1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
6 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
7 can be passed using the '[ADDRESS]:PORT' notation, or the regular
12 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
13 Apply a command to some frames.
14 FLAG arguments allow to control what output to produce and how to handle
15 errors raised when applying COMMAND to a frame.
18 Apply a command to all threads (ignoring errors and empty output).
19 Shortcut for 'thread apply all -s COMMAND'.
22 Apply a command to all frames (ignoring errors and empty output).
23 Shortcut for 'frame apply all -s COMMAND'.
26 Apply a command to all frames of all threads (ignoring errors and empty
28 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
30 maint set dwarf unwinders (on|off)
31 maint show dwarf unwinders
32 Control whether DWARF unwinders can be used.
36 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
37 The 'thread apply' command accepts new FLAG arguments.
38 FLAG arguments allow to control what output to produce and how to handle
39 errors raised when applying COMMAND to a thread.
41 *** Changes in GDB 8.2
43 * The 'set disassembler-options' command now supports specifying options
46 * The 'symbol-file' command now accepts an '-o' option to add a relative
47 offset to all sections.
49 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
50 a relative offset to all sections, but it allows to override the load
51 address of individual sections using '-s'.
53 * The 'add-symbol-file' command no longer requires the second argument
54 (address of the text section).
56 * The endianness used with the 'set endian auto' mode in the absence of
57 an executable selected for debugging is now the last endianness chosen
58 either by one of the 'set endian big' and 'set endian little' commands
59 or by inferring from the last executable used, rather than the startup
62 * The pager now allows a "c" response, meaning to disable the pager
63 for the rest of the current command.
65 * The commands 'info variables/functions/types' now show the source line
66 numbers of symbol definitions when available.
68 * 'info proc' now works on running processes on FreeBSD systems and core
69 files created on FreeBSD systems.
71 * C expressions can now use _Alignof, and C++ expressions can now use
78 Control display of debugging info regarding the FreeBSD native target.
80 set|show varsize-limit
81 This new setting allows the user to control the maximum size of Ada
82 objects being printed when those objects have a variable type,
83 instead of that maximum size being hardcoded to 65536 bytes.
85 set|show record btrace cpu
86 Controls the processor to be used for enabling errata workarounds for
89 maint check libthread-db
90 Run integrity checks on the current inferior's thread debugging
93 maint set check-libthread-db (on|off)
94 maint show check-libthread-db
95 Control whether to run integrity checks on inferior specific thread
96 debugging libraries as they are loaded. The default is not to
101 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
103 ** The commands attached to a breakpoint can be set by assigning to
104 the breakpoint's "commands" field.
106 ** gdb.execute can now execute multi-line gdb commands.
108 ** The new functions gdb.convenience_variable and
109 gdb.set_convenience_variable can be used to get and set the value
110 of convenience variables.
112 ** A gdb.Parameter will no longer print the "set" help text on an
113 ordinary "set"; instead by default a "set" will be silent unless
114 the get_set_string method returns a non-empty string.
118 RiscV ELF riscv*-*-elf
120 * Removed targets and native configurations
122 m88k running OpenBSD m88*-*-openbsd*
123 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
124 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
125 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
127 * Aarch64/Linux hardware watchpoints improvements
129 Hardware watchpoints on unaligned addresses are now properly
130 supported when running Linux kernel 4.10 or higher: read and access
131 watchpoints are no longer spuriously missed, and all watchpoints
132 lengths between 1 and 8 bytes are supported. On older kernels,
133 watchpoints set on unaligned addresses are no longer missed, with
134 the tradeoff that there is a possibility of false hits being
139 --enable-codesign=CERT
140 This can be used to invoke "codesign -s CERT" after building gdb.
141 This option is useful on macOS, where code signing is required for
142 gdb to work properly.
144 --disable-gdbcli has been removed
145 This is now silently accepted, but does nothing.
147 *** Changes in GDB 8.1
149 * GDB now supports dynamically creating arbitrary register groups specified
150 in XML target descriptions. This allows for finer grain grouping of
151 registers on systems with a large amount of registers.
153 * The 'ptype' command now accepts a '/o' flag, which prints the
154 offsets and sizes of fields in a struct, like the pahole(1) tool.
156 * New "--readnever" command line option instructs GDB to not read each
157 symbol file's symbolic debug information. This makes startup faster
158 but at the expense of not being able to perform symbolic debugging.
159 This option is intended for use cases where symbolic debugging will
160 not be used, e.g., when you only need to dump the debuggee's core.
162 * GDB now uses the GNU MPFR library, if available, to emulate target
163 floating-point arithmetic during expression evaluation when the target
164 uses different floating-point formats than the host. At least version
165 3.1 of GNU MPFR is required.
167 * GDB now supports access to the guarded-storage-control registers and the
168 software-based guarded-storage broadcast control registers on IBM z14.
170 * On Unix systems, GDB now supports transmitting environment variables
171 that are to be set or unset to GDBserver. These variables will
172 affect the environment to be passed to the remote inferior.
174 To inform GDB of environment variables that are to be transmitted to
175 GDBserver, use the "set environment" command. Only user set
176 environment variables are sent to GDBserver.
178 To inform GDB of environment variables that are to be unset before
179 the remote inferior is started by the GDBserver, use the "unset
180 environment" command.
182 * Completion improvements
184 ** GDB can now complete function parameters in linespecs and
185 explicit locations without quoting. When setting breakpoints,
186 quoting around functions names to help with TAB-completion is
187 generally no longer necessary. For example, this now completes
190 (gdb) b function(in[TAB]
191 (gdb) b function(int)
193 Related, GDB is no longer confused with completing functions in
194 C++ anonymous namespaces:
197 (gdb) b (anonymous namespace)::[TAB][TAB]
198 (anonymous namespace)::a_function()
199 (anonymous namespace)::b_function()
201 ** GDB now has much improved linespec and explicit locations TAB
202 completion support, that better understands what you're
203 completing and offers better suggestions. For example, GDB no
204 longer offers data symbols as possible completions when you're
205 setting a breakpoint.
207 ** GDB now TAB-completes label symbol names.
209 ** The "complete" command now mimics TAB completion accurately.
211 * New command line options (gcore)
214 Dump all memory mappings.
216 * Breakpoints on C++ functions are now set on all scopes by default
218 By default, breakpoints on functions/methods are now interpreted as
219 specifying all functions with the given name ignoring missing
220 leading scopes (namespaces and classes).
222 For example, assuming a C++ program with symbols named:
227 both commands "break func()" and "break B::func()" set a breakpoint
230 You can use the new flag "-qualified" to override this. This makes
231 GDB interpret the specified function name as a complete
232 fully-qualified name instead. For example, using the same C++
233 program, the "break -q B::func" command sets a breakpoint on
234 "B::func", only. A parameter has been added to the Python
235 gdb.Breakpoint constructor to achieve the same result when creating
236 a breakpoint from Python.
238 * Breakpoints on functions marked with C++ ABI tags
240 GDB can now set breakpoints on functions marked with C++ ABI tags
241 (e.g., [abi:cxx11]). See here for a description of ABI tags:
242 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
244 Functions with a C++11 abi tag are demangled/displayed like this:
246 function[abi:cxx11](int)
249 You can now set a breakpoint on such functions simply as if they had
252 (gdb) b function(int)
254 Or if you need to disambiguate between tags, like:
256 (gdb) b function[abi:other_tag](int)
258 Tab completion was adjusted accordingly as well.
262 ** New events gdb.new_inferior, gdb.inferior_deleted, and
263 gdb.new_thread are emitted. See the manual for further
264 description of these.
266 ** A new function, "gdb.rbreak" has been added to the Python API.
267 This function allows the setting of a large number of breakpoints
268 via a regex pattern in Python. See the manual for further details.
270 ** Python breakpoints can now accept explicit locations. See the
271 manual for a further description of this feature.
274 * New features in the GDB remote stub, GDBserver
276 ** GDBserver is now able to start inferior processes with a
277 specified initial working directory.
279 The user can set the desired working directory to be used from
280 GDB using the new "set cwd" command.
282 ** New "--selftest" command line option runs some GDBserver self
283 tests. These self tests are disabled in releases.
285 ** On Unix systems, GDBserver now does globbing expansion and variable
286 substitution in inferior command line arguments.
288 This is done by starting inferiors using a shell, like GDB does.
289 See "set startup-with-shell" in the user manual for how to disable
290 this from GDB when using "target extended-remote". When using
291 "target remote", you can disable the startup with shell by using the
292 new "--no-startup-with-shell" GDBserver command line option.
294 ** On Unix systems, GDBserver now supports receiving environment
295 variables that are to be set or unset from GDB. These variables
296 will affect the environment to be passed to the inferior.
298 * When catching an Ada exception raised with a message, GDB now prints
299 the message in the catchpoint hit notification. In GDB/MI mode, that
300 information is provided as an extra field named "exception-message"
301 in the *stopped notification.
303 * Trait objects can now be inspected When debugging Rust code. This
304 requires compiler support which will appear in Rust 1.24.
308 QEnvironmentHexEncoded
309 Inform GDBserver of an environment variable that is to be passed to
310 the inferior when starting it.
313 Inform GDBserver of an environment variable that is to be unset
314 before starting the remote inferior.
317 Inform GDBserver that the environment should be reset (i.e.,
318 user-set environment variables should be unset).
321 Indicates whether the inferior must be started with a shell or not.
324 Tell GDBserver that the inferior to be started should use a specific
327 * The "maintenance print c-tdesc" command now takes an optional
328 argument which is the file name of XML target description.
330 * The "maintenance selftest" command now takes an optional argument to
331 filter the tests to be run.
333 * The "enable", and "disable" commands now accept a range of
334 breakpoint locations, e.g. "enable 1.3-5".
339 Set and show the current working directory for the inferior.
342 Set and show compilation command used for compiling and injecting code
343 with the 'compile' commands.
345 set debug separate-debug-file
346 show debug separate-debug-file
347 Control the display of debug output about separate debug file search.
349 set dump-excluded-mappings
350 show dump-excluded-mappings
351 Control whether mappings marked with the VM_DONTDUMP flag should be
352 dumped when generating a core file.
355 List the registered selftests.
358 Start the debugged program stopping at the first instruction.
361 Control display of debugging messages related to OpenRISC targets.
363 set|show print type nested-type-limit
364 Set and show the limit of nesting level for nested types that the
365 type printer will show.
367 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
370 * Safer/improved support for debugging with no debug info
372 GDB no longer assumes functions with no debug information return
375 This means that GDB now refuses to call such functions unless you
376 tell it the function's type, by either casting the call to the
377 declared return type, or by casting the function to a function
378 pointer of the right type, and calling that:
380 (gdb) p getenv ("PATH")
381 'getenv' has unknown return type; cast the call to its declared return type
382 (gdb) p (char *) getenv ("PATH")
383 $1 = 0x7fffffffe "/usr/local/bin:/"...
384 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
385 $2 = 0x7fffffffe "/usr/local/bin:/"...
387 Similarly, GDB no longer assumes that global variables with no debug
388 info have type 'int', and refuses to print the variable's value
389 unless you tell it the variable's type:
392 'var' has unknown type; cast it to its declared type
396 * New native configurations
398 FreeBSD/aarch64 aarch64*-*-freebsd*
399 FreeBSD/arm arm*-*-freebsd*
403 FreeBSD/aarch64 aarch64*-*-freebsd*
404 FreeBSD/arm arm*-*-freebsd*
405 OpenRISC ELF or1k*-*-elf
407 * Removed targets and native configurations
409 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
411 *** Changes in GDB 8.0
413 * GDB now supports access to the PKU register on GNU/Linux. The register is
414 added by the Memory Protection Keys for Userspace feature which will be
415 available in future Intel CPUs.
417 * GDB now supports C++11 rvalue references.
421 ** New functions to start, stop and access a running btrace recording.
422 ** Rvalue references are now supported in gdb.Type.
424 * GDB now supports recording and replaying rdrand and rdseed Intel 64
427 * Building GDB and GDBserver now requires a C++11 compiler.
429 For example, GCC 4.8 or later.
431 It is no longer possible to build GDB or GDBserver with a C
432 compiler. The --disable-build-with-cxx configure option has been
435 * Building GDB and GDBserver now requires GNU make >= 3.81.
437 It is no longer supported to build GDB or GDBserver with another
438 implementation of the make program or an earlier version of GNU make.
440 * Native debugging on MS-Windows supports command-line redirection
442 Command-line arguments used for starting programs on MS-Windows can
443 now include redirection symbols supported by native Windows shells,
444 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
445 as "run", "start", and "set args", as well as the corresponding MI
448 * Support for thread names on MS-Windows.
450 GDB now catches and handles the special exception that programs
451 running on MS-Windows use to assign names to threads in the
454 * Support for Java programs compiled with gcj has been removed.
456 * User commands now accept an unlimited number of arguments.
457 Previously, only up to 10 was accepted.
459 * The "eval" command now expands user-defined command arguments.
461 This makes it easier to process a variable number of arguments:
466 eval "print $arg%d", $i
471 * Target descriptions can now describe registers for sparc32 and sparc64.
473 * GDB now supports DWARF version 5 (debug information format).
474 Its .debug_names index is not yet supported.
476 * New native configurations
478 FreeBSD/mips mips*-*-freebsd
482 Synopsys ARC arc*-*-elf32
483 FreeBSD/mips mips*-*-freebsd
485 * Removed targets and native configurations
487 Alpha running FreeBSD alpha*-*-freebsd*
488 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
493 Erases all the flash memory regions reported by the target.
495 maint print arc arc-instruction address
496 Print internal disassembler information about instruction at a given address.
500 set disassembler-options
501 show disassembler-options
502 Controls the passing of target specific information to the disassembler.
503 If it is necessary to specify more than one disassembler option then
504 multiple options can be placed together into a comma separated list.
505 The default value is the empty string. Currently, the only supported
506 targets are ARM, PowerPC and S/390.
511 Erases all the flash memory regions reported by the target. This is
512 equivalent to the CLI command flash-erase.
514 -file-list-shared-libraries
515 List the shared libraries in the program. This is
516 equivalent to the CLI command "info shared".
519 Catchpoints stopping the program when Ada exceptions are
520 handled. This is equivalent to the CLI command "catch handlers".
522 *** Changes in GDB 7.12
524 * GDB and GDBserver now build with a C++ compiler by default.
526 The --enable-build-with-cxx configure option is now enabled by
527 default. One must now explicitly configure with
528 --disable-build-with-cxx in order to build with a C compiler. This
529 option will be removed in a future release.
531 * GDBserver now supports recording btrace without maintaining an active
534 * GDB now supports a negative repeat count in the 'x' command to examine
535 memory backward from the given address. For example:
538 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
539 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
540 (gdb) x/-5i 0x0000000000400580
541 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
542 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
543 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
544 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
545 0x40057b <main(int, char**)+25>:
546 callq 0x400536 <Func1(int, char const*)>
548 * Fortran: Support structures with fields of dynamic types and
549 arrays of dynamic types.
551 * The symbol dumping maintenance commands have new syntax.
552 maint print symbols [-pc address] [--] [filename]
553 maint print symbols [-objfile objfile] [-source source] [--] [filename]
554 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
555 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
556 maint print msymbols [-objfile objfile] [--] [filename]
558 * GDB now supports multibit bitfields and enums in target register
561 * New Python-based convenience function $_as_string(val), which returns
562 the textual representation of a value. This function is especially
563 useful to obtain the text label of an enum value.
565 * Intel MPX bound violation handling.
567 Segmentation faults caused by a Intel MPX boundary violation
568 now display the kind of violation (upper or lower), the memory
569 address accessed and the memory bounds, along with the usual
570 signal received and code location.
574 Program received signal SIGSEGV, Segmentation fault
575 Upper bound violation while accessing address 0x7fffffffc3b3
576 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
577 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
579 * Rust language support.
580 GDB now supports debugging programs written in the Rust programming
581 language. See https://www.rust-lang.org/ for more information about
584 * Support for running interpreters on specified input/output devices
586 GDB now supports a new mechanism that allows frontends to provide
587 fully featured GDB console views, as a better alternative to
588 building such views on top of the "-interpreter-exec console"
589 command. See the new "new-ui" command below. With that command,
590 frontends can now start GDB in the traditional command-line mode
591 running in an embedded terminal emulator widget, and create a
592 separate MI interpreter running on a specified i/o device. In this
593 way, GDB handles line editing, history, tab completion, etc. in the
594 console all by itself, and the GUI uses the separate MI interpreter
595 for its own control and synchronization, invisible to the command
598 * The "catch syscall" command catches groups of related syscalls.
600 The "catch syscall" command now supports catching a group of related
601 syscalls using the 'group:' or 'g:' prefix.
606 skip -gfile file-glob-pattern
607 skip -function function
608 skip -rfunction regular-expression
609 A generalized form of the skip command, with new support for
610 glob-style file names and regular expressions for function names.
611 Additionally, a file spec and a function spec may now be combined.
613 maint info line-table REGEXP
614 Display the contents of GDB's internal line table data struture.
617 Run any GDB unit tests that were compiled in.
620 Start a new user interface instance running INTERP as interpreter,
621 using the TTY file for input/output.
625 ** gdb.Breakpoint objects have a new attribute "pending", which
626 indicates whether the breakpoint is pending.
627 ** Three new breakpoint-related events have been added:
628 gdb.breakpoint_created, gdb.breakpoint_modified, and
629 gdb.breakpoint_deleted.
632 Signal ("set") the given MS-Windows event object. This is used in
633 conjunction with the Windows JIT debugging (AeDebug) support, where
634 the OS suspends a crashing process until a debugger can attach to
635 it. Resuming the crashing process, in order to debug it, is done by
638 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
639 was added in GDBserver, including JIT compiling fast tracepoint's
640 conditional expression bytecode into native code.
642 * Support for various remote target protocols and ROM monitors has
645 target m32rsdi Remote M32R debugging over SDI
646 target mips MIPS remote debugging protocol
647 target pmon PMON ROM monitor
648 target ddb NEC's DDB variant of PMON for Vr4300
649 target rockhopper NEC RockHopper variant of PMON
650 target lsi LSI variant of PMO
652 * Support for tracepoints and fast tracepoints on powerpc-linux,
653 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
654 including JIT compiling fast tracepoint's conditional expression
655 bytecode into native code.
657 * MI async record =record-started now includes the method and format used for
658 recording. For example:
660 =record-started,thread-group="i1",method="btrace",format="bts"
662 * MI async record =thread-selected now includes the frame field. For example:
664 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
668 Andes NDS32 nds32*-*-elf
670 *** Changes in GDB 7.11
672 * GDB now supports debugging kernel-based threads on FreeBSD.
674 * Per-inferior thread numbers
676 Thread numbers are now per inferior instead of global. If you're
677 debugging multiple inferiors, GDB displays thread IDs using a
678 qualified INF_NUM.THR_NUM form. For example:
682 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
683 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
684 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
685 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
687 As consequence, thread numbers as visible in the $_thread
688 convenience variable and in Python's InferiorThread.num attribute
689 are no longer unique between inferiors.
691 GDB now maintains a second thread ID per thread, referred to as the
692 global thread ID, which is the new equivalent of thread numbers in
693 previous releases. See also $_gthread below.
695 For backwards compatibility, MI's thread IDs always refer to global
698 * Commands that accept thread IDs now accept the qualified
699 INF_NUM.THR_NUM form as well. For example:
702 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
705 * In commands that accept a list of thread IDs, you can now refer to
706 all threads of an inferior using a star wildcard. GDB accepts
707 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
708 refer to all threads of the current inferior. For example, "info
711 * You can use "info threads -gid" to display the global thread ID of
714 * The new convenience variable $_gthread holds the global number of
717 * The new convenience variable $_inferior holds the number of the
720 * GDB now displays the ID and name of the thread that hit a breakpoint
721 or received a signal, if your program is multi-threaded. For
724 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
725 Thread 1 "main" received signal SIGINT, Interrupt.
727 * Record btrace now supports non-stop mode.
729 * Support for tracepoints on aarch64-linux was added in GDBserver.
731 * The 'record instruction-history' command now indicates speculative execution
732 when using the Intel Processor Trace recording format.
734 * GDB now allows users to specify explicit locations, bypassing
735 the linespec parser. This feature is also available to GDB/MI
738 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
739 GDB now is able to debug both AArch64 applications and ARM applications
742 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
743 including JIT compiling fast tracepoint's conditional expression bytecode
746 * GDB now supports displaced stepping on AArch64 GNU/Linux.
748 * "info threads", "info inferiors", "info display", "info checkpoints"
749 and "maint info program-spaces" now list the corresponding items in
750 ascending ID order, for consistency with all other "info" commands.
752 * In Ada, the overloads selection menu has been enhanced to display the
753 parameter types and the return types for the matching overloaded subprograms.
757 maint set target-non-stop (on|off|auto)
758 maint show target-non-stop
759 Control whether GDB targets always operate in non-stop mode even if
760 "set non-stop" is "off". The default is "auto", meaning non-stop
761 mode is enabled if supported by the target.
763 maint set bfd-sharing
764 maint show bfd-sharing
765 Control the reuse of bfd objects.
769 Control display of debugging info regarding bfd caching.
773 Control display of debugging info regarding FreeBSD threads.
775 set remote multiprocess-extensions-packet
776 show remote multiprocess-extensions-packet
777 Set/show the use of the remote protocol multiprocess extensions.
779 set remote thread-events
780 show remote thread-events
781 Set/show the use of thread create/exit events.
783 set ada print-signatures on|off
784 show ada print-signatures"
785 Control whether parameter types and return types are displayed in overloads
786 selection menus. It is activaled (@code{on}) by default.
790 Controls the maximum size of memory, in bytes, that GDB will
791 allocate for value contents. Prevents incorrect programs from
792 causing GDB to allocate overly large buffers. Default is 64k.
794 * The "disassemble" command accepts a new modifier: /s.
795 It prints mixed source+disassembly like /m with two differences:
796 - disassembled instructions are now printed in program order, and
797 - and source for all relevant files is now printed.
798 The "/m" option is now considered deprecated: its "source-centric"
799 output hasn't proved useful in practice.
801 * The "record instruction-history" command accepts a new modifier: /s.
802 It behaves exactly like /m and prints mixed source+disassembly.
804 * The "set scheduler-locking" command supports a new mode "replay".
805 It behaves like "off" in record mode and like "on" in replay mode.
807 * Support for various ROM monitors has been removed:
809 target dbug dBUG ROM monitor for Motorola ColdFire
810 target picobug Motorola picobug monitor
811 target dink32 DINK32 ROM monitor for PowerPC
812 target m32r Renesas M32R/D ROM monitor
813 target mon2000 mon2000 ROM monitor
814 target ppcbug PPCBUG ROM monitor for PowerPC
816 * Support for reading/writing memory and extracting values on architectures
817 whose memory is addressable in units of any integral multiple of 8 bits.
820 Allows to break when an Ada exception is handled.
825 Indicates that an exec system call was executed.
827 exec-events feature in qSupported
828 The qSupported packet allows GDB to request support for exec
829 events using the new 'gdbfeature' exec-event, and the qSupported
830 response can contain the corresponding 'stubfeature'. Set and
831 show commands can be used to display whether these features are enabled.
834 Equivalent to interrupting with the ^C character, but works in
837 thread created stop reason (T05 create:...)
838 Indicates that the thread was just created and is stopped at entry.
840 thread exit stop reply (w exitcode;tid)
841 Indicates that the thread has terminated.
844 Enables/disables thread create and exit event reporting. For
845 example, this is used in non-stop mode when GDB stops a set of
846 threads and synchronously waits for the their corresponding stop
847 replies. Without exit events, if one of the threads exits, GDB
848 would hang forever not knowing that it should no longer expect a
849 stop for that same thread.
852 Indicates that there are no resumed threads left in the target (all
853 threads are stopped). The remote stub reports support for this stop
854 reply to GDB's qSupported query.
857 Enables/disables catching syscalls from the inferior process.
858 The remote stub reports support for this packet to GDB's qSupported query.
860 syscall_entry stop reason
861 Indicates that a syscall was just called.
863 syscall_return stop reason
864 Indicates that a syscall just returned.
866 * Extended-remote exec events
868 ** GDB now has support for exec events on extended-remote Linux targets.
869 For such targets with Linux kernels 2.5.46 and later, this enables
870 follow-exec-mode and exec catchpoints.
872 set remote exec-event-feature-packet
873 show remote exec-event-feature-packet
874 Set/show the use of the remote exec event feature.
876 * Thread names in remote protocol
878 The reply to qXfer:threads:read may now include a name attribute for each
881 * Target remote mode fork and exec events
883 ** GDB now has support for fork and exec events on target remote mode
884 Linux targets. For such targets with Linux kernels 2.5.46 and later,
885 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
886 fork and exec catchpoints.
888 * Remote syscall events
890 ** GDB now has support for catch syscall on remote Linux targets,
891 currently enabled on x86/x86_64 architectures.
893 set remote catch-syscall-packet
894 show remote catch-syscall-packet
895 Set/show the use of the remote catch syscall feature.
899 ** The -var-set-format command now accepts the zero-hexadecimal
900 format. It outputs data in hexadecimal format with zero-padding on the
905 ** gdb.InferiorThread objects have a new attribute "global_num",
906 which refers to the thread's global thread ID. The existing
907 "num" attribute now refers to the thread's per-inferior number.
908 See "Per-inferior thread numbers" above.
909 ** gdb.InferiorThread objects have a new attribute "inferior", which
910 is the Inferior object the thread belongs to.
912 *** Changes in GDB 7.10
914 * Support for process record-replay and reverse debugging on aarch64*-linux*
915 targets has been added. GDB now supports recording of A64 instruction set
916 including advance SIMD instructions.
918 * Support for Sun's version of the "stabs" debug file format has been removed.
920 * GDB now honors the content of the file /proc/PID/coredump_filter
921 (PID is the process ID) on GNU/Linux systems. This file can be used
922 to specify the types of memory mappings that will be included in a
923 corefile. For more information, please refer to the manual page of
924 "core(5)". GDB also has a new command: "set use-coredump-filter
925 on|off". It allows to set whether GDB will read the content of the
926 /proc/PID/coredump_filter file when generating a corefile.
928 * The "info os" command on GNU/Linux can now display information on
930 "info os cpus" Listing of all cpus/cores on the system
932 * GDB has two new commands: "set serial parity odd|even|none" and
933 "show serial parity". These allows to set or show parity for the
936 * The "info source" command now displays the producer string if it was
937 present in the debug info. This typically includes the compiler version
938 and may include things like its command line arguments.
940 * The "info dll", an alias of the "info sharedlibrary" command,
941 is now available on all platforms.
943 * Directory names supplied to the "set sysroot" commands may be
944 prefixed with "target:" to tell GDB to access shared libraries from
945 the target system, be it local or remote. This replaces the prefix
946 "remote:". The default sysroot has been changed from "" to
947 "target:". "remote:" is automatically converted to "target:" for
948 backward compatibility.
950 * The system root specified by "set sysroot" will be prepended to the
951 filename of the main executable (if reported to GDB as absolute by
952 the operating system) when starting processes remotely, and when
953 attaching to already-running local or remote processes.
955 * GDB now supports automatic location and retrieval of executable
956 files from remote targets. Remote debugging can now be initiated
957 using only a "target remote" or "target extended-remote" command
958 (no "set sysroot" or "file" commands are required). See "New remote
961 * The "dump" command now supports verilog hex format.
963 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
965 * On GNU/Linux, GDB and gdbserver are now able to access executable
966 and shared library files without a "set sysroot" command when
967 attaching to processes running in different mount namespaces from
968 the debugger. This makes it possible to attach to processes in
969 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
970 See "New remote packets" below.
972 * The "tui reg" command now provides completion for all of the
973 available register groups, including target specific groups.
975 * The HISTSIZE environment variable is no longer read when determining
976 the size of GDB's command history. GDB now instead reads the dedicated
977 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
978 disables truncation of command history. Non-numeric values of GDBHISTSIZE
983 ** Memory ports can now be unbuffered.
987 ** gdb.Objfile objects have a new attribute "username",
988 which is the name of the objfile as specified by the user,
989 without, for example, resolving symlinks.
990 ** You can now write frame unwinders in Python.
991 ** gdb.Type objects have a new method "optimized_out",
992 returning optimized out gdb.Value instance of this type.
993 ** gdb.Value objects have new methods "reference_value" and
994 "const_value" which return a reference to the value and a
995 "const" version of the value respectively.
999 maint print symbol-cache
1000 Print the contents of the symbol cache.
1002 maint print symbol-cache-statistics
1003 Print statistics of symbol cache usage.
1005 maint flush-symbol-cache
1006 Flush the contents of the symbol cache.
1010 Start branch trace recording using Branch Trace Store (BTS) format.
1013 Evaluate expression by using the compiler and print result.
1017 Explicit commands for enabling and disabling tui mode.
1020 set mpx bound on i386 and amd64
1021 Support for bound table investigation on Intel MPX enabled applications.
1025 Start branch trace recording using Intel Processor Trace format.
1028 Print information about branch tracing internals.
1030 maint btrace packet-history
1031 Print the raw branch tracing data.
1033 maint btrace clear-packet-history
1034 Discard the stored raw branch tracing data.
1037 Discard all branch tracing data. It will be fetched and processed
1038 anew by the next "record" command.
1043 Renamed from "set debug dwarf2-die".
1044 show debug dwarf-die
1045 Renamed from "show debug dwarf2-die".
1047 set debug dwarf-read
1048 Renamed from "set debug dwarf2-read".
1049 show debug dwarf-read
1050 Renamed from "show debug dwarf2-read".
1052 maint set dwarf always-disassemble
1053 Renamed from "maint set dwarf2 always-disassemble".
1054 maint show dwarf always-disassemble
1055 Renamed from "maint show dwarf2 always-disassemble".
1057 maint set dwarf max-cache-age
1058 Renamed from "maint set dwarf2 max-cache-age".
1059 maint show dwarf max-cache-age
1060 Renamed from "maint show dwarf2 max-cache-age".
1062 set debug dwarf-line
1063 show debug dwarf-line
1064 Control display of debugging info regarding DWARF line processing.
1067 show max-completions
1068 Set the maximum number of candidates to be considered during
1069 completion. The default value is 200. This limit allows GDB
1070 to avoid generating large completion lists, the computation of
1071 which can cause the debugger to become temporarily unresponsive.
1073 set history remove-duplicates
1074 show history remove-duplicates
1075 Control the removal of duplicate history entries.
1077 maint set symbol-cache-size
1078 maint show symbol-cache-size
1079 Control the size of the symbol cache.
1081 set|show record btrace bts buffer-size
1082 Set and show the size of the ring buffer used for branch tracing in
1084 The obtained size may differ from the requested size. Use "info
1085 record" to see the obtained buffer size.
1087 set debug linux-namespaces
1088 show debug linux-namespaces
1089 Control display of debugging info regarding Linux namespaces.
1091 set|show record btrace pt buffer-size
1092 Set and show the size of the ring buffer used for branch tracing in
1093 Intel Processor Trace format.
1094 The obtained size may differ from the requested size. Use "info
1095 record" to see the obtained buffer size.
1097 maint set|show btrace pt skip-pad
1098 Set and show whether PAD packets are skipped when computing the
1101 * The command 'thread apply all' can now support new option '-ascending'
1102 to call its specified command for all threads in ascending order.
1104 * Python/Guile scripting
1106 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1107 special section named `.debug_gdb_scripts'.
1109 * New remote packets
1111 qXfer:btrace-conf:read
1112 Return the branch trace configuration for the current thread.
1114 Qbtrace-conf:bts:size
1115 Set the requested ring buffer size for branch tracing in BTS format.
1118 Enable Intel Procesor Trace-based branch tracing for the current
1119 process. The remote stub reports support for this packet to GDB's
1122 Qbtrace-conf:pt:size
1123 Set the requested ring buffer size for branch tracing in Intel Processor
1127 Indicates a memory breakpoint instruction was executed, irrespective
1128 of whether it was GDB that planted the breakpoint or the breakpoint
1129 is hardcoded in the program. This is required for correct non-stop
1133 Indicates the target stopped for a hardware breakpoint. This is
1134 required for correct non-stop mode operation.
1137 Return information about files on the remote system.
1139 qXfer:exec-file:read
1140 Return the full absolute name of the file that was executed to
1141 create a process running on the remote system.
1144 Select the filesystem on which vFile: operations with filename
1145 arguments will operate. This is required for GDB to be able to
1146 access files on remote targets where the remote stub does not
1147 share a common filesystem with the inferior(s).
1150 Indicates that a fork system call was executed.
1153 Indicates that a vfork system call was executed.
1155 vforkdone stop reason
1156 Indicates that a vfork child of the specified process has executed
1157 an exec or exit, allowing the vfork parent to resume execution.
1159 fork-events and vfork-events features in qSupported
1160 The qSupported packet allows GDB to request support for fork and
1161 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1162 and the qSupported response can contain the corresponding
1163 'stubfeatures'. Set and show commands can be used to display
1164 whether these features are enabled.
1166 * Extended-remote fork events
1168 ** GDB now has support for fork events on extended-remote Linux
1169 targets. For targets with Linux kernels 2.5.60 and later, this
1170 enables follow-fork-mode and detach-on-fork for both fork and
1171 vfork, as well as fork and vfork catchpoints.
1173 * The info record command now shows the recording format and the
1174 branch tracing configuration for the current thread when using
1175 the btrace record target.
1176 For the BTS format, it shows the ring buffer size.
1178 * GDB now has support for DTrace USDT (Userland Static Defined
1179 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1181 * GDB now supports access to vector registers on S/390 GNU/Linux
1184 * Removed command line options
1186 -xdb HP-UX XDB compatibility mode.
1188 * Removed targets and native configurations
1190 HP/PA running HP-UX hppa*-*-hpux*
1191 Itanium running HP-UX ia64-*-hpux*
1193 * New configure options
1196 This configure option allows the user to build GDB with support for
1197 Intel Processor Trace (default: auto). This requires libipt.
1199 --with-libipt-prefix=PATH
1200 Specify the path to the version of libipt that GDB should use.
1201 $PATH/include should contain the intel-pt.h header and
1202 $PATH/lib should contain the libipt.so library.
1204 *** Changes in GDB 7.9.1
1208 ** Xmethods can now specify a result type.
1210 *** Changes in GDB 7.9
1212 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1216 ** You can now access frame registers from Python scripts.
1217 ** New attribute 'producer' for gdb.Symtab objects.
1218 ** gdb.Objfile objects have a new attribute "progspace",
1219 which is the gdb.Progspace object of the containing program space.
1220 ** gdb.Objfile objects have a new attribute "owner".
1221 ** gdb.Objfile objects have a new attribute "build_id",
1222 which is the build ID generated when the file was built.
1223 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1224 ** A new event "gdb.clear_objfiles" has been added, triggered when
1225 selecting a new file to debug.
1226 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1227 ** New function gdb.lookup_objfile.
1229 New events which are triggered when GDB modifies the state of the
1232 ** gdb.events.inferior_call_pre: Function call is about to be made.
1233 ** gdb.events.inferior_call_post: Function call has just been made.
1234 ** gdb.events.memory_changed: A memory location has been altered.
1235 ** gdb.events.register_changed: A register has been altered.
1237 * New Python-based convenience functions:
1239 ** $_caller_is(name [, number_of_frames])
1240 ** $_caller_matches(regexp [, number_of_frames])
1241 ** $_any_caller_is(name [, number_of_frames])
1242 ** $_any_caller_matches(regexp [, number_of_frames])
1244 * GDB now supports the compilation and injection of source code into
1245 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1246 to compile the source code to object code, and if successful, inject
1247 and execute that code within the current context of the inferior.
1248 Currently the C language is supported. The commands used to
1249 interface with this new feature are:
1251 compile code [-raw|-r] [--] [source code]
1252 compile file [-raw|-r] filename
1256 demangle [-l language] [--] name
1257 Demangle "name" in the specified language, or the current language
1258 if elided. This command is renamed from the "maint demangle" command.
1259 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1260 as "maint demangler-warning".
1262 queue-signal signal-name-or-number
1263 Queue a signal to be delivered to the thread when it is resumed.
1265 add-auto-load-scripts-directory directory
1266 Add entries to the list of directories from which to load auto-loaded
1269 maint print user-registers
1270 List all currently available "user" registers.
1272 compile code [-r|-raw] [--] [source code]
1273 Compile, inject, and execute in the inferior the executable object
1274 code produced by compiling the provided source code.
1276 compile file [-r|-raw] filename
1277 Compile and inject into the inferior the executable object code
1278 produced by compiling the source code stored in the filename
1281 * On resume, GDB now always passes the signal the program had stopped
1282 for to the thread the signal was sent to, even if the user changed
1283 threads before resuming. Previously GDB would often (but not
1284 always) deliver the signal to the thread that happens to be current
1287 * Conversely, the "signal" command now consistently delivers the
1288 requested signal to the current thread. GDB now asks for
1289 confirmation if the program had stopped for a signal and the user
1290 switched threads meanwhile.
1292 * "breakpoint always-inserted" modes "off" and "auto" merged.
1294 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1295 won't remove breakpoints from the target until all threads stop,
1296 even in non-stop mode. The "auto" mode has been removed, and "off"
1297 is now the default mode.
1301 set debug symbol-lookup
1302 show debug symbol-lookup
1303 Control display of debugging info regarding symbol lookup.
1307 ** The -list-thread-groups command outputs an exit-code field for
1308 inferiors that have exited.
1312 MIPS SDE mips*-sde*-elf*
1316 Support for these obsolete configurations has been removed.
1318 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1319 SGI Irix-5.x mips-*-irix5*
1320 SGI Irix-6.x mips-*-irix6*
1321 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1322 VAX running Ultrix vax-*-ultrix*
1324 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1325 and "assf"), have been removed. Use the "sharedlibrary" command, or
1326 its alias "share", instead.
1328 *** Changes in GDB 7.8
1330 * New command line options
1333 This is an alias for the --data-directory option.
1335 * GDB supports printing and modifying of variable length automatic arrays
1336 as specified in ISO C99.
1338 * The ARM simulator now supports instruction level tracing
1339 with or without disassembly.
1343 GDB now has support for scripting using Guile. Whether this is
1344 available is determined at configure time.
1345 Guile version 2.0 or greater is required.
1346 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1348 * New commands (for set/show, see "New options" below)
1352 Invoke CODE by passing it to the Guile interpreter.
1356 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1358 info auto-load guile-scripts [regexp]
1359 Print the list of automatically loaded Guile scripts.
1361 * The source command is now capable of sourcing Guile scripts.
1362 This feature is dependent on the debugger being built with Guile support.
1366 set print symbol-loading (off|brief|full)
1367 show print symbol-loading
1368 Control whether to print informational messages when loading symbol
1369 information for a file. The default is "full", but when debugging
1370 programs with large numbers of shared libraries the amount of output
1371 becomes less useful.
1373 set guile print-stack (none|message|full)
1374 show guile print-stack
1375 Show a stack trace when an error is encountered in a Guile script.
1377 set auto-load guile-scripts (on|off)
1378 show auto-load guile-scripts
1379 Control auto-loading of Guile script files.
1381 maint ada set ignore-descriptive-types (on|off)
1382 maint ada show ignore-descriptive-types
1383 Control whether the debugger should ignore descriptive types in Ada
1384 programs. The default is not to ignore the descriptive types. See
1385 the user manual for more details on descriptive types and the intended
1386 usage of this option.
1388 set auto-connect-native-target
1390 Control whether GDB is allowed to automatically connect to the
1391 native target for the run, attach, etc. commands when not connected
1392 to any target yet. See also "target native" below.
1394 set record btrace replay-memory-access (read-only|read-write)
1395 show record btrace replay-memory-access
1396 Control what memory accesses are allowed during replay.
1398 maint set target-async (on|off)
1399 maint show target-async
1400 This controls whether GDB targets operate in synchronous or
1401 asynchronous mode. Normally the default is asynchronous, if it is
1402 available; but this can be changed to more easily debug problems
1403 occurring only in synchronous mode.
1405 set mi-async (on|off)
1407 Control whether MI asynchronous mode is preferred. This supersedes
1408 "set target-async" of previous GDB versions.
1410 * "set target-async" is deprecated as a CLI option and is now an alias
1411 for "set mi-async" (only puts MI into async mode).
1413 * Background execution commands (e.g., "c&", "s&", etc.) are now
1414 possible ``out of the box'' if the target supports them. Previously
1415 the user would need to explicitly enable the possibility with the
1416 "set target-async on" command.
1418 * New features in the GDB remote stub, GDBserver
1420 ** New option --debug-format=option1[,option2,...] allows one to add
1421 additional text to each output. At present only timestamps
1422 are supported: --debug-format=timestamps.
1423 Timestamps can also be turned on with the
1424 "monitor set debug-format timestamps" command from GDB.
1426 * The 'record instruction-history' command now starts counting instructions
1427 at one. This also affects the instruction ranges reported by the
1428 'record function-call-history' command when given the /i modifier.
1430 * The command 'record function-call-history' supports a new modifier '/c' to
1431 indent the function names based on their call stack depth.
1432 The fields for the '/i' and '/l' modifier have been reordered.
1433 The source line range is now prefixed with 'at'.
1434 The instruction range is now prefixed with 'inst'.
1435 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1436 "record instruction-history" and "list" commands.
1438 * The ranges given as arguments to the 'record function-call-history' and
1439 'record instruction-history' commands are now inclusive.
1441 * The btrace record target now supports the 'record goto' command.
1442 For locations inside the execution trace, the back trace is computed
1443 based on the information stored in the execution trace.
1445 * The btrace record target supports limited reverse execution and replay.
1446 The target does not record data and therefore does not allow reading
1447 memory or registers.
1449 * The "catch syscall" command now works on s390*-linux* targets.
1451 * The "compare-sections" command is no longer specific to target
1452 remote. It now works with all targets.
1454 * All native targets are now consistently called "native".
1455 Consequently, the "target child", "target GNU", "target djgpp",
1456 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1457 commands have been replaced with "target native". The QNX/NTO port
1458 leaves the "procfs" target in place and adds a "native" target for
1459 consistency with other ports. The impact on users should be minimal
1460 as these commands previously either throwed an error, or were
1461 no-ops. The target's name is visible in the output of the following
1462 commands: "help target", "info target", "info files", "maint print
1465 * The "target native" command now connects to the native target. This
1466 can be used to launch native programs even when "set
1467 auto-connect-native-target" is set to off.
1469 * GDB now supports access to Intel MPX registers on GNU/Linux.
1471 * Support for Intel AVX-512 registers on GNU/Linux.
1472 Support displaying and modifying Intel AVX-512 registers
1473 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1475 * New remote packets
1477 qXfer:btrace:read's annex
1478 The qXfer:btrace:read packet supports a new annex 'delta' to read
1479 branch trace incrementally.
1483 ** Valid Python operations on gdb.Value objects representing
1484 structs/classes invoke the corresponding overloaded operators if
1486 ** New `Xmethods' feature in the Python API. Xmethods are
1487 additional methods or replacements for existing methods of a C++
1488 class. This feature is useful for those cases where a method
1489 defined in C++ source code could be inlined or optimized out by
1490 the compiler, making it unavailable to GDB.
1493 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1495 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1496 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1497 its alias "share", instead.
1499 * The commands "set remotebaud" and "show remotebaud" are no longer
1500 supported. Use "set serial baud" and "show serial baud" (respectively)
1505 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1506 target-async". The latter is left as a deprecated alias of the
1507 former for backward compatibility. If the target supports it,
1508 CLI background execution commands are now always possible by
1509 default, independently of whether the frontend stated a
1510 preference for asynchronous execution with "-gdb-set mi-async".
1511 Previously "-gdb-set target-async off" affected both MI execution
1512 commands and CLI execution commands.
1514 *** Changes in GDB 7.7
1516 * Improved support for process record-replay and reverse debugging on
1517 arm*-linux* targets. Support for thumb32 and syscall instruction
1518 recording has been added.
1520 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1522 * GDB now supports Fission DWP file format version 2.
1523 http://gcc.gnu.org/wiki/DebugFission
1525 * New convenience function "$_isvoid", to check whether an expression
1526 is void. A void expression is an expression where the type of the
1527 result is "void". For example, some convenience variables may be
1528 "void" when evaluated (e.g., "$_exitcode" before the execution of
1529 the program being debugged; or an undefined convenience variable).
1530 Another example, when calling a function whose return type is
1533 * The "maintenance print objfiles" command now takes an optional regexp.
1535 * The "catch syscall" command now works on arm*-linux* targets.
1537 * GDB now consistently shows "<not saved>" when printing values of
1538 registers the debug info indicates have not been saved in the frame
1539 and there's nowhere to retrieve them from
1540 (callee-saved/call-clobbered registers):
1545 (gdb) info registers rax
1548 Before, the former would print "<optimized out>", and the latter
1549 "*value not available*".
1551 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1556 ** Frame filters and frame decorators have been added.
1557 ** Temporary breakpoints are now supported.
1558 ** Line tables representation has been added.
1559 ** New attribute 'parent_type' for gdb.Field objects.
1560 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1561 ** New attribute 'name' for gdb.Type objects.
1565 Nios II ELF nios2*-*-elf
1566 Nios II GNU/Linux nios2*-*-linux
1567 Texas Instruments MSP430 msp430*-*-elf
1569 * Removed native configurations
1571 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1572 been removed. ELF variants of these configurations are kept supported.
1574 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1575 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1576 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1577 i[34567]86-*-openbsd3.[0-3]
1578 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1579 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1580 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1584 Like "catch throw", but catches a re-thrown exception.
1585 maint check-psymtabs
1586 Renamed from old "maint check-symtabs".
1588 Perform consistency checks on symtabs.
1589 maint expand-symtabs
1590 Expand symtabs matching an optional regexp.
1593 Display the details of GDB configure-time options.
1595 maint set|show per-command
1596 maint set|show per-command space
1597 maint set|show per-command time
1598 maint set|show per-command symtab
1599 Enable display of per-command gdb resource usage.
1601 remove-symbol-file FILENAME
1602 remove-symbol-file -a ADDRESS
1603 Remove a symbol file added via add-symbol-file. The file to remove
1604 can be identified by its filename or by an address that lies within
1605 the boundaries of this symbol file in memory.
1608 info exceptions REGEXP
1609 Display the list of Ada exceptions defined in the program being
1610 debugged. If provided, only the exceptions whose names match REGEXP
1615 set debug symfile off|on
1617 Control display of debugging info regarding reading symbol files and
1618 symbol tables within those files
1620 set print raw frame-arguments
1621 show print raw frame-arguments
1622 Set/show whether to print frame arguments in raw mode,
1623 disregarding any defined pretty-printers.
1625 set remote trace-status-packet
1626 show remote trace-status-packet
1627 Set/show the use of remote protocol qTStatus packet.
1631 Control display of debugging messages related to Nios II targets.
1635 Control whether target-assisted range stepping is enabled.
1637 set startup-with-shell
1638 show startup-with-shell
1639 Specifies whether Unix child processes are started via a shell or
1644 Use the target memory cache for accesses to the code segment. This
1645 improves performance of remote debugging (particularly disassembly).
1647 * You can now use a literal value 'unlimited' for options that
1648 interpret 0 or -1 as meaning "unlimited". E.g., "set
1649 trace-buffer-size unlimited" is now an alias for "set
1650 trace-buffer-size -1" and "set height unlimited" is now an alias for
1653 * The "set debug symtab-create" debugging option of GDB has been changed to
1654 accept a verbosity level. 0 means "off", 1 provides basic debugging
1655 output, and values of 2 or greater provides more verbose output.
1657 * New command-line options
1659 Display the details of GDB configure-time options.
1661 * The command 'tsave' can now support new option '-ctf' to save trace
1662 buffer in Common Trace Format.
1664 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1667 * GDB now implements the the C++ 'typeid' operator.
1669 * The new convenience variable $_exception holds the exception being
1670 thrown or caught at an exception-related catchpoint.
1672 * The exception-related catchpoints, like "catch throw", now accept a
1673 regular expression which can be used to filter exceptions by type.
1675 * The new convenience variable $_exitsignal is automatically set to
1676 the terminating signal number when the program being debugged dies
1677 due to an uncaught signal.
1681 ** All MI commands now accept an optional "--language" option.
1682 Support for this feature can be verified by using the "-list-features"
1683 command, which should contain "language-option".
1685 ** The new command -info-gdb-mi-command allows the user to determine
1686 whether a GDB/MI command is supported or not.
1688 ** The "^error" result record returned when trying to execute an undefined
1689 GDB/MI command now provides a variable named "code" whose content is the
1690 "undefined-command" error code. Support for this feature can be verified
1691 by using the "-list-features" command, which should contain
1692 "undefined-command-error-code".
1694 ** The -trace-save MI command can optionally save trace buffer in Common
1697 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1699 ** The command -data-list-register-values now accepts an optional
1700 "--skip-unavailable" option. When used, only the available registers
1703 ** The new command -trace-frame-collected dumps collected variables,
1704 computed expressions, tvars, memory and registers in a traceframe.
1706 ** The commands -stack-list-locals, -stack-list-arguments and
1707 -stack-list-variables now accept an option "--skip-unavailable".
1708 When used, only the available locals or arguments are displayed.
1710 ** The -exec-run command now accepts an optional "--start" option.
1711 When used, the command follows the same semantics as the "start"
1712 command, stopping the program's execution at the start of its
1713 main subprogram. Support for this feature can be verified using
1714 the "-list-features" command, which should contain
1715 "exec-run-start-option".
1717 ** The new commands -catch-assert and -catch-exceptions insert
1718 catchpoints stopping the program when Ada exceptions are raised.
1720 ** The new command -info-ada-exceptions provides the equivalent of
1721 the new "info exceptions" command.
1723 * New system-wide configuration scripts
1724 A GDB installation now provides scripts suitable for use as system-wide
1725 configuration scripts for the following systems:
1729 * GDB now supports target-assigned range stepping with remote targets.
1730 This improves the performance of stepping source lines by reducing
1731 the number of control packets from/to GDB. See "New remote packets"
1734 * GDB now understands the element 'tvar' in the XML traceframe info.
1735 It has the id of the collected trace state variables.
1737 * On S/390 targets that provide the transactional-execution feature,
1738 the program interruption transaction diagnostic block (TDB) is now
1739 represented as a number of additional "registers" in GDB.
1741 * New remote packets
1745 The vCont packet supports a new 'r' action, that tells the remote
1746 stub to step through an address range itself, without GDB
1747 involvemement at each single-step.
1749 qXfer:libraries-svr4:read's annex
1750 The previously unused annex of the qXfer:libraries-svr4:read packet
1751 is now used to support passing an argument list. The remote stub
1752 reports support for this argument list to GDB's qSupported query.
1753 The defined arguments are "start" and "prev", used to reduce work
1754 necessary for library list updating, resulting in significant
1757 * New features in the GDB remote stub, GDBserver
1759 ** GDBserver now supports target-assisted range stepping. Currently
1760 enabled on x86/x86_64 GNU/Linux targets.
1762 ** GDBserver now adds element 'tvar' in the XML in the reply to
1763 'qXfer:traceframe-info:read'. It has the id of the collected
1764 trace state variables.
1766 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1769 * New 'z' formatter for printing and examining memory, this displays the
1770 value as hexadecimal zero padded on the left to the size of the type.
1772 * GDB can now use Windows x64 unwinding data.
1774 * The "set remotebaud" command has been replaced by "set serial baud".
1775 Similarly, "show remotebaud" has been replaced by "show serial baud".
1776 The "set remotebaud" and "show remotebaud" commands are still available
1777 to provide backward compatibility with older versions of GDB.
1779 *** Changes in GDB 7.6
1781 * Target record has been renamed to record-full.
1782 Record/replay is now enabled with the "record full" command.
1783 This also affects settings that are associated with full record/replay
1784 that have been moved from "set/show record" to "set/show record full":
1786 set|show record full insn-number-max
1787 set|show record full stop-at-limit
1788 set|show record full memory-query
1790 * A new record target "record-btrace" has been added. The new target
1791 uses hardware support to record the control-flow of a process. It
1792 does not support replaying the execution, but it implements the
1793 below new commands for investigating the recorded execution log.
1794 This new recording method can be enabled using:
1798 The "record-btrace" target is only available on Intel Atom processors
1799 and requires a Linux kernel 2.6.32 or later.
1801 * Two new commands have been added for record/replay to give information
1802 about the recorded execution without having to replay the execution.
1803 The commands are only supported by "record btrace".
1805 record instruction-history prints the execution history at
1806 instruction granularity
1808 record function-call-history prints the execution history at
1809 function granularity
1811 * New native configurations
1813 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1814 FreeBSD/powerpc powerpc*-*-freebsd
1815 x86_64/Cygwin x86_64-*-cygwin*
1816 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1820 ARM AArch64 aarch64*-*-elf
1821 ARM AArch64 GNU/Linux aarch64*-*-linux
1822 Lynx 178 PowerPC powerpc-*-lynx*178
1823 x86_64/Cygwin x86_64-*-cygwin*
1824 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1826 * If the configured location of system.gdbinit file (as given by the
1827 --with-system-gdbinit option at configure time) is in the
1828 data-directory (as specified by --with-gdb-datadir at configure
1829 time) or in one of its subdirectories, then GDB will look for the
1830 system-wide init file in the directory specified by the
1831 --data-directory command-line option.
1833 * New command line options:
1835 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1836 other initialization files, unlike -nx which disables all of them.
1838 * Removed command line options
1840 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1843 * The 'ptype' and 'whatis' commands now accept an argument to control
1846 * 'info proc' now works on some core files.
1850 ** Vectors can be created with gdb.Type.vector.
1852 ** Python's atexit.register now works in GDB.
1854 ** Types can be pretty-printed via a Python API.
1856 ** Python 3 is now supported (in addition to Python 2.4 or later)
1858 ** New class gdb.Architecture exposes GDB's internal representation
1859 of architecture in the Python API.
1861 ** New method Frame.architecture returns the gdb.Architecture object
1862 corresponding to the frame's architecture.
1864 * New Python-based convenience functions:
1866 ** $_memeq(buf1, buf2, length)
1867 ** $_streq(str1, str2)
1869 ** $_regex(str, regex)
1871 * The 'cd' command now defaults to using '~' (the home directory) if not
1874 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1875 default for GCC since November 2000.
1877 * The command 'forward-search' can now be abbreviated as 'fo'.
1879 * The command 'info tracepoints' can now display 'installed on target'
1880 or 'not installed on target' for each non-pending location of tracepoint.
1882 * New configure options
1884 --enable-libmcheck/--disable-libmcheck
1885 By default, development versions are built with -lmcheck on hosts
1886 that support it, in order to help track memory corruption issues.
1887 Release versions, on the other hand, are built without -lmcheck
1888 by default. The --enable-libmcheck/--disable-libmcheck configure
1889 options allow the user to override that default.
1890 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1891 This configure option allows the user to build GDB with
1892 libbabeltrace using which GDB can read Common Trace Format data.
1894 * New commands (for set/show, see "New options" below)
1897 Catch signals. This is similar to "handle", but allows commands and
1898 conditions to be attached.
1901 List the BFDs known to GDB.
1903 python-interactive [command]
1905 Start a Python interactive prompt, or evaluate the optional command
1906 and print the result of expressions.
1909 "py" is a new alias for "python".
1911 enable type-printer [name]...
1912 disable type-printer [name]...
1913 Enable or disable type printers.
1917 ** For the Renesas Super-H architecture, the "regs" command has been removed
1918 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1923 set print type methods (on|off)
1924 show print type methods
1925 Control whether method declarations are displayed by "ptype".
1926 The default is to show them.
1928 set print type typedefs (on|off)
1929 show print type typedefs
1930 Control whether typedef definitions are displayed by "ptype".
1931 The default is to show them.
1933 set filename-display basename|relative|absolute
1934 show filename-display
1935 Control the way in which filenames is displayed.
1936 The default is "relative", which preserves previous behavior.
1938 set trace-buffer-size
1939 show trace-buffer-size
1940 Request target to change the size of trace buffer.
1942 set remote trace-buffer-size-packet auto|on|off
1943 show remote trace-buffer-size-packet
1944 Control the use of the remote protocol `QTBuffer:size' packet.
1948 Control display of debugging messages related to ARM AArch64.
1951 set debug coff-pe-read
1952 show debug coff-pe-read
1953 Control display of debugging messages related to reading of COFF/PE
1958 Control display of debugging messages related to Mach-O symbols
1961 set debug notification
1962 show debug notification
1963 Control display of debugging info for async remote notification.
1967 ** Command parameter changes are now notified using new async record
1968 "=cmd-param-changed".
1969 ** Trace frame changes caused by command "tfind" are now notified using
1970 new async record "=traceframe-changed".
1971 ** The creation, deletion and modification of trace state variables
1972 are now notified using new async records "=tsv-created",
1973 "=tsv-deleted" and "=tsv-modified".
1974 ** The start and stop of process record are now notified using new
1975 async record "=record-started" and "=record-stopped".
1976 ** Memory changes are now notified using new async record
1978 ** The data-disassemble command response will include a "fullname" field
1979 containing the absolute file name when source has been requested.
1980 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1981 command, to allow pattern filling of memory areas.
1982 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1983 library load/unload events.
1984 ** The response to breakpoint commands and breakpoint async records
1985 includes an "installed" field containing a boolean state about each
1986 non-pending tracepoint location is whether installed on target or not.
1987 ** Output of the "-trace-status" command includes a "trace-file" field
1988 containing the name of the trace file being examined. This field is
1989 optional, and only present when examining a trace file.
1990 ** The "fullname" field is now always present along with the "file" field,
1991 even if the file cannot be found by GDB.
1993 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1994 You must have the LZMA library available when configuring GDB for this
1995 feature to be enabled. For more information, see:
1996 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1998 * New remote packets
2001 Set the size of trace buffer. The remote stub reports support for this
2002 packet to gdb's qSupported query.
2005 Enable Branch Trace Store (BTS)-based branch tracing for the current
2006 thread. The remote stub reports support for this packet to gdb's
2010 Disable branch tracing for the current thread. The remote stub reports
2011 support for this packet to gdb's qSupported query.
2014 Read the traced branches for the current thread. The remote stub
2015 reports support for this packet to gdb's qSupported query.
2017 *** Changes in GDB 7.5
2019 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2020 for more x32 ABI info.
2022 * GDB now supports access to MIPS DSP registers on Linux targets.
2024 * GDB now supports debugging microMIPS binaries.
2026 * The "info os" command on GNU/Linux can now display information on
2027 several new classes of objects managed by the operating system:
2028 "info os procgroups" lists process groups
2029 "info os files" lists file descriptors
2030 "info os sockets" lists internet-domain sockets
2031 "info os shm" lists shared-memory regions
2032 "info os semaphores" lists semaphores
2033 "info os msg" lists message queues
2034 "info os modules" lists loaded kernel modules
2036 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2037 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2038 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2039 options and inspect the probe arguments using the new $_probe_arg family
2040 of convenience variables. You can obtain more information about SystemTap
2041 in <http://sourceware.org/systemtap/>.
2043 * GDB now supports reversible debugging on ARM, it allows you to
2044 debug basic ARM and THUMB instructions, and provides
2045 record/replay support.
2047 * The option "symbol-reloading" has been deleted as it is no longer used.
2051 ** GDB commands implemented in Python can now be put in command class
2054 ** The "maint set python print-stack on|off" is now deleted.
2056 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2057 apply "flag enum"-style pretty-printing to any enum.
2059 ** gdb.lookup_symbol can now work when there is no current frame.
2061 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2062 the source at which the symbol was defined.
2064 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2065 method 'value'. The former indicates whether the symbol needs a
2066 frame in order to compute its value, and the latter computes the
2069 ** A new method 'referenced_value' on gdb.Value objects which can
2070 dereference pointer as well as C++ reference values.
2072 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2073 which return the global and static blocks (as gdb.Block objects),
2074 of the underlying symbol table, respectively.
2076 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2077 object associated with a PC value.
2079 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2080 of the address range occupied by code for the current source line.
2082 * Go language support.
2083 GDB now supports debugging programs written in the Go programming
2086 * GDBserver now supports stdio connections.
2087 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2089 * The binary "gdbtui" can no longer be built or installed.
2090 Use "gdb -tui" instead.
2092 * GDB will now print "flag" enums specially. A flag enum is one where
2093 all the enumerator values have no bits in common when pairwise
2094 "and"ed. When printing a value whose type is a flag enum, GDB will
2095 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2096 (gdb) print (enum E) 3
2099 * The filename part of a linespec will now match trailing components
2100 of a source file name. For example, "break gcc/expr.c:1000" will
2101 now set a breakpoint in build/gcc/expr.c, but not
2102 build/libcpp/expr.c.
2104 * The "info proc" and "generate-core-file" commands will now also
2105 work on remote targets connected to GDBserver on Linux.
2107 * The command "info catch" has been removed. It has been disabled
2108 since December 2007.
2110 * The "catch exception" and "catch assert" commands now accept
2111 a condition at the end of the command, much like the "break"
2112 command does. For instance:
2114 (gdb) catch exception Constraint_Error if Barrier = True
2116 Previously, it was possible to add a condition to such catchpoints,
2117 but it had to be done as a second step, after the catchpoint had been
2118 created, using the "condition" command.
2120 * The "info static-tracepoint-marker" command will now also work on
2121 native Linux targets with in-process agent.
2123 * GDB can now set breakpoints on inlined functions.
2125 * The .gdb_index section has been updated to include symbols for
2126 inlined functions. GDB will ignore older .gdb_index sections by
2127 default, which could cause symbol files to be loaded more slowly
2128 until their .gdb_index sections can be recreated. The new command
2129 "set use-deprecated-index-sections on" will cause GDB to use any older
2130 .gdb_index sections it finds. This will restore performance, but the
2131 ability to set breakpoints on inlined functions will be lost in symbol
2132 files with older .gdb_index sections.
2134 The .gdb_index section has also been updated to record more information
2135 about each symbol. This speeds up the "info variables", "info functions"
2136 and "info types" commands when used with programs having the .gdb_index
2137 section, as well as speeding up debugging with shared libraries using
2138 the .gdb_index section.
2140 * Ada support for GDB/MI Variable Objects has been added.
2142 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2147 ** New command -info-os is the MI equivalent of "info os".
2149 ** Output logs ("set logging" and related) now include MI output.
2153 ** "set use-deprecated-index-sections on|off"
2154 "show use-deprecated-index-sections on|off"
2155 Controls the use of deprecated .gdb_index sections.
2157 ** "catch load" and "catch unload" can be used to stop when a shared
2158 library is loaded or unloaded, respectively.
2160 ** "enable count" can be used to auto-disable a breakpoint after
2163 ** "info vtbl" can be used to show the virtual method tables for
2164 C++ and Java objects.
2166 ** "explore" and its sub commands "explore value" and "explore type"
2167 can be used to recursively explore values and types of
2168 expressions. These commands are available only if GDB is
2169 configured with '--with-python'.
2171 ** "info auto-load" shows status of all kinds of auto-loaded files,
2172 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2173 sequences of commands files, "info auto-load python-scripts"
2174 shows status of auto-loading Python script files,
2175 "info auto-load local-gdbinit" shows status of loading init file
2176 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2177 status of inferior specific thread debugging shared library loading.
2179 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2180 and "show auto-load-scripts" commands have been deprecated, use their
2181 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2182 and "show auto-load python-scripts" counterparts instead.
2184 ** "dprintf location,format,args..." creates a dynamic printf, which
2185 is basically a breakpoint that does a printf and immediately
2186 resumes your program's execution, so it is like a printf that you
2187 can insert dynamically at runtime instead of at compiletime.
2189 ** "set print symbol"
2191 Controls whether GDB attempts to display the symbol, if any,
2192 corresponding to addresses it prints. This defaults to "on", but
2193 you can set it to "off" to restore GDB's previous behavior.
2195 * Deprecated commands
2197 ** For the Renesas Super-H architecture, the "regs" command has been
2198 deprecated, and "info all-registers" should be used instead.
2202 Renesas RL78 rl78-*-elf
2203 HP OpenVMS ia64 ia64-hp-openvms*
2205 * GDBserver supports evaluation of breakpoint conditions. When
2206 support is advertised by GDBserver, GDB may be told to send the
2207 breakpoint conditions in bytecode form to GDBserver. GDBserver
2208 will only report the breakpoint trigger to GDB when its condition
2213 set mips compression
2214 show mips compression
2215 Select the compressed ISA encoding used in functions that have no symbol
2216 information available. The encoding can be set to either of:
2219 and is updated automatically from ELF file flags if available.
2221 set breakpoint condition-evaluation
2222 show breakpoint condition-evaluation
2223 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2224 GDBserver ("target"). Default option "auto" chooses the most efficient
2226 This option can improve debugger efficiency depending on the speed of the
2230 Disable auto-loading globally.
2233 Show auto-loading setting of all kinds of auto-loaded files.
2235 set auto-load gdb-scripts on|off
2236 show auto-load gdb-scripts
2237 Control auto-loading of GDB canned sequences of commands files.
2239 set auto-load python-scripts on|off
2240 show auto-load python-scripts
2241 Control auto-loading of Python script files.
2243 set auto-load local-gdbinit on|off
2244 show auto-load local-gdbinit
2245 Control loading of init file (.gdbinit) from current directory.
2247 set auto-load libthread-db on|off
2248 show auto-load libthread-db
2249 Control auto-loading of inferior specific thread debugging shared library.
2251 set auto-load scripts-directory <dir1>[:<dir2>...]
2252 show auto-load scripts-directory
2253 Set a list of directories from which to load auto-loaded scripts.
2254 Automatically loaded Python scripts and GDB scripts are located in one
2255 of the directories listed by this option.
2256 The delimiter (':' above) may differ according to the host platform.
2258 set auto-load safe-path <dir1>[:<dir2>...]
2259 show auto-load safe-path
2260 Set a list of directories from which it is safe to auto-load files.
2261 The delimiter (':' above) may differ according to the host platform.
2263 set debug auto-load on|off
2264 show debug auto-load
2265 Control display of debugging info for auto-loading the files above.
2267 set dprintf-style gdb|call|agent
2269 Control the way in which a dynamic printf is performed; "gdb"
2270 requests a GDB printf command, while "call" causes dprintf to call a
2271 function in the inferior. "agent" requests that the target agent
2272 (such as GDBserver) do the printing.
2274 set dprintf-function <expr>
2275 show dprintf-function
2276 set dprintf-channel <expr>
2277 show dprintf-channel
2278 Set the function and optional first argument to the call when using
2279 the "call" style of dynamic printf.
2281 set disconnected-dprintf on|off
2282 show disconnected-dprintf
2283 Control whether agent-style dynamic printfs continue to be in effect
2284 after GDB disconnects.
2286 * New configure options
2288 --with-auto-load-dir
2289 Configure default value for the 'set auto-load scripts-directory'
2290 setting above. It defaults to '$debugdir:$datadir/auto-load',
2291 $debugdir representing global debugging info directories (available
2292 via 'show debug-file-directory') and $datadir representing GDB's data
2293 directory (available via 'show data-directory').
2295 --with-auto-load-safe-path
2296 Configure default value for the 'set auto-load safe-path' setting
2297 above. It defaults to the --with-auto-load-dir setting.
2299 --without-auto-load-safe-path
2300 Set 'set auto-load safe-path' to '/', effectively disabling this
2303 * New remote packets
2305 z0/z1 conditional breakpoints extension
2307 The z0/z1 breakpoint insertion packets have been extended to carry
2308 a list of conditional expressions over to the remote stub depending on the
2309 condition evaluation mode. The use of this extension can be controlled
2310 via the "set remote conditional-breakpoints-packet" command.
2314 Specify the signals which the remote stub may pass to the debugged
2315 program without GDB involvement.
2317 * New command line options
2319 --init-command=FILE, -ix Like --command, -x but execute it
2320 before loading inferior.
2321 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2322 execute it before loading inferior.
2324 *** Changes in GDB 7.4
2326 * GDB now handles ambiguous linespecs more consistently; the existing
2327 FILE:LINE support has been expanded to other types of linespecs. A
2328 breakpoint will now be set on all matching locations in all
2329 inferiors, and locations will be added or removed according to
2332 * GDB now allows you to skip uninteresting functions and files when
2333 stepping with the "skip function" and "skip file" commands.
2335 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2336 and "show remote hardware-watchpoint-length-limit". These allows to
2337 set or show the maximum length limit (in bytes) of a remote
2338 target hardware watchpoint.
2340 This allows e.g. to use "unlimited" hardware watchpoints with the
2341 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2342 watchpoints are slower than real hardware watchpoints but are
2343 significantly faster than gdb software watchpoints.
2347 ** The register_pretty_printer function in module gdb.printing now takes
2348 an optional `replace' argument. If True, the new printer replaces any
2351 ** The "maint set python print-stack on|off" command has been
2352 deprecated and will be deleted in GDB 7.5.
2353 A new command: "set python print-stack none|full|message" has
2354 replaced it. Additionally, the default for "print-stack" is
2355 now "message", which just prints the error message without
2358 ** A prompt substitution hook (prompt_hook) is now available to the
2361 ** A new Python module, gdb.prompt has been added to the GDB Python
2362 modules library. This module provides functionality for
2363 escape sequences in prompts (used by set/show
2364 extended-prompt). These escape sequences are replaced by their
2365 corresponding value.
2367 ** Python commands and convenience-functions located in
2368 'data-directory'/python/gdb/command and
2369 'data-directory'/python/gdb/function are now automatically loaded
2372 ** Blocks now provide four new attributes. global_block and
2373 static_block will return the global and static blocks
2374 respectively. is_static and is_global are boolean attributes
2375 that indicate if the block is one of those two types.
2377 ** Symbols now provide the "type" attribute, the type of the symbol.
2379 ** The "gdb.breakpoint" function has been deprecated in favor of
2382 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2383 of a function. This class is based on the "finish" command
2384 available in the CLI.
2386 ** Type objects for struct and union types now allow access to
2387 the fields using standard Python dictionary (mapping) methods.
2388 For example, "some_type['myfield']" now works, as does
2389 "some_type.items()".
2391 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2394 ** A new function, "deep_items" has been added to the gdb.types
2395 module in the GDB Python modules library. This function returns
2396 an iterator over the fields of a struct or union type. Unlike
2397 the standard Python "iteritems" method, it will recursively traverse
2398 any anonymous fields.
2402 ** "*stopped" events can report several new "reason"s, such as
2405 ** Breakpoint changes are now notified using new async records, like
2406 "=breakpoint-modified".
2408 ** New command -ada-task-info.
2410 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2411 $sdir specifies the default system locations of shared libraries.
2412 $pdir specifies the directory where the libpthread used by the application
2415 GDB no longer looks in $sdir and $pdir after it has searched the directories
2416 mentioned in libthread-db-search-path. If you want to search those
2417 directories, they must be specified in libthread-db-search-path.
2418 The default value of libthread-db-search-path on GNU/Linux and Solaris
2419 systems is now "$sdir:$pdir".
2421 $pdir is not supported by gdbserver, it is currently ignored.
2422 $sdir is supported by gdbserver.
2424 * New configure option --with-iconv-bin.
2425 When using the internationalization support like the one in the GNU C
2426 library, GDB will invoke the "iconv" program to get a list of supported
2427 character sets. If this program lives in a non-standard location, one can
2428 use this option to specify where to find it.
2430 * When natively debugging programs on PowerPC BookE processors running
2431 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2432 watchpoints, which specify a mask in addition to an address to watch.
2433 The mask specifies that some bits of an address (the bits which are
2434 reset in the mask) should be ignored when matching the address accessed
2435 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2436 section in the user manual for more details.
2438 * The new option --once causes GDBserver to stop listening for connections once
2439 the first connection is made. The listening port used by GDBserver will
2440 become available after that.
2442 * New commands "info macros" and "alias" have been added.
2444 * New function parameters suffix @entry specifies value of function parameter
2445 at the time the function got called. Entry values are available only since
2451 "!" is now an alias of the "shell" command.
2452 Note that no space is needed between "!" and SHELL COMMAND.
2456 watch EXPRESSION mask MASK_VALUE
2457 The watch command now supports the mask argument which allows creation
2458 of masked watchpoints, if the current architecture supports this feature.
2460 info auto-load-scripts [REGEXP]
2461 This command was formerly named "maintenance print section-scripts".
2462 It is now generally useful and is no longer a maintenance-only command.
2464 info macro [-all] [--] MACRO
2465 The info macro command has new options `-all' and `--'. The first for
2466 printing all definitions of a macro. The second for explicitly specifying
2467 the end of arguments and the beginning of the macro name in case the macro
2468 name starts with a hyphen.
2470 collect[/s] EXPRESSIONS
2471 The tracepoint collect command now takes an optional modifier "/s"
2472 that directs it to dereference pointer-to-character types and
2473 collect the bytes of memory up to a zero byte. The behavior is
2474 similar to what you see when you use the regular print command on a
2475 string. An optional integer following the "/s" sets a bound on the
2476 number of bytes that will be collected.
2479 The trace start command now interprets any supplied arguments as a
2480 note to be recorded with the trace run, with an effect similar to
2481 setting the variable trace-notes.
2484 The trace stop command now interprets any arguments as a note to be
2485 mentioned along with the tstatus report that the trace was stopped
2486 with a command. The effect is similar to setting the variable
2489 * Tracepoints can now be enabled and disabled at any time after a trace
2490 experiment has been started using the standard "enable" and "disable"
2491 commands. It is now possible to start a trace experiment with no enabled
2492 tracepoints; GDB will display a warning, but will allow the experiment to
2493 begin, assuming that tracepoints will be enabled as needed while the trace
2496 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2497 locations with 4-byte instructions, when they were previously
2498 limited to locations with instructions of 5 bytes or longer.
2502 set debug dwarf2-read
2503 show debug dwarf2-read
2504 Turns on or off display of debugging messages related to reading
2505 DWARF debug info. The default is off.
2507 set debug symtab-create
2508 show debug symtab-create
2509 Turns on or off display of debugging messages related to symbol table
2510 creation. The default is off.
2513 show extended-prompt
2514 Set the GDB prompt, and allow escape sequences to be inserted to
2515 display miscellaneous information (see 'help set extended-prompt'
2516 for the list of sequences). This prompt (and any information
2517 accessed through the escape sequences) is updated every time the
2518 prompt is displayed.
2520 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2521 show print entry-values
2522 Set printing of frame argument values at function entry. In some cases
2523 GDB can determine the value of function argument which was passed by the
2524 function caller, even if the value was modified inside the called function.
2526 set debug entry-values
2527 show debug entry-values
2528 Control display of debugging info for determining frame argument values at
2529 function entry and virtual tail call frames.
2531 set basenames-may-differ
2532 show basenames-may-differ
2533 Set whether a source file may have multiple base names.
2534 (A "base name" is the name of a file with the directory part removed.
2535 Example: The base name of "/home/user/hello.c" is "hello.c".)
2536 If set, GDB will canonicalize file names (e.g., expand symlinks)
2537 before comparing them. Canonicalization is an expensive operation,
2538 but it allows the same file be known by more than one base name.
2539 If not set (the default), all source files are assumed to have just
2540 one base name, and gdb will do file name comparisons more efficiently.
2546 Set a user name and notes for the current and any future trace runs.
2547 This is useful for long-running and/or disconnected traces, to
2548 inform others (or yourself) as to who is running the trace, supply
2549 contact information, or otherwise explain what is going on.
2551 set trace-stop-notes
2552 show trace-stop-notes
2553 Set a note attached to the trace run, that is displayed when the
2554 trace has been stopped by a tstop command. This is useful for
2555 instance as an explanation, if you are stopping a trace run that was
2556 started by someone else.
2558 * New remote packets
2562 Dynamically enable a tracepoint in a started trace experiment.
2566 Dynamically disable a tracepoint in a started trace experiment.
2570 Set the user and notes of the trace run.
2574 Query the current status of a tracepoint.
2578 Query the minimum length of instruction at which a fast tracepoint may
2581 * Dcache size (number of lines) and line-size are now runtime-configurable
2582 via "set dcache line" and "set dcache line-size" commands.
2586 Texas Instruments TMS320C6x tic6x-*-*
2590 Renesas RL78 rl78-*-elf
2592 *** Changes in GDB 7.3.1
2594 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2596 *** Changes in GDB 7.3
2598 * GDB has a new command: "thread find [REGEXP]".
2599 It finds the thread id whose name, target id, or thread extra info
2600 matches the given regular expression.
2602 * The "catch syscall" command now works on mips*-linux* targets.
2604 * The -data-disassemble MI command now supports modes 2 and 3 for
2605 dumping the instruction opcodes.
2607 * New command line options
2609 -data-directory DIR Specify DIR as the "data-directory".
2610 This is mostly for testing purposes.
2612 * The "maint set python auto-load on|off" command has been renamed to
2613 "set auto-load-scripts on|off".
2615 * GDB has a new command: "set directories".
2616 It is like the "dir" command except that it replaces the
2617 source path list instead of augmenting it.
2619 * GDB now understands thread names.
2621 On GNU/Linux, "info threads" will display the thread name as set by
2622 prctl or pthread_setname_np.
2624 There is also a new command, "thread name", which can be used to
2625 assign a name internally for GDB to display.
2628 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2629 has been integrated into GDB.
2633 ** The function gdb.Write now accepts an optional keyword 'stream'.
2634 This keyword, when provided, will direct the output to either
2635 stdout, stderr, or GDB's logging output.
2637 ** Parameters can now be be sub-classed in Python, and in particular
2638 you may implement the get_set_doc and get_show_doc functions.
2639 This improves how Parameter set/show documentation is processed
2640 and allows for more dynamic content.
2642 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2643 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2644 have an is_valid method.
2646 ** Breakpoints can now be sub-classed in Python, and in particular
2647 you may implement a 'stop' function that is executed each time
2648 the inferior reaches that breakpoint.
2650 ** New function gdb.lookup_global_symbol looks up a global symbol.
2652 ** GDB values in Python are now callable if the value represents a
2653 function. For example, if 'some_value' represents a function that
2654 takes two integer parameters and returns a value, you can call
2655 that function like so:
2657 result = some_value (10,20)
2659 ** Module gdb.types has been added.
2660 It contains a collection of utilities for working with gdb.Types objects:
2661 get_basic_type, has_field, make_enum_dict.
2663 ** Module gdb.printing has been added.
2664 It contains utilities for writing and registering pretty-printers.
2665 New classes: PrettyPrinter, SubPrettyPrinter,
2666 RegexpCollectionPrettyPrinter.
2667 New function: register_pretty_printer.
2669 ** New commands "info pretty-printers", "enable pretty-printer" and
2670 "disable pretty-printer" have been added.
2672 ** gdb.parameter("directories") is now available.
2674 ** New function gdb.newest_frame returns the newest frame in the
2677 ** The gdb.InferiorThread class has a new "name" attribute. This
2678 holds the thread's name.
2680 ** Python Support for Inferior events.
2681 Python scripts can add observers to be notified of events
2682 occurring in the process being debugged.
2683 The following events are currently supported:
2684 - gdb.events.cont Continue event.
2685 - gdb.events.exited Inferior exited event.
2686 - gdb.events.stop Signal received, and Breakpoint hit events.
2690 ** GDB now puts template parameters in scope when debugging in an
2691 instantiation. For example, if you have:
2693 template<int X> int func (void) { return X; }
2695 then if you step into func<5>, "print X" will show "5". This
2696 feature requires proper debuginfo support from the compiler; it
2697 was added to GCC 4.5.
2699 ** The motion commands "next", "finish", "until", and "advance" now
2700 work better when exceptions are thrown. In particular, GDB will
2701 no longer lose control of the inferior; instead, the GDB will
2702 stop the inferior at the point at which the exception is caught.
2703 This functionality requires a change in the exception handling
2704 code that was introduced in GCC 4.5.
2706 * GDB now follows GCC's rules on accessing volatile objects when
2707 reading or writing target state during expression evaluation.
2708 One notable difference to prior behavior is that "print x = 0"
2709 no longer generates a read of x; the value of the assignment is
2710 now always taken directly from the value being assigned.
2712 * GDB now has some support for using labels in the program's source in
2713 linespecs. For instance, you can use "advance label" to continue
2714 execution to a label.
2716 * GDB now has support for reading and writing a new .gdb_index
2717 section. This section holds a fast index of DWARF debugging
2718 information and can be used to greatly speed up GDB startup and
2719 operation. See the documentation for `save gdb-index' for details.
2721 * The "watch" command now accepts an optional "-location" argument.
2722 When used, this causes GDB to watch the memory referred to by the
2723 expression. Such a watchpoint is never deleted due to it going out
2726 * GDB now supports thread debugging of core dumps on GNU/Linux.
2728 GDB now activates thread debugging using the libthread_db library
2729 when debugging GNU/Linux core dumps, similarly to when debugging
2730 live processes. As a result, when debugging a core dump file, GDB
2731 is now able to display pthread_t ids of threads. For example, "info
2732 threads" shows the same output as when debugging the process when it
2733 was live. In earlier releases, you'd see something like this:
2736 * 1 LWP 6780 main () at main.c:10
2738 While now you see this:
2741 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2743 It is also now possible to inspect TLS variables when debugging core
2746 When debugging a core dump generated on a machine other than the one
2747 used to run GDB, you may need to point GDB at the correct
2748 libthread_db library with the "set libthread-db-search-path"
2749 command. See the user manual for more details on this command.
2751 * When natively debugging programs on PowerPC BookE processors running
2752 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2753 which stop execution of the inferior whenever it executes an instruction
2754 at any address within the specified range. See the "PowerPC Embedded"
2755 section in the user manual for more details.
2757 * New features in the GDB remote stub, GDBserver
2759 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2760 and i686 LynxOS (version 5.x).
2762 ** GDBserver is now supported on Blackfin Linux.
2764 * New native configurations
2766 ia64 HP-UX ia64-*-hpux*
2770 Analog Devices, Inc. Blackfin Processor bfin-*
2772 * Ada task switching is now supported on sparc-elf targets when
2773 debugging a program using the Ravenscar Profile. For more information,
2774 see the "Tasking Support when using the Ravenscar Profile" section
2775 in the GDB user manual.
2777 * Guile support was removed.
2779 * New features in the GNU simulator
2781 ** The --map-info flag lists all known core mappings.
2783 ** CFI flashes may be simulated via the "cfi" device.
2785 *** Changes in GDB 7.2
2787 * Shared library support for remote targets by default
2789 When GDB is configured for a generic, non-OS specific target, like
2790 for example, --target=arm-eabi or one of the many *-*-elf targets,
2791 GDB now queries remote stubs for loaded shared libraries using the
2792 `qXfer:libraries:read' packet. Previously, shared library support
2793 was always disabled for such configurations.
2797 ** Argument Dependent Lookup (ADL)
2799 In C++ ADL lookup directs function search to the namespaces of its
2800 arguments even if the namespace has not been imported.
2810 Here the compiler will search for `foo' in the namespace of 'b'
2811 and find A::foo. GDB now supports this. This construct is commonly
2812 used in the Standard Template Library for operators.
2814 ** Improved User Defined Operator Support
2816 In addition to member operators, GDB now supports lookup of operators
2817 defined in a namespace and imported with a `using' directive, operators
2818 defined in the global scope, operators imported implicitly from an
2819 anonymous namespace, and the ADL operators mentioned in the previous
2821 GDB now also supports proper overload resolution for all the previously
2822 mentioned flavors of operators.
2824 ** static const class members
2826 Printing of static const class members that are initialized in the
2827 class definition has been fixed.
2829 * Windows Thread Information Block access.
2831 On Windows targets, GDB now supports displaying the Windows Thread
2832 Information Block (TIB) structure. This structure is visible either
2833 by using the new command `info w32 thread-information-block' or, by
2834 dereferencing the new convenience variable named `$_tlb', a
2835 thread-specific pointer to the TIB. This feature is also supported
2836 when remote debugging using GDBserver.
2838 * Static tracepoints
2840 Static tracepoints are calls in the user program into a tracing
2841 library. One such library is a port of the LTTng kernel tracer to
2842 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2843 When debugging with GDBserver, GDB now supports combining the GDB
2844 tracepoint machinery with such libraries. For example: the user can
2845 use GDB to probe a static tracepoint marker (a call from the user
2846 program into the tracing library) with the new "strace" command (see
2847 "New commands" below). This creates a "static tracepoint" in the
2848 breakpoint list, that can be manipulated with the same feature set
2849 as fast and regular tracepoints. E.g., collect registers, local and
2850 global variables, collect trace state variables, and define
2851 tracepoint conditions. In addition, the user can collect extra
2852 static tracepoint marker specific data, by collecting the new
2853 $_sdata internal variable. When analyzing the trace buffer, you can
2854 inspect $_sdata like any other variable available to GDB. For more
2855 information, see the "Tracepoints" chapter in GDB user manual. New
2856 remote packets have been defined to support static tracepoints, see
2857 the "New remote packets" section below.
2859 * Better reconstruction of tracepoints after disconnected tracing
2861 GDB will attempt to download the original source form of tracepoint
2862 definitions when starting a trace run, and then will upload these
2863 upon reconnection to the target, resulting in a more accurate
2864 reconstruction of the tracepoints that are in use on the target.
2868 You can now exercise direct control over the ways that GDB can
2869 affect your program. For instance, you can disallow the setting of
2870 breakpoints, so that the program can run continuously (assuming
2871 non-stop mode). In addition, the "observer" variable is available
2872 to switch all of the different controls; in observer mode, GDB
2873 cannot affect the target's behavior at all, which is useful for
2874 tasks like diagnosing live systems in the field.
2876 * The new convenience variable $_thread holds the number of the
2879 * New remote packets
2883 Return the address of the Windows Thread Information Block of a given thread.
2887 In response to several of the tracepoint packets, the target may now
2888 also respond with a number of intermediate `qRelocInsn' request
2889 packets before the final result packet, to have GDB handle
2890 relocating an instruction to execute at a different address. This
2891 is particularly useful for stubs that support fast tracepoints. GDB
2892 reports support for this feature in the qSupported packet.
2896 List static tracepoint markers in the target program.
2900 List static tracepoint markers at a given address in the target
2903 qXfer:statictrace:read
2905 Read the static trace data collected (by a `collect $_sdata'
2906 tracepoint action). The remote stub reports support for this packet
2907 to gdb's qSupported query.
2911 Send the current settings of GDB's permission flags.
2915 Send part of the source (textual) form of a tracepoint definition,
2916 which includes location, conditional, and action list.
2918 * The source command now accepts a -s option to force searching for the
2919 script in the source search path even if the script name specifies
2922 * New features in the GDB remote stub, GDBserver
2924 - GDBserver now support tracepoints (including fast tracepoints, and
2925 static tracepoints). The feature is currently supported by the
2926 i386-linux and amd64-linux builds. See the "Tracepoints support
2927 in gdbserver" section in the manual for more information.
2929 GDBserver JIT compiles the tracepoint's conditional agent
2930 expression bytecode into native code whenever possible for low
2931 overhead dynamic tracepoints conditionals. For such tracepoints,
2932 an expression that examines program state is evaluated when the
2933 tracepoint is reached, in order to determine whether to capture
2934 trace data. If the condition is simple and false, processing the
2935 tracepoint finishes very quickly and no data is gathered.
2937 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2938 for static tracepoints support.
2940 - GDBserver now supports x86_64 Windows 64-bit debugging.
2942 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2943 it understands register description.
2945 * The --batch flag now disables pagination and queries.
2947 * X86 general purpose registers
2949 GDB now supports reading/writing byte, word and double-word x86
2950 general purpose registers directly. This means you can use, say,
2951 $ah or $ax to refer, respectively, to the byte register AH and
2952 16-bit word register AX that are actually portions of the 32-bit
2953 register EAX or 64-bit register RAX.
2955 * The `commands' command now accepts a range of breakpoints to modify.
2956 A plain `commands' following a command that creates multiple
2957 breakpoints affects all the breakpoints set by that command. This
2958 applies to breakpoints set by `rbreak', and also applies when a
2959 single `break' command creates multiple breakpoints (e.g.,
2960 breakpoints on overloaded c++ functions).
2962 * The `rbreak' command now accepts a filename specification as part of
2963 its argument, limiting the functions selected by the regex to those
2964 in the specified file.
2966 * Support for remote debugging Windows and SymbianOS shared libraries
2967 from Unix hosts has been improved. Non Windows GDB builds now can
2968 understand target reported file names that follow MS-DOS based file
2969 system semantics, such as file names that include drive letters and
2970 use the backslash character as directory separator. This makes it
2971 possible to transparently use the "set sysroot" and "set
2972 solib-search-path" on Unix hosts to point as host copies of the
2973 target's shared libraries. See the new command "set
2974 target-file-system-kind" described below, and the "Commands to
2975 specify files" section in the user manual for more information.
2979 eval template, expressions...
2980 Convert the values of one or more expressions under the control
2981 of the string template to a command line, and call it.
2983 set target-file-system-kind unix|dos-based|auto
2984 show target-file-system-kind
2985 Set or show the assumed file system kind for target reported file
2988 save breakpoints <filename>
2989 Save all current breakpoint definitions to a file suitable for use
2990 in a later debugging session. To read the saved breakpoint
2991 definitions, use the `source' command.
2993 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2996 info static-tracepoint-markers
2997 Display information about static tracepoint markers in the target.
2999 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3000 Define a static tracepoint by probing a marker at the given
3001 function, line, address, or marker ID.
3005 Enable and disable observer mode.
3007 set may-write-registers on|off
3008 set may-write-memory on|off
3009 set may-insert-breakpoints on|off
3010 set may-insert-tracepoints on|off
3011 set may-insert-fast-tracepoints on|off
3012 set may-interrupt on|off
3013 Set individual permissions for GDB effects on the target. Note that
3014 some of these settings can have undesirable or surprising
3015 consequences, particularly when changed in the middle of a session.
3016 For instance, disabling the writing of memory can prevent
3017 breakpoints from being inserted, cause single-stepping to fail, or
3018 even crash your program, if you disable after breakpoints have been
3019 inserted. However, GDB should not crash.
3021 set record memory-query on|off
3022 show record memory-query
3023 Control whether to stop the inferior if memory changes caused
3024 by an instruction cannot be recorded.
3029 The disassemble command now supports "start,+length" form of two arguments.
3033 ** GDB now provides a new directory location, called the python directory,
3034 where Python scripts written for GDB can be installed. The location
3035 of that directory is <data-directory>/python, where <data-directory>
3036 is the GDB data directory. For more details, see section `Scripting
3037 GDB using Python' in the manual.
3039 ** The GDB Python API now has access to breakpoints, symbols, symbol
3040 tables, program spaces, inferiors, threads and frame's code blocks.
3041 Additionally, GDB Parameters can now be created from the API, and
3042 manipulated via set/show in the CLI.
3044 ** New functions gdb.target_charset, gdb.target_wide_charset,
3045 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3047 ** New exception gdb.GdbError.
3049 ** Pretty-printers are now also looked up in the current program space.
3051 ** Pretty-printers can now be individually enabled and disabled.
3053 ** GDB now looks for names of Python scripts to auto-load in a
3054 special section named `.debug_gdb_scripts', in addition to looking
3055 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3057 * Tracepoint actions were unified with breakpoint commands. In particular,
3058 there are no longer differences in "info break" output for breakpoints and
3059 tracepoints and the "commands" command can be used for both tracepoints and
3060 regular breakpoints.
3064 ARM Symbian arm*-*-symbianelf*
3066 * D language support.
3067 GDB now supports debugging programs written in the D programming
3070 * GDB now supports the extended ptrace interface for PowerPC which is
3071 available since Linux kernel version 2.6.34. This automatically enables
3072 any hardware breakpoints and additional hardware watchpoints available in
3073 the processor. The old ptrace interface exposes just one hardware
3074 watchpoint and no hardware breakpoints.
3076 * GDB is now able to use the Data Value Compare (DVC) register available on
3077 embedded PowerPC processors to implement in hardware simple watchpoint
3078 conditions of the form:
3080 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3082 This works in native GDB running on Linux kernels with the extended ptrace
3083 interface mentioned above.
3085 *** Changes in GDB 7.1
3089 ** Namespace Support
3091 GDB now supports importing of namespaces in C++. This enables the
3092 user to inspect variables from imported namespaces. Support for
3093 namepace aliasing has also been added. So, if a namespace is
3094 aliased in the current scope (e.g. namepace C=A; ) the user can
3095 print variables using the alias (e.g. (gdb) print C::x).
3099 All known bugs relating to the printing of virtual base class were
3100 fixed. It is now possible to call overloaded static methods using a
3105 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3106 and reinterpret_cast<> are now handled by the C++ expression parser.
3110 Xilinx MicroBlaze microblaze-*-*
3115 Xilinx MicroBlaze microblaze
3118 * Multi-program debugging.
3120 GDB now has support for multi-program (a.k.a. multi-executable or
3121 multi-exec) debugging. This allows for debugging multiple inferiors
3122 simultaneously each running a different program under the same GDB
3123 session. See "Debugging Multiple Inferiors and Programs" in the
3124 manual for more information. This implied some user visible changes
3125 in the multi-inferior support. For example, "info inferiors" now
3126 lists inferiors that are not running yet or that have exited
3127 already. See also "New commands" and "New options" below.
3129 * New tracing features
3131 GDB's tracepoint facility now includes several new features:
3133 ** Trace state variables
3135 GDB tracepoints now include support for trace state variables, which
3136 are variables managed by the target agent during a tracing
3137 experiment. They are useful for tracepoints that trigger each
3138 other, so for instance one tracepoint can count hits in a variable,
3139 and then a second tracepoint has a condition that is true when the
3140 count reaches a particular value. Trace state variables share the
3141 $-syntax of GDB convenience variables, and can appear in both
3142 tracepoint actions and condition expressions. Use the "tvariable"
3143 command to create, and "info tvariables" to view; see "Trace State
3144 Variables" in the manual for more detail.
3148 GDB now includes an option for defining fast tracepoints, which
3149 targets may implement more efficiently, such as by installing a jump
3150 into the target agent rather than a trap instruction. The resulting
3151 speedup can be by two orders of magnitude or more, although the
3152 tradeoff is that some program locations on some target architectures
3153 might not allow fast tracepoint installation, for instance if the
3154 instruction to be replaced is shorter than the jump. To request a
3155 fast tracepoint, use the "ftrace" command, with syntax identical to
3156 the regular trace command.
3158 ** Disconnected tracing
3160 It is now possible to detach GDB from the target while it is running
3161 a trace experiment, then reconnect later to see how the experiment
3162 is going. In addition, a new variable disconnected-tracing lets you
3163 tell the target agent whether to continue running a trace if the
3164 connection is lost unexpectedly.
3168 GDB now has the ability to save the trace buffer into a file, and
3169 then use that file as a target, similarly to you can do with
3170 corefiles. You can select trace frames, print data that was
3171 collected in them, and use tstatus to display the state of the
3172 tracing run at the moment that it was saved. To create a trace
3173 file, use "tsave <filename>", and to use it, do "target tfile
3176 ** Circular trace buffer
3178 You can ask the target agent to handle the trace buffer as a
3179 circular buffer, discarding the oldest trace frames to make room for
3180 newer ones, by setting circular-trace-buffer to on. This feature may
3181 not be available for all target agents.
3186 The disassemble command, when invoked with two arguments, now requires
3187 the arguments to be comma-separated.
3190 The info variables command now displays variable definitions. Files
3191 which only declare a variable are not shown.
3194 The source command is now capable of sourcing Python scripts.
3195 This feature is dependent on the debugger being build with Python
3198 Related to this enhancement is also the introduction of a new command
3199 "set script-extension" (see below).
3201 * New commands (for set/show, see "New options" below)
3203 record save [<FILENAME>]
3204 Save a file (in core file format) containing the process record
3205 execution log for replay debugging at a later time.
3207 record restore <FILENAME>
3208 Restore the process record execution log that was saved at an
3209 earlier time, for replay debugging.
3211 add-inferior [-copies <N>] [-exec <FILENAME>]
3214 clone-inferior [-copies <N>] [ID]
3215 Make a new inferior ready to execute the same program another
3216 inferior has loaded.
3221 maint info program-spaces
3222 List the program spaces loaded into GDB.
3224 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3225 show remote interrupt-sequence
3226 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3227 as the sequence to the remote target in order to interrupt the execution.
3228 Ctrl-C is a default. Some system prefers BREAK which is high level of
3229 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3230 Magic SysRq g. It is BREAK signal and character 'g'.
3232 set remote interrupt-on-connect [on | off]
3233 show remote interrupt-on-connect
3234 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3235 remote target when gdb connects to it. This is needed when you debug
3238 set remotebreak [on | off]
3240 Deprecated. Use "set/show remote interrupt-sequence" instead.
3242 tvariable $NAME [ = EXP ]
3243 Create or modify a trace state variable.
3246 List trace state variables and their values.
3248 delete tvariable $NAME ...
3249 Delete one or more trace state variables.
3252 Evaluate the given expressions without collecting anything into the
3253 trace buffer. (Valid in tracepoint actions only.)
3255 ftrace FN / FILE:LINE / *ADDR
3256 Define a fast tracepoint at the given function, line, or address.
3258 * New expression syntax
3260 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3261 GDB now parses 0b101010 identically with 42.
3265 set follow-exec-mode new|same
3266 show follow-exec-mode
3267 Control whether GDB reuses the same inferior across an exec call or
3268 creates a new one. This is useful to be able to restart the old
3269 executable after the inferior having done an exec call.
3271 set default-collect EXPR, ...
3272 show default-collect
3273 Define a list of expressions to be collected at each tracepoint.
3274 This is a useful way to ensure essential items are not overlooked,
3275 such as registers or a critical global variable.
3277 set disconnected-tracing
3278 show disconnected-tracing
3279 If set to 1, the target is instructed to continue tracing if it
3280 loses its connection to GDB. If 0, the target is to stop tracing
3283 set circular-trace-buffer
3284 show circular-trace-buffer
3285 If set to on, the target is instructed to use a circular trace buffer
3286 and discard the oldest trace frames instead of stopping the trace due
3287 to a full trace buffer. If set to off, the trace stops when the buffer
3288 fills up. Some targets may not support this.
3290 set script-extension off|soft|strict
3291 show script-extension
3292 If set to "off", the debugger does not perform any script language
3293 recognition, and all sourced files are assumed to be GDB scripts.
3294 If set to "soft" (the default), files are sourced according to
3295 filename extension, falling back to GDB scripts if the first
3297 If set to "strict", files are sourced according to filename extension.
3299 set ada trust-PAD-over-XVS on|off
3300 show ada trust-PAD-over-XVS
3301 If off, activate a workaround against a bug in the debugging information
3302 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3303 the GCC sources for more information about the GNAT encoding and
3304 PAD types in particular). It is always safe to set this option to
3305 off, but this introduces a slight performance penalty. The default
3308 * Python API Improvements
3310 ** GDB provides the new class gdb.LazyString. This is useful in
3311 some pretty-printing cases. The new method gdb.Value.lazy_string
3312 provides a simple way to create objects of this type.
3314 ** The fields returned by gdb.Type.fields now have an
3315 `is_base_class' attribute.
3317 ** The new method gdb.Type.range returns the range of an array type.
3319 ** The new method gdb.parse_and_eval can be used to parse and
3320 evaluate an expression.
3322 * New remote packets
3325 Define a trace state variable.
3328 Get the current value of a trace state variable.
3331 Set desired tracing behavior upon disconnection.
3334 Set the trace buffer to be linear or circular.
3337 Get data about the tracepoints currently in use.
3341 Process record now works correctly with hardware watchpoints.
3343 Multiple bug fixes have been made to the mips-irix port, making it
3344 much more reliable. In particular:
3345 - Debugging threaded applications is now possible again. Previously,
3346 GDB would hang while starting the program, or while waiting for
3347 the program to stop at a breakpoint.
3348 - Attaching to a running process no longer hangs.
3349 - An error occurring while loading a core file has been fixed.
3350 - Changing the value of the PC register now works again. This fixes
3351 problems observed when using the "jump" command, or when calling
3352 a function from GDB, or even when assigning a new value to $pc.
3353 - With the "finish" and "return" commands, the return value for functions
3354 returning a small array is now correctly printed.
3355 - It is now possible to break on shared library code which gets executed
3356 during a shared library init phase (code executed while executing
3357 their .init section). Previously, the breakpoint would have no effect.
3358 - GDB is now able to backtrace through the signal handler for
3359 non-threaded programs.
3361 PIE (Position Independent Executable) programs debugging is now supported.
3362 This includes debugging execution of PIC (Position Independent Code) shared
3363 libraries although for that, it should be possible to run such libraries as an
3366 *** Changes in GDB 7.0
3368 * GDB now has an interface for JIT compilation. Applications that
3369 dynamically generate code can create symbol files in memory and register
3370 them with GDB. For users, the feature should work transparently, and
3371 for JIT developers, the interface is documented in the GDB manual in the
3372 "JIT Compilation Interface" chapter.
3374 * Tracepoints may now be conditional. The syntax is as for
3375 breakpoints; either an "if" clause appended to the "trace" command,
3376 or the "condition" command is available. GDB sends the condition to
3377 the target for evaluation using the same bytecode format as is used
3378 for tracepoint actions.
3380 * The disassemble command now supports: an optional /r modifier, print the
3381 raw instructions in hex as well as in symbolic form, and an optional /m
3382 modifier to print mixed source+assembly.
3384 * Process record and replay
3386 In a architecture environment that supports ``process record and
3387 replay'', ``process record and replay'' target can record a log of
3388 the process execution, and replay it with both forward and reverse
3391 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3392 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3393 set execution-direction {forward|reverse}, for targets that support
3396 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3397 feature is available with a native GDB running on kernel version
3400 * GDB now has support for multi-byte and wide character sets on the
3401 target. Strings whose character type is wchar_t, char16_t, or
3402 char32_t are now correctly printed. GDB supports wide- and unicode-
3403 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3404 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3405 `printf'. This feature requires iconv to work properly; if your
3406 system does not have a working iconv, GDB can use GNU libiconv. See
3407 the installation instructions for more information.
3409 * GDB now supports automatic retrieval of shared library files from
3410 remote targets. To use this feature, specify a system root that begins
3411 with the `remote:' prefix, either via the `set sysroot' command or via
3412 the `--with-sysroot' configure-time option.
3414 * "info sharedlibrary" now takes an optional regex of libraries to show,
3415 and it now reports if a shared library has no debugging information.
3417 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3418 now complete on file names.
3420 * When completing in expressions, gdb will attempt to limit
3421 completions to allowable structure or union fields, where appropriate.
3422 For instance, consider:
3424 # struct example { int f1; double f2; };
3425 # struct example variable;
3428 If the user types TAB at the end of this command line, the available
3429 completions will be "f1" and "f2".
3431 * Inlined functions are now supported. They show up in backtraces, and
3432 the "step", "next", and "finish" commands handle them automatically.
3434 * GDB now supports the token-splicing (##) and stringification (#)
3435 operators when expanding macros. It also supports variable-arity
3438 * GDB now supports inspecting extra signal information, exported by
3439 the new $_siginfo convenience variable. The feature is currently
3440 implemented on linux ARM, i386 and amd64.
3442 * GDB can now display the VFP floating point registers and NEON vector
3443 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3444 can provide these registers (requires Linux 2.6.30 or later). Remote
3445 and simulator targets may also provide them.
3447 * New remote packets
3450 Search memory for a sequence of bytes.
3453 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3454 operation over reliable transport links. Use of this packet is
3455 controlled by the `set remote noack-packet' command.
3458 Kill the process with the specified process ID. Use this in preference
3459 to `k' when multiprocess protocol extensions are supported.
3462 Obtains additional operating system information
3466 Read or write additional signal information.
3468 * Removed remote protocol undocumented extension
3470 An undocumented extension to the remote protocol's `S' stop reply
3471 packet that permited the stub to pass a process id was removed.
3472 Remote servers should use the `T' stop reply packet instead.
3474 * GDB now supports multiple function calling conventions according to the
3475 DWARF-2 DW_AT_calling_convention function attribute.
3477 * The SH target utilizes the aforementioned change to distinguish between gcc
3478 and Renesas calling convention. It also adds the new CLI commands
3479 `set/show sh calling-convention'.
3481 * GDB can now read compressed debug sections, as produced by GNU gold
3482 with the --compress-debug-sections=zlib flag.
3484 * 64-bit core files are now supported on AIX.
3486 * Thread switching is now supported on Tru64.
3488 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3489 which will be allocated using malloc later in program execution.
3491 * The qXfer:libraries:read remote procotol packet now allows passing a
3492 list of section offsets.
3494 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3495 conditions handling signals delivered during attach or thread creation
3496 have also been fixed.
3498 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3499 From the user's standpoint, all unqualified instances of True and False
3500 are treated as the standard definitions, regardless of context.
3502 * GDB now parses C++ symbol and type names more flexibly. For
3505 template<typename T> class C { };
3508 GDB will now correctly handle all of:
3510 ptype C<char const *>
3511 ptype C<char const*>
3512 ptype C<const char *>
3513 ptype C<const char*>
3515 * New features in the GDB remote stub, gdbserver
3517 - The "--wrapper" command-line argument tells gdbserver to use a
3518 wrapper program to launch programs for debugging.
3520 - On PowerPC and S/390 targets, it is now possible to use a single
3521 gdbserver executable to debug both 32-bit and 64-bit programs.
3522 (This requires gdbserver itself to be built as a 64-bit executable.)
3524 - gdbserver uses the new noack protocol mode for TCP connections to
3525 reduce communications latency, if also supported and enabled in GDB.
3527 - Support for the sparc64-linux-gnu target is now included in
3530 - The amd64-linux build of gdbserver now supports debugging both
3531 32-bit and 64-bit programs.
3533 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3534 now support hardware watchpoints, and will use them automatically
3539 GDB now has support for scripting using Python. Whether this is
3540 available is determined at configure time.
3542 New GDB commands can now be written in Python.
3544 * Ada tasking support
3546 Ada tasks can now be inspected in GDB. The following commands have
3550 Print the list of Ada tasks.
3552 Print detailed information about task number N.
3554 Print the task number of the current task.
3556 Switch the context of debugging to task number N.
3558 * Support for user-defined prefixed commands. The "define" command can
3559 add new commands to existing prefixes, e.g. "target".
3561 * Multi-inferior, multi-process debugging.
3563 GDB now has generalized support for multi-inferior debugging. See
3564 "Debugging Multiple Inferiors" in the manual for more information.
3565 Although availability still depends on target support, the command
3566 set is more uniform now. The GNU/Linux specific multi-forks support
3567 has been migrated to this new framework. This implied some user
3568 visible changes; see "New commands" and also "Removed commands"
3571 * Target descriptions can now describe the target OS ABI. See the
3572 "Target Description Format" section in the user manual for more
3575 * Target descriptions can now describe "compatible" architectures
3576 to indicate that the target can execute applications for a different
3577 architecture in addition to those for the main target architecture.
3578 See the "Target Description Format" section in the user manual for
3581 * Multi-architecture debugging.
3583 GDB now includes general supports for debugging applications on
3584 hybrid systems that use more than one single processor architecture
3585 at the same time. Each such hybrid architecture still requires
3586 specific support to be added. The only hybrid architecture supported
3587 in this version of GDB is the Cell Broadband Engine.
3589 * GDB now supports integrated debugging of Cell/B.E. applications that
3590 use both the PPU and SPU architectures. To enable support for hybrid
3591 Cell/B.E. debugging, you need to configure GDB to support both the
3592 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3593 --enable-targets configure option.
3595 * Non-stop mode debugging.
3597 For some targets, GDB now supports an optional mode of operation in
3598 which you can examine stopped threads while other threads continue
3599 to execute freely. This is referred to as non-stop mode, with the
3600 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3601 section in the user manual for more information.
3603 To be able to support remote non-stop debugging, a remote stub needs
3604 to implement the non-stop mode remote protocol extensions, as
3605 described in the "Remote Non-Stop" section of the user manual. The
3606 GDB remote stub, gdbserver, has been adjusted to support these
3607 extensions on linux targets.
3609 * New commands (for set/show, see "New options" below)
3611 catch syscall [NAME(S) | NUMBER(S)]
3612 Catch system calls. Arguments, which should be names of system
3613 calls or their numbers, mean catch only those syscalls. Without
3614 arguments, every syscall will be caught. When the inferior issues
3615 any of the specified syscalls, GDB will stop and announce the system
3616 call, both when it is called and when its call returns. This
3617 feature is currently available with a native GDB running on the
3618 Linux Kernel, under the following architectures: x86, x86_64,
3619 PowerPC and PowerPC64.
3621 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3623 Search memory for a sequence of bytes.
3625 maint set python print-stack
3626 maint show python print-stack
3627 Show a stack trace when an error is encountered in a Python script.
3630 Invoke CODE by passing it to the Python interpreter.
3635 These allow macros to be defined, undefined, and listed
3639 Show operating system information about processes.
3642 List the inferiors currently under GDB's control.
3645 Switch focus to inferior number NUM.
3648 Detach from inferior number NUM.
3651 Kill inferior number NUM.
3655 set spu stop-on-load
3656 show spu stop-on-load
3657 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3659 set spu auto-flush-cache
3660 show spu auto-flush-cache
3661 Control whether to automatically flush the software-managed cache
3662 during Cell/B.E. debugging.
3664 set sh calling-convention
3665 show sh calling-convention
3666 Control the calling convention used when calling SH target functions.
3669 show debug timestamp
3670 Control display of timestamps with GDB debugging output.
3672 set disassemble-next-line
3673 show disassemble-next-line
3674 Control display of disassembled source lines or instructions when
3677 set remote noack-packet
3678 show remote noack-packet
3679 Set/show the use of remote protocol QStartNoAckMode packet. See above
3680 under "New remote packets."
3682 set remote query-attached-packet
3683 show remote query-attached-packet
3684 Control use of remote protocol `qAttached' (query-attached) packet.
3686 set remote read-siginfo-object
3687 show remote read-siginfo-object
3688 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3691 set remote write-siginfo-object
3692 show remote write-siginfo-object
3693 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3696 set remote reverse-continue
3697 show remote reverse-continue
3698 Control use of remote protocol 'bc' (reverse-continue) packet.
3700 set remote reverse-step
3701 show remote reverse-step
3702 Control use of remote protocol 'bs' (reverse-step) packet.
3704 set displaced-stepping
3705 show displaced-stepping
3706 Control displaced stepping mode. Displaced stepping is a way to
3707 single-step over breakpoints without removing them from the debuggee.
3708 Also known as "out-of-line single-stepping".
3711 show debug displaced
3712 Control display of debugging info for displaced stepping.
3714 maint set internal-error
3715 maint show internal-error
3716 Control what GDB does when an internal error is detected.
3718 maint set internal-warning
3719 maint show internal-warning
3720 Control what GDB does when an internal warning is detected.
3725 Use a wrapper program to launch programs for debugging.
3727 set multiple-symbols (all|ask|cancel)
3728 show multiple-symbols
3729 The value of this variable can be changed to adjust the debugger behavior
3730 when an expression or a breakpoint location contains an ambiguous symbol
3731 name (an overloaded function name, for instance).
3733 set breakpoint always-inserted
3734 show breakpoint always-inserted
3735 Keep breakpoints always inserted in the target, as opposed to inserting
3736 them when resuming the target, and removing them when the target stops.
3737 This option can improve debugger performance on slow remote targets.
3739 set arm fallback-mode (arm|thumb|auto)
3740 show arm fallback-mode
3741 set arm force-mode (arm|thumb|auto)
3743 These commands control how ARM GDB determines whether instructions
3744 are ARM or Thumb. The default for both settings is auto, which uses
3745 the current CPSR value for instructions without symbols; previous
3746 versions of GDB behaved as if "set arm fallback-mode arm".
3748 set disable-randomization
3749 show disable-randomization
3750 Standalone programs run with the virtual address space randomization enabled
3751 by default on some platforms. This option keeps the addresses stable across
3752 multiple debugging sessions.
3756 Control whether other threads are stopped or not when some thread hits
3761 Requests that asynchronous execution is enabled in the target, if available.
3762 In this case, it's possible to resume target in the background, and interact
3763 with GDB while the target is running. "show target-async" displays the
3764 current state of asynchronous execution of the target.
3766 set target-wide-charset
3767 show target-wide-charset
3768 The target-wide-charset is the name of the character set that GDB
3769 uses when printing characters whose type is wchar_t.
3771 set tcp auto-retry (on|off)
3773 set tcp connect-timeout
3774 show tcp connect-timeout
3775 These commands allow GDB to retry failed TCP connections to a remote stub
3776 with a specified timeout period; this is useful if the stub is launched
3777 in parallel with GDB but may not be ready to accept connections immediately.
3779 set libthread-db-search-path
3780 show libthread-db-search-path
3781 Control list of directories which GDB will search for appropriate
3784 set schedule-multiple (on|off)
3785 show schedule-multiple
3786 Allow GDB to resume all threads of all processes or only threads of
3787 the current process.
3791 Use more aggressive caching for accesses to the stack. This improves
3792 performance of remote debugging (particularly backtraces) without
3793 affecting correctness.
3795 set interactive-mode (on|off|auto)
3796 show interactive-mode
3797 Control whether GDB runs in interactive mode (on) or not (off).
3798 When in interactive mode, GDB waits for the user to answer all
3799 queries. Otherwise, GDB does not wait and assumes the default
3800 answer. When set to auto (the default), GDB determines which
3801 mode to use based on the stdin settings.
3806 For program forks, this is replaced by the new more generic `info
3807 inferiors' command. To list checkpoints, you can still use the
3808 `info checkpoints' command, which was an alias for the `info forks'
3812 Replaced by the new `inferior' command. To switch between
3813 checkpoints, you can still use the `restart' command, which was an
3814 alias for the `fork' command.
3817 This is removed, since some targets don't have a notion of
3818 processes. To switch between processes, you can still use the
3819 `inferior' command using GDB's own inferior number.
3822 For program forks, this is replaced by the new more generic `kill
3823 inferior' command. To delete a checkpoint, you can still use the
3824 `delete checkpoint' command, which was an alias for the `delete
3828 For program forks, this is replaced by the new more generic `detach
3829 inferior' command. To detach a checkpoint, you can still use the
3830 `detach checkpoint' command, which was an alias for the `detach
3833 * New native configurations
3835 x86/x86_64 Darwin i[34567]86-*-darwin*
3837 x86_64 MinGW x86_64-*-mingw*
3841 Lattice Mico32 lm32-*
3842 x86 DICOS i[34567]86-*-dicos*
3843 x86_64 DICOS x86_64-*-dicos*
3846 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3847 (mingw32ce) debugging.
3853 These commands were actually not implemented on any target.
3855 *** Changes in GDB 6.8
3857 * New native configurations
3859 NetBSD/hppa hppa*-*netbsd*
3860 Xtensa GNU/Linux xtensa*-*-linux*
3864 NetBSD/hppa hppa*-*-netbsd*
3865 Xtensa GNU/Lunux xtensa*-*-linux*
3867 * Change in command line behavior -- corefiles vs. process ids.
3869 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3870 attaching to process NUMBER fails, GDB no longer attempts to open a
3871 core file named NUMBER. Attaching to a program using the -c option
3872 is no longer supported. Instead, use the '-p' or '--pid' options.
3874 * GDB can now be built as a native debugger for debugging Windows x86
3875 (mingw32) Portable Executable (PE) programs.
3877 * Pending breakpoints no longer change their number when their address
3880 * GDB now supports breakpoints with multiple locations,
3881 including breakpoints on C++ constructors, inside C++ templates,
3882 and in inlined functions.
3884 * GDB's ability to debug optimized code has been improved. GDB more
3885 accurately identifies function bodies and lexical blocks that occupy
3886 more than one contiguous range of addresses.
3888 * Target descriptions can now describe registers for PowerPC.
3890 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3891 registers on PowerPC targets.
3893 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3894 targets even when the libthread_db library is not available.
3896 * The GDB remote stub, gdbserver, now supports the new file transfer
3897 commands (remote put, remote get, and remote delete).
3899 * The GDB remote stub, gdbserver, now supports run and attach in
3900 extended-remote mode.
3902 * hppa*64*-*-hpux11* target broken
3903 The debugger is unable to start a program and fails with the following
3904 error: "Error trying to get information about dynamic linker".
3905 The gdb-6.7 release is also affected.
3907 * GDB now supports the --enable-targets= configure option to allow
3908 building a single GDB executable that supports multiple remote
3909 target architectures.
3911 * GDB now supports debugging C and C++ programs which use the
3912 Decimal Floating Point extension. In addition, the PowerPC target
3913 now has a set of pseudo-registers to inspect decimal float values
3914 stored in two consecutive float registers.
3916 * The -break-insert MI command can optionally create pending
3919 * Improved support for debugging Ada
3920 Many improvements to the Ada language support have been made. These
3922 - Better support for Ada2005 interface types
3923 - Improved handling of arrays and slices in general
3924 - Better support for Taft-amendment types
3925 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3927 - Improved command completion in Ada
3930 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3935 set print frame-arguments (all|scalars|none)
3936 show print frame-arguments
3937 The value of this variable can be changed to control which argument
3938 values should be printed by the debugger when displaying a frame.
3943 Transfer files to and from a remote target, and delete remote files.
3950 Transfer files to and from a remote target, and delete remote files.
3952 * New remote packets
3959 Open, close, read, write, and delete files on the remote system.
3962 Attach to an existing process on the remote system, in extended-remote
3966 Run a new process on the remote system, in extended-remote mode.
3968 *** Changes in GDB 6.7
3970 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3971 bfd, libiberty and opcodes, as revealed by static analysis donated by
3972 Coverity, Inc. (http://scan.coverity.com).
3974 * When looking up multiply-defined global symbols, GDB will now prefer the
3975 symbol definition in the current shared library if it was built using the
3976 -Bsymbolic linker option.
3978 * When the Text User Interface (TUI) is not configured, GDB will now
3979 recognize the -tui command-line option and print a message that the TUI
3982 * The GDB remote stub, gdbserver, now has lower overhead for high
3983 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3985 * GDB for MIPS targets now autodetects whether a remote target provides
3986 32-bit or 64-bit register values.
3988 * Support for C++ member pointers has been improved.
3990 * GDB now understands XML target descriptions, which specify the
3991 target's overall architecture. GDB can read a description from
3992 a local file or over the remote serial protocol.
3994 * Vectors of single-byte data use a new integer type which is not
3995 automatically displayed as character or string data.
3997 * The /s format now works with the print command. It displays
3998 arrays of single-byte integers and pointers to single-byte integers
4001 * Target descriptions can now describe target-specific registers,
4002 for architectures which have implemented the support (currently
4003 only ARM, M68K, and MIPS).
4005 * GDB and the GDB remote stub, gdbserver, now support the XScale
4008 * The GDB remote stub, gdbserver, has been updated to support
4009 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4010 has been rewritten to use the standard GDB remote protocol.
4012 * GDB can now step into C++ functions which are called through thunks.
4014 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4016 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4017 layout. It also supports a TextSeg= and DataSeg= response when only
4018 segment base addresses (rather than offsets) are available.
4020 * The /i format now outputs any trailing branch delay slot instructions
4021 immediately following the last instruction within the count specified.
4023 * The GDB remote protocol "T" stop reply packet now supports a
4024 "library" response. Combined with the new "qXfer:libraries:read"
4025 packet, this response allows GDB to debug shared libraries on targets
4026 where the operating system manages the list of loaded libraries (e.g.
4027 Windows and SymbianOS).
4029 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4030 (DLLs) on Windows and Windows CE targets.
4032 * GDB now supports a faster verification that a .debug file matches its binary
4033 according to its build-id signature, if the signature is present.
4039 Enable or disable hardware flow control (RTS/CTS) on the serial port
4040 when debugging using remote targets.
4042 set mem inaccessible-by-default
4043 show mem inaccessible-by-default
4044 If the target supplies a memory map, for instance via the remote
4045 protocol's "qXfer:memory-map:read" packet, setting this variable
4046 prevents GDB from accessing memory outside the memory map. This
4047 is useful for targets with memory mapped registers or which react
4048 badly to accesses of unmapped address space.
4050 set breakpoint auto-hw
4051 show breakpoint auto-hw
4052 If the target supplies a memory map, for instance via the remote
4053 protocol's "qXfer:memory-map:read" packet, setting this variable
4054 lets GDB use hardware breakpoints automatically for memory regions
4055 where it can not use software breakpoints. This covers both the
4056 "break" command and internal breakpoints used for other commands
4057 including "next" and "finish".
4060 catch exception unhandled
4061 Stop the program execution when Ada exceptions are raised.
4064 Stop the program execution when an Ada assertion failed.
4068 Set an alternate system root for target files. This is a more
4069 general version of "set solib-absolute-prefix", which is now
4070 an alias to "set sysroot".
4073 Provide extended SPU facility status information. This set of
4074 commands is available only when debugging the Cell/B.E. SPU
4077 * New native configurations
4079 OpenBSD/sh sh*-*openbsd*
4082 unset tdesc filename
4084 Use the specified local file as an XML target description, and do
4085 not query the target for its built-in description.
4089 OpenBSD/sh sh*-*-openbsd*
4090 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4091 Toshiba Media Processor mep-elf
4093 * New remote packets
4096 Ignore the specified signals; pass them directly to the debugged program
4097 without stopping other threads or reporting them to GDB.
4099 qXfer:features:read:
4100 Read an XML target description from the target, which describes its
4105 Read or write contents of an spufs file on the target system. These
4106 packets are available only on the Cell/B.E. SPU architecture.
4108 qXfer:libraries:read:
4109 Report the loaded shared libraries. Combined with new "T" packet
4110 response, this packet allows GDB to debug shared libraries on
4111 targets where the operating system manages the list of loaded
4112 libraries (e.g. Windows and SymbianOS).
4116 Support for these obsolete configurations has been removed.
4124 i[34567]86-*-lynxos*
4125 i[34567]86-*-netware*
4126 i[34567]86-*-sco3.2v5*
4127 i[34567]86-*-sco3.2v4*
4129 i[34567]86-*-sysv4.2*
4132 i[34567]86-*-unixware2*
4133 i[34567]86-*-unixware*
4142 * Other removed features
4149 Various m68k-only ROM monitors.
4156 Various Renesas ROM monitors and debugging interfaces for SH and
4161 Support for a Macraigor serial interface to on-chip debugging.
4162 GDB does not directly support the newer parallel or USB
4167 A debug information format. The predecessor to DWARF 2 and
4168 DWARF 3, which are still supported.
4170 Support for the HP aCC compiler on HP-UX/PA-RISC
4172 SOM-encapsulated symbolic debugging information, automatic
4173 invocation of pxdb, and the aCC custom C++ ABI. This does not
4174 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4175 with aCC can still be debugged on an assembly level.
4177 MIPS ".pdr" sections
4179 A MIPS-specific format used to describe stack frame layout
4180 in debugging information.
4184 GDB could work with an older version of Guile to debug
4185 the interpreter and Scheme programs running in it.
4187 set mips stack-arg-size
4188 set mips saved-gpreg-size
4190 Use "set mips abi" to control parameter passing for MIPS.
4192 *** Changes in GDB 6.6
4197 Cell Broadband Engine SPU spu-elf
4199 * GDB can now be configured as a cross-debugger targeting native Windows
4200 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4201 running on a Windows system over TCP/IP to debug Windows programs.
4203 * The GDB remote stub, gdbserver, has been updated to support Windows and
4204 Cygwin debugging. Both single-threaded and multi-threaded programs are
4207 * The "set trust-readonly-sections" command works again. This command was
4208 broken in GDB 6.3, 6.4, and 6.5.
4210 * The "load" command now supports writing to flash memory, if the remote
4211 stub provides the required support.
4213 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4214 longer requires symbolic debug information (e.g. DWARF-2).
4219 unset substitute-path
4220 show substitute-path
4221 Manage a list of substitution rules that GDB uses to rewrite the name
4222 of the directories where the sources are located. This can be useful
4223 for instance when the sources were moved to a different location
4224 between compilation and debugging.
4228 Print each CLI command as it is executed. Each command is prefixed with
4229 a number of `+' symbols representing the nesting depth.
4230 The source command now has a `-v' option to enable the same feature.
4234 The ARM Demon monitor support (RDP protocol, "target rdp").
4236 Kernel Object Display, an embedded debugging feature which only worked with
4237 an obsolete version of Cisco IOS.
4239 The 'set download-write-size' and 'show download-write-size' commands.
4241 * New remote packets
4244 Tell a stub about GDB client features, and request remote target features.
4245 The first feature implemented is PacketSize, which allows the target to
4246 specify the size of packets it can handle - to minimize the number of
4247 packets required and improve performance when connected to a remote
4251 Fetch an OS auxilliary vector from the remote stub. This packet is a
4252 more efficient replacement for qPart:auxv:read.
4254 qXfer:memory-map:read:
4255 Fetch a memory map from the remote stub, including information about
4256 RAM, ROM, and flash memory devices.
4261 Erase and program a flash memory device.
4263 * Removed remote packets
4266 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4267 used it, and only gdbserver implemented it.
4269 *** Changes in GDB 6.5
4273 Renesas M32C/M16C m32c-elf
4275 Morpho Technologies ms1 ms1-elf
4279 init-if-undefined Initialize a convenience variable, but
4280 only if it doesn't already have a value.
4282 The following commands are presently only implemented for native GNU/Linux:
4284 checkpoint Save a snapshot of the program state.
4286 restart <n> Return the program state to a
4287 previously saved state.
4289 info checkpoints List currently saved checkpoints.
4291 delete-checkpoint <n> Delete a previously saved checkpoint.
4293 set|show detach-on-fork Tell gdb whether to detach from a newly
4294 forked process, or to keep debugging it.
4296 info forks List forks of the user program that
4297 are available to be debugged.
4299 fork <n> Switch to debugging one of several
4300 forks of the user program that are
4301 available to be debugged.
4303 delete-fork <n> Delete a fork from the list of forks
4304 that are available to be debugged (and
4305 kill the forked process).
4307 detach-fork <n> Delete a fork from the list of forks
4308 that are available to be debugged (and
4309 allow the process to continue).
4313 Morpho Technologies ms2 ms1-elf
4315 * Improved Windows host support
4317 GDB now builds as a cross debugger hosted on i686-mingw32, including
4318 native console support, and remote communications using either
4319 network sockets or serial ports.
4321 * Improved Modula-2 language support
4323 GDB can now print most types in the Modula-2 syntax. This includes:
4324 basic types, set types, record types, enumerated types, range types,
4325 pointer types and ARRAY types. Procedure var parameters are correctly
4326 printed and hexadecimal addresses and character constants are also
4327 written in the Modula-2 syntax. Best results can be obtained by using
4328 GNU Modula-2 together with the -gdwarf-2 command line option.
4332 The ARM rdi-share module.
4334 The Netware NLM debug server.
4336 *** Changes in GDB 6.4
4338 * New native configurations
4340 OpenBSD/arm arm*-*-openbsd*
4341 OpenBSD/mips64 mips64-*-openbsd*
4345 Morpho Technologies ms1 ms1-elf
4347 * New command line options
4349 --batch-silent As for --batch, but totally silent.
4350 --return-child-result The debugger will exist with the same value
4351 the child (debugged) program exited with.
4352 --eval-command COMMAND, -ex COMMAND
4353 Execute a single GDB CLI command. This may be
4354 specified multiple times and in conjunction
4355 with the --command (-x) option.
4357 * Deprecated commands removed
4359 The following commands, that were deprecated in 2000, have been
4363 set|show arm disassembly-flavor set|show arm disassembler
4364 othernames set arm disassembler
4365 set|show remotedebug set|show debug remote
4366 set|show archdebug set|show debug arch
4367 set|show eventdebug set|show debug event
4370 * New BSD user-level threads support
4372 It is now possible to debug programs using the user-level threads
4373 library on OpenBSD and FreeBSD. Currently supported (target)
4376 FreeBSD/amd64 x86_64-*-freebsd*
4377 FreeBSD/i386 i386-*-freebsd*
4378 OpenBSD/i386 i386-*-openbsd*
4380 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4381 are not yet supported.
4383 * New support for Matsushita MN10300 w/sim added
4384 (Work in progress). mn10300-elf.
4386 * REMOVED configurations and files
4388 VxWorks and the XDR protocol *-*-vxworks
4389 Motorola MCORE mcore-*-*
4390 National Semiconductor NS32000 ns32k-*-*
4392 * New "set print array-indexes" command
4394 After turning this setting "on", GDB prints the index of each element
4395 when displaying arrays. The default is "off" to preserve the previous
4398 * VAX floating point support
4400 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4402 * User-defined command support
4404 In addition to using $arg0..$arg9 for argument passing, it is now possible
4405 to use $argc to determine now many arguments have been passed. See the
4406 section on user-defined commands in the user manual for more information.
4408 *** Changes in GDB 6.3:
4410 * New command line option
4412 GDB now accepts -l followed by a number to set the timeout for remote
4415 * GDB works with GCC -feliminate-dwarf2-dups
4417 GDB now supports a more compact representation of DWARF-2 debug
4418 information using DW_FORM_ref_addr references. These are produced
4419 by GCC with the option -feliminate-dwarf2-dups and also by some
4420 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4421 to use -feliminate-dwarf2-dups.
4423 * Internationalization
4425 When supported by the host system, GDB will be built with
4426 internationalization (libintl). The task of marking up the sources is
4427 continued, we're looking forward to our first translation.
4431 Initial support for debugging programs compiled with the GNAT
4432 implementation of the Ada programming language has been integrated
4433 into GDB. In this release, support is limited to expression evaluation.
4435 * New native configurations
4437 GNU/Linux/m32r m32r-*-linux-gnu
4441 GDB's remote protocol now includes support for the 'p' packet. This
4442 packet is used to fetch individual registers from a remote inferior.
4444 * END-OF-LIFE registers[] compatibility module
4446 GDB's internal register infrastructure has been completely rewritten.
4447 The new infrastructure making possible the implementation of key new
4448 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4451 GDB 6.3 will be the last release to include the the registers[]
4452 compatibility module that allowed out-of-date configurations to
4453 continue to work. This change directly impacts the following
4463 powerpc bdm protocol
4465 Unless there is activity to revive these configurations, they will be
4466 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4468 * OBSOLETE configurations and files
4470 Configurations that have been declared obsolete in this release have
4471 been commented out. Unless there is activity to revive these
4472 configurations, the next release of GDB will have their sources
4473 permanently REMOVED.
4482 *** Changes in GDB 6.2.1:
4484 * MIPS `break main; run' gave an heuristic-fence-post warning
4486 When attempting to run even a simple program, a warning about
4487 heuristic-fence-post being hit would be reported. This problem has
4490 * MIPS IRIX 'long double' crashed GDB
4492 When examining a long double variable, GDB would get a segmentation
4493 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4494 IRIX long double values).
4498 A bug in the VAX stack code was causing problems with the "next"
4499 command. This problem has been fixed.
4501 *** Changes in GDB 6.2:
4503 * Fix for ``many threads''
4505 On GNU/Linux systems that use the NPTL threads library, a program
4506 rapidly creating and deleting threads would confuse GDB leading to the
4509 ptrace: No such process.
4510 thread_db_get_info: cannot get thread info: generic error
4512 This problem has been fixed.
4514 * "-async" and "-noasync" options removed.
4516 Support for the broken "-noasync" option has been removed (it caused
4519 * New ``start'' command.
4521 This command runs the program until the begining of the main procedure.
4523 * New BSD Kernel Data Access Library (libkvm) interface
4525 Using ``target kvm'' it is now possible to debug kernel core dumps and
4526 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4527 platforms. Currently supported (native-only) configurations are:
4529 FreeBSD/amd64 x86_64-*-freebsd*
4530 FreeBSD/i386 i?86-*-freebsd*
4531 NetBSD/i386 i?86-*-netbsd*
4532 NetBSD/m68k m68*-*-netbsd*
4533 NetBSD/sparc sparc-*-netbsd*
4534 OpenBSD/amd64 x86_64-*-openbsd*
4535 OpenBSD/i386 i?86-*-openbsd*
4536 OpenBSD/m68k m68*-openbsd*
4537 OpenBSD/sparc sparc-*-openbsd*
4539 * Signal trampoline code overhauled
4541 Many generic problems with GDB's signal handling code have been fixed.
4542 These include: backtraces through non-contiguous stacks; recognition
4543 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4544 call; backtrace through a signal trampoline; step into and out of
4545 signal handlers; and single-stepping in the signal trampoline.
4547 Please note that kernel bugs are a limiting factor here. These
4548 features have been shown to work on an s390 GNU/Linux system that
4549 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4551 * Cygwin support for DWARF 2 added.
4553 * New native configurations
4555 GNU/Linux/hppa hppa*-*-linux*
4556 OpenBSD/hppa hppa*-*-openbsd*
4557 OpenBSD/m68k m68*-*-openbsd*
4558 OpenBSD/m88k m88*-*-openbsd*
4559 OpenBSD/powerpc powerpc-*-openbsd*
4560 NetBSD/vax vax-*-netbsd*
4561 OpenBSD/vax vax-*-openbsd*
4563 * END-OF-LIFE frame compatibility module
4565 GDB's internal frame infrastructure has been completely rewritten.
4566 The new infrastructure making it possible to support key new features
4567 including DWARF 2 Call Frame Information. To aid in the task of
4568 migrating old configurations to this new infrastructure, a
4569 compatibility module, that allowed old configurations to continue to
4570 work, was also included.
4572 GDB 6.2 will be the last release to include this frame compatibility
4573 module. This change directly impacts the following configurations:
4583 Unless there is activity to revive these configurations, they will be
4584 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4586 * REMOVED configurations and files
4588 Sun 3, running SunOS 3 m68*-*-sunos3*
4589 Sun 3, running SunOS 4 m68*-*-sunos4*
4590 Sun 2, running SunOS 3 m68000-*-sunos3*
4591 Sun 2, running SunOS 4 m68000-*-sunos4*
4592 Motorola 680x0 running LynxOS m68*-*-lynxos*
4593 AT&T 3b1/Unix pc m68*-att-*
4594 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4595 decstation mips-dec-* mips-little-*
4596 riscos mips-*-riscos* mips-*-sysv*
4597 sonymips mips-sony-*
4598 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4600 *** Changes in GDB 6.1.1:
4602 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4604 The TUI (Text-mode User Interface) is now built as part of a default
4605 GDB configuration. It is enabled by either selecting the TUI with the
4606 command line option "-i=tui" or by running the separate "gdbtui"
4607 program. For more information on the TUI, see the manual "Debugging
4610 * Pending breakpoint support (also included in GDB 6.1)
4612 Support has been added to allow you to specify breakpoints in shared
4613 libraries that have not yet been loaded. If a breakpoint location
4614 cannot be found, and the "breakpoint pending" option is set to auto,
4615 GDB queries you if you wish to make the breakpoint pending on a future
4616 shared-library load. If and when GDB resolves the breakpoint symbol,
4617 the pending breakpoint is removed as one or more regular breakpoints
4620 Pending breakpoints are very useful for GCJ Java debugging.
4622 * Fixed ISO-C build problems
4624 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4625 non ISO-C code that stopped them being built using a more strict ISO-C
4626 compiler (e.g., IBM's C compiler).
4628 * Fixed build problem on IRIX 5
4630 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4631 wasn't able to compile compile on an IRIX 5 system.
4633 * Added execute permission to gdb/gdbserver/configure
4635 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4636 permission. This bug would cause configure to fail on a number of
4637 systems (Solaris, IRIX). Ref: server/519.
4639 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4641 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4642 has been updated to use constant array sizes.
4644 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4646 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4647 its generated DWARF Call Frame Info. This encoding was causing GDB to
4648 panic, that panic has been fixed. Ref: gdb/1628.
4650 * Fixed a problem when examining parameters in shared library code.
4652 When examining parameters in optimized shared library code generated
4653 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4654 not available''. GDB now correctly displays the variable's value.
4656 *** Changes in GDB 6.1:
4658 * Removed --with-mmalloc
4660 Support for the mmalloc memory manager has been removed, as it
4661 conflicted with the internal gdb byte cache.
4663 * Changes in AMD64 configurations
4665 The AMD64 target now includes the %cs and %ss registers. As a result
4666 the AMD64 remote protocol has changed; this affects the floating-point
4667 and SSE registers. If you rely on those registers for your debugging,
4668 you should upgrade gdbserver on the remote side.
4670 * Revised SPARC target
4672 The SPARC target has been completely revised, incorporating the
4673 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4674 support for LynxOS and SunOS 4 has been dropped. Calling functions
4675 from within GDB on operating systems with a non-executable stack
4676 (Solaris, OpenBSD) now works.
4680 GDB has a new C++ demangler which does a better job on the mangled
4681 names generated by current versions of g++. It also runs faster, so
4682 with this and other changes gdb should now start faster on large C++
4685 * DWARF 2 Location Expressions
4687 GDB support for location expressions has been extended to support function
4688 arguments and frame bases. Older versions of GDB could crash when they
4691 * C++ nested types and namespaces
4693 GDB's support for nested types and namespaces in C++ has been
4694 improved, especially if you use the DWARF 2 debugging format. (This
4695 is the default for recent versions of GCC on most platforms.)
4696 Specifically, if you have a class "Inner" defined within a class or
4697 namespace "Outer", then GDB realizes that the class's name is
4698 "Outer::Inner", not simply "Inner". This should greatly reduce the
4699 frequency of complaints about not finding RTTI symbols. In addition,
4700 if you are stopped at inside of a function defined within a namespace,
4701 GDB modifies its name lookup accordingly.
4703 * New native configurations
4705 NetBSD/amd64 x86_64-*-netbsd*
4706 OpenBSD/amd64 x86_64-*-openbsd*
4707 OpenBSD/alpha alpha*-*-openbsd*
4708 OpenBSD/sparc sparc-*-openbsd*
4709 OpenBSD/sparc64 sparc64-*-openbsd*
4711 * New debugging protocols
4713 M32R with SDI protocol m32r-*-elf*
4715 * "set prompt-escape-char" command deleted.
4717 The command "set prompt-escape-char" has been deleted. This command,
4718 and its very obscure effet on GDB's prompt, was never documented,
4719 tested, nor mentioned in the NEWS file.
4721 * OBSOLETE configurations and files
4723 Configurations that have been declared obsolete in this release have
4724 been commented out. Unless there is activity to revive these
4725 configurations, the next release of GDB will have their sources
4726 permanently REMOVED.
4728 Sun 3, running SunOS 3 m68*-*-sunos3*
4729 Sun 3, running SunOS 4 m68*-*-sunos4*
4730 Sun 2, running SunOS 3 m68000-*-sunos3*
4731 Sun 2, running SunOS 4 m68000-*-sunos4*
4732 Motorola 680x0 running LynxOS m68*-*-lynxos*
4733 AT&T 3b1/Unix pc m68*-att-*
4734 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4735 decstation mips-dec-* mips-little-*
4736 riscos mips-*-riscos* mips-*-sysv*
4737 sonymips mips-sony-*
4738 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4740 * REMOVED configurations and files
4742 SGI Irix-4.x mips-sgi-irix4 or iris4
4743 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4744 Z8000 simulator z8k-zilog-none or z8ksim
4745 Matsushita MN10200 w/simulator mn10200-*-*
4746 H8/500 simulator h8500-hitachi-hms or h8500hms
4747 HP/PA running BSD hppa*-*-bsd*
4748 HP/PA running OSF/1 hppa*-*-osf*
4749 HP/PA Pro target hppa*-*-pro*
4750 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4751 386BSD i[3456]86-*-bsd*
4752 Sequent family i[3456]86-sequent-sysv4*
4753 i[3456]86-sequent-sysv*
4754 i[3456]86-sequent-bsd*
4755 SPARC running LynxOS sparc-*-lynxos*
4756 SPARC running SunOS 4 sparc-*-sunos4*
4757 Tsqware Sparclet sparclet-*-*
4758 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4760 *** Changes in GDB 6.0:
4764 Support for debugging the Objective-C programming language has been
4765 integrated into GDB.
4767 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4769 DWARF 2's Call Frame Information makes available compiler generated
4770 information that more exactly describes the program's run-time stack.
4771 By using this information, GDB is able to provide more robust stack
4774 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4775 have been updated to use a new backtrace mechanism which includes
4776 DWARF 2 CFI support.
4780 GDB's remote protocol has been extended to include support for hosted
4781 file I/O (where the remote target uses GDB's file system). See GDB's
4782 remote protocol documentation for details.
4784 * All targets using the new architecture framework.
4786 All of GDB's targets have been updated to use the new internal
4787 architecture framework. The way is now open for future GDB releases
4788 to include cross-architecture native debugging support (i386 on amd64,
4791 * GNU/Linux's Thread Local Storage (TLS)
4793 GDB now includes support for for the GNU/Linux implementation of
4794 per-thread variables.
4796 * GNU/Linux's Native POSIX Thread Library (NPTL)
4798 GDB's thread code has been updated to work with either the new
4799 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4801 * Separate debug info.
4803 GDB, in conjunction with BINUTILS, now supports a mechanism for
4804 automatically loading debug information from a separate file. Instead
4805 of shipping full debug and non-debug versions of system libraries,
4806 system integrators can now instead ship just the stripped libraries
4807 and optional debug files.
4809 * DWARF 2 Location Expressions
4811 DWARF 2 Location Expressions allow the compiler to more completely
4812 describe the location of variables (even in optimized code) to the
4815 GDB now includes preliminary support for location expressions (support
4816 for DW_OP_piece is still missing).
4820 A number of long standing bugs that caused GDB to die while starting a
4821 Java application have been fixed. GDB's Java support is now
4822 considered "useable".
4824 * GNU/Linux support for fork, vfork, and exec.
4826 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4827 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4830 * GDB supports logging output to a file
4832 There are two new commands, "set logging" and "show logging", which can be
4833 used to capture GDB's output to a file.
4835 * The meaning of "detach" has changed for gdbserver
4837 The "detach" command will now resume the application, as documented. To
4838 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4841 * d10v, m68hc11 `regs' command deprecated
4843 The `info registers' command has been updated so that it displays the
4844 registers using a format identical to the old `regs' command.
4848 A new command, "maint set profile on/off", has been added. This command can
4849 be used to enable or disable profiling while running GDB, to profile a
4850 session or a set of commands. In addition there is a new configure switch,
4851 "--enable-profiling", which will cause GDB to be compiled with profiling
4852 data, for more informative profiling results.
4854 * Default MI syntax changed to "mi2".
4856 The default MI (machine interface) syntax, enabled by the command line
4857 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4858 "mi1", can be enabled by specifying the option "-i=mi1".
4860 Support for the original "mi0" syntax (included in GDB 5.0) has been
4863 Fix for gdb/192: removed extraneous space when displaying frame level.
4864 Fix for gdb/672: update changelist is now output in mi list format.
4865 Fix for gdb/702: a -var-assign that updates the value now shows up
4866 in a subsequent -var-update.
4868 * New native configurations.
4870 FreeBSD/amd64 x86_64-*-freebsd*
4872 * Multi-arched targets.
4874 HP/PA HPUX11 hppa*-*-hpux*
4875 Renesas M32R/D w/simulator m32r-*-elf*
4877 * OBSOLETE configurations and files
4879 Configurations that have been declared obsolete in this release have
4880 been commented out. Unless there is activity to revive these
4881 configurations, the next release of GDB will have their sources
4882 permanently REMOVED.
4884 Z8000 simulator z8k-zilog-none or z8ksim
4885 Matsushita MN10200 w/simulator mn10200-*-*
4886 H8/500 simulator h8500-hitachi-hms or h8500hms
4887 HP/PA running BSD hppa*-*-bsd*
4888 HP/PA running OSF/1 hppa*-*-osf*
4889 HP/PA Pro target hppa*-*-pro*
4890 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4891 Sequent family i[3456]86-sequent-sysv4*
4892 i[3456]86-sequent-sysv*
4893 i[3456]86-sequent-bsd*
4894 Tsqware Sparclet sparclet-*-*
4895 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4897 * REMOVED configurations and files
4900 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4901 IBM AIX PS/2 i[3456]86-*-aix
4902 i386 running Mach 3.0 i[3456]86-*-mach3*
4903 i386 running Mach i[3456]86-*-mach*
4904 i386 running OSF/1 i[3456]86-*osf1mk*
4905 HP/Apollo 68k Family m68*-apollo*-sysv*,
4907 m68*-hp-bsd*, m68*-hp-hpux*
4908 Argonaut Risc Chip (ARC) arc-*-*
4909 Mitsubishi D30V d30v-*-*
4910 Fujitsu FR30 fr30-*-elf*
4911 OS/9000 i[34]86-*-os9k
4912 I960 with MON960 i960-*-coff
4914 * MIPS $fp behavior changed
4916 The convenience variable $fp, for the MIPS, now consistently returns
4917 the address of the current frame's base. Previously, depending on the
4918 context, $fp could refer to either $sp or the current frame's base
4919 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4920 The GNU Source-Level Debugger''.
4922 *** Changes in GDB 5.3:
4924 * GNU/Linux shared library multi-threaded performance improved.
4926 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4927 `/proc', in preference to `ptrace' for memory reads. This may result
4928 in an improvement in the start-up time of multi-threaded, shared
4929 library applications when run under GDB. One GDB user writes: ``loads
4930 shared libs like mad''.
4932 * ``gdbserver'' now supports multi-threaded applications on some targets
4934 Support for debugging multi-threaded applications which use
4935 the GNU/Linux LinuxThreads package has been added for
4936 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4937 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4939 * GDB now supports C/C++ preprocessor macros.
4941 GDB now expands preprocessor macro invocations in C/C++ expressions,
4942 and provides various commands for showing macro definitions and how
4945 The new command `macro expand EXPRESSION' expands any macro
4946 invocations in expression, and shows the result.
4948 The new command `show macro MACRO-NAME' shows the definition of the
4949 macro named MACRO-NAME, and where it was defined.
4951 Most compilers don't include information about macros in the debugging
4952 information by default. In GCC 3.1, for example, you need to compile
4953 your program with the options `-gdwarf-2 -g3'. If the macro
4954 information is present in the executable, GDB will read it.
4956 * Multi-arched targets.
4958 DEC Alpha (partial) alpha*-*-*
4959 DEC VAX (partial) vax-*-*
4961 National Semiconductor NS32000 (partial) ns32k-*-*
4962 Motorola 68000 (partial) m68k-*-*
4963 Motorola MCORE mcore-*-*
4967 Fujitsu FRV architecture added by Red Hat frv*-*-*
4970 * New native configurations
4972 Alpha NetBSD alpha*-*-netbsd*
4973 SH NetBSD sh*-*-netbsdelf*
4974 MIPS NetBSD mips*-*-netbsd*
4975 UltraSPARC NetBSD sparc64-*-netbsd*
4977 * OBSOLETE configurations and files
4979 Configurations that have been declared obsolete in this release have
4980 been commented out. Unless there is activity to revive these
4981 configurations, the next release of GDB will have their sources
4982 permanently REMOVED.
4984 Mitsubishi D30V d30v-*-*
4985 OS/9000 i[34]86-*-os9k
4986 IBM AIX PS/2 i[3456]86-*-aix
4987 Fujitsu FR30 fr30-*-elf*
4988 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4989 Argonaut Risc Chip (ARC) arc-*-*
4990 i386 running Mach 3.0 i[3456]86-*-mach3*
4991 i386 running Mach i[3456]86-*-mach*
4992 i386 running OSF/1 i[3456]86-*osf1mk*
4993 HP/Apollo 68k Family m68*-apollo*-sysv*,
4995 m68*-hp-bsd*, m68*-hp-hpux*
4996 I960 with MON960 i960-*-coff
4998 * OBSOLETE languages
5000 CHILL, a Pascal like language used by telecommunications companies.
5002 * REMOVED configurations and files
5004 AMD 29k family via UDI a29k-amd-udi, udi29k
5005 A29K VxWorks a29k-*-vxworks
5006 AMD 29000 embedded, using EBMON a29k-none-none
5007 AMD 29000 embedded with COFF a29k-none-coff
5008 AMD 29000 embedded with a.out a29k-none-aout
5010 testsuite/gdb.hp/gdb.threads-hp/ directory
5012 * New command "set max-user-call-depth <nnn>"
5014 This command allows the user to limit the call depth of user-defined
5015 commands. The default is 1024.
5017 * Changes in FreeBSD/i386 native debugging.
5019 Support for the "generate-core-file" has been added.
5021 * New commands "dump", "append", and "restore".
5023 These commands allow data to be copied from target memory
5024 to a bfd-format or binary file (dump and append), and back
5025 from a file into memory (restore).
5027 * Improved "next/step" support on multi-processor Alpha Tru64.
5029 The previous single-step mechanism could cause unpredictable problems,
5030 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5031 of a software single-step mechanism prevents this.
5033 *** Changes in GDB 5.2.1:
5041 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5042 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5043 Fix, by Joel Brobecker imported from mainline.
5045 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5046 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5047 Fix, by Fred Fish, imported from mainline.
5049 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5050 Surprisingly enough, it works now.
5051 By Michal Ludvig, imported from mainline.
5053 i386 hardware watchpoint support:
5054 avoid misses on second run for some targets.
5055 By Pierre Muller, imported from mainline.
5057 *** Changes in GDB 5.2:
5059 * New command "set trust-readonly-sections on[off]".
5061 This command is a hint that tells gdb that read-only sections
5062 really are read-only (ie. that their contents will not change).
5063 In this mode, gdb will go to the object file rather than the
5064 target to read memory from read-only sections (such as ".text").
5065 This can be a significant performance improvement on some
5066 (notably embedded) targets.
5068 * New command "generate-core-file" (or "gcore").
5070 This new gdb command allows the user to drop a core file of the child
5071 process state at any time. So far it's been implemented only for
5072 GNU/Linux and Solaris, but should be relatively easily ported to other
5073 hosts. Argument is core file name (defaults to core.<pid>).
5075 * New command line option
5077 GDB now accepts --pid or -p followed by a process id.
5079 * Change in command line behavior -- corefiles vs. process ids.
5081 There is a subtle behavior in the way in which GDB handles
5082 command line arguments. The first non-flag argument is always
5083 a program to debug, but the second non-flag argument may either
5084 be a corefile or a process id. Previously, GDB would attempt to
5085 open the second argument as a corefile, and if that failed, would
5086 issue a superfluous error message and then attempt to attach it as
5087 a process. Now, if the second argument begins with a non-digit,
5088 it will be treated as a corefile. If it begins with a digit,
5089 GDB will attempt to attach it as a process, and if no such process
5090 is found, will then attempt to open it as a corefile.
5092 * Changes in ARM configurations.
5094 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5095 configuration is fully multi-arch.
5097 * New native configurations
5099 ARM NetBSD arm*-*-netbsd*
5100 x86 OpenBSD i[3456]86-*-openbsd*
5101 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5102 Sparc64 running FreeBSD sparc64-*-freebsd*
5106 Sanyo XStormy16 xstormy16-elf
5108 * OBSOLETE configurations and files
5110 Configurations that have been declared obsolete in this release have
5111 been commented out. Unless there is activity to revive these
5112 configurations, the next release of GDB will have their sources
5113 permanently REMOVED.
5115 AMD 29k family via UDI a29k-amd-udi, udi29k
5116 A29K VxWorks a29k-*-vxworks
5117 AMD 29000 embedded, using EBMON a29k-none-none
5118 AMD 29000 embedded with COFF a29k-none-coff
5119 AMD 29000 embedded with a.out a29k-none-aout
5121 testsuite/gdb.hp/gdb.threads-hp/ directory
5123 * REMOVED configurations and files
5125 TI TMS320C80 tic80-*-*
5127 PowerPC Solaris powerpcle-*-solaris*
5128 PowerPC Windows NT powerpcle-*-cygwin32
5129 PowerPC Netware powerpc-*-netware*
5130 Harris/CXUX m88k m88*-harris-cxux*
5131 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5132 ns32k-utek-sysv* ns32k-utek-*
5133 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5134 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5135 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5136 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5137 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5139 * Changes to command line processing
5141 The new `--args' feature can be used to specify command-line arguments
5142 for the inferior from gdb's command line.
5144 * Changes to key bindings
5146 There is a new `operate-and-get-next' function bound to `C-o'.
5148 *** Changes in GDB 5.1.1
5150 Fix compile problem on DJGPP.
5152 Fix a problem with floating-point registers on the i386 being
5155 Fix to stop GDB crashing on .debug_str debug info.
5157 Numerous documentation fixes.
5159 Numerous testsuite fixes.
5161 *** Changes in GDB 5.1:
5163 * New native configurations
5165 Alpha FreeBSD alpha*-*-freebsd*
5166 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5167 MIPS GNU/Linux mips*-*-linux*
5168 MIPS SGI Irix 6.x mips*-sgi-irix6*
5169 ia64 AIX ia64-*-aix*
5170 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5174 Motorola 68HC11 and 68HC12 m68hc11-elf
5176 UltraSparc running GNU/Linux sparc64-*-linux*
5178 * OBSOLETE configurations and files
5180 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5181 Harris/CXUX m88k m88*-harris-cxux*
5182 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5183 ns32k-utek-sysv* ns32k-utek-*
5184 TI TMS320C80 tic80-*-*
5186 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5187 PowerPC Solaris powerpcle-*-solaris*
5188 PowerPC Windows NT powerpcle-*-cygwin32
5189 PowerPC Netware powerpc-*-netware*
5190 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5191 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5192 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5193 Apple Macintosh (MPW) host N/A
5195 stuff.c (Program to stuff files into a specially prepared space in kdb)
5196 kdb-start.c (Main loop for the standalone kernel debugger)
5198 Configurations that have been declared obsolete in this release have
5199 been commented out. Unless there is activity to revive these
5200 configurations, the next release of GDB will have their sources
5201 permanently REMOVED.
5203 * REMOVED configurations and files
5205 Altos 3068 m68*-altos-*
5206 Convex c1-*-*, c2-*-*
5208 ARM RISCix arm-*-* (as host)
5212 * GDB has been converted to ISO C.
5214 GDB's source code has been converted to ISO C. In particular, the
5215 sources are fully protoized, and rely on standard headers being
5220 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5222 * The MI enabled by default.
5224 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5225 revised and enabled by default. Packages which use GDB as a debugging
5226 engine behind a UI or another front end are encouraged to switch to
5227 using the GDB/MI interface, instead of the old annotations interface
5228 which is now deprecated.
5230 * Support for debugging Pascal programs.
5232 GDB now includes support for debugging Pascal programs. The following
5233 main features are supported:
5235 - Pascal-specific data types such as sets;
5237 - automatic recognition of Pascal sources based on file-name
5240 - Pascal-style display of data types, variables, and functions;
5242 - a Pascal expression parser.
5244 However, some important features are not yet supported.
5246 - Pascal string operations are not supported at all;
5248 - there are some problems with boolean types;
5250 - Pascal type hexadecimal constants are not supported
5251 because they conflict with the internal variables format;
5253 - support for Pascal objects and classes is not full yet;
5255 - unlike Pascal, GDB is case-sensitive for symbol names.
5257 * Changes in completion.
5259 Commands such as `shell', `run' and `set args', which pass arguments
5260 to inferior programs, now complete on file names, similar to what
5261 users expect at the shell prompt.
5263 Commands which accept locations, such as `disassemble', `print',
5264 `breakpoint', `until', etc. now complete on filenames as well as
5265 program symbols. Thus, if you type "break foob TAB", and the source
5266 files linked into the programs include `foobar.c', that file name will
5267 be one of the candidates for completion. However, file names are not
5268 considered for completion after you typed a colon that delimits a file
5269 name from a name of a function in that file, as in "break foo.c:bar".
5271 `set demangle-style' completes on available demangling styles.
5273 * New platform-independent commands:
5275 It is now possible to define a post-hook for a command as well as a
5276 hook that runs before the command. For more details, see the
5277 documentation of `hookpost' in the GDB manual.
5279 * Changes in GNU/Linux native debugging.
5281 Support for debugging multi-threaded programs has been completely
5282 revised for all platforms except m68k and sparc. You can now debug as
5283 many threads as your system allows you to have.
5285 Attach/detach is supported for multi-threaded programs.
5287 Support for SSE registers was added for x86. This doesn't work for
5288 multi-threaded programs though.
5290 * Changes in MIPS configurations.
5292 Multi-arch support is enabled for all MIPS configurations.
5294 GDB can now be built as native debugger on SGI Irix 6.x systems for
5295 debugging n32 executables. (Debugging 64-bit executables is not yet
5298 * Unified support for hardware watchpoints in all x86 configurations.
5300 Most (if not all) native x86 configurations support hardware-assisted
5301 breakpoints and watchpoints in a unified manner. This support
5302 implements debug register sharing between watchpoints, which allows to
5303 put a virtually infinite number of watchpoints on the same address,
5304 and also supports watching regions up to 16 bytes with several debug
5307 The new maintenance command `maintenance show-debug-regs' toggles
5308 debugging print-outs in functions that insert, remove, and test
5309 watchpoints and hardware breakpoints.
5311 * Changes in the DJGPP native configuration.
5313 New command ``info dos sysinfo'' displays assorted information about
5314 the CPU, OS, memory, and DPMI server.
5316 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5317 display information about segment descriptors stored in GDT, LDT, and
5320 New commands ``info dos pde'' and ``info dos pte'' display entries
5321 from Page Directory and Page Tables (for now works with CWSDPMI only).
5322 New command ``info dos address-pte'' displays the Page Table entry for
5323 a given linear address.
5325 GDB can now pass command lines longer than 126 characters to the
5326 program being debugged (requires an update to the libdbg.a library
5327 which is part of the DJGPP development kit).
5329 DWARF2 debug info is now supported.
5331 It is now possible to `step' and `next' through calls to `longjmp'.
5333 * Changes in documentation.
5335 All GDB documentation was converted to GFDL, the GNU Free
5336 Documentation License.
5338 Tracepoints-related commands are now fully documented in the GDB
5341 TUI, the Text-mode User Interface, is now documented in the manual.
5343 Tracepoints-related commands are now fully documented in the GDB
5346 The "GDB Internals" manual now has an index. It also includes
5347 documentation of `ui_out' functions, GDB coding standards, x86
5348 hardware watchpoints, and memory region attributes.
5350 * GDB's version number moved to ``version.in''
5352 The Makefile variable VERSION has been replaced by the file
5353 ``version.in''. People creating GDB distributions should update the
5354 contents of this file.
5358 GUD support is now a standard part of the EMACS distribution.
5360 *** Changes in GDB 5.0:
5362 * Improved support for debugging FP programs on x86 targets
5364 Unified and much-improved support for debugging floating-point
5365 programs on all x86 targets. In particular, ``info float'' now
5366 displays the FP registers in the same format on all x86 targets, with
5367 greater level of detail.
5369 * Improvements and bugfixes in hardware-assisted watchpoints
5371 It is now possible to watch array elements, struct members, and
5372 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5373 on x86 targets no longer erroneously trigger when the address is
5376 * Improvements in the native DJGPP version of GDB
5378 The distribution now includes all the scripts and auxiliary files
5379 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5380 machines ``out of the box''.
5382 The DJGPP version can now debug programs that use signals. It is
5383 possible to catch signals that happened in the debuggee, deliver
5384 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5385 would kill the program being debugged.) Programs that hook hardware
5386 interrupts (keyboard, timer, etc.) can also be debugged.
5388 It is now possible to debug DJGPP programs that redirect their
5389 standard handles or switch them to raw (as opposed to cooked) mode, or
5390 even close them. The command ``run < foo > bar'' works as expected,
5391 and ``info terminal'' reports useful information about the debuggee's
5392 terminal, including raw/cooked mode, redirection, etc.
5394 The DJGPP version now uses termios functions for console I/O, which
5395 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5398 DOS-style file names with drive letters are now fully supported by
5401 It is now possible to debug DJGPP programs that switch their working
5402 directory. It is also possible to rerun the debuggee any number of
5403 times without restarting GDB; thus, you can use the same setup,
5404 breakpoints, etc. for many debugging sessions.
5406 * New native configurations
5408 ARM GNU/Linux arm*-*-linux*
5409 PowerPC GNU/Linux powerpc-*-linux*
5413 Motorola MCore mcore-*-*
5414 x86 VxWorks i[3456]86-*-vxworks*
5415 PowerPC VxWorks powerpc-*-vxworks*
5416 TI TMS320C80 tic80-*-*
5418 * OBSOLETE configurations
5420 Altos 3068 m68*-altos-*
5421 Convex c1-*-*, c2-*-*
5423 ARM RISCix arm-*-* (as host)
5426 Configurations that have been declared obsolete will be commented out,
5427 but the code will be left in place. If there is no activity to revive
5428 these configurations before the next release of GDB, the sources will
5429 be permanently REMOVED.
5431 * Gould support removed
5433 Support for the Gould PowerNode and NP1 has been removed.
5435 * New features for SVR4
5437 On SVR4 native platforms (such as Solaris), if you attach to a process
5438 without first loading a symbol file, GDB will now attempt to locate and
5439 load symbols from the running process's executable file.
5441 * Many C++ enhancements
5443 C++ support has been greatly improved. Overload resolution now works properly
5444 in almost all cases. RTTI support is on the way.
5446 * Remote targets can connect to a sub-program
5448 A popen(3) style serial-device has been added. This device starts a
5449 sub-process (such as a stand-alone simulator) and then communicates
5450 with that. The sub-program to run is specified using the syntax
5451 ``|<program> <args>'' vis:
5453 (gdb) set remotedebug 1
5454 (gdb) target extended-remote |mn10300-elf-sim program-args
5456 * MIPS 64 remote protocol
5458 A long standing bug in the mips64 remote protocol where by GDB
5459 expected certain 32 bit registers (ex SR) to be transfered as 32
5460 instead of 64 bits has been fixed.
5462 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5463 added to provide backward compatibility with older versions of GDB.
5465 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5467 The command ``set remotebinarydownload'' command has been replaced by
5468 ``set remote X-packet''. Other commands in ``set remote'' family
5469 include ``set remote P-packet''.
5471 * Breakpoint commands accept ranges.
5473 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5474 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5475 ``tracepoint passcount'' also accepts a range of tracepoints.
5477 * ``apropos'' command added.
5479 The ``apropos'' command searches through command names and
5480 documentation strings, printing out matches, making it much easier to
5481 try to find a command that does what you are looking for.
5485 A new machine oriented interface (MI) has been added to GDB. This
5486 interface is designed for debug environments running GDB as a separate
5487 process. This is part of the long term libGDB project. See the
5488 "GDB/MI" chapter of the GDB manual for further information. It can be
5489 enabled by configuring with:
5491 .../configure --enable-gdbmi
5493 *** Changes in GDB-4.18:
5495 * New native configurations
5497 HP-UX 10.20 hppa*-*-hpux10.20
5498 HP-UX 11.x hppa*-*-hpux11.0*
5499 M68K GNU/Linux m68*-*-linux*
5503 Fujitsu FR30 fr30-*-elf*
5504 Intel StrongARM strongarm-*-*
5505 Mitsubishi D30V d30v-*-*
5507 * OBSOLETE configurations
5509 Gould PowerNode, NP1 np1-*-*, pn-*-*
5511 Configurations that have been declared obsolete will be commented out,
5512 but the code will be left in place. If there is no activity to revive
5513 these configurations before the next release of GDB, the sources will
5514 be permanently REMOVED.
5518 As a compatibility experiment, GDB's source files buildsym.h and
5519 buildsym.c have been converted to pure standard C, no longer
5520 containing any K&R compatibility code. We believe that all systems in
5521 use today either come with a standard C compiler, or have a GCC port
5522 available. If this is not true, please report the affected
5523 configuration to bug-gdb@gnu.org immediately. See the README file for
5524 information about getting a standard C compiler if you don't have one
5529 GDB now uses readline 2.2.
5531 * set extension-language
5533 You can now control the mapping between filename extensions and source
5534 languages by using the `set extension-language' command. For instance,
5535 you can ask GDB to treat .c files as C++ by saying
5536 set extension-language .c c++
5537 The command `info extensions' lists all of the recognized extensions
5538 and their associated languages.
5540 * Setting processor type for PowerPC and RS/6000
5542 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5543 you can use the `set processor' command to specify what variant of the
5544 PowerPC family you are debugging. The command
5548 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5549 following PowerPC and RS6000 variants:
5551 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5552 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5554 403GC IBM PowerPC 403GC
5555 505 Motorola PowerPC 505
5556 860 Motorola PowerPC 860 or 850
5557 601 Motorola PowerPC 601
5558 602 Motorola PowerPC 602
5559 603 Motorola/IBM PowerPC 603 or 603e
5560 604 Motorola PowerPC 604 or 604e
5561 750 Motorola/IBM PowerPC 750 or 750
5563 At the moment, this command just tells GDB what to name the
5564 special-purpose processor registers. Since almost all the affected
5565 registers are inaccessible to user-level programs, this command is
5566 only useful for remote debugging in its present form.
5570 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5571 more extensive support for HP-UX. Added features include shared
5572 library support, kernel threads and hardware watchpoints for 11.00,
5573 support for HP's ANSI C and C++ compilers, and a compatibility mode
5574 for xdb and dbx commands.
5578 HP's donation includes the new concept of catchpoints, which is a
5579 generalization of the old catch command. On HP-UX, it is now possible
5580 to catch exec, fork, and vfork, as well as library loading.
5582 This means that the existing catch command has changed; its first
5583 argument now specifies the type of catch to be set up. See the
5584 output of "help catch" for a list of catchpoint types.
5586 * Debugging across forks
5588 On HP-UX, you can choose which process to debug when a fork() happens
5593 HP has donated a curses-based terminal user interface (TUI). To get
5594 it, build with --enable-tui. Although this can be enabled for any
5595 configuration, at present it only works for native HP debugging.
5597 * GDB remote protocol additions
5599 A new protocol packet 'X' that writes binary data is now available.
5600 Default behavior is to try 'X', then drop back to 'M' if the stub
5601 fails to respond. The settable variable `remotebinarydownload'
5602 allows explicit control over the use of 'X'.
5604 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5605 full 64-bit address. The command
5607 set remoteaddresssize 32
5609 can be used to revert to the old behaviour. For existing remote stubs
5610 the change should not be noticed, as the additional address information
5613 In order to assist in debugging stubs, you may use the maintenance
5614 command `packet' to send any text string to the stub. For instance,
5616 maint packet heythere
5618 sends the packet "$heythere#<checksum>". Note that it is very easy to
5619 disrupt a debugging session by sending the wrong packet at the wrong
5622 The compare-sections command allows you to compare section data on the
5623 target to what is in the executable file without uploading or
5624 downloading, by comparing CRC checksums.
5626 * Tracing can collect general expressions
5628 You may now collect general expressions at tracepoints. This requires
5629 further additions to the target-side stub; see tracepoint.c and
5630 doc/agentexpr.texi for further details.
5632 * mask-address variable for Mips
5634 For Mips targets, you may control the zeroing of the upper 32 bits of
5635 a 64-bit address by entering `set mask-address on'. This is mainly
5636 of interest to users of embedded R4xxx and R5xxx processors.
5638 * Higher serial baud rates
5640 GDB's serial code now allows you to specify baud rates 57600, 115200,
5641 230400, and 460800 baud. (Note that your host system may not be able
5642 to achieve all of these rates.)
5646 The i960 configuration now includes an initial implementation of a
5647 builtin simulator, contributed by Jim Wilson.
5650 *** Changes in GDB-4.17:
5652 * New native configurations
5654 Alpha GNU/Linux alpha*-*-linux*
5655 Unixware 2.x i[3456]86-unixware2*
5656 Irix 6.x mips*-sgi-irix6*
5657 PowerPC GNU/Linux powerpc-*-linux*
5658 PowerPC Solaris powerpcle-*-solaris*
5659 Sparc GNU/Linux sparc-*-linux*
5660 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5664 Argonaut Risc Chip (ARC) arc-*-*
5665 Hitachi H8/300S h8300*-*-*
5666 Matsushita MN10200 w/simulator mn10200-*-*
5667 Matsushita MN10300 w/simulator mn10300-*-*
5668 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5669 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5670 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5671 Mitsubishi D10V w/simulator d10v-*-*
5672 Mitsubishi M32R/D w/simulator m32r-*-elf*
5673 Tsqware Sparclet sparclet-*-*
5674 NEC V850 w/simulator v850-*-*
5676 * New debugging protocols
5678 ARM with RDI protocol arm*-*-*
5679 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5680 DDB and LSI variants of PMON protocol mips*-*-*
5681 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5682 PowerPC with SDS protocol powerpc{,le}-*-eabi
5683 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5687 All configurations can now understand and use the DWARF 2 debugging
5688 format. The choice is automatic, if the symbol file contains DWARF 2
5693 GDB now includes basic Java language support. This support is
5694 only useful with Java compilers that produce native machine code.
5696 * solib-absolute-prefix and solib-search-path
5698 For SunOS and SVR4 shared libraries, you may now set the prefix for
5699 loading absolute shared library symbol files, and the search path for
5700 locating non-absolute shared library symbol files.
5702 * Live range splitting
5704 GDB can now effectively debug code for which GCC has performed live
5705 range splitting as part of its optimization. See gdb/doc/LRS for
5706 more details on the expected format of the stabs information.
5710 GDB's support for the GNU Hurd, including thread debugging, has been
5711 updated to work with current versions of the Hurd.
5715 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5716 instruction set. ARM GDB automatically detects when Thumb
5717 instructions are in use, and adjusts disassembly and backtracing
5722 GDB's MIPS target configurations now handle the MIP16 16-bit
5727 GDB now includes support for overlays; if an executable has been
5728 linked such that multiple sections are based at the same address, GDB
5729 will decide which section to use for symbolic info. You can choose to
5730 control the decision manually, using overlay commands, or implement
5731 additional target-side support and use "overlay load-target" to bring
5732 in the overlay mapping. Do "help overlay" for more detail.
5736 The command "info symbol <address>" displays information about
5737 the symbol at the specified address.
5741 The standard remote protocol now includes an extension that allows
5742 asynchronous collection and display of trace data. This requires
5743 extensive support in the target-side debugging stub. Tracing mode
5744 includes a new interaction mode in GDB and new commands: see the
5745 file tracepoint.c for more details.
5749 Configurations for embedded MIPS now include a simulator contributed
5750 by Cygnus Solutions. The simulator supports the instruction sets
5751 of most MIPS variants.
5755 Sparc configurations may now include the ERC32 simulator contributed
5756 by the European Space Agency. The simulator is not built into
5757 Sparc targets by default; configure with --enable-sim to include it.
5761 For target configurations that may include multiple variants of a
5762 basic architecture (such as MIPS and SH), you may now set the
5763 architecture explicitly. "set arch" sets, "info arch" lists
5764 the possible architectures.
5766 *** Changes in GDB-4.16:
5768 * New native configurations
5770 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5771 M68K NetBSD m68k-*-netbsd*
5772 PowerPC AIX 4.x powerpc-*-aix*
5773 PowerPC MacOS powerpc-*-macos*
5774 PowerPC Windows NT powerpcle-*-cygwin32
5775 RS/6000 AIX 4.x rs6000-*-aix4*
5779 ARM with RDP protocol arm-*-*
5780 I960 with MON960 i960-*-coff
5781 MIPS VxWorks mips*-*-vxworks*
5782 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5783 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5785 Matra Sparclet sparclet-*-*
5789 The powerpc-eabi configuration now includes the PSIM simulator,
5790 contributed by Andrew Cagney, with assistance from Mike Meissner.
5791 PSIM is a very elaborate model of the PowerPC, including not only
5792 basic instruction set execution, but also details of execution unit
5793 performance and I/O hardware. See sim/ppc/README for more details.
5797 GDB now works with Solaris 2.5.
5799 * Windows 95/NT native
5801 GDB will now work as a native debugger on Windows 95 and Windows NT.
5802 To build it from source, you must use the "gnu-win32" environment,
5803 which uses a DLL to emulate enough of Unix to run the GNU tools.
5804 Further information, binaries, and sources are available at
5805 ftp.cygnus.com, under pub/gnu-win32.
5807 * dont-repeat command
5809 If a user-defined command includes the command `dont-repeat', then the
5810 command will not be repeated if the user just types return. This is
5811 useful if the command is time-consuming to run, so that accidental
5812 extra keystrokes don't run the same command many times.
5814 * Send break instead of ^C
5816 The standard remote protocol now includes an option to send a break
5817 rather than a ^C to the target in order to interrupt it. By default,
5818 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5820 * Remote protocol timeout
5822 The standard remote protocol includes a new variable `remotetimeout'
5823 that allows you to set the number of seconds before GDB gives up trying
5824 to read from the target. The default value is 2.
5826 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5828 By default GDB will automatically keep track of objects as they are
5829 loaded and unloaded by the dynamic linker. By using the command `set
5830 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5831 when shared library events occur, thus allowing you to set breakpoints
5832 in shared libraries which are explicitly loaded by the inferior.
5834 Note this feature does not work on hpux8. On hpux9 you must link
5835 /usr/lib/end.o into your program. This feature should work
5836 automatically on hpux10.
5838 * Irix 5.x hardware watchpoint support
5840 Irix 5 configurations now support the use of hardware watchpoints.
5842 * Mips protocol "SYN garbage limit"
5844 When debugging a Mips target using the `target mips' protocol, you
5845 may set the number of characters that GDB will ignore by setting
5846 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5847 every character. The default value is 1050.
5849 * Recording and replaying remote debug sessions
5851 If you set `remotelogfile' to the name of a file, gdb will write to it
5852 a recording of a remote debug session. This recording may then be
5853 replayed back to gdb using "gdbreplay". See gdbserver/README for
5854 details. This is useful when you have a problem with GDB while doing
5855 remote debugging; you can make a recording of the session and send it
5856 to someone else, who can then recreate the problem.
5858 * Speedups for remote debugging
5860 GDB includes speedups for downloading and stepping MIPS systems using
5861 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5862 and more efficient S-record downloading.
5864 * Memory use reductions and statistics collection
5866 GDB now uses less memory and reports statistics about memory usage.
5867 Try the `maint print statistics' command, for example.
5869 *** Changes in GDB-4.15:
5871 * Psymtabs for XCOFF
5873 The symbol reader for AIX GDB now uses partial symbol tables. This
5874 can greatly improve startup time, especially for large executables.
5876 * Remote targets use caching
5878 Remote targets now use a data cache to speed up communication with the
5879 remote side. The data cache could lead to incorrect results because
5880 it doesn't know about volatile variables, thus making it impossible to
5881 debug targets which use memory mapped I/O devices. `set remotecache
5882 off' turns the the data cache off.
5884 * Remote targets may have threads
5886 The standard remote protocol now includes support for multiple threads
5887 in the target system, using new protocol commands 'H' and 'T'. See
5888 gdb/remote.c for details.
5892 If GDB is configured with `--enable-netrom', then it will include
5893 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5894 acts as though it is a bank of ROM on the target board, but you can
5895 write into it over the network. GDB's support consists only of
5896 support for fast loading into the emulated ROM; to debug, you must use
5897 another protocol, such as standard remote protocol. The usual
5898 sequence is something like
5900 target nrom <netrom-hostname>
5902 target remote <netrom-hostname>:1235
5906 GDB now includes support for the Apple Macintosh, as a host only. It
5907 may be run as either an MPW tool or as a standalone application, and
5908 it can debug through the serial port. All the usual GDB commands are
5909 available, but to the target command, you must supply "serial" as the
5910 device type instead of "/dev/ttyXX". See mpw-README in the main
5911 directory for more information on how to build. The MPW configuration
5912 scripts */mpw-config.in support only a few targets, and only the
5913 mips-idt-ecoff target has been tested.
5917 GDB configuration now uses autoconf. This is not user-visible,
5918 but does simplify configuration and building.
5922 GDB now supports hpux10.
5924 *** Changes in GDB-4.14:
5926 * New native configurations
5928 x86 FreeBSD i[345]86-*-freebsd
5929 x86 NetBSD i[345]86-*-netbsd
5930 NS32k NetBSD ns32k-*-netbsd
5931 Sparc NetBSD sparc-*-netbsd
5935 A29K VxWorks a29k-*-vxworks
5936 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5937 CPU32 EST-300 emulator m68*-*-est*
5938 PowerPC ELF powerpc-*-elf
5941 * Alpha OSF/1 support for procfs
5943 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5944 possible to attach to running processes. As the mounting of the /proc
5945 filesystem is optional on the Alpha, GDB automatically determines
5946 the availability of /proc during startup. This can lead to problems
5947 if /proc is unmounted after GDB has been started.
5949 * Arguments to user-defined commands
5951 User commands may accept up to 10 arguments separated by whitespace.
5952 Arguments are accessed within the user command via $arg0..$arg9. A
5955 print $arg0 + $arg1 + $arg2
5957 To execute the command use:
5960 Defines the command "adder" which prints the sum of its three arguments.
5961 Note the arguments are text substitutions, so they may reference variables,
5962 use complex expressions, or even perform inferior function calls.
5964 * New `if' and `while' commands
5966 This makes it possible to write more sophisticated user-defined
5967 commands. Both commands take a single argument, which is the
5968 expression to evaluate, and must be followed by the commands to
5969 execute, one per line, if the expression is nonzero, the list being
5970 terminated by the word `end'. The `if' command list may include an
5971 `else' word, which causes the following commands to be executed only
5972 if the expression is zero.
5974 * Fortran source language mode
5976 GDB now includes partial support for Fortran 77. It will recognize
5977 Fortran programs and can evaluate a subset of Fortran expressions, but
5978 variables and functions may not be handled correctly. GDB will work
5979 with G77, but does not yet know much about symbols emitted by other
5982 * Better HPUX support
5984 Most debugging facilities now work on dynamic executables for HPPAs
5985 running hpux9 or later. You can attach to running dynamically linked
5986 processes, but by default the dynamic libraries will be read-only, so
5987 for instance you won't be able to put breakpoints in them. To change
5988 that behavior do the following before running the program:
5994 This will cause the libraries to be mapped private and read-write.
5995 To revert to the normal behavior, do this:
6001 You cannot set breakpoints or examine data in the library until after
6002 the library is loaded if the function/data symbols do not have
6005 GDB can now also read debug symbols produced by the HP C compiler on
6006 HPPAs (sorry, no C++, Fortran or 68k support).
6008 * Target byte order now dynamically selectable
6010 You can choose which byte order to use with a target system, via the
6011 commands "set endian big" and "set endian little", and you can see the
6012 current setting by using "show endian". You can also give the command
6013 "set endian auto", in which case GDB will use the byte order
6014 associated with the executable. Currently, only embedded MIPS
6015 configurations support dynamic selection of target byte order.
6017 * New DOS host serial code
6019 This version uses DPMI interrupts to handle buffered I/O, so you
6020 no longer need to run asynctsr when debugging boards connected to
6023 *** Changes in GDB-4.13:
6025 * New "complete" command
6027 This lists all the possible completions for the rest of the line, if it
6028 were to be given as a command itself. This is intended for use by emacs.
6030 * Trailing space optional in prompt
6032 "set prompt" no longer adds a space for you after the prompt you set. This
6033 allows you to set a prompt which ends in a space or one that does not.
6035 * Breakpoint hit counts
6037 "info break" now displays a count of the number of times the breakpoint
6038 has been hit. This is especially useful in conjunction with "ignore"; you
6039 can ignore a large number of breakpoint hits, look at the breakpoint info
6040 to see how many times the breakpoint was hit, then run again, ignoring one
6041 less than that number, and this will get you quickly to the last hit of
6044 * Ability to stop printing at NULL character
6046 "set print null-stop" will cause GDB to stop printing the characters of
6047 an array when the first NULL is encountered. This is useful when large
6048 arrays actually contain only short strings.
6050 * Shared library breakpoints
6052 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6053 breakpoints in shared libraries before the executable is run.
6055 * Hardware watchpoints
6057 There is a new hardware breakpoint for the watch command for sparclite
6058 targets. See gdb/sparclite/hw_breakpoint.note.
6060 Hardware watchpoints are also now supported under GNU/Linux.
6064 Annotations have been added. These are for use with graphical interfaces,
6065 and are still experimental. Currently only gdba.el uses these.
6067 * Improved Irix 5 support
6069 GDB now works properly with Irix 5.2.
6071 * Improved HPPA support
6073 GDB now works properly with the latest GCC and GAS.
6075 * New native configurations
6077 Sequent PTX4 i[34]86-sequent-ptx4
6078 HPPA running OSF/1 hppa*-*-osf*
6079 Atari TT running SVR4 m68*-*-sysv4*
6080 RS/6000 LynxOS rs6000-*-lynxos*
6084 OS/9000 i[34]86-*-os9k
6085 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6088 * Hitachi SH7000 and E7000-PC ICE support
6090 There is now support for communicating with the Hitachi E7000-PC ICE.
6091 This is available automatically when GDB is configured for the SH.
6095 As usual, a variety of small fixes and improvements, both generic
6096 and configuration-specific. See the ChangeLog for more detail.
6098 *** Changes in GDB-4.12:
6100 * Irix 5 is now supported
6104 GDB-4.12 on the HPPA has a number of changes which make it unable
6105 to debug the output from the currently released versions of GCC and
6106 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6107 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6108 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6111 *** Changes in GDB-4.11:
6113 * User visible changes:
6117 The "set remotedebug" option is now consistent between the mips remote
6118 target, remote targets using the gdb-specific protocol, UDI (AMD's
6119 debug protocol for the 29k) and the 88k bug monitor. It is now an
6120 integer specifying a debug level (normally 0 or 1, but 2 means more
6121 debugging info for the mips target).
6123 * DEC Alpha native support
6125 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6126 debug info, but GDB works fairly well with the DEC compiler and should
6127 work with a future GCC release. See the README file for a few
6128 Alpha-specific notes.
6130 * Preliminary thread implementation
6132 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6134 * LynxOS native and target support for 386
6136 This release has been hosted on LynxOS 2.2, and also can be configured
6137 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6140 * Improvements in C++ mangling/demangling.
6142 This release has much better g++ debugging, specifically in name
6143 mangling/demangling, virtual function calls, print virtual table,
6144 call methods, ...etc.
6146 *** Changes in GDB-4.10:
6148 * User visible changes:
6150 Remote debugging using the GDB-specific (`target remote') protocol now
6151 supports the `load' command. This is only useful if you have some
6152 other way of getting the stub to the target system, and you can put it
6153 somewhere in memory where it won't get clobbered by the download.
6155 Filename completion now works.
6157 When run under emacs mode, the "info line" command now causes the
6158 arrow to point to the line specified. Also, "info line" prints
6159 addresses in symbolic form (as well as hex).
6161 All vxworks based targets now support a user settable option, called
6162 vxworks-timeout. This option represents the number of seconds gdb
6163 should wait for responses to rpc's. You might want to use this if
6164 your vxworks target is, perhaps, a slow software simulator or happens
6165 to be on the far side of a thin network line.
6169 This release contains support for using a DEC alpha as a GDB host for
6170 cross debugging. Native alpha debugging is not supported yet.
6173 *** Changes in GDB-4.9:
6177 This is the first GDB release which is accompanied by a matching testsuite.
6178 The testsuite requires installation of dejagnu, which should be available
6179 via ftp from most sites that carry GNU software.
6183 'Cfront' style demangling has had its name changed to 'ARM' style, to
6184 emphasize that it was written from the specifications in the C++ Annotated
6185 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6186 disclaimers, it still generated too much confusion with users attempting to
6187 use gdb with AT&T cfront.
6191 GDB now uses a standard remote interface to a simulator library.
6192 So far, the library contains simulators for the Zilog Z8001/2, the
6193 Hitachi H8/300, H8/500 and Super-H.
6195 * New targets supported
6197 H8/300 simulator h8300-hitachi-hms or h8300hms
6198 H8/500 simulator h8500-hitachi-hms or h8500hms
6199 SH simulator sh-hitachi-hms or sh
6200 Z8000 simulator z8k-zilog-none or z8ksim
6201 IDT MIPS board over serial line mips-idt-ecoff
6203 Cross-debugging to GO32 targets is supported. It requires a custom
6204 version of the i386-stub.c module which is integrated with the
6205 GO32 memory extender.
6207 * New remote protocols
6209 MIPS remote debugging protocol.
6211 * New source languages supported
6213 This version includes preliminary support for Chill, a Pascal like language
6214 used by telecommunications companies. Chill support is also being integrated
6215 into the GNU compiler, but we don't know when it will be publically available.
6218 *** Changes in GDB-4.8:
6220 * HP Precision Architecture supported
6222 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6223 version of this support was available as a set of patches from the
6224 University of Utah. GDB does not support debugging of programs
6225 compiled with the HP compiler, because HP will not document their file
6226 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6227 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6229 Many problems in the preliminary version have been fixed.
6231 * Faster and better demangling
6233 We have improved template demangling and fixed numerous bugs in the GNU style
6234 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6235 character types (wchar_t) are now supported. Demangling of each symbol is now
6236 only done once, and is cached when the symbol table for a file is read in.
6237 This results in a small increase in memory usage for C programs, a moderate
6238 increase in memory usage for C++ programs, and a fantastic speedup in
6241 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6242 from the specifications in the Annotated Reference Manual, which AT&T's
6243 compiler does not actually implement.
6245 * G++ multiple inheritance compiler problem
6247 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6248 inheritance lattices was reworked to properly discover ambiguities. We
6249 recently found an example which causes this new algorithm to fail in a
6250 very subtle way, producing bad debug information for those classes.
6251 The file 'gcc.patch' (in this directory) can be applied to gcc to
6252 circumvent the problem. A future GCC release will contain a complete
6255 The previous G++ debug info problem (mentioned below for the gdb-4.7
6256 release) is fixed in gcc version 2.3.2.
6258 * Improved configure script
6260 The `configure' script will now attempt to guess your system type if
6261 you don't supply a host system type. The old scheme of supplying a
6262 host system triplet is preferable over using this. All the magic is
6263 done in the new `config.guess' script. Examine it for details.
6265 We have also brought our configure script much more in line with the FSF's
6266 version. It now supports the --with-xxx options. In particular,
6267 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6268 The resulting GDB will not be able to read arbitrary object file formats --
6269 only the format ``expected'' to be used on the configured target system.
6270 We hope to make this the default in a future release.
6272 * Documentation improvements
6274 There's new internal documentation on how to modify GDB, and how to
6275 produce clean changes to the code. We implore people to read it
6276 before submitting changes.
6278 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6279 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6280 `info' files are also provided. To build `info' files from scratch,
6281 you will need the latest `makeinfo' release, which will be available in
6282 a future texinfo-X.Y release.
6284 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6285 We're not sure exactly which versions have this problem, but it has
6286 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6287 or better. If that isn't possible, there is a patch in
6288 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6289 around this problem.
6293 GDB now supports array constants that can be used in expressions typed in by
6294 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6295 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6298 The new directory `gdb/sparclite' contains a program that demonstrates
6299 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6301 * New native hosts supported
6303 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6304 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6306 * New targets supported
6308 AMD 29k family via UDI a29k-amd-udi or udi29k
6310 * New file formats supported
6312 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6313 HPUX core files, and SCO 3.2v2 core files.
6317 Attaching to processes now works again; thanks for the many bug reports.
6319 We have also stomped on a bunch of core dumps caused by
6320 printf_filtered("%s") problems.
6322 We eliminated a copyright problem on the rpc and ptrace header files
6323 for VxWorks, which was discovered at the last minute during the 4.7
6324 release. You should now be able to build a VxWorks GDB.
6326 You can now interrupt gdb while an attached process is running. This
6327 will cause the attached process to stop, and give control back to GDB.
6329 We fixed problems caused by using too many file descriptors
6330 for reading symbols from object files and libraries. This was
6331 especially a problem for programs that used many (~100) shared
6334 The `step' command now only enters a subroutine if there is line number
6335 information for the subroutine. Otherwise it acts like the `next'
6336 command. Previously, `step' would enter subroutines if there was
6337 any debugging information about the routine. This avoids problems
6338 when using `cc -g1' on MIPS machines.
6340 * Internal improvements
6342 GDB's internal interfaces have been improved to make it easier to support
6343 debugging of multiple languages in the future.
6345 GDB now uses a common structure for symbol information internally.
6346 Minimal symbols (derived from linkage symbols in object files), partial
6347 symbols (from a quick scan of debug information), and full symbols
6348 contain a common subset of information, making it easier to write
6349 shared code that handles any of them.
6351 * New command line options
6353 We now accept --silent as an alias for --quiet.
6357 The memory-mapped-malloc library is now licensed under the GNU Library
6358 General Public License.
6360 *** Changes in GDB-4.7:
6362 * Host/native/target split
6364 GDB has had some major internal surgery to untangle the support for
6365 hosts and remote targets. Now, when you configure GDB for a remote
6366 target, it will no longer load in all of the support for debugging
6367 local programs on the host. When fully completed and tested, this will
6368 ensure that arbitrary host/target combinations are possible.
6370 The primary conceptual shift is to separate the non-portable code in
6371 GDB into three categories. Host specific code is required any time GDB
6372 is compiled on that host, regardless of the target. Target specific
6373 code relates to the peculiarities of the target, but can be compiled on
6374 any host. Native specific code is everything else: it can only be
6375 built when the host and target are the same system. Child process
6376 handling and core file support are two common `native' examples.
6378 GDB's use of /proc for controlling Unix child processes is now cleaner.
6379 It has been split out into a single module under the `target_ops' vector,
6380 plus two native-dependent functions for each system that uses /proc.
6382 * New hosts supported
6384 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6385 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6386 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6388 * New targets supported
6390 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6391 68030 and CPU32 m68030-*-*, m68332-*-*
6393 * New native hosts supported
6395 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6396 (386bsd is not well tested yet)
6397 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6399 * New file formats supported
6401 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6402 supports reading of `a.out.adobe' object files, which are an a.out
6403 format extended with minimal information about multiple sections.
6407 `show copying' is the same as the old `info copying'.
6408 `show warranty' is the same as `info warrantee'.
6409 These were renamed for consistency. The old commands continue to work.
6411 `info handle' is a new alias for `info signals'.
6413 You can now define pre-command hooks, which attach arbitrary command
6414 scripts to any command. The commands in the hook will be executed
6415 prior to the user's command. You can also create a hook which will be
6416 executed whenever the program stops. See gdb.texinfo.
6420 We now deal with Cfront style name mangling, and can even extract type
6421 info from mangled symbols. GDB can automatically figure out which
6422 symbol mangling style your C++ compiler uses.
6424 Calling of methods and virtual functions has been improved as well.
6428 The crash that occured when debugging Sun Ansi-C compiled binaries is
6429 fixed. This was due to mishandling of the extra N_SO stabs output
6432 We also finally got Ultrix 4.2 running in house, and fixed core file
6433 support, with help from a dozen people on the net.
6435 John M. Farrell discovered that the reason that single-stepping was so
6436 slow on all of the Mips based platforms (primarily SGI and DEC) was
6437 that we were trying to demangle and lookup a symbol used for internal
6438 purposes on every instruction that was being stepped through. Changing
6439 the name of that symbol so that it couldn't be mistaken for a C++
6440 mangled symbol sped things up a great deal.
6442 Rich Pixley sped up symbol lookups in general by getting much smarter
6443 about when C++ symbol mangling is necessary. This should make symbol
6444 completion (TAB on the command line) much faster. It's not as fast as
6445 we'd like, but it's significantly faster than gdb-4.6.
6449 A new user controllable variable 'call_scratch_address' can
6450 specify the location of a scratch area to be used when GDB
6451 calls a function in the target. This is necessary because the
6452 usual method of putting the scratch area on the stack does not work
6453 in systems that have separate instruction and data spaces.
6455 We integrated changes to support the 29k UDI (Universal Debugger
6456 Interface), but discovered at the last minute that we didn't have all
6457 of the appropriate copyright paperwork. We are working with AMD to
6458 resolve this, and hope to have it available soon.
6462 We have sped up the remote serial line protocol, especially for targets
6463 with lots of registers. It now supports a new `expedited status' ('T')
6464 message which can be used in place of the existing 'S' status message.
6465 This allows the remote stub to send only the registers that GDB
6466 needs to make a quick decision about single-stepping or conditional
6467 breakpoints, eliminating the need to fetch the entire register set for
6468 each instruction being stepped through.
6470 The GDB remote serial protocol now implements a write-through cache for
6471 registers, only re-reading the registers if the target has run.
6473 There is also a new remote serial stub for SPARC processors. You can
6474 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6475 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6476 processor with a serial port.
6480 Configure.in files have become much easier to read and modify. A new
6481 `table driven' format makes it more obvious what configurations are
6482 supported, and what files each one uses.
6486 There is a new opcodes library which will eventually contain all of the
6487 disassembly routines and opcode tables. At present, it only contains
6488 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6489 disassembler (binutils/objdump) to share these routines.
6491 The libiberty library is now copylefted under the GNU Library General
6492 Public License. This allows more liberal use, and was done so libg++
6493 can use it. This makes no difference to GDB, since the Library License
6494 grants all the rights from the General Public License.
6498 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6499 reference to the stabs symbol info used by the debugger. It is (as far
6500 as we know) the only published document on this fascinating topic. We
6501 encourage you to read it, compare it to the stabs information on your
6502 system, and send improvements on the document in general (to
6503 bug-gdb@prep.ai.mit.edu).
6505 And, of course, many bugs have been fixed.
6508 *** Changes in GDB-4.6:
6510 * Better support for C++ function names
6512 GDB now accepts as input the "demangled form" of C++ overloaded function
6513 names and member function names, and can do command completion on such names
6514 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6515 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6516 Make use of command completion, it is your friend.
6518 GDB also now accepts a variety of C++ mangled symbol formats. They are
6519 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6520 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6521 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6522 for the list of formats.
6524 * G++ symbol mangling problem
6526 Recent versions of gcc have a bug in how they emit debugging information for
6527 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6528 directory) can be applied to gcc to fix the problem. Alternatively, if you
6529 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6530 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6531 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6534 * New 'maintenance' command
6536 All of the commands related to hacking GDB internals have been moved out of
6537 the main command set, and now live behind the 'maintenance' command. This
6538 can also be abbreviated as 'mt'. The following changes were made:
6540 dump-me -> maintenance dump-me
6541 info all-breakpoints -> maintenance info breakpoints
6542 printmsyms -> maintenance print msyms
6543 printobjfiles -> maintenance print objfiles
6544 printpsyms -> maintenance print psymbols
6545 printsyms -> maintenance print symbols
6547 The following commands are new:
6549 maintenance demangle Call internal GDB demangler routine to
6550 demangle a C++ link name and prints the result.
6551 maintenance print type Print a type chain for a given symbol
6553 * Change to .gdbinit file processing
6555 We now read the $HOME/.gdbinit file before processing the argv arguments
6556 (e.g. reading symbol files or core files). This allows global parameters to
6557 be set, which will apply during the symbol reading. The ./.gdbinit is still
6558 read after argv processing.
6560 * New hosts supported
6562 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6564 GNU/Linux support i386-unknown-linux or linux
6566 We are also including code to support the HP/PA running BSD and HPUX. This
6567 is almost guaranteed not to work, as we didn't have time to test or build it
6568 for this release. We are including it so that the more adventurous (or
6569 masochistic) of you can play with it. We also had major problems with the
6570 fact that the compiler that we got from HP doesn't support the -g option.
6573 * New targets supported
6575 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6577 * More smarts about finding #include files
6579 GDB now remembers the compilation directory for all include files, and for
6580 all files from which C is generated (like yacc and lex sources). This
6581 greatly improves GDB's ability to find yacc/lex sources, and include files,
6582 especially if you are debugging your program from a directory different from
6583 the one that contains your sources.
6585 We also fixed a bug which caused difficulty with listing and setting
6586 breakpoints in include files which contain C code. (In the past, you had to
6587 try twice in order to list an include file that you hadn't looked at before.)
6589 * Interesting infernals change
6591 GDB now deals with arbitrary numbers of sections, where the symbols for each
6592 section must be relocated relative to that section's landing place in the
6593 target's address space. This work was needed to support ELF with embedded
6594 stabs used by Solaris-2.0.
6596 * Bug fixes (of course!)
6598 There have been loads of fixes for the following things:
6599 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6600 i960, stabs, DOS(GO32), procfs, etc...
6602 See the ChangeLog for details.
6604 *** Changes in GDB-4.5:
6606 * New machines supported (host and target)
6608 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6610 SGI Irix-4.x mips-sgi-irix4 or iris4
6612 * New malloc package
6614 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6615 Mmalloc is capable of handling mutiple heaps of memory. It is also
6616 capable of saving a heap to a file, and then mapping it back in later.
6617 This can be used to greatly speedup the startup of GDB by using a
6618 pre-parsed symbol table which lives in a mmalloc managed heap. For
6619 more details, please read mmalloc/mmalloc.texi.
6623 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6624 'help info proc' for details.
6626 * MIPS ecoff symbol table format
6628 The code that reads MIPS symbol table format is now supported on all hosts.
6629 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6632 * File name changes for MS-DOS
6634 Many files in the config directories have been renamed to make it easier to
6635 support GDB on MS-DOSe systems (which have very restrictive file name
6636 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6637 environment) is close to working but has some remaining problems. Note
6638 that debugging of DOS programs is not supported, due to limitations
6639 in the ``operating system'', but it can be used to host cross-debugging.
6641 * Cross byte order fixes
6643 Many fixes have been made to support cross debugging of Sparc and MIPS
6644 targets from hosts whose byte order differs.
6646 * New -mapped and -readnow options
6648 If memory-mapped files are available on your system through the 'mmap'
6649 system call, you can use the -mapped option on the `file' or
6650 `symbol-file' commands to cause GDB to write the symbols from your
6651 program into a reusable file. If the program you are debugging is
6652 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6653 Future GDB debugging sessions will notice the presence of this file,
6654 and will quickly map in symbol information from it, rather than reading
6655 the symbol table from the executable program. Using the '-mapped'
6656 option in a GDB `file' or `symbol-file' command has the same effect as
6657 starting GDB with the '-mapped' command-line option.
6659 You can cause GDB to read the entire symbol table immediately by using
6660 the '-readnow' option with any of the commands that load symbol table
6661 information (or on the GDB command line). This makes the command
6662 slower, but makes future operations faster.
6664 The -mapped and -readnow options are typically combined in order to
6665 build a `fred.syms' file that contains complete symbol information.
6666 A simple GDB invocation to do nothing but build a `.syms' file for future
6669 gdb -batch -nx -mapped -readnow programname
6671 The `.syms' file is specific to the host machine on which GDB is run.
6672 It holds an exact image of GDB's internal symbol table. It cannot be
6673 shared across multiple host platforms.
6675 * longjmp() handling
6677 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6678 siglongjmp() without losing control. This feature has not yet been ported to
6679 all systems. It currently works on many 386 platforms, all MIPS-based
6680 platforms (SGI, DECstation, etc), and Sun3/4.
6684 Preliminary work has been put in to support the new Solaris OS from Sun. At
6685 this time, it can control and debug processes, but it is not capable of
6690 As always, many many bug fixes. The major areas were with g++, and mipsread.
6691 People using the MIPS-based platforms should experience fewer mysterious
6692 crashes and trashed symbol tables.
6694 *** Changes in GDB-4.4:
6696 * New machines supported (host and target)
6698 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6700 BSD Reno on Vax vax-dec-bsd
6701 Ultrix on Vax vax-dec-ultrix
6703 * New machines supported (target)
6705 AMD 29000 embedded, using EBMON a29k-none-none
6709 GDB continues to improve its handling of C++. `References' work better.
6710 The demangler has also been improved, and now deals with symbols mangled as
6711 per the Annotated C++ Reference Guide.
6713 GDB also now handles `stabs' symbol information embedded in MIPS
6714 `ecoff' symbol tables. Since the ecoff format was not easily
6715 extensible to handle new languages such as C++, this appeared to be a
6716 good way to put C++ debugging info into MIPS binaries. This option
6717 will be supported in the GNU C compiler, version 2, when it is
6720 * New features for SVR4
6722 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6723 shared libraries. Debugging dynamically linked programs should present
6724 only minor differences from debugging statically linked programs.
6726 The `info proc' command will print out information about any process
6727 on an SVR4 system (including the one you are debugging). At the moment,
6728 it prints the address mappings of the process.
6730 If you bring up GDB on another SVR4 system, please send mail to
6731 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6733 * Better dynamic linking support in SunOS
6735 Reading symbols from shared libraries which contain debugging symbols
6736 now works properly. However, there remain issues such as automatic
6737 skipping of `transfer vector' code during function calls, which
6738 make it harder to debug code in a shared library, than to debug the
6739 same code linked statically.
6743 GDB is now using the latest `getopt' routines from the FSF. This
6744 version accepts the -- prefix for options with long names. GDB will
6745 continue to accept the old forms (-option and +option) as well.
6746 Various single letter abbreviations for options have been explicity
6747 added to the option table so that they won't get overshadowed in the
6748 future by other options that begin with the same letter.
6752 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6753 Many assorted bugs have been handled. Many more remain to be handled.
6754 See the various ChangeLog files (primarily in gdb and bfd) for details.
6757 *** Changes in GDB-4.3:
6759 * New machines supported (host and target)
6761 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6762 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6763 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6765 * Almost SCO Unix support
6767 We had hoped to support:
6768 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6769 (except for core file support), but we discovered very late in the release
6770 that it has problems with process groups that render gdb unusable. Sorry
6771 about that. I encourage people to fix it and post the fixes.
6773 * Preliminary ELF and DWARF support
6775 GDB can read ELF object files on System V Release 4, and can handle
6776 debugging records for C, in DWARF format, in ELF files. This support
6777 is preliminary. If you bring up GDB on another SVR4 system, please
6778 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6783 GDB now uses the latest `readline' library. One user-visible change
6784 is that two tabs will list possible command completions, which previously
6785 required typing M-? (meta-question mark, or ESC ?).
6789 The `stepi' bug that many of you noticed has been squashed.
6790 Many bugs in C++ have been handled. Many more remain to be handled.
6791 See the various ChangeLog files (primarily in gdb and bfd) for details.
6793 * State of the MIPS world (in case you wondered):
6795 GDB can understand the symbol tables emitted by the compilers
6796 supplied by most vendors of MIPS-based machines, including DEC. These
6797 symbol tables are in a format that essentially nobody else uses.
6799 Some versions of gcc come with an assembler post-processor called
6800 mips-tfile. This program is required if you want to do source-level
6801 debugging of gcc-compiled programs. I believe FSF does not ship
6802 mips-tfile with gcc version 1, but it will eventually come with gcc
6805 Debugging of g++ output remains a problem. g++ version 1.xx does not
6806 really support it at all. (If you're lucky, you should be able to get
6807 line numbers and stack traces to work, but no parameters or local
6808 variables.) With some work it should be possible to improve the
6811 When gcc version 2 is released, you will have somewhat better luck.
6812 However, even then you will get confusing results for inheritance and
6815 We will eventually provide full debugging of g++ output on
6816 DECstations. This will probably involve some kind of stabs-in-ecoff
6817 encapulation, but the details have not been worked out yet.
6820 *** Changes in GDB-4.2:
6822 * Improved configuration
6824 Only one copy of `configure' exists now, and it is not self-modifying.
6825 Porting BFD is simpler.
6829 The `step' and `next' commands now only stop at the first instruction
6830 of a source line. This prevents the multiple stops that used to occur
6831 in switch statements, for-loops, etc. `Step' continues to stop if a
6832 function that has debugging information is called within the line.
6836 Lots of small bugs fixed. More remain.
6838 * New host supported (not target)
6840 Intel 386 PC clone running Mach i386-none-mach
6843 *** Changes in GDB-4.1:
6845 * Multiple source language support
6847 GDB now has internal scaffolding to handle several source languages.
6848 It determines the type of each source file from its filename extension,
6849 and will switch expression parsing and number formatting to match the
6850 language of the function in the currently selected stack frame.
6851 You can also specifically set the language to be used, with
6852 `set language c' or `set language modula-2'.
6856 GDB now has preliminary support for the GNU Modula-2 compiler,
6857 currently under development at the State University of New York at
6858 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6859 continue through the fall of 1991 and into 1992.
6861 Other Modula-2 compilers are currently not supported, and attempting to
6862 debug programs compiled with them will likely result in an error as the
6863 symbol table is read. Feel free to work on it, though!
6865 There are hooks in GDB for strict type checking and range checking,
6866 in the `Modula-2 philosophy', but they do not currently work.
6870 GDB can now write to executable and core files (e.g. patch
6871 a variable's value). You must turn this switch on, specify
6872 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6873 by assigning a new value to a variable. Modifications take
6876 * Automatic SunOS shared library reading
6878 When you run your program, GDB automatically determines where its
6879 shared libraries (if any) have been loaded, and reads their symbols.
6880 The `share' command is no longer needed. This also works when
6881 examining core files.
6885 You can specify the number of lines that the `list' command shows.
6888 * New machines supported (host and target)
6890 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6891 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6892 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6894 * New hosts supported (not targets)
6896 IBM RT/PC: romp-ibm-aix or rtpc
6898 * New targets supported (not hosts)
6900 AMD 29000 embedded with COFF a29k-none-coff
6901 AMD 29000 embedded with a.out a29k-none-aout
6902 Ultracomputer remote kernel debug a29k-nyu-kern
6904 * New remote interfaces
6910 *** Changes in GDB-4.0:
6914 Wide output is wrapped at good places to make the output more readable.
6916 Gdb now supports cross-debugging from a host machine of one type to a
6917 target machine of another type. Communication with the target system
6918 is over serial lines. The ``target'' command handles connecting to the
6919 remote system; the ``load'' command will download a program into the
6920 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6921 also supports debugging of realtime processes running under VxWorks,
6922 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6923 stub on the target system.
6925 New CPUs supported include the AMD 29000 and Intel 960.
6927 GDB now reads object files and symbol tables via a ``binary file''
6928 library, which allows a single copy of GDB to debug programs of multiple
6929 object file types such as a.out and coff.
6931 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6932 refcard.dvi and refcard.ps are available to format it).
6935 * Control-Variable user interface simplified
6937 All variables that control the operation of the debugger can be set
6938 by the ``set'' command, and displayed by the ``show'' command.
6940 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6941 ``Show prompt'' produces the response:
6942 Gdb's prompt is new-gdb=>.
6944 What follows are the NEW set commands. The command ``help set'' will
6945 print a complete list of old and new set commands. ``help set FOO''
6946 will give a longer description of the variable FOO. ``show'' will show
6947 all of the variable descriptions and their current settings.
6949 confirm on/off: Enables warning questions for operations that are
6950 hard to recover from, e.g. rerunning the program while
6951 it is already running. Default is ON.
6953 editing on/off: Enables EMACS style command line editing
6954 of input. Previous lines can be recalled with
6955 control-P, the current line can be edited with control-B,
6956 you can search for commands with control-R, etc.
6959 history filename NAME: NAME is where the gdb command history
6960 will be stored. The default is .gdb_history,
6961 or the value of the environment variable
6964 history size N: The size, in commands, of the command history. The
6965 default is 256, or the value of the environment variable
6968 history save on/off: If this value is set to ON, the history file will
6969 be saved after exiting gdb. If set to OFF, the
6970 file will not be saved. The default is OFF.
6972 history expansion on/off: If this value is set to ON, then csh-like
6973 history expansion will be performed on
6974 command line input. The default is OFF.
6976 radix N: Sets the default radix for input and output. It can be set
6977 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6978 in the current radix, so "set radix 10" is always a no-op.
6980 height N: This integer value is the number of lines on a page. Default
6981 is 24, the current `stty rows'' setting, or the ``li#''
6982 setting from the termcap entry matching the environment
6985 width N: This integer value is the number of characters on a line.
6986 Default is 80, the current `stty cols'' setting, or the ``co#''
6987 setting from the termcap entry matching the environment
6990 Note: ``set screensize'' is obsolete. Use ``set height'' and
6991 ``set width'' instead.
6993 print address on/off: Print memory addresses in various command displays,
6994 such as stack traces and structure values. Gdb looks
6995 more ``symbolic'' if you turn this off; it looks more
6996 ``machine level'' with it on. Default is ON.
6998 print array on/off: Prettyprint arrays. New convenient format! Default
7001 print demangle on/off: Print C++ symbols in "source" form if on,
7004 print asm-demangle on/off: Same, for assembler level printouts
7007 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7010 * Support for Epoch Environment.
7012 The epoch environment is a version of Emacs v18 with windowing. One
7013 new command, ``inspect'', is identical to ``print'', except that if you
7014 are running in the epoch environment, the value is printed in its own
7018 * Support for Shared Libraries
7020 GDB can now debug programs and core files that use SunOS shared libraries.
7021 Symbols from a shared library cannot be referenced
7022 before the shared library has been linked with the program (this
7023 happens after you type ``run'' and before the function main() is entered).
7024 At any time after this linking (including when examining core files
7025 from dynamically linked programs), gdb reads the symbols from each
7026 shared library when you type the ``sharedlibrary'' command.
7027 It can be abbreviated ``share''.
7029 sharedlibrary REGEXP: Load shared object library symbols for files
7030 matching a unix regular expression. No argument
7031 indicates to load symbols for all shared libraries.
7033 info sharedlibrary: Status of loaded shared libraries.
7038 A watchpoint stops execution of a program whenever the value of an
7039 expression changes. Checking for this slows down execution
7040 tremendously whenever you are in the scope of the expression, but is
7041 quite useful for catching tough ``bit-spreader'' or pointer misuse
7042 problems. Some machines such as the 386 have hardware for doing this
7043 more quickly, and future versions of gdb will use this hardware.
7045 watch EXP: Set a watchpoint (breakpoint) for an expression.
7047 info watchpoints: Information about your watchpoints.
7049 delete N: Deletes watchpoint number N (same as breakpoints).
7050 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7051 enable N: Re-enables watchpoint number N (same as breakpoints).
7054 * C++ multiple inheritance
7056 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7059 * C++ exception handling
7061 Gdb now supports limited C++ exception handling. Besides the existing
7062 ability to breakpoint on an exception handler, gdb can breakpoint on
7063 the raising of an exception (before the stack is peeled back to the
7066 catch FOO: If there is a FOO exception handler in the dynamic scope,
7067 set a breakpoint to catch exceptions which may be raised there.
7068 Multiple exceptions (``catch foo bar baz'') may be caught.
7070 info catch: Lists all exceptions which may be caught in the
7071 current stack frame.
7074 * Minor command changes
7076 The command ``call func (arg, arg, ...)'' now acts like the print
7077 command, except it does not print or save a value if the function's result
7078 is void. This is similar to dbx usage.
7080 The ``up'' and ``down'' commands now always print the frame they end up
7081 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7082 frames without printing.
7084 * New directory command
7086 'dir' now adds directories to the FRONT of the source search path.
7087 The path starts off empty. Source files that contain debug information
7088 about the directory in which they were compiled can be found even
7089 with an empty path; Sun CC and GCC include this information. If GDB can't
7090 find your source file in the current directory, type "dir .".
7092 * Configuring GDB for compilation
7094 For normal use, type ``./configure host''. See README or gdb.texinfo
7097 GDB now handles cross debugging. If you are remotely debugging between
7098 two different machines, type ``./configure host -target=targ''.
7099 Host is the machine where GDB will run; targ is the machine
7100 where the program that you are debugging will run.