) are now
1357 possible ``out of the box'' if the target supports them. Previously
1358 the user would need to explicitly enable the possibility with the
1359 "set target-async on" command.
1361 * New features in the GDB remote stub, GDBserver
1363 ** New option --debug-format=option1[,option2,...] allows one to add
1364 additional text to each output. At present only timestamps
1365 are supported: --debug-format=timestamps.
1366 Timestamps can also be turned on with the
1367 "monitor set debug-format timestamps" command from GDB.
1369 * The 'record instruction-history' command now starts counting instructions
1370 at one. This also affects the instruction ranges reported by the
1371 'record function-call-history' command when given the /i modifier.
1373 * The command 'record function-call-history' supports a new modifier '/c' to
1374 indent the function names based on their call stack depth.
1375 The fields for the '/i' and '/l' modifier have been reordered.
1376 The source line range is now prefixed with 'at'.
1377 The instruction range is now prefixed with 'inst'.
1378 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1379 "record instruction-history" and "list" commands.
1381 * The ranges given as arguments to the 'record function-call-history' and
1382 'record instruction-history' commands are now inclusive.
1384 * The btrace record target now supports the 'record goto' command.
1385 For locations inside the execution trace, the back trace is computed
1386 based on the information stored in the execution trace.
1388 * The btrace record target supports limited reverse execution and replay.
1389 The target does not record data and therefore does not allow reading
1390 memory or registers.
1392 * The "catch syscall" command now works on s390*-linux* targets.
1394 * The "compare-sections" command is no longer specific to target
1395 remote. It now works with all targets.
1397 * All native targets are now consistently called "native".
1398 Consequently, the "target child", "target GNU", "target djgpp",
1399 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1400 commands have been replaced with "target native". The QNX/NTO port
1401 leaves the "procfs" target in place and adds a "native" target for
1402 consistency with other ports. The impact on users should be minimal
1403 as these commands previously either throwed an error, or were
1404 no-ops. The target's name is visible in the output of the following
1405 commands: "help target", "info target", "info files", "maint print
1408 * The "target native" command now connects to the native target. This
1409 can be used to launch native programs even when "set
1410 auto-connect-native-target" is set to off.
1412 * GDB now supports access to Intel MPX registers on GNU/Linux.
1414 * Support for Intel AVX-512 registers on GNU/Linux.
1415 Support displaying and modifying Intel AVX-512 registers
1416 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1418 * New remote packets
1420 qXfer:btrace:read's annex
1421 The qXfer:btrace:read packet supports a new annex 'delta' to read
1422 branch trace incrementally.
1426 ** Valid Python operations on gdb.Value objects representing
1427 structs/classes invoke the corresponding overloaded operators if
1429 ** New `Xmethods' feature in the Python API. Xmethods are
1430 additional methods or replacements for existing methods of a C++
1431 class. This feature is useful for those cases where a method
1432 defined in C++ source code could be inlined or optimized out by
1433 the compiler, making it unavailable to GDB.
1436 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1438 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1439 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1440 its alias "share", instead.
1442 * The commands "set remotebaud" and "show remotebaud" are no longer
1443 supported. Use "set serial baud" and "show serial baud" (respectively)
1448 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1449 target-async". The latter is left as a deprecated alias of the
1450 former for backward compatibility. If the target supports it,
1451 CLI background execution commands are now always possible by
1452 default, independently of whether the frontend stated a
1453 preference for asynchronous execution with "-gdb-set mi-async".
1454 Previously "-gdb-set target-async off" affected both MI execution
1455 commands and CLI execution commands.
1457 *** Changes in GDB 7.7
1459 * Improved support for process record-replay and reverse debugging on
1460 arm*-linux* targets. Support for thumb32 and syscall instruction
1461 recording has been added.
1463 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1465 * GDB now supports Fission DWP file format version 2.
1466 http://gcc.gnu.org/wiki/DebugFission
1468 * New convenience function "$_isvoid", to check whether an expression
1469 is void. A void expression is an expression where the type of the
1470 result is "void". For example, some convenience variables may be
1471 "void" when evaluated (e.g., "$_exitcode" before the execution of
1472 the program being debugged; or an undefined convenience variable).
1473 Another example, when calling a function whose return type is
1476 * The "maintenance print objfiles" command now takes an optional regexp.
1478 * The "catch syscall" command now works on arm*-linux* targets.
1480 * GDB now consistently shows "<not saved>" when printing values of
1481 registers the debug info indicates have not been saved in the frame
1482 and there's nowhere to retrieve them from
1483 (callee-saved/call-clobbered registers):
1488 (gdb) info registers rax
1491 Before, the former would print "<optimized out>", and the latter
1492 "*value not available*".
1494 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1499 ** Frame filters and frame decorators have been added.
1500 ** Temporary breakpoints are now supported.
1501 ** Line tables representation has been added.
1502 ** New attribute 'parent_type' for gdb.Field objects.
1503 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1504 ** New attribute 'name' for gdb.Type objects.
1508 Nios II ELF nios2*-*-elf
1509 Nios II GNU/Linux nios2*-*-linux
1510 Texas Instruments MSP430 msp430*-*-elf
1512 * Removed native configurations
1514 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1515 been removed. ELF variants of these configurations are kept supported.
1517 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1518 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1519 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1520 i[34567]86-*-openbsd3.[0-3]
1521 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1522 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1523 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1527 Like "catch throw", but catches a re-thrown exception.
1528 maint check-psymtabs
1529 Renamed from old "maint check-symtabs".
1531 Perform consistency checks on symtabs.
1532 maint expand-symtabs
1533 Expand symtabs matching an optional regexp.
1536 Display the details of GDB configure-time options.
1538 maint set|show per-command
1539 maint set|show per-command space
1540 maint set|show per-command time
1541 maint set|show per-command symtab
1542 Enable display of per-command gdb resource usage.
1544 remove-symbol-file FILENAME
1545 remove-symbol-file -a ADDRESS
1546 Remove a symbol file added via add-symbol-file. The file to remove
1547 can be identified by its filename or by an address that lies within
1548 the boundaries of this symbol file in memory.
1551 info exceptions REGEXP
1552 Display the list of Ada exceptions defined in the program being
1553 debugged. If provided, only the exceptions whose names match REGEXP
1558 set debug symfile off|on
1560 Control display of debugging info regarding reading symbol files and
1561 symbol tables within those files
1563 set print raw frame-arguments
1564 show print raw frame-arguments
1565 Set/show whether to print frame arguments in raw mode,
1566 disregarding any defined pretty-printers.
1568 set remote trace-status-packet
1569 show remote trace-status-packet
1570 Set/show the use of remote protocol qTStatus packet.
1574 Control display of debugging messages related to Nios II targets.
1578 Control whether target-assisted range stepping is enabled.
1580 set startup-with-shell
1581 show startup-with-shell
1582 Specifies whether Unix child processes are started via a shell or
1587 Use the target memory cache for accesses to the code segment. This
1588 improves performance of remote debugging (particularly disassembly).
1590 * You can now use a literal value 'unlimited' for options that
1591 interpret 0 or -1 as meaning "unlimited". E.g., "set
1592 trace-buffer-size unlimited" is now an alias for "set
1593 trace-buffer-size -1" and "set height unlimited" is now an alias for
1596 * The "set debug symtab-create" debugging option of GDB has been changed to
1597 accept a verbosity level. 0 means "off", 1 provides basic debugging
1598 output, and values of 2 or greater provides more verbose output.
1600 * New command-line options
1602 Display the details of GDB configure-time options.
1604 * The command 'tsave' can now support new option '-ctf' to save trace
1605 buffer in Common Trace Format.
1607 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1610 * GDB now implements the the C++ 'typeid' operator.
1612 * The new convenience variable $_exception holds the exception being
1613 thrown or caught at an exception-related catchpoint.
1615 * The exception-related catchpoints, like "catch throw", now accept a
1616 regular expression which can be used to filter exceptions by type.
1618 * The new convenience variable $_exitsignal is automatically set to
1619 the terminating signal number when the program being debugged dies
1620 due to an uncaught signal.
1624 ** All MI commands now accept an optional "--language" option.
1625 Support for this feature can be verified by using the "-list-features"
1626 command, which should contain "language-option".
1628 ** The new command -info-gdb-mi-command allows the user to determine
1629 whether a GDB/MI command is supported or not.
1631 ** The "^error" result record returned when trying to execute an undefined
1632 GDB/MI command now provides a variable named "code" whose content is the
1633 "undefined-command" error code. Support for this feature can be verified
1634 by using the "-list-features" command, which should contain
1635 "undefined-command-error-code".
1637 ** The -trace-save MI command can optionally save trace buffer in Common
1640 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1642 ** The command -data-list-register-values now accepts an optional
1643 "--skip-unavailable" option. When used, only the available registers
1646 ** The new command -trace-frame-collected dumps collected variables,
1647 computed expressions, tvars, memory and registers in a traceframe.
1649 ** The commands -stack-list-locals, -stack-list-arguments and
1650 -stack-list-variables now accept an option "--skip-unavailable".
1651 When used, only the available locals or arguments are displayed.
1653 ** The -exec-run command now accepts an optional "--start" option.
1654 When used, the command follows the same semantics as the "start"
1655 command, stopping the program's execution at the start of its
1656 main subprogram. Support for this feature can be verified using
1657 the "-list-features" command, which should contain
1658 "exec-run-start-option".
1660 ** The new commands -catch-assert and -catch-exceptions insert
1661 catchpoints stopping the program when Ada exceptions are raised.
1663 ** The new command -info-ada-exceptions provides the equivalent of
1664 the new "info exceptions" command.
1666 * New system-wide configuration scripts
1667 A GDB installation now provides scripts suitable for use as system-wide
1668 configuration scripts for the following systems:
1672 * GDB now supports target-assigned range stepping with remote targets.
1673 This improves the performance of stepping source lines by reducing
1674 the number of control packets from/to GDB. See "New remote packets"
1677 * GDB now understands the element 'tvar' in the XML traceframe info.
1678 It has the id of the collected trace state variables.
1680 * On S/390 targets that provide the transactional-execution feature,
1681 the program interruption transaction diagnostic block (TDB) is now
1682 represented as a number of additional "registers" in GDB.
1684 * New remote packets
1688 The vCont packet supports a new 'r' action, that tells the remote
1689 stub to step through an address range itself, without GDB
1690 involvemement at each single-step.
1692 qXfer:libraries-svr4:read's annex
1693 The previously unused annex of the qXfer:libraries-svr4:read packet
1694 is now used to support passing an argument list. The remote stub
1695 reports support for this argument list to GDB's qSupported query.
1696 The defined arguments are "start" and "prev", used to reduce work
1697 necessary for library list updating, resulting in significant
1700 * New features in the GDB remote stub, GDBserver
1702 ** GDBserver now supports target-assisted range stepping. Currently
1703 enabled on x86/x86_64 GNU/Linux targets.
1705 ** GDBserver now adds element 'tvar' in the XML in the reply to
1706 'qXfer:traceframe-info:read'. It has the id of the collected
1707 trace state variables.
1709 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1712 * New 'z' formatter for printing and examining memory, this displays the
1713 value as hexadecimal zero padded on the left to the size of the type.
1715 * GDB can now use Windows x64 unwinding data.
1717 * The "set remotebaud" command has been replaced by "set serial baud".
1718 Similarly, "show remotebaud" has been replaced by "show serial baud".
1719 The "set remotebaud" and "show remotebaud" commands are still available
1720 to provide backward compatibility with older versions of GDB.
1722 *** Changes in GDB 7.6
1724 * Target record has been renamed to record-full.
1725 Record/replay is now enabled with the "record full" command.
1726 This also affects settings that are associated with full record/replay
1727 that have been moved from "set/show record" to "set/show record full":
1729 set|show record full insn-number-max
1730 set|show record full stop-at-limit
1731 set|show record full memory-query
1733 * A new record target "record-btrace" has been added. The new target
1734 uses hardware support to record the control-flow of a process. It
1735 does not support replaying the execution, but it implements the
1736 below new commands for investigating the recorded execution log.
1737 This new recording method can be enabled using:
1741 The "record-btrace" target is only available on Intel Atom processors
1742 and requires a Linux kernel 2.6.32 or later.
1744 * Two new commands have been added for record/replay to give information
1745 about the recorded execution without having to replay the execution.
1746 The commands are only supported by "record btrace".
1748 record instruction-history prints the execution history at
1749 instruction granularity
1751 record function-call-history prints the execution history at
1752 function granularity
1754 * New native configurations
1756 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1757 FreeBSD/powerpc powerpc*-*-freebsd
1758 x86_64/Cygwin x86_64-*-cygwin*
1759 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1763 ARM AArch64 aarch64*-*-elf
1764 ARM AArch64 GNU/Linux aarch64*-*-linux
1765 Lynx 178 PowerPC powerpc-*-lynx*178
1766 x86_64/Cygwin x86_64-*-cygwin*
1767 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1769 * If the configured location of system.gdbinit file (as given by the
1770 --with-system-gdbinit option at configure time) is in the
1771 data-directory (as specified by --with-gdb-datadir at configure
1772 time) or in one of its subdirectories, then GDB will look for the
1773 system-wide init file in the directory specified by the
1774 --data-directory command-line option.
1776 * New command line options:
1778 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1779 other initialization files, unlike -nx which disables all of them.
1781 * Removed command line options
1783 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1786 * The 'ptype' and 'whatis' commands now accept an argument to control
1789 * 'info proc' now works on some core files.
1793 ** Vectors can be created with gdb.Type.vector.
1795 ** Python's atexit.register now works in GDB.
1797 ** Types can be pretty-printed via a Python API.
1799 ** Python 3 is now supported (in addition to Python 2.4 or later)
1801 ** New class gdb.Architecture exposes GDB's internal representation
1802 of architecture in the Python API.
1804 ** New method Frame.architecture returns the gdb.Architecture object
1805 corresponding to the frame's architecture.
1807 * New Python-based convenience functions:
1809 ** $_memeq(buf1, buf2, length)
1810 ** $_streq(str1, str2)
1812 ** $_regex(str, regex)
1814 * The 'cd' command now defaults to using '~' (the home directory) if not
1817 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1818 default for GCC since November 2000.
1820 * The command 'forward-search' can now be abbreviated as 'fo'.
1822 * The command 'info tracepoints' can now display 'installed on target'
1823 or 'not installed on target' for each non-pending location of tracepoint.
1825 * New configure options
1827 --enable-libmcheck/--disable-libmcheck
1828 By default, development versions are built with -lmcheck on hosts
1829 that support it, in order to help track memory corruption issues.
1830 Release versions, on the other hand, are built without -lmcheck
1831 by default. The --enable-libmcheck/--disable-libmcheck configure
1832 options allow the user to override that default.
1833 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1834 This configure option allows the user to build GDB with
1835 libbabeltrace using which GDB can read Common Trace Format data.
1837 * New commands (for set/show, see "New options" below)
1840 Catch signals. This is similar to "handle", but allows commands and
1841 conditions to be attached.
1844 List the BFDs known to GDB.
1846 python-interactive [command]
1848 Start a Python interactive prompt, or evaluate the optional command
1849 and print the result of expressions.
1852 "py" is a new alias for "python".
1854 enable type-printer [name]...
1855 disable type-printer [name]...
1856 Enable or disable type printers.
1860 ** For the Renesas Super-H architecture, the "regs" command has been removed
1861 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1866 set print type methods (on|off)
1867 show print type methods
1868 Control whether method declarations are displayed by "ptype".
1869 The default is to show them.
1871 set print type typedefs (on|off)
1872 show print type typedefs
1873 Control whether typedef definitions are displayed by "ptype".
1874 The default is to show them.
1876 set filename-display basename|relative|absolute
1877 show filename-display
1878 Control the way in which filenames is displayed.
1879 The default is "relative", which preserves previous behavior.
1881 set trace-buffer-size
1882 show trace-buffer-size
1883 Request target to change the size of trace buffer.
1885 set remote trace-buffer-size-packet auto|on|off
1886 show remote trace-buffer-size-packet
1887 Control the use of the remote protocol `QTBuffer:size' packet.
1891 Control display of debugging messages related to ARM AArch64.
1894 set debug coff-pe-read
1895 show debug coff-pe-read
1896 Control display of debugging messages related to reading of COFF/PE
1901 Control display of debugging messages related to Mach-O symbols
1904 set debug notification
1905 show debug notification
1906 Control display of debugging info for async remote notification.
1910 ** Command parameter changes are now notified using new async record
1911 "=cmd-param-changed".
1912 ** Trace frame changes caused by command "tfind" are now notified using
1913 new async record "=traceframe-changed".
1914 ** The creation, deletion and modification of trace state variables
1915 are now notified using new async records "=tsv-created",
1916 "=tsv-deleted" and "=tsv-modified".
1917 ** The start and stop of process record are now notified using new
1918 async record "=record-started" and "=record-stopped".
1919 ** Memory changes are now notified using new async record
1921 ** The data-disassemble command response will include a "fullname" field
1922 containing the absolute file name when source has been requested.
1923 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1924 command, to allow pattern filling of memory areas.
1925 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1926 library load/unload events.
1927 ** The response to breakpoint commands and breakpoint async records
1928 includes an "installed" field containing a boolean state about each
1929 non-pending tracepoint location is whether installed on target or not.
1930 ** Output of the "-trace-status" command includes a "trace-file" field
1931 containing the name of the trace file being examined. This field is
1932 optional, and only present when examining a trace file.
1933 ** The "fullname" field is now always present along with the "file" field,
1934 even if the file cannot be found by GDB.
1936 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1937 You must have the LZMA library available when configuring GDB for this
1938 feature to be enabled. For more information, see:
1939 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1941 * New remote packets
1944 Set the size of trace buffer. The remote stub reports support for this
1945 packet to gdb's qSupported query.
1948 Enable Branch Trace Store (BTS)-based branch tracing for the current
1949 thread. The remote stub reports support for this packet to gdb's
1953 Disable branch tracing for the current thread. The remote stub reports
1954 support for this packet to gdb's qSupported query.
1957 Read the traced branches for the current thread. The remote stub
1958 reports support for this packet to gdb's qSupported query.
1960 *** Changes in GDB 7.5
1962 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1963 for more x32 ABI info.
1965 * GDB now supports access to MIPS DSP registers on Linux targets.
1967 * GDB now supports debugging microMIPS binaries.
1969 * The "info os" command on GNU/Linux can now display information on
1970 several new classes of objects managed by the operating system:
1971 "info os procgroups" lists process groups
1972 "info os files" lists file descriptors
1973 "info os sockets" lists internet-domain sockets
1974 "info os shm" lists shared-memory regions
1975 "info os semaphores" lists semaphores
1976 "info os msg" lists message queues
1977 "info os modules" lists loaded kernel modules
1979 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1980 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1981 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1982 options and inspect the probe arguments using the new $_probe_arg family
1983 of convenience variables. You can obtain more information about SystemTap
1984 in <http://sourceware.org/systemtap/>.
1986 * GDB now supports reversible debugging on ARM, it allows you to
1987 debug basic ARM and THUMB instructions, and provides
1988 record/replay support.
1990 * The option "symbol-reloading" has been deleted as it is no longer used.
1994 ** GDB commands implemented in Python can now be put in command class
1997 ** The "maint set python print-stack on|off" is now deleted.
1999 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2000 apply "flag enum"-style pretty-printing to any enum.
2002 ** gdb.lookup_symbol can now work when there is no current frame.
2004 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2005 the source at which the symbol was defined.
2007 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2008 method 'value'. The former indicates whether the symbol needs a
2009 frame in order to compute its value, and the latter computes the
2012 ** A new method 'referenced_value' on gdb.Value objects which can
2013 dereference pointer as well as C++ reference values.
2015 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2016 which return the global and static blocks (as gdb.Block objects),
2017 of the underlying symbol table, respectively.
2019 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2020 object associated with a PC value.
2022 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2023 of the address range occupied by code for the current source line.
2025 * Go language support.
2026 GDB now supports debugging programs written in the Go programming
2029 * GDBserver now supports stdio connections.
2030 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2032 * The binary "gdbtui" can no longer be built or installed.
2033 Use "gdb -tui" instead.
2035 * GDB will now print "flag" enums specially. A flag enum is one where
2036 all the enumerator values have no bits in common when pairwise
2037 "and"ed. When printing a value whose type is a flag enum, GDB will
2038 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2039 (gdb) print (enum E) 3
2042 * The filename part of a linespec will now match trailing components
2043 of a source file name. For example, "break gcc/expr.c:1000" will
2044 now set a breakpoint in build/gcc/expr.c, but not
2045 build/libcpp/expr.c.
2047 * The "info proc" and "generate-core-file" commands will now also
2048 work on remote targets connected to GDBserver on Linux.
2050 * The command "info catch" has been removed. It has been disabled
2051 since December 2007.
2053 * The "catch exception" and "catch assert" commands now accept
2054 a condition at the end of the command, much like the "break"
2055 command does. For instance:
2057 (gdb) catch exception Constraint_Error if Barrier = True
2059 Previously, it was possible to add a condition to such catchpoints,
2060 but it had to be done as a second step, after the catchpoint had been
2061 created, using the "condition" command.
2063 * The "info static-tracepoint-marker" command will now also work on
2064 native Linux targets with in-process agent.
2066 * GDB can now set breakpoints on inlined functions.
2068 * The .gdb_index section has been updated to include symbols for
2069 inlined functions. GDB will ignore older .gdb_index sections by
2070 default, which could cause symbol files to be loaded more slowly
2071 until their .gdb_index sections can be recreated. The new command
2072 "set use-deprecated-index-sections on" will cause GDB to use any older
2073 .gdb_index sections it finds. This will restore performance, but the
2074 ability to set breakpoints on inlined functions will be lost in symbol
2075 files with older .gdb_index sections.
2077 The .gdb_index section has also been updated to record more information
2078 about each symbol. This speeds up the "info variables", "info functions"
2079 and "info types" commands when used with programs having the .gdb_index
2080 section, as well as speeding up debugging with shared libraries using
2081 the .gdb_index section.
2083 * Ada support for GDB/MI Variable Objects has been added.
2085 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2090 ** New command -info-os is the MI equivalent of "info os".
2092 ** Output logs ("set logging" and related) now include MI output.
2096 ** "set use-deprecated-index-sections on|off"
2097 "show use-deprecated-index-sections on|off"
2098 Controls the use of deprecated .gdb_index sections.
2100 ** "catch load" and "catch unload" can be used to stop when a shared
2101 library is loaded or unloaded, respectively.
2103 ** "enable count" can be used to auto-disable a breakpoint after
2106 ** "info vtbl" can be used to show the virtual method tables for
2107 C++ and Java objects.
2109 ** "explore" and its sub commands "explore value" and "explore type"
2110 can be used to recursively explore values and types of
2111 expressions. These commands are available only if GDB is
2112 configured with '--with-python'.
2114 ** "info auto-load" shows status of all kinds of auto-loaded files,
2115 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2116 sequences of commands files, "info auto-load python-scripts"
2117 shows status of auto-loading Python script files,
2118 "info auto-load local-gdbinit" shows status of loading init file
2119 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2120 status of inferior specific thread debugging shared library loading.
2122 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2123 and "show auto-load-scripts" commands have been deprecated, use their
2124 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2125 and "show auto-load python-scripts" counterparts instead.
2127 ** "dprintf location,format,args..." creates a dynamic printf, which
2128 is basically a breakpoint that does a printf and immediately
2129 resumes your program's execution, so it is like a printf that you
2130 can insert dynamically at runtime instead of at compiletime.
2132 ** "set print symbol"
2134 Controls whether GDB attempts to display the symbol, if any,
2135 corresponding to addresses it prints. This defaults to "on", but
2136 you can set it to "off" to restore GDB's previous behavior.
2138 * Deprecated commands
2140 ** For the Renesas Super-H architecture, the "regs" command has been
2141 deprecated, and "info all-registers" should be used instead.
2145 Renesas RL78 rl78-*-elf
2146 HP OpenVMS ia64 ia64-hp-openvms*
2148 * GDBserver supports evaluation of breakpoint conditions. When
2149 support is advertised by GDBserver, GDB may be told to send the
2150 breakpoint conditions in bytecode form to GDBserver. GDBserver
2151 will only report the breakpoint trigger to GDB when its condition
2156 set mips compression
2157 show mips compression
2158 Select the compressed ISA encoding used in functions that have no symbol
2159 information available. The encoding can be set to either of:
2162 and is updated automatically from ELF file flags if available.
2164 set breakpoint condition-evaluation
2165 show breakpoint condition-evaluation
2166 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2167 GDBserver ("target"). Default option "auto" chooses the most efficient
2169 This option can improve debugger efficiency depending on the speed of the
2173 Disable auto-loading globally.
2176 Show auto-loading setting of all kinds of auto-loaded files.
2178 set auto-load gdb-scripts on|off
2179 show auto-load gdb-scripts
2180 Control auto-loading of GDB canned sequences of commands files.
2182 set auto-load python-scripts on|off
2183 show auto-load python-scripts
2184 Control auto-loading of Python script files.
2186 set auto-load local-gdbinit on|off
2187 show auto-load local-gdbinit
2188 Control loading of init file (.gdbinit) from current directory.
2190 set auto-load libthread-db on|off
2191 show auto-load libthread-db
2192 Control auto-loading of inferior specific thread debugging shared library.
2194 set auto-load scripts-directory <dir1>[:<dir2>...]
2195 show auto-load scripts-directory
2196 Set a list of directories from which to load auto-loaded scripts.
2197 Automatically loaded Python scripts and GDB scripts are located in one
2198 of the directories listed by this option.
2199 The delimiter (':' above) may differ according to the host platform.
2201 set auto-load safe-path <dir1>[:<dir2>...]
2202 show auto-load safe-path
2203 Set a list of directories from which it is safe to auto-load files.
2204 The delimiter (':' above) may differ according to the host platform.
2206 set debug auto-load on|off
2207 show debug auto-load
2208 Control display of debugging info for auto-loading the files above.
2210 set dprintf-style gdb|call|agent
2212 Control the way in which a dynamic printf is performed; "gdb"
2213 requests a GDB printf command, while "call" causes dprintf to call a
2214 function in the inferior. "agent" requests that the target agent
2215 (such as GDBserver) do the printing.
2217 set dprintf-function <expr>
2218 show dprintf-function
2219 set dprintf-channel <expr>
2220 show dprintf-channel
2221 Set the function and optional first argument to the call when using
2222 the "call" style of dynamic printf.
2224 set disconnected-dprintf on|off
2225 show disconnected-dprintf
2226 Control whether agent-style dynamic printfs continue to be in effect
2227 after GDB disconnects.
2229 * New configure options
2231 --with-auto-load-dir
2232 Configure default value for the 'set auto-load scripts-directory'
2233 setting above. It defaults to '$debugdir:$datadir/auto-load',
2234 $debugdir representing global debugging info directories (available
2235 via 'show debug-file-directory') and $datadir representing GDB's data
2236 directory (available via 'show data-directory').
2238 --with-auto-load-safe-path
2239 Configure default value for the 'set auto-load safe-path' setting
2240 above. It defaults to the --with-auto-load-dir setting.
2242 --without-auto-load-safe-path
2243 Set 'set auto-load safe-path' to '/', effectively disabling this
2246 * New remote packets
2248 z0/z1 conditional breakpoints extension
2250 The z0/z1 breakpoint insertion packets have been extended to carry
2251 a list of conditional expressions over to the remote stub depending on the
2252 condition evaluation mode. The use of this extension can be controlled
2253 via the "set remote conditional-breakpoints-packet" command.
2257 Specify the signals which the remote stub may pass to the debugged
2258 program without GDB involvement.
2260 * New command line options
2262 --init-command=FILE, -ix Like --command, -x but execute it
2263 before loading inferior.
2264 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2265 execute it before loading inferior.
2267 *** Changes in GDB 7.4
2269 * GDB now handles ambiguous linespecs more consistently; the existing
2270 FILE:LINE support has been expanded to other types of linespecs. A
2271 breakpoint will now be set on all matching locations in all
2272 inferiors, and locations will be added or removed according to
2275 * GDB now allows you to skip uninteresting functions and files when
2276 stepping with the "skip function" and "skip file" commands.
2278 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2279 and "show remote hardware-watchpoint-length-limit". These allows to
2280 set or show the maximum length limit (in bytes) of a remote
2281 target hardware watchpoint.
2283 This allows e.g. to use "unlimited" hardware watchpoints with the
2284 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2285 watchpoints are slower than real hardware watchpoints but are
2286 significantly faster than gdb software watchpoints.
2290 ** The register_pretty_printer function in module gdb.printing now takes
2291 an optional `replace' argument. If True, the new printer replaces any
2294 ** The "maint set python print-stack on|off" command has been
2295 deprecated and will be deleted in GDB 7.5.
2296 A new command: "set python print-stack none|full|message" has
2297 replaced it. Additionally, the default for "print-stack" is
2298 now "message", which just prints the error message without
2301 ** A prompt substitution hook (prompt_hook) is now available to the
2304 ** A new Python module, gdb.prompt has been added to the GDB Python
2305 modules library. This module provides functionality for
2306 escape sequences in prompts (used by set/show
2307 extended-prompt). These escape sequences are replaced by their
2308 corresponding value.
2310 ** Python commands and convenience-functions located in
2311 'data-directory'/python/gdb/command and
2312 'data-directory'/python/gdb/function are now automatically loaded
2315 ** Blocks now provide four new attributes. global_block and
2316 static_block will return the global and static blocks
2317 respectively. is_static and is_global are boolean attributes
2318 that indicate if the block is one of those two types.
2320 ** Symbols now provide the "type" attribute, the type of the symbol.
2322 ** The "gdb.breakpoint" function has been deprecated in favor of
2325 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2326 of a function. This class is based on the "finish" command
2327 available in the CLI.
2329 ** Type objects for struct and union types now allow access to
2330 the fields using standard Python dictionary (mapping) methods.
2331 For example, "some_type['myfield']" now works, as does
2332 "some_type.items()".
2334 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2337 ** A new function, "deep_items" has been added to the gdb.types
2338 module in the GDB Python modules library. This function returns
2339 an iterator over the fields of a struct or union type. Unlike
2340 the standard Python "iteritems" method, it will recursively traverse
2341 any anonymous fields.
2345 ** "*stopped" events can report several new "reason"s, such as
2348 ** Breakpoint changes are now notified using new async records, like
2349 "=breakpoint-modified".
2351 ** New command -ada-task-info.
2353 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2354 $sdir specifies the default system locations of shared libraries.
2355 $pdir specifies the directory where the libpthread used by the application
2358 GDB no longer looks in $sdir and $pdir after it has searched the directories
2359 mentioned in libthread-db-search-path. If you want to search those
2360 directories, they must be specified in libthread-db-search-path.
2361 The default value of libthread-db-search-path on GNU/Linux and Solaris
2362 systems is now "$sdir:$pdir".
2364 $pdir is not supported by gdbserver, it is currently ignored.
2365 $sdir is supported by gdbserver.
2367 * New configure option --with-iconv-bin.
2368 When using the internationalization support like the one in the GNU C
2369 library, GDB will invoke the "iconv" program to get a list of supported
2370 character sets. If this program lives in a non-standard location, one can
2371 use this option to specify where to find it.
2373 * When natively debugging programs on PowerPC BookE processors running
2374 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2375 watchpoints, which specify a mask in addition to an address to watch.
2376 The mask specifies that some bits of an address (the bits which are
2377 reset in the mask) should be ignored when matching the address accessed
2378 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2379 section in the user manual for more details.
2381 * The new option --once causes GDBserver to stop listening for connections once
2382 the first connection is made. The listening port used by GDBserver will
2383 become available after that.
2385 * New commands "info macros" and "alias" have been added.
2387 * New function parameters suffix @entry specifies value of function parameter
2388 at the time the function got called. Entry values are available only since
2394 "!" is now an alias of the "shell" command.
2395 Note that no space is needed between "!" and SHELL COMMAND.
2399 watch EXPRESSION mask MASK_VALUE
2400 The watch command now supports the mask argument which allows creation
2401 of masked watchpoints, if the current architecture supports this feature.
2403 info auto-load-scripts [REGEXP]
2404 This command was formerly named "maintenance print section-scripts".
2405 It is now generally useful and is no longer a maintenance-only command.
2407 info macro [-all] [--] MACRO
2408 The info macro command has new options `-all' and `--'. The first for
2409 printing all definitions of a macro. The second for explicitly specifying
2410 the end of arguments and the beginning of the macro name in case the macro
2411 name starts with a hyphen.
2413 collect[/s] EXPRESSIONS
2414 The tracepoint collect command now takes an optional modifier "/s"
2415 that directs it to dereference pointer-to-character types and
2416 collect the bytes of memory up to a zero byte. The behavior is
2417 similar to what you see when you use the regular print command on a
2418 string. An optional integer following the "/s" sets a bound on the
2419 number of bytes that will be collected.
2422 The trace start command now interprets any supplied arguments as a
2423 note to be recorded with the trace run, with an effect similar to
2424 setting the variable trace-notes.
2427 The trace stop command now interprets any arguments as a note to be
2428 mentioned along with the tstatus report that the trace was stopped
2429 with a command. The effect is similar to setting the variable
2432 * Tracepoints can now be enabled and disabled at any time after a trace
2433 experiment has been started using the standard "enable" and "disable"
2434 commands. It is now possible to start a trace experiment with no enabled
2435 tracepoints; GDB will display a warning, but will allow the experiment to
2436 begin, assuming that tracepoints will be enabled as needed while the trace
2439 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2440 locations with 4-byte instructions, when they were previously
2441 limited to locations with instructions of 5 bytes or longer.
2445 set debug dwarf2-read
2446 show debug dwarf2-read
2447 Turns on or off display of debugging messages related to reading
2448 DWARF debug info. The default is off.
2450 set debug symtab-create
2451 show debug symtab-create
2452 Turns on or off display of debugging messages related to symbol table
2453 creation. The default is off.
2456 show extended-prompt
2457 Set the GDB prompt, and allow escape sequences to be inserted to
2458 display miscellaneous information (see 'help set extended-prompt'
2459 for the list of sequences). This prompt (and any information
2460 accessed through the escape sequences) is updated every time the
2461 prompt is displayed.
2463 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2464 show print entry-values
2465 Set printing of frame argument values at function entry. In some cases
2466 GDB can determine the value of function argument which was passed by the
2467 function caller, even if the value was modified inside the called function.
2469 set debug entry-values
2470 show debug entry-values
2471 Control display of debugging info for determining frame argument values at
2472 function entry and virtual tail call frames.
2474 set basenames-may-differ
2475 show basenames-may-differ
2476 Set whether a source file may have multiple base names.
2477 (A "base name" is the name of a file with the directory part removed.
2478 Example: The base name of "/home/user/hello.c" is "hello.c".)
2479 If set, GDB will canonicalize file names (e.g., expand symlinks)
2480 before comparing them. Canonicalization is an expensive operation,
2481 but it allows the same file be known by more than one base name.
2482 If not set (the default), all source files are assumed to have just
2483 one base name, and gdb will do file name comparisons more efficiently.
2489 Set a user name and notes for the current and any future trace runs.
2490 This is useful for long-running and/or disconnected traces, to
2491 inform others (or yourself) as to who is running the trace, supply
2492 contact information, or otherwise explain what is going on.
2494 set trace-stop-notes
2495 show trace-stop-notes
2496 Set a note attached to the trace run, that is displayed when the
2497 trace has been stopped by a tstop command. This is useful for
2498 instance as an explanation, if you are stopping a trace run that was
2499 started by someone else.
2501 * New remote packets
2505 Dynamically enable a tracepoint in a started trace experiment.
2509 Dynamically disable a tracepoint in a started trace experiment.
2513 Set the user and notes of the trace run.
2517 Query the current status of a tracepoint.
2521 Query the minimum length of instruction at which a fast tracepoint may
2524 * Dcache size (number of lines) and line-size are now runtime-configurable
2525 via "set dcache line" and "set dcache line-size" commands.
2529 Texas Instruments TMS320C6x tic6x-*-*
2533 Renesas RL78 rl78-*-elf
2535 *** Changes in GDB 7.3.1
2537 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2539 *** Changes in GDB 7.3
2541 * GDB has a new command: "thread find [REGEXP]".
2542 It finds the thread id whose name, target id, or thread extra info
2543 matches the given regular expression.
2545 * The "catch syscall" command now works on mips*-linux* targets.
2547 * The -data-disassemble MI command now supports modes 2 and 3 for
2548 dumping the instruction opcodes.
2550 * New command line options
2552 -data-directory DIR Specify DIR as the "data-directory".
2553 This is mostly for testing purposes.
2555 * The "maint set python auto-load on|off" command has been renamed to
2556 "set auto-load-scripts on|off".
2558 * GDB has a new command: "set directories".
2559 It is like the "dir" command except that it replaces the
2560 source path list instead of augmenting it.
2562 * GDB now understands thread names.
2564 On GNU/Linux, "info threads" will display the thread name as set by
2565 prctl or pthread_setname_np.
2567 There is also a new command, "thread name", which can be used to
2568 assign a name internally for GDB to display.
2571 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2572 has been integrated into GDB.
2576 ** The function gdb.Write now accepts an optional keyword 'stream'.
2577 This keyword, when provided, will direct the output to either
2578 stdout, stderr, or GDB's logging output.
2580 ** Parameters can now be be sub-classed in Python, and in particular
2581 you may implement the get_set_doc and get_show_doc functions.
2582 This improves how Parameter set/show documentation is processed
2583 and allows for more dynamic content.
2585 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2586 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2587 have an is_valid method.
2589 ** Breakpoints can now be sub-classed in Python, and in particular
2590 you may implement a 'stop' function that is executed each time
2591 the inferior reaches that breakpoint.
2593 ** New function gdb.lookup_global_symbol looks up a global symbol.
2595 ** GDB values in Python are now callable if the value represents a
2596 function. For example, if 'some_value' represents a function that
2597 takes two integer parameters and returns a value, you can call
2598 that function like so:
2600 result = some_value (10,20)
2602 ** Module gdb.types has been added.
2603 It contains a collection of utilities for working with gdb.Types objects:
2604 get_basic_type, has_field, make_enum_dict.
2606 ** Module gdb.printing has been added.
2607 It contains utilities for writing and registering pretty-printers.
2608 New classes: PrettyPrinter, SubPrettyPrinter,
2609 RegexpCollectionPrettyPrinter.
2610 New function: register_pretty_printer.
2612 ** New commands "info pretty-printers", "enable pretty-printer" and
2613 "disable pretty-printer" have been added.
2615 ** gdb.parameter("directories") is now available.
2617 ** New function gdb.newest_frame returns the newest frame in the
2620 ** The gdb.InferiorThread class has a new "name" attribute. This
2621 holds the thread's name.
2623 ** Python Support for Inferior events.
2624 Python scripts can add observers to be notified of events
2625 occurring in the process being debugged.
2626 The following events are currently supported:
2627 - gdb.events.cont Continue event.
2628 - gdb.events.exited Inferior exited event.
2629 - gdb.events.stop Signal received, and Breakpoint hit events.
2633 ** GDB now puts template parameters in scope when debugging in an
2634 instantiation. For example, if you have:
2636 template<int X> int func (void) { return X; }
2638 then if you step into func<5>, "print X" will show "5". This
2639 feature requires proper debuginfo support from the compiler; it
2640 was added to GCC 4.5.
2642 ** The motion commands "next", "finish", "until", and "advance" now
2643 work better when exceptions are thrown. In particular, GDB will
2644 no longer lose control of the inferior; instead, the GDB will
2645 stop the inferior at the point at which the exception is caught.
2646 This functionality requires a change in the exception handling
2647 code that was introduced in GCC 4.5.
2649 * GDB now follows GCC's rules on accessing volatile objects when
2650 reading or writing target state during expression evaluation.
2651 One notable difference to prior behavior is that "print x = 0"
2652 no longer generates a read of x; the value of the assignment is
2653 now always taken directly from the value being assigned.
2655 * GDB now has some support for using labels in the program's source in
2656 linespecs. For instance, you can use "advance label" to continue
2657 execution to a label.
2659 * GDB now has support for reading and writing a new .gdb_index
2660 section. This section holds a fast index of DWARF debugging
2661 information and can be used to greatly speed up GDB startup and
2662 operation. See the documentation for `save gdb-index' for details.
2664 * The "watch" command now accepts an optional "-location" argument.
2665 When used, this causes GDB to watch the memory referred to by the
2666 expression. Such a watchpoint is never deleted due to it going out
2669 * GDB now supports thread debugging of core dumps on GNU/Linux.
2671 GDB now activates thread debugging using the libthread_db library
2672 when debugging GNU/Linux core dumps, similarly to when debugging
2673 live processes. As a result, when debugging a core dump file, GDB
2674 is now able to display pthread_t ids of threads. For example, "info
2675 threads" shows the same output as when debugging the process when it
2676 was live. In earlier releases, you'd see something like this:
2679 * 1 LWP 6780 main () at main.c:10
2681 While now you see this:
2684 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2686 It is also now possible to inspect TLS variables when debugging core
2689 When debugging a core dump generated on a machine other than the one
2690 used to run GDB, you may need to point GDB at the correct
2691 libthread_db library with the "set libthread-db-search-path"
2692 command. See the user manual for more details on this command.
2694 * When natively debugging programs on PowerPC BookE processors running
2695 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2696 which stop execution of the inferior whenever it executes an instruction
2697 at any address within the specified range. See the "PowerPC Embedded"
2698 section in the user manual for more details.
2700 * New features in the GDB remote stub, GDBserver
2702 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2703 and i686 LynxOS (version 5.x).
2705 ** GDBserver is now supported on Blackfin Linux.
2707 * New native configurations
2709 ia64 HP-UX ia64-*-hpux*
2713 Analog Devices, Inc. Blackfin Processor bfin-*
2715 * Ada task switching is now supported on sparc-elf targets when
2716 debugging a program using the Ravenscar Profile. For more information,
2717 see the "Tasking Support when using the Ravenscar Profile" section
2718 in the GDB user manual.
2720 * Guile support was removed.
2722 * New features in the GNU simulator
2724 ** The --map-info flag lists all known core mappings.
2726 ** CFI flashes may be simulated via the "cfi" device.
2728 *** Changes in GDB 7.2
2730 * Shared library support for remote targets by default
2732 When GDB is configured for a generic, non-OS specific target, like
2733 for example, --target=arm-eabi or one of the many *-*-elf targets,
2734 GDB now queries remote stubs for loaded shared libraries using the
2735 `qXfer:libraries:read' packet. Previously, shared library support
2736 was always disabled for such configurations.
2740 ** Argument Dependent Lookup (ADL)
2742 In C++ ADL lookup directs function search to the namespaces of its
2743 arguments even if the namespace has not been imported.
2753 Here the compiler will search for `foo' in the namespace of 'b'
2754 and find A::foo. GDB now supports this. This construct is commonly
2755 used in the Standard Template Library for operators.
2757 ** Improved User Defined Operator Support
2759 In addition to member operators, GDB now supports lookup of operators
2760 defined in a namespace and imported with a `using' directive, operators
2761 defined in the global scope, operators imported implicitly from an
2762 anonymous namespace, and the ADL operators mentioned in the previous
2764 GDB now also supports proper overload resolution for all the previously
2765 mentioned flavors of operators.
2767 ** static const class members
2769 Printing of static const class members that are initialized in the
2770 class definition has been fixed.
2772 * Windows Thread Information Block access.
2774 On Windows targets, GDB now supports displaying the Windows Thread
2775 Information Block (TIB) structure. This structure is visible either
2776 by using the new command `info w32 thread-information-block' or, by
2777 dereferencing the new convenience variable named `$_tlb', a
2778 thread-specific pointer to the TIB. This feature is also supported
2779 when remote debugging using GDBserver.
2781 * Static tracepoints
2783 Static tracepoints are calls in the user program into a tracing
2784 library. One such library is a port of the LTTng kernel tracer to
2785 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2786 When debugging with GDBserver, GDB now supports combining the GDB
2787 tracepoint machinery with such libraries. For example: the user can
2788 use GDB to probe a static tracepoint marker (a call from the user
2789 program into the tracing library) with the new "strace" command (see
2790 "New commands" below). This creates a "static tracepoint" in the
2791 breakpoint list, that can be manipulated with the same feature set
2792 as fast and regular tracepoints. E.g., collect registers, local and
2793 global variables, collect trace state variables, and define
2794 tracepoint conditions. In addition, the user can collect extra
2795 static tracepoint marker specific data, by collecting the new
2796 $_sdata internal variable. When analyzing the trace buffer, you can
2797 inspect $_sdata like any other variable available to GDB. For more
2798 information, see the "Tracepoints" chapter in GDB user manual. New
2799 remote packets have been defined to support static tracepoints, see
2800 the "New remote packets" section below.
2802 * Better reconstruction of tracepoints after disconnected tracing
2804 GDB will attempt to download the original source form of tracepoint
2805 definitions when starting a trace run, and then will upload these
2806 upon reconnection to the target, resulting in a more accurate
2807 reconstruction of the tracepoints that are in use on the target.
2811 You can now exercise direct control over the ways that GDB can
2812 affect your program. For instance, you can disallow the setting of
2813 breakpoints, so that the program can run continuously (assuming
2814 non-stop mode). In addition, the "observer" variable is available
2815 to switch all of the different controls; in observer mode, GDB
2816 cannot affect the target's behavior at all, which is useful for
2817 tasks like diagnosing live systems in the field.
2819 * The new convenience variable $_thread holds the number of the
2822 * New remote packets
2826 Return the address of the Windows Thread Information Block of a given thread.
2830 In response to several of the tracepoint packets, the target may now
2831 also respond with a number of intermediate `qRelocInsn' request
2832 packets before the final result packet, to have GDB handle
2833 relocating an instruction to execute at a different address. This
2834 is particularly useful for stubs that support fast tracepoints. GDB
2835 reports support for this feature in the qSupported packet.
2839 List static tracepoint markers in the target program.
2843 List static tracepoint markers at a given address in the target
2846 qXfer:statictrace:read
2848 Read the static trace data collected (by a `collect $_sdata'
2849 tracepoint action). The remote stub reports support for this packet
2850 to gdb's qSupported query.
2854 Send the current settings of GDB's permission flags.
2858 Send part of the source (textual) form of a tracepoint definition,
2859 which includes location, conditional, and action list.
2861 * The source command now accepts a -s option to force searching for the
2862 script in the source search path even if the script name specifies
2865 * New features in the GDB remote stub, GDBserver
2867 - GDBserver now support tracepoints (including fast tracepoints, and
2868 static tracepoints). The feature is currently supported by the
2869 i386-linux and amd64-linux builds. See the "Tracepoints support
2870 in gdbserver" section in the manual for more information.
2872 GDBserver JIT compiles the tracepoint's conditional agent
2873 expression bytecode into native code whenever possible for low
2874 overhead dynamic tracepoints conditionals. For such tracepoints,
2875 an expression that examines program state is evaluated when the
2876 tracepoint is reached, in order to determine whether to capture
2877 trace data. If the condition is simple and false, processing the
2878 tracepoint finishes very quickly and no data is gathered.
2880 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2881 for static tracepoints support.
2883 - GDBserver now supports x86_64 Windows 64-bit debugging.
2885 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2886 it understands register description.
2888 * The --batch flag now disables pagination and queries.
2890 * X86 general purpose registers
2892 GDB now supports reading/writing byte, word and double-word x86
2893 general purpose registers directly. This means you can use, say,
2894 $ah or $ax to refer, respectively, to the byte register AH and
2895 16-bit word register AX that are actually portions of the 32-bit
2896 register EAX or 64-bit register RAX.
2898 * The `commands' command now accepts a range of breakpoints to modify.
2899 A plain `commands' following a command that creates multiple
2900 breakpoints affects all the breakpoints set by that command. This
2901 applies to breakpoints set by `rbreak', and also applies when a
2902 single `break' command creates multiple breakpoints (e.g.,
2903 breakpoints on overloaded c++ functions).
2905 * The `rbreak' command now accepts a filename specification as part of
2906 its argument, limiting the functions selected by the regex to those
2907 in the specified file.
2909 * Support for remote debugging Windows and SymbianOS shared libraries
2910 from Unix hosts has been improved. Non Windows GDB builds now can
2911 understand target reported file names that follow MS-DOS based file
2912 system semantics, such as file names that include drive letters and
2913 use the backslash character as directory separator. This makes it
2914 possible to transparently use the "set sysroot" and "set
2915 solib-search-path" on Unix hosts to point as host copies of the
2916 target's shared libraries. See the new command "set
2917 target-file-system-kind" described below, and the "Commands to
2918 specify files" section in the user manual for more information.
2922 eval template, expressions...
2923 Convert the values of one or more expressions under the control
2924 of the string template to a command line, and call it.
2926 set target-file-system-kind unix|dos-based|auto
2927 show target-file-system-kind
2928 Set or show the assumed file system kind for target reported file
2931 save breakpoints <filename>
2932 Save all current breakpoint definitions to a file suitable for use
2933 in a later debugging session. To read the saved breakpoint
2934 definitions, use the `source' command.
2936 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2939 info static-tracepoint-markers
2940 Display information about static tracepoint markers in the target.
2942 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2943 Define a static tracepoint by probing a marker at the given
2944 function, line, address, or marker ID.
2948 Enable and disable observer mode.
2950 set may-write-registers on|off
2951 set may-write-memory on|off
2952 set may-insert-breakpoints on|off
2953 set may-insert-tracepoints on|off
2954 set may-insert-fast-tracepoints on|off
2955 set may-interrupt on|off
2956 Set individual permissions for GDB effects on the target. Note that
2957 some of these settings can have undesirable or surprising
2958 consequences, particularly when changed in the middle of a session.
2959 For instance, disabling the writing of memory can prevent
2960 breakpoints from being inserted, cause single-stepping to fail, or
2961 even crash your program, if you disable after breakpoints have been
2962 inserted. However, GDB should not crash.
2964 set record memory-query on|off
2965 show record memory-query
2966 Control whether to stop the inferior if memory changes caused
2967 by an instruction cannot be recorded.
2972 The disassemble command now supports "start,+length" form of two arguments.
2976 ** GDB now provides a new directory location, called the python directory,
2977 where Python scripts written for GDB can be installed. The location
2978 of that directory is <data-directory>/python, where <data-directory>
2979 is the GDB data directory. For more details, see section `Scripting
2980 GDB using Python' in the manual.
2982 ** The GDB Python API now has access to breakpoints, symbols, symbol
2983 tables, program spaces, inferiors, threads and frame's code blocks.
2984 Additionally, GDB Parameters can now be created from the API, and
2985 manipulated via set/show in the CLI.
2987 ** New functions gdb.target_charset, gdb.target_wide_charset,
2988 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2990 ** New exception gdb.GdbError.
2992 ** Pretty-printers are now also looked up in the current program space.
2994 ** Pretty-printers can now be individually enabled and disabled.
2996 ** GDB now looks for names of Python scripts to auto-load in a
2997 special section named `.debug_gdb_scripts', in addition to looking
2998 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3000 * Tracepoint actions were unified with breakpoint commands. In particular,
3001 there are no longer differences in "info break" output for breakpoints and
3002 tracepoints and the "commands" command can be used for both tracepoints and
3003 regular breakpoints.
3007 ARM Symbian arm*-*-symbianelf*
3009 * D language support.
3010 GDB now supports debugging programs written in the D programming
3013 * GDB now supports the extended ptrace interface for PowerPC which is
3014 available since Linux kernel version 2.6.34. This automatically enables
3015 any hardware breakpoints and additional hardware watchpoints available in
3016 the processor. The old ptrace interface exposes just one hardware
3017 watchpoint and no hardware breakpoints.
3019 * GDB is now able to use the Data Value Compare (DVC) register available on
3020 embedded PowerPC processors to implement in hardware simple watchpoint
3021 conditions of the form:
3023 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3025 This works in native GDB running on Linux kernels with the extended ptrace
3026 interface mentioned above.
3028 *** Changes in GDB 7.1
3032 ** Namespace Support
3034 GDB now supports importing of namespaces in C++. This enables the
3035 user to inspect variables from imported namespaces. Support for
3036 namepace aliasing has also been added. So, if a namespace is
3037 aliased in the current scope (e.g. namepace C=A; ) the user can
3038 print variables using the alias (e.g. (gdb) print C::x).
3042 All known bugs relating to the printing of virtual base class were
3043 fixed. It is now possible to call overloaded static methods using a
3048 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3049 and reinterpret_cast<> are now handled by the C++ expression parser.
3053 Xilinx MicroBlaze microblaze-*-*
3058 Xilinx MicroBlaze microblaze
3061 * Multi-program debugging.
3063 GDB now has support for multi-program (a.k.a. multi-executable or
3064 multi-exec) debugging. This allows for debugging multiple inferiors
3065 simultaneously each running a different program under the same GDB
3066 session. See "Debugging Multiple Inferiors and Programs" in the
3067 manual for more information. This implied some user visible changes
3068 in the multi-inferior support. For example, "info inferiors" now
3069 lists inferiors that are not running yet or that have exited
3070 already. See also "New commands" and "New options" below.
3072 * New tracing features
3074 GDB's tracepoint facility now includes several new features:
3076 ** Trace state variables
3078 GDB tracepoints now include support for trace state variables, which
3079 are variables managed by the target agent during a tracing
3080 experiment. They are useful for tracepoints that trigger each
3081 other, so for instance one tracepoint can count hits in a variable,
3082 and then a second tracepoint has a condition that is true when the
3083 count reaches a particular value. Trace state variables share the
3084 $-syntax of GDB convenience variables, and can appear in both
3085 tracepoint actions and condition expressions. Use the "tvariable"
3086 command to create, and "info tvariables" to view; see "Trace State
3087 Variables" in the manual for more detail.
3091 GDB now includes an option for defining fast tracepoints, which
3092 targets may implement more efficiently, such as by installing a jump
3093 into the target agent rather than a trap instruction. The resulting
3094 speedup can be by two orders of magnitude or more, although the
3095 tradeoff is that some program locations on some target architectures
3096 might not allow fast tracepoint installation, for instance if the
3097 instruction to be replaced is shorter than the jump. To request a
3098 fast tracepoint, use the "ftrace" command, with syntax identical to
3099 the regular trace command.
3101 ** Disconnected tracing
3103 It is now possible to detach GDB from the target while it is running
3104 a trace experiment, then reconnect later to see how the experiment
3105 is going. In addition, a new variable disconnected-tracing lets you
3106 tell the target agent whether to continue running a trace if the
3107 connection is lost unexpectedly.
3111 GDB now has the ability to save the trace buffer into a file, and
3112 then use that file as a target, similarly to you can do with
3113 corefiles. You can select trace frames, print data that was
3114 collected in them, and use tstatus to display the state of the
3115 tracing run at the moment that it was saved. To create a trace
3116 file, use "tsave <filename>", and to use it, do "target tfile
3119 ** Circular trace buffer
3121 You can ask the target agent to handle the trace buffer as a
3122 circular buffer, discarding the oldest trace frames to make room for
3123 newer ones, by setting circular-trace-buffer to on. This feature may
3124 not be available for all target agents.
3129 The disassemble command, when invoked with two arguments, now requires
3130 the arguments to be comma-separated.
3133 The info variables command now displays variable definitions. Files
3134 which only declare a variable are not shown.
3137 The source command is now capable of sourcing Python scripts.
3138 This feature is dependent on the debugger being build with Python
3141 Related to this enhancement is also the introduction of a new command
3142 "set script-extension" (see below).
3144 * New commands (for set/show, see "New options" below)
3146 record save [<FILENAME>]
3147 Save a file (in core file format) containing the process record
3148 execution log for replay debugging at a later time.
3150 record restore <FILENAME>
3151 Restore the process record execution log that was saved at an
3152 earlier time, for replay debugging.
3154 add-inferior [-copies <N>] [-exec <FILENAME>]
3157 clone-inferior [-copies <N>] [ID]
3158 Make a new inferior ready to execute the same program another
3159 inferior has loaded.
3164 maint info program-spaces
3165 List the program spaces loaded into GDB.
3167 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3168 show remote interrupt-sequence
3169 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3170 as the sequence to the remote target in order to interrupt the execution.
3171 Ctrl-C is a default. Some system prefers BREAK which is high level of
3172 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3173 Magic SysRq g. It is BREAK signal and character 'g'.
3175 set remote interrupt-on-connect [on | off]
3176 show remote interrupt-on-connect
3177 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3178 remote target when gdb connects to it. This is needed when you debug
3181 set remotebreak [on | off]
3183 Deprecated. Use "set/show remote interrupt-sequence" instead.
3185 tvariable $NAME [ = EXP ]
3186 Create or modify a trace state variable.
3189 List trace state variables and their values.
3191 delete tvariable $NAME ...
3192 Delete one or more trace state variables.
3195 Evaluate the given expressions without collecting anything into the
3196 trace buffer. (Valid in tracepoint actions only.)
3198 ftrace FN / FILE:LINE / *ADDR
3199 Define a fast tracepoint at the given function, line, or address.
3201 * New expression syntax
3203 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3204 GDB now parses 0b101010 identically with 42.
3208 set follow-exec-mode new|same
3209 show follow-exec-mode
3210 Control whether GDB reuses the same inferior across an exec call or
3211 creates a new one. This is useful to be able to restart the old
3212 executable after the inferior having done an exec call.
3214 set default-collect EXPR, ...
3215 show default-collect
3216 Define a list of expressions to be collected at each tracepoint.
3217 This is a useful way to ensure essential items are not overlooked,
3218 such as registers or a critical global variable.
3220 set disconnected-tracing
3221 show disconnected-tracing
3222 If set to 1, the target is instructed to continue tracing if it
3223 loses its connection to GDB. If 0, the target is to stop tracing
3226 set circular-trace-buffer
3227 show circular-trace-buffer
3228 If set to on, the target is instructed to use a circular trace buffer
3229 and discard the oldest trace frames instead of stopping the trace due
3230 to a full trace buffer. If set to off, the trace stops when the buffer
3231 fills up. Some targets may not support this.
3233 set script-extension off|soft|strict
3234 show script-extension
3235 If set to "off", the debugger does not perform any script language
3236 recognition, and all sourced files are assumed to be GDB scripts.
3237 If set to "soft" (the default), files are sourced according to
3238 filename extension, falling back to GDB scripts if the first
3240 If set to "strict", files are sourced according to filename extension.
3242 set ada trust-PAD-over-XVS on|off
3243 show ada trust-PAD-over-XVS
3244 If off, activate a workaround against a bug in the debugging information
3245 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3246 the GCC sources for more information about the GNAT encoding and
3247 PAD types in particular). It is always safe to set this option to
3248 off, but this introduces a slight performance penalty. The default
3251 * Python API Improvements
3253 ** GDB provides the new class gdb.LazyString. This is useful in
3254 some pretty-printing cases. The new method gdb.Value.lazy_string
3255 provides a simple way to create objects of this type.
3257 ** The fields returned by gdb.Type.fields now have an
3258 `is_base_class' attribute.
3260 ** The new method gdb.Type.range returns the range of an array type.
3262 ** The new method gdb.parse_and_eval can be used to parse and
3263 evaluate an expression.
3265 * New remote packets
3268 Define a trace state variable.
3271 Get the current value of a trace state variable.
3274 Set desired tracing behavior upon disconnection.
3277 Set the trace buffer to be linear or circular.
3280 Get data about the tracepoints currently in use.
3284 Process record now works correctly with hardware watchpoints.
3286 Multiple bug fixes have been made to the mips-irix port, making it
3287 much more reliable. In particular:
3288 - Debugging threaded applications is now possible again. Previously,
3289 GDB would hang while starting the program, or while waiting for
3290 the program to stop at a breakpoint.
3291 - Attaching to a running process no longer hangs.
3292 - An error occurring while loading a core file has been fixed.
3293 - Changing the value of the PC register now works again. This fixes
3294 problems observed when using the "jump" command, or when calling
3295 a function from GDB, or even when assigning a new value to $pc.
3296 - With the "finish" and "return" commands, the return value for functions
3297 returning a small array is now correctly printed.
3298 - It is now possible to break on shared library code which gets executed
3299 during a shared library init phase (code executed while executing
3300 their .init section). Previously, the breakpoint would have no effect.
3301 - GDB is now able to backtrace through the signal handler for
3302 non-threaded programs.
3304 PIE (Position Independent Executable) programs debugging is now supported.
3305 This includes debugging execution of PIC (Position Independent Code) shared
3306 libraries although for that, it should be possible to run such libraries as an
3309 *** Changes in GDB 7.0
3311 * GDB now has an interface for JIT compilation. Applications that
3312 dynamically generate code can create symbol files in memory and register
3313 them with GDB. For users, the feature should work transparently, and
3314 for JIT developers, the interface is documented in the GDB manual in the
3315 "JIT Compilation Interface" chapter.
3317 * Tracepoints may now be conditional. The syntax is as for
3318 breakpoints; either an "if" clause appended to the "trace" command,
3319 or the "condition" command is available. GDB sends the condition to
3320 the target for evaluation using the same bytecode format as is used
3321 for tracepoint actions.
3323 * The disassemble command now supports: an optional /r modifier, print the
3324 raw instructions in hex as well as in symbolic form, and an optional /m
3325 modifier to print mixed source+assembly.
3327 * Process record and replay
3329 In a architecture environment that supports ``process record and
3330 replay'', ``process record and replay'' target can record a log of
3331 the process execution, and replay it with both forward and reverse
3334 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3335 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3336 set execution-direction {forward|reverse}, for targets that support
3339 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3340 feature is available with a native GDB running on kernel version
3343 * GDB now has support for multi-byte and wide character sets on the
3344 target. Strings whose character type is wchar_t, char16_t, or
3345 char32_t are now correctly printed. GDB supports wide- and unicode-
3346 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3347 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3348 `printf'. This feature requires iconv to work properly; if your
3349 system does not have a working iconv, GDB can use GNU libiconv. See
3350 the installation instructions for more information.
3352 * GDB now supports automatic retrieval of shared library files from
3353 remote targets. To use this feature, specify a system root that begins
3354 with the `remote:' prefix, either via the `set sysroot' command or via
3355 the `--with-sysroot' configure-time option.
3357 * "info sharedlibrary" now takes an optional regex of libraries to show,
3358 and it now reports if a shared library has no debugging information.
3360 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3361 now complete on file names.
3363 * When completing in expressions, gdb will attempt to limit
3364 completions to allowable structure or union fields, where appropriate.
3365 For instance, consider:
3367 # struct example { int f1; double f2; };
3368 # struct example variable;
3371 If the user types TAB at the end of this command line, the available
3372 completions will be "f1" and "f2".
3374 * Inlined functions are now supported. They show up in backtraces, and
3375 the "step", "next", and "finish" commands handle them automatically.
3377 * GDB now supports the token-splicing (##) and stringification (#)
3378 operators when expanding macros. It also supports variable-arity
3381 * GDB now supports inspecting extra signal information, exported by
3382 the new $_siginfo convenience variable. The feature is currently
3383 implemented on linux ARM, i386 and amd64.
3385 * GDB can now display the VFP floating point registers and NEON vector
3386 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3387 can provide these registers (requires Linux 2.6.30 or later). Remote
3388 and simulator targets may also provide them.
3390 * New remote packets
3393 Search memory for a sequence of bytes.
3396 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3397 operation over reliable transport links. Use of this packet is
3398 controlled by the `set remote noack-packet' command.
3401 Kill the process with the specified process ID. Use this in preference
3402 to `k' when multiprocess protocol extensions are supported.
3405 Obtains additional operating system information
3409 Read or write additional signal information.
3411 * Removed remote protocol undocumented extension
3413 An undocumented extension to the remote protocol's `S' stop reply
3414 packet that permited the stub to pass a process id was removed.
3415 Remote servers should use the `T' stop reply packet instead.
3417 * GDB now supports multiple function calling conventions according to the
3418 DWARF-2 DW_AT_calling_convention function attribute.
3420 * The SH target utilizes the aforementioned change to distinguish between gcc
3421 and Renesas calling convention. It also adds the new CLI commands
3422 `set/show sh calling-convention'.
3424 * GDB can now read compressed debug sections, as produced by GNU gold
3425 with the --compress-debug-sections=zlib flag.
3427 * 64-bit core files are now supported on AIX.
3429 * Thread switching is now supported on Tru64.
3431 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3432 which will be allocated using malloc later in program execution.
3434 * The qXfer:libraries:read remote procotol packet now allows passing a
3435 list of section offsets.
3437 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3438 conditions handling signals delivered during attach or thread creation
3439 have also been fixed.
3441 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3442 From the user's standpoint, all unqualified instances of True and False
3443 are treated as the standard definitions, regardless of context.
3445 * GDB now parses C++ symbol and type names more flexibly. For
3448 template<typename T> class C { };
3451 GDB will now correctly handle all of:
3453 ptype C<char const *>
3454 ptype C<char const*>
3455 ptype C<const char *>
3456 ptype C<const char*>
3458 * New features in the GDB remote stub, gdbserver
3460 - The "--wrapper" command-line argument tells gdbserver to use a
3461 wrapper program to launch programs for debugging.
3463 - On PowerPC and S/390 targets, it is now possible to use a single
3464 gdbserver executable to debug both 32-bit and 64-bit programs.
3465 (This requires gdbserver itself to be built as a 64-bit executable.)
3467 - gdbserver uses the new noack protocol mode for TCP connections to
3468 reduce communications latency, if also supported and enabled in GDB.
3470 - Support for the sparc64-linux-gnu target is now included in
3473 - The amd64-linux build of gdbserver now supports debugging both
3474 32-bit and 64-bit programs.
3476 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3477 now support hardware watchpoints, and will use them automatically
3482 GDB now has support for scripting using Python. Whether this is
3483 available is determined at configure time.
3485 New GDB commands can now be written in Python.
3487 * Ada tasking support
3489 Ada tasks can now be inspected in GDB. The following commands have
3493 Print the list of Ada tasks.
3495 Print detailed information about task number N.
3497 Print the task number of the current task.
3499 Switch the context of debugging to task number N.
3501 * Support for user-defined prefixed commands. The "define" command can
3502 add new commands to existing prefixes, e.g. "target".
3504 * Multi-inferior, multi-process debugging.
3506 GDB now has generalized support for multi-inferior debugging. See
3507 "Debugging Multiple Inferiors" in the manual for more information.
3508 Although availability still depends on target support, the command
3509 set is more uniform now. The GNU/Linux specific multi-forks support
3510 has been migrated to this new framework. This implied some user
3511 visible changes; see "New commands" and also "Removed commands"
3514 * Target descriptions can now describe the target OS ABI. See the
3515 "Target Description Format" section in the user manual for more
3518 * Target descriptions can now describe "compatible" architectures
3519 to indicate that the target can execute applications for a different
3520 architecture in addition to those for the main target architecture.
3521 See the "Target Description Format" section in the user manual for
3524 * Multi-architecture debugging.
3526 GDB now includes general supports for debugging applications on
3527 hybrid systems that use more than one single processor architecture
3528 at the same time. Each such hybrid architecture still requires
3529 specific support to be added. The only hybrid architecture supported
3530 in this version of GDB is the Cell Broadband Engine.
3532 * GDB now supports integrated debugging of Cell/B.E. applications that
3533 use both the PPU and SPU architectures. To enable support for hybrid
3534 Cell/B.E. debugging, you need to configure GDB to support both the
3535 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3536 --enable-targets configure option.
3538 * Non-stop mode debugging.
3540 For some targets, GDB now supports an optional mode of operation in
3541 which you can examine stopped threads while other threads continue
3542 to execute freely. This is referred to as non-stop mode, with the
3543 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3544 section in the user manual for more information.
3546 To be able to support remote non-stop debugging, a remote stub needs
3547 to implement the non-stop mode remote protocol extensions, as
3548 described in the "Remote Non-Stop" section of the user manual. The
3549 GDB remote stub, gdbserver, has been adjusted to support these
3550 extensions on linux targets.
3552 * New commands (for set/show, see "New options" below)
3554 catch syscall [NAME(S) | NUMBER(S)]
3555 Catch system calls. Arguments, which should be names of system
3556 calls or their numbers, mean catch only those syscalls. Without
3557 arguments, every syscall will be caught. When the inferior issues
3558 any of the specified syscalls, GDB will stop and announce the system
3559 call, both when it is called and when its call returns. This
3560 feature is currently available with a native GDB running on the
3561 Linux Kernel, under the following architectures: x86, x86_64,
3562 PowerPC and PowerPC64.
3564 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3566 Search memory for a sequence of bytes.
3568 maint set python print-stack
3569 maint show python print-stack
3570 Show a stack trace when an error is encountered in a Python script.
3573 Invoke CODE by passing it to the Python interpreter.
3578 These allow macros to be defined, undefined, and listed
3582 Show operating system information about processes.
3585 List the inferiors currently under GDB's control.
3588 Switch focus to inferior number NUM.
3591 Detach from inferior number NUM.
3594 Kill inferior number NUM.
3598 set spu stop-on-load
3599 show spu stop-on-load
3600 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3602 set spu auto-flush-cache
3603 show spu auto-flush-cache
3604 Control whether to automatically flush the software-managed cache
3605 during Cell/B.E. debugging.
3607 set sh calling-convention
3608 show sh calling-convention
3609 Control the calling convention used when calling SH target functions.
3612 show debug timestamp
3613 Control display of timestamps with GDB debugging output.
3615 set disassemble-next-line
3616 show disassemble-next-line
3617 Control display of disassembled source lines or instructions when
3620 set remote noack-packet
3621 show remote noack-packet
3622 Set/show the use of remote protocol QStartNoAckMode packet. See above
3623 under "New remote packets."
3625 set remote query-attached-packet
3626 show remote query-attached-packet
3627 Control use of remote protocol `qAttached' (query-attached) packet.
3629 set remote read-siginfo-object
3630 show remote read-siginfo-object
3631 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3634 set remote write-siginfo-object
3635 show remote write-siginfo-object
3636 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3639 set remote reverse-continue
3640 show remote reverse-continue
3641 Control use of remote protocol 'bc' (reverse-continue) packet.
3643 set remote reverse-step
3644 show remote reverse-step
3645 Control use of remote protocol 'bs' (reverse-step) packet.
3647 set displaced-stepping
3648 show displaced-stepping
3649 Control displaced stepping mode. Displaced stepping is a way to
3650 single-step over breakpoints without removing them from the debuggee.
3651 Also known as "out-of-line single-stepping".
3654 show debug displaced
3655 Control display of debugging info for displaced stepping.
3657 maint set internal-error
3658 maint show internal-error
3659 Control what GDB does when an internal error is detected.
3661 maint set internal-warning
3662 maint show internal-warning
3663 Control what GDB does when an internal warning is detected.
3668 Use a wrapper program to launch programs for debugging.
3670 set multiple-symbols (all|ask|cancel)
3671 show multiple-symbols
3672 The value of this variable can be changed to adjust the debugger behavior
3673 when an expression or a breakpoint location contains an ambiguous symbol
3674 name (an overloaded function name, for instance).
3676 set breakpoint always-inserted
3677 show breakpoint always-inserted
3678 Keep breakpoints always inserted in the target, as opposed to inserting
3679 them when resuming the target, and removing them when the target stops.
3680 This option can improve debugger performance on slow remote targets.
3682 set arm fallback-mode (arm|thumb|auto)
3683 show arm fallback-mode
3684 set arm force-mode (arm|thumb|auto)
3686 These commands control how ARM GDB determines whether instructions
3687 are ARM or Thumb. The default for both settings is auto, which uses
3688 the current CPSR value for instructions without symbols; previous
3689 versions of GDB behaved as if "set arm fallback-mode arm".
3691 set disable-randomization
3692 show disable-randomization
3693 Standalone programs run with the virtual address space randomization enabled
3694 by default on some platforms. This option keeps the addresses stable across
3695 multiple debugging sessions.
3699 Control whether other threads are stopped or not when some thread hits
3704 Requests that asynchronous execution is enabled in the target, if available.
3705 In this case, it's possible to resume target in the background, and interact
3706 with GDB while the target is running. "show target-async" displays the
3707 current state of asynchronous execution of the target.
3709 set target-wide-charset
3710 show target-wide-charset
3711 The target-wide-charset is the name of the character set that GDB
3712 uses when printing characters whose type is wchar_t.
3714 set tcp auto-retry (on|off)
3716 set tcp connect-timeout
3717 show tcp connect-timeout
3718 These commands allow GDB to retry failed TCP connections to a remote stub
3719 with a specified timeout period; this is useful if the stub is launched
3720 in parallel with GDB but may not be ready to accept connections immediately.
3722 set libthread-db-search-path
3723 show libthread-db-search-path
3724 Control list of directories which GDB will search for appropriate
3727 set schedule-multiple (on|off)
3728 show schedule-multiple
3729 Allow GDB to resume all threads of all processes or only threads of
3730 the current process.
3734 Use more aggressive caching for accesses to the stack. This improves
3735 performance of remote debugging (particularly backtraces) without
3736 affecting correctness.
3738 set interactive-mode (on|off|auto)
3739 show interactive-mode
3740 Control whether GDB runs in interactive mode (on) or not (off).
3741 When in interactive mode, GDB waits for the user to answer all
3742 queries. Otherwise, GDB does not wait and assumes the default
3743 answer. When set to auto (the default), GDB determines which
3744 mode to use based on the stdin settings.
3749 For program forks, this is replaced by the new more generic `info
3750 inferiors' command. To list checkpoints, you can still use the
3751 `info checkpoints' command, which was an alias for the `info forks'
3755 Replaced by the new `inferior' command. To switch between
3756 checkpoints, you can still use the `restart' command, which was an
3757 alias for the `fork' command.
3760 This is removed, since some targets don't have a notion of
3761 processes. To switch between processes, you can still use the
3762 `inferior' command using GDB's own inferior number.
3765 For program forks, this is replaced by the new more generic `kill
3766 inferior' command. To delete a checkpoint, you can still use the
3767 `delete checkpoint' command, which was an alias for the `delete
3771 For program forks, this is replaced by the new more generic `detach
3772 inferior' command. To detach a checkpoint, you can still use the
3773 `detach checkpoint' command, which was an alias for the `detach
3776 * New native configurations
3778 x86/x86_64 Darwin i[34567]86-*-darwin*
3780 x86_64 MinGW x86_64-*-mingw*
3784 Lattice Mico32 lm32-*
3785 x86 DICOS i[34567]86-*-dicos*
3786 x86_64 DICOS x86_64-*-dicos*
3789 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3790 (mingw32ce) debugging.
3796 These commands were actually not implemented on any target.
3798 *** Changes in GDB 6.8
3800 * New native configurations
3802 NetBSD/hppa hppa*-*netbsd*
3803 Xtensa GNU/Linux xtensa*-*-linux*
3807 NetBSD/hppa hppa*-*-netbsd*
3808 Xtensa GNU/Lunux xtensa*-*-linux*
3810 * Change in command line behavior -- corefiles vs. process ids.
3812 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3813 attaching to process NUMBER fails, GDB no longer attempts to open a
3814 core file named NUMBER. Attaching to a program using the -c option
3815 is no longer supported. Instead, use the '-p' or '--pid' options.
3817 * GDB can now be built as a native debugger for debugging Windows x86
3818 (mingw32) Portable Executable (PE) programs.
3820 * Pending breakpoints no longer change their number when their address
3823 * GDB now supports breakpoints with multiple locations,
3824 including breakpoints on C++ constructors, inside C++ templates,
3825 and in inlined functions.
3827 * GDB's ability to debug optimized code has been improved. GDB more
3828 accurately identifies function bodies and lexical blocks that occupy
3829 more than one contiguous range of addresses.
3831 * Target descriptions can now describe registers for PowerPC.
3833 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3834 registers on PowerPC targets.
3836 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3837 targets even when the libthread_db library is not available.
3839 * The GDB remote stub, gdbserver, now supports the new file transfer
3840 commands (remote put, remote get, and remote delete).
3842 * The GDB remote stub, gdbserver, now supports run and attach in
3843 extended-remote mode.
3845 * hppa*64*-*-hpux11* target broken
3846 The debugger is unable to start a program and fails with the following
3847 error: "Error trying to get information about dynamic linker".
3848 The gdb-6.7 release is also affected.
3850 * GDB now supports the --enable-targets= configure option to allow
3851 building a single GDB executable that supports multiple remote
3852 target architectures.
3854 * GDB now supports debugging C and C++ programs which use the
3855 Decimal Floating Point extension. In addition, the PowerPC target
3856 now has a set of pseudo-registers to inspect decimal float values
3857 stored in two consecutive float registers.
3859 * The -break-insert MI command can optionally create pending
3862 * Improved support for debugging Ada
3863 Many improvements to the Ada language support have been made. These
3865 - Better support for Ada2005 interface types
3866 - Improved handling of arrays and slices in general
3867 - Better support for Taft-amendment types
3868 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3870 - Improved command completion in Ada
3873 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3878 set print frame-arguments (all|scalars|none)
3879 show print frame-arguments
3880 The value of this variable can be changed to control which argument
3881 values should be printed by the debugger when displaying a frame.
3886 Transfer files to and from a remote target, and delete remote files.
3893 Transfer files to and from a remote target, and delete remote files.
3895 * New remote packets
3902 Open, close, read, write, and delete files on the remote system.
3905 Attach to an existing process on the remote system, in extended-remote
3909 Run a new process on the remote system, in extended-remote mode.
3911 *** Changes in GDB 6.7
3913 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3914 bfd, libiberty and opcodes, as revealed by static analysis donated by
3915 Coverity, Inc. (http://scan.coverity.com).
3917 * When looking up multiply-defined global symbols, GDB will now prefer the
3918 symbol definition in the current shared library if it was built using the
3919 -Bsymbolic linker option.
3921 * When the Text User Interface (TUI) is not configured, GDB will now
3922 recognize the -tui command-line option and print a message that the TUI
3925 * The GDB remote stub, gdbserver, now has lower overhead for high
3926 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3928 * GDB for MIPS targets now autodetects whether a remote target provides
3929 32-bit or 64-bit register values.
3931 * Support for C++ member pointers has been improved.
3933 * GDB now understands XML target descriptions, which specify the
3934 target's overall architecture. GDB can read a description from
3935 a local file or over the remote serial protocol.
3937 * Vectors of single-byte data use a new integer type which is not
3938 automatically displayed as character or string data.
3940 * The /s format now works with the print command. It displays
3941 arrays of single-byte integers and pointers to single-byte integers
3944 * Target descriptions can now describe target-specific registers,
3945 for architectures which have implemented the support (currently
3946 only ARM, M68K, and MIPS).
3948 * GDB and the GDB remote stub, gdbserver, now support the XScale
3951 * The GDB remote stub, gdbserver, has been updated to support
3952 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3953 has been rewritten to use the standard GDB remote protocol.
3955 * GDB can now step into C++ functions which are called through thunks.
3957 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3959 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3960 layout. It also supports a TextSeg= and DataSeg= response when only
3961 segment base addresses (rather than offsets) are available.
3963 * The /i format now outputs any trailing branch delay slot instructions
3964 immediately following the last instruction within the count specified.
3966 * The GDB remote protocol "T" stop reply packet now supports a
3967 "library" response. Combined with the new "qXfer:libraries:read"
3968 packet, this response allows GDB to debug shared libraries on targets
3969 where the operating system manages the list of loaded libraries (e.g.
3970 Windows and SymbianOS).
3972 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3973 (DLLs) on Windows and Windows CE targets.
3975 * GDB now supports a faster verification that a .debug file matches its binary
3976 according to its build-id signature, if the signature is present.
3982 Enable or disable hardware flow control (RTS/CTS) on the serial port
3983 when debugging using remote targets.
3985 set mem inaccessible-by-default
3986 show mem inaccessible-by-default
3987 If the target supplies a memory map, for instance via the remote
3988 protocol's "qXfer:memory-map:read" packet, setting this variable
3989 prevents GDB from accessing memory outside the memory map. This
3990 is useful for targets with memory mapped registers or which react
3991 badly to accesses of unmapped address space.
3993 set breakpoint auto-hw
3994 show breakpoint auto-hw
3995 If the target supplies a memory map, for instance via the remote
3996 protocol's "qXfer:memory-map:read" packet, setting this variable
3997 lets GDB use hardware breakpoints automatically for memory regions
3998 where it can not use software breakpoints. This covers both the
3999 "break" command and internal breakpoints used for other commands
4000 including "next" and "finish".
4003 catch exception unhandled
4004 Stop the program execution when Ada exceptions are raised.
4007 Stop the program execution when an Ada assertion failed.
4011 Set an alternate system root for target files. This is a more
4012 general version of "set solib-absolute-prefix", which is now
4013 an alias to "set sysroot".
4016 Provide extended SPU facility status information. This set of
4017 commands is available only when debugging the Cell/B.E. SPU
4020 * New native configurations
4022 OpenBSD/sh sh*-*openbsd*
4025 unset tdesc filename
4027 Use the specified local file as an XML target description, and do
4028 not query the target for its built-in description.
4032 OpenBSD/sh sh*-*-openbsd*
4033 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4034 Toshiba Media Processor mep-elf
4036 * New remote packets
4039 Ignore the specified signals; pass them directly to the debugged program
4040 without stopping other threads or reporting them to GDB.
4042 qXfer:features:read:
4043 Read an XML target description from the target, which describes its
4048 Read or write contents of an spufs file on the target system. These
4049 packets are available only on the Cell/B.E. SPU architecture.
4051 qXfer:libraries:read:
4052 Report the loaded shared libraries. Combined with new "T" packet
4053 response, this packet allows GDB to debug shared libraries on
4054 targets where the operating system manages the list of loaded
4055 libraries (e.g. Windows and SymbianOS).
4059 Support for these obsolete configurations has been removed.
4067 i[34567]86-*-lynxos*
4068 i[34567]86-*-netware*
4069 i[34567]86-*-sco3.2v5*
4070 i[34567]86-*-sco3.2v4*
4072 i[34567]86-*-sysv4.2*
4075 i[34567]86-*-unixware2*
4076 i[34567]86-*-unixware*
4085 * Other removed features
4092 Various m68k-only ROM monitors.
4099 Various Renesas ROM monitors and debugging interfaces for SH and
4104 Support for a Macraigor serial interface to on-chip debugging.
4105 GDB does not directly support the newer parallel or USB
4110 A debug information format. The predecessor to DWARF 2 and
4111 DWARF 3, which are still supported.
4113 Support for the HP aCC compiler on HP-UX/PA-RISC
4115 SOM-encapsulated symbolic debugging information, automatic
4116 invocation of pxdb, and the aCC custom C++ ABI. This does not
4117 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4118 with aCC can still be debugged on an assembly level.
4120 MIPS ".pdr" sections
4122 A MIPS-specific format used to describe stack frame layout
4123 in debugging information.
4127 GDB could work with an older version of Guile to debug
4128 the interpreter and Scheme programs running in it.
4130 set mips stack-arg-size
4131 set mips saved-gpreg-size
4133 Use "set mips abi" to control parameter passing for MIPS.
4135 *** Changes in GDB 6.6
4140 Cell Broadband Engine SPU spu-elf
4142 * GDB can now be configured as a cross-debugger targeting native Windows
4143 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4144 running on a Windows system over TCP/IP to debug Windows programs.
4146 * The GDB remote stub, gdbserver, has been updated to support Windows and
4147 Cygwin debugging. Both single-threaded and multi-threaded programs are
4150 * The "set trust-readonly-sections" command works again. This command was
4151 broken in GDB 6.3, 6.4, and 6.5.
4153 * The "load" command now supports writing to flash memory, if the remote
4154 stub provides the required support.
4156 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4157 longer requires symbolic debug information (e.g. DWARF-2).
4162 unset substitute-path
4163 show substitute-path
4164 Manage a list of substitution rules that GDB uses to rewrite the name
4165 of the directories where the sources are located. This can be useful
4166 for instance when the sources were moved to a different location
4167 between compilation and debugging.
4171 Print each CLI command as it is executed. Each command is prefixed with
4172 a number of `+' symbols representing the nesting depth.
4173 The source command now has a `-v' option to enable the same feature.
4177 The ARM Demon monitor support (RDP protocol, "target rdp").
4179 Kernel Object Display, an embedded debugging feature which only worked with
4180 an obsolete version of Cisco IOS.
4182 The 'set download-write-size' and 'show download-write-size' commands.
4184 * New remote packets
4187 Tell a stub about GDB client features, and request remote target features.
4188 The first feature implemented is PacketSize, which allows the target to
4189 specify the size of packets it can handle - to minimize the number of
4190 packets required and improve performance when connected to a remote
4194 Fetch an OS auxilliary vector from the remote stub. This packet is a
4195 more efficient replacement for qPart:auxv:read.
4197 qXfer:memory-map:read:
4198 Fetch a memory map from the remote stub, including information about
4199 RAM, ROM, and flash memory devices.
4204 Erase and program a flash memory device.
4206 * Removed remote packets
4209 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4210 used it, and only gdbserver implemented it.
4212 *** Changes in GDB 6.5
4216 Renesas M32C/M16C m32c-elf
4218 Morpho Technologies ms1 ms1-elf
4222 init-if-undefined Initialize a convenience variable, but
4223 only if it doesn't already have a value.
4225 The following commands are presently only implemented for native GNU/Linux:
4227 checkpoint Save a snapshot of the program state.
4229 restart <n> Return the program state to a
4230 previously saved state.
4232 info checkpoints List currently saved checkpoints.
4234 delete-checkpoint <n> Delete a previously saved checkpoint.
4236 set|show detach-on-fork Tell gdb whether to detach from a newly
4237 forked process, or to keep debugging it.
4239 info forks List forks of the user program that
4240 are available to be debugged.
4242 fork <n> Switch to debugging one of several
4243 forks of the user program that are
4244 available to be debugged.
4246 delete-fork <n> Delete a fork from the list of forks
4247 that are available to be debugged (and
4248 kill the forked process).
4250 detach-fork <n> Delete a fork from the list of forks
4251 that are available to be debugged (and
4252 allow the process to continue).
4256 Morpho Technologies ms2 ms1-elf
4258 * Improved Windows host support
4260 GDB now builds as a cross debugger hosted on i686-mingw32, including
4261 native console support, and remote communications using either
4262 network sockets or serial ports.
4264 * Improved Modula-2 language support
4266 GDB can now print most types in the Modula-2 syntax. This includes:
4267 basic types, set types, record types, enumerated types, range types,
4268 pointer types and ARRAY types. Procedure var parameters are correctly
4269 printed and hexadecimal addresses and character constants are also
4270 written in the Modula-2 syntax. Best results can be obtained by using
4271 GNU Modula-2 together with the -gdwarf-2 command line option.
4275 The ARM rdi-share module.
4277 The Netware NLM debug server.
4279 *** Changes in GDB 6.4
4281 * New native configurations
4283 OpenBSD/arm arm*-*-openbsd*
4284 OpenBSD/mips64 mips64-*-openbsd*
4288 Morpho Technologies ms1 ms1-elf
4290 * New command line options
4292 --batch-silent As for --batch, but totally silent.
4293 --return-child-result The debugger will exist with the same value
4294 the child (debugged) program exited with.
4295 --eval-command COMMAND, -ex COMMAND
4296 Execute a single GDB CLI command. This may be
4297 specified multiple times and in conjunction
4298 with the --command (-x) option.
4300 * Deprecated commands removed
4302 The following commands, that were deprecated in 2000, have been
4306 set|show arm disassembly-flavor set|show arm disassembler
4307 othernames set arm disassembler
4308 set|show remotedebug set|show debug remote
4309 set|show archdebug set|show debug arch
4310 set|show eventdebug set|show debug event
4313 * New BSD user-level threads support
4315 It is now possible to debug programs using the user-level threads
4316 library on OpenBSD and FreeBSD. Currently supported (target)
4319 FreeBSD/amd64 x86_64-*-freebsd*
4320 FreeBSD/i386 i386-*-freebsd*
4321 OpenBSD/i386 i386-*-openbsd*
4323 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4324 are not yet supported.
4326 * New support for Matsushita MN10300 w/sim added
4327 (Work in progress). mn10300-elf.
4329 * REMOVED configurations and files
4331 VxWorks and the XDR protocol *-*-vxworks
4332 Motorola MCORE mcore-*-*
4333 National Semiconductor NS32000 ns32k-*-*
4335 * New "set print array-indexes" command
4337 After turning this setting "on", GDB prints the index of each element
4338 when displaying arrays. The default is "off" to preserve the previous
4341 * VAX floating point support
4343 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4345 * User-defined command support
4347 In addition to using $arg0..$arg9 for argument passing, it is now possible
4348 to use $argc to determine now many arguments have been passed. See the
4349 section on user-defined commands in the user manual for more information.
4351 *** Changes in GDB 6.3:
4353 * New command line option
4355 GDB now accepts -l followed by a number to set the timeout for remote
4358 * GDB works with GCC -feliminate-dwarf2-dups
4360 GDB now supports a more compact representation of DWARF-2 debug
4361 information using DW_FORM_ref_addr references. These are produced
4362 by GCC with the option -feliminate-dwarf2-dups and also by some
4363 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4364 to use -feliminate-dwarf2-dups.
4366 * Internationalization
4368 When supported by the host system, GDB will be built with
4369 internationalization (libintl). The task of marking up the sources is
4370 continued, we're looking forward to our first translation.
4374 Initial support for debugging programs compiled with the GNAT
4375 implementation of the Ada programming language has been integrated
4376 into GDB. In this release, support is limited to expression evaluation.
4378 * New native configurations
4380 GNU/Linux/m32r m32r-*-linux-gnu
4384 GDB's remote protocol now includes support for the 'p' packet. This
4385 packet is used to fetch individual registers from a remote inferior.
4387 * END-OF-LIFE registers[] compatibility module
4389 GDB's internal register infrastructure has been completely rewritten.
4390 The new infrastructure making possible the implementation of key new
4391 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4394 GDB 6.3 will be the last release to include the the registers[]
4395 compatibility module that allowed out-of-date configurations to
4396 continue to work. This change directly impacts the following
4406 powerpc bdm protocol
4408 Unless there is activity to revive these configurations, they will be
4409 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4411 * OBSOLETE configurations and files
4413 Configurations that have been declared obsolete in this release have
4414 been commented out. Unless there is activity to revive these
4415 configurations, the next release of GDB will have their sources
4416 permanently REMOVED.
4425 *** Changes in GDB 6.2.1:
4427 * MIPS `break main; run' gave an heuristic-fence-post warning
4429 When attempting to run even a simple program, a warning about
4430 heuristic-fence-post being hit would be reported. This problem has
4433 * MIPS IRIX 'long double' crashed GDB
4435 When examining a long double variable, GDB would get a segmentation
4436 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4437 IRIX long double values).
4441 A bug in the VAX stack code was causing problems with the "next"
4442 command. This problem has been fixed.
4444 *** Changes in GDB 6.2:
4446 * Fix for ``many threads''
4448 On GNU/Linux systems that use the NPTL threads library, a program
4449 rapidly creating and deleting threads would confuse GDB leading to the
4452 ptrace: No such process.
4453 thread_db_get_info: cannot get thread info: generic error
4455 This problem has been fixed.
4457 * "-async" and "-noasync" options removed.
4459 Support for the broken "-noasync" option has been removed (it caused
4462 * New ``start'' command.
4464 This command runs the program until the begining of the main procedure.
4466 * New BSD Kernel Data Access Library (libkvm) interface
4468 Using ``target kvm'' it is now possible to debug kernel core dumps and
4469 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4470 platforms. Currently supported (native-only) configurations are:
4472 FreeBSD/amd64 x86_64-*-freebsd*
4473 FreeBSD/i386 i?86-*-freebsd*
4474 NetBSD/i386 i?86-*-netbsd*
4475 NetBSD/m68k m68*-*-netbsd*
4476 NetBSD/sparc sparc-*-netbsd*
4477 OpenBSD/amd64 x86_64-*-openbsd*
4478 OpenBSD/i386 i?86-*-openbsd*
4479 OpenBSD/m68k m68*-openbsd*
4480 OpenBSD/sparc sparc-*-openbsd*
4482 * Signal trampoline code overhauled
4484 Many generic problems with GDB's signal handling code have been fixed.
4485 These include: backtraces through non-contiguous stacks; recognition
4486 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4487 call; backtrace through a signal trampoline; step into and out of
4488 signal handlers; and single-stepping in the signal trampoline.
4490 Please note that kernel bugs are a limiting factor here. These
4491 features have been shown to work on an s390 GNU/Linux system that
4492 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4494 * Cygwin support for DWARF 2 added.
4496 * New native configurations
4498 GNU/Linux/hppa hppa*-*-linux*
4499 OpenBSD/hppa hppa*-*-openbsd*
4500 OpenBSD/m68k m68*-*-openbsd*
4501 OpenBSD/m88k m88*-*-openbsd*
4502 OpenBSD/powerpc powerpc-*-openbsd*
4503 NetBSD/vax vax-*-netbsd*
4504 OpenBSD/vax vax-*-openbsd*
4506 * END-OF-LIFE frame compatibility module
4508 GDB's internal frame infrastructure has been completely rewritten.
4509 The new infrastructure making it possible to support key new features
4510 including DWARF 2 Call Frame Information. To aid in the task of
4511 migrating old configurations to this new infrastructure, a
4512 compatibility module, that allowed old configurations to continue to
4513 work, was also included.
4515 GDB 6.2 will be the last release to include this frame compatibility
4516 module. This change directly impacts the following configurations:
4526 Unless there is activity to revive these configurations, they will be
4527 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4529 * REMOVED configurations and files
4531 Sun 3, running SunOS 3 m68*-*-sunos3*
4532 Sun 3, running SunOS 4 m68*-*-sunos4*
4533 Sun 2, running SunOS 3 m68000-*-sunos3*
4534 Sun 2, running SunOS 4 m68000-*-sunos4*
4535 Motorola 680x0 running LynxOS m68*-*-lynxos*
4536 AT&T 3b1/Unix pc m68*-att-*
4537 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4538 decstation mips-dec-* mips-little-*
4539 riscos mips-*-riscos* mips-*-sysv*
4540 sonymips mips-sony-*
4541 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4543 *** Changes in GDB 6.1.1:
4545 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4547 The TUI (Text-mode User Interface) is now built as part of a default
4548 GDB configuration. It is enabled by either selecting the TUI with the
4549 command line option "-i=tui" or by running the separate "gdbtui"
4550 program. For more information on the TUI, see the manual "Debugging
4553 * Pending breakpoint support (also included in GDB 6.1)
4555 Support has been added to allow you to specify breakpoints in shared
4556 libraries that have not yet been loaded. If a breakpoint location
4557 cannot be found, and the "breakpoint pending" option is set to auto,
4558 GDB queries you if you wish to make the breakpoint pending on a future
4559 shared-library load. If and when GDB resolves the breakpoint symbol,
4560 the pending breakpoint is removed as one or more regular breakpoints
4563 Pending breakpoints are very useful for GCJ Java debugging.
4565 * Fixed ISO-C build problems
4567 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4568 non ISO-C code that stopped them being built using a more strict ISO-C
4569 compiler (e.g., IBM's C compiler).
4571 * Fixed build problem on IRIX 5
4573 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4574 wasn't able to compile compile on an IRIX 5 system.
4576 * Added execute permission to gdb/gdbserver/configure
4578 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4579 permission. This bug would cause configure to fail on a number of
4580 systems (Solaris, IRIX). Ref: server/519.
4582 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4584 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4585 has been updated to use constant array sizes.
4587 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4589 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4590 its generated DWARF Call Frame Info. This encoding was causing GDB to
4591 panic, that panic has been fixed. Ref: gdb/1628.
4593 * Fixed a problem when examining parameters in shared library code.
4595 When examining parameters in optimized shared library code generated
4596 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4597 not available''. GDB now correctly displays the variable's value.
4599 *** Changes in GDB 6.1:
4601 * Removed --with-mmalloc
4603 Support for the mmalloc memory manager has been removed, as it
4604 conflicted with the internal gdb byte cache.
4606 * Changes in AMD64 configurations
4608 The AMD64 target now includes the %cs and %ss registers. As a result
4609 the AMD64 remote protocol has changed; this affects the floating-point
4610 and SSE registers. If you rely on those registers for your debugging,
4611 you should upgrade gdbserver on the remote side.
4613 * Revised SPARC target
4615 The SPARC target has been completely revised, incorporating the
4616 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4617 support for LynxOS and SunOS 4 has been dropped. Calling functions
4618 from within GDB on operating systems with a non-executable stack
4619 (Solaris, OpenBSD) now works.
4623 GDB has a new C++ demangler which does a better job on the mangled
4624 names generated by current versions of g++. It also runs faster, so
4625 with this and other changes gdb should now start faster on large C++
4628 * DWARF 2 Location Expressions
4630 GDB support for location expressions has been extended to support function
4631 arguments and frame bases. Older versions of GDB could crash when they
4634 * C++ nested types and namespaces
4636 GDB's support for nested types and namespaces in C++ has been
4637 improved, especially if you use the DWARF 2 debugging format. (This
4638 is the default for recent versions of GCC on most platforms.)
4639 Specifically, if you have a class "Inner" defined within a class or
4640 namespace "Outer", then GDB realizes that the class's name is
4641 "Outer::Inner", not simply "Inner". This should greatly reduce the
4642 frequency of complaints about not finding RTTI symbols. In addition,
4643 if you are stopped at inside of a function defined within a namespace,
4644 GDB modifies its name lookup accordingly.
4646 * New native configurations
4648 NetBSD/amd64 x86_64-*-netbsd*
4649 OpenBSD/amd64 x86_64-*-openbsd*
4650 OpenBSD/alpha alpha*-*-openbsd*
4651 OpenBSD/sparc sparc-*-openbsd*
4652 OpenBSD/sparc64 sparc64-*-openbsd*
4654 * New debugging protocols
4656 M32R with SDI protocol m32r-*-elf*
4658 * "set prompt-escape-char" command deleted.
4660 The command "set prompt-escape-char" has been deleted. This command,
4661 and its very obscure effet on GDB's prompt, was never documented,
4662 tested, nor mentioned in the NEWS file.
4664 * OBSOLETE configurations and files
4666 Configurations that have been declared obsolete in this release have
4667 been commented out. Unless there is activity to revive these
4668 configurations, the next release of GDB will have their sources
4669 permanently REMOVED.
4671 Sun 3, running SunOS 3 m68*-*-sunos3*
4672 Sun 3, running SunOS 4 m68*-*-sunos4*
4673 Sun 2, running SunOS 3 m68000-*-sunos3*
4674 Sun 2, running SunOS 4 m68000-*-sunos4*
4675 Motorola 680x0 running LynxOS m68*-*-lynxos*
4676 AT&T 3b1/Unix pc m68*-att-*
4677 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4678 decstation mips-dec-* mips-little-*
4679 riscos mips-*-riscos* mips-*-sysv*
4680 sonymips mips-sony-*
4681 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4683 * REMOVED configurations and files
4685 SGI Irix-4.x mips-sgi-irix4 or iris4
4686 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4687 Z8000 simulator z8k-zilog-none or z8ksim
4688 Matsushita MN10200 w/simulator mn10200-*-*
4689 H8/500 simulator h8500-hitachi-hms or h8500hms
4690 HP/PA running BSD hppa*-*-bsd*
4691 HP/PA running OSF/1 hppa*-*-osf*
4692 HP/PA Pro target hppa*-*-pro*
4693 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4694 386BSD i[3456]86-*-bsd*
4695 Sequent family i[3456]86-sequent-sysv4*
4696 i[3456]86-sequent-sysv*
4697 i[3456]86-sequent-bsd*
4698 SPARC running LynxOS sparc-*-lynxos*
4699 SPARC running SunOS 4 sparc-*-sunos4*
4700 Tsqware Sparclet sparclet-*-*
4701 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4703 *** Changes in GDB 6.0:
4707 Support for debugging the Objective-C programming language has been
4708 integrated into GDB.
4710 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4712 DWARF 2's Call Frame Information makes available compiler generated
4713 information that more exactly describes the program's run-time stack.
4714 By using this information, GDB is able to provide more robust stack
4717 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4718 have been updated to use a new backtrace mechanism which includes
4719 DWARF 2 CFI support.
4723 GDB's remote protocol has been extended to include support for hosted
4724 file I/O (where the remote target uses GDB's file system). See GDB's
4725 remote protocol documentation for details.
4727 * All targets using the new architecture framework.
4729 All of GDB's targets have been updated to use the new internal
4730 architecture framework. The way is now open for future GDB releases
4731 to include cross-architecture native debugging support (i386 on amd64,
4734 * GNU/Linux's Thread Local Storage (TLS)
4736 GDB now includes support for for the GNU/Linux implementation of
4737 per-thread variables.
4739 * GNU/Linux's Native POSIX Thread Library (NPTL)
4741 GDB's thread code has been updated to work with either the new
4742 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4744 * Separate debug info.
4746 GDB, in conjunction with BINUTILS, now supports a mechanism for
4747 automatically loading debug information from a separate file. Instead
4748 of shipping full debug and non-debug versions of system libraries,
4749 system integrators can now instead ship just the stripped libraries
4750 and optional debug files.
4752 * DWARF 2 Location Expressions
4754 DWARF 2 Location Expressions allow the compiler to more completely
4755 describe the location of variables (even in optimized code) to the
4758 GDB now includes preliminary support for location expressions (support
4759 for DW_OP_piece is still missing).
4763 A number of long standing bugs that caused GDB to die while starting a
4764 Java application have been fixed. GDB's Java support is now
4765 considered "useable".
4767 * GNU/Linux support for fork, vfork, and exec.
4769 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4770 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4773 * GDB supports logging output to a file
4775 There are two new commands, "set logging" and "show logging", which can be
4776 used to capture GDB's output to a file.
4778 * The meaning of "detach" has changed for gdbserver
4780 The "detach" command will now resume the application, as documented. To
4781 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4784 * d10v, m68hc11 `regs' command deprecated
4786 The `info registers' command has been updated so that it displays the
4787 registers using a format identical to the old `regs' command.
4791 A new command, "maint set profile on/off", has been added. This command can
4792 be used to enable or disable profiling while running GDB, to profile a
4793 session or a set of commands. In addition there is a new configure switch,
4794 "--enable-profiling", which will cause GDB to be compiled with profiling
4795 data, for more informative profiling results.
4797 * Default MI syntax changed to "mi2".
4799 The default MI (machine interface) syntax, enabled by the command line
4800 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4801 "mi1", can be enabled by specifying the option "-i=mi1".
4803 Support for the original "mi0" syntax (included in GDB 5.0) has been
4806 Fix for gdb/192: removed extraneous space when displaying frame level.
4807 Fix for gdb/672: update changelist is now output in mi list format.
4808 Fix for gdb/702: a -var-assign that updates the value now shows up
4809 in a subsequent -var-update.
4811 * New native configurations.
4813 FreeBSD/amd64 x86_64-*-freebsd*
4815 * Multi-arched targets.
4817 HP/PA HPUX11 hppa*-*-hpux*
4818 Renesas M32R/D w/simulator m32r-*-elf*
4820 * OBSOLETE configurations and files
4822 Configurations that have been declared obsolete in this release have
4823 been commented out. Unless there is activity to revive these
4824 configurations, the next release of GDB will have their sources
4825 permanently REMOVED.
4827 Z8000 simulator z8k-zilog-none or z8ksim
4828 Matsushita MN10200 w/simulator mn10200-*-*
4829 H8/500 simulator h8500-hitachi-hms or h8500hms
4830 HP/PA running BSD hppa*-*-bsd*
4831 HP/PA running OSF/1 hppa*-*-osf*
4832 HP/PA Pro target hppa*-*-pro*
4833 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4834 Sequent family i[3456]86-sequent-sysv4*
4835 i[3456]86-sequent-sysv*
4836 i[3456]86-sequent-bsd*
4837 Tsqware Sparclet sparclet-*-*
4838 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4840 * REMOVED configurations and files
4843 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4844 IBM AIX PS/2 i[3456]86-*-aix
4845 i386 running Mach 3.0 i[3456]86-*-mach3*
4846 i386 running Mach i[3456]86-*-mach*
4847 i386 running OSF/1 i[3456]86-*osf1mk*
4848 HP/Apollo 68k Family m68*-apollo*-sysv*,
4850 m68*-hp-bsd*, m68*-hp-hpux*
4851 Argonaut Risc Chip (ARC) arc-*-*
4852 Mitsubishi D30V d30v-*-*
4853 Fujitsu FR30 fr30-*-elf*
4854 OS/9000 i[34]86-*-os9k
4855 I960 with MON960 i960-*-coff
4857 * MIPS $fp behavior changed
4859 The convenience variable $fp, for the MIPS, now consistently returns
4860 the address of the current frame's base. Previously, depending on the
4861 context, $fp could refer to either $sp or the current frame's base
4862 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4863 The GNU Source-Level Debugger''.
4865 *** Changes in GDB 5.3:
4867 * GNU/Linux shared library multi-threaded performance improved.
4869 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4870 `/proc', in preference to `ptrace' for memory reads. This may result
4871 in an improvement in the start-up time of multi-threaded, shared
4872 library applications when run under GDB. One GDB user writes: ``loads
4873 shared libs like mad''.
4875 * ``gdbserver'' now supports multi-threaded applications on some targets
4877 Support for debugging multi-threaded applications which use
4878 the GNU/Linux LinuxThreads package has been added for
4879 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4880 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4882 * GDB now supports C/C++ preprocessor macros.
4884 GDB now expands preprocessor macro invocations in C/C++ expressions,
4885 and provides various commands for showing macro definitions and how
4888 The new command `macro expand EXPRESSION' expands any macro
4889 invocations in expression, and shows the result.
4891 The new command `show macro MACRO-NAME' shows the definition of the
4892 macro named MACRO-NAME, and where it was defined.
4894 Most compilers don't include information about macros in the debugging
4895 information by default. In GCC 3.1, for example, you need to compile
4896 your program with the options `-gdwarf-2 -g3'. If the macro
4897 information is present in the executable, GDB will read it.
4899 * Multi-arched targets.
4901 DEC Alpha (partial) alpha*-*-*
4902 DEC VAX (partial) vax-*-*
4904 National Semiconductor NS32000 (partial) ns32k-*-*
4905 Motorola 68000 (partial) m68k-*-*
4906 Motorola MCORE mcore-*-*
4910 Fujitsu FRV architecture added by Red Hat frv*-*-*
4913 * New native configurations
4915 Alpha NetBSD alpha*-*-netbsd*
4916 SH NetBSD sh*-*-netbsdelf*
4917 MIPS NetBSD mips*-*-netbsd*
4918 UltraSPARC NetBSD sparc64-*-netbsd*
4920 * OBSOLETE configurations and files
4922 Configurations that have been declared obsolete in this release have
4923 been commented out. Unless there is activity to revive these
4924 configurations, the next release of GDB will have their sources
4925 permanently REMOVED.
4927 Mitsubishi D30V d30v-*-*
4928 OS/9000 i[34]86-*-os9k
4929 IBM AIX PS/2 i[3456]86-*-aix
4930 Fujitsu FR30 fr30-*-elf*
4931 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4932 Argonaut Risc Chip (ARC) arc-*-*
4933 i386 running Mach 3.0 i[3456]86-*-mach3*
4934 i386 running Mach i[3456]86-*-mach*
4935 i386 running OSF/1 i[3456]86-*osf1mk*
4936 HP/Apollo 68k Family m68*-apollo*-sysv*,
4938 m68*-hp-bsd*, m68*-hp-hpux*
4939 I960 with MON960 i960-*-coff
4941 * OBSOLETE languages
4943 CHILL, a Pascal like language used by telecommunications companies.
4945 * REMOVED configurations and files
4947 AMD 29k family via UDI a29k-amd-udi, udi29k
4948 A29K VxWorks a29k-*-vxworks
4949 AMD 29000 embedded, using EBMON a29k-none-none
4950 AMD 29000 embedded with COFF a29k-none-coff
4951 AMD 29000 embedded with a.out a29k-none-aout
4953 testsuite/gdb.hp/gdb.threads-hp/ directory
4955 * New command "set max-user-call-depth <nnn>"
4957 This command allows the user to limit the call depth of user-defined
4958 commands. The default is 1024.
4960 * Changes in FreeBSD/i386 native debugging.
4962 Support for the "generate-core-file" has been added.
4964 * New commands "dump", "append", and "restore".
4966 These commands allow data to be copied from target memory
4967 to a bfd-format or binary file (dump and append), and back
4968 from a file into memory (restore).
4970 * Improved "next/step" support on multi-processor Alpha Tru64.
4972 The previous single-step mechanism could cause unpredictable problems,
4973 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4974 of a software single-step mechanism prevents this.
4976 *** Changes in GDB 5.2.1:
4984 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4985 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4986 Fix, by Joel Brobecker imported from mainline.
4988 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4989 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4990 Fix, by Fred Fish, imported from mainline.
4992 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4993 Surprisingly enough, it works now.
4994 By Michal Ludvig, imported from mainline.
4996 i386 hardware watchpoint support:
4997 avoid misses on second run for some targets.
4998 By Pierre Muller, imported from mainline.
5000 *** Changes in GDB 5.2:
5002 * New command "set trust-readonly-sections on[off]".
5004 This command is a hint that tells gdb that read-only sections
5005 really are read-only (ie. that their contents will not change).
5006 In this mode, gdb will go to the object file rather than the
5007 target to read memory from read-only sections (such as ".text").
5008 This can be a significant performance improvement on some
5009 (notably embedded) targets.
5011 * New command "generate-core-file" (or "gcore").
5013 This new gdb command allows the user to drop a core file of the child
5014 process state at any time. So far it's been implemented only for
5015 GNU/Linux and Solaris, but should be relatively easily ported to other
5016 hosts. Argument is core file name (defaults to core.<pid>).
5018 * New command line option
5020 GDB now accepts --pid or -p followed by a process id.
5022 * Change in command line behavior -- corefiles vs. process ids.
5024 There is a subtle behavior in the way in which GDB handles
5025 command line arguments. The first non-flag argument is always
5026 a program to debug, but the second non-flag argument may either
5027 be a corefile or a process id. Previously, GDB would attempt to
5028 open the second argument as a corefile, and if that failed, would
5029 issue a superfluous error message and then attempt to attach it as
5030 a process. Now, if the second argument begins with a non-digit,
5031 it will be treated as a corefile. If it begins with a digit,
5032 GDB will attempt to attach it as a process, and if no such process
5033 is found, will then attempt to open it as a corefile.
5035 * Changes in ARM configurations.
5037 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5038 configuration is fully multi-arch.
5040 * New native configurations
5042 ARM NetBSD arm*-*-netbsd*
5043 x86 OpenBSD i[3456]86-*-openbsd*
5044 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5045 Sparc64 running FreeBSD sparc64-*-freebsd*
5049 Sanyo XStormy16 xstormy16-elf
5051 * OBSOLETE configurations and files
5053 Configurations that have been declared obsolete in this release have
5054 been commented out. Unless there is activity to revive these
5055 configurations, the next release of GDB will have their sources
5056 permanently REMOVED.
5058 AMD 29k family via UDI a29k-amd-udi, udi29k
5059 A29K VxWorks a29k-*-vxworks
5060 AMD 29000 embedded, using EBMON a29k-none-none
5061 AMD 29000 embedded with COFF a29k-none-coff
5062 AMD 29000 embedded with a.out a29k-none-aout
5064 testsuite/gdb.hp/gdb.threads-hp/ directory
5066 * REMOVED configurations and files
5068 TI TMS320C80 tic80-*-*
5070 PowerPC Solaris powerpcle-*-solaris*
5071 PowerPC Windows NT powerpcle-*-cygwin32
5072 PowerPC Netware powerpc-*-netware*
5073 Harris/CXUX m88k m88*-harris-cxux*
5074 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5075 ns32k-utek-sysv* ns32k-utek-*
5076 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5077 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5078 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5079 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5080 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5082 * Changes to command line processing
5084 The new `--args' feature can be used to specify command-line arguments
5085 for the inferior from gdb's command line.
5087 * Changes to key bindings
5089 There is a new `operate-and-get-next' function bound to `C-o'.
5091 *** Changes in GDB 5.1.1
5093 Fix compile problem on DJGPP.
5095 Fix a problem with floating-point registers on the i386 being
5098 Fix to stop GDB crashing on .debug_str debug info.
5100 Numerous documentation fixes.
5102 Numerous testsuite fixes.
5104 *** Changes in GDB 5.1:
5106 * New native configurations
5108 Alpha FreeBSD alpha*-*-freebsd*
5109 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5110 MIPS GNU/Linux mips*-*-linux*
5111 MIPS SGI Irix 6.x mips*-sgi-irix6*
5112 ia64 AIX ia64-*-aix*
5113 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5117 Motorola 68HC11 and 68HC12 m68hc11-elf
5119 UltraSparc running GNU/Linux sparc64-*-linux*
5121 * OBSOLETE configurations and files
5123 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5124 Harris/CXUX m88k m88*-harris-cxux*
5125 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5126 ns32k-utek-sysv* ns32k-utek-*
5127 TI TMS320C80 tic80-*-*
5129 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5130 PowerPC Solaris powerpcle-*-solaris*
5131 PowerPC Windows NT powerpcle-*-cygwin32
5132 PowerPC Netware powerpc-*-netware*
5133 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5134 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5135 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5136 Apple Macintosh (MPW) host N/A
5138 stuff.c (Program to stuff files into a specially prepared space in kdb)
5139 kdb-start.c (Main loop for the standalone kernel debugger)
5141 Configurations that have been declared obsolete in this release have
5142 been commented out. Unless there is activity to revive these
5143 configurations, the next release of GDB will have their sources
5144 permanently REMOVED.
5146 * REMOVED configurations and files
5148 Altos 3068 m68*-altos-*
5149 Convex c1-*-*, c2-*-*
5151 ARM RISCix arm-*-* (as host)
5155 * GDB has been converted to ISO C.
5157 GDB's source code has been converted to ISO C. In particular, the
5158 sources are fully protoized, and rely on standard headers being
5163 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5165 * The MI enabled by default.
5167 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5168 revised and enabled by default. Packages which use GDB as a debugging
5169 engine behind a UI or another front end are encouraged to switch to
5170 using the GDB/MI interface, instead of the old annotations interface
5171 which is now deprecated.
5173 * Support for debugging Pascal programs.
5175 GDB now includes support for debugging Pascal programs. The following
5176 main features are supported:
5178 - Pascal-specific data types such as sets;
5180 - automatic recognition of Pascal sources based on file-name
5183 - Pascal-style display of data types, variables, and functions;
5185 - a Pascal expression parser.
5187 However, some important features are not yet supported.
5189 - Pascal string operations are not supported at all;
5191 - there are some problems with boolean types;
5193 - Pascal type hexadecimal constants are not supported
5194 because they conflict with the internal variables format;
5196 - support for Pascal objects and classes is not full yet;
5198 - unlike Pascal, GDB is case-sensitive for symbol names.
5200 * Changes in completion.
5202 Commands such as `shell', `run' and `set args', which pass arguments
5203 to inferior programs, now complete on file names, similar to what
5204 users expect at the shell prompt.
5206 Commands which accept locations, such as `disassemble', `print',
5207 `breakpoint', `until', etc. now complete on filenames as well as
5208 program symbols. Thus, if you type "break foob TAB", and the source
5209 files linked into the programs include `foobar.c', that file name will
5210 be one of the candidates for completion. However, file names are not
5211 considered for completion after you typed a colon that delimits a file
5212 name from a name of a function in that file, as in "break foo.c:bar".
5214 `set demangle-style' completes on available demangling styles.
5216 * New platform-independent commands:
5218 It is now possible to define a post-hook for a command as well as a
5219 hook that runs before the command. For more details, see the
5220 documentation of `hookpost' in the GDB manual.
5222 * Changes in GNU/Linux native debugging.
5224 Support for debugging multi-threaded programs has been completely
5225 revised for all platforms except m68k and sparc. You can now debug as
5226 many threads as your system allows you to have.
5228 Attach/detach is supported for multi-threaded programs.
5230 Support for SSE registers was added for x86. This doesn't work for
5231 multi-threaded programs though.
5233 * Changes in MIPS configurations.
5235 Multi-arch support is enabled for all MIPS configurations.
5237 GDB can now be built as native debugger on SGI Irix 6.x systems for
5238 debugging n32 executables. (Debugging 64-bit executables is not yet
5241 * Unified support for hardware watchpoints in all x86 configurations.
5243 Most (if not all) native x86 configurations support hardware-assisted
5244 breakpoints and watchpoints in a unified manner. This support
5245 implements debug register sharing between watchpoints, which allows to
5246 put a virtually infinite number of watchpoints on the same address,
5247 and also supports watching regions up to 16 bytes with several debug
5250 The new maintenance command `maintenance show-debug-regs' toggles
5251 debugging print-outs in functions that insert, remove, and test
5252 watchpoints and hardware breakpoints.
5254 * Changes in the DJGPP native configuration.
5256 New command ``info dos sysinfo'' displays assorted information about
5257 the CPU, OS, memory, and DPMI server.
5259 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5260 display information about segment descriptors stored in GDT, LDT, and
5263 New commands ``info dos pde'' and ``info dos pte'' display entries
5264 from Page Directory and Page Tables (for now works with CWSDPMI only).
5265 New command ``info dos address-pte'' displays the Page Table entry for
5266 a given linear address.
5268 GDB can now pass command lines longer than 126 characters to the
5269 program being debugged (requires an update to the libdbg.a library
5270 which is part of the DJGPP development kit).
5272 DWARF2 debug info is now supported.
5274 It is now possible to `step' and `next' through calls to `longjmp'.
5276 * Changes in documentation.
5278 All GDB documentation was converted to GFDL, the GNU Free
5279 Documentation License.
5281 Tracepoints-related commands are now fully documented in the GDB
5284 TUI, the Text-mode User Interface, is now documented in the manual.
5286 Tracepoints-related commands are now fully documented in the GDB
5289 The "GDB Internals" manual now has an index. It also includes
5290 documentation of `ui_out' functions, GDB coding standards, x86
5291 hardware watchpoints, and memory region attributes.
5293 * GDB's version number moved to ``version.in''
5295 The Makefile variable VERSION has been replaced by the file
5296 ``version.in''. People creating GDB distributions should update the
5297 contents of this file.
5301 GUD support is now a standard part of the EMACS distribution.
5303 *** Changes in GDB 5.0:
5305 * Improved support for debugging FP programs on x86 targets
5307 Unified and much-improved support for debugging floating-point
5308 programs on all x86 targets. In particular, ``info float'' now
5309 displays the FP registers in the same format on all x86 targets, with
5310 greater level of detail.
5312 * Improvements and bugfixes in hardware-assisted watchpoints
5314 It is now possible to watch array elements, struct members, and
5315 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5316 on x86 targets no longer erroneously trigger when the address is
5319 * Improvements in the native DJGPP version of GDB
5321 The distribution now includes all the scripts and auxiliary files
5322 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5323 machines ``out of the box''.
5325 The DJGPP version can now debug programs that use signals. It is
5326 possible to catch signals that happened in the debuggee, deliver
5327 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5328 would kill the program being debugged.) Programs that hook hardware
5329 interrupts (keyboard, timer, etc.) can also be debugged.
5331 It is now possible to debug DJGPP programs that redirect their
5332 standard handles or switch them to raw (as opposed to cooked) mode, or
5333 even close them. The command ``run < foo > bar'' works as expected,
5334 and ``info terminal'' reports useful information about the debuggee's
5335 terminal, including raw/cooked mode, redirection, etc.
5337 The DJGPP version now uses termios functions for console I/O, which
5338 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5341 DOS-style file names with drive letters are now fully supported by
5344 It is now possible to debug DJGPP programs that switch their working
5345 directory. It is also possible to rerun the debuggee any number of
5346 times without restarting GDB; thus, you can use the same setup,
5347 breakpoints, etc. for many debugging sessions.
5349 * New native configurations
5351 ARM GNU/Linux arm*-*-linux*
5352 PowerPC GNU/Linux powerpc-*-linux*
5356 Motorola MCore mcore-*-*
5357 x86 VxWorks i[3456]86-*-vxworks*
5358 PowerPC VxWorks powerpc-*-vxworks*
5359 TI TMS320C80 tic80-*-*
5361 * OBSOLETE configurations
5363 Altos 3068 m68*-altos-*
5364 Convex c1-*-*, c2-*-*
5366 ARM RISCix arm-*-* (as host)
5369 Configurations that have been declared obsolete will be commented out,
5370 but the code will be left in place. If there is no activity to revive
5371 these configurations before the next release of GDB, the sources will
5372 be permanently REMOVED.
5374 * Gould support removed
5376 Support for the Gould PowerNode and NP1 has been removed.
5378 * New features for SVR4
5380 On SVR4 native platforms (such as Solaris), if you attach to a process
5381 without first loading a symbol file, GDB will now attempt to locate and
5382 load symbols from the running process's executable file.
5384 * Many C++ enhancements
5386 C++ support has been greatly improved. Overload resolution now works properly
5387 in almost all cases. RTTI support is on the way.
5389 * Remote targets can connect to a sub-program
5391 A popen(3) style serial-device has been added. This device starts a
5392 sub-process (such as a stand-alone simulator) and then communicates
5393 with that. The sub-program to run is specified using the syntax
5394 ``|<program> <args>'' vis:
5396 (gdb) set remotedebug 1
5397 (gdb) target extended-remote |mn10300-elf-sim program-args
5399 * MIPS 64 remote protocol
5401 A long standing bug in the mips64 remote protocol where by GDB
5402 expected certain 32 bit registers (ex SR) to be transfered as 32
5403 instead of 64 bits has been fixed.
5405 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5406 added to provide backward compatibility with older versions of GDB.
5408 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5410 The command ``set remotebinarydownload'' command has been replaced by
5411 ``set remote X-packet''. Other commands in ``set remote'' family
5412 include ``set remote P-packet''.
5414 * Breakpoint commands accept ranges.
5416 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5417 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5418 ``tracepoint passcount'' also accepts a range of tracepoints.
5420 * ``apropos'' command added.
5422 The ``apropos'' command searches through command names and
5423 documentation strings, printing out matches, making it much easier to
5424 try to find a command that does what you are looking for.
5428 A new machine oriented interface (MI) has been added to GDB. This
5429 interface is designed for debug environments running GDB as a separate
5430 process. This is part of the long term libGDB project. See the
5431 "GDB/MI" chapter of the GDB manual for further information. It can be
5432 enabled by configuring with:
5434 .../configure --enable-gdbmi
5436 *** Changes in GDB-4.18:
5438 * New native configurations
5440 HP-UX 10.20 hppa*-*-hpux10.20
5441 HP-UX 11.x hppa*-*-hpux11.0*
5442 M68K GNU/Linux m68*-*-linux*
5446 Fujitsu FR30 fr30-*-elf*
5447 Intel StrongARM strongarm-*-*
5448 Mitsubishi D30V d30v-*-*
5450 * OBSOLETE configurations
5452 Gould PowerNode, NP1 np1-*-*, pn-*-*
5454 Configurations that have been declared obsolete will be commented out,
5455 but the code will be left in place. If there is no activity to revive
5456 these configurations before the next release of GDB, the sources will
5457 be permanently REMOVED.
5461 As a compatibility experiment, GDB's source files buildsym.h and
5462 buildsym.c have been converted to pure standard C, no longer
5463 containing any K&R compatibility code. We believe that all systems in
5464 use today either come with a standard C compiler, or have a GCC port
5465 available. If this is not true, please report the affected
5466 configuration to bug-gdb@gnu.org immediately. See the README file for
5467 information about getting a standard C compiler if you don't have one
5472 GDB now uses readline 2.2.
5474 * set extension-language
5476 You can now control the mapping between filename extensions and source
5477 languages by using the `set extension-language' command. For instance,
5478 you can ask GDB to treat .c files as C++ by saying
5479 set extension-language .c c++
5480 The command `info extensions' lists all of the recognized extensions
5481 and their associated languages.
5483 * Setting processor type for PowerPC and RS/6000
5485 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5486 you can use the `set processor' command to specify what variant of the
5487 PowerPC family you are debugging. The command
5491 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5492 following PowerPC and RS6000 variants:
5494 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5495 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5497 403GC IBM PowerPC 403GC
5498 505 Motorola PowerPC 505
5499 860 Motorola PowerPC 860 or 850
5500 601 Motorola PowerPC 601
5501 602 Motorola PowerPC 602
5502 603 Motorola/IBM PowerPC 603 or 603e
5503 604 Motorola PowerPC 604 or 604e
5504 750 Motorola/IBM PowerPC 750 or 750
5506 At the moment, this command just tells GDB what to name the
5507 special-purpose processor registers. Since almost all the affected
5508 registers are inaccessible to user-level programs, this command is
5509 only useful for remote debugging in its present form.
5513 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5514 more extensive support for HP-UX. Added features include shared
5515 library support, kernel threads and hardware watchpoints for 11.00,
5516 support for HP's ANSI C and C++ compilers, and a compatibility mode
5517 for xdb and dbx commands.
5521 HP's donation includes the new concept of catchpoints, which is a
5522 generalization of the old catch command. On HP-UX, it is now possible
5523 to catch exec, fork, and vfork, as well as library loading.
5525 This means that the existing catch command has changed; its first
5526 argument now specifies the type of catch to be set up. See the
5527 output of "help catch" for a list of catchpoint types.
5529 * Debugging across forks
5531 On HP-UX, you can choose which process to debug when a fork() happens
5536 HP has donated a curses-based terminal user interface (TUI). To get
5537 it, build with --enable-tui. Although this can be enabled for any
5538 configuration, at present it only works for native HP debugging.
5540 * GDB remote protocol additions
5542 A new protocol packet 'X' that writes binary data is now available.
5543 Default behavior is to try 'X', then drop back to 'M' if the stub
5544 fails to respond. The settable variable `remotebinarydownload'
5545 allows explicit control over the use of 'X'.
5547 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5548 full 64-bit address. The command
5550 set remoteaddresssize 32
5552 can be used to revert to the old behaviour. For existing remote stubs
5553 the change should not be noticed, as the additional address information
5556 In order to assist in debugging stubs, you may use the maintenance
5557 command `packet' to send any text string to the stub. For instance,
5559 maint packet heythere
5561 sends the packet "$heythere#<checksum>". Note that it is very easy to
5562 disrupt a debugging session by sending the wrong packet at the wrong
5565 The compare-sections command allows you to compare section data on the
5566 target to what is in the executable file without uploading or
5567 downloading, by comparing CRC checksums.
5569 * Tracing can collect general expressions
5571 You may now collect general expressions at tracepoints. This requires
5572 further additions to the target-side stub; see tracepoint.c and
5573 doc/agentexpr.texi for further details.
5575 * mask-address variable for Mips
5577 For Mips targets, you may control the zeroing of the upper 32 bits of
5578 a 64-bit address by entering `set mask-address on'. This is mainly
5579 of interest to users of embedded R4xxx and R5xxx processors.
5581 * Higher serial baud rates
5583 GDB's serial code now allows you to specify baud rates 57600, 115200,
5584 230400, and 460800 baud. (Note that your host system may not be able
5585 to achieve all of these rates.)
5589 The i960 configuration now includes an initial implementation of a
5590 builtin simulator, contributed by Jim Wilson.
5593 *** Changes in GDB-4.17:
5595 * New native configurations
5597 Alpha GNU/Linux alpha*-*-linux*
5598 Unixware 2.x i[3456]86-unixware2*
5599 Irix 6.x mips*-sgi-irix6*
5600 PowerPC GNU/Linux powerpc-*-linux*
5601 PowerPC Solaris powerpcle-*-solaris*
5602 Sparc GNU/Linux sparc-*-linux*
5603 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5607 Argonaut Risc Chip (ARC) arc-*-*
5608 Hitachi H8/300S h8300*-*-*
5609 Matsushita MN10200 w/simulator mn10200-*-*
5610 Matsushita MN10300 w/simulator mn10300-*-*
5611 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5612 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5613 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5614 Mitsubishi D10V w/simulator d10v-*-*
5615 Mitsubishi M32R/D w/simulator m32r-*-elf*
5616 Tsqware Sparclet sparclet-*-*
5617 NEC V850 w/simulator v850-*-*
5619 * New debugging protocols
5621 ARM with RDI protocol arm*-*-*
5622 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5623 DDB and LSI variants of PMON protocol mips*-*-*
5624 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5625 PowerPC with SDS protocol powerpc{,le}-*-eabi
5626 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5630 All configurations can now understand and use the DWARF 2 debugging
5631 format. The choice is automatic, if the symbol file contains DWARF 2
5636 GDB now includes basic Java language support. This support is
5637 only useful with Java compilers that produce native machine code.
5639 * solib-absolute-prefix and solib-search-path
5641 For SunOS and SVR4 shared libraries, you may now set the prefix for
5642 loading absolute shared library symbol files, and the search path for
5643 locating non-absolute shared library symbol files.
5645 * Live range splitting
5647 GDB can now effectively debug code for which GCC has performed live
5648 range splitting as part of its optimization. See gdb/doc/LRS for
5649 more details on the expected format of the stabs information.
5653 GDB's support for the GNU Hurd, including thread debugging, has been
5654 updated to work with current versions of the Hurd.
5658 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5659 instruction set. ARM GDB automatically detects when Thumb
5660 instructions are in use, and adjusts disassembly and backtracing
5665 GDB's MIPS target configurations now handle the MIP16 16-bit
5670 GDB now includes support for overlays; if an executable has been
5671 linked such that multiple sections are based at the same address, GDB
5672 will decide which section to use for symbolic info. You can choose to
5673 control the decision manually, using overlay commands, or implement
5674 additional target-side support and use "overlay load-target" to bring
5675 in the overlay mapping. Do "help overlay" for more detail.
5679 The command "info symbol <address>" displays information about
5680 the symbol at the specified address.
5684 The standard remote protocol now includes an extension that allows
5685 asynchronous collection and display of trace data. This requires
5686 extensive support in the target-side debugging stub. Tracing mode
5687 includes a new interaction mode in GDB and new commands: see the
5688 file tracepoint.c for more details.
5692 Configurations for embedded MIPS now include a simulator contributed
5693 by Cygnus Solutions. The simulator supports the instruction sets
5694 of most MIPS variants.
5698 Sparc configurations may now include the ERC32 simulator contributed
5699 by the European Space Agency. The simulator is not built into
5700 Sparc targets by default; configure with --enable-sim to include it.
5704 For target configurations that may include multiple variants of a
5705 basic architecture (such as MIPS and SH), you may now set the
5706 architecture explicitly. "set arch" sets, "info arch" lists
5707 the possible architectures.
5709 *** Changes in GDB-4.16:
5711 * New native configurations
5713 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5714 M68K NetBSD m68k-*-netbsd*
5715 PowerPC AIX 4.x powerpc-*-aix*
5716 PowerPC MacOS powerpc-*-macos*
5717 PowerPC Windows NT powerpcle-*-cygwin32
5718 RS/6000 AIX 4.x rs6000-*-aix4*
5722 ARM with RDP protocol arm-*-*
5723 I960 with MON960 i960-*-coff
5724 MIPS VxWorks mips*-*-vxworks*
5725 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5726 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5728 Matra Sparclet sparclet-*-*
5732 The powerpc-eabi configuration now includes the PSIM simulator,
5733 contributed by Andrew Cagney, with assistance from Mike Meissner.
5734 PSIM is a very elaborate model of the PowerPC, including not only
5735 basic instruction set execution, but also details of execution unit
5736 performance and I/O hardware. See sim/ppc/README for more details.
5740 GDB now works with Solaris 2.5.
5742 * Windows 95/NT native
5744 GDB will now work as a native debugger on Windows 95 and Windows NT.
5745 To build it from source, you must use the "gnu-win32" environment,
5746 which uses a DLL to emulate enough of Unix to run the GNU tools.
5747 Further information, binaries, and sources are available at
5748 ftp.cygnus.com, under pub/gnu-win32.
5750 * dont-repeat command
5752 If a user-defined command includes the command `dont-repeat', then the
5753 command will not be repeated if the user just types return. This is
5754 useful if the command is time-consuming to run, so that accidental
5755 extra keystrokes don't run the same command many times.
5757 * Send break instead of ^C
5759 The standard remote protocol now includes an option to send a break
5760 rather than a ^C to the target in order to interrupt it. By default,
5761 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5763 * Remote protocol timeout
5765 The standard remote protocol includes a new variable `remotetimeout'
5766 that allows you to set the number of seconds before GDB gives up trying
5767 to read from the target. The default value is 2.
5769 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5771 By default GDB will automatically keep track of objects as they are
5772 loaded and unloaded by the dynamic linker. By using the command `set
5773 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5774 when shared library events occur, thus allowing you to set breakpoints
5775 in shared libraries which are explicitly loaded by the inferior.
5777 Note this feature does not work on hpux8. On hpux9 you must link
5778 /usr/lib/end.o into your program. This feature should work
5779 automatically on hpux10.
5781 * Irix 5.x hardware watchpoint support
5783 Irix 5 configurations now support the use of hardware watchpoints.
5785 * Mips protocol "SYN garbage limit"
5787 When debugging a Mips target using the `target mips' protocol, you
5788 may set the number of characters that GDB will ignore by setting
5789 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5790 every character. The default value is 1050.
5792 * Recording and replaying remote debug sessions
5794 If you set `remotelogfile' to the name of a file, gdb will write to it
5795 a recording of a remote debug session. This recording may then be
5796 replayed back to gdb using "gdbreplay". See gdbserver/README for
5797 details. This is useful when you have a problem with GDB while doing
5798 remote debugging; you can make a recording of the session and send it
5799 to someone else, who can then recreate the problem.
5801 * Speedups for remote debugging
5803 GDB includes speedups for downloading and stepping MIPS systems using
5804 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5805 and more efficient S-record downloading.
5807 * Memory use reductions and statistics collection
5809 GDB now uses less memory and reports statistics about memory usage.
5810 Try the `maint print statistics' command, for example.
5812 *** Changes in GDB-4.15:
5814 * Psymtabs for XCOFF
5816 The symbol reader for AIX GDB now uses partial symbol tables. This
5817 can greatly improve startup time, especially for large executables.
5819 * Remote targets use caching
5821 Remote targets now use a data cache to speed up communication with the
5822 remote side. The data cache could lead to incorrect results because
5823 it doesn't know about volatile variables, thus making it impossible to
5824 debug targets which use memory mapped I/O devices. `set remotecache
5825 off' turns the the data cache off.
5827 * Remote targets may have threads
5829 The standard remote protocol now includes support for multiple threads
5830 in the target system, using new protocol commands 'H' and 'T'. See
5831 gdb/remote.c for details.
5835 If GDB is configured with `--enable-netrom', then it will include
5836 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5837 acts as though it is a bank of ROM on the target board, but you can
5838 write into it over the network. GDB's support consists only of
5839 support for fast loading into the emulated ROM; to debug, you must use
5840 another protocol, such as standard remote protocol. The usual
5841 sequence is something like
5843 target nrom <netrom-hostname>
5845 target remote <netrom-hostname>:1235
5849 GDB now includes support for the Apple Macintosh, as a host only. It
5850 may be run as either an MPW tool or as a standalone application, and
5851 it can debug through the serial port. All the usual GDB commands are
5852 available, but to the target command, you must supply "serial" as the
5853 device type instead of "/dev/ttyXX". See mpw-README in the main
5854 directory for more information on how to build. The MPW configuration
5855 scripts */mpw-config.in support only a few targets, and only the
5856 mips-idt-ecoff target has been tested.
5860 GDB configuration now uses autoconf. This is not user-visible,
5861 but does simplify configuration and building.
5865 GDB now supports hpux10.
5867 *** Changes in GDB-4.14:
5869 * New native configurations
5871 x86 FreeBSD i[345]86-*-freebsd
5872 x86 NetBSD i[345]86-*-netbsd
5873 NS32k NetBSD ns32k-*-netbsd
5874 Sparc NetBSD sparc-*-netbsd
5878 A29K VxWorks a29k-*-vxworks
5879 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5880 CPU32 EST-300 emulator m68*-*-est*
5881 PowerPC ELF powerpc-*-elf
5884 * Alpha OSF/1 support for procfs
5886 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5887 possible to attach to running processes. As the mounting of the /proc
5888 filesystem is optional on the Alpha, GDB automatically determines
5889 the availability of /proc during startup. This can lead to problems
5890 if /proc is unmounted after GDB has been started.
5892 * Arguments to user-defined commands
5894 User commands may accept up to 10 arguments separated by whitespace.
5895 Arguments are accessed within the user command via $arg0..$arg9. A
5898 print $arg0 + $arg1 + $arg2
5900 To execute the command use:
5903 Defines the command "adder" which prints the sum of its three arguments.
5904 Note the arguments are text substitutions, so they may reference variables,
5905 use complex expressions, or even perform inferior function calls.
5907 * New `if' and `while' commands
5909 This makes it possible to write more sophisticated user-defined
5910 commands. Both commands take a single argument, which is the
5911 expression to evaluate, and must be followed by the commands to
5912 execute, one per line, if the expression is nonzero, the list being
5913 terminated by the word `end'. The `if' command list may include an
5914 `else' word, which causes the following commands to be executed only
5915 if the expression is zero.
5917 * Fortran source language mode
5919 GDB now includes partial support for Fortran 77. It will recognize
5920 Fortran programs and can evaluate a subset of Fortran expressions, but
5921 variables and functions may not be handled correctly. GDB will work
5922 with G77, but does not yet know much about symbols emitted by other
5925 * Better HPUX support
5927 Most debugging facilities now work on dynamic executables for HPPAs
5928 running hpux9 or later. You can attach to running dynamically linked
5929 processes, but by default the dynamic libraries will be read-only, so
5930 for instance you won't be able to put breakpoints in them. To change
5931 that behavior do the following before running the program:
5937 This will cause the libraries to be mapped private and read-write.
5938 To revert to the normal behavior, do this:
5944 You cannot set breakpoints or examine data in the library until after
5945 the library is loaded if the function/data symbols do not have
5948 GDB can now also read debug symbols produced by the HP C compiler on
5949 HPPAs (sorry, no C++, Fortran or 68k support).
5951 * Target byte order now dynamically selectable
5953 You can choose which byte order to use with a target system, via the
5954 commands "set endian big" and "set endian little", and you can see the
5955 current setting by using "show endian". You can also give the command
5956 "set endian auto", in which case GDB will use the byte order
5957 associated with the executable. Currently, only embedded MIPS
5958 configurations support dynamic selection of target byte order.
5960 * New DOS host serial code
5962 This version uses DPMI interrupts to handle buffered I/O, so you
5963 no longer need to run asynctsr when debugging boards connected to
5966 *** Changes in GDB-4.13:
5968 * New "complete" command
5970 This lists all the possible completions for the rest of the line, if it
5971 were to be given as a command itself. This is intended for use by emacs.
5973 * Trailing space optional in prompt
5975 "set prompt" no longer adds a space for you after the prompt you set. This
5976 allows you to set a prompt which ends in a space or one that does not.
5978 * Breakpoint hit counts
5980 "info break" now displays a count of the number of times the breakpoint
5981 has been hit. This is especially useful in conjunction with "ignore"; you
5982 can ignore a large number of breakpoint hits, look at the breakpoint info
5983 to see how many times the breakpoint was hit, then run again, ignoring one
5984 less than that number, and this will get you quickly to the last hit of
5987 * Ability to stop printing at NULL character
5989 "set print null-stop" will cause GDB to stop printing the characters of
5990 an array when the first NULL is encountered. This is useful when large
5991 arrays actually contain only short strings.
5993 * Shared library breakpoints
5995 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5996 breakpoints in shared libraries before the executable is run.
5998 * Hardware watchpoints
6000 There is a new hardware breakpoint for the watch command for sparclite
6001 targets. See gdb/sparclite/hw_breakpoint.note.
6003 Hardware watchpoints are also now supported under GNU/Linux.
6007 Annotations have been added. These are for use with graphical interfaces,
6008 and are still experimental. Currently only gdba.el uses these.
6010 * Improved Irix 5 support
6012 GDB now works properly with Irix 5.2.
6014 * Improved HPPA support
6016 GDB now works properly with the latest GCC and GAS.
6018 * New native configurations
6020 Sequent PTX4 i[34]86-sequent-ptx4
6021 HPPA running OSF/1 hppa*-*-osf*
6022 Atari TT running SVR4 m68*-*-sysv4*
6023 RS/6000 LynxOS rs6000-*-lynxos*
6027 OS/9000 i[34]86-*-os9k
6028 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6031 * Hitachi SH7000 and E7000-PC ICE support
6033 There is now support for communicating with the Hitachi E7000-PC ICE.
6034 This is available automatically when GDB is configured for the SH.
6038 As usual, a variety of small fixes and improvements, both generic
6039 and configuration-specific. See the ChangeLog for more detail.
6041 *** Changes in GDB-4.12:
6043 * Irix 5 is now supported
6047 GDB-4.12 on the HPPA has a number of changes which make it unable
6048 to debug the output from the currently released versions of GCC and
6049 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6050 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6051 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6054 *** Changes in GDB-4.11:
6056 * User visible changes:
6060 The "set remotedebug" option is now consistent between the mips remote
6061 target, remote targets using the gdb-specific protocol, UDI (AMD's
6062 debug protocol for the 29k) and the 88k bug monitor. It is now an
6063 integer specifying a debug level (normally 0 or 1, but 2 means more
6064 debugging info for the mips target).
6066 * DEC Alpha native support
6068 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6069 debug info, but GDB works fairly well with the DEC compiler and should
6070 work with a future GCC release. See the README file for a few
6071 Alpha-specific notes.
6073 * Preliminary thread implementation
6075 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6077 * LynxOS native and target support for 386
6079 This release has been hosted on LynxOS 2.2, and also can be configured
6080 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6083 * Improvements in C++ mangling/demangling.
6085 This release has much better g++ debugging, specifically in name
6086 mangling/demangling, virtual function calls, print virtual table,
6087 call methods, ...etc.
6089 *** Changes in GDB-4.10:
6091 * User visible changes:
6093 Remote debugging using the GDB-specific (`target remote') protocol now
6094 supports the `load' command. This is only useful if you have some
6095 other way of getting the stub to the target system, and you can put it
6096 somewhere in memory where it won't get clobbered by the download.
6098 Filename completion now works.
6100 When run under emacs mode, the "info line" command now causes the
6101 arrow to point to the line specified. Also, "info line" prints
6102 addresses in symbolic form (as well as hex).
6104 All vxworks based targets now support a user settable option, called
6105 vxworks-timeout. This option represents the number of seconds gdb
6106 should wait for responses to rpc's. You might want to use this if
6107 your vxworks target is, perhaps, a slow software simulator or happens
6108 to be on the far side of a thin network line.
6112 This release contains support for using a DEC alpha as a GDB host for
6113 cross debugging. Native alpha debugging is not supported yet.
6116 *** Changes in GDB-4.9:
6120 This is the first GDB release which is accompanied by a matching testsuite.
6121 The testsuite requires installation of dejagnu, which should be available
6122 via ftp from most sites that carry GNU software.
6126 'Cfront' style demangling has had its name changed to 'ARM' style, to
6127 emphasize that it was written from the specifications in the C++ Annotated
6128 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6129 disclaimers, it still generated too much confusion with users attempting to
6130 use gdb with AT&T cfront.
6134 GDB now uses a standard remote interface to a simulator library.
6135 So far, the library contains simulators for the Zilog Z8001/2, the
6136 Hitachi H8/300, H8/500 and Super-H.
6138 * New targets supported
6140 H8/300 simulator h8300-hitachi-hms or h8300hms
6141 H8/500 simulator h8500-hitachi-hms or h8500hms
6142 SH simulator sh-hitachi-hms or sh
6143 Z8000 simulator z8k-zilog-none or z8ksim
6144 IDT MIPS board over serial line mips-idt-ecoff
6146 Cross-debugging to GO32 targets is supported. It requires a custom
6147 version of the i386-stub.c module which is integrated with the
6148 GO32 memory extender.
6150 * New remote protocols
6152 MIPS remote debugging protocol.
6154 * New source languages supported
6156 This version includes preliminary support for Chill, a Pascal like language
6157 used by telecommunications companies. Chill support is also being integrated
6158 into the GNU compiler, but we don't know when it will be publically available.
6161 *** Changes in GDB-4.8:
6163 * HP Precision Architecture supported
6165 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6166 version of this support was available as a set of patches from the
6167 University of Utah. GDB does not support debugging of programs
6168 compiled with the HP compiler, because HP will not document their file
6169 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6170 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6172 Many problems in the preliminary version have been fixed.
6174 * Faster and better demangling
6176 We have improved template demangling and fixed numerous bugs in the GNU style
6177 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6178 character types (wchar_t) are now supported. Demangling of each symbol is now
6179 only done once, and is cached when the symbol table for a file is read in.
6180 This results in a small increase in memory usage for C programs, a moderate
6181 increase in memory usage for C++ programs, and a fantastic speedup in
6184 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6185 from the specifications in the Annotated Reference Manual, which AT&T's
6186 compiler does not actually implement.
6188 * G++ multiple inheritance compiler problem
6190 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6191 inheritance lattices was reworked to properly discover ambiguities. We
6192 recently found an example which causes this new algorithm to fail in a
6193 very subtle way, producing bad debug information for those classes.
6194 The file 'gcc.patch' (in this directory) can be applied to gcc to
6195 circumvent the problem. A future GCC release will contain a complete
6198 The previous G++ debug info problem (mentioned below for the gdb-4.7
6199 release) is fixed in gcc version 2.3.2.
6201 * Improved configure script
6203 The `configure' script will now attempt to guess your system type if
6204 you don't supply a host system type. The old scheme of supplying a
6205 host system triplet is preferable over using this. All the magic is
6206 done in the new `config.guess' script. Examine it for details.
6208 We have also brought our configure script much more in line with the FSF's
6209 version. It now supports the --with-xxx options. In particular,
6210 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6211 The resulting GDB will not be able to read arbitrary object file formats --
6212 only the format ``expected'' to be used on the configured target system.
6213 We hope to make this the default in a future release.
6215 * Documentation improvements
6217 There's new internal documentation on how to modify GDB, and how to
6218 produce clean changes to the code. We implore people to read it
6219 before submitting changes.
6221 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6222 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6223 `info' files are also provided. To build `info' files from scratch,
6224 you will need the latest `makeinfo' release, which will be available in
6225 a future texinfo-X.Y release.
6227 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6228 We're not sure exactly which versions have this problem, but it has
6229 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6230 or better. If that isn't possible, there is a patch in
6231 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6232 around this problem.
6236 GDB now supports array constants that can be used in expressions typed in by
6237 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6238 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6241 The new directory `gdb/sparclite' contains a program that demonstrates
6242 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6244 * New native hosts supported
6246 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6247 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6249 * New targets supported
6251 AMD 29k family via UDI a29k-amd-udi or udi29k
6253 * New file formats supported
6255 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6256 HPUX core files, and SCO 3.2v2 core files.
6260 Attaching to processes now works again; thanks for the many bug reports.
6262 We have also stomped on a bunch of core dumps caused by
6263 printf_filtered("%s") problems.
6265 We eliminated a copyright problem on the rpc and ptrace header files
6266 for VxWorks, which was discovered at the last minute during the 4.7
6267 release. You should now be able to build a VxWorks GDB.
6269 You can now interrupt gdb while an attached process is running. This
6270 will cause the attached process to stop, and give control back to GDB.
6272 We fixed problems caused by using too many file descriptors
6273 for reading symbols from object files and libraries. This was
6274 especially a problem for programs that used many (~100) shared
6277 The `step' command now only enters a subroutine if there is line number
6278 information for the subroutine. Otherwise it acts like the `next'
6279 command. Previously, `step' would enter subroutines if there was
6280 any debugging information about the routine. This avoids problems
6281 when using `cc -g1' on MIPS machines.
6283 * Internal improvements
6285 GDB's internal interfaces have been improved to make it easier to support
6286 debugging of multiple languages in the future.
6288 GDB now uses a common structure for symbol information internally.
6289 Minimal symbols (derived from linkage symbols in object files), partial
6290 symbols (from a quick scan of debug information), and full symbols
6291 contain a common subset of information, making it easier to write
6292 shared code that handles any of them.
6294 * New command line options
6296 We now accept --silent as an alias for --quiet.
6300 The memory-mapped-malloc library is now licensed under the GNU Library
6301 General Public License.
6303 *** Changes in GDB-4.7:
6305 * Host/native/target split
6307 GDB has had some major internal surgery to untangle the support for
6308 hosts and remote targets. Now, when you configure GDB for a remote
6309 target, it will no longer load in all of the support for debugging
6310 local programs on the host. When fully completed and tested, this will
6311 ensure that arbitrary host/target combinations are possible.
6313 The primary conceptual shift is to separate the non-portable code in
6314 GDB into three categories. Host specific code is required any time GDB
6315 is compiled on that host, regardless of the target. Target specific
6316 code relates to the peculiarities of the target, but can be compiled on
6317 any host. Native specific code is everything else: it can only be
6318 built when the host and target are the same system. Child process
6319 handling and core file support are two common `native' examples.
6321 GDB's use of /proc for controlling Unix child processes is now cleaner.
6322 It has been split out into a single module under the `target_ops' vector,
6323 plus two native-dependent functions for each system that uses /proc.
6325 * New hosts supported
6327 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6328 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6329 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6331 * New targets supported
6333 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6334 68030 and CPU32 m68030-*-*, m68332-*-*
6336 * New native hosts supported
6338 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6339 (386bsd is not well tested yet)
6340 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6342 * New file formats supported
6344 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6345 supports reading of `a.out.adobe' object files, which are an a.out
6346 format extended with minimal information about multiple sections.
6350 `show copying' is the same as the old `info copying'.
6351 `show warranty' is the same as `info warrantee'.
6352 These were renamed for consistency. The old commands continue to work.
6354 `info handle' is a new alias for `info signals'.
6356 You can now define pre-command hooks, which attach arbitrary command
6357 scripts to any command. The commands in the hook will be executed
6358 prior to the user's command. You can also create a hook which will be
6359 executed whenever the program stops. See gdb.texinfo.
6363 We now deal with Cfront style name mangling, and can even extract type
6364 info from mangled symbols. GDB can automatically figure out which
6365 symbol mangling style your C++ compiler uses.
6367 Calling of methods and virtual functions has been improved as well.
6371 The crash that occured when debugging Sun Ansi-C compiled binaries is
6372 fixed. This was due to mishandling of the extra N_SO stabs output
6375 We also finally got Ultrix 4.2 running in house, and fixed core file
6376 support, with help from a dozen people on the net.
6378 John M. Farrell discovered that the reason that single-stepping was so
6379 slow on all of the Mips based platforms (primarily SGI and DEC) was
6380 that we were trying to demangle and lookup a symbol used for internal
6381 purposes on every instruction that was being stepped through. Changing
6382 the name of that symbol so that it couldn't be mistaken for a C++
6383 mangled symbol sped things up a great deal.
6385 Rich Pixley sped up symbol lookups in general by getting much smarter
6386 about when C++ symbol mangling is necessary. This should make symbol
6387 completion (TAB on the command line) much faster. It's not as fast as
6388 we'd like, but it's significantly faster than gdb-4.6.
6392 A new user controllable variable 'call_scratch_address' can
6393 specify the location of a scratch area to be used when GDB
6394 calls a function in the target. This is necessary because the
6395 usual method of putting the scratch area on the stack does not work
6396 in systems that have separate instruction and data spaces.
6398 We integrated changes to support the 29k UDI (Universal Debugger
6399 Interface), but discovered at the last minute that we didn't have all
6400 of the appropriate copyright paperwork. We are working with AMD to
6401 resolve this, and hope to have it available soon.
6405 We have sped up the remote serial line protocol, especially for targets
6406 with lots of registers. It now supports a new `expedited status' ('T')
6407 message which can be used in place of the existing 'S' status message.
6408 This allows the remote stub to send only the registers that GDB
6409 needs to make a quick decision about single-stepping or conditional
6410 breakpoints, eliminating the need to fetch the entire register set for
6411 each instruction being stepped through.
6413 The GDB remote serial protocol now implements a write-through cache for
6414 registers, only re-reading the registers if the target has run.
6416 There is also a new remote serial stub for SPARC processors. You can
6417 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6418 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6419 processor with a serial port.
6423 Configure.in files have become much easier to read and modify. A new
6424 `table driven' format makes it more obvious what configurations are
6425 supported, and what files each one uses.
6429 There is a new opcodes library which will eventually contain all of the
6430 disassembly routines and opcode tables. At present, it only contains
6431 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6432 disassembler (binutils/objdump) to share these routines.
6434 The libiberty library is now copylefted under the GNU Library General
6435 Public License. This allows more liberal use, and was done so libg++
6436 can use it. This makes no difference to GDB, since the Library License
6437 grants all the rights from the General Public License.
6441 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6442 reference to the stabs symbol info used by the debugger. It is (as far
6443 as we know) the only published document on this fascinating topic. We
6444 encourage you to read it, compare it to the stabs information on your
6445 system, and send improvements on the document in general (to
6446 bug-gdb@prep.ai.mit.edu).
6448 And, of course, many bugs have been fixed.
6451 *** Changes in GDB-4.6:
6453 * Better support for C++ function names
6455 GDB now accepts as input the "demangled form" of C++ overloaded function
6456 names and member function names, and can do command completion on such names
6457 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6458 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6459 Make use of command completion, it is your friend.
6461 GDB also now accepts a variety of C++ mangled symbol formats. They are
6462 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6463 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6464 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6465 for the list of formats.
6467 * G++ symbol mangling problem
6469 Recent versions of gcc have a bug in how they emit debugging information for
6470 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6471 directory) can be applied to gcc to fix the problem. Alternatively, if you
6472 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6473 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6474 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6477 * New 'maintenance' command
6479 All of the commands related to hacking GDB internals have been moved out of
6480 the main command set, and now live behind the 'maintenance' command. This
6481 can also be abbreviated as 'mt'. The following changes were made:
6483 dump-me -> maintenance dump-me
6484 info all-breakpoints -> maintenance info breakpoints
6485 printmsyms -> maintenance print msyms
6486 printobjfiles -> maintenance print objfiles
6487 printpsyms -> maintenance print psymbols
6488 printsyms -> maintenance print symbols
6490 The following commands are new:
6492 maintenance demangle Call internal GDB demangler routine to
6493 demangle a C++ link name and prints the result.
6494 maintenance print type Print a type chain for a given symbol
6496 * Change to .gdbinit file processing
6498 We now read the $HOME/.gdbinit file before processing the argv arguments
6499 (e.g. reading symbol files or core files). This allows global parameters to
6500 be set, which will apply during the symbol reading. The ./.gdbinit is still
6501 read after argv processing.
6503 * New hosts supported
6505 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6507 GNU/Linux support i386-unknown-linux or linux
6509 We are also including code to support the HP/PA running BSD and HPUX. This
6510 is almost guaranteed not to work, as we didn't have time to test or build it
6511 for this release. We are including it so that the more adventurous (or
6512 masochistic) of you can play with it. We also had major problems with the
6513 fact that the compiler that we got from HP doesn't support the -g option.
6516 * New targets supported
6518 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6520 * More smarts about finding #include files
6522 GDB now remembers the compilation directory for all include files, and for
6523 all files from which C is generated (like yacc and lex sources). This
6524 greatly improves GDB's ability to find yacc/lex sources, and include files,
6525 especially if you are debugging your program from a directory different from
6526 the one that contains your sources.
6528 We also fixed a bug which caused difficulty with listing and setting
6529 breakpoints in include files which contain C code. (In the past, you had to
6530 try twice in order to list an include file that you hadn't looked at before.)
6532 * Interesting infernals change
6534 GDB now deals with arbitrary numbers of sections, where the symbols for each
6535 section must be relocated relative to that section's landing place in the
6536 target's address space. This work was needed to support ELF with embedded
6537 stabs used by Solaris-2.0.
6539 * Bug fixes (of course!)
6541 There have been loads of fixes for the following things:
6542 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6543 i960, stabs, DOS(GO32), procfs, etc...
6545 See the ChangeLog for details.
6547 *** Changes in GDB-4.5:
6549 * New machines supported (host and target)
6551 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6553 SGI Irix-4.x mips-sgi-irix4 or iris4
6555 * New malloc package
6557 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6558 Mmalloc is capable of handling mutiple heaps of memory. It is also
6559 capable of saving a heap to a file, and then mapping it back in later.
6560 This can be used to greatly speedup the startup of GDB by using a
6561 pre-parsed symbol table which lives in a mmalloc managed heap. For
6562 more details, please read mmalloc/mmalloc.texi.
6566 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6567 'help info proc' for details.
6569 * MIPS ecoff symbol table format
6571 The code that reads MIPS symbol table format is now supported on all hosts.
6572 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6575 * File name changes for MS-DOS
6577 Many files in the config directories have been renamed to make it easier to
6578 support GDB on MS-DOSe systems (which have very restrictive file name
6579 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6580 environment) is close to working but has some remaining problems. Note
6581 that debugging of DOS programs is not supported, due to limitations
6582 in the ``operating system'', but it can be used to host cross-debugging.
6584 * Cross byte order fixes
6586 Many fixes have been made to support cross debugging of Sparc and MIPS
6587 targets from hosts whose byte order differs.
6589 * New -mapped and -readnow options
6591 If memory-mapped files are available on your system through the 'mmap'
6592 system call, you can use the -mapped option on the `file' or
6593 `symbol-file' commands to cause GDB to write the symbols from your
6594 program into a reusable file. If the program you are debugging is
6595 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6596 Future GDB debugging sessions will notice the presence of this file,
6597 and will quickly map in symbol information from it, rather than reading
6598 the symbol table from the executable program. Using the '-mapped'
6599 option in a GDB `file' or `symbol-file' command has the same effect as
6600 starting GDB with the '-mapped' command-line option.
6602 You can cause GDB to read the entire symbol table immediately by using
6603 the '-readnow' option with any of the commands that load symbol table
6604 information (or on the GDB command line). This makes the command
6605 slower, but makes future operations faster.
6607 The -mapped and -readnow options are typically combined in order to
6608 build a `fred.syms' file that contains complete symbol information.
6609 A simple GDB invocation to do nothing but build a `.syms' file for future
6612 gdb -batch -nx -mapped -readnow programname
6614 The `.syms' file is specific to the host machine on which GDB is run.
6615 It holds an exact image of GDB's internal symbol table. It cannot be
6616 shared across multiple host platforms.
6618 * longjmp() handling
6620 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6621 siglongjmp() without losing control. This feature has not yet been ported to
6622 all systems. It currently works on many 386 platforms, all MIPS-based
6623 platforms (SGI, DECstation, etc), and Sun3/4.
6627 Preliminary work has been put in to support the new Solaris OS from Sun. At
6628 this time, it can control and debug processes, but it is not capable of
6633 As always, many many bug fixes. The major areas were with g++, and mipsread.
6634 People using the MIPS-based platforms should experience fewer mysterious
6635 crashes and trashed symbol tables.
6637 *** Changes in GDB-4.4:
6639 * New machines supported (host and target)
6641 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6643 BSD Reno on Vax vax-dec-bsd
6644 Ultrix on Vax vax-dec-ultrix
6646 * New machines supported (target)
6648 AMD 29000 embedded, using EBMON a29k-none-none
6652 GDB continues to improve its handling of C++. `References' work better.
6653 The demangler has also been improved, and now deals with symbols mangled as
6654 per the Annotated C++ Reference Guide.
6656 GDB also now handles `stabs' symbol information embedded in MIPS
6657 `ecoff' symbol tables. Since the ecoff format was not easily
6658 extensible to handle new languages such as C++, this appeared to be a
6659 good way to put C++ debugging info into MIPS binaries. This option
6660 will be supported in the GNU C compiler, version 2, when it is
6663 * New features for SVR4
6665 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6666 shared libraries. Debugging dynamically linked programs should present
6667 only minor differences from debugging statically linked programs.
6669 The `info proc' command will print out information about any process
6670 on an SVR4 system (including the one you are debugging). At the moment,
6671 it prints the address mappings of the process.
6673 If you bring up GDB on another SVR4 system, please send mail to
6674 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6676 * Better dynamic linking support in SunOS
6678 Reading symbols from shared libraries which contain debugging symbols
6679 now works properly. However, there remain issues such as automatic
6680 skipping of `transfer vector' code during function calls, which
6681 make it harder to debug code in a shared library, than to debug the
6682 same code linked statically.
6686 GDB is now using the latest `getopt' routines from the FSF. This
6687 version accepts the -- prefix for options with long names. GDB will
6688 continue to accept the old forms (-option and +option) as well.
6689 Various single letter abbreviations for options have been explicity
6690 added to the option table so that they won't get overshadowed in the
6691 future by other options that begin with the same letter.
6695 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6696 Many assorted bugs have been handled. Many more remain to be handled.
6697 See the various ChangeLog files (primarily in gdb and bfd) for details.
6700 *** Changes in GDB-4.3:
6702 * New machines supported (host and target)
6704 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6705 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6706 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6708 * Almost SCO Unix support
6710 We had hoped to support:
6711 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6712 (except for core file support), but we discovered very late in the release
6713 that it has problems with process groups that render gdb unusable. Sorry
6714 about that. I encourage people to fix it and post the fixes.
6716 * Preliminary ELF and DWARF support
6718 GDB can read ELF object files on System V Release 4, and can handle
6719 debugging records for C, in DWARF format, in ELF files. This support
6720 is preliminary. If you bring up GDB on another SVR4 system, please
6721 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6726 GDB now uses the latest `readline' library. One user-visible change
6727 is that two tabs will list possible command completions, which previously
6728 required typing M-? (meta-question mark, or ESC ?).
6732 The `stepi' bug that many of you noticed has been squashed.
6733 Many bugs in C++ have been handled. Many more remain to be handled.
6734 See the various ChangeLog files (primarily in gdb and bfd) for details.
6736 * State of the MIPS world (in case you wondered):
6738 GDB can understand the symbol tables emitted by the compilers
6739 supplied by most vendors of MIPS-based machines, including DEC. These
6740 symbol tables are in a format that essentially nobody else uses.
6742 Some versions of gcc come with an assembler post-processor called
6743 mips-tfile. This program is required if you want to do source-level
6744 debugging of gcc-compiled programs. I believe FSF does not ship
6745 mips-tfile with gcc version 1, but it will eventually come with gcc
6748 Debugging of g++ output remains a problem. g++ version 1.xx does not
6749 really support it at all. (If you're lucky, you should be able to get
6750 line numbers and stack traces to work, but no parameters or local
6751 variables.) With some work it should be possible to improve the
6754 When gcc version 2 is released, you will have somewhat better luck.
6755 However, even then you will get confusing results for inheritance and
6758 We will eventually provide full debugging of g++ output on
6759 DECstations. This will probably involve some kind of stabs-in-ecoff
6760 encapulation, but the details have not been worked out yet.
6763 *** Changes in GDB-4.2:
6765 * Improved configuration
6767 Only one copy of `configure' exists now, and it is not self-modifying.
6768 Porting BFD is simpler.
6772 The `step' and `next' commands now only stop at the first instruction
6773 of a source line. This prevents the multiple stops that used to occur
6774 in switch statements, for-loops, etc. `Step' continues to stop if a
6775 function that has debugging information is called within the line.
6779 Lots of small bugs fixed. More remain.
6781 * New host supported (not target)
6783 Intel 386 PC clone running Mach i386-none-mach
6786 *** Changes in GDB-4.1:
6788 * Multiple source language support
6790 GDB now has internal scaffolding to handle several source languages.
6791 It determines the type of each source file from its filename extension,
6792 and will switch expression parsing and number formatting to match the
6793 language of the function in the currently selected stack frame.
6794 You can also specifically set the language to be used, with
6795 `set language c' or `set language modula-2'.
6799 GDB now has preliminary support for the GNU Modula-2 compiler,
6800 currently under development at the State University of New York at
6801 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6802 continue through the fall of 1991 and into 1992.
6804 Other Modula-2 compilers are currently not supported, and attempting to
6805 debug programs compiled with them will likely result in an error as the
6806 symbol table is read. Feel free to work on it, though!
6808 There are hooks in GDB for strict type checking and range checking,
6809 in the `Modula-2 philosophy', but they do not currently work.
6813 GDB can now write to executable and core files (e.g. patch
6814 a variable's value). You must turn this switch on, specify
6815 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6816 by assigning a new value to a variable. Modifications take
6819 * Automatic SunOS shared library reading
6821 When you run your program, GDB automatically determines where its
6822 shared libraries (if any) have been loaded, and reads their symbols.
6823 The `share' command is no longer needed. This also works when
6824 examining core files.
6828 You can specify the number of lines that the `list' command shows.
6831 * New machines supported (host and target)
6833 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6834 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6835 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6837 * New hosts supported (not targets)
6839 IBM RT/PC: romp-ibm-aix or rtpc
6841 * New targets supported (not hosts)
6843 AMD 29000 embedded with COFF a29k-none-coff
6844 AMD 29000 embedded with a.out a29k-none-aout
6845 Ultracomputer remote kernel debug a29k-nyu-kern
6847 * New remote interfaces
6853 *** Changes in GDB-4.0:
6857 Wide output is wrapped at good places to make the output more readable.
6859 Gdb now supports cross-debugging from a host machine of one type to a
6860 target machine of another type. Communication with the target system
6861 is over serial lines. The ``target'' command handles connecting to the
6862 remote system; the ``load'' command will download a program into the
6863 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6864 also supports debugging of realtime processes running under VxWorks,
6865 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6866 stub on the target system.
6868 New CPUs supported include the AMD 29000 and Intel 960.
6870 GDB now reads object files and symbol tables via a ``binary file''
6871 library, which allows a single copy of GDB to debug programs of multiple
6872 object file types such as a.out and coff.
6874 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6875 refcard.dvi and refcard.ps are available to format it).
6878 * Control-Variable user interface simplified
6880 All variables that control the operation of the debugger can be set
6881 by the ``set'' command, and displayed by the ``show'' command.
6883 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6884 ``Show prompt'' produces the response:
6885 Gdb's prompt is new-gdb=>.
6887 What follows are the NEW set commands. The command ``help set'' will
6888 print a complete list of old and new set commands. ``help set FOO''
6889 will give a longer description of the variable FOO. ``show'' will show
6890 all of the variable descriptions and their current settings.
6892 confirm on/off: Enables warning questions for operations that are
6893 hard to recover from, e.g. rerunning the program while
6894 it is already running. Default is ON.
6896 editing on/off: Enables EMACS style command line editing
6897 of input. Previous lines can be recalled with
6898 control-P, the current line can be edited with control-B,
6899 you can search for commands with control-R, etc.
6902 history filename NAME: NAME is where the gdb command history
6903 will be stored. The default is .gdb_history,
6904 or the value of the environment variable
6907 history size N: The size, in commands, of the command history. The
6908 default is 256, or the value of the environment variable
6911 history save on/off: If this value is set to ON, the history file will
6912 be saved after exiting gdb. If set to OFF, the
6913 file will not be saved. The default is OFF.
6915 history expansion on/off: If this value is set to ON, then csh-like
6916 history expansion will be performed on
6917 command line input. The default is OFF.
6919 radix N: Sets the default radix for input and output. It can be set
6920 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6921 in the current radix, so "set radix 10" is always a no-op.
6923 height N: This integer value is the number of lines on a page. Default
6924 is 24, the current `stty rows'' setting, or the ``li#''
6925 setting from the termcap entry matching the environment
6928 width N: This integer value is the number of characters on a line.
6929 Default is 80, the current `stty cols'' setting, or the ``co#''
6930 setting from the termcap entry matching the environment
6933 Note: ``set screensize'' is obsolete. Use ``set height'' and
6934 ``set width'' instead.
6936 print address on/off: Print memory addresses in various command displays,
6937 such as stack traces and structure values. Gdb looks
6938 more ``symbolic'' if you turn this off; it looks more
6939 ``machine level'' with it on. Default is ON.
6941 print array on/off: Prettyprint arrays. New convenient format! Default
6944 print demangle on/off: Print C++ symbols in "source" form if on,
6947 print asm-demangle on/off: Same, for assembler level printouts
6950 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6953 * Support for Epoch Environment.
6955 The epoch environment is a version of Emacs v18 with windowing. One
6956 new command, ``inspect'', is identical to ``print'', except that if you
6957 are running in the epoch environment, the value is printed in its own
6961 * Support for Shared Libraries
6963 GDB can now debug programs and core files that use SunOS shared libraries.
6964 Symbols from a shared library cannot be referenced
6965 before the shared library has been linked with the program (this
6966 happens after you type ``run'' and before the function main() is entered).
6967 At any time after this linking (including when examining core files
6968 from dynamically linked programs), gdb reads the symbols from each
6969 shared library when you type the ``sharedlibrary'' command.
6970 It can be abbreviated ``share''.
6972 sharedlibrary REGEXP: Load shared object library symbols for files
6973 matching a unix regular expression. No argument
6974 indicates to load symbols for all shared libraries.
6976 info sharedlibrary: Status of loaded shared libraries.
6981 A watchpoint stops execution of a program whenever the value of an
6982 expression changes. Checking for this slows down execution
6983 tremendously whenever you are in the scope of the expression, but is
6984 quite useful for catching tough ``bit-spreader'' or pointer misuse
6985 problems. Some machines such as the 386 have hardware for doing this
6986 more quickly, and future versions of gdb will use this hardware.
6988 watch EXP: Set a watchpoint (breakpoint) for an expression.
6990 info watchpoints: Information about your watchpoints.
6992 delete N: Deletes watchpoint number N (same as breakpoints).
6993 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6994 enable N: Re-enables watchpoint number N (same as breakpoints).
6997 * C++ multiple inheritance
6999 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7002 * C++ exception handling
7004 Gdb now supports limited C++ exception handling. Besides the existing
7005 ability to breakpoint on an exception handler, gdb can breakpoint on
7006 the raising of an exception (before the stack is peeled back to the
7009 catch FOO: If there is a FOO exception handler in the dynamic scope,
7010 set a breakpoint to catch exceptions which may be raised there.
7011 Multiple exceptions (``catch foo bar baz'') may be caught.
7013 info catch: Lists all exceptions which may be caught in the
7014 current stack frame.
7017 * Minor command changes
7019 The command ``call func (arg, arg, ...)'' now acts like the print
7020 command, except it does not print or save a value if the function's result
7021 is void. This is similar to dbx usage.
7023 The ``up'' and ``down'' commands now always print the frame they end up
7024 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7025 frames without printing.
7027 * New directory command
7029 'dir' now adds directories to the FRONT of the source search path.
7030 The path starts off empty. Source files that contain debug information
7031 about the directory in which they were compiled can be found even
7032 with an empty path; Sun CC and GCC include this information. If GDB can't
7033 find your source file in the current directory, type "dir .".
7035 * Configuring GDB for compilation
7037 For normal use, type ``./configure host''. See README or gdb.texinfo
7040 GDB now handles cross debugging. If you are remotely debugging between
7041 two different machines, type ``./configure host -target=targ''.
7042 Host is the machine where GDB will run; targ is the machine
7043 where the program that you are debugging will run.