1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.1
6 * The endianness used with the 'set endian auto' mode in the absence of
7 an executable selected for debugging is now the last endianness chosen
8 either by one of the 'set endian big' and 'set endian little' commands
9 or by inferring from the last executable used, rather than the startup
12 * The pager now allows a "c" response, meaning to disable the pager
13 for the rest of the current command.
15 * The commands 'info variables/functions/types' now show the source line
16 numbers of symbol definitions when available.
18 * 'info proc' now works on running processes on FreeBSD systems and core
19 files created on FreeBSD systems.
21 * C expressions can now use _Alignof, and C++ expressions can now use
28 Control display of debugging info regarding the FreeBSD native target.
30 set|show varsize-limit
31 This new setting allows the user to control the maximum size of Ada
32 objects being printed when those objects have a variable type,
33 instead of that maximum size being hardcoded to 65536 bytes.
35 set|show record btrace cpu
36 Controls the processor to be used for enabling errata workarounds for
39 maint check libthread-db
40 Run integrity checks on the current inferior's thread debugging
43 maint set check-libthread-db (on|off)
44 maint show check-libthread-db
45 Control whether to run integrity checks on inferior specific thread
46 debugging libraries as they are loaded. The default is not to
51 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
53 ** The commands attached to a breakpoint can be set by assigning to
54 the breakpoint's "commands" field.
56 ** gdb.execute can now execute multi-line gdb commands.
58 ** The new functions gdb.convenience_variable and
59 gdb.set_convenience_variable can be used to get and set the value
60 of convenience variables.
62 ** A gdb.Parameter will no longer print the "set" help text on an
63 ordinary "set"; instead by default a "set" will be silent unless
64 the get_set_string method returns a non-empty string.
68 RiscV ELF riscv*-*-elf
70 * Removed targets and native configurations
72 m88k running OpenBSD m88*-*-openbsd*
73 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
74 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
75 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
77 * Aarch64/Linux hardware watchpoints improvements
79 Hardware watchpoints on unaligned addresses are now properly
80 supported when running Linux kernel 4.10 or higher: read and access
81 watchpoints are no longer spuriously missed, and all watchpoints
82 lengths between 1 and 8 bytes are supported. On older kernels,
83 watchpoints set on unaligned addresses are no longer missed, with
84 the tradeoff that there is a possibility of false hits being
87 *** Changes in GDB 8.1
89 * GDB now supports dynamically creating arbitrary register groups specified
90 in XML target descriptions. This allows for finer grain grouping of
91 registers on systems with a large amount of registers.
93 * The 'ptype' command now accepts a '/o' flag, which prints the
94 offsets and sizes of fields in a struct, like the pahole(1) tool.
96 * New "--readnever" command line option instructs GDB to not read each
97 symbol file's symbolic debug information. This makes startup faster
98 but at the expense of not being able to perform symbolic debugging.
99 This option is intended for use cases where symbolic debugging will
100 not be used, e.g., when you only need to dump the debuggee's core.
102 * GDB now uses the GNU MPFR library, if available, to emulate target
103 floating-point arithmetic during expression evaluation when the target
104 uses different floating-point formats than the host. At least version
105 3.1 of GNU MPFR is required.
107 * GDB now supports access to the guarded-storage-control registers and the
108 software-based guarded-storage broadcast control registers on IBM z14.
110 * On Unix systems, GDB now supports transmitting environment variables
111 that are to be set or unset to GDBserver. These variables will
112 affect the environment to be passed to the remote inferior.
114 To inform GDB of environment variables that are to be transmitted to
115 GDBserver, use the "set environment" command. Only user set
116 environment variables are sent to GDBserver.
118 To inform GDB of environment variables that are to be unset before
119 the remote inferior is started by the GDBserver, use the "unset
120 environment" command.
122 * Completion improvements
124 ** GDB can now complete function parameters in linespecs and
125 explicit locations without quoting. When setting breakpoints,
126 quoting around functions names to help with TAB-completion is
127 generally no longer necessary. For example, this now completes
130 (gdb) b function(in[TAB]
131 (gdb) b function(int)
133 Related, GDB is no longer confused with completing functions in
134 C++ anonymous namespaces:
137 (gdb) b (anonymous namespace)::[TAB][TAB]
138 (anonymous namespace)::a_function()
139 (anonymous namespace)::b_function()
141 ** GDB now has much improved linespec and explicit locations TAB
142 completion support, that better understands what you're
143 completing and offers better suggestions. For example, GDB no
144 longer offers data symbols as possible completions when you're
145 setting a breakpoint.
147 ** GDB now TAB-completes label symbol names.
149 ** The "complete" command now mimics TAB completion accurately.
151 * New command line options (gcore)
154 Dump all memory mappings.
156 * Breakpoints on C++ functions are now set on all scopes by default
158 By default, breakpoints on functions/methods are now interpreted as
159 specifying all functions with the given name ignoring missing
160 leading scopes (namespaces and classes).
162 For example, assuming a C++ program with symbols named:
167 both commands "break func()" and "break B::func()" set a breakpoint
170 You can use the new flag "-qualified" to override this. This makes
171 GDB interpret the specified function name as a complete
172 fully-qualified name instead. For example, using the same C++
173 program, the "break -q B::func" command sets a breakpoint on
174 "B::func", only. A parameter has been added to the Python
175 gdb.Breakpoint constructor to achieve the same result when creating
176 a breakpoint from Python.
178 * Breakpoints on functions marked with C++ ABI tags
180 GDB can now set breakpoints on functions marked with C++ ABI tags
181 (e.g., [abi:cxx11]). See here for a description of ABI tags:
182 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
184 Functions with a C++11 abi tag are demangled/displayed like this:
186 function[abi:cxx11](int)
189 You can now set a breakpoint on such functions simply as if they had
192 (gdb) b function(int)
194 Or if you need to disambiguate between tags, like:
196 (gdb) b function[abi:other_tag](int)
198 Tab completion was adjusted accordingly as well.
202 ** New events gdb.new_inferior, gdb.inferior_deleted, and
203 gdb.new_thread are emitted. See the manual for further
204 description of these.
206 ** A new function, "gdb.rbreak" has been added to the Python API.
207 This function allows the setting of a large number of breakpoints
208 via a regex pattern in Python. See the manual for further details.
210 ** Python breakpoints can now accept explicit locations. See the
211 manual for a further description of this feature.
214 * New features in the GDB remote stub, GDBserver
216 ** GDBserver is now able to start inferior processes with a
217 specified initial working directory.
219 The user can set the desired working directory to be used from
220 GDB using the new "set cwd" command.
222 ** New "--selftest" command line option runs some GDBserver self
223 tests. These self tests are disabled in releases.
225 ** On Unix systems, GDBserver now does globbing expansion and variable
226 substitution in inferior command line arguments.
228 This is done by starting inferiors using a shell, like GDB does.
229 See "set startup-with-shell" in the user manual for how to disable
230 this from GDB when using "target extended-remote". When using
231 "target remote", you can disable the startup with shell by using the
232 new "--no-startup-with-shell" GDBserver command line option.
234 ** On Unix systems, GDBserver now supports receiving environment
235 variables that are to be set or unset from GDB. These variables
236 will affect the environment to be passed to the inferior.
238 * When catching an Ada exception raised with a message, GDB now prints
239 the message in the catchpoint hit notification. In GDB/MI mode, that
240 information is provided as an extra field named "exception-message"
241 in the *stopped notification.
243 * Trait objects can now be inspected When debugging Rust code. This
244 requires compiler support which will appear in Rust 1.24.
248 QEnvironmentHexEncoded
249 Inform GDBserver of an environment variable that is to be passed to
250 the inferior when starting it.
253 Inform GDBserver of an environment variable that is to be unset
254 before starting the remote inferior.
257 Inform GDBserver that the environment should be reset (i.e.,
258 user-set environment variables should be unset).
261 Indicates whether the inferior must be started with a shell or not.
264 Tell GDBserver that the inferior to be started should use a specific
267 * The "maintenance print c-tdesc" command now takes an optional
268 argument which is the file name of XML target description.
270 * The "maintenance selftest" command now takes an optional argument to
271 filter the tests to be run.
273 * The "enable", and "disable" commands now accept a range of
274 breakpoint locations, e.g. "enable 1.3-5".
279 Set and show the current working directory for the inferior.
282 Set and show compilation command used for compiling and injecting code
283 with the 'compile' commands.
285 set debug separate-debug-file
286 show debug separate-debug-file
287 Control the display of debug output about separate debug file search.
289 set dump-excluded-mappings
290 show dump-excluded-mappings
291 Control whether mappings marked with the VM_DONTDUMP flag should be
292 dumped when generating a core file.
295 List the registered selftests.
298 Start the debugged program stopping at the first instruction.
301 Control display of debugging messages related to OpenRISC targets.
303 set|show print type nested-type-limit
304 Set and show the limit of nesting level for nested types that the
305 type printer will show.
307 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
310 * Safer/improved support for debugging with no debug info
312 GDB no longer assumes functions with no debug information return
315 This means that GDB now refuses to call such functions unless you
316 tell it the function's type, by either casting the call to the
317 declared return type, or by casting the function to a function
318 pointer of the right type, and calling that:
320 (gdb) p getenv ("PATH")
321 'getenv' has unknown return type; cast the call to its declared return type
322 (gdb) p (char *) getenv ("PATH")
323 $1 = 0x7fffffffe "/usr/local/bin:/"...
324 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
325 $2 = 0x7fffffffe "/usr/local/bin:/"...
327 Similarly, GDB no longer assumes that global variables with no debug
328 info have type 'int', and refuses to print the variable's value
329 unless you tell it the variable's type:
332 'var' has unknown type; cast it to its declared type
336 * New native configurations
338 FreeBSD/aarch64 aarch64*-*-freebsd*
339 FreeBSD/arm arm*-*-freebsd*
343 FreeBSD/aarch64 aarch64*-*-freebsd*
344 FreeBSD/arm arm*-*-freebsd*
345 OpenRISC ELF or1k*-*-elf
347 * Removed targets and native configurations
349 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
351 *** Changes in GDB 8.0
353 * GDB now supports access to the PKU register on GNU/Linux. The register is
354 added by the Memory Protection Keys for Userspace feature which will be
355 available in future Intel CPUs.
357 * GDB now supports C++11 rvalue references.
361 ** New functions to start, stop and access a running btrace recording.
362 ** Rvalue references are now supported in gdb.Type.
364 * GDB now supports recording and replaying rdrand and rdseed Intel 64
367 * Building GDB and GDBserver now requires a C++11 compiler.
369 For example, GCC 4.8 or later.
371 It is no longer possible to build GDB or GDBserver with a C
372 compiler. The --disable-build-with-cxx configure option has been
375 * Building GDB and GDBserver now requires GNU make >= 3.81.
377 It is no longer supported to build GDB or GDBserver with another
378 implementation of the make program or an earlier version of GNU make.
380 * Native debugging on MS-Windows supports command-line redirection
382 Command-line arguments used for starting programs on MS-Windows can
383 now include redirection symbols supported by native Windows shells,
384 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
385 as "run", "start", and "set args", as well as the corresponding MI
388 * Support for thread names on MS-Windows.
390 GDB now catches and handles the special exception that programs
391 running on MS-Windows use to assign names to threads in the
394 * Support for Java programs compiled with gcj has been removed.
396 * User commands now accept an unlimited number of arguments.
397 Previously, only up to 10 was accepted.
399 * The "eval" command now expands user-defined command arguments.
401 This makes it easier to process a variable number of arguments:
406 eval "print $arg%d", $i
411 * Target descriptions can now describe registers for sparc32 and sparc64.
413 * GDB now supports DWARF version 5 (debug information format).
414 Its .debug_names index is not yet supported.
416 * New native configurations
418 FreeBSD/mips mips*-*-freebsd
422 Synopsys ARC arc*-*-elf32
423 FreeBSD/mips mips*-*-freebsd
425 * Removed targets and native configurations
427 Alpha running FreeBSD alpha*-*-freebsd*
428 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
433 Erases all the flash memory regions reported by the target.
435 maint print arc arc-instruction address
436 Print internal disassembler information about instruction at a given address.
440 set disassembler-options
441 show disassembler-options
442 Controls the passing of target specific information to the disassembler.
443 If it is necessary to specify more than one disassembler option then
444 multiple options can be placed together into a comma separated list.
445 The default value is the empty string. Currently, the only supported
446 targets are ARM, PowerPC and S/390.
451 Erases all the flash memory regions reported by the target. This is
452 equivalent to the CLI command flash-erase.
454 -file-list-shared-libraries
455 List the shared libraries in the program. This is
456 equivalent to the CLI command "info shared".
459 Catchpoints stopping the program when Ada exceptions are
460 handled. This is equivalent to the CLI command "catch handlers".
462 *** Changes in GDB 7.12
464 * GDB and GDBserver now build with a C++ compiler by default.
466 The --enable-build-with-cxx configure option is now enabled by
467 default. One must now explicitly configure with
468 --disable-build-with-cxx in order to build with a C compiler. This
469 option will be removed in a future release.
471 * GDBserver now supports recording btrace without maintaining an active
474 * GDB now supports a negative repeat count in the 'x' command to examine
475 memory backward from the given address. For example:
478 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
479 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
480 (gdb) x/-5i 0x0000000000400580
481 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
482 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
483 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
484 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
485 0x40057b <main(int, char**)+25>:
486 callq 0x400536 <Func1(int, char const*)>
488 * Fortran: Support structures with fields of dynamic types and
489 arrays of dynamic types.
491 * The symbol dumping maintenance commands have new syntax.
492 maint print symbols [-pc address] [--] [filename]
493 maint print symbols [-objfile objfile] [-source source] [--] [filename]
494 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
495 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
496 maint print msymbols [-objfile objfile] [--] [filename]
498 * GDB now supports multibit bitfields and enums in target register
501 * New Python-based convenience function $_as_string(val), which returns
502 the textual representation of a value. This function is especially
503 useful to obtain the text label of an enum value.
505 * Intel MPX bound violation handling.
507 Segmentation faults caused by a Intel MPX boundary violation
508 now display the kind of violation (upper or lower), the memory
509 address accessed and the memory bounds, along with the usual
510 signal received and code location.
514 Program received signal SIGSEGV, Segmentation fault
515 Upper bound violation while accessing address 0x7fffffffc3b3
516 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
517 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
519 * Rust language support.
520 GDB now supports debugging programs written in the Rust programming
521 language. See https://www.rust-lang.org/ for more information about
524 * Support for running interpreters on specified input/output devices
526 GDB now supports a new mechanism that allows frontends to provide
527 fully featured GDB console views, as a better alternative to
528 building such views on top of the "-interpreter-exec console"
529 command. See the new "new-ui" command below. With that command,
530 frontends can now start GDB in the traditional command-line mode
531 running in an embedded terminal emulator widget, and create a
532 separate MI interpreter running on a specified i/o device. In this
533 way, GDB handles line editing, history, tab completion, etc. in the
534 console all by itself, and the GUI uses the separate MI interpreter
535 for its own control and synchronization, invisible to the command
538 * The "catch syscall" command catches groups of related syscalls.
540 The "catch syscall" command now supports catching a group of related
541 syscalls using the 'group:' or 'g:' prefix.
546 skip -gfile file-glob-pattern
547 skip -function function
548 skip -rfunction regular-expression
549 A generalized form of the skip command, with new support for
550 glob-style file names and regular expressions for function names.
551 Additionally, a file spec and a function spec may now be combined.
553 maint info line-table REGEXP
554 Display the contents of GDB's internal line table data struture.
557 Run any GDB unit tests that were compiled in.
560 Start a new user interface instance running INTERP as interpreter,
561 using the TTY file for input/output.
565 ** gdb.Breakpoint objects have a new attribute "pending", which
566 indicates whether the breakpoint is pending.
567 ** Three new breakpoint-related events have been added:
568 gdb.breakpoint_created, gdb.breakpoint_modified, and
569 gdb.breakpoint_deleted.
572 Signal ("set") the given MS-Windows event object. This is used in
573 conjunction with the Windows JIT debugging (AeDebug) support, where
574 the OS suspends a crashing process until a debugger can attach to
575 it. Resuming the crashing process, in order to debug it, is done by
578 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
579 was added in GDBserver, including JIT compiling fast tracepoint's
580 conditional expression bytecode into native code.
582 * Support for various remote target protocols and ROM monitors has
585 target m32rsdi Remote M32R debugging over SDI
586 target mips MIPS remote debugging protocol
587 target pmon PMON ROM monitor
588 target ddb NEC's DDB variant of PMON for Vr4300
589 target rockhopper NEC RockHopper variant of PMON
590 target lsi LSI variant of PMO
592 * Support for tracepoints and fast tracepoints on powerpc-linux,
593 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
594 including JIT compiling fast tracepoint's conditional expression
595 bytecode into native code.
597 * MI async record =record-started now includes the method and format used for
598 recording. For example:
600 =record-started,thread-group="i1",method="btrace",format="bts"
602 * MI async record =thread-selected now includes the frame field. For example:
604 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
608 Andes NDS32 nds32*-*-elf
610 *** Changes in GDB 7.11
612 * GDB now supports debugging kernel-based threads on FreeBSD.
614 * Per-inferior thread numbers
616 Thread numbers are now per inferior instead of global. If you're
617 debugging multiple inferiors, GDB displays thread IDs using a
618 qualified INF_NUM.THR_NUM form. For example:
622 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
623 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
624 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
625 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
627 As consequence, thread numbers as visible in the $_thread
628 convenience variable and in Python's InferiorThread.num attribute
629 are no longer unique between inferiors.
631 GDB now maintains a second thread ID per thread, referred to as the
632 global thread ID, which is the new equivalent of thread numbers in
633 previous releases. See also $_gthread below.
635 For backwards compatibility, MI's thread IDs always refer to global
638 * Commands that accept thread IDs now accept the qualified
639 INF_NUM.THR_NUM form as well. For example:
642 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
645 * In commands that accept a list of thread IDs, you can now refer to
646 all threads of an inferior using a star wildcard. GDB accepts
647 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
648 refer to all threads of the current inferior. For example, "info
651 * You can use "info threads -gid" to display the global thread ID of
654 * The new convenience variable $_gthread holds the global number of
657 * The new convenience variable $_inferior holds the number of the
660 * GDB now displays the ID and name of the thread that hit a breakpoint
661 or received a signal, if your program is multi-threaded. For
664 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
665 Thread 1 "main" received signal SIGINT, Interrupt.
667 * Record btrace now supports non-stop mode.
669 * Support for tracepoints on aarch64-linux was added in GDBserver.
671 * The 'record instruction-history' command now indicates speculative execution
672 when using the Intel Processor Trace recording format.
674 * GDB now allows users to specify explicit locations, bypassing
675 the linespec parser. This feature is also available to GDB/MI
678 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
679 GDB now is able to debug both AArch64 applications and ARM applications
682 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
683 including JIT compiling fast tracepoint's conditional expression bytecode
686 * GDB now supports displaced stepping on AArch64 GNU/Linux.
688 * "info threads", "info inferiors", "info display", "info checkpoints"
689 and "maint info program-spaces" now list the corresponding items in
690 ascending ID order, for consistency with all other "info" commands.
692 * In Ada, the overloads selection menu has been enhanced to display the
693 parameter types and the return types for the matching overloaded subprograms.
697 maint set target-non-stop (on|off|auto)
698 maint show target-non-stop
699 Control whether GDB targets always operate in non-stop mode even if
700 "set non-stop" is "off". The default is "auto", meaning non-stop
701 mode is enabled if supported by the target.
703 maint set bfd-sharing
704 maint show bfd-sharing
705 Control the reuse of bfd objects.
709 Control display of debugging info regarding bfd caching.
713 Control display of debugging info regarding FreeBSD threads.
715 set remote multiprocess-extensions-packet
716 show remote multiprocess-extensions-packet
717 Set/show the use of the remote protocol multiprocess extensions.
719 set remote thread-events
720 show remote thread-events
721 Set/show the use of thread create/exit events.
723 set ada print-signatures on|off
724 show ada print-signatures"
725 Control whether parameter types and return types are displayed in overloads
726 selection menus. It is activaled (@code{on}) by default.
730 Controls the maximum size of memory, in bytes, that GDB will
731 allocate for value contents. Prevents incorrect programs from
732 causing GDB to allocate overly large buffers. Default is 64k.
734 * The "disassemble" command accepts a new modifier: /s.
735 It prints mixed source+disassembly like /m with two differences:
736 - disassembled instructions are now printed in program order, and
737 - and source for all relevant files is now printed.
738 The "/m" option is now considered deprecated: its "source-centric"
739 output hasn't proved useful in practice.
741 * The "record instruction-history" command accepts a new modifier: /s.
742 It behaves exactly like /m and prints mixed source+disassembly.
744 * The "set scheduler-locking" command supports a new mode "replay".
745 It behaves like "off" in record mode and like "on" in replay mode.
747 * Support for various ROM monitors has been removed:
749 target dbug dBUG ROM monitor for Motorola ColdFire
750 target picobug Motorola picobug monitor
751 target dink32 DINK32 ROM monitor for PowerPC
752 target m32r Renesas M32R/D ROM monitor
753 target mon2000 mon2000 ROM monitor
754 target ppcbug PPCBUG ROM monitor for PowerPC
756 * Support for reading/writing memory and extracting values on architectures
757 whose memory is addressable in units of any integral multiple of 8 bits.
760 Allows to break when an Ada exception is handled.
765 Indicates that an exec system call was executed.
767 exec-events feature in qSupported
768 The qSupported packet allows GDB to request support for exec
769 events using the new 'gdbfeature' exec-event, and the qSupported
770 response can contain the corresponding 'stubfeature'. Set and
771 show commands can be used to display whether these features are enabled.
774 Equivalent to interrupting with the ^C character, but works in
777 thread created stop reason (T05 create:...)
778 Indicates that the thread was just created and is stopped at entry.
780 thread exit stop reply (w exitcode;tid)
781 Indicates that the thread has terminated.
784 Enables/disables thread create and exit event reporting. For
785 example, this is used in non-stop mode when GDB stops a set of
786 threads and synchronously waits for the their corresponding stop
787 replies. Without exit events, if one of the threads exits, GDB
788 would hang forever not knowing that it should no longer expect a
789 stop for that same thread.
792 Indicates that there are no resumed threads left in the target (all
793 threads are stopped). The remote stub reports support for this stop
794 reply to GDB's qSupported query.
797 Enables/disables catching syscalls from the inferior process.
798 The remote stub reports support for this packet to GDB's qSupported query.
800 syscall_entry stop reason
801 Indicates that a syscall was just called.
803 syscall_return stop reason
804 Indicates that a syscall just returned.
806 * Extended-remote exec events
808 ** GDB now has support for exec events on extended-remote Linux targets.
809 For such targets with Linux kernels 2.5.46 and later, this enables
810 follow-exec-mode and exec catchpoints.
812 set remote exec-event-feature-packet
813 show remote exec-event-feature-packet
814 Set/show the use of the remote exec event feature.
816 * Thread names in remote protocol
818 The reply to qXfer:threads:read may now include a name attribute for each
821 * Target remote mode fork and exec events
823 ** GDB now has support for fork and exec events on target remote mode
824 Linux targets. For such targets with Linux kernels 2.5.46 and later,
825 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
826 fork and exec catchpoints.
828 * Remote syscall events
830 ** GDB now has support for catch syscall on remote Linux targets,
831 currently enabled on x86/x86_64 architectures.
833 set remote catch-syscall-packet
834 show remote catch-syscall-packet
835 Set/show the use of the remote catch syscall feature.
839 ** The -var-set-format command now accepts the zero-hexadecimal
840 format. It outputs data in hexadecimal format with zero-padding on the
845 ** gdb.InferiorThread objects have a new attribute "global_num",
846 which refers to the thread's global thread ID. The existing
847 "num" attribute now refers to the thread's per-inferior number.
848 See "Per-inferior thread numbers" above.
849 ** gdb.InferiorThread objects have a new attribute "inferior", which
850 is the Inferior object the thread belongs to.
852 *** Changes in GDB 7.10
854 * Support for process record-replay and reverse debugging on aarch64*-linux*
855 targets has been added. GDB now supports recording of A64 instruction set
856 including advance SIMD instructions.
858 * Support for Sun's version of the "stabs" debug file format has been removed.
860 * GDB now honors the content of the file /proc/PID/coredump_filter
861 (PID is the process ID) on GNU/Linux systems. This file can be used
862 to specify the types of memory mappings that will be included in a
863 corefile. For more information, please refer to the manual page of
864 "core(5)". GDB also has a new command: "set use-coredump-filter
865 on|off". It allows to set whether GDB will read the content of the
866 /proc/PID/coredump_filter file when generating a corefile.
868 * The "info os" command on GNU/Linux can now display information on
870 "info os cpus" Listing of all cpus/cores on the system
872 * GDB has two new commands: "set serial parity odd|even|none" and
873 "show serial parity". These allows to set or show parity for the
876 * The "info source" command now displays the producer string if it was
877 present in the debug info. This typically includes the compiler version
878 and may include things like its command line arguments.
880 * The "info dll", an alias of the "info sharedlibrary" command,
881 is now available on all platforms.
883 * Directory names supplied to the "set sysroot" commands may be
884 prefixed with "target:" to tell GDB to access shared libraries from
885 the target system, be it local or remote. This replaces the prefix
886 "remote:". The default sysroot has been changed from "" to
887 "target:". "remote:" is automatically converted to "target:" for
888 backward compatibility.
890 * The system root specified by "set sysroot" will be prepended to the
891 filename of the main executable (if reported to GDB as absolute by
892 the operating system) when starting processes remotely, and when
893 attaching to already-running local or remote processes.
895 * GDB now supports automatic location and retrieval of executable
896 files from remote targets. Remote debugging can now be initiated
897 using only a "target remote" or "target extended-remote" command
898 (no "set sysroot" or "file" commands are required). See "New remote
901 * The "dump" command now supports verilog hex format.
903 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
905 * On GNU/Linux, GDB and gdbserver are now able to access executable
906 and shared library files without a "set sysroot" command when
907 attaching to processes running in different mount namespaces from
908 the debugger. This makes it possible to attach to processes in
909 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
910 See "New remote packets" below.
912 * The "tui reg" command now provides completion for all of the
913 available register groups, including target specific groups.
915 * The HISTSIZE environment variable is no longer read when determining
916 the size of GDB's command history. GDB now instead reads the dedicated
917 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
918 disables truncation of command history. Non-numeric values of GDBHISTSIZE
923 ** Memory ports can now be unbuffered.
927 ** gdb.Objfile objects have a new attribute "username",
928 which is the name of the objfile as specified by the user,
929 without, for example, resolving symlinks.
930 ** You can now write frame unwinders in Python.
931 ** gdb.Type objects have a new method "optimized_out",
932 returning optimized out gdb.Value instance of this type.
933 ** gdb.Value objects have new methods "reference_value" and
934 "const_value" which return a reference to the value and a
935 "const" version of the value respectively.
939 maint print symbol-cache
940 Print the contents of the symbol cache.
942 maint print symbol-cache-statistics
943 Print statistics of symbol cache usage.
945 maint flush-symbol-cache
946 Flush the contents of the symbol cache.
950 Start branch trace recording using Branch Trace Store (BTS) format.
953 Evaluate expression by using the compiler and print result.
957 Explicit commands for enabling and disabling tui mode.
960 set mpx bound on i386 and amd64
961 Support for bound table investigation on Intel MPX enabled applications.
965 Start branch trace recording using Intel Processor Trace format.
968 Print information about branch tracing internals.
970 maint btrace packet-history
971 Print the raw branch tracing data.
973 maint btrace clear-packet-history
974 Discard the stored raw branch tracing data.
977 Discard all branch tracing data. It will be fetched and processed
978 anew by the next "record" command.
983 Renamed from "set debug dwarf2-die".
985 Renamed from "show debug dwarf2-die".
988 Renamed from "set debug dwarf2-read".
989 show debug dwarf-read
990 Renamed from "show debug dwarf2-read".
992 maint set dwarf always-disassemble
993 Renamed from "maint set dwarf2 always-disassemble".
994 maint show dwarf always-disassemble
995 Renamed from "maint show dwarf2 always-disassemble".
997 maint set dwarf max-cache-age
998 Renamed from "maint set dwarf2 max-cache-age".
999 maint show dwarf max-cache-age
1000 Renamed from "maint show dwarf2 max-cache-age".
1002 set debug dwarf-line
1003 show debug dwarf-line
1004 Control display of debugging info regarding DWARF line processing.
1007 show max-completions
1008 Set the maximum number of candidates to be considered during
1009 completion. The default value is 200. This limit allows GDB
1010 to avoid generating large completion lists, the computation of
1011 which can cause the debugger to become temporarily unresponsive.
1013 set history remove-duplicates
1014 show history remove-duplicates
1015 Control the removal of duplicate history entries.
1017 maint set symbol-cache-size
1018 maint show symbol-cache-size
1019 Control the size of the symbol cache.
1021 set|show record btrace bts buffer-size
1022 Set and show the size of the ring buffer used for branch tracing in
1024 The obtained size may differ from the requested size. Use "info
1025 record" to see the obtained buffer size.
1027 set debug linux-namespaces
1028 show debug linux-namespaces
1029 Control display of debugging info regarding Linux namespaces.
1031 set|show record btrace pt buffer-size
1032 Set and show the size of the ring buffer used for branch tracing in
1033 Intel Processor Trace format.
1034 The obtained size may differ from the requested size. Use "info
1035 record" to see the obtained buffer size.
1037 maint set|show btrace pt skip-pad
1038 Set and show whether PAD packets are skipped when computing the
1041 * The command 'thread apply all' can now support new option '-ascending'
1042 to call its specified command for all threads in ascending order.
1044 * Python/Guile scripting
1046 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1047 special section named `.debug_gdb_scripts'.
1049 * New remote packets
1051 qXfer:btrace-conf:read
1052 Return the branch trace configuration for the current thread.
1054 Qbtrace-conf:bts:size
1055 Set the requested ring buffer size for branch tracing in BTS format.
1058 Enable Intel Procesor Trace-based branch tracing for the current
1059 process. The remote stub reports support for this packet to GDB's
1062 Qbtrace-conf:pt:size
1063 Set the requested ring buffer size for branch tracing in Intel Processor
1067 Indicates a memory breakpoint instruction was executed, irrespective
1068 of whether it was GDB that planted the breakpoint or the breakpoint
1069 is hardcoded in the program. This is required for correct non-stop
1073 Indicates the target stopped for a hardware breakpoint. This is
1074 required for correct non-stop mode operation.
1077 Return information about files on the remote system.
1079 qXfer:exec-file:read
1080 Return the full absolute name of the file that was executed to
1081 create a process running on the remote system.
1084 Select the filesystem on which vFile: operations with filename
1085 arguments will operate. This is required for GDB to be able to
1086 access files on remote targets where the remote stub does not
1087 share a common filesystem with the inferior(s).
1090 Indicates that a fork system call was executed.
1093 Indicates that a vfork system call was executed.
1095 vforkdone stop reason
1096 Indicates that a vfork child of the specified process has executed
1097 an exec or exit, allowing the vfork parent to resume execution.
1099 fork-events and vfork-events features in qSupported
1100 The qSupported packet allows GDB to request support for fork and
1101 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1102 and the qSupported response can contain the corresponding
1103 'stubfeatures'. Set and show commands can be used to display
1104 whether these features are enabled.
1106 * Extended-remote fork events
1108 ** GDB now has support for fork events on extended-remote Linux
1109 targets. For targets with Linux kernels 2.5.60 and later, this
1110 enables follow-fork-mode and detach-on-fork for both fork and
1111 vfork, as well as fork and vfork catchpoints.
1113 * The info record command now shows the recording format and the
1114 branch tracing configuration for the current thread when using
1115 the btrace record target.
1116 For the BTS format, it shows the ring buffer size.
1118 * GDB now has support for DTrace USDT (Userland Static Defined
1119 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1121 * GDB now supports access to vector registers on S/390 GNU/Linux
1124 * Removed command line options
1126 -xdb HP-UX XDB compatibility mode.
1128 * Removed targets and native configurations
1130 HP/PA running HP-UX hppa*-*-hpux*
1131 Itanium running HP-UX ia64-*-hpux*
1133 * New configure options
1136 This configure option allows the user to build GDB with support for
1137 Intel Processor Trace (default: auto). This requires libipt.
1139 --with-libipt-prefix=PATH
1140 Specify the path to the version of libipt that GDB should use.
1141 $PATH/include should contain the intel-pt.h header and
1142 $PATH/lib should contain the libipt.so library.
1144 *** Changes in GDB 7.9.1
1148 ** Xmethods can now specify a result type.
1150 *** Changes in GDB 7.9
1152 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1156 ** You can now access frame registers from Python scripts.
1157 ** New attribute 'producer' for gdb.Symtab objects.
1158 ** gdb.Objfile objects have a new attribute "progspace",
1159 which is the gdb.Progspace object of the containing program space.
1160 ** gdb.Objfile objects have a new attribute "owner".
1161 ** gdb.Objfile objects have a new attribute "build_id",
1162 which is the build ID generated when the file was built.
1163 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1164 ** A new event "gdb.clear_objfiles" has been added, triggered when
1165 selecting a new file to debug.
1166 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1167 ** New function gdb.lookup_objfile.
1169 New events which are triggered when GDB modifies the state of the
1172 ** gdb.events.inferior_call_pre: Function call is about to be made.
1173 ** gdb.events.inferior_call_post: Function call has just been made.
1174 ** gdb.events.memory_changed: A memory location has been altered.
1175 ** gdb.events.register_changed: A register has been altered.
1177 * New Python-based convenience functions:
1179 ** $_caller_is(name [, number_of_frames])
1180 ** $_caller_matches(regexp [, number_of_frames])
1181 ** $_any_caller_is(name [, number_of_frames])
1182 ** $_any_caller_matches(regexp [, number_of_frames])
1184 * GDB now supports the compilation and injection of source code into
1185 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1186 to compile the source code to object code, and if successful, inject
1187 and execute that code within the current context of the inferior.
1188 Currently the C language is supported. The commands used to
1189 interface with this new feature are:
1191 compile code [-raw|-r] [--] [source code]
1192 compile file [-raw|-r] filename
1196 demangle [-l language] [--] name
1197 Demangle "name" in the specified language, or the current language
1198 if elided. This command is renamed from the "maint demangle" command.
1199 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1200 as "maint demangler-warning".
1202 queue-signal signal-name-or-number
1203 Queue a signal to be delivered to the thread when it is resumed.
1205 add-auto-load-scripts-directory directory
1206 Add entries to the list of directories from which to load auto-loaded
1209 maint print user-registers
1210 List all currently available "user" registers.
1212 compile code [-r|-raw] [--] [source code]
1213 Compile, inject, and execute in the inferior the executable object
1214 code produced by compiling the provided source code.
1216 compile file [-r|-raw] filename
1217 Compile and inject into the inferior the executable object code
1218 produced by compiling the source code stored in the filename
1221 * On resume, GDB now always passes the signal the program had stopped
1222 for to the thread the signal was sent to, even if the user changed
1223 threads before resuming. Previously GDB would often (but not
1224 always) deliver the signal to the thread that happens to be current
1227 * Conversely, the "signal" command now consistently delivers the
1228 requested signal to the current thread. GDB now asks for
1229 confirmation if the program had stopped for a signal and the user
1230 switched threads meanwhile.
1232 * "breakpoint always-inserted" modes "off" and "auto" merged.
1234 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1235 won't remove breakpoints from the target until all threads stop,
1236 even in non-stop mode. The "auto" mode has been removed, and "off"
1237 is now the default mode.
1241 set debug symbol-lookup
1242 show debug symbol-lookup
1243 Control display of debugging info regarding symbol lookup.
1247 ** The -list-thread-groups command outputs an exit-code field for
1248 inferiors that have exited.
1252 MIPS SDE mips*-sde*-elf*
1256 Support for these obsolete configurations has been removed.
1258 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1259 SGI Irix-5.x mips-*-irix5*
1260 SGI Irix-6.x mips-*-irix6*
1261 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1262 VAX running Ultrix vax-*-ultrix*
1264 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1265 and "assf"), have been removed. Use the "sharedlibrary" command, or
1266 its alias "share", instead.
1268 *** Changes in GDB 7.8
1270 * New command line options
1273 This is an alias for the --data-directory option.
1275 * GDB supports printing and modifying of variable length automatic arrays
1276 as specified in ISO C99.
1278 * The ARM simulator now supports instruction level tracing
1279 with or without disassembly.
1283 GDB now has support for scripting using Guile. Whether this is
1284 available is determined at configure time.
1285 Guile version 2.0 or greater is required.
1286 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1288 * New commands (for set/show, see "New options" below)
1292 Invoke CODE by passing it to the Guile interpreter.
1296 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1298 info auto-load guile-scripts [regexp]
1299 Print the list of automatically loaded Guile scripts.
1301 * The source command is now capable of sourcing Guile scripts.
1302 This feature is dependent on the debugger being built with Guile support.
1306 set print symbol-loading (off|brief|full)
1307 show print symbol-loading
1308 Control whether to print informational messages when loading symbol
1309 information for a file. The default is "full", but when debugging
1310 programs with large numbers of shared libraries the amount of output
1311 becomes less useful.
1313 set guile print-stack (none|message|full)
1314 show guile print-stack
1315 Show a stack trace when an error is encountered in a Guile script.
1317 set auto-load guile-scripts (on|off)
1318 show auto-load guile-scripts
1319 Control auto-loading of Guile script files.
1321 maint ada set ignore-descriptive-types (on|off)
1322 maint ada show ignore-descriptive-types
1323 Control whether the debugger should ignore descriptive types in Ada
1324 programs. The default is not to ignore the descriptive types. See
1325 the user manual for more details on descriptive types and the intended
1326 usage of this option.
1328 set auto-connect-native-target
1330 Control whether GDB is allowed to automatically connect to the
1331 native target for the run, attach, etc. commands when not connected
1332 to any target yet. See also "target native" below.
1334 set record btrace replay-memory-access (read-only|read-write)
1335 show record btrace replay-memory-access
1336 Control what memory accesses are allowed during replay.
1338 maint set target-async (on|off)
1339 maint show target-async
1340 This controls whether GDB targets operate in synchronous or
1341 asynchronous mode. Normally the default is asynchronous, if it is
1342 available; but this can be changed to more easily debug problems
1343 occurring only in synchronous mode.
1345 set mi-async (on|off)
1347 Control whether MI asynchronous mode is preferred. This supersedes
1348 "set target-async" of previous GDB versions.
1350 * "set target-async" is deprecated as a CLI option and is now an alias
1351 for "set mi-async" (only puts MI into async mode).
1353 * Background execution commands (e.g., "c&", "s&", etc.) are now
1354 possible ``out of the box'' if the target supports them. Previously
1355 the user would need to explicitly enable the possibility with the
1356 "set target-async on" command.
1358 * New features in the GDB remote stub, GDBserver
1360 ** New option --debug-format=option1[,option2,...] allows one to add
1361 additional text to each output. At present only timestamps
1362 are supported: --debug-format=timestamps.
1363 Timestamps can also be turned on with the
1364 "monitor set debug-format timestamps" command from GDB.
1366 * The 'record instruction-history' command now starts counting instructions
1367 at one. This also affects the instruction ranges reported by the
1368 'record function-call-history' command when given the /i modifier.
1370 * The command 'record function-call-history' supports a new modifier '/c' to
1371 indent the function names based on their call stack depth.
1372 The fields for the '/i' and '/l' modifier have been reordered.
1373 The source line range is now prefixed with 'at'.
1374 The instruction range is now prefixed with 'inst'.
1375 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1376 "record instruction-history" and "list" commands.
1378 * The ranges given as arguments to the 'record function-call-history' and
1379 'record instruction-history' commands are now inclusive.
1381 * The btrace record target now supports the 'record goto' command.
1382 For locations inside the execution trace, the back trace is computed
1383 based on the information stored in the execution trace.
1385 * The btrace record target supports limited reverse execution and replay.
1386 The target does not record data and therefore does not allow reading
1387 memory or registers.
1389 * The "catch syscall" command now works on s390*-linux* targets.
1391 * The "compare-sections" command is no longer specific to target
1392 remote. It now works with all targets.
1394 * All native targets are now consistently called "native".
1395 Consequently, the "target child", "target GNU", "target djgpp",
1396 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1397 commands have been replaced with "target native". The QNX/NTO port
1398 leaves the "procfs" target in place and adds a "native" target for
1399 consistency with other ports. The impact on users should be minimal
1400 as these commands previously either throwed an error, or were
1401 no-ops. The target's name is visible in the output of the following
1402 commands: "help target", "info target", "info files", "maint print
1405 * The "target native" command now connects to the native target. This
1406 can be used to launch native programs even when "set
1407 auto-connect-native-target" is set to off.
1409 * GDB now supports access to Intel MPX registers on GNU/Linux.
1411 * Support for Intel AVX-512 registers on GNU/Linux.
1412 Support displaying and modifying Intel AVX-512 registers
1413 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1415 * New remote packets
1417 qXfer:btrace:read's annex
1418 The qXfer:btrace:read packet supports a new annex 'delta' to read
1419 branch trace incrementally.
1423 ** Valid Python operations on gdb.Value objects representing
1424 structs/classes invoke the corresponding overloaded operators if
1426 ** New `Xmethods' feature in the Python API. Xmethods are
1427 additional methods or replacements for existing methods of a C++
1428 class. This feature is useful for those cases where a method
1429 defined in C++ source code could be inlined or optimized out by
1430 the compiler, making it unavailable to GDB.
1433 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1435 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1436 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1437 its alias "share", instead.
1439 * The commands "set remotebaud" and "show remotebaud" are no longer
1440 supported. Use "set serial baud" and "show serial baud" (respectively)
1445 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1446 target-async". The latter is left as a deprecated alias of the
1447 former for backward compatibility. If the target supports it,
1448 CLI background execution commands are now always possible by
1449 default, independently of whether the frontend stated a
1450 preference for asynchronous execution with "-gdb-set mi-async".
1451 Previously "-gdb-set target-async off" affected both MI execution
1452 commands and CLI execution commands.
1454 *** Changes in GDB 7.7
1456 * Improved support for process record-replay and reverse debugging on
1457 arm*-linux* targets. Support for thumb32 and syscall instruction
1458 recording has been added.
1460 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1462 * GDB now supports Fission DWP file format version 2.
1463 http://gcc.gnu.org/wiki/DebugFission
1465 * New convenience function "$_isvoid", to check whether an expression
1466 is void. A void expression is an expression where the type of the
1467 result is "void". For example, some convenience variables may be
1468 "void" when evaluated (e.g., "$_exitcode" before the execution of
1469 the program being debugged; or an undefined convenience variable).
1470 Another example, when calling a function whose return type is
1473 * The "maintenance print objfiles" command now takes an optional regexp.
1475 * The "catch syscall" command now works on arm*-linux* targets.
1477 * GDB now consistently shows "<not saved>" when printing values of
1478 registers the debug info indicates have not been saved in the frame
1479 and there's nowhere to retrieve them from
1480 (callee-saved/call-clobbered registers):
1485 (gdb) info registers rax
1488 Before, the former would print "<optimized out>", and the latter
1489 "*value not available*".
1491 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1496 ** Frame filters and frame decorators have been added.
1497 ** Temporary breakpoints are now supported.
1498 ** Line tables representation has been added.
1499 ** New attribute 'parent_type' for gdb.Field objects.
1500 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1501 ** New attribute 'name' for gdb.Type objects.
1505 Nios II ELF nios2*-*-elf
1506 Nios II GNU/Linux nios2*-*-linux
1507 Texas Instruments MSP430 msp430*-*-elf
1509 * Removed native configurations
1511 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1512 been removed. ELF variants of these configurations are kept supported.
1514 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1515 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1516 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1517 i[34567]86-*-openbsd3.[0-3]
1518 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1519 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1520 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1524 Like "catch throw", but catches a re-thrown exception.
1525 maint check-psymtabs
1526 Renamed from old "maint check-symtabs".
1528 Perform consistency checks on symtabs.
1529 maint expand-symtabs
1530 Expand symtabs matching an optional regexp.
1533 Display the details of GDB configure-time options.
1535 maint set|show per-command
1536 maint set|show per-command space
1537 maint set|show per-command time
1538 maint set|show per-command symtab
1539 Enable display of per-command gdb resource usage.
1541 remove-symbol-file FILENAME
1542 remove-symbol-file -a ADDRESS
1543 Remove a symbol file added via add-symbol-file. The file to remove
1544 can be identified by its filename or by an address that lies within
1545 the boundaries of this symbol file in memory.
1548 info exceptions REGEXP
1549 Display the list of Ada exceptions defined in the program being
1550 debugged. If provided, only the exceptions whose names match REGEXP
1555 set debug symfile off|on
1557 Control display of debugging info regarding reading symbol files and
1558 symbol tables within those files
1560 set print raw frame-arguments
1561 show print raw frame-arguments
1562 Set/show whether to print frame arguments in raw mode,
1563 disregarding any defined pretty-printers.
1565 set remote trace-status-packet
1566 show remote trace-status-packet
1567 Set/show the use of remote protocol qTStatus packet.
1571 Control display of debugging messages related to Nios II targets.
1575 Control whether target-assisted range stepping is enabled.
1577 set startup-with-shell
1578 show startup-with-shell
1579 Specifies whether Unix child processes are started via a shell or
1584 Use the target memory cache for accesses to the code segment. This
1585 improves performance of remote debugging (particularly disassembly).
1587 * You can now use a literal value 'unlimited' for options that
1588 interpret 0 or -1 as meaning "unlimited". E.g., "set
1589 trace-buffer-size unlimited" is now an alias for "set
1590 trace-buffer-size -1" and "set height unlimited" is now an alias for
1593 * The "set debug symtab-create" debugging option of GDB has been changed to
1594 accept a verbosity level. 0 means "off", 1 provides basic debugging
1595 output, and values of 2 or greater provides more verbose output.
1597 * New command-line options
1599 Display the details of GDB configure-time options.
1601 * The command 'tsave' can now support new option '-ctf' to save trace
1602 buffer in Common Trace Format.
1604 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1607 * GDB now implements the the C++ 'typeid' operator.
1609 * The new convenience variable $_exception holds the exception being
1610 thrown or caught at an exception-related catchpoint.
1612 * The exception-related catchpoints, like "catch throw", now accept a
1613 regular expression which can be used to filter exceptions by type.
1615 * The new convenience variable $_exitsignal is automatically set to
1616 the terminating signal number when the program being debugged dies
1617 due to an uncaught signal.
1621 ** All MI commands now accept an optional "--language" option.
1622 Support for this feature can be verified by using the "-list-features"
1623 command, which should contain "language-option".
1625 ** The new command -info-gdb-mi-command allows the user to determine
1626 whether a GDB/MI command is supported or not.
1628 ** The "^error" result record returned when trying to execute an undefined
1629 GDB/MI command now provides a variable named "code" whose content is the
1630 "undefined-command" error code. Support for this feature can be verified
1631 by using the "-list-features" command, which should contain
1632 "undefined-command-error-code".
1634 ** The -trace-save MI command can optionally save trace buffer in Common
1637 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1639 ** The command -data-list-register-values now accepts an optional
1640 "--skip-unavailable" option. When used, only the available registers
1643 ** The new command -trace-frame-collected dumps collected variables,
1644 computed expressions, tvars, memory and registers in a traceframe.
1646 ** The commands -stack-list-locals, -stack-list-arguments and
1647 -stack-list-variables now accept an option "--skip-unavailable".
1648 When used, only the available locals or arguments are displayed.
1650 ** The -exec-run command now accepts an optional "--start" option.
1651 When used, the command follows the same semantics as the "start"
1652 command, stopping the program's execution at the start of its
1653 main subprogram. Support for this feature can be verified using
1654 the "-list-features" command, which should contain
1655 "exec-run-start-option".
1657 ** The new commands -catch-assert and -catch-exceptions insert
1658 catchpoints stopping the program when Ada exceptions are raised.
1660 ** The new command -info-ada-exceptions provides the equivalent of
1661 the new "info exceptions" command.
1663 * New system-wide configuration scripts
1664 A GDB installation now provides scripts suitable for use as system-wide
1665 configuration scripts for the following systems:
1669 * GDB now supports target-assigned range stepping with remote targets.
1670 This improves the performance of stepping source lines by reducing
1671 the number of control packets from/to GDB. See "New remote packets"
1674 * GDB now understands the element 'tvar' in the XML traceframe info.
1675 It has the id of the collected trace state variables.
1677 * On S/390 targets that provide the transactional-execution feature,
1678 the program interruption transaction diagnostic block (TDB) is now
1679 represented as a number of additional "registers" in GDB.
1681 * New remote packets
1685 The vCont packet supports a new 'r' action, that tells the remote
1686 stub to step through an address range itself, without GDB
1687 involvemement at each single-step.
1689 qXfer:libraries-svr4:read's annex
1690 The previously unused annex of the qXfer:libraries-svr4:read packet
1691 is now used to support passing an argument list. The remote stub
1692 reports support for this argument list to GDB's qSupported query.
1693 The defined arguments are "start" and "prev", used to reduce work
1694 necessary for library list updating, resulting in significant
1697 * New features in the GDB remote stub, GDBserver
1699 ** GDBserver now supports target-assisted range stepping. Currently
1700 enabled on x86/x86_64 GNU/Linux targets.
1702 ** GDBserver now adds element 'tvar' in the XML in the reply to
1703 'qXfer:traceframe-info:read'. It has the id of the collected
1704 trace state variables.
1706 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1709 * New 'z' formatter for printing and examining memory, this displays the
1710 value as hexadecimal zero padded on the left to the size of the type.
1712 * GDB can now use Windows x64 unwinding data.
1714 * The "set remotebaud" command has been replaced by "set serial baud".
1715 Similarly, "show remotebaud" has been replaced by "show serial baud".
1716 The "set remotebaud" and "show remotebaud" commands are still available
1717 to provide backward compatibility with older versions of GDB.
1719 *** Changes in GDB 7.6
1721 * Target record has been renamed to record-full.
1722 Record/replay is now enabled with the "record full" command.
1723 This also affects settings that are associated with full record/replay
1724 that have been moved from "set/show record" to "set/show record full":
1726 set|show record full insn-number-max
1727 set|show record full stop-at-limit
1728 set|show record full memory-query
1730 * A new record target "record-btrace" has been added. The new target
1731 uses hardware support to record the control-flow of a process. It
1732 does not support replaying the execution, but it implements the
1733 below new commands for investigating the recorded execution log.
1734 This new recording method can be enabled using:
1738 The "record-btrace" target is only available on Intel Atom processors
1739 and requires a Linux kernel 2.6.32 or later.
1741 * Two new commands have been added for record/replay to give information
1742 about the recorded execution without having to replay the execution.
1743 The commands are only supported by "record btrace".
1745 record instruction-history prints the execution history at
1746 instruction granularity
1748 record function-call-history prints the execution history at
1749 function granularity
1751 * New native configurations
1753 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1754 FreeBSD/powerpc powerpc*-*-freebsd
1755 x86_64/Cygwin x86_64-*-cygwin*
1756 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1760 ARM AArch64 aarch64*-*-elf
1761 ARM AArch64 GNU/Linux aarch64*-*-linux
1762 Lynx 178 PowerPC powerpc-*-lynx*178
1763 x86_64/Cygwin x86_64-*-cygwin*
1764 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1766 * If the configured location of system.gdbinit file (as given by the
1767 --with-system-gdbinit option at configure time) is in the
1768 data-directory (as specified by --with-gdb-datadir at configure
1769 time) or in one of its subdirectories, then GDB will look for the
1770 system-wide init file in the directory specified by the
1771 --data-directory command-line option.
1773 * New command line options:
1775 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1776 other initialization files, unlike -nx which disables all of them.
1778 * Removed command line options
1780 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1783 * The 'ptype' and 'whatis' commands now accept an argument to control
1786 * 'info proc' now works on some core files.
1790 ** Vectors can be created with gdb.Type.vector.
1792 ** Python's atexit.register now works in GDB.
1794 ** Types can be pretty-printed via a Python API.
1796 ** Python 3 is now supported (in addition to Python 2.4 or later)
1798 ** New class gdb.Architecture exposes GDB's internal representation
1799 of architecture in the Python API.
1801 ** New method Frame.architecture returns the gdb.Architecture object
1802 corresponding to the frame's architecture.
1804 * New Python-based convenience functions:
1806 ** $_memeq(buf1, buf2, length)
1807 ** $_streq(str1, str2)
1809 ** $_regex(str, regex)
1811 * The 'cd' command now defaults to using '~' (the home directory) if not
1814 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1815 default for GCC since November 2000.
1817 * The command 'forward-search' can now be abbreviated as 'fo'.
1819 * The command 'info tracepoints' can now display 'installed on target'
1820 or 'not installed on target' for each non-pending location of tracepoint.
1822 * New configure options
1824 --enable-libmcheck/--disable-libmcheck
1825 By default, development versions are built with -lmcheck on hosts
1826 that support it, in order to help track memory corruption issues.
1827 Release versions, on the other hand, are built without -lmcheck
1828 by default. The --enable-libmcheck/--disable-libmcheck configure
1829 options allow the user to override that default.
1830 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1831 This configure option allows the user to build GDB with
1832 libbabeltrace using which GDB can read Common Trace Format data.
1834 * New commands (for set/show, see "New options" below)
1837 Catch signals. This is similar to "handle", but allows commands and
1838 conditions to be attached.
1841 List the BFDs known to GDB.
1843 python-interactive [command]
1845 Start a Python interactive prompt, or evaluate the optional command
1846 and print the result of expressions.
1849 "py" is a new alias for "python".
1851 enable type-printer [name]...
1852 disable type-printer [name]...
1853 Enable or disable type printers.
1857 ** For the Renesas Super-H architecture, the "regs" command has been removed
1858 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1863 set print type methods (on|off)
1864 show print type methods
1865 Control whether method declarations are displayed by "ptype".
1866 The default is to show them.
1868 set print type typedefs (on|off)
1869 show print type typedefs
1870 Control whether typedef definitions are displayed by "ptype".
1871 The default is to show them.
1873 set filename-display basename|relative|absolute
1874 show filename-display
1875 Control the way in which filenames is displayed.
1876 The default is "relative", which preserves previous behavior.
1878 set trace-buffer-size
1879 show trace-buffer-size
1880 Request target to change the size of trace buffer.
1882 set remote trace-buffer-size-packet auto|on|off
1883 show remote trace-buffer-size-packet
1884 Control the use of the remote protocol `QTBuffer:size' packet.
1888 Control display of debugging messages related to ARM AArch64.
1891 set debug coff-pe-read
1892 show debug coff-pe-read
1893 Control display of debugging messages related to reading of COFF/PE
1898 Control display of debugging messages related to Mach-O symbols
1901 set debug notification
1902 show debug notification
1903 Control display of debugging info for async remote notification.
1907 ** Command parameter changes are now notified using new async record
1908 "=cmd-param-changed".
1909 ** Trace frame changes caused by command "tfind" are now notified using
1910 new async record "=traceframe-changed".
1911 ** The creation, deletion and modification of trace state variables
1912 are now notified using new async records "=tsv-created",
1913 "=tsv-deleted" and "=tsv-modified".
1914 ** The start and stop of process record are now notified using new
1915 async record "=record-started" and "=record-stopped".
1916 ** Memory changes are now notified using new async record
1918 ** The data-disassemble command response will include a "fullname" field
1919 containing the absolute file name when source has been requested.
1920 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1921 command, to allow pattern filling of memory areas.
1922 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1923 library load/unload events.
1924 ** The response to breakpoint commands and breakpoint async records
1925 includes an "installed" field containing a boolean state about each
1926 non-pending tracepoint location is whether installed on target or not.
1927 ** Output of the "-trace-status" command includes a "trace-file" field
1928 containing the name of the trace file being examined. This field is
1929 optional, and only present when examining a trace file.
1930 ** The "fullname" field is now always present along with the "file" field,
1931 even if the file cannot be found by GDB.
1933 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1934 You must have the LZMA library available when configuring GDB for this
1935 feature to be enabled. For more information, see:
1936 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1938 * New remote packets
1941 Set the size of trace buffer. The remote stub reports support for this
1942 packet to gdb's qSupported query.
1945 Enable Branch Trace Store (BTS)-based branch tracing for the current
1946 thread. The remote stub reports support for this packet to gdb's
1950 Disable branch tracing for the current thread. The remote stub reports
1951 support for this packet to gdb's qSupported query.
1954 Read the traced branches for the current thread. The remote stub
1955 reports support for this packet to gdb's qSupported query.
1957 *** Changes in GDB 7.5
1959 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1960 for more x32 ABI info.
1962 * GDB now supports access to MIPS DSP registers on Linux targets.
1964 * GDB now supports debugging microMIPS binaries.
1966 * The "info os" command on GNU/Linux can now display information on
1967 several new classes of objects managed by the operating system:
1968 "info os procgroups" lists process groups
1969 "info os files" lists file descriptors
1970 "info os sockets" lists internet-domain sockets
1971 "info os shm" lists shared-memory regions
1972 "info os semaphores" lists semaphores
1973 "info os msg" lists message queues
1974 "info os modules" lists loaded kernel modules
1976 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1977 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1978 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1979 options and inspect the probe arguments using the new $_probe_arg family
1980 of convenience variables. You can obtain more information about SystemTap
1981 in <http://sourceware.org/systemtap/>.
1983 * GDB now supports reversible debugging on ARM, it allows you to
1984 debug basic ARM and THUMB instructions, and provides
1985 record/replay support.
1987 * The option "symbol-reloading" has been deleted as it is no longer used.
1991 ** GDB commands implemented in Python can now be put in command class
1994 ** The "maint set python print-stack on|off" is now deleted.
1996 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1997 apply "flag enum"-style pretty-printing to any enum.
1999 ** gdb.lookup_symbol can now work when there is no current frame.
2001 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2002 the source at which the symbol was defined.
2004 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2005 method 'value'. The former indicates whether the symbol needs a
2006 frame in order to compute its value, and the latter computes the
2009 ** A new method 'referenced_value' on gdb.Value objects which can
2010 dereference pointer as well as C++ reference values.
2012 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2013 which return the global and static blocks (as gdb.Block objects),
2014 of the underlying symbol table, respectively.
2016 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2017 object associated with a PC value.
2019 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2020 of the address range occupied by code for the current source line.
2022 * Go language support.
2023 GDB now supports debugging programs written in the Go programming
2026 * GDBserver now supports stdio connections.
2027 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2029 * The binary "gdbtui" can no longer be built or installed.
2030 Use "gdb -tui" instead.
2032 * GDB will now print "flag" enums specially. A flag enum is one where
2033 all the enumerator values have no bits in common when pairwise
2034 "and"ed. When printing a value whose type is a flag enum, GDB will
2035 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2036 (gdb) print (enum E) 3
2039 * The filename part of a linespec will now match trailing components
2040 of a source file name. For example, "break gcc/expr.c:1000" will
2041 now set a breakpoint in build/gcc/expr.c, but not
2042 build/libcpp/expr.c.
2044 * The "info proc" and "generate-core-file" commands will now also
2045 work on remote targets connected to GDBserver on Linux.
2047 * The command "info catch" has been removed. It has been disabled
2048 since December 2007.
2050 * The "catch exception" and "catch assert" commands now accept
2051 a condition at the end of the command, much like the "break"
2052 command does. For instance:
2054 (gdb) catch exception Constraint_Error if Barrier = True
2056 Previously, it was possible to add a condition to such catchpoints,
2057 but it had to be done as a second step, after the catchpoint had been
2058 created, using the "condition" command.
2060 * The "info static-tracepoint-marker" command will now also work on
2061 native Linux targets with in-process agent.
2063 * GDB can now set breakpoints on inlined functions.
2065 * The .gdb_index section has been updated to include symbols for
2066 inlined functions. GDB will ignore older .gdb_index sections by
2067 default, which could cause symbol files to be loaded more slowly
2068 until their .gdb_index sections can be recreated. The new command
2069 "set use-deprecated-index-sections on" will cause GDB to use any older
2070 .gdb_index sections it finds. This will restore performance, but the
2071 ability to set breakpoints on inlined functions will be lost in symbol
2072 files with older .gdb_index sections.
2074 The .gdb_index section has also been updated to record more information
2075 about each symbol. This speeds up the "info variables", "info functions"
2076 and "info types" commands when used with programs having the .gdb_index
2077 section, as well as speeding up debugging with shared libraries using
2078 the .gdb_index section.
2080 * Ada support for GDB/MI Variable Objects has been added.
2082 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2087 ** New command -info-os is the MI equivalent of "info os".
2089 ** Output logs ("set logging" and related) now include MI output.
2093 ** "set use-deprecated-index-sections on|off"
2094 "show use-deprecated-index-sections on|off"
2095 Controls the use of deprecated .gdb_index sections.
2097 ** "catch load" and "catch unload" can be used to stop when a shared
2098 library is loaded or unloaded, respectively.
2100 ** "enable count" can be used to auto-disable a breakpoint after
2103 ** "info vtbl" can be used to show the virtual method tables for
2104 C++ and Java objects.
2106 ** "explore" and its sub commands "explore value" and "explore type"
2107 can be used to recursively explore values and types of
2108 expressions. These commands are available only if GDB is
2109 configured with '--with-python'.
2111 ** "info auto-load" shows status of all kinds of auto-loaded files,
2112 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2113 sequences of commands files, "info auto-load python-scripts"
2114 shows status of auto-loading Python script files,
2115 "info auto-load local-gdbinit" shows status of loading init file
2116 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2117 status of inferior specific thread debugging shared library loading.
2119 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2120 and "show auto-load-scripts" commands have been deprecated, use their
2121 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2122 and "show auto-load python-scripts" counterparts instead.
2124 ** "dprintf location,format,args..." creates a dynamic printf, which
2125 is basically a breakpoint that does a printf and immediately
2126 resumes your program's execution, so it is like a printf that you
2127 can insert dynamically at runtime instead of at compiletime.
2129 ** "set print symbol"
2131 Controls whether GDB attempts to display the symbol, if any,
2132 corresponding to addresses it prints. This defaults to "on", but
2133 you can set it to "off" to restore GDB's previous behavior.
2135 * Deprecated commands
2137 ** For the Renesas Super-H architecture, the "regs" command has been
2138 deprecated, and "info all-registers" should be used instead.
2142 Renesas RL78 rl78-*-elf
2143 HP OpenVMS ia64 ia64-hp-openvms*
2145 * GDBserver supports evaluation of breakpoint conditions. When
2146 support is advertised by GDBserver, GDB may be told to send the
2147 breakpoint conditions in bytecode form to GDBserver. GDBserver
2148 will only report the breakpoint trigger to GDB when its condition
2153 set mips compression
2154 show mips compression
2155 Select the compressed ISA encoding used in functions that have no symbol
2156 information available. The encoding can be set to either of:
2159 and is updated automatically from ELF file flags if available.
2161 set breakpoint condition-evaluation
2162 show breakpoint condition-evaluation
2163 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2164 GDBserver ("target"). Default option "auto" chooses the most efficient
2166 This option can improve debugger efficiency depending on the speed of the
2170 Disable auto-loading globally.
2173 Show auto-loading setting of all kinds of auto-loaded files.
2175 set auto-load gdb-scripts on|off
2176 show auto-load gdb-scripts
2177 Control auto-loading of GDB canned sequences of commands files.
2179 set auto-load python-scripts on|off
2180 show auto-load python-scripts
2181 Control auto-loading of Python script files.
2183 set auto-load local-gdbinit on|off
2184 show auto-load local-gdbinit
2185 Control loading of init file (.gdbinit) from current directory.
2187 set auto-load libthread-db on|off
2188 show auto-load libthread-db
2189 Control auto-loading of inferior specific thread debugging shared library.
2191 set auto-load scripts-directory <dir1>[:<dir2>...]
2192 show auto-load scripts-directory
2193 Set a list of directories from which to load auto-loaded scripts.
2194 Automatically loaded Python scripts and GDB scripts are located in one
2195 of the directories listed by this option.
2196 The delimiter (':' above) may differ according to the host platform.
2198 set auto-load safe-path <dir1>[:<dir2>...]
2199 show auto-load safe-path
2200 Set a list of directories from which it is safe to auto-load files.
2201 The delimiter (':' above) may differ according to the host platform.
2203 set debug auto-load on|off
2204 show debug auto-load
2205 Control display of debugging info for auto-loading the files above.
2207 set dprintf-style gdb|call|agent
2209 Control the way in which a dynamic printf is performed; "gdb"
2210 requests a GDB printf command, while "call" causes dprintf to call a
2211 function in the inferior. "agent" requests that the target agent
2212 (such as GDBserver) do the printing.
2214 set dprintf-function <expr>
2215 show dprintf-function
2216 set dprintf-channel <expr>
2217 show dprintf-channel
2218 Set the function and optional first argument to the call when using
2219 the "call" style of dynamic printf.
2221 set disconnected-dprintf on|off
2222 show disconnected-dprintf
2223 Control whether agent-style dynamic printfs continue to be in effect
2224 after GDB disconnects.
2226 * New configure options
2228 --with-auto-load-dir
2229 Configure default value for the 'set auto-load scripts-directory'
2230 setting above. It defaults to '$debugdir:$datadir/auto-load',
2231 $debugdir representing global debugging info directories (available
2232 via 'show debug-file-directory') and $datadir representing GDB's data
2233 directory (available via 'show data-directory').
2235 --with-auto-load-safe-path
2236 Configure default value for the 'set auto-load safe-path' setting
2237 above. It defaults to the --with-auto-load-dir setting.
2239 --without-auto-load-safe-path
2240 Set 'set auto-load safe-path' to '/', effectively disabling this
2243 * New remote packets
2245 z0/z1 conditional breakpoints extension
2247 The z0/z1 breakpoint insertion packets have been extended to carry
2248 a list of conditional expressions over to the remote stub depending on the
2249 condition evaluation mode. The use of this extension can be controlled
2250 via the "set remote conditional-breakpoints-packet" command.
2254 Specify the signals which the remote stub may pass to the debugged
2255 program without GDB involvement.
2257 * New command line options
2259 --init-command=FILE, -ix Like --command, -x but execute it
2260 before loading inferior.
2261 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2262 execute it before loading inferior.
2264 *** Changes in GDB 7.4
2266 * GDB now handles ambiguous linespecs more consistently; the existing
2267 FILE:LINE support has been expanded to other types of linespecs. A
2268 breakpoint will now be set on all matching locations in all
2269 inferiors, and locations will be added or removed according to
2272 * GDB now allows you to skip uninteresting functions and files when
2273 stepping with the "skip function" and "skip file" commands.
2275 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2276 and "show remote hardware-watchpoint-length-limit". These allows to
2277 set or show the maximum length limit (in bytes) of a remote
2278 target hardware watchpoint.
2280 This allows e.g. to use "unlimited" hardware watchpoints with the
2281 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2282 watchpoints are slower than real hardware watchpoints but are
2283 significantly faster than gdb software watchpoints.
2287 ** The register_pretty_printer function in module gdb.printing now takes
2288 an optional `replace' argument. If True, the new printer replaces any
2291 ** The "maint set python print-stack on|off" command has been
2292 deprecated and will be deleted in GDB 7.5.
2293 A new command: "set python print-stack none|full|message" has
2294 replaced it. Additionally, the default for "print-stack" is
2295 now "message", which just prints the error message without
2298 ** A prompt substitution hook (prompt_hook) is now available to the
2301 ** A new Python module, gdb.prompt has been added to the GDB Python
2302 modules library. This module provides functionality for
2303 escape sequences in prompts (used by set/show
2304 extended-prompt). These escape sequences are replaced by their
2305 corresponding value.
2307 ** Python commands and convenience-functions located in
2308 'data-directory'/python/gdb/command and
2309 'data-directory'/python/gdb/function are now automatically loaded
2312 ** Blocks now provide four new attributes. global_block and
2313 static_block will return the global and static blocks
2314 respectively. is_static and is_global are boolean attributes
2315 that indicate if the block is one of those two types.
2317 ** Symbols now provide the "type" attribute, the type of the symbol.
2319 ** The "gdb.breakpoint" function has been deprecated in favor of
2322 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2323 of a function. This class is based on the "finish" command
2324 available in the CLI.
2326 ** Type objects for struct and union types now allow access to
2327 the fields using standard Python dictionary (mapping) methods.
2328 For example, "some_type['myfield']" now works, as does
2329 "some_type.items()".
2331 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2334 ** A new function, "deep_items" has been added to the gdb.types
2335 module in the GDB Python modules library. This function returns
2336 an iterator over the fields of a struct or union type. Unlike
2337 the standard Python "iteritems" method, it will recursively traverse
2338 any anonymous fields.
2342 ** "*stopped" events can report several new "reason"s, such as
2345 ** Breakpoint changes are now notified using new async records, like
2346 "=breakpoint-modified".
2348 ** New command -ada-task-info.
2350 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2351 $sdir specifies the default system locations of shared libraries.
2352 $pdir specifies the directory where the libpthread used by the application
2355 GDB no longer looks in $sdir and $pdir after it has searched the directories
2356 mentioned in libthread-db-search-path. If you want to search those
2357 directories, they must be specified in libthread-db-search-path.
2358 The default value of libthread-db-search-path on GNU/Linux and Solaris
2359 systems is now "$sdir:$pdir".
2361 $pdir is not supported by gdbserver, it is currently ignored.
2362 $sdir is supported by gdbserver.
2364 * New configure option --with-iconv-bin.
2365 When using the internationalization support like the one in the GNU C
2366 library, GDB will invoke the "iconv" program to get a list of supported
2367 character sets. If this program lives in a non-standard location, one can
2368 use this option to specify where to find it.
2370 * When natively debugging programs on PowerPC BookE processors running
2371 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2372 watchpoints, which specify a mask in addition to an address to watch.
2373 The mask specifies that some bits of an address (the bits which are
2374 reset in the mask) should be ignored when matching the address accessed
2375 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2376 section in the user manual for more details.
2378 * The new option --once causes GDBserver to stop listening for connections once
2379 the first connection is made. The listening port used by GDBserver will
2380 become available after that.
2382 * New commands "info macros" and "alias" have been added.
2384 * New function parameters suffix @entry specifies value of function parameter
2385 at the time the function got called. Entry values are available only since
2391 "!" is now an alias of the "shell" command.
2392 Note that no space is needed between "!" and SHELL COMMAND.
2396 watch EXPRESSION mask MASK_VALUE
2397 The watch command now supports the mask argument which allows creation
2398 of masked watchpoints, if the current architecture supports this feature.
2400 info auto-load-scripts [REGEXP]
2401 This command was formerly named "maintenance print section-scripts".
2402 It is now generally useful and is no longer a maintenance-only command.
2404 info macro [-all] [--] MACRO
2405 The info macro command has new options `-all' and `--'. The first for
2406 printing all definitions of a macro. The second for explicitly specifying
2407 the end of arguments and the beginning of the macro name in case the macro
2408 name starts with a hyphen.
2410 collect[/s] EXPRESSIONS
2411 The tracepoint collect command now takes an optional modifier "/s"
2412 that directs it to dereference pointer-to-character types and
2413 collect the bytes of memory up to a zero byte. The behavior is
2414 similar to what you see when you use the regular print command on a
2415 string. An optional integer following the "/s" sets a bound on the
2416 number of bytes that will be collected.
2419 The trace start command now interprets any supplied arguments as a
2420 note to be recorded with the trace run, with an effect similar to
2421 setting the variable trace-notes.
2424 The trace stop command now interprets any arguments as a note to be
2425 mentioned along with the tstatus report that the trace was stopped
2426 with a command. The effect is similar to setting the variable
2429 * Tracepoints can now be enabled and disabled at any time after a trace
2430 experiment has been started using the standard "enable" and "disable"
2431 commands. It is now possible to start a trace experiment with no enabled
2432 tracepoints; GDB will display a warning, but will allow the experiment to
2433 begin, assuming that tracepoints will be enabled as needed while the trace
2436 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2437 locations with 4-byte instructions, when they were previously
2438 limited to locations with instructions of 5 bytes or longer.
2442 set debug dwarf2-read
2443 show debug dwarf2-read
2444 Turns on or off display of debugging messages related to reading
2445 DWARF debug info. The default is off.
2447 set debug symtab-create
2448 show debug symtab-create
2449 Turns on or off display of debugging messages related to symbol table
2450 creation. The default is off.
2453 show extended-prompt
2454 Set the GDB prompt, and allow escape sequences to be inserted to
2455 display miscellaneous information (see 'help set extended-prompt'
2456 for the list of sequences). This prompt (and any information
2457 accessed through the escape sequences) is updated every time the
2458 prompt is displayed.
2460 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2461 show print entry-values
2462 Set printing of frame argument values at function entry. In some cases
2463 GDB can determine the value of function argument which was passed by the
2464 function caller, even if the value was modified inside the called function.
2466 set debug entry-values
2467 show debug entry-values
2468 Control display of debugging info for determining frame argument values at
2469 function entry and virtual tail call frames.
2471 set basenames-may-differ
2472 show basenames-may-differ
2473 Set whether a source file may have multiple base names.
2474 (A "base name" is the name of a file with the directory part removed.
2475 Example: The base name of "/home/user/hello.c" is "hello.c".)
2476 If set, GDB will canonicalize file names (e.g., expand symlinks)
2477 before comparing them. Canonicalization is an expensive operation,
2478 but it allows the same file be known by more than one base name.
2479 If not set (the default), all source files are assumed to have just
2480 one base name, and gdb will do file name comparisons more efficiently.
2486 Set a user name and notes for the current and any future trace runs.
2487 This is useful for long-running and/or disconnected traces, to
2488 inform others (or yourself) as to who is running the trace, supply
2489 contact information, or otherwise explain what is going on.
2491 set trace-stop-notes
2492 show trace-stop-notes
2493 Set a note attached to the trace run, that is displayed when the
2494 trace has been stopped by a tstop command. This is useful for
2495 instance as an explanation, if you are stopping a trace run that was
2496 started by someone else.
2498 * New remote packets
2502 Dynamically enable a tracepoint in a started trace experiment.
2506 Dynamically disable a tracepoint in a started trace experiment.
2510 Set the user and notes of the trace run.
2514 Query the current status of a tracepoint.
2518 Query the minimum length of instruction at which a fast tracepoint may
2521 * Dcache size (number of lines) and line-size are now runtime-configurable
2522 via "set dcache line" and "set dcache line-size" commands.
2526 Texas Instruments TMS320C6x tic6x-*-*
2530 Renesas RL78 rl78-*-elf
2532 *** Changes in GDB 7.3.1
2534 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2536 *** Changes in GDB 7.3
2538 * GDB has a new command: "thread find [REGEXP]".
2539 It finds the thread id whose name, target id, or thread extra info
2540 matches the given regular expression.
2542 * The "catch syscall" command now works on mips*-linux* targets.
2544 * The -data-disassemble MI command now supports modes 2 and 3 for
2545 dumping the instruction opcodes.
2547 * New command line options
2549 -data-directory DIR Specify DIR as the "data-directory".
2550 This is mostly for testing purposes.
2552 * The "maint set python auto-load on|off" command has been renamed to
2553 "set auto-load-scripts on|off".
2555 * GDB has a new command: "set directories".
2556 It is like the "dir" command except that it replaces the
2557 source path list instead of augmenting it.
2559 * GDB now understands thread names.
2561 On GNU/Linux, "info threads" will display the thread name as set by
2562 prctl or pthread_setname_np.
2564 There is also a new command, "thread name", which can be used to
2565 assign a name internally for GDB to display.
2568 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2569 has been integrated into GDB.
2573 ** The function gdb.Write now accepts an optional keyword 'stream'.
2574 This keyword, when provided, will direct the output to either
2575 stdout, stderr, or GDB's logging output.
2577 ** Parameters can now be be sub-classed in Python, and in particular
2578 you may implement the get_set_doc and get_show_doc functions.
2579 This improves how Parameter set/show documentation is processed
2580 and allows for more dynamic content.
2582 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2583 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2584 have an is_valid method.
2586 ** Breakpoints can now be sub-classed in Python, and in particular
2587 you may implement a 'stop' function that is executed each time
2588 the inferior reaches that breakpoint.
2590 ** New function gdb.lookup_global_symbol looks up a global symbol.
2592 ** GDB values in Python are now callable if the value represents a
2593 function. For example, if 'some_value' represents a function that
2594 takes two integer parameters and returns a value, you can call
2595 that function like so:
2597 result = some_value (10,20)
2599 ** Module gdb.types has been added.
2600 It contains a collection of utilities for working with gdb.Types objects:
2601 get_basic_type, has_field, make_enum_dict.
2603 ** Module gdb.printing has been added.
2604 It contains utilities for writing and registering pretty-printers.
2605 New classes: PrettyPrinter, SubPrettyPrinter,
2606 RegexpCollectionPrettyPrinter.
2607 New function: register_pretty_printer.
2609 ** New commands "info pretty-printers", "enable pretty-printer" and
2610 "disable pretty-printer" have been added.
2612 ** gdb.parameter("directories") is now available.
2614 ** New function gdb.newest_frame returns the newest frame in the
2617 ** The gdb.InferiorThread class has a new "name" attribute. This
2618 holds the thread's name.
2620 ** Python Support for Inferior events.
2621 Python scripts can add observers to be notified of events
2622 occurring in the process being debugged.
2623 The following events are currently supported:
2624 - gdb.events.cont Continue event.
2625 - gdb.events.exited Inferior exited event.
2626 - gdb.events.stop Signal received, and Breakpoint hit events.
2630 ** GDB now puts template parameters in scope when debugging in an
2631 instantiation. For example, if you have:
2633 template<int X> int func (void) { return X; }
2635 then if you step into func<5>, "print X" will show "5". This
2636 feature requires proper debuginfo support from the compiler; it
2637 was added to GCC 4.5.
2639 ** The motion commands "next", "finish", "until", and "advance" now
2640 work better when exceptions are thrown. In particular, GDB will
2641 no longer lose control of the inferior; instead, the GDB will
2642 stop the inferior at the point at which the exception is caught.
2643 This functionality requires a change in the exception handling
2644 code that was introduced in GCC 4.5.
2646 * GDB now follows GCC's rules on accessing volatile objects when
2647 reading or writing target state during expression evaluation.
2648 One notable difference to prior behavior is that "print x = 0"
2649 no longer generates a read of x; the value of the assignment is
2650 now always taken directly from the value being assigned.
2652 * GDB now has some support for using labels in the program's source in
2653 linespecs. For instance, you can use "advance label" to continue
2654 execution to a label.
2656 * GDB now has support for reading and writing a new .gdb_index
2657 section. This section holds a fast index of DWARF debugging
2658 information and can be used to greatly speed up GDB startup and
2659 operation. See the documentation for `save gdb-index' for details.
2661 * The "watch" command now accepts an optional "-location" argument.
2662 When used, this causes GDB to watch the memory referred to by the
2663 expression. Such a watchpoint is never deleted due to it going out
2666 * GDB now supports thread debugging of core dumps on GNU/Linux.
2668 GDB now activates thread debugging using the libthread_db library
2669 when debugging GNU/Linux core dumps, similarly to when debugging
2670 live processes. As a result, when debugging a core dump file, GDB
2671 is now able to display pthread_t ids of threads. For example, "info
2672 threads" shows the same output as when debugging the process when it
2673 was live. In earlier releases, you'd see something like this:
2676 * 1 LWP 6780 main () at main.c:10
2678 While now you see this:
2681 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2683 It is also now possible to inspect TLS variables when debugging core
2686 When debugging a core dump generated on a machine other than the one
2687 used to run GDB, you may need to point GDB at the correct
2688 libthread_db library with the "set libthread-db-search-path"
2689 command. See the user manual for more details on this command.
2691 * When natively debugging programs on PowerPC BookE processors running
2692 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2693 which stop execution of the inferior whenever it executes an instruction
2694 at any address within the specified range. See the "PowerPC Embedded"
2695 section in the user manual for more details.
2697 * New features in the GDB remote stub, GDBserver
2699 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2700 and i686 LynxOS (version 5.x).
2702 ** GDBserver is now supported on Blackfin Linux.
2704 * New native configurations
2706 ia64 HP-UX ia64-*-hpux*
2710 Analog Devices, Inc. Blackfin Processor bfin-*
2712 * Ada task switching is now supported on sparc-elf targets when
2713 debugging a program using the Ravenscar Profile. For more information,
2714 see the "Tasking Support when using the Ravenscar Profile" section
2715 in the GDB user manual.
2717 * Guile support was removed.
2719 * New features in the GNU simulator
2721 ** The --map-info flag lists all known core mappings.
2723 ** CFI flashes may be simulated via the "cfi" device.
2725 *** Changes in GDB 7.2
2727 * Shared library support for remote targets by default
2729 When GDB is configured for a generic, non-OS specific target, like
2730 for example, --target=arm-eabi or one of the many *-*-elf targets,
2731 GDB now queries remote stubs for loaded shared libraries using the
2732 `qXfer:libraries:read' packet. Previously, shared library support
2733 was always disabled for such configurations.
2737 ** Argument Dependent Lookup (ADL)
2739 In C++ ADL lookup directs function search to the namespaces of its
2740 arguments even if the namespace has not been imported.
2750 Here the compiler will search for `foo' in the namespace of 'b'
2751 and find A::foo. GDB now supports this. This construct is commonly
2752 used in the Standard Template Library for operators.
2754 ** Improved User Defined Operator Support
2756 In addition to member operators, GDB now supports lookup of operators
2757 defined in a namespace and imported with a `using' directive, operators
2758 defined in the global scope, operators imported implicitly from an
2759 anonymous namespace, and the ADL operators mentioned in the previous
2761 GDB now also supports proper overload resolution for all the previously
2762 mentioned flavors of operators.
2764 ** static const class members
2766 Printing of static const class members that are initialized in the
2767 class definition has been fixed.
2769 * Windows Thread Information Block access.
2771 On Windows targets, GDB now supports displaying the Windows Thread
2772 Information Block (TIB) structure. This structure is visible either
2773 by using the new command `info w32 thread-information-block' or, by
2774 dereferencing the new convenience variable named `$_tlb', a
2775 thread-specific pointer to the TIB. This feature is also supported
2776 when remote debugging using GDBserver.
2778 * Static tracepoints
2780 Static tracepoints are calls in the user program into a tracing
2781 library. One such library is a port of the LTTng kernel tracer to
2782 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2783 When debugging with GDBserver, GDB now supports combining the GDB
2784 tracepoint machinery with such libraries. For example: the user can
2785 use GDB to probe a static tracepoint marker (a call from the user
2786 program into the tracing library) with the new "strace" command (see
2787 "New commands" below). This creates a "static tracepoint" in the
2788 breakpoint list, that can be manipulated with the same feature set
2789 as fast and regular tracepoints. E.g., collect registers, local and
2790 global variables, collect trace state variables, and define
2791 tracepoint conditions. In addition, the user can collect extra
2792 static tracepoint marker specific data, by collecting the new
2793 $_sdata internal variable. When analyzing the trace buffer, you can
2794 inspect $_sdata like any other variable available to GDB. For more
2795 information, see the "Tracepoints" chapter in GDB user manual. New
2796 remote packets have been defined to support static tracepoints, see
2797 the "New remote packets" section below.
2799 * Better reconstruction of tracepoints after disconnected tracing
2801 GDB will attempt to download the original source form of tracepoint
2802 definitions when starting a trace run, and then will upload these
2803 upon reconnection to the target, resulting in a more accurate
2804 reconstruction of the tracepoints that are in use on the target.
2808 You can now exercise direct control over the ways that GDB can
2809 affect your program. For instance, you can disallow the setting of
2810 breakpoints, so that the program can run continuously (assuming
2811 non-stop mode). In addition, the "observer" variable is available
2812 to switch all of the different controls; in observer mode, GDB
2813 cannot affect the target's behavior at all, which is useful for
2814 tasks like diagnosing live systems in the field.
2816 * The new convenience variable $_thread holds the number of the
2819 * New remote packets
2823 Return the address of the Windows Thread Information Block of a given thread.
2827 In response to several of the tracepoint packets, the target may now
2828 also respond with a number of intermediate `qRelocInsn' request
2829 packets before the final result packet, to have GDB handle
2830 relocating an instruction to execute at a different address. This
2831 is particularly useful for stubs that support fast tracepoints. GDB
2832 reports support for this feature in the qSupported packet.
2836 List static tracepoint markers in the target program.
2840 List static tracepoint markers at a given address in the target
2843 qXfer:statictrace:read
2845 Read the static trace data collected (by a `collect $_sdata'
2846 tracepoint action). The remote stub reports support for this packet
2847 to gdb's qSupported query.
2851 Send the current settings of GDB's permission flags.
2855 Send part of the source (textual) form of a tracepoint definition,
2856 which includes location, conditional, and action list.
2858 * The source command now accepts a -s option to force searching for the
2859 script in the source search path even if the script name specifies
2862 * New features in the GDB remote stub, GDBserver
2864 - GDBserver now support tracepoints (including fast tracepoints, and
2865 static tracepoints). The feature is currently supported by the
2866 i386-linux and amd64-linux builds. See the "Tracepoints support
2867 in gdbserver" section in the manual for more information.
2869 GDBserver JIT compiles the tracepoint's conditional agent
2870 expression bytecode into native code whenever possible for low
2871 overhead dynamic tracepoints conditionals. For such tracepoints,
2872 an expression that examines program state is evaluated when the
2873 tracepoint is reached, in order to determine whether to capture
2874 trace data. If the condition is simple and false, processing the
2875 tracepoint finishes very quickly and no data is gathered.
2877 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2878 for static tracepoints support.
2880 - GDBserver now supports x86_64 Windows 64-bit debugging.
2882 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2883 it understands register description.
2885 * The --batch flag now disables pagination and queries.
2887 * X86 general purpose registers
2889 GDB now supports reading/writing byte, word and double-word x86
2890 general purpose registers directly. This means you can use, say,
2891 $ah or $ax to refer, respectively, to the byte register AH and
2892 16-bit word register AX that are actually portions of the 32-bit
2893 register EAX or 64-bit register RAX.
2895 * The `commands' command now accepts a range of breakpoints to modify.
2896 A plain `commands' following a command that creates multiple
2897 breakpoints affects all the breakpoints set by that command. This
2898 applies to breakpoints set by `rbreak', and also applies when a
2899 single `break' command creates multiple breakpoints (e.g.,
2900 breakpoints on overloaded c++ functions).
2902 * The `rbreak' command now accepts a filename specification as part of
2903 its argument, limiting the functions selected by the regex to those
2904 in the specified file.
2906 * Support for remote debugging Windows and SymbianOS shared libraries
2907 from Unix hosts has been improved. Non Windows GDB builds now can
2908 understand target reported file names that follow MS-DOS based file
2909 system semantics, such as file names that include drive letters and
2910 use the backslash character as directory separator. This makes it
2911 possible to transparently use the "set sysroot" and "set
2912 solib-search-path" on Unix hosts to point as host copies of the
2913 target's shared libraries. See the new command "set
2914 target-file-system-kind" described below, and the "Commands to
2915 specify files" section in the user manual for more information.
2919 eval template, expressions...
2920 Convert the values of one or more expressions under the control
2921 of the string template to a command line, and call it.
2923 set target-file-system-kind unix|dos-based|auto
2924 show target-file-system-kind
2925 Set or show the assumed file system kind for target reported file
2928 save breakpoints <filename>
2929 Save all current breakpoint definitions to a file suitable for use
2930 in a later debugging session. To read the saved breakpoint
2931 definitions, use the `source' command.
2933 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2936 info static-tracepoint-markers
2937 Display information about static tracepoint markers in the target.
2939 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2940 Define a static tracepoint by probing a marker at the given
2941 function, line, address, or marker ID.
2945 Enable and disable observer mode.
2947 set may-write-registers on|off
2948 set may-write-memory on|off
2949 set may-insert-breakpoints on|off
2950 set may-insert-tracepoints on|off
2951 set may-insert-fast-tracepoints on|off
2952 set may-interrupt on|off
2953 Set individual permissions for GDB effects on the target. Note that
2954 some of these settings can have undesirable or surprising
2955 consequences, particularly when changed in the middle of a session.
2956 For instance, disabling the writing of memory can prevent
2957 breakpoints from being inserted, cause single-stepping to fail, or
2958 even crash your program, if you disable after breakpoints have been
2959 inserted. However, GDB should not crash.
2961 set record memory-query on|off
2962 show record memory-query
2963 Control whether to stop the inferior if memory changes caused
2964 by an instruction cannot be recorded.
2969 The disassemble command now supports "start,+length" form of two arguments.
2973 ** GDB now provides a new directory location, called the python directory,
2974 where Python scripts written for GDB can be installed. The location
2975 of that directory is <data-directory>/python, where <data-directory>
2976 is the GDB data directory. For more details, see section `Scripting
2977 GDB using Python' in the manual.
2979 ** The GDB Python API now has access to breakpoints, symbols, symbol
2980 tables, program spaces, inferiors, threads and frame's code blocks.
2981 Additionally, GDB Parameters can now be created from the API, and
2982 manipulated via set/show in the CLI.
2984 ** New functions gdb.target_charset, gdb.target_wide_charset,
2985 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2987 ** New exception gdb.GdbError.
2989 ** Pretty-printers are now also looked up in the current program space.
2991 ** Pretty-printers can now be individually enabled and disabled.
2993 ** GDB now looks for names of Python scripts to auto-load in a
2994 special section named `.debug_gdb_scripts', in addition to looking
2995 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2997 * Tracepoint actions were unified with breakpoint commands. In particular,
2998 there are no longer differences in "info break" output for breakpoints and
2999 tracepoints and the "commands" command can be used for both tracepoints and
3000 regular breakpoints.
3004 ARM Symbian arm*-*-symbianelf*
3006 * D language support.
3007 GDB now supports debugging programs written in the D programming
3010 * GDB now supports the extended ptrace interface for PowerPC which is
3011 available since Linux kernel version 2.6.34. This automatically enables
3012 any hardware breakpoints and additional hardware watchpoints available in
3013 the processor. The old ptrace interface exposes just one hardware
3014 watchpoint and no hardware breakpoints.
3016 * GDB is now able to use the Data Value Compare (DVC) register available on
3017 embedded PowerPC processors to implement in hardware simple watchpoint
3018 conditions of the form:
3020 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3022 This works in native GDB running on Linux kernels with the extended ptrace
3023 interface mentioned above.
3025 *** Changes in GDB 7.1
3029 ** Namespace Support
3031 GDB now supports importing of namespaces in C++. This enables the
3032 user to inspect variables from imported namespaces. Support for
3033 namepace aliasing has also been added. So, if a namespace is
3034 aliased in the current scope (e.g. namepace C=A; ) the user can
3035 print variables using the alias (e.g. (gdb) print C::x).
3039 All known bugs relating to the printing of virtual base class were
3040 fixed. It is now possible to call overloaded static methods using a
3045 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3046 and reinterpret_cast<> are now handled by the C++ expression parser.
3050 Xilinx MicroBlaze microblaze-*-*
3055 Xilinx MicroBlaze microblaze
3058 * Multi-program debugging.
3060 GDB now has support for multi-program (a.k.a. multi-executable or
3061 multi-exec) debugging. This allows for debugging multiple inferiors
3062 simultaneously each running a different program under the same GDB
3063 session. See "Debugging Multiple Inferiors and Programs" in the
3064 manual for more information. This implied some user visible changes
3065 in the multi-inferior support. For example, "info inferiors" now
3066 lists inferiors that are not running yet or that have exited
3067 already. See also "New commands" and "New options" below.
3069 * New tracing features
3071 GDB's tracepoint facility now includes several new features:
3073 ** Trace state variables
3075 GDB tracepoints now include support for trace state variables, which
3076 are variables managed by the target agent during a tracing
3077 experiment. They are useful for tracepoints that trigger each
3078 other, so for instance one tracepoint can count hits in a variable,
3079 and then a second tracepoint has a condition that is true when the
3080 count reaches a particular value. Trace state variables share the
3081 $-syntax of GDB convenience variables, and can appear in both
3082 tracepoint actions and condition expressions. Use the "tvariable"
3083 command to create, and "info tvariables" to view; see "Trace State
3084 Variables" in the manual for more detail.
3088 GDB now includes an option for defining fast tracepoints, which
3089 targets may implement more efficiently, such as by installing a jump
3090 into the target agent rather than a trap instruction. The resulting
3091 speedup can be by two orders of magnitude or more, although the
3092 tradeoff is that some program locations on some target architectures
3093 might not allow fast tracepoint installation, for instance if the
3094 instruction to be replaced is shorter than the jump. To request a
3095 fast tracepoint, use the "ftrace" command, with syntax identical to
3096 the regular trace command.
3098 ** Disconnected tracing
3100 It is now possible to detach GDB from the target while it is running
3101 a trace experiment, then reconnect later to see how the experiment
3102 is going. In addition, a new variable disconnected-tracing lets you
3103 tell the target agent whether to continue running a trace if the
3104 connection is lost unexpectedly.
3108 GDB now has the ability to save the trace buffer into a file, and
3109 then use that file as a target, similarly to you can do with
3110 corefiles. You can select trace frames, print data that was
3111 collected in them, and use tstatus to display the state of the
3112 tracing run at the moment that it was saved. To create a trace
3113 file, use "tsave <filename>", and to use it, do "target tfile
3116 ** Circular trace buffer
3118 You can ask the target agent to handle the trace buffer as a
3119 circular buffer, discarding the oldest trace frames to make room for
3120 newer ones, by setting circular-trace-buffer to on. This feature may
3121 not be available for all target agents.
3126 The disassemble command, when invoked with two arguments, now requires
3127 the arguments to be comma-separated.
3130 The info variables command now displays variable definitions. Files
3131 which only declare a variable are not shown.
3134 The source command is now capable of sourcing Python scripts.
3135 This feature is dependent on the debugger being build with Python
3138 Related to this enhancement is also the introduction of a new command
3139 "set script-extension" (see below).
3141 * New commands (for set/show, see "New options" below)
3143 record save [<FILENAME>]
3144 Save a file (in core file format) containing the process record
3145 execution log for replay debugging at a later time.
3147 record restore <FILENAME>
3148 Restore the process record execution log that was saved at an
3149 earlier time, for replay debugging.
3151 add-inferior [-copies <N>] [-exec <FILENAME>]
3154 clone-inferior [-copies <N>] [ID]
3155 Make a new inferior ready to execute the same program another
3156 inferior has loaded.
3161 maint info program-spaces
3162 List the program spaces loaded into GDB.
3164 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3165 show remote interrupt-sequence
3166 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3167 as the sequence to the remote target in order to interrupt the execution.
3168 Ctrl-C is a default. Some system prefers BREAK which is high level of
3169 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3170 Magic SysRq g. It is BREAK signal and character 'g'.
3172 set remote interrupt-on-connect [on | off]
3173 show remote interrupt-on-connect
3174 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3175 remote target when gdb connects to it. This is needed when you debug
3178 set remotebreak [on | off]
3180 Deprecated. Use "set/show remote interrupt-sequence" instead.
3182 tvariable $NAME [ = EXP ]
3183 Create or modify a trace state variable.
3186 List trace state variables and their values.
3188 delete tvariable $NAME ...
3189 Delete one or more trace state variables.
3192 Evaluate the given expressions without collecting anything into the
3193 trace buffer. (Valid in tracepoint actions only.)
3195 ftrace FN / FILE:LINE / *ADDR
3196 Define a fast tracepoint at the given function, line, or address.
3198 * New expression syntax
3200 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3201 GDB now parses 0b101010 identically with 42.
3205 set follow-exec-mode new|same
3206 show follow-exec-mode
3207 Control whether GDB reuses the same inferior across an exec call or
3208 creates a new one. This is useful to be able to restart the old
3209 executable after the inferior having done an exec call.
3211 set default-collect EXPR, ...
3212 show default-collect
3213 Define a list of expressions to be collected at each tracepoint.
3214 This is a useful way to ensure essential items are not overlooked,
3215 such as registers or a critical global variable.
3217 set disconnected-tracing
3218 show disconnected-tracing
3219 If set to 1, the target is instructed to continue tracing if it
3220 loses its connection to GDB. If 0, the target is to stop tracing
3223 set circular-trace-buffer
3224 show circular-trace-buffer
3225 If set to on, the target is instructed to use a circular trace buffer
3226 and discard the oldest trace frames instead of stopping the trace due
3227 to a full trace buffer. If set to off, the trace stops when the buffer
3228 fills up. Some targets may not support this.
3230 set script-extension off|soft|strict
3231 show script-extension
3232 If set to "off", the debugger does not perform any script language
3233 recognition, and all sourced files are assumed to be GDB scripts.
3234 If set to "soft" (the default), files are sourced according to
3235 filename extension, falling back to GDB scripts if the first
3237 If set to "strict", files are sourced according to filename extension.
3239 set ada trust-PAD-over-XVS on|off
3240 show ada trust-PAD-over-XVS
3241 If off, activate a workaround against a bug in the debugging information
3242 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3243 the GCC sources for more information about the GNAT encoding and
3244 PAD types in particular). It is always safe to set this option to
3245 off, but this introduces a slight performance penalty. The default
3248 * Python API Improvements
3250 ** GDB provides the new class gdb.LazyString. This is useful in
3251 some pretty-printing cases. The new method gdb.Value.lazy_string
3252 provides a simple way to create objects of this type.
3254 ** The fields returned by gdb.Type.fields now have an
3255 `is_base_class' attribute.
3257 ** The new method gdb.Type.range returns the range of an array type.
3259 ** The new method gdb.parse_and_eval can be used to parse and
3260 evaluate an expression.
3262 * New remote packets
3265 Define a trace state variable.
3268 Get the current value of a trace state variable.
3271 Set desired tracing behavior upon disconnection.
3274 Set the trace buffer to be linear or circular.
3277 Get data about the tracepoints currently in use.
3281 Process record now works correctly with hardware watchpoints.
3283 Multiple bug fixes have been made to the mips-irix port, making it
3284 much more reliable. In particular:
3285 - Debugging threaded applications is now possible again. Previously,
3286 GDB would hang while starting the program, or while waiting for
3287 the program to stop at a breakpoint.
3288 - Attaching to a running process no longer hangs.
3289 - An error occurring while loading a core file has been fixed.
3290 - Changing the value of the PC register now works again. This fixes
3291 problems observed when using the "jump" command, or when calling
3292 a function from GDB, or even when assigning a new value to $pc.
3293 - With the "finish" and "return" commands, the return value for functions
3294 returning a small array is now correctly printed.
3295 - It is now possible to break on shared library code which gets executed
3296 during a shared library init phase (code executed while executing
3297 their .init section). Previously, the breakpoint would have no effect.
3298 - GDB is now able to backtrace through the signal handler for
3299 non-threaded programs.
3301 PIE (Position Independent Executable) programs debugging is now supported.
3302 This includes debugging execution of PIC (Position Independent Code) shared
3303 libraries although for that, it should be possible to run such libraries as an
3306 *** Changes in GDB 7.0
3308 * GDB now has an interface for JIT compilation. Applications that
3309 dynamically generate code can create symbol files in memory and register
3310 them with GDB. For users, the feature should work transparently, and
3311 for JIT developers, the interface is documented in the GDB manual in the
3312 "JIT Compilation Interface" chapter.
3314 * Tracepoints may now be conditional. The syntax is as for
3315 breakpoints; either an "if" clause appended to the "trace" command,
3316 or the "condition" command is available. GDB sends the condition to
3317 the target for evaluation using the same bytecode format as is used
3318 for tracepoint actions.
3320 * The disassemble command now supports: an optional /r modifier, print the
3321 raw instructions in hex as well as in symbolic form, and an optional /m
3322 modifier to print mixed source+assembly.
3324 * Process record and replay
3326 In a architecture environment that supports ``process record and
3327 replay'', ``process record and replay'' target can record a log of
3328 the process execution, and replay it with both forward and reverse
3331 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3332 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3333 set execution-direction {forward|reverse}, for targets that support
3336 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3337 feature is available with a native GDB running on kernel version
3340 * GDB now has support for multi-byte and wide character sets on the
3341 target. Strings whose character type is wchar_t, char16_t, or
3342 char32_t are now correctly printed. GDB supports wide- and unicode-
3343 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3344 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3345 `printf'. This feature requires iconv to work properly; if your
3346 system does not have a working iconv, GDB can use GNU libiconv. See
3347 the installation instructions for more information.
3349 * GDB now supports automatic retrieval of shared library files from
3350 remote targets. To use this feature, specify a system root that begins
3351 with the `remote:' prefix, either via the `set sysroot' command or via
3352 the `--with-sysroot' configure-time option.
3354 * "info sharedlibrary" now takes an optional regex of libraries to show,
3355 and it now reports if a shared library has no debugging information.
3357 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3358 now complete on file names.
3360 * When completing in expressions, gdb will attempt to limit
3361 completions to allowable structure or union fields, where appropriate.
3362 For instance, consider:
3364 # struct example { int f1; double f2; };
3365 # struct example variable;
3368 If the user types TAB at the end of this command line, the available
3369 completions will be "f1" and "f2".
3371 * Inlined functions are now supported. They show up in backtraces, and
3372 the "step", "next", and "finish" commands handle them automatically.
3374 * GDB now supports the token-splicing (##) and stringification (#)
3375 operators when expanding macros. It also supports variable-arity
3378 * GDB now supports inspecting extra signal information, exported by
3379 the new $_siginfo convenience variable. The feature is currently
3380 implemented on linux ARM, i386 and amd64.
3382 * GDB can now display the VFP floating point registers and NEON vector
3383 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3384 can provide these registers (requires Linux 2.6.30 or later). Remote
3385 and simulator targets may also provide them.
3387 * New remote packets
3390 Search memory for a sequence of bytes.
3393 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3394 operation over reliable transport links. Use of this packet is
3395 controlled by the `set remote noack-packet' command.
3398 Kill the process with the specified process ID. Use this in preference
3399 to `k' when multiprocess protocol extensions are supported.
3402 Obtains additional operating system information
3406 Read or write additional signal information.
3408 * Removed remote protocol undocumented extension
3410 An undocumented extension to the remote protocol's `S' stop reply
3411 packet that permited the stub to pass a process id was removed.
3412 Remote servers should use the `T' stop reply packet instead.
3414 * GDB now supports multiple function calling conventions according to the
3415 DWARF-2 DW_AT_calling_convention function attribute.
3417 * The SH target utilizes the aforementioned change to distinguish between gcc
3418 and Renesas calling convention. It also adds the new CLI commands
3419 `set/show sh calling-convention'.
3421 * GDB can now read compressed debug sections, as produced by GNU gold
3422 with the --compress-debug-sections=zlib flag.
3424 * 64-bit core files are now supported on AIX.
3426 * Thread switching is now supported on Tru64.
3428 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3429 which will be allocated using malloc later in program execution.
3431 * The qXfer:libraries:read remote procotol packet now allows passing a
3432 list of section offsets.
3434 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3435 conditions handling signals delivered during attach or thread creation
3436 have also been fixed.
3438 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3439 From the user's standpoint, all unqualified instances of True and False
3440 are treated as the standard definitions, regardless of context.
3442 * GDB now parses C++ symbol and type names more flexibly. For
3445 template<typename T> class C { };
3448 GDB will now correctly handle all of:
3450 ptype C<char const *>
3451 ptype C<char const*>
3452 ptype C<const char *>
3453 ptype C<const char*>
3455 * New features in the GDB remote stub, gdbserver
3457 - The "--wrapper" command-line argument tells gdbserver to use a
3458 wrapper program to launch programs for debugging.
3460 - On PowerPC and S/390 targets, it is now possible to use a single
3461 gdbserver executable to debug both 32-bit and 64-bit programs.
3462 (This requires gdbserver itself to be built as a 64-bit executable.)
3464 - gdbserver uses the new noack protocol mode for TCP connections to
3465 reduce communications latency, if also supported and enabled in GDB.
3467 - Support for the sparc64-linux-gnu target is now included in
3470 - The amd64-linux build of gdbserver now supports debugging both
3471 32-bit and 64-bit programs.
3473 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3474 now support hardware watchpoints, and will use them automatically
3479 GDB now has support for scripting using Python. Whether this is
3480 available is determined at configure time.
3482 New GDB commands can now be written in Python.
3484 * Ada tasking support
3486 Ada tasks can now be inspected in GDB. The following commands have
3490 Print the list of Ada tasks.
3492 Print detailed information about task number N.
3494 Print the task number of the current task.
3496 Switch the context of debugging to task number N.
3498 * Support for user-defined prefixed commands. The "define" command can
3499 add new commands to existing prefixes, e.g. "target".
3501 * Multi-inferior, multi-process debugging.
3503 GDB now has generalized support for multi-inferior debugging. See
3504 "Debugging Multiple Inferiors" in the manual for more information.
3505 Although availability still depends on target support, the command
3506 set is more uniform now. The GNU/Linux specific multi-forks support
3507 has been migrated to this new framework. This implied some user
3508 visible changes; see "New commands" and also "Removed commands"
3511 * Target descriptions can now describe the target OS ABI. See the
3512 "Target Description Format" section in the user manual for more
3515 * Target descriptions can now describe "compatible" architectures
3516 to indicate that the target can execute applications for a different
3517 architecture in addition to those for the main target architecture.
3518 See the "Target Description Format" section in the user manual for
3521 * Multi-architecture debugging.
3523 GDB now includes general supports for debugging applications on
3524 hybrid systems that use more than one single processor architecture
3525 at the same time. Each such hybrid architecture still requires
3526 specific support to be added. The only hybrid architecture supported
3527 in this version of GDB is the Cell Broadband Engine.
3529 * GDB now supports integrated debugging of Cell/B.E. applications that
3530 use both the PPU and SPU architectures. To enable support for hybrid
3531 Cell/B.E. debugging, you need to configure GDB to support both the
3532 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3533 --enable-targets configure option.
3535 * Non-stop mode debugging.
3537 For some targets, GDB now supports an optional mode of operation in
3538 which you can examine stopped threads while other threads continue
3539 to execute freely. This is referred to as non-stop mode, with the
3540 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3541 section in the user manual for more information.
3543 To be able to support remote non-stop debugging, a remote stub needs
3544 to implement the non-stop mode remote protocol extensions, as
3545 described in the "Remote Non-Stop" section of the user manual. The
3546 GDB remote stub, gdbserver, has been adjusted to support these
3547 extensions on linux targets.
3549 * New commands (for set/show, see "New options" below)
3551 catch syscall [NAME(S) | NUMBER(S)]
3552 Catch system calls. Arguments, which should be names of system
3553 calls or their numbers, mean catch only those syscalls. Without
3554 arguments, every syscall will be caught. When the inferior issues
3555 any of the specified syscalls, GDB will stop and announce the system
3556 call, both when it is called and when its call returns. This
3557 feature is currently available with a native GDB running on the
3558 Linux Kernel, under the following architectures: x86, x86_64,
3559 PowerPC and PowerPC64.
3561 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3563 Search memory for a sequence of bytes.
3565 maint set python print-stack
3566 maint show python print-stack
3567 Show a stack trace when an error is encountered in a Python script.
3570 Invoke CODE by passing it to the Python interpreter.
3575 These allow macros to be defined, undefined, and listed
3579 Show operating system information about processes.
3582 List the inferiors currently under GDB's control.
3585 Switch focus to inferior number NUM.
3588 Detach from inferior number NUM.
3591 Kill inferior number NUM.
3595 set spu stop-on-load
3596 show spu stop-on-load
3597 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3599 set spu auto-flush-cache
3600 show spu auto-flush-cache
3601 Control whether to automatically flush the software-managed cache
3602 during Cell/B.E. debugging.
3604 set sh calling-convention
3605 show sh calling-convention
3606 Control the calling convention used when calling SH target functions.
3609 show debug timestamp
3610 Control display of timestamps with GDB debugging output.
3612 set disassemble-next-line
3613 show disassemble-next-line
3614 Control display of disassembled source lines or instructions when
3617 set remote noack-packet
3618 show remote noack-packet
3619 Set/show the use of remote protocol QStartNoAckMode packet. See above
3620 under "New remote packets."
3622 set remote query-attached-packet
3623 show remote query-attached-packet
3624 Control use of remote protocol `qAttached' (query-attached) packet.
3626 set remote read-siginfo-object
3627 show remote read-siginfo-object
3628 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3631 set remote write-siginfo-object
3632 show remote write-siginfo-object
3633 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3636 set remote reverse-continue
3637 show remote reverse-continue
3638 Control use of remote protocol 'bc' (reverse-continue) packet.
3640 set remote reverse-step
3641 show remote reverse-step
3642 Control use of remote protocol 'bs' (reverse-step) packet.
3644 set displaced-stepping
3645 show displaced-stepping
3646 Control displaced stepping mode. Displaced stepping is a way to
3647 single-step over breakpoints without removing them from the debuggee.
3648 Also known as "out-of-line single-stepping".
3651 show debug displaced
3652 Control display of debugging info for displaced stepping.
3654 maint set internal-error
3655 maint show internal-error
3656 Control what GDB does when an internal error is detected.
3658 maint set internal-warning
3659 maint show internal-warning
3660 Control what GDB does when an internal warning is detected.
3665 Use a wrapper program to launch programs for debugging.
3667 set multiple-symbols (all|ask|cancel)
3668 show multiple-symbols
3669 The value of this variable can be changed to adjust the debugger behavior
3670 when an expression or a breakpoint location contains an ambiguous symbol
3671 name (an overloaded function name, for instance).
3673 set breakpoint always-inserted
3674 show breakpoint always-inserted
3675 Keep breakpoints always inserted in the target, as opposed to inserting
3676 them when resuming the target, and removing them when the target stops.
3677 This option can improve debugger performance on slow remote targets.
3679 set arm fallback-mode (arm|thumb|auto)
3680 show arm fallback-mode
3681 set arm force-mode (arm|thumb|auto)
3683 These commands control how ARM GDB determines whether instructions
3684 are ARM or Thumb. The default for both settings is auto, which uses
3685 the current CPSR value for instructions without symbols; previous
3686 versions of GDB behaved as if "set arm fallback-mode arm".
3688 set disable-randomization
3689 show disable-randomization
3690 Standalone programs run with the virtual address space randomization enabled
3691 by default on some platforms. This option keeps the addresses stable across
3692 multiple debugging sessions.
3696 Control whether other threads are stopped or not when some thread hits
3701 Requests that asynchronous execution is enabled in the target, if available.
3702 In this case, it's possible to resume target in the background, and interact
3703 with GDB while the target is running. "show target-async" displays the
3704 current state of asynchronous execution of the target.
3706 set target-wide-charset
3707 show target-wide-charset
3708 The target-wide-charset is the name of the character set that GDB
3709 uses when printing characters whose type is wchar_t.
3711 set tcp auto-retry (on|off)
3713 set tcp connect-timeout
3714 show tcp connect-timeout
3715 These commands allow GDB to retry failed TCP connections to a remote stub
3716 with a specified timeout period; this is useful if the stub is launched
3717 in parallel with GDB but may not be ready to accept connections immediately.
3719 set libthread-db-search-path
3720 show libthread-db-search-path
3721 Control list of directories which GDB will search for appropriate
3724 set schedule-multiple (on|off)
3725 show schedule-multiple
3726 Allow GDB to resume all threads of all processes or only threads of
3727 the current process.
3731 Use more aggressive caching for accesses to the stack. This improves
3732 performance of remote debugging (particularly backtraces) without
3733 affecting correctness.
3735 set interactive-mode (on|off|auto)
3736 show interactive-mode
3737 Control whether GDB runs in interactive mode (on) or not (off).
3738 When in interactive mode, GDB waits for the user to answer all
3739 queries. Otherwise, GDB does not wait and assumes the default
3740 answer. When set to auto (the default), GDB determines which
3741 mode to use based on the stdin settings.
3746 For program forks, this is replaced by the new more generic `info
3747 inferiors' command. To list checkpoints, you can still use the
3748 `info checkpoints' command, which was an alias for the `info forks'
3752 Replaced by the new `inferior' command. To switch between
3753 checkpoints, you can still use the `restart' command, which was an
3754 alias for the `fork' command.
3757 This is removed, since some targets don't have a notion of
3758 processes. To switch between processes, you can still use the
3759 `inferior' command using GDB's own inferior number.
3762 For program forks, this is replaced by the new more generic `kill
3763 inferior' command. To delete a checkpoint, you can still use the
3764 `delete checkpoint' command, which was an alias for the `delete
3768 For program forks, this is replaced by the new more generic `detach
3769 inferior' command. To detach a checkpoint, you can still use the
3770 `detach checkpoint' command, which was an alias for the `detach
3773 * New native configurations
3775 x86/x86_64 Darwin i[34567]86-*-darwin*
3777 x86_64 MinGW x86_64-*-mingw*
3781 Lattice Mico32 lm32-*
3782 x86 DICOS i[34567]86-*-dicos*
3783 x86_64 DICOS x86_64-*-dicos*
3786 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3787 (mingw32ce) debugging.
3793 These commands were actually not implemented on any target.
3795 *** Changes in GDB 6.8
3797 * New native configurations
3799 NetBSD/hppa hppa*-*netbsd*
3800 Xtensa GNU/Linux xtensa*-*-linux*
3804 NetBSD/hppa hppa*-*-netbsd*
3805 Xtensa GNU/Lunux xtensa*-*-linux*
3807 * Change in command line behavior -- corefiles vs. process ids.
3809 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3810 attaching to process NUMBER fails, GDB no longer attempts to open a
3811 core file named NUMBER. Attaching to a program using the -c option
3812 is no longer supported. Instead, use the '-p' or '--pid' options.
3814 * GDB can now be built as a native debugger for debugging Windows x86
3815 (mingw32) Portable Executable (PE) programs.
3817 * Pending breakpoints no longer change their number when their address
3820 * GDB now supports breakpoints with multiple locations,
3821 including breakpoints on C++ constructors, inside C++ templates,
3822 and in inlined functions.
3824 * GDB's ability to debug optimized code has been improved. GDB more
3825 accurately identifies function bodies and lexical blocks that occupy
3826 more than one contiguous range of addresses.
3828 * Target descriptions can now describe registers for PowerPC.
3830 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3831 registers on PowerPC targets.
3833 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3834 targets even when the libthread_db library is not available.
3836 * The GDB remote stub, gdbserver, now supports the new file transfer
3837 commands (remote put, remote get, and remote delete).
3839 * The GDB remote stub, gdbserver, now supports run and attach in
3840 extended-remote mode.
3842 * hppa*64*-*-hpux11* target broken
3843 The debugger is unable to start a program and fails with the following
3844 error: "Error trying to get information about dynamic linker".
3845 The gdb-6.7 release is also affected.
3847 * GDB now supports the --enable-targets= configure option to allow
3848 building a single GDB executable that supports multiple remote
3849 target architectures.
3851 * GDB now supports debugging C and C++ programs which use the
3852 Decimal Floating Point extension. In addition, the PowerPC target
3853 now has a set of pseudo-registers to inspect decimal float values
3854 stored in two consecutive float registers.
3856 * The -break-insert MI command can optionally create pending
3859 * Improved support for debugging Ada
3860 Many improvements to the Ada language support have been made. These
3862 - Better support for Ada2005 interface types
3863 - Improved handling of arrays and slices in general
3864 - Better support for Taft-amendment types
3865 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3867 - Improved command completion in Ada
3870 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3875 set print frame-arguments (all|scalars|none)
3876 show print frame-arguments
3877 The value of this variable can be changed to control which argument
3878 values should be printed by the debugger when displaying a frame.
3883 Transfer files to and from a remote target, and delete remote files.
3890 Transfer files to and from a remote target, and delete remote files.
3892 * New remote packets
3899 Open, close, read, write, and delete files on the remote system.
3902 Attach to an existing process on the remote system, in extended-remote
3906 Run a new process on the remote system, in extended-remote mode.
3908 *** Changes in GDB 6.7
3910 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3911 bfd, libiberty and opcodes, as revealed by static analysis donated by
3912 Coverity, Inc. (http://scan.coverity.com).
3914 * When looking up multiply-defined global symbols, GDB will now prefer the
3915 symbol definition in the current shared library if it was built using the
3916 -Bsymbolic linker option.
3918 * When the Text User Interface (TUI) is not configured, GDB will now
3919 recognize the -tui command-line option and print a message that the TUI
3922 * The GDB remote stub, gdbserver, now has lower overhead for high
3923 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3925 * GDB for MIPS targets now autodetects whether a remote target provides
3926 32-bit or 64-bit register values.
3928 * Support for C++ member pointers has been improved.
3930 * GDB now understands XML target descriptions, which specify the
3931 target's overall architecture. GDB can read a description from
3932 a local file or over the remote serial protocol.
3934 * Vectors of single-byte data use a new integer type which is not
3935 automatically displayed as character or string data.
3937 * The /s format now works with the print command. It displays
3938 arrays of single-byte integers and pointers to single-byte integers
3941 * Target descriptions can now describe target-specific registers,
3942 for architectures which have implemented the support (currently
3943 only ARM, M68K, and MIPS).
3945 * GDB and the GDB remote stub, gdbserver, now support the XScale
3948 * The GDB remote stub, gdbserver, has been updated to support
3949 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3950 has been rewritten to use the standard GDB remote protocol.
3952 * GDB can now step into C++ functions which are called through thunks.
3954 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3956 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3957 layout. It also supports a TextSeg= and DataSeg= response when only
3958 segment base addresses (rather than offsets) are available.
3960 * The /i format now outputs any trailing branch delay slot instructions
3961 immediately following the last instruction within the count specified.
3963 * The GDB remote protocol "T" stop reply packet now supports a
3964 "library" response. Combined with the new "qXfer:libraries:read"
3965 packet, this response allows GDB to debug shared libraries on targets
3966 where the operating system manages the list of loaded libraries (e.g.
3967 Windows and SymbianOS).
3969 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3970 (DLLs) on Windows and Windows CE targets.
3972 * GDB now supports a faster verification that a .debug file matches its binary
3973 according to its build-id signature, if the signature is present.
3979 Enable or disable hardware flow control (RTS/CTS) on the serial port
3980 when debugging using remote targets.
3982 set mem inaccessible-by-default
3983 show mem inaccessible-by-default
3984 If the target supplies a memory map, for instance via the remote
3985 protocol's "qXfer:memory-map:read" packet, setting this variable
3986 prevents GDB from accessing memory outside the memory map. This
3987 is useful for targets with memory mapped registers or which react
3988 badly to accesses of unmapped address space.
3990 set breakpoint auto-hw
3991 show breakpoint auto-hw
3992 If the target supplies a memory map, for instance via the remote
3993 protocol's "qXfer:memory-map:read" packet, setting this variable
3994 lets GDB use hardware breakpoints automatically for memory regions
3995 where it can not use software breakpoints. This covers both the
3996 "break" command and internal breakpoints used for other commands
3997 including "next" and "finish".
4000 catch exception unhandled
4001 Stop the program execution when Ada exceptions are raised.
4004 Stop the program execution when an Ada assertion failed.
4008 Set an alternate system root for target files. This is a more
4009 general version of "set solib-absolute-prefix", which is now
4010 an alias to "set sysroot".
4013 Provide extended SPU facility status information. This set of
4014 commands is available only when debugging the Cell/B.E. SPU
4017 * New native configurations
4019 OpenBSD/sh sh*-*openbsd*
4022 unset tdesc filename
4024 Use the specified local file as an XML target description, and do
4025 not query the target for its built-in description.
4029 OpenBSD/sh sh*-*-openbsd*
4030 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4031 Toshiba Media Processor mep-elf
4033 * New remote packets
4036 Ignore the specified signals; pass them directly to the debugged program
4037 without stopping other threads or reporting them to GDB.
4039 qXfer:features:read:
4040 Read an XML target description from the target, which describes its
4045 Read or write contents of an spufs file on the target system. These
4046 packets are available only on the Cell/B.E. SPU architecture.
4048 qXfer:libraries:read:
4049 Report the loaded shared libraries. Combined with new "T" packet
4050 response, this packet allows GDB to debug shared libraries on
4051 targets where the operating system manages the list of loaded
4052 libraries (e.g. Windows and SymbianOS).
4056 Support for these obsolete configurations has been removed.
4064 i[34567]86-*-lynxos*
4065 i[34567]86-*-netware*
4066 i[34567]86-*-sco3.2v5*
4067 i[34567]86-*-sco3.2v4*
4069 i[34567]86-*-sysv4.2*
4072 i[34567]86-*-unixware2*
4073 i[34567]86-*-unixware*
4082 * Other removed features
4089 Various m68k-only ROM monitors.
4096 Various Renesas ROM monitors and debugging interfaces for SH and
4101 Support for a Macraigor serial interface to on-chip debugging.
4102 GDB does not directly support the newer parallel or USB
4107 A debug information format. The predecessor to DWARF 2 and
4108 DWARF 3, which are still supported.
4110 Support for the HP aCC compiler on HP-UX/PA-RISC
4112 SOM-encapsulated symbolic debugging information, automatic
4113 invocation of pxdb, and the aCC custom C++ ABI. This does not
4114 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4115 with aCC can still be debugged on an assembly level.
4117 MIPS ".pdr" sections
4119 A MIPS-specific format used to describe stack frame layout
4120 in debugging information.
4124 GDB could work with an older version of Guile to debug
4125 the interpreter and Scheme programs running in it.
4127 set mips stack-arg-size
4128 set mips saved-gpreg-size
4130 Use "set mips abi" to control parameter passing for MIPS.
4132 *** Changes in GDB 6.6
4137 Cell Broadband Engine SPU spu-elf
4139 * GDB can now be configured as a cross-debugger targeting native Windows
4140 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4141 running on a Windows system over TCP/IP to debug Windows programs.
4143 * The GDB remote stub, gdbserver, has been updated to support Windows and
4144 Cygwin debugging. Both single-threaded and multi-threaded programs are
4147 * The "set trust-readonly-sections" command works again. This command was
4148 broken in GDB 6.3, 6.4, and 6.5.
4150 * The "load" command now supports writing to flash memory, if the remote
4151 stub provides the required support.
4153 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4154 longer requires symbolic debug information (e.g. DWARF-2).
4159 unset substitute-path
4160 show substitute-path
4161 Manage a list of substitution rules that GDB uses to rewrite the name
4162 of the directories where the sources are located. This can be useful
4163 for instance when the sources were moved to a different location
4164 between compilation and debugging.
4168 Print each CLI command as it is executed. Each command is prefixed with
4169 a number of `+' symbols representing the nesting depth.
4170 The source command now has a `-v' option to enable the same feature.
4174 The ARM Demon monitor support (RDP protocol, "target rdp").
4176 Kernel Object Display, an embedded debugging feature which only worked with
4177 an obsolete version of Cisco IOS.
4179 The 'set download-write-size' and 'show download-write-size' commands.
4181 * New remote packets
4184 Tell a stub about GDB client features, and request remote target features.
4185 The first feature implemented is PacketSize, which allows the target to
4186 specify the size of packets it can handle - to minimize the number of
4187 packets required and improve performance when connected to a remote
4191 Fetch an OS auxilliary vector from the remote stub. This packet is a
4192 more efficient replacement for qPart:auxv:read.
4194 qXfer:memory-map:read:
4195 Fetch a memory map from the remote stub, including information about
4196 RAM, ROM, and flash memory devices.
4201 Erase and program a flash memory device.
4203 * Removed remote packets
4206 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4207 used it, and only gdbserver implemented it.
4209 *** Changes in GDB 6.5
4213 Renesas M32C/M16C m32c-elf
4215 Morpho Technologies ms1 ms1-elf
4219 init-if-undefined Initialize a convenience variable, but
4220 only if it doesn't already have a value.
4222 The following commands are presently only implemented for native GNU/Linux:
4224 checkpoint Save a snapshot of the program state.
4226 restart <n> Return the program state to a
4227 previously saved state.
4229 info checkpoints List currently saved checkpoints.
4231 delete-checkpoint <n> Delete a previously saved checkpoint.
4233 set|show detach-on-fork Tell gdb whether to detach from a newly
4234 forked process, or to keep debugging it.
4236 info forks List forks of the user program that
4237 are available to be debugged.
4239 fork <n> Switch to debugging one of several
4240 forks of the user program that are
4241 available to be debugged.
4243 delete-fork <n> Delete a fork from the list of forks
4244 that are available to be debugged (and
4245 kill the forked process).
4247 detach-fork <n> Delete a fork from the list of forks
4248 that are available to be debugged (and
4249 allow the process to continue).
4253 Morpho Technologies ms2 ms1-elf
4255 * Improved Windows host support
4257 GDB now builds as a cross debugger hosted on i686-mingw32, including
4258 native console support, and remote communications using either
4259 network sockets or serial ports.
4261 * Improved Modula-2 language support
4263 GDB can now print most types in the Modula-2 syntax. This includes:
4264 basic types, set types, record types, enumerated types, range types,
4265 pointer types and ARRAY types. Procedure var parameters are correctly
4266 printed and hexadecimal addresses and character constants are also
4267 written in the Modula-2 syntax. Best results can be obtained by using
4268 GNU Modula-2 together with the -gdwarf-2 command line option.
4272 The ARM rdi-share module.
4274 The Netware NLM debug server.
4276 *** Changes in GDB 6.4
4278 * New native configurations
4280 OpenBSD/arm arm*-*-openbsd*
4281 OpenBSD/mips64 mips64-*-openbsd*
4285 Morpho Technologies ms1 ms1-elf
4287 * New command line options
4289 --batch-silent As for --batch, but totally silent.
4290 --return-child-result The debugger will exist with the same value
4291 the child (debugged) program exited with.
4292 --eval-command COMMAND, -ex COMMAND
4293 Execute a single GDB CLI command. This may be
4294 specified multiple times and in conjunction
4295 with the --command (-x) option.
4297 * Deprecated commands removed
4299 The following commands, that were deprecated in 2000, have been
4303 set|show arm disassembly-flavor set|show arm disassembler
4304 othernames set arm disassembler
4305 set|show remotedebug set|show debug remote
4306 set|show archdebug set|show debug arch
4307 set|show eventdebug set|show debug event
4310 * New BSD user-level threads support
4312 It is now possible to debug programs using the user-level threads
4313 library on OpenBSD and FreeBSD. Currently supported (target)
4316 FreeBSD/amd64 x86_64-*-freebsd*
4317 FreeBSD/i386 i386-*-freebsd*
4318 OpenBSD/i386 i386-*-openbsd*
4320 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4321 are not yet supported.
4323 * New support for Matsushita MN10300 w/sim added
4324 (Work in progress). mn10300-elf.
4326 * REMOVED configurations and files
4328 VxWorks and the XDR protocol *-*-vxworks
4329 Motorola MCORE mcore-*-*
4330 National Semiconductor NS32000 ns32k-*-*
4332 * New "set print array-indexes" command
4334 After turning this setting "on", GDB prints the index of each element
4335 when displaying arrays. The default is "off" to preserve the previous
4338 * VAX floating point support
4340 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4342 * User-defined command support
4344 In addition to using $arg0..$arg9 for argument passing, it is now possible
4345 to use $argc to determine now many arguments have been passed. See the
4346 section on user-defined commands in the user manual for more information.
4348 *** Changes in GDB 6.3:
4350 * New command line option
4352 GDB now accepts -l followed by a number to set the timeout for remote
4355 * GDB works with GCC -feliminate-dwarf2-dups
4357 GDB now supports a more compact representation of DWARF-2 debug
4358 information using DW_FORM_ref_addr references. These are produced
4359 by GCC with the option -feliminate-dwarf2-dups and also by some
4360 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4361 to use -feliminate-dwarf2-dups.
4363 * Internationalization
4365 When supported by the host system, GDB will be built with
4366 internationalization (libintl). The task of marking up the sources is
4367 continued, we're looking forward to our first translation.
4371 Initial support for debugging programs compiled with the GNAT
4372 implementation of the Ada programming language has been integrated
4373 into GDB. In this release, support is limited to expression evaluation.
4375 * New native configurations
4377 GNU/Linux/m32r m32r-*-linux-gnu
4381 GDB's remote protocol now includes support for the 'p' packet. This
4382 packet is used to fetch individual registers from a remote inferior.
4384 * END-OF-LIFE registers[] compatibility module
4386 GDB's internal register infrastructure has been completely rewritten.
4387 The new infrastructure making possible the implementation of key new
4388 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4391 GDB 6.3 will be the last release to include the the registers[]
4392 compatibility module that allowed out-of-date configurations to
4393 continue to work. This change directly impacts the following
4403 powerpc bdm protocol
4405 Unless there is activity to revive these configurations, they will be
4406 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4408 * OBSOLETE configurations and files
4410 Configurations that have been declared obsolete in this release have
4411 been commented out. Unless there is activity to revive these
4412 configurations, the next release of GDB will have their sources
4413 permanently REMOVED.
4422 *** Changes in GDB 6.2.1:
4424 * MIPS `break main; run' gave an heuristic-fence-post warning
4426 When attempting to run even a simple program, a warning about
4427 heuristic-fence-post being hit would be reported. This problem has
4430 * MIPS IRIX 'long double' crashed GDB
4432 When examining a long double variable, GDB would get a segmentation
4433 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4434 IRIX long double values).
4438 A bug in the VAX stack code was causing problems with the "next"
4439 command. This problem has been fixed.
4441 *** Changes in GDB 6.2:
4443 * Fix for ``many threads''
4445 On GNU/Linux systems that use the NPTL threads library, a program
4446 rapidly creating and deleting threads would confuse GDB leading to the
4449 ptrace: No such process.
4450 thread_db_get_info: cannot get thread info: generic error
4452 This problem has been fixed.
4454 * "-async" and "-noasync" options removed.
4456 Support for the broken "-noasync" option has been removed (it caused
4459 * New ``start'' command.
4461 This command runs the program until the begining of the main procedure.
4463 * New BSD Kernel Data Access Library (libkvm) interface
4465 Using ``target kvm'' it is now possible to debug kernel core dumps and
4466 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4467 platforms. Currently supported (native-only) configurations are:
4469 FreeBSD/amd64 x86_64-*-freebsd*
4470 FreeBSD/i386 i?86-*-freebsd*
4471 NetBSD/i386 i?86-*-netbsd*
4472 NetBSD/m68k m68*-*-netbsd*
4473 NetBSD/sparc sparc-*-netbsd*
4474 OpenBSD/amd64 x86_64-*-openbsd*
4475 OpenBSD/i386 i?86-*-openbsd*
4476 OpenBSD/m68k m68*-openbsd*
4477 OpenBSD/sparc sparc-*-openbsd*
4479 * Signal trampoline code overhauled
4481 Many generic problems with GDB's signal handling code have been fixed.
4482 These include: backtraces through non-contiguous stacks; recognition
4483 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4484 call; backtrace through a signal trampoline; step into and out of
4485 signal handlers; and single-stepping in the signal trampoline.
4487 Please note that kernel bugs are a limiting factor here. These
4488 features have been shown to work on an s390 GNU/Linux system that
4489 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4491 * Cygwin support for DWARF 2 added.
4493 * New native configurations
4495 GNU/Linux/hppa hppa*-*-linux*
4496 OpenBSD/hppa hppa*-*-openbsd*
4497 OpenBSD/m68k m68*-*-openbsd*
4498 OpenBSD/m88k m88*-*-openbsd*
4499 OpenBSD/powerpc powerpc-*-openbsd*
4500 NetBSD/vax vax-*-netbsd*
4501 OpenBSD/vax vax-*-openbsd*
4503 * END-OF-LIFE frame compatibility module
4505 GDB's internal frame infrastructure has been completely rewritten.
4506 The new infrastructure making it possible to support key new features
4507 including DWARF 2 Call Frame Information. To aid in the task of
4508 migrating old configurations to this new infrastructure, a
4509 compatibility module, that allowed old configurations to continue to
4510 work, was also included.
4512 GDB 6.2 will be the last release to include this frame compatibility
4513 module. This change directly impacts the following configurations:
4523 Unless there is activity to revive these configurations, they will be
4524 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4526 * REMOVED configurations and files
4528 Sun 3, running SunOS 3 m68*-*-sunos3*
4529 Sun 3, running SunOS 4 m68*-*-sunos4*
4530 Sun 2, running SunOS 3 m68000-*-sunos3*
4531 Sun 2, running SunOS 4 m68000-*-sunos4*
4532 Motorola 680x0 running LynxOS m68*-*-lynxos*
4533 AT&T 3b1/Unix pc m68*-att-*
4534 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4535 decstation mips-dec-* mips-little-*
4536 riscos mips-*-riscos* mips-*-sysv*
4537 sonymips mips-sony-*
4538 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4540 *** Changes in GDB 6.1.1:
4542 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4544 The TUI (Text-mode User Interface) is now built as part of a default
4545 GDB configuration. It is enabled by either selecting the TUI with the
4546 command line option "-i=tui" or by running the separate "gdbtui"
4547 program. For more information on the TUI, see the manual "Debugging
4550 * Pending breakpoint support (also included in GDB 6.1)
4552 Support has been added to allow you to specify breakpoints in shared
4553 libraries that have not yet been loaded. If a breakpoint location
4554 cannot be found, and the "breakpoint pending" option is set to auto,
4555 GDB queries you if you wish to make the breakpoint pending on a future
4556 shared-library load. If and when GDB resolves the breakpoint symbol,
4557 the pending breakpoint is removed as one or more regular breakpoints
4560 Pending breakpoints are very useful for GCJ Java debugging.
4562 * Fixed ISO-C build problems
4564 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4565 non ISO-C code that stopped them being built using a more strict ISO-C
4566 compiler (e.g., IBM's C compiler).
4568 * Fixed build problem on IRIX 5
4570 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4571 wasn't able to compile compile on an IRIX 5 system.
4573 * Added execute permission to gdb/gdbserver/configure
4575 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4576 permission. This bug would cause configure to fail on a number of
4577 systems (Solaris, IRIX). Ref: server/519.
4579 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4581 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4582 has been updated to use constant array sizes.
4584 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4586 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4587 its generated DWARF Call Frame Info. This encoding was causing GDB to
4588 panic, that panic has been fixed. Ref: gdb/1628.
4590 * Fixed a problem when examining parameters in shared library code.
4592 When examining parameters in optimized shared library code generated
4593 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4594 not available''. GDB now correctly displays the variable's value.
4596 *** Changes in GDB 6.1:
4598 * Removed --with-mmalloc
4600 Support for the mmalloc memory manager has been removed, as it
4601 conflicted with the internal gdb byte cache.
4603 * Changes in AMD64 configurations
4605 The AMD64 target now includes the %cs and %ss registers. As a result
4606 the AMD64 remote protocol has changed; this affects the floating-point
4607 and SSE registers. If you rely on those registers for your debugging,
4608 you should upgrade gdbserver on the remote side.
4610 * Revised SPARC target
4612 The SPARC target has been completely revised, incorporating the
4613 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4614 support for LynxOS and SunOS 4 has been dropped. Calling functions
4615 from within GDB on operating systems with a non-executable stack
4616 (Solaris, OpenBSD) now works.
4620 GDB has a new C++ demangler which does a better job on the mangled
4621 names generated by current versions of g++. It also runs faster, so
4622 with this and other changes gdb should now start faster on large C++
4625 * DWARF 2 Location Expressions
4627 GDB support for location expressions has been extended to support function
4628 arguments and frame bases. Older versions of GDB could crash when they
4631 * C++ nested types and namespaces
4633 GDB's support for nested types and namespaces in C++ has been
4634 improved, especially if you use the DWARF 2 debugging format. (This
4635 is the default for recent versions of GCC on most platforms.)
4636 Specifically, if you have a class "Inner" defined within a class or
4637 namespace "Outer", then GDB realizes that the class's name is
4638 "Outer::Inner", not simply "Inner". This should greatly reduce the
4639 frequency of complaints about not finding RTTI symbols. In addition,
4640 if you are stopped at inside of a function defined within a namespace,
4641 GDB modifies its name lookup accordingly.
4643 * New native configurations
4645 NetBSD/amd64 x86_64-*-netbsd*
4646 OpenBSD/amd64 x86_64-*-openbsd*
4647 OpenBSD/alpha alpha*-*-openbsd*
4648 OpenBSD/sparc sparc-*-openbsd*
4649 OpenBSD/sparc64 sparc64-*-openbsd*
4651 * New debugging protocols
4653 M32R with SDI protocol m32r-*-elf*
4655 * "set prompt-escape-char" command deleted.
4657 The command "set prompt-escape-char" has been deleted. This command,
4658 and its very obscure effet on GDB's prompt, was never documented,
4659 tested, nor mentioned in the NEWS file.
4661 * OBSOLETE configurations and files
4663 Configurations that have been declared obsolete in this release have
4664 been commented out. Unless there is activity to revive these
4665 configurations, the next release of GDB will have their sources
4666 permanently REMOVED.
4668 Sun 3, running SunOS 3 m68*-*-sunos3*
4669 Sun 3, running SunOS 4 m68*-*-sunos4*
4670 Sun 2, running SunOS 3 m68000-*-sunos3*
4671 Sun 2, running SunOS 4 m68000-*-sunos4*
4672 Motorola 680x0 running LynxOS m68*-*-lynxos*
4673 AT&T 3b1/Unix pc m68*-att-*
4674 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4675 decstation mips-dec-* mips-little-*
4676 riscos mips-*-riscos* mips-*-sysv*
4677 sonymips mips-sony-*
4678 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4680 * REMOVED configurations and files
4682 SGI Irix-4.x mips-sgi-irix4 or iris4
4683 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4684 Z8000 simulator z8k-zilog-none or z8ksim
4685 Matsushita MN10200 w/simulator mn10200-*-*
4686 H8/500 simulator h8500-hitachi-hms or h8500hms
4687 HP/PA running BSD hppa*-*-bsd*
4688 HP/PA running OSF/1 hppa*-*-osf*
4689 HP/PA Pro target hppa*-*-pro*
4690 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4691 386BSD i[3456]86-*-bsd*
4692 Sequent family i[3456]86-sequent-sysv4*
4693 i[3456]86-sequent-sysv*
4694 i[3456]86-sequent-bsd*
4695 SPARC running LynxOS sparc-*-lynxos*
4696 SPARC running SunOS 4 sparc-*-sunos4*
4697 Tsqware Sparclet sparclet-*-*
4698 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4700 *** Changes in GDB 6.0:
4704 Support for debugging the Objective-C programming language has been
4705 integrated into GDB.
4707 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4709 DWARF 2's Call Frame Information makes available compiler generated
4710 information that more exactly describes the program's run-time stack.
4711 By using this information, GDB is able to provide more robust stack
4714 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4715 have been updated to use a new backtrace mechanism which includes
4716 DWARF 2 CFI support.
4720 GDB's remote protocol has been extended to include support for hosted
4721 file I/O (where the remote target uses GDB's file system). See GDB's
4722 remote protocol documentation for details.
4724 * All targets using the new architecture framework.
4726 All of GDB's targets have been updated to use the new internal
4727 architecture framework. The way is now open for future GDB releases
4728 to include cross-architecture native debugging support (i386 on amd64,
4731 * GNU/Linux's Thread Local Storage (TLS)
4733 GDB now includes support for for the GNU/Linux implementation of
4734 per-thread variables.
4736 * GNU/Linux's Native POSIX Thread Library (NPTL)
4738 GDB's thread code has been updated to work with either the new
4739 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4741 * Separate debug info.
4743 GDB, in conjunction with BINUTILS, now supports a mechanism for
4744 automatically loading debug information from a separate file. Instead
4745 of shipping full debug and non-debug versions of system libraries,
4746 system integrators can now instead ship just the stripped libraries
4747 and optional debug files.
4749 * DWARF 2 Location Expressions
4751 DWARF 2 Location Expressions allow the compiler to more completely
4752 describe the location of variables (even in optimized code) to the
4755 GDB now includes preliminary support for location expressions (support
4756 for DW_OP_piece is still missing).
4760 A number of long standing bugs that caused GDB to die while starting a
4761 Java application have been fixed. GDB's Java support is now
4762 considered "useable".
4764 * GNU/Linux support for fork, vfork, and exec.
4766 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4767 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4770 * GDB supports logging output to a file
4772 There are two new commands, "set logging" and "show logging", which can be
4773 used to capture GDB's output to a file.
4775 * The meaning of "detach" has changed for gdbserver
4777 The "detach" command will now resume the application, as documented. To
4778 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4781 * d10v, m68hc11 `regs' command deprecated
4783 The `info registers' command has been updated so that it displays the
4784 registers using a format identical to the old `regs' command.
4788 A new command, "maint set profile on/off", has been added. This command can
4789 be used to enable or disable profiling while running GDB, to profile a
4790 session or a set of commands. In addition there is a new configure switch,
4791 "--enable-profiling", which will cause GDB to be compiled with profiling
4792 data, for more informative profiling results.
4794 * Default MI syntax changed to "mi2".
4796 The default MI (machine interface) syntax, enabled by the command line
4797 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4798 "mi1", can be enabled by specifying the option "-i=mi1".
4800 Support for the original "mi0" syntax (included in GDB 5.0) has been
4803 Fix for gdb/192: removed extraneous space when displaying frame level.
4804 Fix for gdb/672: update changelist is now output in mi list format.
4805 Fix for gdb/702: a -var-assign that updates the value now shows up
4806 in a subsequent -var-update.
4808 * New native configurations.
4810 FreeBSD/amd64 x86_64-*-freebsd*
4812 * Multi-arched targets.
4814 HP/PA HPUX11 hppa*-*-hpux*
4815 Renesas M32R/D w/simulator m32r-*-elf*
4817 * OBSOLETE configurations and files
4819 Configurations that have been declared obsolete in this release have
4820 been commented out. Unless there is activity to revive these
4821 configurations, the next release of GDB will have their sources
4822 permanently REMOVED.
4824 Z8000 simulator z8k-zilog-none or z8ksim
4825 Matsushita MN10200 w/simulator mn10200-*-*
4826 H8/500 simulator h8500-hitachi-hms or h8500hms
4827 HP/PA running BSD hppa*-*-bsd*
4828 HP/PA running OSF/1 hppa*-*-osf*
4829 HP/PA Pro target hppa*-*-pro*
4830 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4831 Sequent family i[3456]86-sequent-sysv4*
4832 i[3456]86-sequent-sysv*
4833 i[3456]86-sequent-bsd*
4834 Tsqware Sparclet sparclet-*-*
4835 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4837 * REMOVED configurations and files
4840 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4841 IBM AIX PS/2 i[3456]86-*-aix
4842 i386 running Mach 3.0 i[3456]86-*-mach3*
4843 i386 running Mach i[3456]86-*-mach*
4844 i386 running OSF/1 i[3456]86-*osf1mk*
4845 HP/Apollo 68k Family m68*-apollo*-sysv*,
4847 m68*-hp-bsd*, m68*-hp-hpux*
4848 Argonaut Risc Chip (ARC) arc-*-*
4849 Mitsubishi D30V d30v-*-*
4850 Fujitsu FR30 fr30-*-elf*
4851 OS/9000 i[34]86-*-os9k
4852 I960 with MON960 i960-*-coff
4854 * MIPS $fp behavior changed
4856 The convenience variable $fp, for the MIPS, now consistently returns
4857 the address of the current frame's base. Previously, depending on the
4858 context, $fp could refer to either $sp or the current frame's base
4859 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4860 The GNU Source-Level Debugger''.
4862 *** Changes in GDB 5.3:
4864 * GNU/Linux shared library multi-threaded performance improved.
4866 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4867 `/proc', in preference to `ptrace' for memory reads. This may result
4868 in an improvement in the start-up time of multi-threaded, shared
4869 library applications when run under GDB. One GDB user writes: ``loads
4870 shared libs like mad''.
4872 * ``gdbserver'' now supports multi-threaded applications on some targets
4874 Support for debugging multi-threaded applications which use
4875 the GNU/Linux LinuxThreads package has been added for
4876 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4877 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4879 * GDB now supports C/C++ preprocessor macros.
4881 GDB now expands preprocessor macro invocations in C/C++ expressions,
4882 and provides various commands for showing macro definitions and how
4885 The new command `macro expand EXPRESSION' expands any macro
4886 invocations in expression, and shows the result.
4888 The new command `show macro MACRO-NAME' shows the definition of the
4889 macro named MACRO-NAME, and where it was defined.
4891 Most compilers don't include information about macros in the debugging
4892 information by default. In GCC 3.1, for example, you need to compile
4893 your program with the options `-gdwarf-2 -g3'. If the macro
4894 information is present in the executable, GDB will read it.
4896 * Multi-arched targets.
4898 DEC Alpha (partial) alpha*-*-*
4899 DEC VAX (partial) vax-*-*
4901 National Semiconductor NS32000 (partial) ns32k-*-*
4902 Motorola 68000 (partial) m68k-*-*
4903 Motorola MCORE mcore-*-*
4907 Fujitsu FRV architecture added by Red Hat frv*-*-*
4910 * New native configurations
4912 Alpha NetBSD alpha*-*-netbsd*
4913 SH NetBSD sh*-*-netbsdelf*
4914 MIPS NetBSD mips*-*-netbsd*
4915 UltraSPARC NetBSD sparc64-*-netbsd*
4917 * OBSOLETE configurations and files
4919 Configurations that have been declared obsolete in this release have
4920 been commented out. Unless there is activity to revive these
4921 configurations, the next release of GDB will have their sources
4922 permanently REMOVED.
4924 Mitsubishi D30V d30v-*-*
4925 OS/9000 i[34]86-*-os9k
4926 IBM AIX PS/2 i[3456]86-*-aix
4927 Fujitsu FR30 fr30-*-elf*
4928 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4929 Argonaut Risc Chip (ARC) arc-*-*
4930 i386 running Mach 3.0 i[3456]86-*-mach3*
4931 i386 running Mach i[3456]86-*-mach*
4932 i386 running OSF/1 i[3456]86-*osf1mk*
4933 HP/Apollo 68k Family m68*-apollo*-sysv*,
4935 m68*-hp-bsd*, m68*-hp-hpux*
4936 I960 with MON960 i960-*-coff
4938 * OBSOLETE languages
4940 CHILL, a Pascal like language used by telecommunications companies.
4942 * REMOVED configurations and files
4944 AMD 29k family via UDI a29k-amd-udi, udi29k
4945 A29K VxWorks a29k-*-vxworks
4946 AMD 29000 embedded, using EBMON a29k-none-none
4947 AMD 29000 embedded with COFF a29k-none-coff
4948 AMD 29000 embedded with a.out a29k-none-aout
4950 testsuite/gdb.hp/gdb.threads-hp/ directory
4952 * New command "set max-user-call-depth <nnn>"
4954 This command allows the user to limit the call depth of user-defined
4955 commands. The default is 1024.
4957 * Changes in FreeBSD/i386 native debugging.
4959 Support for the "generate-core-file" has been added.
4961 * New commands "dump", "append", and "restore".
4963 These commands allow data to be copied from target memory
4964 to a bfd-format or binary file (dump and append), and back
4965 from a file into memory (restore).
4967 * Improved "next/step" support on multi-processor Alpha Tru64.
4969 The previous single-step mechanism could cause unpredictable problems,
4970 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4971 of a software single-step mechanism prevents this.
4973 *** Changes in GDB 5.2.1:
4981 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4982 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4983 Fix, by Joel Brobecker imported from mainline.
4985 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4986 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4987 Fix, by Fred Fish, imported from mainline.
4989 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4990 Surprisingly enough, it works now.
4991 By Michal Ludvig, imported from mainline.
4993 i386 hardware watchpoint support:
4994 avoid misses on second run for some targets.
4995 By Pierre Muller, imported from mainline.
4997 *** Changes in GDB 5.2:
4999 * New command "set trust-readonly-sections on[off]".
5001 This command is a hint that tells gdb that read-only sections
5002 really are read-only (ie. that their contents will not change).
5003 In this mode, gdb will go to the object file rather than the
5004 target to read memory from read-only sections (such as ".text").
5005 This can be a significant performance improvement on some
5006 (notably embedded) targets.
5008 * New command "generate-core-file" (or "gcore").
5010 This new gdb command allows the user to drop a core file of the child
5011 process state at any time. So far it's been implemented only for
5012 GNU/Linux and Solaris, but should be relatively easily ported to other
5013 hosts. Argument is core file name (defaults to core.<pid>).
5015 * New command line option
5017 GDB now accepts --pid or -p followed by a process id.
5019 * Change in command line behavior -- corefiles vs. process ids.
5021 There is a subtle behavior in the way in which GDB handles
5022 command line arguments. The first non-flag argument is always
5023 a program to debug, but the second non-flag argument may either
5024 be a corefile or a process id. Previously, GDB would attempt to
5025 open the second argument as a corefile, and if that failed, would
5026 issue a superfluous error message and then attempt to attach it as
5027 a process. Now, if the second argument begins with a non-digit,
5028 it will be treated as a corefile. If it begins with a digit,
5029 GDB will attempt to attach it as a process, and if no such process
5030 is found, will then attempt to open it as a corefile.
5032 * Changes in ARM configurations.
5034 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5035 configuration is fully multi-arch.
5037 * New native configurations
5039 ARM NetBSD arm*-*-netbsd*
5040 x86 OpenBSD i[3456]86-*-openbsd*
5041 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5042 Sparc64 running FreeBSD sparc64-*-freebsd*
5046 Sanyo XStormy16 xstormy16-elf
5048 * OBSOLETE configurations and files
5050 Configurations that have been declared obsolete in this release have
5051 been commented out. Unless there is activity to revive these
5052 configurations, the next release of GDB will have their sources
5053 permanently REMOVED.
5055 AMD 29k family via UDI a29k-amd-udi, udi29k
5056 A29K VxWorks a29k-*-vxworks
5057 AMD 29000 embedded, using EBMON a29k-none-none
5058 AMD 29000 embedded with COFF a29k-none-coff
5059 AMD 29000 embedded with a.out a29k-none-aout
5061 testsuite/gdb.hp/gdb.threads-hp/ directory
5063 * REMOVED configurations and files
5065 TI TMS320C80 tic80-*-*
5067 PowerPC Solaris powerpcle-*-solaris*
5068 PowerPC Windows NT powerpcle-*-cygwin32
5069 PowerPC Netware powerpc-*-netware*
5070 Harris/CXUX m88k m88*-harris-cxux*
5071 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5072 ns32k-utek-sysv* ns32k-utek-*
5073 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5074 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5075 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5076 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5077 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5079 * Changes to command line processing
5081 The new `--args' feature can be used to specify command-line arguments
5082 for the inferior from gdb's command line.
5084 * Changes to key bindings
5086 There is a new `operate-and-get-next' function bound to `C-o'.
5088 *** Changes in GDB 5.1.1
5090 Fix compile problem on DJGPP.
5092 Fix a problem with floating-point registers on the i386 being
5095 Fix to stop GDB crashing on .debug_str debug info.
5097 Numerous documentation fixes.
5099 Numerous testsuite fixes.
5101 *** Changes in GDB 5.1:
5103 * New native configurations
5105 Alpha FreeBSD alpha*-*-freebsd*
5106 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5107 MIPS GNU/Linux mips*-*-linux*
5108 MIPS SGI Irix 6.x mips*-sgi-irix6*
5109 ia64 AIX ia64-*-aix*
5110 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5114 Motorola 68HC11 and 68HC12 m68hc11-elf
5116 UltraSparc running GNU/Linux sparc64-*-linux*
5118 * OBSOLETE configurations and files
5120 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5121 Harris/CXUX m88k m88*-harris-cxux*
5122 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5123 ns32k-utek-sysv* ns32k-utek-*
5124 TI TMS320C80 tic80-*-*
5126 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5127 PowerPC Solaris powerpcle-*-solaris*
5128 PowerPC Windows NT powerpcle-*-cygwin32
5129 PowerPC Netware powerpc-*-netware*
5130 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5131 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5132 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5133 Apple Macintosh (MPW) host N/A
5135 stuff.c (Program to stuff files into a specially prepared space in kdb)
5136 kdb-start.c (Main loop for the standalone kernel debugger)
5138 Configurations that have been declared obsolete in this release have
5139 been commented out. Unless there is activity to revive these
5140 configurations, the next release of GDB will have their sources
5141 permanently REMOVED.
5143 * REMOVED configurations and files
5145 Altos 3068 m68*-altos-*
5146 Convex c1-*-*, c2-*-*
5148 ARM RISCix arm-*-* (as host)
5152 * GDB has been converted to ISO C.
5154 GDB's source code has been converted to ISO C. In particular, the
5155 sources are fully protoized, and rely on standard headers being
5160 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5162 * The MI enabled by default.
5164 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5165 revised and enabled by default. Packages which use GDB as a debugging
5166 engine behind a UI or another front end are encouraged to switch to
5167 using the GDB/MI interface, instead of the old annotations interface
5168 which is now deprecated.
5170 * Support for debugging Pascal programs.
5172 GDB now includes support for debugging Pascal programs. The following
5173 main features are supported:
5175 - Pascal-specific data types such as sets;
5177 - automatic recognition of Pascal sources based on file-name
5180 - Pascal-style display of data types, variables, and functions;
5182 - a Pascal expression parser.
5184 However, some important features are not yet supported.
5186 - Pascal string operations are not supported at all;
5188 - there are some problems with boolean types;
5190 - Pascal type hexadecimal constants are not supported
5191 because they conflict with the internal variables format;
5193 - support for Pascal objects and classes is not full yet;
5195 - unlike Pascal, GDB is case-sensitive for symbol names.
5197 * Changes in completion.
5199 Commands such as `shell', `run' and `set args', which pass arguments
5200 to inferior programs, now complete on file names, similar to what
5201 users expect at the shell prompt.
5203 Commands which accept locations, such as `disassemble', `print',
5204 `breakpoint', `until', etc. now complete on filenames as well as
5205 program symbols. Thus, if you type "break foob TAB", and the source
5206 files linked into the programs include `foobar.c', that file name will
5207 be one of the candidates for completion. However, file names are not
5208 considered for completion after you typed a colon that delimits a file
5209 name from a name of a function in that file, as in "break foo.c:bar".
5211 `set demangle-style' completes on available demangling styles.
5213 * New platform-independent commands:
5215 It is now possible to define a post-hook for a command as well as a
5216 hook that runs before the command. For more details, see the
5217 documentation of `hookpost' in the GDB manual.
5219 * Changes in GNU/Linux native debugging.
5221 Support for debugging multi-threaded programs has been completely
5222 revised for all platforms except m68k and sparc. You can now debug as
5223 many threads as your system allows you to have.
5225 Attach/detach is supported for multi-threaded programs.
5227 Support for SSE registers was added for x86. This doesn't work for
5228 multi-threaded programs though.
5230 * Changes in MIPS configurations.
5232 Multi-arch support is enabled for all MIPS configurations.
5234 GDB can now be built as native debugger on SGI Irix 6.x systems for
5235 debugging n32 executables. (Debugging 64-bit executables is not yet
5238 * Unified support for hardware watchpoints in all x86 configurations.
5240 Most (if not all) native x86 configurations support hardware-assisted
5241 breakpoints and watchpoints in a unified manner. This support
5242 implements debug register sharing between watchpoints, which allows to
5243 put a virtually infinite number of watchpoints on the same address,
5244 and also supports watching regions up to 16 bytes with several debug
5247 The new maintenance command `maintenance show-debug-regs' toggles
5248 debugging print-outs in functions that insert, remove, and test
5249 watchpoints and hardware breakpoints.
5251 * Changes in the DJGPP native configuration.
5253 New command ``info dos sysinfo'' displays assorted information about
5254 the CPU, OS, memory, and DPMI server.
5256 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5257 display information about segment descriptors stored in GDT, LDT, and
5260 New commands ``info dos pde'' and ``info dos pte'' display entries
5261 from Page Directory and Page Tables (for now works with CWSDPMI only).
5262 New command ``info dos address-pte'' displays the Page Table entry for
5263 a given linear address.
5265 GDB can now pass command lines longer than 126 characters to the
5266 program being debugged (requires an update to the libdbg.a library
5267 which is part of the DJGPP development kit).
5269 DWARF2 debug info is now supported.
5271 It is now possible to `step' and `next' through calls to `longjmp'.
5273 * Changes in documentation.
5275 All GDB documentation was converted to GFDL, the GNU Free
5276 Documentation License.
5278 Tracepoints-related commands are now fully documented in the GDB
5281 TUI, the Text-mode User Interface, is now documented in the manual.
5283 Tracepoints-related commands are now fully documented in the GDB
5286 The "GDB Internals" manual now has an index. It also includes
5287 documentation of `ui_out' functions, GDB coding standards, x86
5288 hardware watchpoints, and memory region attributes.
5290 * GDB's version number moved to ``version.in''
5292 The Makefile variable VERSION has been replaced by the file
5293 ``version.in''. People creating GDB distributions should update the
5294 contents of this file.
5298 GUD support is now a standard part of the EMACS distribution.
5300 *** Changes in GDB 5.0:
5302 * Improved support for debugging FP programs on x86 targets
5304 Unified and much-improved support for debugging floating-point
5305 programs on all x86 targets. In particular, ``info float'' now
5306 displays the FP registers in the same format on all x86 targets, with
5307 greater level of detail.
5309 * Improvements and bugfixes in hardware-assisted watchpoints
5311 It is now possible to watch array elements, struct members, and
5312 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5313 on x86 targets no longer erroneously trigger when the address is
5316 * Improvements in the native DJGPP version of GDB
5318 The distribution now includes all the scripts and auxiliary files
5319 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5320 machines ``out of the box''.
5322 The DJGPP version can now debug programs that use signals. It is
5323 possible to catch signals that happened in the debuggee, deliver
5324 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5325 would kill the program being debugged.) Programs that hook hardware
5326 interrupts (keyboard, timer, etc.) can also be debugged.
5328 It is now possible to debug DJGPP programs that redirect their
5329 standard handles or switch them to raw (as opposed to cooked) mode, or
5330 even close them. The command ``run < foo > bar'' works as expected,
5331 and ``info terminal'' reports useful information about the debuggee's
5332 terminal, including raw/cooked mode, redirection, etc.
5334 The DJGPP version now uses termios functions for console I/O, which
5335 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5338 DOS-style file names with drive letters are now fully supported by
5341 It is now possible to debug DJGPP programs that switch their working
5342 directory. It is also possible to rerun the debuggee any number of
5343 times without restarting GDB; thus, you can use the same setup,
5344 breakpoints, etc. for many debugging sessions.
5346 * New native configurations
5348 ARM GNU/Linux arm*-*-linux*
5349 PowerPC GNU/Linux powerpc-*-linux*
5353 Motorola MCore mcore-*-*
5354 x86 VxWorks i[3456]86-*-vxworks*
5355 PowerPC VxWorks powerpc-*-vxworks*
5356 TI TMS320C80 tic80-*-*
5358 * OBSOLETE configurations
5360 Altos 3068 m68*-altos-*
5361 Convex c1-*-*, c2-*-*
5363 ARM RISCix arm-*-* (as host)
5366 Configurations that have been declared obsolete will be commented out,
5367 but the code will be left in place. If there is no activity to revive
5368 these configurations before the next release of GDB, the sources will
5369 be permanently REMOVED.
5371 * Gould support removed
5373 Support for the Gould PowerNode and NP1 has been removed.
5375 * New features for SVR4
5377 On SVR4 native platforms (such as Solaris), if you attach to a process
5378 without first loading a symbol file, GDB will now attempt to locate and
5379 load symbols from the running process's executable file.
5381 * Many C++ enhancements
5383 C++ support has been greatly improved. Overload resolution now works properly
5384 in almost all cases. RTTI support is on the way.
5386 * Remote targets can connect to a sub-program
5388 A popen(3) style serial-device has been added. This device starts a
5389 sub-process (such as a stand-alone simulator) and then communicates
5390 with that. The sub-program to run is specified using the syntax
5391 ``|<program> <args>'' vis:
5393 (gdb) set remotedebug 1
5394 (gdb) target extended-remote |mn10300-elf-sim program-args
5396 * MIPS 64 remote protocol
5398 A long standing bug in the mips64 remote protocol where by GDB
5399 expected certain 32 bit registers (ex SR) to be transfered as 32
5400 instead of 64 bits has been fixed.
5402 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5403 added to provide backward compatibility with older versions of GDB.
5405 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5407 The command ``set remotebinarydownload'' command has been replaced by
5408 ``set remote X-packet''. Other commands in ``set remote'' family
5409 include ``set remote P-packet''.
5411 * Breakpoint commands accept ranges.
5413 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5414 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5415 ``tracepoint passcount'' also accepts a range of tracepoints.
5417 * ``apropos'' command added.
5419 The ``apropos'' command searches through command names and
5420 documentation strings, printing out matches, making it much easier to
5421 try to find a command that does what you are looking for.
5425 A new machine oriented interface (MI) has been added to GDB. This
5426 interface is designed for debug environments running GDB as a separate
5427 process. This is part of the long term libGDB project. See the
5428 "GDB/MI" chapter of the GDB manual for further information. It can be
5429 enabled by configuring with:
5431 .../configure --enable-gdbmi
5433 *** Changes in GDB-4.18:
5435 * New native configurations
5437 HP-UX 10.20 hppa*-*-hpux10.20
5438 HP-UX 11.x hppa*-*-hpux11.0*
5439 M68K GNU/Linux m68*-*-linux*
5443 Fujitsu FR30 fr30-*-elf*
5444 Intel StrongARM strongarm-*-*
5445 Mitsubishi D30V d30v-*-*
5447 * OBSOLETE configurations
5449 Gould PowerNode, NP1 np1-*-*, pn-*-*
5451 Configurations that have been declared obsolete will be commented out,
5452 but the code will be left in place. If there is no activity to revive
5453 these configurations before the next release of GDB, the sources will
5454 be permanently REMOVED.
5458 As a compatibility experiment, GDB's source files buildsym.h and
5459 buildsym.c have been converted to pure standard C, no longer
5460 containing any K&R compatibility code. We believe that all systems in
5461 use today either come with a standard C compiler, or have a GCC port
5462 available. If this is not true, please report the affected
5463 configuration to bug-gdb@gnu.org immediately. See the README file for
5464 information about getting a standard C compiler if you don't have one
5469 GDB now uses readline 2.2.
5471 * set extension-language
5473 You can now control the mapping between filename extensions and source
5474 languages by using the `set extension-language' command. For instance,
5475 you can ask GDB to treat .c files as C++ by saying
5476 set extension-language .c c++
5477 The command `info extensions' lists all of the recognized extensions
5478 and their associated languages.
5480 * Setting processor type for PowerPC and RS/6000
5482 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5483 you can use the `set processor' command to specify what variant of the
5484 PowerPC family you are debugging. The command
5488 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5489 following PowerPC and RS6000 variants:
5491 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5492 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5494 403GC IBM PowerPC 403GC
5495 505 Motorola PowerPC 505
5496 860 Motorola PowerPC 860 or 850
5497 601 Motorola PowerPC 601
5498 602 Motorola PowerPC 602
5499 603 Motorola/IBM PowerPC 603 or 603e
5500 604 Motorola PowerPC 604 or 604e
5501 750 Motorola/IBM PowerPC 750 or 750
5503 At the moment, this command just tells GDB what to name the
5504 special-purpose processor registers. Since almost all the affected
5505 registers are inaccessible to user-level programs, this command is
5506 only useful for remote debugging in its present form.
5510 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5511 more extensive support for HP-UX. Added features include shared
5512 library support, kernel threads and hardware watchpoints for 11.00,
5513 support for HP's ANSI C and C++ compilers, and a compatibility mode
5514 for xdb and dbx commands.
5518 HP's donation includes the new concept of catchpoints, which is a
5519 generalization of the old catch command. On HP-UX, it is now possible
5520 to catch exec, fork, and vfork, as well as library loading.
5522 This means that the existing catch command has changed; its first
5523 argument now specifies the type of catch to be set up. See the
5524 output of "help catch" for a list of catchpoint types.
5526 * Debugging across forks
5528 On HP-UX, you can choose which process to debug when a fork() happens
5533 HP has donated a curses-based terminal user interface (TUI). To get
5534 it, build with --enable-tui. Although this can be enabled for any
5535 configuration, at present it only works for native HP debugging.
5537 * GDB remote protocol additions
5539 A new protocol packet 'X' that writes binary data is now available.
5540 Default behavior is to try 'X', then drop back to 'M' if the stub
5541 fails to respond. The settable variable `remotebinarydownload'
5542 allows explicit control over the use of 'X'.
5544 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5545 full 64-bit address. The command
5547 set remoteaddresssize 32
5549 can be used to revert to the old behaviour. For existing remote stubs
5550 the change should not be noticed, as the additional address information
5553 In order to assist in debugging stubs, you may use the maintenance
5554 command `packet' to send any text string to the stub. For instance,
5556 maint packet heythere
5558 sends the packet "$heythere#<checksum>". Note that it is very easy to
5559 disrupt a debugging session by sending the wrong packet at the wrong
5562 The compare-sections command allows you to compare section data on the
5563 target to what is in the executable file without uploading or
5564 downloading, by comparing CRC checksums.
5566 * Tracing can collect general expressions
5568 You may now collect general expressions at tracepoints. This requires
5569 further additions to the target-side stub; see tracepoint.c and
5570 doc/agentexpr.texi for further details.
5572 * mask-address variable for Mips
5574 For Mips targets, you may control the zeroing of the upper 32 bits of
5575 a 64-bit address by entering `set mask-address on'. This is mainly
5576 of interest to users of embedded R4xxx and R5xxx processors.
5578 * Higher serial baud rates
5580 GDB's serial code now allows you to specify baud rates 57600, 115200,
5581 230400, and 460800 baud. (Note that your host system may not be able
5582 to achieve all of these rates.)
5586 The i960 configuration now includes an initial implementation of a
5587 builtin simulator, contributed by Jim Wilson.
5590 *** Changes in GDB-4.17:
5592 * New native configurations
5594 Alpha GNU/Linux alpha*-*-linux*
5595 Unixware 2.x i[3456]86-unixware2*
5596 Irix 6.x mips*-sgi-irix6*
5597 PowerPC GNU/Linux powerpc-*-linux*
5598 PowerPC Solaris powerpcle-*-solaris*
5599 Sparc GNU/Linux sparc-*-linux*
5600 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5604 Argonaut Risc Chip (ARC) arc-*-*
5605 Hitachi H8/300S h8300*-*-*
5606 Matsushita MN10200 w/simulator mn10200-*-*
5607 Matsushita MN10300 w/simulator mn10300-*-*
5608 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5609 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5610 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5611 Mitsubishi D10V w/simulator d10v-*-*
5612 Mitsubishi M32R/D w/simulator m32r-*-elf*
5613 Tsqware Sparclet sparclet-*-*
5614 NEC V850 w/simulator v850-*-*
5616 * New debugging protocols
5618 ARM with RDI protocol arm*-*-*
5619 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5620 DDB and LSI variants of PMON protocol mips*-*-*
5621 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5622 PowerPC with SDS protocol powerpc{,le}-*-eabi
5623 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5627 All configurations can now understand and use the DWARF 2 debugging
5628 format. The choice is automatic, if the symbol file contains DWARF 2
5633 GDB now includes basic Java language support. This support is
5634 only useful with Java compilers that produce native machine code.
5636 * solib-absolute-prefix and solib-search-path
5638 For SunOS and SVR4 shared libraries, you may now set the prefix for
5639 loading absolute shared library symbol files, and the search path for
5640 locating non-absolute shared library symbol files.
5642 * Live range splitting
5644 GDB can now effectively debug code for which GCC has performed live
5645 range splitting as part of its optimization. See gdb/doc/LRS for
5646 more details on the expected format of the stabs information.
5650 GDB's support for the GNU Hurd, including thread debugging, has been
5651 updated to work with current versions of the Hurd.
5655 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5656 instruction set. ARM GDB automatically detects when Thumb
5657 instructions are in use, and adjusts disassembly and backtracing
5662 GDB's MIPS target configurations now handle the MIP16 16-bit
5667 GDB now includes support for overlays; if an executable has been
5668 linked such that multiple sections are based at the same address, GDB
5669 will decide which section to use for symbolic info. You can choose to
5670 control the decision manually, using overlay commands, or implement
5671 additional target-side support and use "overlay load-target" to bring
5672 in the overlay mapping. Do "help overlay" for more detail.
5676 The command "info symbol <address>" displays information about
5677 the symbol at the specified address.
5681 The standard remote protocol now includes an extension that allows
5682 asynchronous collection and display of trace data. This requires
5683 extensive support in the target-side debugging stub. Tracing mode
5684 includes a new interaction mode in GDB and new commands: see the
5685 file tracepoint.c for more details.
5689 Configurations for embedded MIPS now include a simulator contributed
5690 by Cygnus Solutions. The simulator supports the instruction sets
5691 of most MIPS variants.
5695 Sparc configurations may now include the ERC32 simulator contributed
5696 by the European Space Agency. The simulator is not built into
5697 Sparc targets by default; configure with --enable-sim to include it.
5701 For target configurations that may include multiple variants of a
5702 basic architecture (such as MIPS and SH), you may now set the
5703 architecture explicitly. "set arch" sets, "info arch" lists
5704 the possible architectures.
5706 *** Changes in GDB-4.16:
5708 * New native configurations
5710 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5711 M68K NetBSD m68k-*-netbsd*
5712 PowerPC AIX 4.x powerpc-*-aix*
5713 PowerPC MacOS powerpc-*-macos*
5714 PowerPC Windows NT powerpcle-*-cygwin32
5715 RS/6000 AIX 4.x rs6000-*-aix4*
5719 ARM with RDP protocol arm-*-*
5720 I960 with MON960 i960-*-coff
5721 MIPS VxWorks mips*-*-vxworks*
5722 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5723 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5725 Matra Sparclet sparclet-*-*
5729 The powerpc-eabi configuration now includes the PSIM simulator,
5730 contributed by Andrew Cagney, with assistance from Mike Meissner.
5731 PSIM is a very elaborate model of the PowerPC, including not only
5732 basic instruction set execution, but also details of execution unit
5733 performance and I/O hardware. See sim/ppc/README for more details.
5737 GDB now works with Solaris 2.5.
5739 * Windows 95/NT native
5741 GDB will now work as a native debugger on Windows 95 and Windows NT.
5742 To build it from source, you must use the "gnu-win32" environment,
5743 which uses a DLL to emulate enough of Unix to run the GNU tools.
5744 Further information, binaries, and sources are available at
5745 ftp.cygnus.com, under pub/gnu-win32.
5747 * dont-repeat command
5749 If a user-defined command includes the command `dont-repeat', then the
5750 command will not be repeated if the user just types return. This is
5751 useful if the command is time-consuming to run, so that accidental
5752 extra keystrokes don't run the same command many times.
5754 * Send break instead of ^C
5756 The standard remote protocol now includes an option to send a break
5757 rather than a ^C to the target in order to interrupt it. By default,
5758 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5760 * Remote protocol timeout
5762 The standard remote protocol includes a new variable `remotetimeout'
5763 that allows you to set the number of seconds before GDB gives up trying
5764 to read from the target. The default value is 2.
5766 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5768 By default GDB will automatically keep track of objects as they are
5769 loaded and unloaded by the dynamic linker. By using the command `set
5770 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5771 when shared library events occur, thus allowing you to set breakpoints
5772 in shared libraries which are explicitly loaded by the inferior.
5774 Note this feature does not work on hpux8. On hpux9 you must link
5775 /usr/lib/end.o into your program. This feature should work
5776 automatically on hpux10.
5778 * Irix 5.x hardware watchpoint support
5780 Irix 5 configurations now support the use of hardware watchpoints.
5782 * Mips protocol "SYN garbage limit"
5784 When debugging a Mips target using the `target mips' protocol, you
5785 may set the number of characters that GDB will ignore by setting
5786 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5787 every character. The default value is 1050.
5789 * Recording and replaying remote debug sessions
5791 If you set `remotelogfile' to the name of a file, gdb will write to it
5792 a recording of a remote debug session. This recording may then be
5793 replayed back to gdb using "gdbreplay". See gdbserver/README for
5794 details. This is useful when you have a problem with GDB while doing
5795 remote debugging; you can make a recording of the session and send it
5796 to someone else, who can then recreate the problem.
5798 * Speedups for remote debugging
5800 GDB includes speedups for downloading and stepping MIPS systems using
5801 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5802 and more efficient S-record downloading.
5804 * Memory use reductions and statistics collection
5806 GDB now uses less memory and reports statistics about memory usage.
5807 Try the `maint print statistics' command, for example.
5809 *** Changes in GDB-4.15:
5811 * Psymtabs for XCOFF
5813 The symbol reader for AIX GDB now uses partial symbol tables. This
5814 can greatly improve startup time, especially for large executables.
5816 * Remote targets use caching
5818 Remote targets now use a data cache to speed up communication with the
5819 remote side. The data cache could lead to incorrect results because
5820 it doesn't know about volatile variables, thus making it impossible to
5821 debug targets which use memory mapped I/O devices. `set remotecache
5822 off' turns the the data cache off.
5824 * Remote targets may have threads
5826 The standard remote protocol now includes support for multiple threads
5827 in the target system, using new protocol commands 'H' and 'T'. See
5828 gdb/remote.c for details.
5832 If GDB is configured with `--enable-netrom', then it will include
5833 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5834 acts as though it is a bank of ROM on the target board, but you can
5835 write into it over the network. GDB's support consists only of
5836 support for fast loading into the emulated ROM; to debug, you must use
5837 another protocol, such as standard remote protocol. The usual
5838 sequence is something like
5840 target nrom <netrom-hostname>
5842 target remote <netrom-hostname>:1235
5846 GDB now includes support for the Apple Macintosh, as a host only. It
5847 may be run as either an MPW tool or as a standalone application, and
5848 it can debug through the serial port. All the usual GDB commands are
5849 available, but to the target command, you must supply "serial" as the
5850 device type instead of "/dev/ttyXX". See mpw-README in the main
5851 directory for more information on how to build. The MPW configuration
5852 scripts */mpw-config.in support only a few targets, and only the
5853 mips-idt-ecoff target has been tested.
5857 GDB configuration now uses autoconf. This is not user-visible,
5858 but does simplify configuration and building.
5862 GDB now supports hpux10.
5864 *** Changes in GDB-4.14:
5866 * New native configurations
5868 x86 FreeBSD i[345]86-*-freebsd
5869 x86 NetBSD i[345]86-*-netbsd
5870 NS32k NetBSD ns32k-*-netbsd
5871 Sparc NetBSD sparc-*-netbsd
5875 A29K VxWorks a29k-*-vxworks
5876 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5877 CPU32 EST-300 emulator m68*-*-est*
5878 PowerPC ELF powerpc-*-elf
5881 * Alpha OSF/1 support for procfs
5883 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5884 possible to attach to running processes. As the mounting of the /proc
5885 filesystem is optional on the Alpha, GDB automatically determines
5886 the availability of /proc during startup. This can lead to problems
5887 if /proc is unmounted after GDB has been started.
5889 * Arguments to user-defined commands
5891 User commands may accept up to 10 arguments separated by whitespace.
5892 Arguments are accessed within the user command via $arg0..$arg9. A
5895 print $arg0 + $arg1 + $arg2
5897 To execute the command use:
5900 Defines the command "adder" which prints the sum of its three arguments.
5901 Note the arguments are text substitutions, so they may reference variables,
5902 use complex expressions, or even perform inferior function calls.
5904 * New `if' and `while' commands
5906 This makes it possible to write more sophisticated user-defined
5907 commands. Both commands take a single argument, which is the
5908 expression to evaluate, and must be followed by the commands to
5909 execute, one per line, if the expression is nonzero, the list being
5910 terminated by the word `end'. The `if' command list may include an
5911 `else' word, which causes the following commands to be executed only
5912 if the expression is zero.
5914 * Fortran source language mode
5916 GDB now includes partial support for Fortran 77. It will recognize
5917 Fortran programs and can evaluate a subset of Fortran expressions, but
5918 variables and functions may not be handled correctly. GDB will work
5919 with G77, but does not yet know much about symbols emitted by other
5922 * Better HPUX support
5924 Most debugging facilities now work on dynamic executables for HPPAs
5925 running hpux9 or later. You can attach to running dynamically linked
5926 processes, but by default the dynamic libraries will be read-only, so
5927 for instance you won't be able to put breakpoints in them. To change
5928 that behavior do the following before running the program:
5934 This will cause the libraries to be mapped private and read-write.
5935 To revert to the normal behavior, do this:
5941 You cannot set breakpoints or examine data in the library until after
5942 the library is loaded if the function/data symbols do not have
5945 GDB can now also read debug symbols produced by the HP C compiler on
5946 HPPAs (sorry, no C++, Fortran or 68k support).
5948 * Target byte order now dynamically selectable
5950 You can choose which byte order to use with a target system, via the
5951 commands "set endian big" and "set endian little", and you can see the
5952 current setting by using "show endian". You can also give the command
5953 "set endian auto", in which case GDB will use the byte order
5954 associated with the executable. Currently, only embedded MIPS
5955 configurations support dynamic selection of target byte order.
5957 * New DOS host serial code
5959 This version uses DPMI interrupts to handle buffered I/O, so you
5960 no longer need to run asynctsr when debugging boards connected to
5963 *** Changes in GDB-4.13:
5965 * New "complete" command
5967 This lists all the possible completions for the rest of the line, if it
5968 were to be given as a command itself. This is intended for use by emacs.
5970 * Trailing space optional in prompt
5972 "set prompt" no longer adds a space for you after the prompt you set. This
5973 allows you to set a prompt which ends in a space or one that does not.
5975 * Breakpoint hit counts
5977 "info break" now displays a count of the number of times the breakpoint
5978 has been hit. This is especially useful in conjunction with "ignore"; you
5979 can ignore a large number of breakpoint hits, look at the breakpoint info
5980 to see how many times the breakpoint was hit, then run again, ignoring one
5981 less than that number, and this will get you quickly to the last hit of
5984 * Ability to stop printing at NULL character
5986 "set print null-stop" will cause GDB to stop printing the characters of
5987 an array when the first NULL is encountered. This is useful when large
5988 arrays actually contain only short strings.
5990 * Shared library breakpoints
5992 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5993 breakpoints in shared libraries before the executable is run.
5995 * Hardware watchpoints
5997 There is a new hardware breakpoint for the watch command for sparclite
5998 targets. See gdb/sparclite/hw_breakpoint.note.
6000 Hardware watchpoints are also now supported under GNU/Linux.
6004 Annotations have been added. These are for use with graphical interfaces,
6005 and are still experimental. Currently only gdba.el uses these.
6007 * Improved Irix 5 support
6009 GDB now works properly with Irix 5.2.
6011 * Improved HPPA support
6013 GDB now works properly with the latest GCC and GAS.
6015 * New native configurations
6017 Sequent PTX4 i[34]86-sequent-ptx4
6018 HPPA running OSF/1 hppa*-*-osf*
6019 Atari TT running SVR4 m68*-*-sysv4*
6020 RS/6000 LynxOS rs6000-*-lynxos*
6024 OS/9000 i[34]86-*-os9k
6025 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6028 * Hitachi SH7000 and E7000-PC ICE support
6030 There is now support for communicating with the Hitachi E7000-PC ICE.
6031 This is available automatically when GDB is configured for the SH.
6035 As usual, a variety of small fixes and improvements, both generic
6036 and configuration-specific. See the ChangeLog for more detail.
6038 *** Changes in GDB-4.12:
6040 * Irix 5 is now supported
6044 GDB-4.12 on the HPPA has a number of changes which make it unable
6045 to debug the output from the currently released versions of GCC and
6046 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6047 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6048 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6051 *** Changes in GDB-4.11:
6053 * User visible changes:
6057 The "set remotedebug" option is now consistent between the mips remote
6058 target, remote targets using the gdb-specific protocol, UDI (AMD's
6059 debug protocol for the 29k) and the 88k bug monitor. It is now an
6060 integer specifying a debug level (normally 0 or 1, but 2 means more
6061 debugging info for the mips target).
6063 * DEC Alpha native support
6065 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6066 debug info, but GDB works fairly well with the DEC compiler and should
6067 work with a future GCC release. See the README file for a few
6068 Alpha-specific notes.
6070 * Preliminary thread implementation
6072 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6074 * LynxOS native and target support for 386
6076 This release has been hosted on LynxOS 2.2, and also can be configured
6077 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6080 * Improvements in C++ mangling/demangling.
6082 This release has much better g++ debugging, specifically in name
6083 mangling/demangling, virtual function calls, print virtual table,
6084 call methods, ...etc.
6086 *** Changes in GDB-4.10:
6088 * User visible changes:
6090 Remote debugging using the GDB-specific (`target remote') protocol now
6091 supports the `load' command. This is only useful if you have some
6092 other way of getting the stub to the target system, and you can put it
6093 somewhere in memory where it won't get clobbered by the download.
6095 Filename completion now works.
6097 When run under emacs mode, the "info line" command now causes the
6098 arrow to point to the line specified. Also, "info line" prints
6099 addresses in symbolic form (as well as hex).
6101 All vxworks based targets now support a user settable option, called
6102 vxworks-timeout. This option represents the number of seconds gdb
6103 should wait for responses to rpc's. You might want to use this if
6104 your vxworks target is, perhaps, a slow software simulator or happens
6105 to be on the far side of a thin network line.
6109 This release contains support for using a DEC alpha as a GDB host for
6110 cross debugging. Native alpha debugging is not supported yet.
6113 *** Changes in GDB-4.9:
6117 This is the first GDB release which is accompanied by a matching testsuite.
6118 The testsuite requires installation of dejagnu, which should be available
6119 via ftp from most sites that carry GNU software.
6123 'Cfront' style demangling has had its name changed to 'ARM' style, to
6124 emphasize that it was written from the specifications in the C++ Annotated
6125 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6126 disclaimers, it still generated too much confusion with users attempting to
6127 use gdb with AT&T cfront.
6131 GDB now uses a standard remote interface to a simulator library.
6132 So far, the library contains simulators for the Zilog Z8001/2, the
6133 Hitachi H8/300, H8/500 and Super-H.
6135 * New targets supported
6137 H8/300 simulator h8300-hitachi-hms or h8300hms
6138 H8/500 simulator h8500-hitachi-hms or h8500hms
6139 SH simulator sh-hitachi-hms or sh
6140 Z8000 simulator z8k-zilog-none or z8ksim
6141 IDT MIPS board over serial line mips-idt-ecoff
6143 Cross-debugging to GO32 targets is supported. It requires a custom
6144 version of the i386-stub.c module which is integrated with the
6145 GO32 memory extender.
6147 * New remote protocols
6149 MIPS remote debugging protocol.
6151 * New source languages supported
6153 This version includes preliminary support for Chill, a Pascal like language
6154 used by telecommunications companies. Chill support is also being integrated
6155 into the GNU compiler, but we don't know when it will be publically available.
6158 *** Changes in GDB-4.8:
6160 * HP Precision Architecture supported
6162 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6163 version of this support was available as a set of patches from the
6164 University of Utah. GDB does not support debugging of programs
6165 compiled with the HP compiler, because HP will not document their file
6166 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6167 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6169 Many problems in the preliminary version have been fixed.
6171 * Faster and better demangling
6173 We have improved template demangling and fixed numerous bugs in the GNU style
6174 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6175 character types (wchar_t) are now supported. Demangling of each symbol is now
6176 only done once, and is cached when the symbol table for a file is read in.
6177 This results in a small increase in memory usage for C programs, a moderate
6178 increase in memory usage for C++ programs, and a fantastic speedup in
6181 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6182 from the specifications in the Annotated Reference Manual, which AT&T's
6183 compiler does not actually implement.
6185 * G++ multiple inheritance compiler problem
6187 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6188 inheritance lattices was reworked to properly discover ambiguities. We
6189 recently found an example which causes this new algorithm to fail in a
6190 very subtle way, producing bad debug information for those classes.
6191 The file 'gcc.patch' (in this directory) can be applied to gcc to
6192 circumvent the problem. A future GCC release will contain a complete
6195 The previous G++ debug info problem (mentioned below for the gdb-4.7
6196 release) is fixed in gcc version 2.3.2.
6198 * Improved configure script
6200 The `configure' script will now attempt to guess your system type if
6201 you don't supply a host system type. The old scheme of supplying a
6202 host system triplet is preferable over using this. All the magic is
6203 done in the new `config.guess' script. Examine it for details.
6205 We have also brought our configure script much more in line with the FSF's
6206 version. It now supports the --with-xxx options. In particular,
6207 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6208 The resulting GDB will not be able to read arbitrary object file formats --
6209 only the format ``expected'' to be used on the configured target system.
6210 We hope to make this the default in a future release.
6212 * Documentation improvements
6214 There's new internal documentation on how to modify GDB, and how to
6215 produce clean changes to the code. We implore people to read it
6216 before submitting changes.
6218 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6219 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6220 `info' files are also provided. To build `info' files from scratch,
6221 you will need the latest `makeinfo' release, which will be available in
6222 a future texinfo-X.Y release.
6224 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6225 We're not sure exactly which versions have this problem, but it has
6226 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6227 or better. If that isn't possible, there is a patch in
6228 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6229 around this problem.
6233 GDB now supports array constants that can be used in expressions typed in by
6234 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6235 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6238 The new directory `gdb/sparclite' contains a program that demonstrates
6239 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6241 * New native hosts supported
6243 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6244 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6246 * New targets supported
6248 AMD 29k family via UDI a29k-amd-udi or udi29k
6250 * New file formats supported
6252 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6253 HPUX core files, and SCO 3.2v2 core files.
6257 Attaching to processes now works again; thanks for the many bug reports.
6259 We have also stomped on a bunch of core dumps caused by
6260 printf_filtered("%s") problems.
6262 We eliminated a copyright problem on the rpc and ptrace header files
6263 for VxWorks, which was discovered at the last minute during the 4.7
6264 release. You should now be able to build a VxWorks GDB.
6266 You can now interrupt gdb while an attached process is running. This
6267 will cause the attached process to stop, and give control back to GDB.
6269 We fixed problems caused by using too many file descriptors
6270 for reading symbols from object files and libraries. This was
6271 especially a problem for programs that used many (~100) shared
6274 The `step' command now only enters a subroutine if there is line number
6275 information for the subroutine. Otherwise it acts like the `next'
6276 command. Previously, `step' would enter subroutines if there was
6277 any debugging information about the routine. This avoids problems
6278 when using `cc -g1' on MIPS machines.
6280 * Internal improvements
6282 GDB's internal interfaces have been improved to make it easier to support
6283 debugging of multiple languages in the future.
6285 GDB now uses a common structure for symbol information internally.
6286 Minimal symbols (derived from linkage symbols in object files), partial
6287 symbols (from a quick scan of debug information), and full symbols
6288 contain a common subset of information, making it easier to write
6289 shared code that handles any of them.
6291 * New command line options
6293 We now accept --silent as an alias for --quiet.
6297 The memory-mapped-malloc library is now licensed under the GNU Library
6298 General Public License.
6300 *** Changes in GDB-4.7:
6302 * Host/native/target split
6304 GDB has had some major internal surgery to untangle the support for
6305 hosts and remote targets. Now, when you configure GDB for a remote
6306 target, it will no longer load in all of the support for debugging
6307 local programs on the host. When fully completed and tested, this will
6308 ensure that arbitrary host/target combinations are possible.
6310 The primary conceptual shift is to separate the non-portable code in
6311 GDB into three categories. Host specific code is required any time GDB
6312 is compiled on that host, regardless of the target. Target specific
6313 code relates to the peculiarities of the target, but can be compiled on
6314 any host. Native specific code is everything else: it can only be
6315 built when the host and target are the same system. Child process
6316 handling and core file support are two common `native' examples.
6318 GDB's use of /proc for controlling Unix child processes is now cleaner.
6319 It has been split out into a single module under the `target_ops' vector,
6320 plus two native-dependent functions for each system that uses /proc.
6322 * New hosts supported
6324 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6325 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6326 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6328 * New targets supported
6330 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6331 68030 and CPU32 m68030-*-*, m68332-*-*
6333 * New native hosts supported
6335 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6336 (386bsd is not well tested yet)
6337 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6339 * New file formats supported
6341 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6342 supports reading of `a.out.adobe' object files, which are an a.out
6343 format extended with minimal information about multiple sections.
6347 `show copying' is the same as the old `info copying'.
6348 `show warranty' is the same as `info warrantee'.
6349 These were renamed for consistency. The old commands continue to work.
6351 `info handle' is a new alias for `info signals'.
6353 You can now define pre-command hooks, which attach arbitrary command
6354 scripts to any command. The commands in the hook will be executed
6355 prior to the user's command. You can also create a hook which will be
6356 executed whenever the program stops. See gdb.texinfo.
6360 We now deal with Cfront style name mangling, and can even extract type
6361 info from mangled symbols. GDB can automatically figure out which
6362 symbol mangling style your C++ compiler uses.
6364 Calling of methods and virtual functions has been improved as well.
6368 The crash that occured when debugging Sun Ansi-C compiled binaries is
6369 fixed. This was due to mishandling of the extra N_SO stabs output
6372 We also finally got Ultrix 4.2 running in house, and fixed core file
6373 support, with help from a dozen people on the net.
6375 John M. Farrell discovered that the reason that single-stepping was so
6376 slow on all of the Mips based platforms (primarily SGI and DEC) was
6377 that we were trying to demangle and lookup a symbol used for internal
6378 purposes on every instruction that was being stepped through. Changing
6379 the name of that symbol so that it couldn't be mistaken for a C++
6380 mangled symbol sped things up a great deal.
6382 Rich Pixley sped up symbol lookups in general by getting much smarter
6383 about when C++ symbol mangling is necessary. This should make symbol
6384 completion (TAB on the command line) much faster. It's not as fast as
6385 we'd like, but it's significantly faster than gdb-4.6.
6389 A new user controllable variable 'call_scratch_address' can
6390 specify the location of a scratch area to be used when GDB
6391 calls a function in the target. This is necessary because the
6392 usual method of putting the scratch area on the stack does not work
6393 in systems that have separate instruction and data spaces.
6395 We integrated changes to support the 29k UDI (Universal Debugger
6396 Interface), but discovered at the last minute that we didn't have all
6397 of the appropriate copyright paperwork. We are working with AMD to
6398 resolve this, and hope to have it available soon.
6402 We have sped up the remote serial line protocol, especially for targets
6403 with lots of registers. It now supports a new `expedited status' ('T')
6404 message which can be used in place of the existing 'S' status message.
6405 This allows the remote stub to send only the registers that GDB
6406 needs to make a quick decision about single-stepping or conditional
6407 breakpoints, eliminating the need to fetch the entire register set for
6408 each instruction being stepped through.
6410 The GDB remote serial protocol now implements a write-through cache for
6411 registers, only re-reading the registers if the target has run.
6413 There is also a new remote serial stub for SPARC processors. You can
6414 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6415 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6416 processor with a serial port.
6420 Configure.in files have become much easier to read and modify. A new
6421 `table driven' format makes it more obvious what configurations are
6422 supported, and what files each one uses.
6426 There is a new opcodes library which will eventually contain all of the
6427 disassembly routines and opcode tables. At present, it only contains
6428 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6429 disassembler (binutils/objdump) to share these routines.
6431 The libiberty library is now copylefted under the GNU Library General
6432 Public License. This allows more liberal use, and was done so libg++
6433 can use it. This makes no difference to GDB, since the Library License
6434 grants all the rights from the General Public License.
6438 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6439 reference to the stabs symbol info used by the debugger. It is (as far
6440 as we know) the only published document on this fascinating topic. We
6441 encourage you to read it, compare it to the stabs information on your
6442 system, and send improvements on the document in general (to
6443 bug-gdb@prep.ai.mit.edu).
6445 And, of course, many bugs have been fixed.
6448 *** Changes in GDB-4.6:
6450 * Better support for C++ function names
6452 GDB now accepts as input the "demangled form" of C++ overloaded function
6453 names and member function names, and can do command completion on such names
6454 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6455 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6456 Make use of command completion, it is your friend.
6458 GDB also now accepts a variety of C++ mangled symbol formats. They are
6459 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6460 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6461 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6462 for the list of formats.
6464 * G++ symbol mangling problem
6466 Recent versions of gcc have a bug in how they emit debugging information for
6467 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6468 directory) can be applied to gcc to fix the problem. Alternatively, if you
6469 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6470 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6471 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6474 * New 'maintenance' command
6476 All of the commands related to hacking GDB internals have been moved out of
6477 the main command set, and now live behind the 'maintenance' command. This
6478 can also be abbreviated as 'mt'. The following changes were made:
6480 dump-me -> maintenance dump-me
6481 info all-breakpoints -> maintenance info breakpoints
6482 printmsyms -> maintenance print msyms
6483 printobjfiles -> maintenance print objfiles
6484 printpsyms -> maintenance print psymbols
6485 printsyms -> maintenance print symbols
6487 The following commands are new:
6489 maintenance demangle Call internal GDB demangler routine to
6490 demangle a C++ link name and prints the result.
6491 maintenance print type Print a type chain for a given symbol
6493 * Change to .gdbinit file processing
6495 We now read the $HOME/.gdbinit file before processing the argv arguments
6496 (e.g. reading symbol files or core files). This allows global parameters to
6497 be set, which will apply during the symbol reading. The ./.gdbinit is still
6498 read after argv processing.
6500 * New hosts supported
6502 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6504 GNU/Linux support i386-unknown-linux or linux
6506 We are also including code to support the HP/PA running BSD and HPUX. This
6507 is almost guaranteed not to work, as we didn't have time to test or build it
6508 for this release. We are including it so that the more adventurous (or
6509 masochistic) of you can play with it. We also had major problems with the
6510 fact that the compiler that we got from HP doesn't support the -g option.
6513 * New targets supported
6515 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6517 * More smarts about finding #include files
6519 GDB now remembers the compilation directory for all include files, and for
6520 all files from which C is generated (like yacc and lex sources). This
6521 greatly improves GDB's ability to find yacc/lex sources, and include files,
6522 especially if you are debugging your program from a directory different from
6523 the one that contains your sources.
6525 We also fixed a bug which caused difficulty with listing and setting
6526 breakpoints in include files which contain C code. (In the past, you had to
6527 try twice in order to list an include file that you hadn't looked at before.)
6529 * Interesting infernals change
6531 GDB now deals with arbitrary numbers of sections, where the symbols for each
6532 section must be relocated relative to that section's landing place in the
6533 target's address space. This work was needed to support ELF with embedded
6534 stabs used by Solaris-2.0.
6536 * Bug fixes (of course!)
6538 There have been loads of fixes for the following things:
6539 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6540 i960, stabs, DOS(GO32), procfs, etc...
6542 See the ChangeLog for details.
6544 *** Changes in GDB-4.5:
6546 * New machines supported (host and target)
6548 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6550 SGI Irix-4.x mips-sgi-irix4 or iris4
6552 * New malloc package
6554 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6555 Mmalloc is capable of handling mutiple heaps of memory. It is also
6556 capable of saving a heap to a file, and then mapping it back in later.
6557 This can be used to greatly speedup the startup of GDB by using a
6558 pre-parsed symbol table which lives in a mmalloc managed heap. For
6559 more details, please read mmalloc/mmalloc.texi.
6563 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6564 'help info proc' for details.
6566 * MIPS ecoff symbol table format
6568 The code that reads MIPS symbol table format is now supported on all hosts.
6569 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6572 * File name changes for MS-DOS
6574 Many files in the config directories have been renamed to make it easier to
6575 support GDB on MS-DOSe systems (which have very restrictive file name
6576 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6577 environment) is close to working but has some remaining problems. Note
6578 that debugging of DOS programs is not supported, due to limitations
6579 in the ``operating system'', but it can be used to host cross-debugging.
6581 * Cross byte order fixes
6583 Many fixes have been made to support cross debugging of Sparc and MIPS
6584 targets from hosts whose byte order differs.
6586 * New -mapped and -readnow options
6588 If memory-mapped files are available on your system through the 'mmap'
6589 system call, you can use the -mapped option on the `file' or
6590 `symbol-file' commands to cause GDB to write the symbols from your
6591 program into a reusable file. If the program you are debugging is
6592 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6593 Future GDB debugging sessions will notice the presence of this file,
6594 and will quickly map in symbol information from it, rather than reading
6595 the symbol table from the executable program. Using the '-mapped'
6596 option in a GDB `file' or `symbol-file' command has the same effect as
6597 starting GDB with the '-mapped' command-line option.
6599 You can cause GDB to read the entire symbol table immediately by using
6600 the '-readnow' option with any of the commands that load symbol table
6601 information (or on the GDB command line). This makes the command
6602 slower, but makes future operations faster.
6604 The -mapped and -readnow options are typically combined in order to
6605 build a `fred.syms' file that contains complete symbol information.
6606 A simple GDB invocation to do nothing but build a `.syms' file for future
6609 gdb -batch -nx -mapped -readnow programname
6611 The `.syms' file is specific to the host machine on which GDB is run.
6612 It holds an exact image of GDB's internal symbol table. It cannot be
6613 shared across multiple host platforms.
6615 * longjmp() handling
6617 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6618 siglongjmp() without losing control. This feature has not yet been ported to
6619 all systems. It currently works on many 386 platforms, all MIPS-based
6620 platforms (SGI, DECstation, etc), and Sun3/4.
6624 Preliminary work has been put in to support the new Solaris OS from Sun. At
6625 this time, it can control and debug processes, but it is not capable of
6630 As always, many many bug fixes. The major areas were with g++, and mipsread.
6631 People using the MIPS-based platforms should experience fewer mysterious
6632 crashes and trashed symbol tables.
6634 *** Changes in GDB-4.4:
6636 * New machines supported (host and target)
6638 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6640 BSD Reno on Vax vax-dec-bsd
6641 Ultrix on Vax vax-dec-ultrix
6643 * New machines supported (target)
6645 AMD 29000 embedded, using EBMON a29k-none-none
6649 GDB continues to improve its handling of C++. `References' work better.
6650 The demangler has also been improved, and now deals with symbols mangled as
6651 per the Annotated C++ Reference Guide.
6653 GDB also now handles `stabs' symbol information embedded in MIPS
6654 `ecoff' symbol tables. Since the ecoff format was not easily
6655 extensible to handle new languages such as C++, this appeared to be a
6656 good way to put C++ debugging info into MIPS binaries. This option
6657 will be supported in the GNU C compiler, version 2, when it is
6660 * New features for SVR4
6662 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6663 shared libraries. Debugging dynamically linked programs should present
6664 only minor differences from debugging statically linked programs.
6666 The `info proc' command will print out information about any process
6667 on an SVR4 system (including the one you are debugging). At the moment,
6668 it prints the address mappings of the process.
6670 If you bring up GDB on another SVR4 system, please send mail to
6671 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6673 * Better dynamic linking support in SunOS
6675 Reading symbols from shared libraries which contain debugging symbols
6676 now works properly. However, there remain issues such as automatic
6677 skipping of `transfer vector' code during function calls, which
6678 make it harder to debug code in a shared library, than to debug the
6679 same code linked statically.
6683 GDB is now using the latest `getopt' routines from the FSF. This
6684 version accepts the -- prefix for options with long names. GDB will
6685 continue to accept the old forms (-option and +option) as well.
6686 Various single letter abbreviations for options have been explicity
6687 added to the option table so that they won't get overshadowed in the
6688 future by other options that begin with the same letter.
6692 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6693 Many assorted bugs have been handled. Many more remain to be handled.
6694 See the various ChangeLog files (primarily in gdb and bfd) for details.
6697 *** Changes in GDB-4.3:
6699 * New machines supported (host and target)
6701 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6702 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6703 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6705 * Almost SCO Unix support
6707 We had hoped to support:
6708 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6709 (except for core file support), but we discovered very late in the release
6710 that it has problems with process groups that render gdb unusable. Sorry
6711 about that. I encourage people to fix it and post the fixes.
6713 * Preliminary ELF and DWARF support
6715 GDB can read ELF object files on System V Release 4, and can handle
6716 debugging records for C, in DWARF format, in ELF files. This support
6717 is preliminary. If you bring up GDB on another SVR4 system, please
6718 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6723 GDB now uses the latest `readline' library. One user-visible change
6724 is that two tabs will list possible command completions, which previously
6725 required typing M-? (meta-question mark, or ESC ?).
6729 The `stepi' bug that many of you noticed has been squashed.
6730 Many bugs in C++ have been handled. Many more remain to be handled.
6731 See the various ChangeLog files (primarily in gdb and bfd) for details.
6733 * State of the MIPS world (in case you wondered):
6735 GDB can understand the symbol tables emitted by the compilers
6736 supplied by most vendors of MIPS-based machines, including DEC. These
6737 symbol tables are in a format that essentially nobody else uses.
6739 Some versions of gcc come with an assembler post-processor called
6740 mips-tfile. This program is required if you want to do source-level
6741 debugging of gcc-compiled programs. I believe FSF does not ship
6742 mips-tfile with gcc version 1, but it will eventually come with gcc
6745 Debugging of g++ output remains a problem. g++ version 1.xx does not
6746 really support it at all. (If you're lucky, you should be able to get
6747 line numbers and stack traces to work, but no parameters or local
6748 variables.) With some work it should be possible to improve the
6751 When gcc version 2 is released, you will have somewhat better luck.
6752 However, even then you will get confusing results for inheritance and
6755 We will eventually provide full debugging of g++ output on
6756 DECstations. This will probably involve some kind of stabs-in-ecoff
6757 encapulation, but the details have not been worked out yet.
6760 *** Changes in GDB-4.2:
6762 * Improved configuration
6764 Only one copy of `configure' exists now, and it is not self-modifying.
6765 Porting BFD is simpler.
6769 The `step' and `next' commands now only stop at the first instruction
6770 of a source line. This prevents the multiple stops that used to occur
6771 in switch statements, for-loops, etc. `Step' continues to stop if a
6772 function that has debugging information is called within the line.
6776 Lots of small bugs fixed. More remain.
6778 * New host supported (not target)
6780 Intel 386 PC clone running Mach i386-none-mach
6783 *** Changes in GDB-4.1:
6785 * Multiple source language support
6787 GDB now has internal scaffolding to handle several source languages.
6788 It determines the type of each source file from its filename extension,
6789 and will switch expression parsing and number formatting to match the
6790 language of the function in the currently selected stack frame.
6791 You can also specifically set the language to be used, with
6792 `set language c' or `set language modula-2'.
6796 GDB now has preliminary support for the GNU Modula-2 compiler,
6797 currently under development at the State University of New York at
6798 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6799 continue through the fall of 1991 and into 1992.
6801 Other Modula-2 compilers are currently not supported, and attempting to
6802 debug programs compiled with them will likely result in an error as the
6803 symbol table is read. Feel free to work on it, though!
6805 There are hooks in GDB for strict type checking and range checking,
6806 in the `Modula-2 philosophy', but they do not currently work.
6810 GDB can now write to executable and core files (e.g. patch
6811 a variable's value). You must turn this switch on, specify
6812 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6813 by assigning a new value to a variable. Modifications take
6816 * Automatic SunOS shared library reading
6818 When you run your program, GDB automatically determines where its
6819 shared libraries (if any) have been loaded, and reads their symbols.
6820 The `share' command is no longer needed. This also works when
6821 examining core files.
6825 You can specify the number of lines that the `list' command shows.
6828 * New machines supported (host and target)
6830 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6831 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6832 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6834 * New hosts supported (not targets)
6836 IBM RT/PC: romp-ibm-aix or rtpc
6838 * New targets supported (not hosts)
6840 AMD 29000 embedded with COFF a29k-none-coff
6841 AMD 29000 embedded with a.out a29k-none-aout
6842 Ultracomputer remote kernel debug a29k-nyu-kern
6844 * New remote interfaces
6850 *** Changes in GDB-4.0:
6854 Wide output is wrapped at good places to make the output more readable.
6856 Gdb now supports cross-debugging from a host machine of one type to a
6857 target machine of another type. Communication with the target system
6858 is over serial lines. The ``target'' command handles connecting to the
6859 remote system; the ``load'' command will download a program into the
6860 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6861 also supports debugging of realtime processes running under VxWorks,
6862 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6863 stub on the target system.
6865 New CPUs supported include the AMD 29000 and Intel 960.
6867 GDB now reads object files and symbol tables via a ``binary file''
6868 library, which allows a single copy of GDB to debug programs of multiple
6869 object file types such as a.out and coff.
6871 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6872 refcard.dvi and refcard.ps are available to format it).
6875 * Control-Variable user interface simplified
6877 All variables that control the operation of the debugger can be set
6878 by the ``set'' command, and displayed by the ``show'' command.
6880 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6881 ``Show prompt'' produces the response:
6882 Gdb's prompt is new-gdb=>.
6884 What follows are the NEW set commands. The command ``help set'' will
6885 print a complete list of old and new set commands. ``help set FOO''
6886 will give a longer description of the variable FOO. ``show'' will show
6887 all of the variable descriptions and their current settings.
6889 confirm on/off: Enables warning questions for operations that are
6890 hard to recover from, e.g. rerunning the program while
6891 it is already running. Default is ON.
6893 editing on/off: Enables EMACS style command line editing
6894 of input. Previous lines can be recalled with
6895 control-P, the current line can be edited with control-B,
6896 you can search for commands with control-R, etc.
6899 history filename NAME: NAME is where the gdb command history
6900 will be stored. The default is .gdb_history,
6901 or the value of the environment variable
6904 history size N: The size, in commands, of the command history. The
6905 default is 256, or the value of the environment variable
6908 history save on/off: If this value is set to ON, the history file will
6909 be saved after exiting gdb. If set to OFF, the
6910 file will not be saved. The default is OFF.
6912 history expansion on/off: If this value is set to ON, then csh-like
6913 history expansion will be performed on
6914 command line input. The default is OFF.
6916 radix N: Sets the default radix for input and output. It can be set
6917 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6918 in the current radix, so "set radix 10" is always a no-op.
6920 height N: This integer value is the number of lines on a page. Default
6921 is 24, the current `stty rows'' setting, or the ``li#''
6922 setting from the termcap entry matching the environment
6925 width N: This integer value is the number of characters on a line.
6926 Default is 80, the current `stty cols'' setting, or the ``co#''
6927 setting from the termcap entry matching the environment
6930 Note: ``set screensize'' is obsolete. Use ``set height'' and
6931 ``set width'' instead.
6933 print address on/off: Print memory addresses in various command displays,
6934 such as stack traces and structure values. Gdb looks
6935 more ``symbolic'' if you turn this off; it looks more
6936 ``machine level'' with it on. Default is ON.
6938 print array on/off: Prettyprint arrays. New convenient format! Default
6941 print demangle on/off: Print C++ symbols in "source" form if on,
6944 print asm-demangle on/off: Same, for assembler level printouts
6947 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6950 * Support for Epoch Environment.
6952 The epoch environment is a version of Emacs v18 with windowing. One
6953 new command, ``inspect'', is identical to ``print'', except that if you
6954 are running in the epoch environment, the value is printed in its own
6958 * Support for Shared Libraries
6960 GDB can now debug programs and core files that use SunOS shared libraries.
6961 Symbols from a shared library cannot be referenced
6962 before the shared library has been linked with the program (this
6963 happens after you type ``run'' and before the function main() is entered).
6964 At any time after this linking (including when examining core files
6965 from dynamically linked programs), gdb reads the symbols from each
6966 shared library when you type the ``sharedlibrary'' command.
6967 It can be abbreviated ``share''.
6969 sharedlibrary REGEXP: Load shared object library symbols for files
6970 matching a unix regular expression. No argument
6971 indicates to load symbols for all shared libraries.
6973 info sharedlibrary: Status of loaded shared libraries.
6978 A watchpoint stops execution of a program whenever the value of an
6979 expression changes. Checking for this slows down execution
6980 tremendously whenever you are in the scope of the expression, but is
6981 quite useful for catching tough ``bit-spreader'' or pointer misuse
6982 problems. Some machines such as the 386 have hardware for doing this
6983 more quickly, and future versions of gdb will use this hardware.
6985 watch EXP: Set a watchpoint (breakpoint) for an expression.
6987 info watchpoints: Information about your watchpoints.
6989 delete N: Deletes watchpoint number N (same as breakpoints).
6990 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6991 enable N: Re-enables watchpoint number N (same as breakpoints).
6994 * C++ multiple inheritance
6996 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6999 * C++ exception handling
7001 Gdb now supports limited C++ exception handling. Besides the existing
7002 ability to breakpoint on an exception handler, gdb can breakpoint on
7003 the raising of an exception (before the stack is peeled back to the
7006 catch FOO: If there is a FOO exception handler in the dynamic scope,
7007 set a breakpoint to catch exceptions which may be raised there.
7008 Multiple exceptions (``catch foo bar baz'') may be caught.
7010 info catch: Lists all exceptions which may be caught in the
7011 current stack frame.
7014 * Minor command changes
7016 The command ``call func (arg, arg, ...)'' now acts like the print
7017 command, except it does not print or save a value if the function's result
7018 is void. This is similar to dbx usage.
7020 The ``up'' and ``down'' commands now always print the frame they end up
7021 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7022 frames without printing.
7024 * New directory command
7026 'dir' now adds directories to the FRONT of the source search path.
7027 The path starts off empty. Source files that contain debug information
7028 about the directory in which they were compiled can be found even
7029 with an empty path; Sun CC and GCC include this information. If GDB can't
7030 find your source file in the current directory, type "dir .".
7032 * Configuring GDB for compilation
7034 For normal use, type ``./configure host''. See README or gdb.texinfo
7037 GDB now handles cross debugging. If you are remotely debugging between
7038 two different machines, type ``./configure host -target=targ''.
7039 Host is the machine where GDB will run; targ is the machine
7040 where the program that you are debugging will run.