1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
8 * The 'set disassembler-options' command now supports specifying options
11 * The 'symbol-file' command now accepts an '-o' option to add a relative
12 offset to all sections.
14 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
15 a relative offset to all sections, but it allows to override the load
16 address of individual sections using '-s'.
18 * The 'add-symbol-file' command no longer requires the second argument
19 (address of the text section).
21 * The endianness used with the 'set endian auto' mode in the absence of
22 an executable selected for debugging is now the last endianness chosen
23 either by one of the 'set endian big' and 'set endian little' commands
24 or by inferring from the last executable used, rather than the startup
27 * The pager now allows a "c" response, meaning to disable the pager
28 for the rest of the current command.
30 * The commands 'info variables/functions/types' now show the source line
31 numbers of symbol definitions when available.
33 * 'info proc' now works on running processes on FreeBSD systems and core
34 files created on FreeBSD systems.
36 * C expressions can now use _Alignof, and C++ expressions can now use
43 Control display of debugging info regarding the FreeBSD native target.
45 set|show varsize-limit
46 This new setting allows the user to control the maximum size of Ada
47 objects being printed when those objects have a variable type,
48 instead of that maximum size being hardcoded to 65536 bytes.
50 set|show record btrace cpu
51 Controls the processor to be used for enabling errata workarounds for
54 maint check libthread-db
55 Run integrity checks on the current inferior's thread debugging
58 maint set check-libthread-db (on|off)
59 maint show check-libthread-db
60 Control whether to run integrity checks on inferior specific thread
61 debugging libraries as they are loaded. The default is not to
66 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
68 ** The commands attached to a breakpoint can be set by assigning to
69 the breakpoint's "commands" field.
71 ** gdb.execute can now execute multi-line gdb commands.
73 ** The new functions gdb.convenience_variable and
74 gdb.set_convenience_variable can be used to get and set the value
75 of convenience variables.
77 ** A gdb.Parameter will no longer print the "set" help text on an
78 ordinary "set"; instead by default a "set" will be silent unless
79 the get_set_string method returns a non-empty string.
83 RiscV ELF riscv*-*-elf
85 * Removed targets and native configurations
87 m88k running OpenBSD m88*-*-openbsd*
88 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
89 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
90 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
92 * Aarch64/Linux hardware watchpoints improvements
94 Hardware watchpoints on unaligned addresses are now properly
95 supported when running Linux kernel 4.10 or higher: read and access
96 watchpoints are no longer spuriously missed, and all watchpoints
97 lengths between 1 and 8 bytes are supported. On older kernels,
98 watchpoints set on unaligned addresses are no longer missed, with
99 the tradeoff that there is a possibility of false hits being
102 * New configure options
104 --enable-codesign=CERT
105 This can be used to invoke "codesign -s CERT" after building gdb.
106 This option is useful on macOS, where code signing is required for
107 gdb to work properly.
109 *** Changes in GDB 8.1
111 * GDB now supports dynamically creating arbitrary register groups specified
112 in XML target descriptions. This allows for finer grain grouping of
113 registers on systems with a large amount of registers.
115 * The 'ptype' command now accepts a '/o' flag, which prints the
116 offsets and sizes of fields in a struct, like the pahole(1) tool.
118 * New "--readnever" command line option instructs GDB to not read each
119 symbol file's symbolic debug information. This makes startup faster
120 but at the expense of not being able to perform symbolic debugging.
121 This option is intended for use cases where symbolic debugging will
122 not be used, e.g., when you only need to dump the debuggee's core.
124 * GDB now uses the GNU MPFR library, if available, to emulate target
125 floating-point arithmetic during expression evaluation when the target
126 uses different floating-point formats than the host. At least version
127 3.1 of GNU MPFR is required.
129 * GDB now supports access to the guarded-storage-control registers and the
130 software-based guarded-storage broadcast control registers on IBM z14.
132 * On Unix systems, GDB now supports transmitting environment variables
133 that are to be set or unset to GDBserver. These variables will
134 affect the environment to be passed to the remote inferior.
136 To inform GDB of environment variables that are to be transmitted to
137 GDBserver, use the "set environment" command. Only user set
138 environment variables are sent to GDBserver.
140 To inform GDB of environment variables that are to be unset before
141 the remote inferior is started by the GDBserver, use the "unset
142 environment" command.
144 * Completion improvements
146 ** GDB can now complete function parameters in linespecs and
147 explicit locations without quoting. When setting breakpoints,
148 quoting around functions names to help with TAB-completion is
149 generally no longer necessary. For example, this now completes
152 (gdb) b function(in[TAB]
153 (gdb) b function(int)
155 Related, GDB is no longer confused with completing functions in
156 C++ anonymous namespaces:
159 (gdb) b (anonymous namespace)::[TAB][TAB]
160 (anonymous namespace)::a_function()
161 (anonymous namespace)::b_function()
163 ** GDB now has much improved linespec and explicit locations TAB
164 completion support, that better understands what you're
165 completing and offers better suggestions. For example, GDB no
166 longer offers data symbols as possible completions when you're
167 setting a breakpoint.
169 ** GDB now TAB-completes label symbol names.
171 ** The "complete" command now mimics TAB completion accurately.
173 * New command line options (gcore)
176 Dump all memory mappings.
178 * Breakpoints on C++ functions are now set on all scopes by default
180 By default, breakpoints on functions/methods are now interpreted as
181 specifying all functions with the given name ignoring missing
182 leading scopes (namespaces and classes).
184 For example, assuming a C++ program with symbols named:
189 both commands "break func()" and "break B::func()" set a breakpoint
192 You can use the new flag "-qualified" to override this. This makes
193 GDB interpret the specified function name as a complete
194 fully-qualified name instead. For example, using the same C++
195 program, the "break -q B::func" command sets a breakpoint on
196 "B::func", only. A parameter has been added to the Python
197 gdb.Breakpoint constructor to achieve the same result when creating
198 a breakpoint from Python.
200 * Breakpoints on functions marked with C++ ABI tags
202 GDB can now set breakpoints on functions marked with C++ ABI tags
203 (e.g., [abi:cxx11]). See here for a description of ABI tags:
204 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
206 Functions with a C++11 abi tag are demangled/displayed like this:
208 function[abi:cxx11](int)
211 You can now set a breakpoint on such functions simply as if they had
214 (gdb) b function(int)
216 Or if you need to disambiguate between tags, like:
218 (gdb) b function[abi:other_tag](int)
220 Tab completion was adjusted accordingly as well.
224 ** New events gdb.new_inferior, gdb.inferior_deleted, and
225 gdb.new_thread are emitted. See the manual for further
226 description of these.
228 ** A new function, "gdb.rbreak" has been added to the Python API.
229 This function allows the setting of a large number of breakpoints
230 via a regex pattern in Python. See the manual for further details.
232 ** Python breakpoints can now accept explicit locations. See the
233 manual for a further description of this feature.
236 * New features in the GDB remote stub, GDBserver
238 ** GDBserver is now able to start inferior processes with a
239 specified initial working directory.
241 The user can set the desired working directory to be used from
242 GDB using the new "set cwd" command.
244 ** New "--selftest" command line option runs some GDBserver self
245 tests. These self tests are disabled in releases.
247 ** On Unix systems, GDBserver now does globbing expansion and variable
248 substitution in inferior command line arguments.
250 This is done by starting inferiors using a shell, like GDB does.
251 See "set startup-with-shell" in the user manual for how to disable
252 this from GDB when using "target extended-remote". When using
253 "target remote", you can disable the startup with shell by using the
254 new "--no-startup-with-shell" GDBserver command line option.
256 ** On Unix systems, GDBserver now supports receiving environment
257 variables that are to be set or unset from GDB. These variables
258 will affect the environment to be passed to the inferior.
260 * When catching an Ada exception raised with a message, GDB now prints
261 the message in the catchpoint hit notification. In GDB/MI mode, that
262 information is provided as an extra field named "exception-message"
263 in the *stopped notification.
265 * Trait objects can now be inspected When debugging Rust code. This
266 requires compiler support which will appear in Rust 1.24.
270 QEnvironmentHexEncoded
271 Inform GDBserver of an environment variable that is to be passed to
272 the inferior when starting it.
275 Inform GDBserver of an environment variable that is to be unset
276 before starting the remote inferior.
279 Inform GDBserver that the environment should be reset (i.e.,
280 user-set environment variables should be unset).
283 Indicates whether the inferior must be started with a shell or not.
286 Tell GDBserver that the inferior to be started should use a specific
289 * The "maintenance print c-tdesc" command now takes an optional
290 argument which is the file name of XML target description.
292 * The "maintenance selftest" command now takes an optional argument to
293 filter the tests to be run.
295 * The "enable", and "disable" commands now accept a range of
296 breakpoint locations, e.g. "enable 1.3-5".
301 Set and show the current working directory for the inferior.
304 Set and show compilation command used for compiling and injecting code
305 with the 'compile' commands.
307 set debug separate-debug-file
308 show debug separate-debug-file
309 Control the display of debug output about separate debug file search.
311 set dump-excluded-mappings
312 show dump-excluded-mappings
313 Control whether mappings marked with the VM_DONTDUMP flag should be
314 dumped when generating a core file.
317 List the registered selftests.
320 Start the debugged program stopping at the first instruction.
323 Control display of debugging messages related to OpenRISC targets.
325 set|show print type nested-type-limit
326 Set and show the limit of nesting level for nested types that the
327 type printer will show.
329 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
332 * Safer/improved support for debugging with no debug info
334 GDB no longer assumes functions with no debug information return
337 This means that GDB now refuses to call such functions unless you
338 tell it the function's type, by either casting the call to the
339 declared return type, or by casting the function to a function
340 pointer of the right type, and calling that:
342 (gdb) p getenv ("PATH")
343 'getenv' has unknown return type; cast the call to its declared return type
344 (gdb) p (char *) getenv ("PATH")
345 $1 = 0x7fffffffe "/usr/local/bin:/"...
346 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
347 $2 = 0x7fffffffe "/usr/local/bin:/"...
349 Similarly, GDB no longer assumes that global variables with no debug
350 info have type 'int', and refuses to print the variable's value
351 unless you tell it the variable's type:
354 'var' has unknown type; cast it to its declared type
358 * New native configurations
360 FreeBSD/aarch64 aarch64*-*-freebsd*
361 FreeBSD/arm arm*-*-freebsd*
365 FreeBSD/aarch64 aarch64*-*-freebsd*
366 FreeBSD/arm arm*-*-freebsd*
367 OpenRISC ELF or1k*-*-elf
369 * Removed targets and native configurations
371 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
373 *** Changes in GDB 8.0
375 * GDB now supports access to the PKU register on GNU/Linux. The register is
376 added by the Memory Protection Keys for Userspace feature which will be
377 available in future Intel CPUs.
379 * GDB now supports C++11 rvalue references.
383 ** New functions to start, stop and access a running btrace recording.
384 ** Rvalue references are now supported in gdb.Type.
386 * GDB now supports recording and replaying rdrand and rdseed Intel 64
389 * Building GDB and GDBserver now requires a C++11 compiler.
391 For example, GCC 4.8 or later.
393 It is no longer possible to build GDB or GDBserver with a C
394 compiler. The --disable-build-with-cxx configure option has been
397 * Building GDB and GDBserver now requires GNU make >= 3.81.
399 It is no longer supported to build GDB or GDBserver with another
400 implementation of the make program or an earlier version of GNU make.
402 * Native debugging on MS-Windows supports command-line redirection
404 Command-line arguments used for starting programs on MS-Windows can
405 now include redirection symbols supported by native Windows shells,
406 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
407 as "run", "start", and "set args", as well as the corresponding MI
410 * Support for thread names on MS-Windows.
412 GDB now catches and handles the special exception that programs
413 running on MS-Windows use to assign names to threads in the
416 * Support for Java programs compiled with gcj has been removed.
418 * User commands now accept an unlimited number of arguments.
419 Previously, only up to 10 was accepted.
421 * The "eval" command now expands user-defined command arguments.
423 This makes it easier to process a variable number of arguments:
428 eval "print $arg%d", $i
433 * Target descriptions can now describe registers for sparc32 and sparc64.
435 * GDB now supports DWARF version 5 (debug information format).
436 Its .debug_names index is not yet supported.
438 * New native configurations
440 FreeBSD/mips mips*-*-freebsd
444 Synopsys ARC arc*-*-elf32
445 FreeBSD/mips mips*-*-freebsd
447 * Removed targets and native configurations
449 Alpha running FreeBSD alpha*-*-freebsd*
450 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
455 Erases all the flash memory regions reported by the target.
457 maint print arc arc-instruction address
458 Print internal disassembler information about instruction at a given address.
462 set disassembler-options
463 show disassembler-options
464 Controls the passing of target specific information to the disassembler.
465 If it is necessary to specify more than one disassembler option then
466 multiple options can be placed together into a comma separated list.
467 The default value is the empty string. Currently, the only supported
468 targets are ARM, PowerPC and S/390.
473 Erases all the flash memory regions reported by the target. This is
474 equivalent to the CLI command flash-erase.
476 -file-list-shared-libraries
477 List the shared libraries in the program. This is
478 equivalent to the CLI command "info shared".
481 Catchpoints stopping the program when Ada exceptions are
482 handled. This is equivalent to the CLI command "catch handlers".
484 *** Changes in GDB 7.12
486 * GDB and GDBserver now build with a C++ compiler by default.
488 The --enable-build-with-cxx configure option is now enabled by
489 default. One must now explicitly configure with
490 --disable-build-with-cxx in order to build with a C compiler. This
491 option will be removed in a future release.
493 * GDBserver now supports recording btrace without maintaining an active
496 * GDB now supports a negative repeat count in the 'x' command to examine
497 memory backward from the given address. For example:
500 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
501 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
502 (gdb) x/-5i 0x0000000000400580
503 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
504 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
505 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
506 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
507 0x40057b <main(int, char**)+25>:
508 callq 0x400536 <Func1(int, char const*)>
510 * Fortran: Support structures with fields of dynamic types and
511 arrays of dynamic types.
513 * The symbol dumping maintenance commands have new syntax.
514 maint print symbols [-pc address] [--] [filename]
515 maint print symbols [-objfile objfile] [-source source] [--] [filename]
516 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
517 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
518 maint print msymbols [-objfile objfile] [--] [filename]
520 * GDB now supports multibit bitfields and enums in target register
523 * New Python-based convenience function $_as_string(val), which returns
524 the textual representation of a value. This function is especially
525 useful to obtain the text label of an enum value.
527 * Intel MPX bound violation handling.
529 Segmentation faults caused by a Intel MPX boundary violation
530 now display the kind of violation (upper or lower), the memory
531 address accessed and the memory bounds, along with the usual
532 signal received and code location.
536 Program received signal SIGSEGV, Segmentation fault
537 Upper bound violation while accessing address 0x7fffffffc3b3
538 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
539 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
541 * Rust language support.
542 GDB now supports debugging programs written in the Rust programming
543 language. See https://www.rust-lang.org/ for more information about
546 * Support for running interpreters on specified input/output devices
548 GDB now supports a new mechanism that allows frontends to provide
549 fully featured GDB console views, as a better alternative to
550 building such views on top of the "-interpreter-exec console"
551 command. See the new "new-ui" command below. With that command,
552 frontends can now start GDB in the traditional command-line mode
553 running in an embedded terminal emulator widget, and create a
554 separate MI interpreter running on a specified i/o device. In this
555 way, GDB handles line editing, history, tab completion, etc. in the
556 console all by itself, and the GUI uses the separate MI interpreter
557 for its own control and synchronization, invisible to the command
560 * The "catch syscall" command catches groups of related syscalls.
562 The "catch syscall" command now supports catching a group of related
563 syscalls using the 'group:' or 'g:' prefix.
568 skip -gfile file-glob-pattern
569 skip -function function
570 skip -rfunction regular-expression
571 A generalized form of the skip command, with new support for
572 glob-style file names and regular expressions for function names.
573 Additionally, a file spec and a function spec may now be combined.
575 maint info line-table REGEXP
576 Display the contents of GDB's internal line table data struture.
579 Run any GDB unit tests that were compiled in.
582 Start a new user interface instance running INTERP as interpreter,
583 using the TTY file for input/output.
587 ** gdb.Breakpoint objects have a new attribute "pending", which
588 indicates whether the breakpoint is pending.
589 ** Three new breakpoint-related events have been added:
590 gdb.breakpoint_created, gdb.breakpoint_modified, and
591 gdb.breakpoint_deleted.
594 Signal ("set") the given MS-Windows event object. This is used in
595 conjunction with the Windows JIT debugging (AeDebug) support, where
596 the OS suspends a crashing process until a debugger can attach to
597 it. Resuming the crashing process, in order to debug it, is done by
600 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
601 was added in GDBserver, including JIT compiling fast tracepoint's
602 conditional expression bytecode into native code.
604 * Support for various remote target protocols and ROM monitors has
607 target m32rsdi Remote M32R debugging over SDI
608 target mips MIPS remote debugging protocol
609 target pmon PMON ROM monitor
610 target ddb NEC's DDB variant of PMON for Vr4300
611 target rockhopper NEC RockHopper variant of PMON
612 target lsi LSI variant of PMO
614 * Support for tracepoints and fast tracepoints on powerpc-linux,
615 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
616 including JIT compiling fast tracepoint's conditional expression
617 bytecode into native code.
619 * MI async record =record-started now includes the method and format used for
620 recording. For example:
622 =record-started,thread-group="i1",method="btrace",format="bts"
624 * MI async record =thread-selected now includes the frame field. For example:
626 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
630 Andes NDS32 nds32*-*-elf
632 *** Changes in GDB 7.11
634 * GDB now supports debugging kernel-based threads on FreeBSD.
636 * Per-inferior thread numbers
638 Thread numbers are now per inferior instead of global. If you're
639 debugging multiple inferiors, GDB displays thread IDs using a
640 qualified INF_NUM.THR_NUM form. For example:
644 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
645 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
646 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
647 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
649 As consequence, thread numbers as visible in the $_thread
650 convenience variable and in Python's InferiorThread.num attribute
651 are no longer unique between inferiors.
653 GDB now maintains a second thread ID per thread, referred to as the
654 global thread ID, which is the new equivalent of thread numbers in
655 previous releases. See also $_gthread below.
657 For backwards compatibility, MI's thread IDs always refer to global
660 * Commands that accept thread IDs now accept the qualified
661 INF_NUM.THR_NUM form as well. For example:
664 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
667 * In commands that accept a list of thread IDs, you can now refer to
668 all threads of an inferior using a star wildcard. GDB accepts
669 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
670 refer to all threads of the current inferior. For example, "info
673 * You can use "info threads -gid" to display the global thread ID of
676 * The new convenience variable $_gthread holds the global number of
679 * The new convenience variable $_inferior holds the number of the
682 * GDB now displays the ID and name of the thread that hit a breakpoint
683 or received a signal, if your program is multi-threaded. For
686 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
687 Thread 1 "main" received signal SIGINT, Interrupt.
689 * Record btrace now supports non-stop mode.
691 * Support for tracepoints on aarch64-linux was added in GDBserver.
693 * The 'record instruction-history' command now indicates speculative execution
694 when using the Intel Processor Trace recording format.
696 * GDB now allows users to specify explicit locations, bypassing
697 the linespec parser. This feature is also available to GDB/MI
700 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
701 GDB now is able to debug both AArch64 applications and ARM applications
704 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
705 including JIT compiling fast tracepoint's conditional expression bytecode
708 * GDB now supports displaced stepping on AArch64 GNU/Linux.
710 * "info threads", "info inferiors", "info display", "info checkpoints"
711 and "maint info program-spaces" now list the corresponding items in
712 ascending ID order, for consistency with all other "info" commands.
714 * In Ada, the overloads selection menu has been enhanced to display the
715 parameter types and the return types for the matching overloaded subprograms.
719 maint set target-non-stop (on|off|auto)
720 maint show target-non-stop
721 Control whether GDB targets always operate in non-stop mode even if
722 "set non-stop" is "off". The default is "auto", meaning non-stop
723 mode is enabled if supported by the target.
725 maint set bfd-sharing
726 maint show bfd-sharing
727 Control the reuse of bfd objects.
731 Control display of debugging info regarding bfd caching.
735 Control display of debugging info regarding FreeBSD threads.
737 set remote multiprocess-extensions-packet
738 show remote multiprocess-extensions-packet
739 Set/show the use of the remote protocol multiprocess extensions.
741 set remote thread-events
742 show remote thread-events
743 Set/show the use of thread create/exit events.
745 set ada print-signatures on|off
746 show ada print-signatures"
747 Control whether parameter types and return types are displayed in overloads
748 selection menus. It is activaled (@code{on}) by default.
752 Controls the maximum size of memory, in bytes, that GDB will
753 allocate for value contents. Prevents incorrect programs from
754 causing GDB to allocate overly large buffers. Default is 64k.
756 * The "disassemble" command accepts a new modifier: /s.
757 It prints mixed source+disassembly like /m with two differences:
758 - disassembled instructions are now printed in program order, and
759 - and source for all relevant files is now printed.
760 The "/m" option is now considered deprecated: its "source-centric"
761 output hasn't proved useful in practice.
763 * The "record instruction-history" command accepts a new modifier: /s.
764 It behaves exactly like /m and prints mixed source+disassembly.
766 * The "set scheduler-locking" command supports a new mode "replay".
767 It behaves like "off" in record mode and like "on" in replay mode.
769 * Support for various ROM monitors has been removed:
771 target dbug dBUG ROM monitor for Motorola ColdFire
772 target picobug Motorola picobug monitor
773 target dink32 DINK32 ROM monitor for PowerPC
774 target m32r Renesas M32R/D ROM monitor
775 target mon2000 mon2000 ROM monitor
776 target ppcbug PPCBUG ROM monitor for PowerPC
778 * Support for reading/writing memory and extracting values on architectures
779 whose memory is addressable in units of any integral multiple of 8 bits.
782 Allows to break when an Ada exception is handled.
787 Indicates that an exec system call was executed.
789 exec-events feature in qSupported
790 The qSupported packet allows GDB to request support for exec
791 events using the new 'gdbfeature' exec-event, and the qSupported
792 response can contain the corresponding 'stubfeature'. Set and
793 show commands can be used to display whether these features are enabled.
796 Equivalent to interrupting with the ^C character, but works in
799 thread created stop reason (T05 create:...)
800 Indicates that the thread was just created and is stopped at entry.
802 thread exit stop reply (w exitcode;tid)
803 Indicates that the thread has terminated.
806 Enables/disables thread create and exit event reporting. For
807 example, this is used in non-stop mode when GDB stops a set of
808 threads and synchronously waits for the their corresponding stop
809 replies. Without exit events, if one of the threads exits, GDB
810 would hang forever not knowing that it should no longer expect a
811 stop for that same thread.
814 Indicates that there are no resumed threads left in the target (all
815 threads are stopped). The remote stub reports support for this stop
816 reply to GDB's qSupported query.
819 Enables/disables catching syscalls from the inferior process.
820 The remote stub reports support for this packet to GDB's qSupported query.
822 syscall_entry stop reason
823 Indicates that a syscall was just called.
825 syscall_return stop reason
826 Indicates that a syscall just returned.
828 * Extended-remote exec events
830 ** GDB now has support for exec events on extended-remote Linux targets.
831 For such targets with Linux kernels 2.5.46 and later, this enables
832 follow-exec-mode and exec catchpoints.
834 set remote exec-event-feature-packet
835 show remote exec-event-feature-packet
836 Set/show the use of the remote exec event feature.
838 * Thread names in remote protocol
840 The reply to qXfer:threads:read may now include a name attribute for each
843 * Target remote mode fork and exec events
845 ** GDB now has support for fork and exec events on target remote mode
846 Linux targets. For such targets with Linux kernels 2.5.46 and later,
847 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
848 fork and exec catchpoints.
850 * Remote syscall events
852 ** GDB now has support for catch syscall on remote Linux targets,
853 currently enabled on x86/x86_64 architectures.
855 set remote catch-syscall-packet
856 show remote catch-syscall-packet
857 Set/show the use of the remote catch syscall feature.
861 ** The -var-set-format command now accepts the zero-hexadecimal
862 format. It outputs data in hexadecimal format with zero-padding on the
867 ** gdb.InferiorThread objects have a new attribute "global_num",
868 which refers to the thread's global thread ID. The existing
869 "num" attribute now refers to the thread's per-inferior number.
870 See "Per-inferior thread numbers" above.
871 ** gdb.InferiorThread objects have a new attribute "inferior", which
872 is the Inferior object the thread belongs to.
874 *** Changes in GDB 7.10
876 * Support for process record-replay and reverse debugging on aarch64*-linux*
877 targets has been added. GDB now supports recording of A64 instruction set
878 including advance SIMD instructions.
880 * Support for Sun's version of the "stabs" debug file format has been removed.
882 * GDB now honors the content of the file /proc/PID/coredump_filter
883 (PID is the process ID) on GNU/Linux systems. This file can be used
884 to specify the types of memory mappings that will be included in a
885 corefile. For more information, please refer to the manual page of
886 "core(5)". GDB also has a new command: "set use-coredump-filter
887 on|off". It allows to set whether GDB will read the content of the
888 /proc/PID/coredump_filter file when generating a corefile.
890 * The "info os" command on GNU/Linux can now display information on
892 "info os cpus" Listing of all cpus/cores on the system
894 * GDB has two new commands: "set serial parity odd|even|none" and
895 "show serial parity". These allows to set or show parity for the
898 * The "info source" command now displays the producer string if it was
899 present in the debug info. This typically includes the compiler version
900 and may include things like its command line arguments.
902 * The "info dll", an alias of the "info sharedlibrary" command,
903 is now available on all platforms.
905 * Directory names supplied to the "set sysroot" commands may be
906 prefixed with "target:" to tell GDB to access shared libraries from
907 the target system, be it local or remote. This replaces the prefix
908 "remote:". The default sysroot has been changed from "" to
909 "target:". "remote:" is automatically converted to "target:" for
910 backward compatibility.
912 * The system root specified by "set sysroot" will be prepended to the
913 filename of the main executable (if reported to GDB as absolute by
914 the operating system) when starting processes remotely, and when
915 attaching to already-running local or remote processes.
917 * GDB now supports automatic location and retrieval of executable
918 files from remote targets. Remote debugging can now be initiated
919 using only a "target remote" or "target extended-remote" command
920 (no "set sysroot" or "file" commands are required). See "New remote
923 * The "dump" command now supports verilog hex format.
925 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
927 * On GNU/Linux, GDB and gdbserver are now able to access executable
928 and shared library files without a "set sysroot" command when
929 attaching to processes running in different mount namespaces from
930 the debugger. This makes it possible to attach to processes in
931 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
932 See "New remote packets" below.
934 * The "tui reg" command now provides completion for all of the
935 available register groups, including target specific groups.
937 * The HISTSIZE environment variable is no longer read when determining
938 the size of GDB's command history. GDB now instead reads the dedicated
939 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
940 disables truncation of command history. Non-numeric values of GDBHISTSIZE
945 ** Memory ports can now be unbuffered.
949 ** gdb.Objfile objects have a new attribute "username",
950 which is the name of the objfile as specified by the user,
951 without, for example, resolving symlinks.
952 ** You can now write frame unwinders in Python.
953 ** gdb.Type objects have a new method "optimized_out",
954 returning optimized out gdb.Value instance of this type.
955 ** gdb.Value objects have new methods "reference_value" and
956 "const_value" which return a reference to the value and a
957 "const" version of the value respectively.
961 maint print symbol-cache
962 Print the contents of the symbol cache.
964 maint print symbol-cache-statistics
965 Print statistics of symbol cache usage.
967 maint flush-symbol-cache
968 Flush the contents of the symbol cache.
972 Start branch trace recording using Branch Trace Store (BTS) format.
975 Evaluate expression by using the compiler and print result.
979 Explicit commands for enabling and disabling tui mode.
982 set mpx bound on i386 and amd64
983 Support for bound table investigation on Intel MPX enabled applications.
987 Start branch trace recording using Intel Processor Trace format.
990 Print information about branch tracing internals.
992 maint btrace packet-history
993 Print the raw branch tracing data.
995 maint btrace clear-packet-history
996 Discard the stored raw branch tracing data.
999 Discard all branch tracing data. It will be fetched and processed
1000 anew by the next "record" command.
1005 Renamed from "set debug dwarf2-die".
1006 show debug dwarf-die
1007 Renamed from "show debug dwarf2-die".
1009 set debug dwarf-read
1010 Renamed from "set debug dwarf2-read".
1011 show debug dwarf-read
1012 Renamed from "show debug dwarf2-read".
1014 maint set dwarf always-disassemble
1015 Renamed from "maint set dwarf2 always-disassemble".
1016 maint show dwarf always-disassemble
1017 Renamed from "maint show dwarf2 always-disassemble".
1019 maint set dwarf max-cache-age
1020 Renamed from "maint set dwarf2 max-cache-age".
1021 maint show dwarf max-cache-age
1022 Renamed from "maint show dwarf2 max-cache-age".
1024 set debug dwarf-line
1025 show debug dwarf-line
1026 Control display of debugging info regarding DWARF line processing.
1029 show max-completions
1030 Set the maximum number of candidates to be considered during
1031 completion. The default value is 200. This limit allows GDB
1032 to avoid generating large completion lists, the computation of
1033 which can cause the debugger to become temporarily unresponsive.
1035 set history remove-duplicates
1036 show history remove-duplicates
1037 Control the removal of duplicate history entries.
1039 maint set symbol-cache-size
1040 maint show symbol-cache-size
1041 Control the size of the symbol cache.
1043 set|show record btrace bts buffer-size
1044 Set and show the size of the ring buffer used for branch tracing in
1046 The obtained size may differ from the requested size. Use "info
1047 record" to see the obtained buffer size.
1049 set debug linux-namespaces
1050 show debug linux-namespaces
1051 Control display of debugging info regarding Linux namespaces.
1053 set|show record btrace pt buffer-size
1054 Set and show the size of the ring buffer used for branch tracing in
1055 Intel Processor Trace format.
1056 The obtained size may differ from the requested size. Use "info
1057 record" to see the obtained buffer size.
1059 maint set|show btrace pt skip-pad
1060 Set and show whether PAD packets are skipped when computing the
1063 * The command 'thread apply all' can now support new option '-ascending'
1064 to call its specified command for all threads in ascending order.
1066 * Python/Guile scripting
1068 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1069 special section named `.debug_gdb_scripts'.
1071 * New remote packets
1073 qXfer:btrace-conf:read
1074 Return the branch trace configuration for the current thread.
1076 Qbtrace-conf:bts:size
1077 Set the requested ring buffer size for branch tracing in BTS format.
1080 Enable Intel Procesor Trace-based branch tracing for the current
1081 process. The remote stub reports support for this packet to GDB's
1084 Qbtrace-conf:pt:size
1085 Set the requested ring buffer size for branch tracing in Intel Processor
1089 Indicates a memory breakpoint instruction was executed, irrespective
1090 of whether it was GDB that planted the breakpoint or the breakpoint
1091 is hardcoded in the program. This is required for correct non-stop
1095 Indicates the target stopped for a hardware breakpoint. This is
1096 required for correct non-stop mode operation.
1099 Return information about files on the remote system.
1101 qXfer:exec-file:read
1102 Return the full absolute name of the file that was executed to
1103 create a process running on the remote system.
1106 Select the filesystem on which vFile: operations with filename
1107 arguments will operate. This is required for GDB to be able to
1108 access files on remote targets where the remote stub does not
1109 share a common filesystem with the inferior(s).
1112 Indicates that a fork system call was executed.
1115 Indicates that a vfork system call was executed.
1117 vforkdone stop reason
1118 Indicates that a vfork child of the specified process has executed
1119 an exec or exit, allowing the vfork parent to resume execution.
1121 fork-events and vfork-events features in qSupported
1122 The qSupported packet allows GDB to request support for fork and
1123 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1124 and the qSupported response can contain the corresponding
1125 'stubfeatures'. Set and show commands can be used to display
1126 whether these features are enabled.
1128 * Extended-remote fork events
1130 ** GDB now has support for fork events on extended-remote Linux
1131 targets. For targets with Linux kernels 2.5.60 and later, this
1132 enables follow-fork-mode and detach-on-fork for both fork and
1133 vfork, as well as fork and vfork catchpoints.
1135 * The info record command now shows the recording format and the
1136 branch tracing configuration for the current thread when using
1137 the btrace record target.
1138 For the BTS format, it shows the ring buffer size.
1140 * GDB now has support for DTrace USDT (Userland Static Defined
1141 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1143 * GDB now supports access to vector registers on S/390 GNU/Linux
1146 * Removed command line options
1148 -xdb HP-UX XDB compatibility mode.
1150 * Removed targets and native configurations
1152 HP/PA running HP-UX hppa*-*-hpux*
1153 Itanium running HP-UX ia64-*-hpux*
1155 * New configure options
1158 This configure option allows the user to build GDB with support for
1159 Intel Processor Trace (default: auto). This requires libipt.
1161 --with-libipt-prefix=PATH
1162 Specify the path to the version of libipt that GDB should use.
1163 $PATH/include should contain the intel-pt.h header and
1164 $PATH/lib should contain the libipt.so library.
1166 *** Changes in GDB 7.9.1
1170 ** Xmethods can now specify a result type.
1172 *** Changes in GDB 7.9
1174 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1178 ** You can now access frame registers from Python scripts.
1179 ** New attribute 'producer' for gdb.Symtab objects.
1180 ** gdb.Objfile objects have a new attribute "progspace",
1181 which is the gdb.Progspace object of the containing program space.
1182 ** gdb.Objfile objects have a new attribute "owner".
1183 ** gdb.Objfile objects have a new attribute "build_id",
1184 which is the build ID generated when the file was built.
1185 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1186 ** A new event "gdb.clear_objfiles" has been added, triggered when
1187 selecting a new file to debug.
1188 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1189 ** New function gdb.lookup_objfile.
1191 New events which are triggered when GDB modifies the state of the
1194 ** gdb.events.inferior_call_pre: Function call is about to be made.
1195 ** gdb.events.inferior_call_post: Function call has just been made.
1196 ** gdb.events.memory_changed: A memory location has been altered.
1197 ** gdb.events.register_changed: A register has been altered.
1199 * New Python-based convenience functions:
1201 ** $_caller_is(name [, number_of_frames])
1202 ** $_caller_matches(regexp [, number_of_frames])
1203 ** $_any_caller_is(name [, number_of_frames])
1204 ** $_any_caller_matches(regexp [, number_of_frames])
1206 * GDB now supports the compilation and injection of source code into
1207 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1208 to compile the source code to object code, and if successful, inject
1209 and execute that code within the current context of the inferior.
1210 Currently the C language is supported. The commands used to
1211 interface with this new feature are:
1213 compile code [-raw|-r] [--] [source code]
1214 compile file [-raw|-r] filename
1218 demangle [-l language] [--] name
1219 Demangle "name" in the specified language, or the current language
1220 if elided. This command is renamed from the "maint demangle" command.
1221 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1222 as "maint demangler-warning".
1224 queue-signal signal-name-or-number
1225 Queue a signal to be delivered to the thread when it is resumed.
1227 add-auto-load-scripts-directory directory
1228 Add entries to the list of directories from which to load auto-loaded
1231 maint print user-registers
1232 List all currently available "user" registers.
1234 compile code [-r|-raw] [--] [source code]
1235 Compile, inject, and execute in the inferior the executable object
1236 code produced by compiling the provided source code.
1238 compile file [-r|-raw] filename
1239 Compile and inject into the inferior the executable object code
1240 produced by compiling the source code stored in the filename
1243 * On resume, GDB now always passes the signal the program had stopped
1244 for to the thread the signal was sent to, even if the user changed
1245 threads before resuming. Previously GDB would often (but not
1246 always) deliver the signal to the thread that happens to be current
1249 * Conversely, the "signal" command now consistently delivers the
1250 requested signal to the current thread. GDB now asks for
1251 confirmation if the program had stopped for a signal and the user
1252 switched threads meanwhile.
1254 * "breakpoint always-inserted" modes "off" and "auto" merged.
1256 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1257 won't remove breakpoints from the target until all threads stop,
1258 even in non-stop mode. The "auto" mode has been removed, and "off"
1259 is now the default mode.
1263 set debug symbol-lookup
1264 show debug symbol-lookup
1265 Control display of debugging info regarding symbol lookup.
1269 ** The -list-thread-groups command outputs an exit-code field for
1270 inferiors that have exited.
1274 MIPS SDE mips*-sde*-elf*
1278 Support for these obsolete configurations has been removed.
1280 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1281 SGI Irix-5.x mips-*-irix5*
1282 SGI Irix-6.x mips-*-irix6*
1283 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1284 VAX running Ultrix vax-*-ultrix*
1286 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1287 and "assf"), have been removed. Use the "sharedlibrary" command, or
1288 its alias "share", instead.
1290 *** Changes in GDB 7.8
1292 * New command line options
1295 This is an alias for the --data-directory option.
1297 * GDB supports printing and modifying of variable length automatic arrays
1298 as specified in ISO C99.
1300 * The ARM simulator now supports instruction level tracing
1301 with or without disassembly.
1305 GDB now has support for scripting using Guile. Whether this is
1306 available is determined at configure time.
1307 Guile version 2.0 or greater is required.
1308 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1310 * New commands (for set/show, see "New options" below)
1314 Invoke CODE by passing it to the Guile interpreter.
1318 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1320 info auto-load guile-scripts [regexp]
1321 Print the list of automatically loaded Guile scripts.
1323 * The source command is now capable of sourcing Guile scripts.
1324 This feature is dependent on the debugger being built with Guile support.
1328 set print symbol-loading (off|brief|full)
1329 show print symbol-loading
1330 Control whether to print informational messages when loading symbol
1331 information for a file. The default is "full", but when debugging
1332 programs with large numbers of shared libraries the amount of output
1333 becomes less useful.
1335 set guile print-stack (none|message|full)
1336 show guile print-stack
1337 Show a stack trace when an error is encountered in a Guile script.
1339 set auto-load guile-scripts (on|off)
1340 show auto-load guile-scripts
1341 Control auto-loading of Guile script files.
1343 maint ada set ignore-descriptive-types (on|off)
1344 maint ada show ignore-descriptive-types
1345 Control whether the debugger should ignore descriptive types in Ada
1346 programs. The default is not to ignore the descriptive types. See
1347 the user manual for more details on descriptive types and the intended
1348 usage of this option.
1350 set auto-connect-native-target
1352 Control whether GDB is allowed to automatically connect to the
1353 native target for the run, attach, etc. commands when not connected
1354 to any target yet. See also "target native" below.
1356 set record btrace replay-memory-access (read-only|read-write)
1357 show record btrace replay-memory-access
1358 Control what memory accesses are allowed during replay.
1360 maint set target-async (on|off)
1361 maint show target-async
1362 This controls whether GDB targets operate in synchronous or
1363 asynchronous mode. Normally the default is asynchronous, if it is
1364 available; but this can be changed to more easily debug problems
1365 occurring only in synchronous mode.
1367 set mi-async (on|off)
1369 Control whether MI asynchronous mode is preferred. This supersedes
1370 "set target-async" of previous GDB versions.
1372 * "set target-async" is deprecated as a CLI option and is now an alias
1373 for "set mi-async" (only puts MI into async mode).
1375 * Background execution commands (e.g., "c&", "s&", etc.) are now
1376 possible ``out of the box'' if the target supports them. Previously
1377 the user would need to explicitly enable the possibility with the
1378 "set target-async on" command.
1380 * New features in the GDB remote stub, GDBserver
1382 ** New option --debug-format=option1[,option2,...] allows one to add
1383 additional text to each output. At present only timestamps
1384 are supported: --debug-format=timestamps.
1385 Timestamps can also be turned on with the
1386 "monitor set debug-format timestamps" command from GDB.
1388 * The 'record instruction-history' command now starts counting instructions
1389 at one. This also affects the instruction ranges reported by the
1390 'record function-call-history' command when given the /i modifier.
1392 * The command 'record function-call-history' supports a new modifier '/c' to
1393 indent the function names based on their call stack depth.
1394 The fields for the '/i' and '/l' modifier have been reordered.
1395 The source line range is now prefixed with 'at'.
1396 The instruction range is now prefixed with 'inst'.
1397 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1398 "record instruction-history" and "list" commands.
1400 * The ranges given as arguments to the 'record function-call-history' and
1401 'record instruction-history' commands are now inclusive.
1403 * The btrace record target now supports the 'record goto' command.
1404 For locations inside the execution trace, the back trace is computed
1405 based on the information stored in the execution trace.
1407 * The btrace record target supports limited reverse execution and replay.
1408 The target does not record data and therefore does not allow reading
1409 memory or registers.
1411 * The "catch syscall" command now works on s390*-linux* targets.
1413 * The "compare-sections" command is no longer specific to target
1414 remote. It now works with all targets.
1416 * All native targets are now consistently called "native".
1417 Consequently, the "target child", "target GNU", "target djgpp",
1418 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1419 commands have been replaced with "target native". The QNX/NTO port
1420 leaves the "procfs" target in place and adds a "native" target for
1421 consistency with other ports. The impact on users should be minimal
1422 as these commands previously either throwed an error, or were
1423 no-ops. The target's name is visible in the output of the following
1424 commands: "help target", "info target", "info files", "maint print
1427 * The "target native" command now connects to the native target. This
1428 can be used to launch native programs even when "set
1429 auto-connect-native-target" is set to off.
1431 * GDB now supports access to Intel MPX registers on GNU/Linux.
1433 * Support for Intel AVX-512 registers on GNU/Linux.
1434 Support displaying and modifying Intel AVX-512 registers
1435 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1437 * New remote packets
1439 qXfer:btrace:read's annex
1440 The qXfer:btrace:read packet supports a new annex 'delta' to read
1441 branch trace incrementally.
1445 ** Valid Python operations on gdb.Value objects representing
1446 structs/classes invoke the corresponding overloaded operators if
1448 ** New `Xmethods' feature in the Python API. Xmethods are
1449 additional methods or replacements for existing methods of a C++
1450 class. This feature is useful for those cases where a method
1451 defined in C++ source code could be inlined or optimized out by
1452 the compiler, making it unavailable to GDB.
1455 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1457 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1458 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1459 its alias "share", instead.
1461 * The commands "set remotebaud" and "show remotebaud" are no longer
1462 supported. Use "set serial baud" and "show serial baud" (respectively)
1467 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1468 target-async". The latter is left as a deprecated alias of the
1469 former for backward compatibility. If the target supports it,
1470 CLI background execution commands are now always possible by
1471 default, independently of whether the frontend stated a
1472 preference for asynchronous execution with "-gdb-set mi-async".
1473 Previously "-gdb-set target-async off" affected both MI execution
1474 commands and CLI execution commands.
1476 *** Changes in GDB 7.7
1478 * Improved support for process record-replay and reverse debugging on
1479 arm*-linux* targets. Support for thumb32 and syscall instruction
1480 recording has been added.
1482 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1484 * GDB now supports Fission DWP file format version 2.
1485 http://gcc.gnu.org/wiki/DebugFission
1487 * New convenience function "$_isvoid", to check whether an expression
1488 is void. A void expression is an expression where the type of the
1489 result is "void". For example, some convenience variables may be
1490 "void" when evaluated (e.g., "$_exitcode" before the execution of
1491 the program being debugged; or an undefined convenience variable).
1492 Another example, when calling a function whose return type is
1495 * The "maintenance print objfiles" command now takes an optional regexp.
1497 * The "catch syscall" command now works on arm*-linux* targets.
1499 * GDB now consistently shows "<not saved>" when printing values of
1500 registers the debug info indicates have not been saved in the frame
1501 and there's nowhere to retrieve them from
1502 (callee-saved/call-clobbered registers):
1507 (gdb) info registers rax
1510 Before, the former would print "<optimized out>", and the latter
1511 "*value not available*".
1513 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1518 ** Frame filters and frame decorators have been added.
1519 ** Temporary breakpoints are now supported.
1520 ** Line tables representation has been added.
1521 ** New attribute 'parent_type' for gdb.Field objects.
1522 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1523 ** New attribute 'name' for gdb.Type objects.
1527 Nios II ELF nios2*-*-elf
1528 Nios II GNU/Linux nios2*-*-linux
1529 Texas Instruments MSP430 msp430*-*-elf
1531 * Removed native configurations
1533 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1534 been removed. ELF variants of these configurations are kept supported.
1536 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1537 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1538 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1539 i[34567]86-*-openbsd3.[0-3]
1540 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1541 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1542 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1546 Like "catch throw", but catches a re-thrown exception.
1547 maint check-psymtabs
1548 Renamed from old "maint check-symtabs".
1550 Perform consistency checks on symtabs.
1551 maint expand-symtabs
1552 Expand symtabs matching an optional regexp.
1555 Display the details of GDB configure-time options.
1557 maint set|show per-command
1558 maint set|show per-command space
1559 maint set|show per-command time
1560 maint set|show per-command symtab
1561 Enable display of per-command gdb resource usage.
1563 remove-symbol-file FILENAME
1564 remove-symbol-file -a ADDRESS
1565 Remove a symbol file added via add-symbol-file. The file to remove
1566 can be identified by its filename or by an address that lies within
1567 the boundaries of this symbol file in memory.
1570 info exceptions REGEXP
1571 Display the list of Ada exceptions defined in the program being
1572 debugged. If provided, only the exceptions whose names match REGEXP
1577 set debug symfile off|on
1579 Control display of debugging info regarding reading symbol files and
1580 symbol tables within those files
1582 set print raw frame-arguments
1583 show print raw frame-arguments
1584 Set/show whether to print frame arguments in raw mode,
1585 disregarding any defined pretty-printers.
1587 set remote trace-status-packet
1588 show remote trace-status-packet
1589 Set/show the use of remote protocol qTStatus packet.
1593 Control display of debugging messages related to Nios II targets.
1597 Control whether target-assisted range stepping is enabled.
1599 set startup-with-shell
1600 show startup-with-shell
1601 Specifies whether Unix child processes are started via a shell or
1606 Use the target memory cache for accesses to the code segment. This
1607 improves performance of remote debugging (particularly disassembly).
1609 * You can now use a literal value 'unlimited' for options that
1610 interpret 0 or -1 as meaning "unlimited". E.g., "set
1611 trace-buffer-size unlimited" is now an alias for "set
1612 trace-buffer-size -1" and "set height unlimited" is now an alias for
1615 * The "set debug symtab-create" debugging option of GDB has been changed to
1616 accept a verbosity level. 0 means "off", 1 provides basic debugging
1617 output, and values of 2 or greater provides more verbose output.
1619 * New command-line options
1621 Display the details of GDB configure-time options.
1623 * The command 'tsave' can now support new option '-ctf' to save trace
1624 buffer in Common Trace Format.
1626 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1629 * GDB now implements the the C++ 'typeid' operator.
1631 * The new convenience variable $_exception holds the exception being
1632 thrown or caught at an exception-related catchpoint.
1634 * The exception-related catchpoints, like "catch throw", now accept a
1635 regular expression which can be used to filter exceptions by type.
1637 * The new convenience variable $_exitsignal is automatically set to
1638 the terminating signal number when the program being debugged dies
1639 due to an uncaught signal.
1643 ** All MI commands now accept an optional "--language" option.
1644 Support for this feature can be verified by using the "-list-features"
1645 command, which should contain "language-option".
1647 ** The new command -info-gdb-mi-command allows the user to determine
1648 whether a GDB/MI command is supported or not.
1650 ** The "^error" result record returned when trying to execute an undefined
1651 GDB/MI command now provides a variable named "code" whose content is the
1652 "undefined-command" error code. Support for this feature can be verified
1653 by using the "-list-features" command, which should contain
1654 "undefined-command-error-code".
1656 ** The -trace-save MI command can optionally save trace buffer in Common
1659 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1661 ** The command -data-list-register-values now accepts an optional
1662 "--skip-unavailable" option. When used, only the available registers
1665 ** The new command -trace-frame-collected dumps collected variables,
1666 computed expressions, tvars, memory and registers in a traceframe.
1668 ** The commands -stack-list-locals, -stack-list-arguments and
1669 -stack-list-variables now accept an option "--skip-unavailable".
1670 When used, only the available locals or arguments are displayed.
1672 ** The -exec-run command now accepts an optional "--start" option.
1673 When used, the command follows the same semantics as the "start"
1674 command, stopping the program's execution at the start of its
1675 main subprogram. Support for this feature can be verified using
1676 the "-list-features" command, which should contain
1677 "exec-run-start-option".
1679 ** The new commands -catch-assert and -catch-exceptions insert
1680 catchpoints stopping the program when Ada exceptions are raised.
1682 ** The new command -info-ada-exceptions provides the equivalent of
1683 the new "info exceptions" command.
1685 * New system-wide configuration scripts
1686 A GDB installation now provides scripts suitable for use as system-wide
1687 configuration scripts for the following systems:
1691 * GDB now supports target-assigned range stepping with remote targets.
1692 This improves the performance of stepping source lines by reducing
1693 the number of control packets from/to GDB. See "New remote packets"
1696 * GDB now understands the element 'tvar' in the XML traceframe info.
1697 It has the id of the collected trace state variables.
1699 * On S/390 targets that provide the transactional-execution feature,
1700 the program interruption transaction diagnostic block (TDB) is now
1701 represented as a number of additional "registers" in GDB.
1703 * New remote packets
1707 The vCont packet supports a new 'r' action, that tells the remote
1708 stub to step through an address range itself, without GDB
1709 involvemement at each single-step.
1711 qXfer:libraries-svr4:read's annex
1712 The previously unused annex of the qXfer:libraries-svr4:read packet
1713 is now used to support passing an argument list. The remote stub
1714 reports support for this argument list to GDB's qSupported query.
1715 The defined arguments are "start" and "prev", used to reduce work
1716 necessary for library list updating, resulting in significant
1719 * New features in the GDB remote stub, GDBserver
1721 ** GDBserver now supports target-assisted range stepping. Currently
1722 enabled on x86/x86_64 GNU/Linux targets.
1724 ** GDBserver now adds element 'tvar' in the XML in the reply to
1725 'qXfer:traceframe-info:read'. It has the id of the collected
1726 trace state variables.
1728 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1731 * New 'z' formatter for printing and examining memory, this displays the
1732 value as hexadecimal zero padded on the left to the size of the type.
1734 * GDB can now use Windows x64 unwinding data.
1736 * The "set remotebaud" command has been replaced by "set serial baud".
1737 Similarly, "show remotebaud" has been replaced by "show serial baud".
1738 The "set remotebaud" and "show remotebaud" commands are still available
1739 to provide backward compatibility with older versions of GDB.
1741 *** Changes in GDB 7.6
1743 * Target record has been renamed to record-full.
1744 Record/replay is now enabled with the "record full" command.
1745 This also affects settings that are associated with full record/replay
1746 that have been moved from "set/show record" to "set/show record full":
1748 set|show record full insn-number-max
1749 set|show record full stop-at-limit
1750 set|show record full memory-query
1752 * A new record target "record-btrace" has been added. The new target
1753 uses hardware support to record the control-flow of a process. It
1754 does not support replaying the execution, but it implements the
1755 below new commands for investigating the recorded execution log.
1756 This new recording method can be enabled using:
1760 The "record-btrace" target is only available on Intel Atom processors
1761 and requires a Linux kernel 2.6.32 or later.
1763 * Two new commands have been added for record/replay to give information
1764 about the recorded execution without having to replay the execution.
1765 The commands are only supported by "record btrace".
1767 record instruction-history prints the execution history at
1768 instruction granularity
1770 record function-call-history prints the execution history at
1771 function granularity
1773 * New native configurations
1775 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1776 FreeBSD/powerpc powerpc*-*-freebsd
1777 x86_64/Cygwin x86_64-*-cygwin*
1778 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1782 ARM AArch64 aarch64*-*-elf
1783 ARM AArch64 GNU/Linux aarch64*-*-linux
1784 Lynx 178 PowerPC powerpc-*-lynx*178
1785 x86_64/Cygwin x86_64-*-cygwin*
1786 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1788 * If the configured location of system.gdbinit file (as given by the
1789 --with-system-gdbinit option at configure time) is in the
1790 data-directory (as specified by --with-gdb-datadir at configure
1791 time) or in one of its subdirectories, then GDB will look for the
1792 system-wide init file in the directory specified by the
1793 --data-directory command-line option.
1795 * New command line options:
1797 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1798 other initialization files, unlike -nx which disables all of them.
1800 * Removed command line options
1802 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1805 * The 'ptype' and 'whatis' commands now accept an argument to control
1808 * 'info proc' now works on some core files.
1812 ** Vectors can be created with gdb.Type.vector.
1814 ** Python's atexit.register now works in GDB.
1816 ** Types can be pretty-printed via a Python API.
1818 ** Python 3 is now supported (in addition to Python 2.4 or later)
1820 ** New class gdb.Architecture exposes GDB's internal representation
1821 of architecture in the Python API.
1823 ** New method Frame.architecture returns the gdb.Architecture object
1824 corresponding to the frame's architecture.
1826 * New Python-based convenience functions:
1828 ** $_memeq(buf1, buf2, length)
1829 ** $_streq(str1, str2)
1831 ** $_regex(str, regex)
1833 * The 'cd' command now defaults to using '~' (the home directory) if not
1836 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1837 default for GCC since November 2000.
1839 * The command 'forward-search' can now be abbreviated as 'fo'.
1841 * The command 'info tracepoints' can now display 'installed on target'
1842 or 'not installed on target' for each non-pending location of tracepoint.
1844 * New configure options
1846 --enable-libmcheck/--disable-libmcheck
1847 By default, development versions are built with -lmcheck on hosts
1848 that support it, in order to help track memory corruption issues.
1849 Release versions, on the other hand, are built without -lmcheck
1850 by default. The --enable-libmcheck/--disable-libmcheck configure
1851 options allow the user to override that default.
1852 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1853 This configure option allows the user to build GDB with
1854 libbabeltrace using which GDB can read Common Trace Format data.
1856 * New commands (for set/show, see "New options" below)
1859 Catch signals. This is similar to "handle", but allows commands and
1860 conditions to be attached.
1863 List the BFDs known to GDB.
1865 python-interactive [command]
1867 Start a Python interactive prompt, or evaluate the optional command
1868 and print the result of expressions.
1871 "py" is a new alias for "python".
1873 enable type-printer [name]...
1874 disable type-printer [name]...
1875 Enable or disable type printers.
1879 ** For the Renesas Super-H architecture, the "regs" command has been removed
1880 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1885 set print type methods (on|off)
1886 show print type methods
1887 Control whether method declarations are displayed by "ptype".
1888 The default is to show them.
1890 set print type typedefs (on|off)
1891 show print type typedefs
1892 Control whether typedef definitions are displayed by "ptype".
1893 The default is to show them.
1895 set filename-display basename|relative|absolute
1896 show filename-display
1897 Control the way in which filenames is displayed.
1898 The default is "relative", which preserves previous behavior.
1900 set trace-buffer-size
1901 show trace-buffer-size
1902 Request target to change the size of trace buffer.
1904 set remote trace-buffer-size-packet auto|on|off
1905 show remote trace-buffer-size-packet
1906 Control the use of the remote protocol `QTBuffer:size' packet.
1910 Control display of debugging messages related to ARM AArch64.
1913 set debug coff-pe-read
1914 show debug coff-pe-read
1915 Control display of debugging messages related to reading of COFF/PE
1920 Control display of debugging messages related to Mach-O symbols
1923 set debug notification
1924 show debug notification
1925 Control display of debugging info for async remote notification.
1929 ** Command parameter changes are now notified using new async record
1930 "=cmd-param-changed".
1931 ** Trace frame changes caused by command "tfind" are now notified using
1932 new async record "=traceframe-changed".
1933 ** The creation, deletion and modification of trace state variables
1934 are now notified using new async records "=tsv-created",
1935 "=tsv-deleted" and "=tsv-modified".
1936 ** The start and stop of process record are now notified using new
1937 async record "=record-started" and "=record-stopped".
1938 ** Memory changes are now notified using new async record
1940 ** The data-disassemble command response will include a "fullname" field
1941 containing the absolute file name when source has been requested.
1942 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1943 command, to allow pattern filling of memory areas.
1944 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1945 library load/unload events.
1946 ** The response to breakpoint commands and breakpoint async records
1947 includes an "installed" field containing a boolean state about each
1948 non-pending tracepoint location is whether installed on target or not.
1949 ** Output of the "-trace-status" command includes a "trace-file" field
1950 containing the name of the trace file being examined. This field is
1951 optional, and only present when examining a trace file.
1952 ** The "fullname" field is now always present along with the "file" field,
1953 even if the file cannot be found by GDB.
1955 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1956 You must have the LZMA library available when configuring GDB for this
1957 feature to be enabled. For more information, see:
1958 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1960 * New remote packets
1963 Set the size of trace buffer. The remote stub reports support for this
1964 packet to gdb's qSupported query.
1967 Enable Branch Trace Store (BTS)-based branch tracing for the current
1968 thread. The remote stub reports support for this packet to gdb's
1972 Disable branch tracing for the current thread. The remote stub reports
1973 support for this packet to gdb's qSupported query.
1976 Read the traced branches for the current thread. The remote stub
1977 reports support for this packet to gdb's qSupported query.
1979 *** Changes in GDB 7.5
1981 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1982 for more x32 ABI info.
1984 * GDB now supports access to MIPS DSP registers on Linux targets.
1986 * GDB now supports debugging microMIPS binaries.
1988 * The "info os" command on GNU/Linux can now display information on
1989 several new classes of objects managed by the operating system:
1990 "info os procgroups" lists process groups
1991 "info os files" lists file descriptors
1992 "info os sockets" lists internet-domain sockets
1993 "info os shm" lists shared-memory regions
1994 "info os semaphores" lists semaphores
1995 "info os msg" lists message queues
1996 "info os modules" lists loaded kernel modules
1998 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1999 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2000 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2001 options and inspect the probe arguments using the new $_probe_arg family
2002 of convenience variables. You can obtain more information about SystemTap
2003 in <http://sourceware.org/systemtap/>.
2005 * GDB now supports reversible debugging on ARM, it allows you to
2006 debug basic ARM and THUMB instructions, and provides
2007 record/replay support.
2009 * The option "symbol-reloading" has been deleted as it is no longer used.
2013 ** GDB commands implemented in Python can now be put in command class
2016 ** The "maint set python print-stack on|off" is now deleted.
2018 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2019 apply "flag enum"-style pretty-printing to any enum.
2021 ** gdb.lookup_symbol can now work when there is no current frame.
2023 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2024 the source at which the symbol was defined.
2026 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2027 method 'value'. The former indicates whether the symbol needs a
2028 frame in order to compute its value, and the latter computes the
2031 ** A new method 'referenced_value' on gdb.Value objects which can
2032 dereference pointer as well as C++ reference values.
2034 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2035 which return the global and static blocks (as gdb.Block objects),
2036 of the underlying symbol table, respectively.
2038 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2039 object associated with a PC value.
2041 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2042 of the address range occupied by code for the current source line.
2044 * Go language support.
2045 GDB now supports debugging programs written in the Go programming
2048 * GDBserver now supports stdio connections.
2049 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2051 * The binary "gdbtui" can no longer be built or installed.
2052 Use "gdb -tui" instead.
2054 * GDB will now print "flag" enums specially. A flag enum is one where
2055 all the enumerator values have no bits in common when pairwise
2056 "and"ed. When printing a value whose type is a flag enum, GDB will
2057 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2058 (gdb) print (enum E) 3
2061 * The filename part of a linespec will now match trailing components
2062 of a source file name. For example, "break gcc/expr.c:1000" will
2063 now set a breakpoint in build/gcc/expr.c, but not
2064 build/libcpp/expr.c.
2066 * The "info proc" and "generate-core-file" commands will now also
2067 work on remote targets connected to GDBserver on Linux.
2069 * The command "info catch" has been removed. It has been disabled
2070 since December 2007.
2072 * The "catch exception" and "catch assert" commands now accept
2073 a condition at the end of the command, much like the "break"
2074 command does. For instance:
2076 (gdb) catch exception Constraint_Error if Barrier = True
2078 Previously, it was possible to add a condition to such catchpoints,
2079 but it had to be done as a second step, after the catchpoint had been
2080 created, using the "condition" command.
2082 * The "info static-tracepoint-marker" command will now also work on
2083 native Linux targets with in-process agent.
2085 * GDB can now set breakpoints on inlined functions.
2087 * The .gdb_index section has been updated to include symbols for
2088 inlined functions. GDB will ignore older .gdb_index sections by
2089 default, which could cause symbol files to be loaded more slowly
2090 until their .gdb_index sections can be recreated. The new command
2091 "set use-deprecated-index-sections on" will cause GDB to use any older
2092 .gdb_index sections it finds. This will restore performance, but the
2093 ability to set breakpoints on inlined functions will be lost in symbol
2094 files with older .gdb_index sections.
2096 The .gdb_index section has also been updated to record more information
2097 about each symbol. This speeds up the "info variables", "info functions"
2098 and "info types" commands when used with programs having the .gdb_index
2099 section, as well as speeding up debugging with shared libraries using
2100 the .gdb_index section.
2102 * Ada support for GDB/MI Variable Objects has been added.
2104 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2109 ** New command -info-os is the MI equivalent of "info os".
2111 ** Output logs ("set logging" and related) now include MI output.
2115 ** "set use-deprecated-index-sections on|off"
2116 "show use-deprecated-index-sections on|off"
2117 Controls the use of deprecated .gdb_index sections.
2119 ** "catch load" and "catch unload" can be used to stop when a shared
2120 library is loaded or unloaded, respectively.
2122 ** "enable count" can be used to auto-disable a breakpoint after
2125 ** "info vtbl" can be used to show the virtual method tables for
2126 C++ and Java objects.
2128 ** "explore" and its sub commands "explore value" and "explore type"
2129 can be used to recursively explore values and types of
2130 expressions. These commands are available only if GDB is
2131 configured with '--with-python'.
2133 ** "info auto-load" shows status of all kinds of auto-loaded files,
2134 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2135 sequences of commands files, "info auto-load python-scripts"
2136 shows status of auto-loading Python script files,
2137 "info auto-load local-gdbinit" shows status of loading init file
2138 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2139 status of inferior specific thread debugging shared library loading.
2141 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2142 and "show auto-load-scripts" commands have been deprecated, use their
2143 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2144 and "show auto-load python-scripts" counterparts instead.
2146 ** "dprintf location,format,args..." creates a dynamic printf, which
2147 is basically a breakpoint that does a printf and immediately
2148 resumes your program's execution, so it is like a printf that you
2149 can insert dynamically at runtime instead of at compiletime.
2151 ** "set print symbol"
2153 Controls whether GDB attempts to display the symbol, if any,
2154 corresponding to addresses it prints. This defaults to "on", but
2155 you can set it to "off" to restore GDB's previous behavior.
2157 * Deprecated commands
2159 ** For the Renesas Super-H architecture, the "regs" command has been
2160 deprecated, and "info all-registers" should be used instead.
2164 Renesas RL78 rl78-*-elf
2165 HP OpenVMS ia64 ia64-hp-openvms*
2167 * GDBserver supports evaluation of breakpoint conditions. When
2168 support is advertised by GDBserver, GDB may be told to send the
2169 breakpoint conditions in bytecode form to GDBserver. GDBserver
2170 will only report the breakpoint trigger to GDB when its condition
2175 set mips compression
2176 show mips compression
2177 Select the compressed ISA encoding used in functions that have no symbol
2178 information available. The encoding can be set to either of:
2181 and is updated automatically from ELF file flags if available.
2183 set breakpoint condition-evaluation
2184 show breakpoint condition-evaluation
2185 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2186 GDBserver ("target"). Default option "auto" chooses the most efficient
2188 This option can improve debugger efficiency depending on the speed of the
2192 Disable auto-loading globally.
2195 Show auto-loading setting of all kinds of auto-loaded files.
2197 set auto-load gdb-scripts on|off
2198 show auto-load gdb-scripts
2199 Control auto-loading of GDB canned sequences of commands files.
2201 set auto-load python-scripts on|off
2202 show auto-load python-scripts
2203 Control auto-loading of Python script files.
2205 set auto-load local-gdbinit on|off
2206 show auto-load local-gdbinit
2207 Control loading of init file (.gdbinit) from current directory.
2209 set auto-load libthread-db on|off
2210 show auto-load libthread-db
2211 Control auto-loading of inferior specific thread debugging shared library.
2213 set auto-load scripts-directory <dir1>[:<dir2>...]
2214 show auto-load scripts-directory
2215 Set a list of directories from which to load auto-loaded scripts.
2216 Automatically loaded Python scripts and GDB scripts are located in one
2217 of the directories listed by this option.
2218 The delimiter (':' above) may differ according to the host platform.
2220 set auto-load safe-path <dir1>[:<dir2>...]
2221 show auto-load safe-path
2222 Set a list of directories from which it is safe to auto-load files.
2223 The delimiter (':' above) may differ according to the host platform.
2225 set debug auto-load on|off
2226 show debug auto-load
2227 Control display of debugging info for auto-loading the files above.
2229 set dprintf-style gdb|call|agent
2231 Control the way in which a dynamic printf is performed; "gdb"
2232 requests a GDB printf command, while "call" causes dprintf to call a
2233 function in the inferior. "agent" requests that the target agent
2234 (such as GDBserver) do the printing.
2236 set dprintf-function <expr>
2237 show dprintf-function
2238 set dprintf-channel <expr>
2239 show dprintf-channel
2240 Set the function and optional first argument to the call when using
2241 the "call" style of dynamic printf.
2243 set disconnected-dprintf on|off
2244 show disconnected-dprintf
2245 Control whether agent-style dynamic printfs continue to be in effect
2246 after GDB disconnects.
2248 * New configure options
2250 --with-auto-load-dir
2251 Configure default value for the 'set auto-load scripts-directory'
2252 setting above. It defaults to '$debugdir:$datadir/auto-load',
2253 $debugdir representing global debugging info directories (available
2254 via 'show debug-file-directory') and $datadir representing GDB's data
2255 directory (available via 'show data-directory').
2257 --with-auto-load-safe-path
2258 Configure default value for the 'set auto-load safe-path' setting
2259 above. It defaults to the --with-auto-load-dir setting.
2261 --without-auto-load-safe-path
2262 Set 'set auto-load safe-path' to '/', effectively disabling this
2265 * New remote packets
2267 z0/z1 conditional breakpoints extension
2269 The z0/z1 breakpoint insertion packets have been extended to carry
2270 a list of conditional expressions over to the remote stub depending on the
2271 condition evaluation mode. The use of this extension can be controlled
2272 via the "set remote conditional-breakpoints-packet" command.
2276 Specify the signals which the remote stub may pass to the debugged
2277 program without GDB involvement.
2279 * New command line options
2281 --init-command=FILE, -ix Like --command, -x but execute it
2282 before loading inferior.
2283 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2284 execute it before loading inferior.
2286 *** Changes in GDB 7.4
2288 * GDB now handles ambiguous linespecs more consistently; the existing
2289 FILE:LINE support has been expanded to other types of linespecs. A
2290 breakpoint will now be set on all matching locations in all
2291 inferiors, and locations will be added or removed according to
2294 * GDB now allows you to skip uninteresting functions and files when
2295 stepping with the "skip function" and "skip file" commands.
2297 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2298 and "show remote hardware-watchpoint-length-limit". These allows to
2299 set or show the maximum length limit (in bytes) of a remote
2300 target hardware watchpoint.
2302 This allows e.g. to use "unlimited" hardware watchpoints with the
2303 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2304 watchpoints are slower than real hardware watchpoints but are
2305 significantly faster than gdb software watchpoints.
2309 ** The register_pretty_printer function in module gdb.printing now takes
2310 an optional `replace' argument. If True, the new printer replaces any
2313 ** The "maint set python print-stack on|off" command has been
2314 deprecated and will be deleted in GDB 7.5.
2315 A new command: "set python print-stack none|full|message" has
2316 replaced it. Additionally, the default for "print-stack" is
2317 now "message", which just prints the error message without
2320 ** A prompt substitution hook (prompt_hook) is now available to the
2323 ** A new Python module, gdb.prompt has been added to the GDB Python
2324 modules library. This module provides functionality for
2325 escape sequences in prompts (used by set/show
2326 extended-prompt). These escape sequences are replaced by their
2327 corresponding value.
2329 ** Python commands and convenience-functions located in
2330 'data-directory'/python/gdb/command and
2331 'data-directory'/python/gdb/function are now automatically loaded
2334 ** Blocks now provide four new attributes. global_block and
2335 static_block will return the global and static blocks
2336 respectively. is_static and is_global are boolean attributes
2337 that indicate if the block is one of those two types.
2339 ** Symbols now provide the "type" attribute, the type of the symbol.
2341 ** The "gdb.breakpoint" function has been deprecated in favor of
2344 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2345 of a function. This class is based on the "finish" command
2346 available in the CLI.
2348 ** Type objects for struct and union types now allow access to
2349 the fields using standard Python dictionary (mapping) methods.
2350 For example, "some_type['myfield']" now works, as does
2351 "some_type.items()".
2353 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2356 ** A new function, "deep_items" has been added to the gdb.types
2357 module in the GDB Python modules library. This function returns
2358 an iterator over the fields of a struct or union type. Unlike
2359 the standard Python "iteritems" method, it will recursively traverse
2360 any anonymous fields.
2364 ** "*stopped" events can report several new "reason"s, such as
2367 ** Breakpoint changes are now notified using new async records, like
2368 "=breakpoint-modified".
2370 ** New command -ada-task-info.
2372 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2373 $sdir specifies the default system locations of shared libraries.
2374 $pdir specifies the directory where the libpthread used by the application
2377 GDB no longer looks in $sdir and $pdir after it has searched the directories
2378 mentioned in libthread-db-search-path. If you want to search those
2379 directories, they must be specified in libthread-db-search-path.
2380 The default value of libthread-db-search-path on GNU/Linux and Solaris
2381 systems is now "$sdir:$pdir".
2383 $pdir is not supported by gdbserver, it is currently ignored.
2384 $sdir is supported by gdbserver.
2386 * New configure option --with-iconv-bin.
2387 When using the internationalization support like the one in the GNU C
2388 library, GDB will invoke the "iconv" program to get a list of supported
2389 character sets. If this program lives in a non-standard location, one can
2390 use this option to specify where to find it.
2392 * When natively debugging programs on PowerPC BookE processors running
2393 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2394 watchpoints, which specify a mask in addition to an address to watch.
2395 The mask specifies that some bits of an address (the bits which are
2396 reset in the mask) should be ignored when matching the address accessed
2397 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2398 section in the user manual for more details.
2400 * The new option --once causes GDBserver to stop listening for connections once
2401 the first connection is made. The listening port used by GDBserver will
2402 become available after that.
2404 * New commands "info macros" and "alias" have been added.
2406 * New function parameters suffix @entry specifies value of function parameter
2407 at the time the function got called. Entry values are available only since
2413 "!" is now an alias of the "shell" command.
2414 Note that no space is needed between "!" and SHELL COMMAND.
2418 watch EXPRESSION mask MASK_VALUE
2419 The watch command now supports the mask argument which allows creation
2420 of masked watchpoints, if the current architecture supports this feature.
2422 info auto-load-scripts [REGEXP]
2423 This command was formerly named "maintenance print section-scripts".
2424 It is now generally useful and is no longer a maintenance-only command.
2426 info macro [-all] [--] MACRO
2427 The info macro command has new options `-all' and `--'. The first for
2428 printing all definitions of a macro. The second for explicitly specifying
2429 the end of arguments and the beginning of the macro name in case the macro
2430 name starts with a hyphen.
2432 collect[/s] EXPRESSIONS
2433 The tracepoint collect command now takes an optional modifier "/s"
2434 that directs it to dereference pointer-to-character types and
2435 collect the bytes of memory up to a zero byte. The behavior is
2436 similar to what you see when you use the regular print command on a
2437 string. An optional integer following the "/s" sets a bound on the
2438 number of bytes that will be collected.
2441 The trace start command now interprets any supplied arguments as a
2442 note to be recorded with the trace run, with an effect similar to
2443 setting the variable trace-notes.
2446 The trace stop command now interprets any arguments as a note to be
2447 mentioned along with the tstatus report that the trace was stopped
2448 with a command. The effect is similar to setting the variable
2451 * Tracepoints can now be enabled and disabled at any time after a trace
2452 experiment has been started using the standard "enable" and "disable"
2453 commands. It is now possible to start a trace experiment with no enabled
2454 tracepoints; GDB will display a warning, but will allow the experiment to
2455 begin, assuming that tracepoints will be enabled as needed while the trace
2458 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2459 locations with 4-byte instructions, when they were previously
2460 limited to locations with instructions of 5 bytes or longer.
2464 set debug dwarf2-read
2465 show debug dwarf2-read
2466 Turns on or off display of debugging messages related to reading
2467 DWARF debug info. The default is off.
2469 set debug symtab-create
2470 show debug symtab-create
2471 Turns on or off display of debugging messages related to symbol table
2472 creation. The default is off.
2475 show extended-prompt
2476 Set the GDB prompt, and allow escape sequences to be inserted to
2477 display miscellaneous information (see 'help set extended-prompt'
2478 for the list of sequences). This prompt (and any information
2479 accessed through the escape sequences) is updated every time the
2480 prompt is displayed.
2482 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2483 show print entry-values
2484 Set printing of frame argument values at function entry. In some cases
2485 GDB can determine the value of function argument which was passed by the
2486 function caller, even if the value was modified inside the called function.
2488 set debug entry-values
2489 show debug entry-values
2490 Control display of debugging info for determining frame argument values at
2491 function entry and virtual tail call frames.
2493 set basenames-may-differ
2494 show basenames-may-differ
2495 Set whether a source file may have multiple base names.
2496 (A "base name" is the name of a file with the directory part removed.
2497 Example: The base name of "/home/user/hello.c" is "hello.c".)
2498 If set, GDB will canonicalize file names (e.g., expand symlinks)
2499 before comparing them. Canonicalization is an expensive operation,
2500 but it allows the same file be known by more than one base name.
2501 If not set (the default), all source files are assumed to have just
2502 one base name, and gdb will do file name comparisons more efficiently.
2508 Set a user name and notes for the current and any future trace runs.
2509 This is useful for long-running and/or disconnected traces, to
2510 inform others (or yourself) as to who is running the trace, supply
2511 contact information, or otherwise explain what is going on.
2513 set trace-stop-notes
2514 show trace-stop-notes
2515 Set a note attached to the trace run, that is displayed when the
2516 trace has been stopped by a tstop command. This is useful for
2517 instance as an explanation, if you are stopping a trace run that was
2518 started by someone else.
2520 * New remote packets
2524 Dynamically enable a tracepoint in a started trace experiment.
2528 Dynamically disable a tracepoint in a started trace experiment.
2532 Set the user and notes of the trace run.
2536 Query the current status of a tracepoint.
2540 Query the minimum length of instruction at which a fast tracepoint may
2543 * Dcache size (number of lines) and line-size are now runtime-configurable
2544 via "set dcache line" and "set dcache line-size" commands.
2548 Texas Instruments TMS320C6x tic6x-*-*
2552 Renesas RL78 rl78-*-elf
2554 *** Changes in GDB 7.3.1
2556 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2558 *** Changes in GDB 7.3
2560 * GDB has a new command: "thread find [REGEXP]".
2561 It finds the thread id whose name, target id, or thread extra info
2562 matches the given regular expression.
2564 * The "catch syscall" command now works on mips*-linux* targets.
2566 * The -data-disassemble MI command now supports modes 2 and 3 for
2567 dumping the instruction opcodes.
2569 * New command line options
2571 -data-directory DIR Specify DIR as the "data-directory".
2572 This is mostly for testing purposes.
2574 * The "maint set python auto-load on|off" command has been renamed to
2575 "set auto-load-scripts on|off".
2577 * GDB has a new command: "set directories".
2578 It is like the "dir" command except that it replaces the
2579 source path list instead of augmenting it.
2581 * GDB now understands thread names.
2583 On GNU/Linux, "info threads" will display the thread name as set by
2584 prctl or pthread_setname_np.
2586 There is also a new command, "thread name", which can be used to
2587 assign a name internally for GDB to display.
2590 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2591 has been integrated into GDB.
2595 ** The function gdb.Write now accepts an optional keyword 'stream'.
2596 This keyword, when provided, will direct the output to either
2597 stdout, stderr, or GDB's logging output.
2599 ** Parameters can now be be sub-classed in Python, and in particular
2600 you may implement the get_set_doc and get_show_doc functions.
2601 This improves how Parameter set/show documentation is processed
2602 and allows for more dynamic content.
2604 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2605 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2606 have an is_valid method.
2608 ** Breakpoints can now be sub-classed in Python, and in particular
2609 you may implement a 'stop' function that is executed each time
2610 the inferior reaches that breakpoint.
2612 ** New function gdb.lookup_global_symbol looks up a global symbol.
2614 ** GDB values in Python are now callable if the value represents a
2615 function. For example, if 'some_value' represents a function that
2616 takes two integer parameters and returns a value, you can call
2617 that function like so:
2619 result = some_value (10,20)
2621 ** Module gdb.types has been added.
2622 It contains a collection of utilities for working with gdb.Types objects:
2623 get_basic_type, has_field, make_enum_dict.
2625 ** Module gdb.printing has been added.
2626 It contains utilities for writing and registering pretty-printers.
2627 New classes: PrettyPrinter, SubPrettyPrinter,
2628 RegexpCollectionPrettyPrinter.
2629 New function: register_pretty_printer.
2631 ** New commands "info pretty-printers", "enable pretty-printer" and
2632 "disable pretty-printer" have been added.
2634 ** gdb.parameter("directories") is now available.
2636 ** New function gdb.newest_frame returns the newest frame in the
2639 ** The gdb.InferiorThread class has a new "name" attribute. This
2640 holds the thread's name.
2642 ** Python Support for Inferior events.
2643 Python scripts can add observers to be notified of events
2644 occurring in the process being debugged.
2645 The following events are currently supported:
2646 - gdb.events.cont Continue event.
2647 - gdb.events.exited Inferior exited event.
2648 - gdb.events.stop Signal received, and Breakpoint hit events.
2652 ** GDB now puts template parameters in scope when debugging in an
2653 instantiation. For example, if you have:
2655 template<int X> int func (void) { return X; }
2657 then if you step into func<5>, "print X" will show "5". This
2658 feature requires proper debuginfo support from the compiler; it
2659 was added to GCC 4.5.
2661 ** The motion commands "next", "finish", "until", and "advance" now
2662 work better when exceptions are thrown. In particular, GDB will
2663 no longer lose control of the inferior; instead, the GDB will
2664 stop the inferior at the point at which the exception is caught.
2665 This functionality requires a change in the exception handling
2666 code that was introduced in GCC 4.5.
2668 * GDB now follows GCC's rules on accessing volatile objects when
2669 reading or writing target state during expression evaluation.
2670 One notable difference to prior behavior is that "print x = 0"
2671 no longer generates a read of x; the value of the assignment is
2672 now always taken directly from the value being assigned.
2674 * GDB now has some support for using labels in the program's source in
2675 linespecs. For instance, you can use "advance label" to continue
2676 execution to a label.
2678 * GDB now has support for reading and writing a new .gdb_index
2679 section. This section holds a fast index of DWARF debugging
2680 information and can be used to greatly speed up GDB startup and
2681 operation. See the documentation for `save gdb-index' for details.
2683 * The "watch" command now accepts an optional "-location" argument.
2684 When used, this causes GDB to watch the memory referred to by the
2685 expression. Such a watchpoint is never deleted due to it going out
2688 * GDB now supports thread debugging of core dumps on GNU/Linux.
2690 GDB now activates thread debugging using the libthread_db library
2691 when debugging GNU/Linux core dumps, similarly to when debugging
2692 live processes. As a result, when debugging a core dump file, GDB
2693 is now able to display pthread_t ids of threads. For example, "info
2694 threads" shows the same output as when debugging the process when it
2695 was live. In earlier releases, you'd see something like this:
2698 * 1 LWP 6780 main () at main.c:10
2700 While now you see this:
2703 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2705 It is also now possible to inspect TLS variables when debugging core
2708 When debugging a core dump generated on a machine other than the one
2709 used to run GDB, you may need to point GDB at the correct
2710 libthread_db library with the "set libthread-db-search-path"
2711 command. See the user manual for more details on this command.
2713 * When natively debugging programs on PowerPC BookE processors running
2714 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2715 which stop execution of the inferior whenever it executes an instruction
2716 at any address within the specified range. See the "PowerPC Embedded"
2717 section in the user manual for more details.
2719 * New features in the GDB remote stub, GDBserver
2721 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2722 and i686 LynxOS (version 5.x).
2724 ** GDBserver is now supported on Blackfin Linux.
2726 * New native configurations
2728 ia64 HP-UX ia64-*-hpux*
2732 Analog Devices, Inc. Blackfin Processor bfin-*
2734 * Ada task switching is now supported on sparc-elf targets when
2735 debugging a program using the Ravenscar Profile. For more information,
2736 see the "Tasking Support when using the Ravenscar Profile" section
2737 in the GDB user manual.
2739 * Guile support was removed.
2741 * New features in the GNU simulator
2743 ** The --map-info flag lists all known core mappings.
2745 ** CFI flashes may be simulated via the "cfi" device.
2747 *** Changes in GDB 7.2
2749 * Shared library support for remote targets by default
2751 When GDB is configured for a generic, non-OS specific target, like
2752 for example, --target=arm-eabi or one of the many *-*-elf targets,
2753 GDB now queries remote stubs for loaded shared libraries using the
2754 `qXfer:libraries:read' packet. Previously, shared library support
2755 was always disabled for such configurations.
2759 ** Argument Dependent Lookup (ADL)
2761 In C++ ADL lookup directs function search to the namespaces of its
2762 arguments even if the namespace has not been imported.
2772 Here the compiler will search for `foo' in the namespace of 'b'
2773 and find A::foo. GDB now supports this. This construct is commonly
2774 used in the Standard Template Library for operators.
2776 ** Improved User Defined Operator Support
2778 In addition to member operators, GDB now supports lookup of operators
2779 defined in a namespace and imported with a `using' directive, operators
2780 defined in the global scope, operators imported implicitly from an
2781 anonymous namespace, and the ADL operators mentioned in the previous
2783 GDB now also supports proper overload resolution for all the previously
2784 mentioned flavors of operators.
2786 ** static const class members
2788 Printing of static const class members that are initialized in the
2789 class definition has been fixed.
2791 * Windows Thread Information Block access.
2793 On Windows targets, GDB now supports displaying the Windows Thread
2794 Information Block (TIB) structure. This structure is visible either
2795 by using the new command `info w32 thread-information-block' or, by
2796 dereferencing the new convenience variable named `$_tlb', a
2797 thread-specific pointer to the TIB. This feature is also supported
2798 when remote debugging using GDBserver.
2800 * Static tracepoints
2802 Static tracepoints are calls in the user program into a tracing
2803 library. One such library is a port of the LTTng kernel tracer to
2804 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2805 When debugging with GDBserver, GDB now supports combining the GDB
2806 tracepoint machinery with such libraries. For example: the user can
2807 use GDB to probe a static tracepoint marker (a call from the user
2808 program into the tracing library) with the new "strace" command (see
2809 "New commands" below). This creates a "static tracepoint" in the
2810 breakpoint list, that can be manipulated with the same feature set
2811 as fast and regular tracepoints. E.g., collect registers, local and
2812 global variables, collect trace state variables, and define
2813 tracepoint conditions. In addition, the user can collect extra
2814 static tracepoint marker specific data, by collecting the new
2815 $_sdata internal variable. When analyzing the trace buffer, you can
2816 inspect $_sdata like any other variable available to GDB. For more
2817 information, see the "Tracepoints" chapter in GDB user manual. New
2818 remote packets have been defined to support static tracepoints, see
2819 the "New remote packets" section below.
2821 * Better reconstruction of tracepoints after disconnected tracing
2823 GDB will attempt to download the original source form of tracepoint
2824 definitions when starting a trace run, and then will upload these
2825 upon reconnection to the target, resulting in a more accurate
2826 reconstruction of the tracepoints that are in use on the target.
2830 You can now exercise direct control over the ways that GDB can
2831 affect your program. For instance, you can disallow the setting of
2832 breakpoints, so that the program can run continuously (assuming
2833 non-stop mode). In addition, the "observer" variable is available
2834 to switch all of the different controls; in observer mode, GDB
2835 cannot affect the target's behavior at all, which is useful for
2836 tasks like diagnosing live systems in the field.
2838 * The new convenience variable $_thread holds the number of the
2841 * New remote packets
2845 Return the address of the Windows Thread Information Block of a given thread.
2849 In response to several of the tracepoint packets, the target may now
2850 also respond with a number of intermediate `qRelocInsn' request
2851 packets before the final result packet, to have GDB handle
2852 relocating an instruction to execute at a different address. This
2853 is particularly useful for stubs that support fast tracepoints. GDB
2854 reports support for this feature in the qSupported packet.
2858 List static tracepoint markers in the target program.
2862 List static tracepoint markers at a given address in the target
2865 qXfer:statictrace:read
2867 Read the static trace data collected (by a `collect $_sdata'
2868 tracepoint action). The remote stub reports support for this packet
2869 to gdb's qSupported query.
2873 Send the current settings of GDB's permission flags.
2877 Send part of the source (textual) form of a tracepoint definition,
2878 which includes location, conditional, and action list.
2880 * The source command now accepts a -s option to force searching for the
2881 script in the source search path even if the script name specifies
2884 * New features in the GDB remote stub, GDBserver
2886 - GDBserver now support tracepoints (including fast tracepoints, and
2887 static tracepoints). The feature is currently supported by the
2888 i386-linux and amd64-linux builds. See the "Tracepoints support
2889 in gdbserver" section in the manual for more information.
2891 GDBserver JIT compiles the tracepoint's conditional agent
2892 expression bytecode into native code whenever possible for low
2893 overhead dynamic tracepoints conditionals. For such tracepoints,
2894 an expression that examines program state is evaluated when the
2895 tracepoint is reached, in order to determine whether to capture
2896 trace data. If the condition is simple and false, processing the
2897 tracepoint finishes very quickly and no data is gathered.
2899 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2900 for static tracepoints support.
2902 - GDBserver now supports x86_64 Windows 64-bit debugging.
2904 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2905 it understands register description.
2907 * The --batch flag now disables pagination and queries.
2909 * X86 general purpose registers
2911 GDB now supports reading/writing byte, word and double-word x86
2912 general purpose registers directly. This means you can use, say,
2913 $ah or $ax to refer, respectively, to the byte register AH and
2914 16-bit word register AX that are actually portions of the 32-bit
2915 register EAX or 64-bit register RAX.
2917 * The `commands' command now accepts a range of breakpoints to modify.
2918 A plain `commands' following a command that creates multiple
2919 breakpoints affects all the breakpoints set by that command. This
2920 applies to breakpoints set by `rbreak', and also applies when a
2921 single `break' command creates multiple breakpoints (e.g.,
2922 breakpoints on overloaded c++ functions).
2924 * The `rbreak' command now accepts a filename specification as part of
2925 its argument, limiting the functions selected by the regex to those
2926 in the specified file.
2928 * Support for remote debugging Windows and SymbianOS shared libraries
2929 from Unix hosts has been improved. Non Windows GDB builds now can
2930 understand target reported file names that follow MS-DOS based file
2931 system semantics, such as file names that include drive letters and
2932 use the backslash character as directory separator. This makes it
2933 possible to transparently use the "set sysroot" and "set
2934 solib-search-path" on Unix hosts to point as host copies of the
2935 target's shared libraries. See the new command "set
2936 target-file-system-kind" described below, and the "Commands to
2937 specify files" section in the user manual for more information.
2941 eval template, expressions...
2942 Convert the values of one or more expressions under the control
2943 of the string template to a command line, and call it.
2945 set target-file-system-kind unix|dos-based|auto
2946 show target-file-system-kind
2947 Set or show the assumed file system kind for target reported file
2950 save breakpoints <filename>
2951 Save all current breakpoint definitions to a file suitable for use
2952 in a later debugging session. To read the saved breakpoint
2953 definitions, use the `source' command.
2955 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2958 info static-tracepoint-markers
2959 Display information about static tracepoint markers in the target.
2961 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2962 Define a static tracepoint by probing a marker at the given
2963 function, line, address, or marker ID.
2967 Enable and disable observer mode.
2969 set may-write-registers on|off
2970 set may-write-memory on|off
2971 set may-insert-breakpoints on|off
2972 set may-insert-tracepoints on|off
2973 set may-insert-fast-tracepoints on|off
2974 set may-interrupt on|off
2975 Set individual permissions for GDB effects on the target. Note that
2976 some of these settings can have undesirable or surprising
2977 consequences, particularly when changed in the middle of a session.
2978 For instance, disabling the writing of memory can prevent
2979 breakpoints from being inserted, cause single-stepping to fail, or
2980 even crash your program, if you disable after breakpoints have been
2981 inserted. However, GDB should not crash.
2983 set record memory-query on|off
2984 show record memory-query
2985 Control whether to stop the inferior if memory changes caused
2986 by an instruction cannot be recorded.
2991 The disassemble command now supports "start,+length" form of two arguments.
2995 ** GDB now provides a new directory location, called the python directory,
2996 where Python scripts written for GDB can be installed. The location
2997 of that directory is <data-directory>/python, where <data-directory>
2998 is the GDB data directory. For more details, see section `Scripting
2999 GDB using Python' in the manual.
3001 ** The GDB Python API now has access to breakpoints, symbols, symbol
3002 tables, program spaces, inferiors, threads and frame's code blocks.
3003 Additionally, GDB Parameters can now be created from the API, and
3004 manipulated via set/show in the CLI.
3006 ** New functions gdb.target_charset, gdb.target_wide_charset,
3007 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3009 ** New exception gdb.GdbError.
3011 ** Pretty-printers are now also looked up in the current program space.
3013 ** Pretty-printers can now be individually enabled and disabled.
3015 ** GDB now looks for names of Python scripts to auto-load in a
3016 special section named `.debug_gdb_scripts', in addition to looking
3017 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3019 * Tracepoint actions were unified with breakpoint commands. In particular,
3020 there are no longer differences in "info break" output for breakpoints and
3021 tracepoints and the "commands" command can be used for both tracepoints and
3022 regular breakpoints.
3026 ARM Symbian arm*-*-symbianelf*
3028 * D language support.
3029 GDB now supports debugging programs written in the D programming
3032 * GDB now supports the extended ptrace interface for PowerPC which is
3033 available since Linux kernel version 2.6.34. This automatically enables
3034 any hardware breakpoints and additional hardware watchpoints available in
3035 the processor. The old ptrace interface exposes just one hardware
3036 watchpoint and no hardware breakpoints.
3038 * GDB is now able to use the Data Value Compare (DVC) register available on
3039 embedded PowerPC processors to implement in hardware simple watchpoint
3040 conditions of the form:
3042 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3044 This works in native GDB running on Linux kernels with the extended ptrace
3045 interface mentioned above.
3047 *** Changes in GDB 7.1
3051 ** Namespace Support
3053 GDB now supports importing of namespaces in C++. This enables the
3054 user to inspect variables from imported namespaces. Support for
3055 namepace aliasing has also been added. So, if a namespace is
3056 aliased in the current scope (e.g. namepace C=A; ) the user can
3057 print variables using the alias (e.g. (gdb) print C::x).
3061 All known bugs relating to the printing of virtual base class were
3062 fixed. It is now possible to call overloaded static methods using a
3067 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3068 and reinterpret_cast<> are now handled by the C++ expression parser.
3072 Xilinx MicroBlaze microblaze-*-*
3077 Xilinx MicroBlaze microblaze
3080 * Multi-program debugging.
3082 GDB now has support for multi-program (a.k.a. multi-executable or
3083 multi-exec) debugging. This allows for debugging multiple inferiors
3084 simultaneously each running a different program under the same GDB
3085 session. See "Debugging Multiple Inferiors and Programs" in the
3086 manual for more information. This implied some user visible changes
3087 in the multi-inferior support. For example, "info inferiors" now
3088 lists inferiors that are not running yet or that have exited
3089 already. See also "New commands" and "New options" below.
3091 * New tracing features
3093 GDB's tracepoint facility now includes several new features:
3095 ** Trace state variables
3097 GDB tracepoints now include support for trace state variables, which
3098 are variables managed by the target agent during a tracing
3099 experiment. They are useful for tracepoints that trigger each
3100 other, so for instance one tracepoint can count hits in a variable,
3101 and then a second tracepoint has a condition that is true when the
3102 count reaches a particular value. Trace state variables share the
3103 $-syntax of GDB convenience variables, and can appear in both
3104 tracepoint actions and condition expressions. Use the "tvariable"
3105 command to create, and "info tvariables" to view; see "Trace State
3106 Variables" in the manual for more detail.
3110 GDB now includes an option for defining fast tracepoints, which
3111 targets may implement more efficiently, such as by installing a jump
3112 into the target agent rather than a trap instruction. The resulting
3113 speedup can be by two orders of magnitude or more, although the
3114 tradeoff is that some program locations on some target architectures
3115 might not allow fast tracepoint installation, for instance if the
3116 instruction to be replaced is shorter than the jump. To request a
3117 fast tracepoint, use the "ftrace" command, with syntax identical to
3118 the regular trace command.
3120 ** Disconnected tracing
3122 It is now possible to detach GDB from the target while it is running
3123 a trace experiment, then reconnect later to see how the experiment
3124 is going. In addition, a new variable disconnected-tracing lets you
3125 tell the target agent whether to continue running a trace if the
3126 connection is lost unexpectedly.
3130 GDB now has the ability to save the trace buffer into a file, and
3131 then use that file as a target, similarly to you can do with
3132 corefiles. You can select trace frames, print data that was
3133 collected in them, and use tstatus to display the state of the
3134 tracing run at the moment that it was saved. To create a trace
3135 file, use "tsave <filename>", and to use it, do "target tfile
3138 ** Circular trace buffer
3140 You can ask the target agent to handle the trace buffer as a
3141 circular buffer, discarding the oldest trace frames to make room for
3142 newer ones, by setting circular-trace-buffer to on. This feature may
3143 not be available for all target agents.
3148 The disassemble command, when invoked with two arguments, now requires
3149 the arguments to be comma-separated.
3152 The info variables command now displays variable definitions. Files
3153 which only declare a variable are not shown.
3156 The source command is now capable of sourcing Python scripts.
3157 This feature is dependent on the debugger being build with Python
3160 Related to this enhancement is also the introduction of a new command
3161 "set script-extension" (see below).
3163 * New commands (for set/show, see "New options" below)
3165 record save [<FILENAME>]
3166 Save a file (in core file format) containing the process record
3167 execution log for replay debugging at a later time.
3169 record restore <FILENAME>
3170 Restore the process record execution log that was saved at an
3171 earlier time, for replay debugging.
3173 add-inferior [-copies <N>] [-exec <FILENAME>]
3176 clone-inferior [-copies <N>] [ID]
3177 Make a new inferior ready to execute the same program another
3178 inferior has loaded.
3183 maint info program-spaces
3184 List the program spaces loaded into GDB.
3186 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3187 show remote interrupt-sequence
3188 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3189 as the sequence to the remote target in order to interrupt the execution.
3190 Ctrl-C is a default. Some system prefers BREAK which is high level of
3191 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3192 Magic SysRq g. It is BREAK signal and character 'g'.
3194 set remote interrupt-on-connect [on | off]
3195 show remote interrupt-on-connect
3196 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3197 remote target when gdb connects to it. This is needed when you debug
3200 set remotebreak [on | off]
3202 Deprecated. Use "set/show remote interrupt-sequence" instead.
3204 tvariable $NAME [ = EXP ]
3205 Create or modify a trace state variable.
3208 List trace state variables and their values.
3210 delete tvariable $NAME ...
3211 Delete one or more trace state variables.
3214 Evaluate the given expressions without collecting anything into the
3215 trace buffer. (Valid in tracepoint actions only.)
3217 ftrace FN / FILE:LINE / *ADDR
3218 Define a fast tracepoint at the given function, line, or address.
3220 * New expression syntax
3222 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3223 GDB now parses 0b101010 identically with 42.
3227 set follow-exec-mode new|same
3228 show follow-exec-mode
3229 Control whether GDB reuses the same inferior across an exec call or
3230 creates a new one. This is useful to be able to restart the old
3231 executable after the inferior having done an exec call.
3233 set default-collect EXPR, ...
3234 show default-collect
3235 Define a list of expressions to be collected at each tracepoint.
3236 This is a useful way to ensure essential items are not overlooked,
3237 such as registers or a critical global variable.
3239 set disconnected-tracing
3240 show disconnected-tracing
3241 If set to 1, the target is instructed to continue tracing if it
3242 loses its connection to GDB. If 0, the target is to stop tracing
3245 set circular-trace-buffer
3246 show circular-trace-buffer
3247 If set to on, the target is instructed to use a circular trace buffer
3248 and discard the oldest trace frames instead of stopping the trace due
3249 to a full trace buffer. If set to off, the trace stops when the buffer
3250 fills up. Some targets may not support this.
3252 set script-extension off|soft|strict
3253 show script-extension
3254 If set to "off", the debugger does not perform any script language
3255 recognition, and all sourced files are assumed to be GDB scripts.
3256 If set to "soft" (the default), files are sourced according to
3257 filename extension, falling back to GDB scripts if the first
3259 If set to "strict", files are sourced according to filename extension.
3261 set ada trust-PAD-over-XVS on|off
3262 show ada trust-PAD-over-XVS
3263 If off, activate a workaround against a bug in the debugging information
3264 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3265 the GCC sources for more information about the GNAT encoding and
3266 PAD types in particular). It is always safe to set this option to
3267 off, but this introduces a slight performance penalty. The default
3270 * Python API Improvements
3272 ** GDB provides the new class gdb.LazyString. This is useful in
3273 some pretty-printing cases. The new method gdb.Value.lazy_string
3274 provides a simple way to create objects of this type.
3276 ** The fields returned by gdb.Type.fields now have an
3277 `is_base_class' attribute.
3279 ** The new method gdb.Type.range returns the range of an array type.
3281 ** The new method gdb.parse_and_eval can be used to parse and
3282 evaluate an expression.
3284 * New remote packets
3287 Define a trace state variable.
3290 Get the current value of a trace state variable.
3293 Set desired tracing behavior upon disconnection.
3296 Set the trace buffer to be linear or circular.
3299 Get data about the tracepoints currently in use.
3303 Process record now works correctly with hardware watchpoints.
3305 Multiple bug fixes have been made to the mips-irix port, making it
3306 much more reliable. In particular:
3307 - Debugging threaded applications is now possible again. Previously,
3308 GDB would hang while starting the program, or while waiting for
3309 the program to stop at a breakpoint.
3310 - Attaching to a running process no longer hangs.
3311 - An error occurring while loading a core file has been fixed.
3312 - Changing the value of the PC register now works again. This fixes
3313 problems observed when using the "jump" command, or when calling
3314 a function from GDB, or even when assigning a new value to $pc.
3315 - With the "finish" and "return" commands, the return value for functions
3316 returning a small array is now correctly printed.
3317 - It is now possible to break on shared library code which gets executed
3318 during a shared library init phase (code executed while executing
3319 their .init section). Previously, the breakpoint would have no effect.
3320 - GDB is now able to backtrace through the signal handler for
3321 non-threaded programs.
3323 PIE (Position Independent Executable) programs debugging is now supported.
3324 This includes debugging execution of PIC (Position Independent Code) shared
3325 libraries although for that, it should be possible to run such libraries as an
3328 *** Changes in GDB 7.0
3330 * GDB now has an interface for JIT compilation. Applications that
3331 dynamically generate code can create symbol files in memory and register
3332 them with GDB. For users, the feature should work transparently, and
3333 for JIT developers, the interface is documented in the GDB manual in the
3334 "JIT Compilation Interface" chapter.
3336 * Tracepoints may now be conditional. The syntax is as for
3337 breakpoints; either an "if" clause appended to the "trace" command,
3338 or the "condition" command is available. GDB sends the condition to
3339 the target for evaluation using the same bytecode format as is used
3340 for tracepoint actions.
3342 * The disassemble command now supports: an optional /r modifier, print the
3343 raw instructions in hex as well as in symbolic form, and an optional /m
3344 modifier to print mixed source+assembly.
3346 * Process record and replay
3348 In a architecture environment that supports ``process record and
3349 replay'', ``process record and replay'' target can record a log of
3350 the process execution, and replay it with both forward and reverse
3353 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3354 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3355 set execution-direction {forward|reverse}, for targets that support
3358 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3359 feature is available with a native GDB running on kernel version
3362 * GDB now has support for multi-byte and wide character sets on the
3363 target. Strings whose character type is wchar_t, char16_t, or
3364 char32_t are now correctly printed. GDB supports wide- and unicode-
3365 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3366 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3367 `printf'. This feature requires iconv to work properly; if your
3368 system does not have a working iconv, GDB can use GNU libiconv. See
3369 the installation instructions for more information.
3371 * GDB now supports automatic retrieval of shared library files from
3372 remote targets. To use this feature, specify a system root that begins
3373 with the `remote:' prefix, either via the `set sysroot' command or via
3374 the `--with-sysroot' configure-time option.
3376 * "info sharedlibrary" now takes an optional regex of libraries to show,
3377 and it now reports if a shared library has no debugging information.
3379 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3380 now complete on file names.
3382 * When completing in expressions, gdb will attempt to limit
3383 completions to allowable structure or union fields, where appropriate.
3384 For instance, consider:
3386 # struct example { int f1; double f2; };
3387 # struct example variable;
3390 If the user types TAB at the end of this command line, the available
3391 completions will be "f1" and "f2".
3393 * Inlined functions are now supported. They show up in backtraces, and
3394 the "step", "next", and "finish" commands handle them automatically.
3396 * GDB now supports the token-splicing (##) and stringification (#)
3397 operators when expanding macros. It also supports variable-arity
3400 * GDB now supports inspecting extra signal information, exported by
3401 the new $_siginfo convenience variable. The feature is currently
3402 implemented on linux ARM, i386 and amd64.
3404 * GDB can now display the VFP floating point registers and NEON vector
3405 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3406 can provide these registers (requires Linux 2.6.30 or later). Remote
3407 and simulator targets may also provide them.
3409 * New remote packets
3412 Search memory for a sequence of bytes.
3415 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3416 operation over reliable transport links. Use of this packet is
3417 controlled by the `set remote noack-packet' command.
3420 Kill the process with the specified process ID. Use this in preference
3421 to `k' when multiprocess protocol extensions are supported.
3424 Obtains additional operating system information
3428 Read or write additional signal information.
3430 * Removed remote protocol undocumented extension
3432 An undocumented extension to the remote protocol's `S' stop reply
3433 packet that permited the stub to pass a process id was removed.
3434 Remote servers should use the `T' stop reply packet instead.
3436 * GDB now supports multiple function calling conventions according to the
3437 DWARF-2 DW_AT_calling_convention function attribute.
3439 * The SH target utilizes the aforementioned change to distinguish between gcc
3440 and Renesas calling convention. It also adds the new CLI commands
3441 `set/show sh calling-convention'.
3443 * GDB can now read compressed debug sections, as produced by GNU gold
3444 with the --compress-debug-sections=zlib flag.
3446 * 64-bit core files are now supported on AIX.
3448 * Thread switching is now supported on Tru64.
3450 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3451 which will be allocated using malloc later in program execution.
3453 * The qXfer:libraries:read remote procotol packet now allows passing a
3454 list of section offsets.
3456 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3457 conditions handling signals delivered during attach or thread creation
3458 have also been fixed.
3460 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3461 From the user's standpoint, all unqualified instances of True and False
3462 are treated as the standard definitions, regardless of context.
3464 * GDB now parses C++ symbol and type names more flexibly. For
3467 template<typename T> class C { };
3470 GDB will now correctly handle all of:
3472 ptype C<char const *>
3473 ptype C<char const*>
3474 ptype C<const char *>
3475 ptype C<const char*>
3477 * New features in the GDB remote stub, gdbserver
3479 - The "--wrapper" command-line argument tells gdbserver to use a
3480 wrapper program to launch programs for debugging.
3482 - On PowerPC and S/390 targets, it is now possible to use a single
3483 gdbserver executable to debug both 32-bit and 64-bit programs.
3484 (This requires gdbserver itself to be built as a 64-bit executable.)
3486 - gdbserver uses the new noack protocol mode for TCP connections to
3487 reduce communications latency, if also supported and enabled in GDB.
3489 - Support for the sparc64-linux-gnu target is now included in
3492 - The amd64-linux build of gdbserver now supports debugging both
3493 32-bit and 64-bit programs.
3495 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3496 now support hardware watchpoints, and will use them automatically
3501 GDB now has support for scripting using Python. Whether this is
3502 available is determined at configure time.
3504 New GDB commands can now be written in Python.
3506 * Ada tasking support
3508 Ada tasks can now be inspected in GDB. The following commands have
3512 Print the list of Ada tasks.
3514 Print detailed information about task number N.
3516 Print the task number of the current task.
3518 Switch the context of debugging to task number N.
3520 * Support for user-defined prefixed commands. The "define" command can
3521 add new commands to existing prefixes, e.g. "target".
3523 * Multi-inferior, multi-process debugging.
3525 GDB now has generalized support for multi-inferior debugging. See
3526 "Debugging Multiple Inferiors" in the manual for more information.
3527 Although availability still depends on target support, the command
3528 set is more uniform now. The GNU/Linux specific multi-forks support
3529 has been migrated to this new framework. This implied some user
3530 visible changes; see "New commands" and also "Removed commands"
3533 * Target descriptions can now describe the target OS ABI. See the
3534 "Target Description Format" section in the user manual for more
3537 * Target descriptions can now describe "compatible" architectures
3538 to indicate that the target can execute applications for a different
3539 architecture in addition to those for the main target architecture.
3540 See the "Target Description Format" section in the user manual for
3543 * Multi-architecture debugging.
3545 GDB now includes general supports for debugging applications on
3546 hybrid systems that use more than one single processor architecture
3547 at the same time. Each such hybrid architecture still requires
3548 specific support to be added. The only hybrid architecture supported
3549 in this version of GDB is the Cell Broadband Engine.
3551 * GDB now supports integrated debugging of Cell/B.E. applications that
3552 use both the PPU and SPU architectures. To enable support for hybrid
3553 Cell/B.E. debugging, you need to configure GDB to support both the
3554 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3555 --enable-targets configure option.
3557 * Non-stop mode debugging.
3559 For some targets, GDB now supports an optional mode of operation in
3560 which you can examine stopped threads while other threads continue
3561 to execute freely. This is referred to as non-stop mode, with the
3562 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3563 section in the user manual for more information.
3565 To be able to support remote non-stop debugging, a remote stub needs
3566 to implement the non-stop mode remote protocol extensions, as
3567 described in the "Remote Non-Stop" section of the user manual. The
3568 GDB remote stub, gdbserver, has been adjusted to support these
3569 extensions on linux targets.
3571 * New commands (for set/show, see "New options" below)
3573 catch syscall [NAME(S) | NUMBER(S)]
3574 Catch system calls. Arguments, which should be names of system
3575 calls or their numbers, mean catch only those syscalls. Without
3576 arguments, every syscall will be caught. When the inferior issues
3577 any of the specified syscalls, GDB will stop and announce the system
3578 call, both when it is called and when its call returns. This
3579 feature is currently available with a native GDB running on the
3580 Linux Kernel, under the following architectures: x86, x86_64,
3581 PowerPC and PowerPC64.
3583 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3585 Search memory for a sequence of bytes.
3587 maint set python print-stack
3588 maint show python print-stack
3589 Show a stack trace when an error is encountered in a Python script.
3592 Invoke CODE by passing it to the Python interpreter.
3597 These allow macros to be defined, undefined, and listed
3601 Show operating system information about processes.
3604 List the inferiors currently under GDB's control.
3607 Switch focus to inferior number NUM.
3610 Detach from inferior number NUM.
3613 Kill inferior number NUM.
3617 set spu stop-on-load
3618 show spu stop-on-load
3619 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3621 set spu auto-flush-cache
3622 show spu auto-flush-cache
3623 Control whether to automatically flush the software-managed cache
3624 during Cell/B.E. debugging.
3626 set sh calling-convention
3627 show sh calling-convention
3628 Control the calling convention used when calling SH target functions.
3631 show debug timestamp
3632 Control display of timestamps with GDB debugging output.
3634 set disassemble-next-line
3635 show disassemble-next-line
3636 Control display of disassembled source lines or instructions when
3639 set remote noack-packet
3640 show remote noack-packet
3641 Set/show the use of remote protocol QStartNoAckMode packet. See above
3642 under "New remote packets."
3644 set remote query-attached-packet
3645 show remote query-attached-packet
3646 Control use of remote protocol `qAttached' (query-attached) packet.
3648 set remote read-siginfo-object
3649 show remote read-siginfo-object
3650 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3653 set remote write-siginfo-object
3654 show remote write-siginfo-object
3655 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3658 set remote reverse-continue
3659 show remote reverse-continue
3660 Control use of remote protocol 'bc' (reverse-continue) packet.
3662 set remote reverse-step
3663 show remote reverse-step
3664 Control use of remote protocol 'bs' (reverse-step) packet.
3666 set displaced-stepping
3667 show displaced-stepping
3668 Control displaced stepping mode. Displaced stepping is a way to
3669 single-step over breakpoints without removing them from the debuggee.
3670 Also known as "out-of-line single-stepping".
3673 show debug displaced
3674 Control display of debugging info for displaced stepping.
3676 maint set internal-error
3677 maint show internal-error
3678 Control what GDB does when an internal error is detected.
3680 maint set internal-warning
3681 maint show internal-warning
3682 Control what GDB does when an internal warning is detected.
3687 Use a wrapper program to launch programs for debugging.
3689 set multiple-symbols (all|ask|cancel)
3690 show multiple-symbols
3691 The value of this variable can be changed to adjust the debugger behavior
3692 when an expression or a breakpoint location contains an ambiguous symbol
3693 name (an overloaded function name, for instance).
3695 set breakpoint always-inserted
3696 show breakpoint always-inserted
3697 Keep breakpoints always inserted in the target, as opposed to inserting
3698 them when resuming the target, and removing them when the target stops.
3699 This option can improve debugger performance on slow remote targets.
3701 set arm fallback-mode (arm|thumb|auto)
3702 show arm fallback-mode
3703 set arm force-mode (arm|thumb|auto)
3705 These commands control how ARM GDB determines whether instructions
3706 are ARM or Thumb. The default for both settings is auto, which uses
3707 the current CPSR value for instructions without symbols; previous
3708 versions of GDB behaved as if "set arm fallback-mode arm".
3710 set disable-randomization
3711 show disable-randomization
3712 Standalone programs run with the virtual address space randomization enabled
3713 by default on some platforms. This option keeps the addresses stable across
3714 multiple debugging sessions.
3718 Control whether other threads are stopped or not when some thread hits
3723 Requests that asynchronous execution is enabled in the target, if available.
3724 In this case, it's possible to resume target in the background, and interact
3725 with GDB while the target is running. "show target-async" displays the
3726 current state of asynchronous execution of the target.
3728 set target-wide-charset
3729 show target-wide-charset
3730 The target-wide-charset is the name of the character set that GDB
3731 uses when printing characters whose type is wchar_t.
3733 set tcp auto-retry (on|off)
3735 set tcp connect-timeout
3736 show tcp connect-timeout
3737 These commands allow GDB to retry failed TCP connections to a remote stub
3738 with a specified timeout period; this is useful if the stub is launched
3739 in parallel with GDB but may not be ready to accept connections immediately.
3741 set libthread-db-search-path
3742 show libthread-db-search-path
3743 Control list of directories which GDB will search for appropriate
3746 set schedule-multiple (on|off)
3747 show schedule-multiple
3748 Allow GDB to resume all threads of all processes or only threads of
3749 the current process.
3753 Use more aggressive caching for accesses to the stack. This improves
3754 performance of remote debugging (particularly backtraces) without
3755 affecting correctness.
3757 set interactive-mode (on|off|auto)
3758 show interactive-mode
3759 Control whether GDB runs in interactive mode (on) or not (off).
3760 When in interactive mode, GDB waits for the user to answer all
3761 queries. Otherwise, GDB does not wait and assumes the default
3762 answer. When set to auto (the default), GDB determines which
3763 mode to use based on the stdin settings.
3768 For program forks, this is replaced by the new more generic `info
3769 inferiors' command. To list checkpoints, you can still use the
3770 `info checkpoints' command, which was an alias for the `info forks'
3774 Replaced by the new `inferior' command. To switch between
3775 checkpoints, you can still use the `restart' command, which was an
3776 alias for the `fork' command.
3779 This is removed, since some targets don't have a notion of
3780 processes. To switch between processes, you can still use the
3781 `inferior' command using GDB's own inferior number.
3784 For program forks, this is replaced by the new more generic `kill
3785 inferior' command. To delete a checkpoint, you can still use the
3786 `delete checkpoint' command, which was an alias for the `delete
3790 For program forks, this is replaced by the new more generic `detach
3791 inferior' command. To detach a checkpoint, you can still use the
3792 `detach checkpoint' command, which was an alias for the `detach
3795 * New native configurations
3797 x86/x86_64 Darwin i[34567]86-*-darwin*
3799 x86_64 MinGW x86_64-*-mingw*
3803 Lattice Mico32 lm32-*
3804 x86 DICOS i[34567]86-*-dicos*
3805 x86_64 DICOS x86_64-*-dicos*
3808 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3809 (mingw32ce) debugging.
3815 These commands were actually not implemented on any target.
3817 *** Changes in GDB 6.8
3819 * New native configurations
3821 NetBSD/hppa hppa*-*netbsd*
3822 Xtensa GNU/Linux xtensa*-*-linux*
3826 NetBSD/hppa hppa*-*-netbsd*
3827 Xtensa GNU/Lunux xtensa*-*-linux*
3829 * Change in command line behavior -- corefiles vs. process ids.
3831 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3832 attaching to process NUMBER fails, GDB no longer attempts to open a
3833 core file named NUMBER. Attaching to a program using the -c option
3834 is no longer supported. Instead, use the '-p' or '--pid' options.
3836 * GDB can now be built as a native debugger for debugging Windows x86
3837 (mingw32) Portable Executable (PE) programs.
3839 * Pending breakpoints no longer change their number when their address
3842 * GDB now supports breakpoints with multiple locations,
3843 including breakpoints on C++ constructors, inside C++ templates,
3844 and in inlined functions.
3846 * GDB's ability to debug optimized code has been improved. GDB more
3847 accurately identifies function bodies and lexical blocks that occupy
3848 more than one contiguous range of addresses.
3850 * Target descriptions can now describe registers for PowerPC.
3852 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3853 registers on PowerPC targets.
3855 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3856 targets even when the libthread_db library is not available.
3858 * The GDB remote stub, gdbserver, now supports the new file transfer
3859 commands (remote put, remote get, and remote delete).
3861 * The GDB remote stub, gdbserver, now supports run and attach in
3862 extended-remote mode.
3864 * hppa*64*-*-hpux11* target broken
3865 The debugger is unable to start a program and fails with the following
3866 error: "Error trying to get information about dynamic linker".
3867 The gdb-6.7 release is also affected.
3869 * GDB now supports the --enable-targets= configure option to allow
3870 building a single GDB executable that supports multiple remote
3871 target architectures.
3873 * GDB now supports debugging C and C++ programs which use the
3874 Decimal Floating Point extension. In addition, the PowerPC target
3875 now has a set of pseudo-registers to inspect decimal float values
3876 stored in two consecutive float registers.
3878 * The -break-insert MI command can optionally create pending
3881 * Improved support for debugging Ada
3882 Many improvements to the Ada language support have been made. These
3884 - Better support for Ada2005 interface types
3885 - Improved handling of arrays and slices in general
3886 - Better support for Taft-amendment types
3887 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3889 - Improved command completion in Ada
3892 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3897 set print frame-arguments (all|scalars|none)
3898 show print frame-arguments
3899 The value of this variable can be changed to control which argument
3900 values should be printed by the debugger when displaying a frame.
3905 Transfer files to and from a remote target, and delete remote files.
3912 Transfer files to and from a remote target, and delete remote files.
3914 * New remote packets
3921 Open, close, read, write, and delete files on the remote system.
3924 Attach to an existing process on the remote system, in extended-remote
3928 Run a new process on the remote system, in extended-remote mode.
3930 *** Changes in GDB 6.7
3932 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3933 bfd, libiberty and opcodes, as revealed by static analysis donated by
3934 Coverity, Inc. (http://scan.coverity.com).
3936 * When looking up multiply-defined global symbols, GDB will now prefer the
3937 symbol definition in the current shared library if it was built using the
3938 -Bsymbolic linker option.
3940 * When the Text User Interface (TUI) is not configured, GDB will now
3941 recognize the -tui command-line option and print a message that the TUI
3944 * The GDB remote stub, gdbserver, now has lower overhead for high
3945 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3947 * GDB for MIPS targets now autodetects whether a remote target provides
3948 32-bit or 64-bit register values.
3950 * Support for C++ member pointers has been improved.
3952 * GDB now understands XML target descriptions, which specify the
3953 target's overall architecture. GDB can read a description from
3954 a local file or over the remote serial protocol.
3956 * Vectors of single-byte data use a new integer type which is not
3957 automatically displayed as character or string data.
3959 * The /s format now works with the print command. It displays
3960 arrays of single-byte integers and pointers to single-byte integers
3963 * Target descriptions can now describe target-specific registers,
3964 for architectures which have implemented the support (currently
3965 only ARM, M68K, and MIPS).
3967 * GDB and the GDB remote stub, gdbserver, now support the XScale
3970 * The GDB remote stub, gdbserver, has been updated to support
3971 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3972 has been rewritten to use the standard GDB remote protocol.
3974 * GDB can now step into C++ functions which are called through thunks.
3976 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3978 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3979 layout. It also supports a TextSeg= and DataSeg= response when only
3980 segment base addresses (rather than offsets) are available.
3982 * The /i format now outputs any trailing branch delay slot instructions
3983 immediately following the last instruction within the count specified.
3985 * The GDB remote protocol "T" stop reply packet now supports a
3986 "library" response. Combined with the new "qXfer:libraries:read"
3987 packet, this response allows GDB to debug shared libraries on targets
3988 where the operating system manages the list of loaded libraries (e.g.
3989 Windows and SymbianOS).
3991 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3992 (DLLs) on Windows and Windows CE targets.
3994 * GDB now supports a faster verification that a .debug file matches its binary
3995 according to its build-id signature, if the signature is present.
4001 Enable or disable hardware flow control (RTS/CTS) on the serial port
4002 when debugging using remote targets.
4004 set mem inaccessible-by-default
4005 show mem inaccessible-by-default
4006 If the target supplies a memory map, for instance via the remote
4007 protocol's "qXfer:memory-map:read" packet, setting this variable
4008 prevents GDB from accessing memory outside the memory map. This
4009 is useful for targets with memory mapped registers or which react
4010 badly to accesses of unmapped address space.
4012 set breakpoint auto-hw
4013 show breakpoint auto-hw
4014 If the target supplies a memory map, for instance via the remote
4015 protocol's "qXfer:memory-map:read" packet, setting this variable
4016 lets GDB use hardware breakpoints automatically for memory regions
4017 where it can not use software breakpoints. This covers both the
4018 "break" command and internal breakpoints used for other commands
4019 including "next" and "finish".
4022 catch exception unhandled
4023 Stop the program execution when Ada exceptions are raised.
4026 Stop the program execution when an Ada assertion failed.
4030 Set an alternate system root for target files. This is a more
4031 general version of "set solib-absolute-prefix", which is now
4032 an alias to "set sysroot".
4035 Provide extended SPU facility status information. This set of
4036 commands is available only when debugging the Cell/B.E. SPU
4039 * New native configurations
4041 OpenBSD/sh sh*-*openbsd*
4044 unset tdesc filename
4046 Use the specified local file as an XML target description, and do
4047 not query the target for its built-in description.
4051 OpenBSD/sh sh*-*-openbsd*
4052 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4053 Toshiba Media Processor mep-elf
4055 * New remote packets
4058 Ignore the specified signals; pass them directly to the debugged program
4059 without stopping other threads or reporting them to GDB.
4061 qXfer:features:read:
4062 Read an XML target description from the target, which describes its
4067 Read or write contents of an spufs file on the target system. These
4068 packets are available only on the Cell/B.E. SPU architecture.
4070 qXfer:libraries:read:
4071 Report the loaded shared libraries. Combined with new "T" packet
4072 response, this packet allows GDB to debug shared libraries on
4073 targets where the operating system manages the list of loaded
4074 libraries (e.g. Windows and SymbianOS).
4078 Support for these obsolete configurations has been removed.
4086 i[34567]86-*-lynxos*
4087 i[34567]86-*-netware*
4088 i[34567]86-*-sco3.2v5*
4089 i[34567]86-*-sco3.2v4*
4091 i[34567]86-*-sysv4.2*
4094 i[34567]86-*-unixware2*
4095 i[34567]86-*-unixware*
4104 * Other removed features
4111 Various m68k-only ROM monitors.
4118 Various Renesas ROM monitors and debugging interfaces for SH and
4123 Support for a Macraigor serial interface to on-chip debugging.
4124 GDB does not directly support the newer parallel or USB
4129 A debug information format. The predecessor to DWARF 2 and
4130 DWARF 3, which are still supported.
4132 Support for the HP aCC compiler on HP-UX/PA-RISC
4134 SOM-encapsulated symbolic debugging information, automatic
4135 invocation of pxdb, and the aCC custom C++ ABI. This does not
4136 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4137 with aCC can still be debugged on an assembly level.
4139 MIPS ".pdr" sections
4141 A MIPS-specific format used to describe stack frame layout
4142 in debugging information.
4146 GDB could work with an older version of Guile to debug
4147 the interpreter and Scheme programs running in it.
4149 set mips stack-arg-size
4150 set mips saved-gpreg-size
4152 Use "set mips abi" to control parameter passing for MIPS.
4154 *** Changes in GDB 6.6
4159 Cell Broadband Engine SPU spu-elf
4161 * GDB can now be configured as a cross-debugger targeting native Windows
4162 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4163 running on a Windows system over TCP/IP to debug Windows programs.
4165 * The GDB remote stub, gdbserver, has been updated to support Windows and
4166 Cygwin debugging. Both single-threaded and multi-threaded programs are
4169 * The "set trust-readonly-sections" command works again. This command was
4170 broken in GDB 6.3, 6.4, and 6.5.
4172 * The "load" command now supports writing to flash memory, if the remote
4173 stub provides the required support.
4175 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4176 longer requires symbolic debug information (e.g. DWARF-2).
4181 unset substitute-path
4182 show substitute-path
4183 Manage a list of substitution rules that GDB uses to rewrite the name
4184 of the directories where the sources are located. This can be useful
4185 for instance when the sources were moved to a different location
4186 between compilation and debugging.
4190 Print each CLI command as it is executed. Each command is prefixed with
4191 a number of `+' symbols representing the nesting depth.
4192 The source command now has a `-v' option to enable the same feature.
4196 The ARM Demon monitor support (RDP protocol, "target rdp").
4198 Kernel Object Display, an embedded debugging feature which only worked with
4199 an obsolete version of Cisco IOS.
4201 The 'set download-write-size' and 'show download-write-size' commands.
4203 * New remote packets
4206 Tell a stub about GDB client features, and request remote target features.
4207 The first feature implemented is PacketSize, which allows the target to
4208 specify the size of packets it can handle - to minimize the number of
4209 packets required and improve performance when connected to a remote
4213 Fetch an OS auxilliary vector from the remote stub. This packet is a
4214 more efficient replacement for qPart:auxv:read.
4216 qXfer:memory-map:read:
4217 Fetch a memory map from the remote stub, including information about
4218 RAM, ROM, and flash memory devices.
4223 Erase and program a flash memory device.
4225 * Removed remote packets
4228 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4229 used it, and only gdbserver implemented it.
4231 *** Changes in GDB 6.5
4235 Renesas M32C/M16C m32c-elf
4237 Morpho Technologies ms1 ms1-elf
4241 init-if-undefined Initialize a convenience variable, but
4242 only if it doesn't already have a value.
4244 The following commands are presently only implemented for native GNU/Linux:
4246 checkpoint Save a snapshot of the program state.
4248 restart <n> Return the program state to a
4249 previously saved state.
4251 info checkpoints List currently saved checkpoints.
4253 delete-checkpoint <n> Delete a previously saved checkpoint.
4255 set|show detach-on-fork Tell gdb whether to detach from a newly
4256 forked process, or to keep debugging it.
4258 info forks List forks of the user program that
4259 are available to be debugged.
4261 fork <n> Switch to debugging one of several
4262 forks of the user program that are
4263 available to be debugged.
4265 delete-fork <n> Delete a fork from the list of forks
4266 that are available to be debugged (and
4267 kill the forked process).
4269 detach-fork <n> Delete a fork from the list of forks
4270 that are available to be debugged (and
4271 allow the process to continue).
4275 Morpho Technologies ms2 ms1-elf
4277 * Improved Windows host support
4279 GDB now builds as a cross debugger hosted on i686-mingw32, including
4280 native console support, and remote communications using either
4281 network sockets or serial ports.
4283 * Improved Modula-2 language support
4285 GDB can now print most types in the Modula-2 syntax. This includes:
4286 basic types, set types, record types, enumerated types, range types,
4287 pointer types and ARRAY types. Procedure var parameters are correctly
4288 printed and hexadecimal addresses and character constants are also
4289 written in the Modula-2 syntax. Best results can be obtained by using
4290 GNU Modula-2 together with the -gdwarf-2 command line option.
4294 The ARM rdi-share module.
4296 The Netware NLM debug server.
4298 *** Changes in GDB 6.4
4300 * New native configurations
4302 OpenBSD/arm arm*-*-openbsd*
4303 OpenBSD/mips64 mips64-*-openbsd*
4307 Morpho Technologies ms1 ms1-elf
4309 * New command line options
4311 --batch-silent As for --batch, but totally silent.
4312 --return-child-result The debugger will exist with the same value
4313 the child (debugged) program exited with.
4314 --eval-command COMMAND, -ex COMMAND
4315 Execute a single GDB CLI command. This may be
4316 specified multiple times and in conjunction
4317 with the --command (-x) option.
4319 * Deprecated commands removed
4321 The following commands, that were deprecated in 2000, have been
4325 set|show arm disassembly-flavor set|show arm disassembler
4326 othernames set arm disassembler
4327 set|show remotedebug set|show debug remote
4328 set|show archdebug set|show debug arch
4329 set|show eventdebug set|show debug event
4332 * New BSD user-level threads support
4334 It is now possible to debug programs using the user-level threads
4335 library on OpenBSD and FreeBSD. Currently supported (target)
4338 FreeBSD/amd64 x86_64-*-freebsd*
4339 FreeBSD/i386 i386-*-freebsd*
4340 OpenBSD/i386 i386-*-openbsd*
4342 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4343 are not yet supported.
4345 * New support for Matsushita MN10300 w/sim added
4346 (Work in progress). mn10300-elf.
4348 * REMOVED configurations and files
4350 VxWorks and the XDR protocol *-*-vxworks
4351 Motorola MCORE mcore-*-*
4352 National Semiconductor NS32000 ns32k-*-*
4354 * New "set print array-indexes" command
4356 After turning this setting "on", GDB prints the index of each element
4357 when displaying arrays. The default is "off" to preserve the previous
4360 * VAX floating point support
4362 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4364 * User-defined command support
4366 In addition to using $arg0..$arg9 for argument passing, it is now possible
4367 to use $argc to determine now many arguments have been passed. See the
4368 section on user-defined commands in the user manual for more information.
4370 *** Changes in GDB 6.3:
4372 * New command line option
4374 GDB now accepts -l followed by a number to set the timeout for remote
4377 * GDB works with GCC -feliminate-dwarf2-dups
4379 GDB now supports a more compact representation of DWARF-2 debug
4380 information using DW_FORM_ref_addr references. These are produced
4381 by GCC with the option -feliminate-dwarf2-dups and also by some
4382 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4383 to use -feliminate-dwarf2-dups.
4385 * Internationalization
4387 When supported by the host system, GDB will be built with
4388 internationalization (libintl). The task of marking up the sources is
4389 continued, we're looking forward to our first translation.
4393 Initial support for debugging programs compiled with the GNAT
4394 implementation of the Ada programming language has been integrated
4395 into GDB. In this release, support is limited to expression evaluation.
4397 * New native configurations
4399 GNU/Linux/m32r m32r-*-linux-gnu
4403 GDB's remote protocol now includes support for the 'p' packet. This
4404 packet is used to fetch individual registers from a remote inferior.
4406 * END-OF-LIFE registers[] compatibility module
4408 GDB's internal register infrastructure has been completely rewritten.
4409 The new infrastructure making possible the implementation of key new
4410 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4413 GDB 6.3 will be the last release to include the the registers[]
4414 compatibility module that allowed out-of-date configurations to
4415 continue to work. This change directly impacts the following
4425 powerpc bdm protocol
4427 Unless there is activity to revive these configurations, they will be
4428 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4430 * OBSOLETE configurations and files
4432 Configurations that have been declared obsolete in this release have
4433 been commented out. Unless there is activity to revive these
4434 configurations, the next release of GDB will have their sources
4435 permanently REMOVED.
4444 *** Changes in GDB 6.2.1:
4446 * MIPS `break main; run' gave an heuristic-fence-post warning
4448 When attempting to run even a simple program, a warning about
4449 heuristic-fence-post being hit would be reported. This problem has
4452 * MIPS IRIX 'long double' crashed GDB
4454 When examining a long double variable, GDB would get a segmentation
4455 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4456 IRIX long double values).
4460 A bug in the VAX stack code was causing problems with the "next"
4461 command. This problem has been fixed.
4463 *** Changes in GDB 6.2:
4465 * Fix for ``many threads''
4467 On GNU/Linux systems that use the NPTL threads library, a program
4468 rapidly creating and deleting threads would confuse GDB leading to the
4471 ptrace: No such process.
4472 thread_db_get_info: cannot get thread info: generic error
4474 This problem has been fixed.
4476 * "-async" and "-noasync" options removed.
4478 Support for the broken "-noasync" option has been removed (it caused
4481 * New ``start'' command.
4483 This command runs the program until the begining of the main procedure.
4485 * New BSD Kernel Data Access Library (libkvm) interface
4487 Using ``target kvm'' it is now possible to debug kernel core dumps and
4488 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4489 platforms. Currently supported (native-only) configurations are:
4491 FreeBSD/amd64 x86_64-*-freebsd*
4492 FreeBSD/i386 i?86-*-freebsd*
4493 NetBSD/i386 i?86-*-netbsd*
4494 NetBSD/m68k m68*-*-netbsd*
4495 NetBSD/sparc sparc-*-netbsd*
4496 OpenBSD/amd64 x86_64-*-openbsd*
4497 OpenBSD/i386 i?86-*-openbsd*
4498 OpenBSD/m68k m68*-openbsd*
4499 OpenBSD/sparc sparc-*-openbsd*
4501 * Signal trampoline code overhauled
4503 Many generic problems with GDB's signal handling code have been fixed.
4504 These include: backtraces through non-contiguous stacks; recognition
4505 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4506 call; backtrace through a signal trampoline; step into and out of
4507 signal handlers; and single-stepping in the signal trampoline.
4509 Please note that kernel bugs are a limiting factor here. These
4510 features have been shown to work on an s390 GNU/Linux system that
4511 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4513 * Cygwin support for DWARF 2 added.
4515 * New native configurations
4517 GNU/Linux/hppa hppa*-*-linux*
4518 OpenBSD/hppa hppa*-*-openbsd*
4519 OpenBSD/m68k m68*-*-openbsd*
4520 OpenBSD/m88k m88*-*-openbsd*
4521 OpenBSD/powerpc powerpc-*-openbsd*
4522 NetBSD/vax vax-*-netbsd*
4523 OpenBSD/vax vax-*-openbsd*
4525 * END-OF-LIFE frame compatibility module
4527 GDB's internal frame infrastructure has been completely rewritten.
4528 The new infrastructure making it possible to support key new features
4529 including DWARF 2 Call Frame Information. To aid in the task of
4530 migrating old configurations to this new infrastructure, a
4531 compatibility module, that allowed old configurations to continue to
4532 work, was also included.
4534 GDB 6.2 will be the last release to include this frame compatibility
4535 module. This change directly impacts the following configurations:
4545 Unless there is activity to revive these configurations, they will be
4546 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4548 * REMOVED configurations and files
4550 Sun 3, running SunOS 3 m68*-*-sunos3*
4551 Sun 3, running SunOS 4 m68*-*-sunos4*
4552 Sun 2, running SunOS 3 m68000-*-sunos3*
4553 Sun 2, running SunOS 4 m68000-*-sunos4*
4554 Motorola 680x0 running LynxOS m68*-*-lynxos*
4555 AT&T 3b1/Unix pc m68*-att-*
4556 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4557 decstation mips-dec-* mips-little-*
4558 riscos mips-*-riscos* mips-*-sysv*
4559 sonymips mips-sony-*
4560 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4562 *** Changes in GDB 6.1.1:
4564 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4566 The TUI (Text-mode User Interface) is now built as part of a default
4567 GDB configuration. It is enabled by either selecting the TUI with the
4568 command line option "-i=tui" or by running the separate "gdbtui"
4569 program. For more information on the TUI, see the manual "Debugging
4572 * Pending breakpoint support (also included in GDB 6.1)
4574 Support has been added to allow you to specify breakpoints in shared
4575 libraries that have not yet been loaded. If a breakpoint location
4576 cannot be found, and the "breakpoint pending" option is set to auto,
4577 GDB queries you if you wish to make the breakpoint pending on a future
4578 shared-library load. If and when GDB resolves the breakpoint symbol,
4579 the pending breakpoint is removed as one or more regular breakpoints
4582 Pending breakpoints are very useful for GCJ Java debugging.
4584 * Fixed ISO-C build problems
4586 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4587 non ISO-C code that stopped them being built using a more strict ISO-C
4588 compiler (e.g., IBM's C compiler).
4590 * Fixed build problem on IRIX 5
4592 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4593 wasn't able to compile compile on an IRIX 5 system.
4595 * Added execute permission to gdb/gdbserver/configure
4597 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4598 permission. This bug would cause configure to fail on a number of
4599 systems (Solaris, IRIX). Ref: server/519.
4601 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4603 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4604 has been updated to use constant array sizes.
4606 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4608 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4609 its generated DWARF Call Frame Info. This encoding was causing GDB to
4610 panic, that panic has been fixed. Ref: gdb/1628.
4612 * Fixed a problem when examining parameters in shared library code.
4614 When examining parameters in optimized shared library code generated
4615 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4616 not available''. GDB now correctly displays the variable's value.
4618 *** Changes in GDB 6.1:
4620 * Removed --with-mmalloc
4622 Support for the mmalloc memory manager has been removed, as it
4623 conflicted with the internal gdb byte cache.
4625 * Changes in AMD64 configurations
4627 The AMD64 target now includes the %cs and %ss registers. As a result
4628 the AMD64 remote protocol has changed; this affects the floating-point
4629 and SSE registers. If you rely on those registers for your debugging,
4630 you should upgrade gdbserver on the remote side.
4632 * Revised SPARC target
4634 The SPARC target has been completely revised, incorporating the
4635 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4636 support for LynxOS and SunOS 4 has been dropped. Calling functions
4637 from within GDB on operating systems with a non-executable stack
4638 (Solaris, OpenBSD) now works.
4642 GDB has a new C++ demangler which does a better job on the mangled
4643 names generated by current versions of g++. It also runs faster, so
4644 with this and other changes gdb should now start faster on large C++
4647 * DWARF 2 Location Expressions
4649 GDB support for location expressions has been extended to support function
4650 arguments and frame bases. Older versions of GDB could crash when they
4653 * C++ nested types and namespaces
4655 GDB's support for nested types and namespaces in C++ has been
4656 improved, especially if you use the DWARF 2 debugging format. (This
4657 is the default for recent versions of GCC on most platforms.)
4658 Specifically, if you have a class "Inner" defined within a class or
4659 namespace "Outer", then GDB realizes that the class's name is
4660 "Outer::Inner", not simply "Inner". This should greatly reduce the
4661 frequency of complaints about not finding RTTI symbols. In addition,
4662 if you are stopped at inside of a function defined within a namespace,
4663 GDB modifies its name lookup accordingly.
4665 * New native configurations
4667 NetBSD/amd64 x86_64-*-netbsd*
4668 OpenBSD/amd64 x86_64-*-openbsd*
4669 OpenBSD/alpha alpha*-*-openbsd*
4670 OpenBSD/sparc sparc-*-openbsd*
4671 OpenBSD/sparc64 sparc64-*-openbsd*
4673 * New debugging protocols
4675 M32R with SDI protocol m32r-*-elf*
4677 * "set prompt-escape-char" command deleted.
4679 The command "set prompt-escape-char" has been deleted. This command,
4680 and its very obscure effet on GDB's prompt, was never documented,
4681 tested, nor mentioned in the NEWS file.
4683 * OBSOLETE configurations and files
4685 Configurations that have been declared obsolete in this release have
4686 been commented out. Unless there is activity to revive these
4687 configurations, the next release of GDB will have their sources
4688 permanently REMOVED.
4690 Sun 3, running SunOS 3 m68*-*-sunos3*
4691 Sun 3, running SunOS 4 m68*-*-sunos4*
4692 Sun 2, running SunOS 3 m68000-*-sunos3*
4693 Sun 2, running SunOS 4 m68000-*-sunos4*
4694 Motorola 680x0 running LynxOS m68*-*-lynxos*
4695 AT&T 3b1/Unix pc m68*-att-*
4696 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4697 decstation mips-dec-* mips-little-*
4698 riscos mips-*-riscos* mips-*-sysv*
4699 sonymips mips-sony-*
4700 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4702 * REMOVED configurations and files
4704 SGI Irix-4.x mips-sgi-irix4 or iris4
4705 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4706 Z8000 simulator z8k-zilog-none or z8ksim
4707 Matsushita MN10200 w/simulator mn10200-*-*
4708 H8/500 simulator h8500-hitachi-hms or h8500hms
4709 HP/PA running BSD hppa*-*-bsd*
4710 HP/PA running OSF/1 hppa*-*-osf*
4711 HP/PA Pro target hppa*-*-pro*
4712 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4713 386BSD i[3456]86-*-bsd*
4714 Sequent family i[3456]86-sequent-sysv4*
4715 i[3456]86-sequent-sysv*
4716 i[3456]86-sequent-bsd*
4717 SPARC running LynxOS sparc-*-lynxos*
4718 SPARC running SunOS 4 sparc-*-sunos4*
4719 Tsqware Sparclet sparclet-*-*
4720 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4722 *** Changes in GDB 6.0:
4726 Support for debugging the Objective-C programming language has been
4727 integrated into GDB.
4729 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4731 DWARF 2's Call Frame Information makes available compiler generated
4732 information that more exactly describes the program's run-time stack.
4733 By using this information, GDB is able to provide more robust stack
4736 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4737 have been updated to use a new backtrace mechanism which includes
4738 DWARF 2 CFI support.
4742 GDB's remote protocol has been extended to include support for hosted
4743 file I/O (where the remote target uses GDB's file system). See GDB's
4744 remote protocol documentation for details.
4746 * All targets using the new architecture framework.
4748 All of GDB's targets have been updated to use the new internal
4749 architecture framework. The way is now open for future GDB releases
4750 to include cross-architecture native debugging support (i386 on amd64,
4753 * GNU/Linux's Thread Local Storage (TLS)
4755 GDB now includes support for for the GNU/Linux implementation of
4756 per-thread variables.
4758 * GNU/Linux's Native POSIX Thread Library (NPTL)
4760 GDB's thread code has been updated to work with either the new
4761 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4763 * Separate debug info.
4765 GDB, in conjunction with BINUTILS, now supports a mechanism for
4766 automatically loading debug information from a separate file. Instead
4767 of shipping full debug and non-debug versions of system libraries,
4768 system integrators can now instead ship just the stripped libraries
4769 and optional debug files.
4771 * DWARF 2 Location Expressions
4773 DWARF 2 Location Expressions allow the compiler to more completely
4774 describe the location of variables (even in optimized code) to the
4777 GDB now includes preliminary support for location expressions (support
4778 for DW_OP_piece is still missing).
4782 A number of long standing bugs that caused GDB to die while starting a
4783 Java application have been fixed. GDB's Java support is now
4784 considered "useable".
4786 * GNU/Linux support for fork, vfork, and exec.
4788 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4789 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4792 * GDB supports logging output to a file
4794 There are two new commands, "set logging" and "show logging", which can be
4795 used to capture GDB's output to a file.
4797 * The meaning of "detach" has changed for gdbserver
4799 The "detach" command will now resume the application, as documented. To
4800 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4803 * d10v, m68hc11 `regs' command deprecated
4805 The `info registers' command has been updated so that it displays the
4806 registers using a format identical to the old `regs' command.
4810 A new command, "maint set profile on/off", has been added. This command can
4811 be used to enable or disable profiling while running GDB, to profile a
4812 session or a set of commands. In addition there is a new configure switch,
4813 "--enable-profiling", which will cause GDB to be compiled with profiling
4814 data, for more informative profiling results.
4816 * Default MI syntax changed to "mi2".
4818 The default MI (machine interface) syntax, enabled by the command line
4819 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4820 "mi1", can be enabled by specifying the option "-i=mi1".
4822 Support for the original "mi0" syntax (included in GDB 5.0) has been
4825 Fix for gdb/192: removed extraneous space when displaying frame level.
4826 Fix for gdb/672: update changelist is now output in mi list format.
4827 Fix for gdb/702: a -var-assign that updates the value now shows up
4828 in a subsequent -var-update.
4830 * New native configurations.
4832 FreeBSD/amd64 x86_64-*-freebsd*
4834 * Multi-arched targets.
4836 HP/PA HPUX11 hppa*-*-hpux*
4837 Renesas M32R/D w/simulator m32r-*-elf*
4839 * OBSOLETE configurations and files
4841 Configurations that have been declared obsolete in this release have
4842 been commented out. Unless there is activity to revive these
4843 configurations, the next release of GDB will have their sources
4844 permanently REMOVED.
4846 Z8000 simulator z8k-zilog-none or z8ksim
4847 Matsushita MN10200 w/simulator mn10200-*-*
4848 H8/500 simulator h8500-hitachi-hms or h8500hms
4849 HP/PA running BSD hppa*-*-bsd*
4850 HP/PA running OSF/1 hppa*-*-osf*
4851 HP/PA Pro target hppa*-*-pro*
4852 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4853 Sequent family i[3456]86-sequent-sysv4*
4854 i[3456]86-sequent-sysv*
4855 i[3456]86-sequent-bsd*
4856 Tsqware Sparclet sparclet-*-*
4857 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4859 * REMOVED configurations and files
4862 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4863 IBM AIX PS/2 i[3456]86-*-aix
4864 i386 running Mach 3.0 i[3456]86-*-mach3*
4865 i386 running Mach i[3456]86-*-mach*
4866 i386 running OSF/1 i[3456]86-*osf1mk*
4867 HP/Apollo 68k Family m68*-apollo*-sysv*,
4869 m68*-hp-bsd*, m68*-hp-hpux*
4870 Argonaut Risc Chip (ARC) arc-*-*
4871 Mitsubishi D30V d30v-*-*
4872 Fujitsu FR30 fr30-*-elf*
4873 OS/9000 i[34]86-*-os9k
4874 I960 with MON960 i960-*-coff
4876 * MIPS $fp behavior changed
4878 The convenience variable $fp, for the MIPS, now consistently returns
4879 the address of the current frame's base. Previously, depending on the
4880 context, $fp could refer to either $sp or the current frame's base
4881 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4882 The GNU Source-Level Debugger''.
4884 *** Changes in GDB 5.3:
4886 * GNU/Linux shared library multi-threaded performance improved.
4888 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4889 `/proc', in preference to `ptrace' for memory reads. This may result
4890 in an improvement in the start-up time of multi-threaded, shared
4891 library applications when run under GDB. One GDB user writes: ``loads
4892 shared libs like mad''.
4894 * ``gdbserver'' now supports multi-threaded applications on some targets
4896 Support for debugging multi-threaded applications which use
4897 the GNU/Linux LinuxThreads package has been added for
4898 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4899 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4901 * GDB now supports C/C++ preprocessor macros.
4903 GDB now expands preprocessor macro invocations in C/C++ expressions,
4904 and provides various commands for showing macro definitions and how
4907 The new command `macro expand EXPRESSION' expands any macro
4908 invocations in expression, and shows the result.
4910 The new command `show macro MACRO-NAME' shows the definition of the
4911 macro named MACRO-NAME, and where it was defined.
4913 Most compilers don't include information about macros in the debugging
4914 information by default. In GCC 3.1, for example, you need to compile
4915 your program with the options `-gdwarf-2 -g3'. If the macro
4916 information is present in the executable, GDB will read it.
4918 * Multi-arched targets.
4920 DEC Alpha (partial) alpha*-*-*
4921 DEC VAX (partial) vax-*-*
4923 National Semiconductor NS32000 (partial) ns32k-*-*
4924 Motorola 68000 (partial) m68k-*-*
4925 Motorola MCORE mcore-*-*
4929 Fujitsu FRV architecture added by Red Hat frv*-*-*
4932 * New native configurations
4934 Alpha NetBSD alpha*-*-netbsd*
4935 SH NetBSD sh*-*-netbsdelf*
4936 MIPS NetBSD mips*-*-netbsd*
4937 UltraSPARC NetBSD sparc64-*-netbsd*
4939 * OBSOLETE configurations and files
4941 Configurations that have been declared obsolete in this release have
4942 been commented out. Unless there is activity to revive these
4943 configurations, the next release of GDB will have their sources
4944 permanently REMOVED.
4946 Mitsubishi D30V d30v-*-*
4947 OS/9000 i[34]86-*-os9k
4948 IBM AIX PS/2 i[3456]86-*-aix
4949 Fujitsu FR30 fr30-*-elf*
4950 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4951 Argonaut Risc Chip (ARC) arc-*-*
4952 i386 running Mach 3.0 i[3456]86-*-mach3*
4953 i386 running Mach i[3456]86-*-mach*
4954 i386 running OSF/1 i[3456]86-*osf1mk*
4955 HP/Apollo 68k Family m68*-apollo*-sysv*,
4957 m68*-hp-bsd*, m68*-hp-hpux*
4958 I960 with MON960 i960-*-coff
4960 * OBSOLETE languages
4962 CHILL, a Pascal like language used by telecommunications companies.
4964 * REMOVED configurations and files
4966 AMD 29k family via UDI a29k-amd-udi, udi29k
4967 A29K VxWorks a29k-*-vxworks
4968 AMD 29000 embedded, using EBMON a29k-none-none
4969 AMD 29000 embedded with COFF a29k-none-coff
4970 AMD 29000 embedded with a.out a29k-none-aout
4972 testsuite/gdb.hp/gdb.threads-hp/ directory
4974 * New command "set max-user-call-depth <nnn>"
4976 This command allows the user to limit the call depth of user-defined
4977 commands. The default is 1024.
4979 * Changes in FreeBSD/i386 native debugging.
4981 Support for the "generate-core-file" has been added.
4983 * New commands "dump", "append", and "restore".
4985 These commands allow data to be copied from target memory
4986 to a bfd-format or binary file (dump and append), and back
4987 from a file into memory (restore).
4989 * Improved "next/step" support on multi-processor Alpha Tru64.
4991 The previous single-step mechanism could cause unpredictable problems,
4992 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4993 of a software single-step mechanism prevents this.
4995 *** Changes in GDB 5.2.1:
5003 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5004 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5005 Fix, by Joel Brobecker imported from mainline.
5007 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5008 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5009 Fix, by Fred Fish, imported from mainline.
5011 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5012 Surprisingly enough, it works now.
5013 By Michal Ludvig, imported from mainline.
5015 i386 hardware watchpoint support:
5016 avoid misses on second run for some targets.
5017 By Pierre Muller, imported from mainline.
5019 *** Changes in GDB 5.2:
5021 * New command "set trust-readonly-sections on[off]".
5023 This command is a hint that tells gdb that read-only sections
5024 really are read-only (ie. that their contents will not change).
5025 In this mode, gdb will go to the object file rather than the
5026 target to read memory from read-only sections (such as ".text").
5027 This can be a significant performance improvement on some
5028 (notably embedded) targets.
5030 * New command "generate-core-file" (or "gcore").
5032 This new gdb command allows the user to drop a core file of the child
5033 process state at any time. So far it's been implemented only for
5034 GNU/Linux and Solaris, but should be relatively easily ported to other
5035 hosts. Argument is core file name (defaults to core.<pid>).
5037 * New command line option
5039 GDB now accepts --pid or -p followed by a process id.
5041 * Change in command line behavior -- corefiles vs. process ids.
5043 There is a subtle behavior in the way in which GDB handles
5044 command line arguments. The first non-flag argument is always
5045 a program to debug, but the second non-flag argument may either
5046 be a corefile or a process id. Previously, GDB would attempt to
5047 open the second argument as a corefile, and if that failed, would
5048 issue a superfluous error message and then attempt to attach it as
5049 a process. Now, if the second argument begins with a non-digit,
5050 it will be treated as a corefile. If it begins with a digit,
5051 GDB will attempt to attach it as a process, and if no such process
5052 is found, will then attempt to open it as a corefile.
5054 * Changes in ARM configurations.
5056 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5057 configuration is fully multi-arch.
5059 * New native configurations
5061 ARM NetBSD arm*-*-netbsd*
5062 x86 OpenBSD i[3456]86-*-openbsd*
5063 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5064 Sparc64 running FreeBSD sparc64-*-freebsd*
5068 Sanyo XStormy16 xstormy16-elf
5070 * OBSOLETE configurations and files
5072 Configurations that have been declared obsolete in this release have
5073 been commented out. Unless there is activity to revive these
5074 configurations, the next release of GDB will have their sources
5075 permanently REMOVED.
5077 AMD 29k family via UDI a29k-amd-udi, udi29k
5078 A29K VxWorks a29k-*-vxworks
5079 AMD 29000 embedded, using EBMON a29k-none-none
5080 AMD 29000 embedded with COFF a29k-none-coff
5081 AMD 29000 embedded with a.out a29k-none-aout
5083 testsuite/gdb.hp/gdb.threads-hp/ directory
5085 * REMOVED configurations and files
5087 TI TMS320C80 tic80-*-*
5089 PowerPC Solaris powerpcle-*-solaris*
5090 PowerPC Windows NT powerpcle-*-cygwin32
5091 PowerPC Netware powerpc-*-netware*
5092 Harris/CXUX m88k m88*-harris-cxux*
5093 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5094 ns32k-utek-sysv* ns32k-utek-*
5095 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5096 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5097 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5098 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5099 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5101 * Changes to command line processing
5103 The new `--args' feature can be used to specify command-line arguments
5104 for the inferior from gdb's command line.
5106 * Changes to key bindings
5108 There is a new `operate-and-get-next' function bound to `C-o'.
5110 *** Changes in GDB 5.1.1
5112 Fix compile problem on DJGPP.
5114 Fix a problem with floating-point registers on the i386 being
5117 Fix to stop GDB crashing on .debug_str debug info.
5119 Numerous documentation fixes.
5121 Numerous testsuite fixes.
5123 *** Changes in GDB 5.1:
5125 * New native configurations
5127 Alpha FreeBSD alpha*-*-freebsd*
5128 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5129 MIPS GNU/Linux mips*-*-linux*
5130 MIPS SGI Irix 6.x mips*-sgi-irix6*
5131 ia64 AIX ia64-*-aix*
5132 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5136 Motorola 68HC11 and 68HC12 m68hc11-elf
5138 UltraSparc running GNU/Linux sparc64-*-linux*
5140 * OBSOLETE configurations and files
5142 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5143 Harris/CXUX m88k m88*-harris-cxux*
5144 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5145 ns32k-utek-sysv* ns32k-utek-*
5146 TI TMS320C80 tic80-*-*
5148 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5149 PowerPC Solaris powerpcle-*-solaris*
5150 PowerPC Windows NT powerpcle-*-cygwin32
5151 PowerPC Netware powerpc-*-netware*
5152 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5153 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5154 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5155 Apple Macintosh (MPW) host N/A
5157 stuff.c (Program to stuff files into a specially prepared space in kdb)
5158 kdb-start.c (Main loop for the standalone kernel debugger)
5160 Configurations that have been declared obsolete in this release have
5161 been commented out. Unless there is activity to revive these
5162 configurations, the next release of GDB will have their sources
5163 permanently REMOVED.
5165 * REMOVED configurations and files
5167 Altos 3068 m68*-altos-*
5168 Convex c1-*-*, c2-*-*
5170 ARM RISCix arm-*-* (as host)
5174 * GDB has been converted to ISO C.
5176 GDB's source code has been converted to ISO C. In particular, the
5177 sources are fully protoized, and rely on standard headers being
5182 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5184 * The MI enabled by default.
5186 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5187 revised and enabled by default. Packages which use GDB as a debugging
5188 engine behind a UI or another front end are encouraged to switch to
5189 using the GDB/MI interface, instead of the old annotations interface
5190 which is now deprecated.
5192 * Support for debugging Pascal programs.
5194 GDB now includes support for debugging Pascal programs. The following
5195 main features are supported:
5197 - Pascal-specific data types such as sets;
5199 - automatic recognition of Pascal sources based on file-name
5202 - Pascal-style display of data types, variables, and functions;
5204 - a Pascal expression parser.
5206 However, some important features are not yet supported.
5208 - Pascal string operations are not supported at all;
5210 - there are some problems with boolean types;
5212 - Pascal type hexadecimal constants are not supported
5213 because they conflict with the internal variables format;
5215 - support for Pascal objects and classes is not full yet;
5217 - unlike Pascal, GDB is case-sensitive for symbol names.
5219 * Changes in completion.
5221 Commands such as `shell', `run' and `set args', which pass arguments
5222 to inferior programs, now complete on file names, similar to what
5223 users expect at the shell prompt.
5225 Commands which accept locations, such as `disassemble', `print',
5226 `breakpoint', `until', etc. now complete on filenames as well as
5227 program symbols. Thus, if you type "break foob TAB", and the source
5228 files linked into the programs include `foobar.c', that file name will
5229 be one of the candidates for completion. However, file names are not
5230 considered for completion after you typed a colon that delimits a file
5231 name from a name of a function in that file, as in "break foo.c:bar".
5233 `set demangle-style' completes on available demangling styles.
5235 * New platform-independent commands:
5237 It is now possible to define a post-hook for a command as well as a
5238 hook that runs before the command. For more details, see the
5239 documentation of `hookpost' in the GDB manual.
5241 * Changes in GNU/Linux native debugging.
5243 Support for debugging multi-threaded programs has been completely
5244 revised for all platforms except m68k and sparc. You can now debug as
5245 many threads as your system allows you to have.
5247 Attach/detach is supported for multi-threaded programs.
5249 Support for SSE registers was added for x86. This doesn't work for
5250 multi-threaded programs though.
5252 * Changes in MIPS configurations.
5254 Multi-arch support is enabled for all MIPS configurations.
5256 GDB can now be built as native debugger on SGI Irix 6.x systems for
5257 debugging n32 executables. (Debugging 64-bit executables is not yet
5260 * Unified support for hardware watchpoints in all x86 configurations.
5262 Most (if not all) native x86 configurations support hardware-assisted
5263 breakpoints and watchpoints in a unified manner. This support
5264 implements debug register sharing between watchpoints, which allows to
5265 put a virtually infinite number of watchpoints on the same address,
5266 and also supports watching regions up to 16 bytes with several debug
5269 The new maintenance command `maintenance show-debug-regs' toggles
5270 debugging print-outs in functions that insert, remove, and test
5271 watchpoints and hardware breakpoints.
5273 * Changes in the DJGPP native configuration.
5275 New command ``info dos sysinfo'' displays assorted information about
5276 the CPU, OS, memory, and DPMI server.
5278 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5279 display information about segment descriptors stored in GDT, LDT, and
5282 New commands ``info dos pde'' and ``info dos pte'' display entries
5283 from Page Directory and Page Tables (for now works with CWSDPMI only).
5284 New command ``info dos address-pte'' displays the Page Table entry for
5285 a given linear address.
5287 GDB can now pass command lines longer than 126 characters to the
5288 program being debugged (requires an update to the libdbg.a library
5289 which is part of the DJGPP development kit).
5291 DWARF2 debug info is now supported.
5293 It is now possible to `step' and `next' through calls to `longjmp'.
5295 * Changes in documentation.
5297 All GDB documentation was converted to GFDL, the GNU Free
5298 Documentation License.
5300 Tracepoints-related commands are now fully documented in the GDB
5303 TUI, the Text-mode User Interface, is now documented in the manual.
5305 Tracepoints-related commands are now fully documented in the GDB
5308 The "GDB Internals" manual now has an index. It also includes
5309 documentation of `ui_out' functions, GDB coding standards, x86
5310 hardware watchpoints, and memory region attributes.
5312 * GDB's version number moved to ``version.in''
5314 The Makefile variable VERSION has been replaced by the file
5315 ``version.in''. People creating GDB distributions should update the
5316 contents of this file.
5320 GUD support is now a standard part of the EMACS distribution.
5322 *** Changes in GDB 5.0:
5324 * Improved support for debugging FP programs on x86 targets
5326 Unified and much-improved support for debugging floating-point
5327 programs on all x86 targets. In particular, ``info float'' now
5328 displays the FP registers in the same format on all x86 targets, with
5329 greater level of detail.
5331 * Improvements and bugfixes in hardware-assisted watchpoints
5333 It is now possible to watch array elements, struct members, and
5334 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5335 on x86 targets no longer erroneously trigger when the address is
5338 * Improvements in the native DJGPP version of GDB
5340 The distribution now includes all the scripts and auxiliary files
5341 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5342 machines ``out of the box''.
5344 The DJGPP version can now debug programs that use signals. It is
5345 possible to catch signals that happened in the debuggee, deliver
5346 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5347 would kill the program being debugged.) Programs that hook hardware
5348 interrupts (keyboard, timer, etc.) can also be debugged.
5350 It is now possible to debug DJGPP programs that redirect their
5351 standard handles or switch them to raw (as opposed to cooked) mode, or
5352 even close them. The command ``run < foo > bar'' works as expected,
5353 and ``info terminal'' reports useful information about the debuggee's
5354 terminal, including raw/cooked mode, redirection, etc.
5356 The DJGPP version now uses termios functions for console I/O, which
5357 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5360 DOS-style file names with drive letters are now fully supported by
5363 It is now possible to debug DJGPP programs that switch their working
5364 directory. It is also possible to rerun the debuggee any number of
5365 times without restarting GDB; thus, you can use the same setup,
5366 breakpoints, etc. for many debugging sessions.
5368 * New native configurations
5370 ARM GNU/Linux arm*-*-linux*
5371 PowerPC GNU/Linux powerpc-*-linux*
5375 Motorola MCore mcore-*-*
5376 x86 VxWorks i[3456]86-*-vxworks*
5377 PowerPC VxWorks powerpc-*-vxworks*
5378 TI TMS320C80 tic80-*-*
5380 * OBSOLETE configurations
5382 Altos 3068 m68*-altos-*
5383 Convex c1-*-*, c2-*-*
5385 ARM RISCix arm-*-* (as host)
5388 Configurations that have been declared obsolete will be commented out,
5389 but the code will be left in place. If there is no activity to revive
5390 these configurations before the next release of GDB, the sources will
5391 be permanently REMOVED.
5393 * Gould support removed
5395 Support for the Gould PowerNode and NP1 has been removed.
5397 * New features for SVR4
5399 On SVR4 native platforms (such as Solaris), if you attach to a process
5400 without first loading a symbol file, GDB will now attempt to locate and
5401 load symbols from the running process's executable file.
5403 * Many C++ enhancements
5405 C++ support has been greatly improved. Overload resolution now works properly
5406 in almost all cases. RTTI support is on the way.
5408 * Remote targets can connect to a sub-program
5410 A popen(3) style serial-device has been added. This device starts a
5411 sub-process (such as a stand-alone simulator) and then communicates
5412 with that. The sub-program to run is specified using the syntax
5413 ``|<program> <args>'' vis:
5415 (gdb) set remotedebug 1
5416 (gdb) target extended-remote |mn10300-elf-sim program-args
5418 * MIPS 64 remote protocol
5420 A long standing bug in the mips64 remote protocol where by GDB
5421 expected certain 32 bit registers (ex SR) to be transfered as 32
5422 instead of 64 bits has been fixed.
5424 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5425 added to provide backward compatibility with older versions of GDB.
5427 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5429 The command ``set remotebinarydownload'' command has been replaced by
5430 ``set remote X-packet''. Other commands in ``set remote'' family
5431 include ``set remote P-packet''.
5433 * Breakpoint commands accept ranges.
5435 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5436 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5437 ``tracepoint passcount'' also accepts a range of tracepoints.
5439 * ``apropos'' command added.
5441 The ``apropos'' command searches through command names and
5442 documentation strings, printing out matches, making it much easier to
5443 try to find a command that does what you are looking for.
5447 A new machine oriented interface (MI) has been added to GDB. This
5448 interface is designed for debug environments running GDB as a separate
5449 process. This is part of the long term libGDB project. See the
5450 "GDB/MI" chapter of the GDB manual for further information. It can be
5451 enabled by configuring with:
5453 .../configure --enable-gdbmi
5455 *** Changes in GDB-4.18:
5457 * New native configurations
5459 HP-UX 10.20 hppa*-*-hpux10.20
5460 HP-UX 11.x hppa*-*-hpux11.0*
5461 M68K GNU/Linux m68*-*-linux*
5465 Fujitsu FR30 fr30-*-elf*
5466 Intel StrongARM strongarm-*-*
5467 Mitsubishi D30V d30v-*-*
5469 * OBSOLETE configurations
5471 Gould PowerNode, NP1 np1-*-*, pn-*-*
5473 Configurations that have been declared obsolete will be commented out,
5474 but the code will be left in place. If there is no activity to revive
5475 these configurations before the next release of GDB, the sources will
5476 be permanently REMOVED.
5480 As a compatibility experiment, GDB's source files buildsym.h and
5481 buildsym.c have been converted to pure standard C, no longer
5482 containing any K&R compatibility code. We believe that all systems in
5483 use today either come with a standard C compiler, or have a GCC port
5484 available. If this is not true, please report the affected
5485 configuration to bug-gdb@gnu.org immediately. See the README file for
5486 information about getting a standard C compiler if you don't have one
5491 GDB now uses readline 2.2.
5493 * set extension-language
5495 You can now control the mapping between filename extensions and source
5496 languages by using the `set extension-language' command. For instance,
5497 you can ask GDB to treat .c files as C++ by saying
5498 set extension-language .c c++
5499 The command `info extensions' lists all of the recognized extensions
5500 and their associated languages.
5502 * Setting processor type for PowerPC and RS/6000
5504 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5505 you can use the `set processor' command to specify what variant of the
5506 PowerPC family you are debugging. The command
5510 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5511 following PowerPC and RS6000 variants:
5513 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5514 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5516 403GC IBM PowerPC 403GC
5517 505 Motorola PowerPC 505
5518 860 Motorola PowerPC 860 or 850
5519 601 Motorola PowerPC 601
5520 602 Motorola PowerPC 602
5521 603 Motorola/IBM PowerPC 603 or 603e
5522 604 Motorola PowerPC 604 or 604e
5523 750 Motorola/IBM PowerPC 750 or 750
5525 At the moment, this command just tells GDB what to name the
5526 special-purpose processor registers. Since almost all the affected
5527 registers are inaccessible to user-level programs, this command is
5528 only useful for remote debugging in its present form.
5532 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5533 more extensive support for HP-UX. Added features include shared
5534 library support, kernel threads and hardware watchpoints for 11.00,
5535 support for HP's ANSI C and C++ compilers, and a compatibility mode
5536 for xdb and dbx commands.
5540 HP's donation includes the new concept of catchpoints, which is a
5541 generalization of the old catch command. On HP-UX, it is now possible
5542 to catch exec, fork, and vfork, as well as library loading.
5544 This means that the existing catch command has changed; its first
5545 argument now specifies the type of catch to be set up. See the
5546 output of "help catch" for a list of catchpoint types.
5548 * Debugging across forks
5550 On HP-UX, you can choose which process to debug when a fork() happens
5555 HP has donated a curses-based terminal user interface (TUI). To get
5556 it, build with --enable-tui. Although this can be enabled for any
5557 configuration, at present it only works for native HP debugging.
5559 * GDB remote protocol additions
5561 A new protocol packet 'X' that writes binary data is now available.
5562 Default behavior is to try 'X', then drop back to 'M' if the stub
5563 fails to respond. The settable variable `remotebinarydownload'
5564 allows explicit control over the use of 'X'.
5566 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5567 full 64-bit address. The command
5569 set remoteaddresssize 32
5571 can be used to revert to the old behaviour. For existing remote stubs
5572 the change should not be noticed, as the additional address information
5575 In order to assist in debugging stubs, you may use the maintenance
5576 command `packet' to send any text string to the stub. For instance,
5578 maint packet heythere
5580 sends the packet "$heythere#<checksum>". Note that it is very easy to
5581 disrupt a debugging session by sending the wrong packet at the wrong
5584 The compare-sections command allows you to compare section data on the
5585 target to what is in the executable file without uploading or
5586 downloading, by comparing CRC checksums.
5588 * Tracing can collect general expressions
5590 You may now collect general expressions at tracepoints. This requires
5591 further additions to the target-side stub; see tracepoint.c and
5592 doc/agentexpr.texi for further details.
5594 * mask-address variable for Mips
5596 For Mips targets, you may control the zeroing of the upper 32 bits of
5597 a 64-bit address by entering `set mask-address on'. This is mainly
5598 of interest to users of embedded R4xxx and R5xxx processors.
5600 * Higher serial baud rates
5602 GDB's serial code now allows you to specify baud rates 57600, 115200,
5603 230400, and 460800 baud. (Note that your host system may not be able
5604 to achieve all of these rates.)
5608 The i960 configuration now includes an initial implementation of a
5609 builtin simulator, contributed by Jim Wilson.
5612 *** Changes in GDB-4.17:
5614 * New native configurations
5616 Alpha GNU/Linux alpha*-*-linux*
5617 Unixware 2.x i[3456]86-unixware2*
5618 Irix 6.x mips*-sgi-irix6*
5619 PowerPC GNU/Linux powerpc-*-linux*
5620 PowerPC Solaris powerpcle-*-solaris*
5621 Sparc GNU/Linux sparc-*-linux*
5622 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5626 Argonaut Risc Chip (ARC) arc-*-*
5627 Hitachi H8/300S h8300*-*-*
5628 Matsushita MN10200 w/simulator mn10200-*-*
5629 Matsushita MN10300 w/simulator mn10300-*-*
5630 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5631 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5632 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5633 Mitsubishi D10V w/simulator d10v-*-*
5634 Mitsubishi M32R/D w/simulator m32r-*-elf*
5635 Tsqware Sparclet sparclet-*-*
5636 NEC V850 w/simulator v850-*-*
5638 * New debugging protocols
5640 ARM with RDI protocol arm*-*-*
5641 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5642 DDB and LSI variants of PMON protocol mips*-*-*
5643 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5644 PowerPC with SDS protocol powerpc{,le}-*-eabi
5645 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5649 All configurations can now understand and use the DWARF 2 debugging
5650 format. The choice is automatic, if the symbol file contains DWARF 2
5655 GDB now includes basic Java language support. This support is
5656 only useful with Java compilers that produce native machine code.
5658 * solib-absolute-prefix and solib-search-path
5660 For SunOS and SVR4 shared libraries, you may now set the prefix for
5661 loading absolute shared library symbol files, and the search path for
5662 locating non-absolute shared library symbol files.
5664 * Live range splitting
5666 GDB can now effectively debug code for which GCC has performed live
5667 range splitting as part of its optimization. See gdb/doc/LRS for
5668 more details on the expected format of the stabs information.
5672 GDB's support for the GNU Hurd, including thread debugging, has been
5673 updated to work with current versions of the Hurd.
5677 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5678 instruction set. ARM GDB automatically detects when Thumb
5679 instructions are in use, and adjusts disassembly and backtracing
5684 GDB's MIPS target configurations now handle the MIP16 16-bit
5689 GDB now includes support for overlays; if an executable has been
5690 linked such that multiple sections are based at the same address, GDB
5691 will decide which section to use for symbolic info. You can choose to
5692 control the decision manually, using overlay commands, or implement
5693 additional target-side support and use "overlay load-target" to bring
5694 in the overlay mapping. Do "help overlay" for more detail.
5698 The command "info symbol <address>" displays information about
5699 the symbol at the specified address.
5703 The standard remote protocol now includes an extension that allows
5704 asynchronous collection and display of trace data. This requires
5705 extensive support in the target-side debugging stub. Tracing mode
5706 includes a new interaction mode in GDB and new commands: see the
5707 file tracepoint.c for more details.
5711 Configurations for embedded MIPS now include a simulator contributed
5712 by Cygnus Solutions. The simulator supports the instruction sets
5713 of most MIPS variants.
5717 Sparc configurations may now include the ERC32 simulator contributed
5718 by the European Space Agency. The simulator is not built into
5719 Sparc targets by default; configure with --enable-sim to include it.
5723 For target configurations that may include multiple variants of a
5724 basic architecture (such as MIPS and SH), you may now set the
5725 architecture explicitly. "set arch" sets, "info arch" lists
5726 the possible architectures.
5728 *** Changes in GDB-4.16:
5730 * New native configurations
5732 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5733 M68K NetBSD m68k-*-netbsd*
5734 PowerPC AIX 4.x powerpc-*-aix*
5735 PowerPC MacOS powerpc-*-macos*
5736 PowerPC Windows NT powerpcle-*-cygwin32
5737 RS/6000 AIX 4.x rs6000-*-aix4*
5741 ARM with RDP protocol arm-*-*
5742 I960 with MON960 i960-*-coff
5743 MIPS VxWorks mips*-*-vxworks*
5744 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5745 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5747 Matra Sparclet sparclet-*-*
5751 The powerpc-eabi configuration now includes the PSIM simulator,
5752 contributed by Andrew Cagney, with assistance from Mike Meissner.
5753 PSIM is a very elaborate model of the PowerPC, including not only
5754 basic instruction set execution, but also details of execution unit
5755 performance and I/O hardware. See sim/ppc/README for more details.
5759 GDB now works with Solaris 2.5.
5761 * Windows 95/NT native
5763 GDB will now work as a native debugger on Windows 95 and Windows NT.
5764 To build it from source, you must use the "gnu-win32" environment,
5765 which uses a DLL to emulate enough of Unix to run the GNU tools.
5766 Further information, binaries, and sources are available at
5767 ftp.cygnus.com, under pub/gnu-win32.
5769 * dont-repeat command
5771 If a user-defined command includes the command `dont-repeat', then the
5772 command will not be repeated if the user just types return. This is
5773 useful if the command is time-consuming to run, so that accidental
5774 extra keystrokes don't run the same command many times.
5776 * Send break instead of ^C
5778 The standard remote protocol now includes an option to send a break
5779 rather than a ^C to the target in order to interrupt it. By default,
5780 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5782 * Remote protocol timeout
5784 The standard remote protocol includes a new variable `remotetimeout'
5785 that allows you to set the number of seconds before GDB gives up trying
5786 to read from the target. The default value is 2.
5788 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5790 By default GDB will automatically keep track of objects as they are
5791 loaded and unloaded by the dynamic linker. By using the command `set
5792 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5793 when shared library events occur, thus allowing you to set breakpoints
5794 in shared libraries which are explicitly loaded by the inferior.
5796 Note this feature does not work on hpux8. On hpux9 you must link
5797 /usr/lib/end.o into your program. This feature should work
5798 automatically on hpux10.
5800 * Irix 5.x hardware watchpoint support
5802 Irix 5 configurations now support the use of hardware watchpoints.
5804 * Mips protocol "SYN garbage limit"
5806 When debugging a Mips target using the `target mips' protocol, you
5807 may set the number of characters that GDB will ignore by setting
5808 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5809 every character. The default value is 1050.
5811 * Recording and replaying remote debug sessions
5813 If you set `remotelogfile' to the name of a file, gdb will write to it
5814 a recording of a remote debug session. This recording may then be
5815 replayed back to gdb using "gdbreplay". See gdbserver/README for
5816 details. This is useful when you have a problem with GDB while doing
5817 remote debugging; you can make a recording of the session and send it
5818 to someone else, who can then recreate the problem.
5820 * Speedups for remote debugging
5822 GDB includes speedups for downloading and stepping MIPS systems using
5823 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5824 and more efficient S-record downloading.
5826 * Memory use reductions and statistics collection
5828 GDB now uses less memory and reports statistics about memory usage.
5829 Try the `maint print statistics' command, for example.
5831 *** Changes in GDB-4.15:
5833 * Psymtabs for XCOFF
5835 The symbol reader for AIX GDB now uses partial symbol tables. This
5836 can greatly improve startup time, especially for large executables.
5838 * Remote targets use caching
5840 Remote targets now use a data cache to speed up communication with the
5841 remote side. The data cache could lead to incorrect results because
5842 it doesn't know about volatile variables, thus making it impossible to
5843 debug targets which use memory mapped I/O devices. `set remotecache
5844 off' turns the the data cache off.
5846 * Remote targets may have threads
5848 The standard remote protocol now includes support for multiple threads
5849 in the target system, using new protocol commands 'H' and 'T'. See
5850 gdb/remote.c for details.
5854 If GDB is configured with `--enable-netrom', then it will include
5855 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5856 acts as though it is a bank of ROM on the target board, but you can
5857 write into it over the network. GDB's support consists only of
5858 support for fast loading into the emulated ROM; to debug, you must use
5859 another protocol, such as standard remote protocol. The usual
5860 sequence is something like
5862 target nrom <netrom-hostname>
5864 target remote <netrom-hostname>:1235
5868 GDB now includes support for the Apple Macintosh, as a host only. It
5869 may be run as either an MPW tool or as a standalone application, and
5870 it can debug through the serial port. All the usual GDB commands are
5871 available, but to the target command, you must supply "serial" as the
5872 device type instead of "/dev/ttyXX". See mpw-README in the main
5873 directory for more information on how to build. The MPW configuration
5874 scripts */mpw-config.in support only a few targets, and only the
5875 mips-idt-ecoff target has been tested.
5879 GDB configuration now uses autoconf. This is not user-visible,
5880 but does simplify configuration and building.
5884 GDB now supports hpux10.
5886 *** Changes in GDB-4.14:
5888 * New native configurations
5890 x86 FreeBSD i[345]86-*-freebsd
5891 x86 NetBSD i[345]86-*-netbsd
5892 NS32k NetBSD ns32k-*-netbsd
5893 Sparc NetBSD sparc-*-netbsd
5897 A29K VxWorks a29k-*-vxworks
5898 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5899 CPU32 EST-300 emulator m68*-*-est*
5900 PowerPC ELF powerpc-*-elf
5903 * Alpha OSF/1 support for procfs
5905 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5906 possible to attach to running processes. As the mounting of the /proc
5907 filesystem is optional on the Alpha, GDB automatically determines
5908 the availability of /proc during startup. This can lead to problems
5909 if /proc is unmounted after GDB has been started.
5911 * Arguments to user-defined commands
5913 User commands may accept up to 10 arguments separated by whitespace.
5914 Arguments are accessed within the user command via $arg0..$arg9. A
5917 print $arg0 + $arg1 + $arg2
5919 To execute the command use:
5922 Defines the command "adder" which prints the sum of its three arguments.
5923 Note the arguments are text substitutions, so they may reference variables,
5924 use complex expressions, or even perform inferior function calls.
5926 * New `if' and `while' commands
5928 This makes it possible to write more sophisticated user-defined
5929 commands. Both commands take a single argument, which is the
5930 expression to evaluate, and must be followed by the commands to
5931 execute, one per line, if the expression is nonzero, the list being
5932 terminated by the word `end'. The `if' command list may include an
5933 `else' word, which causes the following commands to be executed only
5934 if the expression is zero.
5936 * Fortran source language mode
5938 GDB now includes partial support for Fortran 77. It will recognize
5939 Fortran programs and can evaluate a subset of Fortran expressions, but
5940 variables and functions may not be handled correctly. GDB will work
5941 with G77, but does not yet know much about symbols emitted by other
5944 * Better HPUX support
5946 Most debugging facilities now work on dynamic executables for HPPAs
5947 running hpux9 or later. You can attach to running dynamically linked
5948 processes, but by default the dynamic libraries will be read-only, so
5949 for instance you won't be able to put breakpoints in them. To change
5950 that behavior do the following before running the program:
5956 This will cause the libraries to be mapped private and read-write.
5957 To revert to the normal behavior, do this:
5963 You cannot set breakpoints or examine data in the library until after
5964 the library is loaded if the function/data symbols do not have
5967 GDB can now also read debug symbols produced by the HP C compiler on
5968 HPPAs (sorry, no C++, Fortran or 68k support).
5970 * Target byte order now dynamically selectable
5972 You can choose which byte order to use with a target system, via the
5973 commands "set endian big" and "set endian little", and you can see the
5974 current setting by using "show endian". You can also give the command
5975 "set endian auto", in which case GDB will use the byte order
5976 associated with the executable. Currently, only embedded MIPS
5977 configurations support dynamic selection of target byte order.
5979 * New DOS host serial code
5981 This version uses DPMI interrupts to handle buffered I/O, so you
5982 no longer need to run asynctsr when debugging boards connected to
5985 *** Changes in GDB-4.13:
5987 * New "complete" command
5989 This lists all the possible completions for the rest of the line, if it
5990 were to be given as a command itself. This is intended for use by emacs.
5992 * Trailing space optional in prompt
5994 "set prompt" no longer adds a space for you after the prompt you set. This
5995 allows you to set a prompt which ends in a space or one that does not.
5997 * Breakpoint hit counts
5999 "info break" now displays a count of the number of times the breakpoint
6000 has been hit. This is especially useful in conjunction with "ignore"; you
6001 can ignore a large number of breakpoint hits, look at the breakpoint info
6002 to see how many times the breakpoint was hit, then run again, ignoring one
6003 less than that number, and this will get you quickly to the last hit of
6006 * Ability to stop printing at NULL character
6008 "set print null-stop" will cause GDB to stop printing the characters of
6009 an array when the first NULL is encountered. This is useful when large
6010 arrays actually contain only short strings.
6012 * Shared library breakpoints
6014 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6015 breakpoints in shared libraries before the executable is run.
6017 * Hardware watchpoints
6019 There is a new hardware breakpoint for the watch command for sparclite
6020 targets. See gdb/sparclite/hw_breakpoint.note.
6022 Hardware watchpoints are also now supported under GNU/Linux.
6026 Annotations have been added. These are for use with graphical interfaces,
6027 and are still experimental. Currently only gdba.el uses these.
6029 * Improved Irix 5 support
6031 GDB now works properly with Irix 5.2.
6033 * Improved HPPA support
6035 GDB now works properly with the latest GCC and GAS.
6037 * New native configurations
6039 Sequent PTX4 i[34]86-sequent-ptx4
6040 HPPA running OSF/1 hppa*-*-osf*
6041 Atari TT running SVR4 m68*-*-sysv4*
6042 RS/6000 LynxOS rs6000-*-lynxos*
6046 OS/9000 i[34]86-*-os9k
6047 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6050 * Hitachi SH7000 and E7000-PC ICE support
6052 There is now support for communicating with the Hitachi E7000-PC ICE.
6053 This is available automatically when GDB is configured for the SH.
6057 As usual, a variety of small fixes and improvements, both generic
6058 and configuration-specific. See the ChangeLog for more detail.
6060 *** Changes in GDB-4.12:
6062 * Irix 5 is now supported
6066 GDB-4.12 on the HPPA has a number of changes which make it unable
6067 to debug the output from the currently released versions of GCC and
6068 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6069 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6070 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6073 *** Changes in GDB-4.11:
6075 * User visible changes:
6079 The "set remotedebug" option is now consistent between the mips remote
6080 target, remote targets using the gdb-specific protocol, UDI (AMD's
6081 debug protocol for the 29k) and the 88k bug monitor. It is now an
6082 integer specifying a debug level (normally 0 or 1, but 2 means more
6083 debugging info for the mips target).
6085 * DEC Alpha native support
6087 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6088 debug info, but GDB works fairly well with the DEC compiler and should
6089 work with a future GCC release. See the README file for a few
6090 Alpha-specific notes.
6092 * Preliminary thread implementation
6094 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6096 * LynxOS native and target support for 386
6098 This release has been hosted on LynxOS 2.2, and also can be configured
6099 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6102 * Improvements in C++ mangling/demangling.
6104 This release has much better g++ debugging, specifically in name
6105 mangling/demangling, virtual function calls, print virtual table,
6106 call methods, ...etc.
6108 *** Changes in GDB-4.10:
6110 * User visible changes:
6112 Remote debugging using the GDB-specific (`target remote') protocol now
6113 supports the `load' command. This is only useful if you have some
6114 other way of getting the stub to the target system, and you can put it
6115 somewhere in memory where it won't get clobbered by the download.
6117 Filename completion now works.
6119 When run under emacs mode, the "info line" command now causes the
6120 arrow to point to the line specified. Also, "info line" prints
6121 addresses in symbolic form (as well as hex).
6123 All vxworks based targets now support a user settable option, called
6124 vxworks-timeout. This option represents the number of seconds gdb
6125 should wait for responses to rpc's. You might want to use this if
6126 your vxworks target is, perhaps, a slow software simulator or happens
6127 to be on the far side of a thin network line.
6131 This release contains support for using a DEC alpha as a GDB host for
6132 cross debugging. Native alpha debugging is not supported yet.
6135 *** Changes in GDB-4.9:
6139 This is the first GDB release which is accompanied by a matching testsuite.
6140 The testsuite requires installation of dejagnu, which should be available
6141 via ftp from most sites that carry GNU software.
6145 'Cfront' style demangling has had its name changed to 'ARM' style, to
6146 emphasize that it was written from the specifications in the C++ Annotated
6147 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6148 disclaimers, it still generated too much confusion with users attempting to
6149 use gdb with AT&T cfront.
6153 GDB now uses a standard remote interface to a simulator library.
6154 So far, the library contains simulators for the Zilog Z8001/2, the
6155 Hitachi H8/300, H8/500 and Super-H.
6157 * New targets supported
6159 H8/300 simulator h8300-hitachi-hms or h8300hms
6160 H8/500 simulator h8500-hitachi-hms or h8500hms
6161 SH simulator sh-hitachi-hms or sh
6162 Z8000 simulator z8k-zilog-none or z8ksim
6163 IDT MIPS board over serial line mips-idt-ecoff
6165 Cross-debugging to GO32 targets is supported. It requires a custom
6166 version of the i386-stub.c module which is integrated with the
6167 GO32 memory extender.
6169 * New remote protocols
6171 MIPS remote debugging protocol.
6173 * New source languages supported
6175 This version includes preliminary support for Chill, a Pascal like language
6176 used by telecommunications companies. Chill support is also being integrated
6177 into the GNU compiler, but we don't know when it will be publically available.
6180 *** Changes in GDB-4.8:
6182 * HP Precision Architecture supported
6184 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6185 version of this support was available as a set of patches from the
6186 University of Utah. GDB does not support debugging of programs
6187 compiled with the HP compiler, because HP will not document their file
6188 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6189 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6191 Many problems in the preliminary version have been fixed.
6193 * Faster and better demangling
6195 We have improved template demangling and fixed numerous bugs in the GNU style
6196 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6197 character types (wchar_t) are now supported. Demangling of each symbol is now
6198 only done once, and is cached when the symbol table for a file is read in.
6199 This results in a small increase in memory usage for C programs, a moderate
6200 increase in memory usage for C++ programs, and a fantastic speedup in
6203 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6204 from the specifications in the Annotated Reference Manual, which AT&T's
6205 compiler does not actually implement.
6207 * G++ multiple inheritance compiler problem
6209 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6210 inheritance lattices was reworked to properly discover ambiguities. We
6211 recently found an example which causes this new algorithm to fail in a
6212 very subtle way, producing bad debug information for those classes.
6213 The file 'gcc.patch' (in this directory) can be applied to gcc to
6214 circumvent the problem. A future GCC release will contain a complete
6217 The previous G++ debug info problem (mentioned below for the gdb-4.7
6218 release) is fixed in gcc version 2.3.2.
6220 * Improved configure script
6222 The `configure' script will now attempt to guess your system type if
6223 you don't supply a host system type. The old scheme of supplying a
6224 host system triplet is preferable over using this. All the magic is
6225 done in the new `config.guess' script. Examine it for details.
6227 We have also brought our configure script much more in line with the FSF's
6228 version. It now supports the --with-xxx options. In particular,
6229 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6230 The resulting GDB will not be able to read arbitrary object file formats --
6231 only the format ``expected'' to be used on the configured target system.
6232 We hope to make this the default in a future release.
6234 * Documentation improvements
6236 There's new internal documentation on how to modify GDB, and how to
6237 produce clean changes to the code. We implore people to read it
6238 before submitting changes.
6240 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6241 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6242 `info' files are also provided. To build `info' files from scratch,
6243 you will need the latest `makeinfo' release, which will be available in
6244 a future texinfo-X.Y release.
6246 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6247 We're not sure exactly which versions have this problem, but it has
6248 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6249 or better. If that isn't possible, there is a patch in
6250 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6251 around this problem.
6255 GDB now supports array constants that can be used in expressions typed in by
6256 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6257 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6260 The new directory `gdb/sparclite' contains a program that demonstrates
6261 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6263 * New native hosts supported
6265 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6266 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6268 * New targets supported
6270 AMD 29k family via UDI a29k-amd-udi or udi29k
6272 * New file formats supported
6274 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6275 HPUX core files, and SCO 3.2v2 core files.
6279 Attaching to processes now works again; thanks for the many bug reports.
6281 We have also stomped on a bunch of core dumps caused by
6282 printf_filtered("%s") problems.
6284 We eliminated a copyright problem on the rpc and ptrace header files
6285 for VxWorks, which was discovered at the last minute during the 4.7
6286 release. You should now be able to build a VxWorks GDB.
6288 You can now interrupt gdb while an attached process is running. This
6289 will cause the attached process to stop, and give control back to GDB.
6291 We fixed problems caused by using too many file descriptors
6292 for reading symbols from object files and libraries. This was
6293 especially a problem for programs that used many (~100) shared
6296 The `step' command now only enters a subroutine if there is line number
6297 information for the subroutine. Otherwise it acts like the `next'
6298 command. Previously, `step' would enter subroutines if there was
6299 any debugging information about the routine. This avoids problems
6300 when using `cc -g1' on MIPS machines.
6302 * Internal improvements
6304 GDB's internal interfaces have been improved to make it easier to support
6305 debugging of multiple languages in the future.
6307 GDB now uses a common structure for symbol information internally.
6308 Minimal symbols (derived from linkage symbols in object files), partial
6309 symbols (from a quick scan of debug information), and full symbols
6310 contain a common subset of information, making it easier to write
6311 shared code that handles any of them.
6313 * New command line options
6315 We now accept --silent as an alias for --quiet.
6319 The memory-mapped-malloc library is now licensed under the GNU Library
6320 General Public License.
6322 *** Changes in GDB-4.7:
6324 * Host/native/target split
6326 GDB has had some major internal surgery to untangle the support for
6327 hosts and remote targets. Now, when you configure GDB for a remote
6328 target, it will no longer load in all of the support for debugging
6329 local programs on the host. When fully completed and tested, this will
6330 ensure that arbitrary host/target combinations are possible.
6332 The primary conceptual shift is to separate the non-portable code in
6333 GDB into three categories. Host specific code is required any time GDB
6334 is compiled on that host, regardless of the target. Target specific
6335 code relates to the peculiarities of the target, but can be compiled on
6336 any host. Native specific code is everything else: it can only be
6337 built when the host and target are the same system. Child process
6338 handling and core file support are two common `native' examples.
6340 GDB's use of /proc for controlling Unix child processes is now cleaner.
6341 It has been split out into a single module under the `target_ops' vector,
6342 plus two native-dependent functions for each system that uses /proc.
6344 * New hosts supported
6346 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6347 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6348 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6350 * New targets supported
6352 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6353 68030 and CPU32 m68030-*-*, m68332-*-*
6355 * New native hosts supported
6357 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6358 (386bsd is not well tested yet)
6359 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6361 * New file formats supported
6363 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6364 supports reading of `a.out.adobe' object files, which are an a.out
6365 format extended with minimal information about multiple sections.
6369 `show copying' is the same as the old `info copying'.
6370 `show warranty' is the same as `info warrantee'.
6371 These were renamed for consistency. The old commands continue to work.
6373 `info handle' is a new alias for `info signals'.
6375 You can now define pre-command hooks, which attach arbitrary command
6376 scripts to any command. The commands in the hook will be executed
6377 prior to the user's command. You can also create a hook which will be
6378 executed whenever the program stops. See gdb.texinfo.
6382 We now deal with Cfront style name mangling, and can even extract type
6383 info from mangled symbols. GDB can automatically figure out which
6384 symbol mangling style your C++ compiler uses.
6386 Calling of methods and virtual functions has been improved as well.
6390 The crash that occured when debugging Sun Ansi-C compiled binaries is
6391 fixed. This was due to mishandling of the extra N_SO stabs output
6394 We also finally got Ultrix 4.2 running in house, and fixed core file
6395 support, with help from a dozen people on the net.
6397 John M. Farrell discovered that the reason that single-stepping was so
6398 slow on all of the Mips based platforms (primarily SGI and DEC) was
6399 that we were trying to demangle and lookup a symbol used for internal
6400 purposes on every instruction that was being stepped through. Changing
6401 the name of that symbol so that it couldn't be mistaken for a C++
6402 mangled symbol sped things up a great deal.
6404 Rich Pixley sped up symbol lookups in general by getting much smarter
6405 about when C++ symbol mangling is necessary. This should make symbol
6406 completion (TAB on the command line) much faster. It's not as fast as
6407 we'd like, but it's significantly faster than gdb-4.6.
6411 A new user controllable variable 'call_scratch_address' can
6412 specify the location of a scratch area to be used when GDB
6413 calls a function in the target. This is necessary because the
6414 usual method of putting the scratch area on the stack does not work
6415 in systems that have separate instruction and data spaces.
6417 We integrated changes to support the 29k UDI (Universal Debugger
6418 Interface), but discovered at the last minute that we didn't have all
6419 of the appropriate copyright paperwork. We are working with AMD to
6420 resolve this, and hope to have it available soon.
6424 We have sped up the remote serial line protocol, especially for targets
6425 with lots of registers. It now supports a new `expedited status' ('T')
6426 message which can be used in place of the existing 'S' status message.
6427 This allows the remote stub to send only the registers that GDB
6428 needs to make a quick decision about single-stepping or conditional
6429 breakpoints, eliminating the need to fetch the entire register set for
6430 each instruction being stepped through.
6432 The GDB remote serial protocol now implements a write-through cache for
6433 registers, only re-reading the registers if the target has run.
6435 There is also a new remote serial stub for SPARC processors. You can
6436 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6437 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6438 processor with a serial port.
6442 Configure.in files have become much easier to read and modify. A new
6443 `table driven' format makes it more obvious what configurations are
6444 supported, and what files each one uses.
6448 There is a new opcodes library which will eventually contain all of the
6449 disassembly routines and opcode tables. At present, it only contains
6450 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6451 disassembler (binutils/objdump) to share these routines.
6453 The libiberty library is now copylefted under the GNU Library General
6454 Public License. This allows more liberal use, and was done so libg++
6455 can use it. This makes no difference to GDB, since the Library License
6456 grants all the rights from the General Public License.
6460 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6461 reference to the stabs symbol info used by the debugger. It is (as far
6462 as we know) the only published document on this fascinating topic. We
6463 encourage you to read it, compare it to the stabs information on your
6464 system, and send improvements on the document in general (to
6465 bug-gdb@prep.ai.mit.edu).
6467 And, of course, many bugs have been fixed.
6470 *** Changes in GDB-4.6:
6472 * Better support for C++ function names
6474 GDB now accepts as input the "demangled form" of C++ overloaded function
6475 names and member function names, and can do command completion on such names
6476 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6477 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6478 Make use of command completion, it is your friend.
6480 GDB also now accepts a variety of C++ mangled symbol formats. They are
6481 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6482 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6483 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6484 for the list of formats.
6486 * G++ symbol mangling problem
6488 Recent versions of gcc have a bug in how they emit debugging information for
6489 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6490 directory) can be applied to gcc to fix the problem. Alternatively, if you
6491 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6492 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6493 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6496 * New 'maintenance' command
6498 All of the commands related to hacking GDB internals have been moved out of
6499 the main command set, and now live behind the 'maintenance' command. This
6500 can also be abbreviated as 'mt'. The following changes were made:
6502 dump-me -> maintenance dump-me
6503 info all-breakpoints -> maintenance info breakpoints
6504 printmsyms -> maintenance print msyms
6505 printobjfiles -> maintenance print objfiles
6506 printpsyms -> maintenance print psymbols
6507 printsyms -> maintenance print symbols
6509 The following commands are new:
6511 maintenance demangle Call internal GDB demangler routine to
6512 demangle a C++ link name and prints the result.
6513 maintenance print type Print a type chain for a given symbol
6515 * Change to .gdbinit file processing
6517 We now read the $HOME/.gdbinit file before processing the argv arguments
6518 (e.g. reading symbol files or core files). This allows global parameters to
6519 be set, which will apply during the symbol reading. The ./.gdbinit is still
6520 read after argv processing.
6522 * New hosts supported
6524 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6526 GNU/Linux support i386-unknown-linux or linux
6528 We are also including code to support the HP/PA running BSD and HPUX. This
6529 is almost guaranteed not to work, as we didn't have time to test or build it
6530 for this release. We are including it so that the more adventurous (or
6531 masochistic) of you can play with it. We also had major problems with the
6532 fact that the compiler that we got from HP doesn't support the -g option.
6535 * New targets supported
6537 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6539 * More smarts about finding #include files
6541 GDB now remembers the compilation directory for all include files, and for
6542 all files from which C is generated (like yacc and lex sources). This
6543 greatly improves GDB's ability to find yacc/lex sources, and include files,
6544 especially if you are debugging your program from a directory different from
6545 the one that contains your sources.
6547 We also fixed a bug which caused difficulty with listing and setting
6548 breakpoints in include files which contain C code. (In the past, you had to
6549 try twice in order to list an include file that you hadn't looked at before.)
6551 * Interesting infernals change
6553 GDB now deals with arbitrary numbers of sections, where the symbols for each
6554 section must be relocated relative to that section's landing place in the
6555 target's address space. This work was needed to support ELF with embedded
6556 stabs used by Solaris-2.0.
6558 * Bug fixes (of course!)
6560 There have been loads of fixes for the following things:
6561 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6562 i960, stabs, DOS(GO32), procfs, etc...
6564 See the ChangeLog for details.
6566 *** Changes in GDB-4.5:
6568 * New machines supported (host and target)
6570 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6572 SGI Irix-4.x mips-sgi-irix4 or iris4
6574 * New malloc package
6576 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6577 Mmalloc is capable of handling mutiple heaps of memory. It is also
6578 capable of saving a heap to a file, and then mapping it back in later.
6579 This can be used to greatly speedup the startup of GDB by using a
6580 pre-parsed symbol table which lives in a mmalloc managed heap. For
6581 more details, please read mmalloc/mmalloc.texi.
6585 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6586 'help info proc' for details.
6588 * MIPS ecoff symbol table format
6590 The code that reads MIPS symbol table format is now supported on all hosts.
6591 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6594 * File name changes for MS-DOS
6596 Many files in the config directories have been renamed to make it easier to
6597 support GDB on MS-DOSe systems (which have very restrictive file name
6598 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6599 environment) is close to working but has some remaining problems. Note
6600 that debugging of DOS programs is not supported, due to limitations
6601 in the ``operating system'', but it can be used to host cross-debugging.
6603 * Cross byte order fixes
6605 Many fixes have been made to support cross debugging of Sparc and MIPS
6606 targets from hosts whose byte order differs.
6608 * New -mapped and -readnow options
6610 If memory-mapped files are available on your system through the 'mmap'
6611 system call, you can use the -mapped option on the `file' or
6612 `symbol-file' commands to cause GDB to write the symbols from your
6613 program into a reusable file. If the program you are debugging is
6614 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6615 Future GDB debugging sessions will notice the presence of this file,
6616 and will quickly map in symbol information from it, rather than reading
6617 the symbol table from the executable program. Using the '-mapped'
6618 option in a GDB `file' or `symbol-file' command has the same effect as
6619 starting GDB with the '-mapped' command-line option.
6621 You can cause GDB to read the entire symbol table immediately by using
6622 the '-readnow' option with any of the commands that load symbol table
6623 information (or on the GDB command line). This makes the command
6624 slower, but makes future operations faster.
6626 The -mapped and -readnow options are typically combined in order to
6627 build a `fred.syms' file that contains complete symbol information.
6628 A simple GDB invocation to do nothing but build a `.syms' file for future
6631 gdb -batch -nx -mapped -readnow programname
6633 The `.syms' file is specific to the host machine on which GDB is run.
6634 It holds an exact image of GDB's internal symbol table. It cannot be
6635 shared across multiple host platforms.
6637 * longjmp() handling
6639 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6640 siglongjmp() without losing control. This feature has not yet been ported to
6641 all systems. It currently works on many 386 platforms, all MIPS-based
6642 platforms (SGI, DECstation, etc), and Sun3/4.
6646 Preliminary work has been put in to support the new Solaris OS from Sun. At
6647 this time, it can control and debug processes, but it is not capable of
6652 As always, many many bug fixes. The major areas were with g++, and mipsread.
6653 People using the MIPS-based platforms should experience fewer mysterious
6654 crashes and trashed symbol tables.
6656 *** Changes in GDB-4.4:
6658 * New machines supported (host and target)
6660 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6662 BSD Reno on Vax vax-dec-bsd
6663 Ultrix on Vax vax-dec-ultrix
6665 * New machines supported (target)
6667 AMD 29000 embedded, using EBMON a29k-none-none
6671 GDB continues to improve its handling of C++. `References' work better.
6672 The demangler has also been improved, and now deals with symbols mangled as
6673 per the Annotated C++ Reference Guide.
6675 GDB also now handles `stabs' symbol information embedded in MIPS
6676 `ecoff' symbol tables. Since the ecoff format was not easily
6677 extensible to handle new languages such as C++, this appeared to be a
6678 good way to put C++ debugging info into MIPS binaries. This option
6679 will be supported in the GNU C compiler, version 2, when it is
6682 * New features for SVR4
6684 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6685 shared libraries. Debugging dynamically linked programs should present
6686 only minor differences from debugging statically linked programs.
6688 The `info proc' command will print out information about any process
6689 on an SVR4 system (including the one you are debugging). At the moment,
6690 it prints the address mappings of the process.
6692 If you bring up GDB on another SVR4 system, please send mail to
6693 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6695 * Better dynamic linking support in SunOS
6697 Reading symbols from shared libraries which contain debugging symbols
6698 now works properly. However, there remain issues such as automatic
6699 skipping of `transfer vector' code during function calls, which
6700 make it harder to debug code in a shared library, than to debug the
6701 same code linked statically.
6705 GDB is now using the latest `getopt' routines from the FSF. This
6706 version accepts the -- prefix for options with long names. GDB will
6707 continue to accept the old forms (-option and +option) as well.
6708 Various single letter abbreviations for options have been explicity
6709 added to the option table so that they won't get overshadowed in the
6710 future by other options that begin with the same letter.
6714 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6715 Many assorted bugs have been handled. Many more remain to be handled.
6716 See the various ChangeLog files (primarily in gdb and bfd) for details.
6719 *** Changes in GDB-4.3:
6721 * New machines supported (host and target)
6723 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6724 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6725 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6727 * Almost SCO Unix support
6729 We had hoped to support:
6730 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6731 (except for core file support), but we discovered very late in the release
6732 that it has problems with process groups that render gdb unusable. Sorry
6733 about that. I encourage people to fix it and post the fixes.
6735 * Preliminary ELF and DWARF support
6737 GDB can read ELF object files on System V Release 4, and can handle
6738 debugging records for C, in DWARF format, in ELF files. This support
6739 is preliminary. If you bring up GDB on another SVR4 system, please
6740 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6745 GDB now uses the latest `readline' library. One user-visible change
6746 is that two tabs will list possible command completions, which previously
6747 required typing M-? (meta-question mark, or ESC ?).
6751 The `stepi' bug that many of you noticed has been squashed.
6752 Many bugs in C++ have been handled. Many more remain to be handled.
6753 See the various ChangeLog files (primarily in gdb and bfd) for details.
6755 * State of the MIPS world (in case you wondered):
6757 GDB can understand the symbol tables emitted by the compilers
6758 supplied by most vendors of MIPS-based machines, including DEC. These
6759 symbol tables are in a format that essentially nobody else uses.
6761 Some versions of gcc come with an assembler post-processor called
6762 mips-tfile. This program is required if you want to do source-level
6763 debugging of gcc-compiled programs. I believe FSF does not ship
6764 mips-tfile with gcc version 1, but it will eventually come with gcc
6767 Debugging of g++ output remains a problem. g++ version 1.xx does not
6768 really support it at all. (If you're lucky, you should be able to get
6769 line numbers and stack traces to work, but no parameters or local
6770 variables.) With some work it should be possible to improve the
6773 When gcc version 2 is released, you will have somewhat better luck.
6774 However, even then you will get confusing results for inheritance and
6777 We will eventually provide full debugging of g++ output on
6778 DECstations. This will probably involve some kind of stabs-in-ecoff
6779 encapulation, but the details have not been worked out yet.
6782 *** Changes in GDB-4.2:
6784 * Improved configuration
6786 Only one copy of `configure' exists now, and it is not self-modifying.
6787 Porting BFD is simpler.
6791 The `step' and `next' commands now only stop at the first instruction
6792 of a source line. This prevents the multiple stops that used to occur
6793 in switch statements, for-loops, etc. `Step' continues to stop if a
6794 function that has debugging information is called within the line.
6798 Lots of small bugs fixed. More remain.
6800 * New host supported (not target)
6802 Intel 386 PC clone running Mach i386-none-mach
6805 *** Changes in GDB-4.1:
6807 * Multiple source language support
6809 GDB now has internal scaffolding to handle several source languages.
6810 It determines the type of each source file from its filename extension,
6811 and will switch expression parsing and number formatting to match the
6812 language of the function in the currently selected stack frame.
6813 You can also specifically set the language to be used, with
6814 `set language c' or `set language modula-2'.
6818 GDB now has preliminary support for the GNU Modula-2 compiler,
6819 currently under development at the State University of New York at
6820 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6821 continue through the fall of 1991 and into 1992.
6823 Other Modula-2 compilers are currently not supported, and attempting to
6824 debug programs compiled with them will likely result in an error as the
6825 symbol table is read. Feel free to work on it, though!
6827 There are hooks in GDB for strict type checking and range checking,
6828 in the `Modula-2 philosophy', but they do not currently work.
6832 GDB can now write to executable and core files (e.g. patch
6833 a variable's value). You must turn this switch on, specify
6834 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6835 by assigning a new value to a variable. Modifications take
6838 * Automatic SunOS shared library reading
6840 When you run your program, GDB automatically determines where its
6841 shared libraries (if any) have been loaded, and reads their symbols.
6842 The `share' command is no longer needed. This also works when
6843 examining core files.
6847 You can specify the number of lines that the `list' command shows.
6850 * New machines supported (host and target)
6852 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6853 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6854 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6856 * New hosts supported (not targets)
6858 IBM RT/PC: romp-ibm-aix or rtpc
6860 * New targets supported (not hosts)
6862 AMD 29000 embedded with COFF a29k-none-coff
6863 AMD 29000 embedded with a.out a29k-none-aout
6864 Ultracomputer remote kernel debug a29k-nyu-kern
6866 * New remote interfaces
6872 *** Changes in GDB-4.0:
6876 Wide output is wrapped at good places to make the output more readable.
6878 Gdb now supports cross-debugging from a host machine of one type to a
6879 target machine of another type. Communication with the target system
6880 is over serial lines. The ``target'' command handles connecting to the
6881 remote system; the ``load'' command will download a program into the
6882 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6883 also supports debugging of realtime processes running under VxWorks,
6884 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6885 stub on the target system.
6887 New CPUs supported include the AMD 29000 and Intel 960.
6889 GDB now reads object files and symbol tables via a ``binary file''
6890 library, which allows a single copy of GDB to debug programs of multiple
6891 object file types such as a.out and coff.
6893 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6894 refcard.dvi and refcard.ps are available to format it).
6897 * Control-Variable user interface simplified
6899 All variables that control the operation of the debugger can be set
6900 by the ``set'' command, and displayed by the ``show'' command.
6902 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6903 ``Show prompt'' produces the response:
6904 Gdb's prompt is new-gdb=>.
6906 What follows are the NEW set commands. The command ``help set'' will
6907 print a complete list of old and new set commands. ``help set FOO''
6908 will give a longer description of the variable FOO. ``show'' will show
6909 all of the variable descriptions and their current settings.
6911 confirm on/off: Enables warning questions for operations that are
6912 hard to recover from, e.g. rerunning the program while
6913 it is already running. Default is ON.
6915 editing on/off: Enables EMACS style command line editing
6916 of input. Previous lines can be recalled with
6917 control-P, the current line can be edited with control-B,
6918 you can search for commands with control-R, etc.
6921 history filename NAME: NAME is where the gdb command history
6922 will be stored. The default is .gdb_history,
6923 or the value of the environment variable
6926 history size N: The size, in commands, of the command history. The
6927 default is 256, or the value of the environment variable
6930 history save on/off: If this value is set to ON, the history file will
6931 be saved after exiting gdb. If set to OFF, the
6932 file will not be saved. The default is OFF.
6934 history expansion on/off: If this value is set to ON, then csh-like
6935 history expansion will be performed on
6936 command line input. The default is OFF.
6938 radix N: Sets the default radix for input and output. It can be set
6939 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6940 in the current radix, so "set radix 10" is always a no-op.
6942 height N: This integer value is the number of lines on a page. Default
6943 is 24, the current `stty rows'' setting, or the ``li#''
6944 setting from the termcap entry matching the environment
6947 width N: This integer value is the number of characters on a line.
6948 Default is 80, the current `stty cols'' setting, or the ``co#''
6949 setting from the termcap entry matching the environment
6952 Note: ``set screensize'' is obsolete. Use ``set height'' and
6953 ``set width'' instead.
6955 print address on/off: Print memory addresses in various command displays,
6956 such as stack traces and structure values. Gdb looks
6957 more ``symbolic'' if you turn this off; it looks more
6958 ``machine level'' with it on. Default is ON.
6960 print array on/off: Prettyprint arrays. New convenient format! Default
6963 print demangle on/off: Print C++ symbols in "source" form if on,
6966 print asm-demangle on/off: Same, for assembler level printouts
6969 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6972 * Support for Epoch Environment.
6974 The epoch environment is a version of Emacs v18 with windowing. One
6975 new command, ``inspect'', is identical to ``print'', except that if you
6976 are running in the epoch environment, the value is printed in its own
6980 * Support for Shared Libraries
6982 GDB can now debug programs and core files that use SunOS shared libraries.
6983 Symbols from a shared library cannot be referenced
6984 before the shared library has been linked with the program (this
6985 happens after you type ``run'' and before the function main() is entered).
6986 At any time after this linking (including when examining core files
6987 from dynamically linked programs), gdb reads the symbols from each
6988 shared library when you type the ``sharedlibrary'' command.
6989 It can be abbreviated ``share''.
6991 sharedlibrary REGEXP: Load shared object library symbols for files
6992 matching a unix regular expression. No argument
6993 indicates to load symbols for all shared libraries.
6995 info sharedlibrary: Status of loaded shared libraries.
7000 A watchpoint stops execution of a program whenever the value of an
7001 expression changes. Checking for this slows down execution
7002 tremendously whenever you are in the scope of the expression, but is
7003 quite useful for catching tough ``bit-spreader'' or pointer misuse
7004 problems. Some machines such as the 386 have hardware for doing this
7005 more quickly, and future versions of gdb will use this hardware.
7007 watch EXP: Set a watchpoint (breakpoint) for an expression.
7009 info watchpoints: Information about your watchpoints.
7011 delete N: Deletes watchpoint number N (same as breakpoints).
7012 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7013 enable N: Re-enables watchpoint number N (same as breakpoints).
7016 * C++ multiple inheritance
7018 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7021 * C++ exception handling
7023 Gdb now supports limited C++ exception handling. Besides the existing
7024 ability to breakpoint on an exception handler, gdb can breakpoint on
7025 the raising of an exception (before the stack is peeled back to the
7028 catch FOO: If there is a FOO exception handler in the dynamic scope,
7029 set a breakpoint to catch exceptions which may be raised there.
7030 Multiple exceptions (``catch foo bar baz'') may be caught.
7032 info catch: Lists all exceptions which may be caught in the
7033 current stack frame.
7036 * Minor command changes
7038 The command ``call func (arg, arg, ...)'' now acts like the print
7039 command, except it does not print or save a value if the function's result
7040 is void. This is similar to dbx usage.
7042 The ``up'' and ``down'' commands now always print the frame they end up
7043 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7044 frames without printing.
7046 * New directory command
7048 'dir' now adds directories to the FRONT of the source search path.
7049 The path starts off empty. Source files that contain debug information
7050 about the directory in which they were compiled can be found even
7051 with an empty path; Sun CC and GCC include this information. If GDB can't
7052 find your source file in the current directory, type "dir .".
7054 * Configuring GDB for compilation
7056 For normal use, type ``./configure host''. See README or gdb.texinfo
7059 GDB now handles cross debugging. If you are remotely debugging between
7060 two different machines, type ``./configure host -target=targ''.
7061 Host is the machine where GDB will run; targ is the machine
7062 where the program that you are debugging will run.