1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * GDB now uses the GNU MPFR library, if available, to emulate target
7 floating-point arithmetic during expression evaluation when the target
8 uses different floating-point formats than the host. At least version
9 3.1 of GNU MPFR is required.
11 * GDB now supports access to the guarded-storage-control registers and the
12 software-based guarded-storage broadcast control registers on IBM z14.
14 * On Unix systems, GDB now supports transmitting environment variables
15 that are to be set or unset to GDBserver. These variables will
16 affect the environment to be passed to the remote inferior.
18 To inform GDB of environment variables that are to be transmitted to
19 GDBserver, use the "set environment" command. Only user set
20 environment variables are sent to GDBserver.
22 To inform GDB of environment variables that are to be unset before
23 the remote inferior is started by the GDBserver, use the "unset
26 * Completion improvements
28 ** GDB can now complete function parameters in linespecs and
29 explicit locations without quoting. When setting breakpoints,
30 quoting around functions names to help with TAB-completion is
31 generally no longer necessary. For example, this now completes
34 (gdb) b function(in[TAB]
37 Related, GDB is no longer confused with completing functions in
38 C++ anonymous namespaces:
41 (gdb) b (anonymous namespace)::[TAB][TAB]
42 (anonymous namespace)::a_function()
43 (anonymous namespace)::b_function()
45 ** GDB now has much improved linespec and explicit locations TAB
46 completion support, that better understands what you're
47 completing and offers better suggestions. For example, GDB no
48 longer offers data symbols as possible completions when you're
51 ** GDB now TAB-completes label symbol names.
53 ** The "complete" command now mimics TAB completion accurately.
55 * Breakpoints on C++ functions are now set on all scopes by default
57 By default, breakpoints on functions/methods are now interpreted as
58 specifying all functions with the given name ignoring missing
59 leading scopes (namespaces and classes).
61 For example, assuming a C++ program with symbols named:
66 both commands "break func()" and "break B::func()" set a breakpoint
69 You can use the new flag "-qualified" to override this. This makes
70 GDB interpret the specified function name as a complete
71 fully-qualified name instead. For example, using the same C++
72 program, the "break -q B::func" command sets a breakpoint on
77 ** New events gdb.new_inferior, gdb.inferior_deleted, and
78 gdb.new_thread are emitted. See the manual for further
81 ** A new command, "rbreak" has been added to the Python API. This
82 command allows the setting of a large number of breakpoints via a
83 regex pattern in Python. See the manual for further details.
85 * New features in the GDB remote stub, GDBserver
87 ** GDBserver is now able to start inferior processes with a
88 specified initial working directory.
90 The user can set the desired working directory to be used from
91 GDB using the new "set cwd" command.
93 ** New "--selftest" command line option runs some GDBserver self
94 tests. These self tests are disabled in releases.
96 ** On Unix systems, GDBserver now does globbing expansion and variable
97 substitution in inferior command line arguments.
99 This is done by starting inferiors using a shell, like GDB does.
100 See "set startup-with-shell" in the user manual for how to disable
101 this from GDB when using "target extended-remote". When using
102 "target remote", you can disable the startup with shell by using the
103 new "--no-startup-with-shell" GDBserver command line option.
105 ** On Unix systems, GDBserver now supports receiving environment
106 variables that are to be set or unset from GDB. These variables
107 will affect the environment to be passed to the inferior.
109 * When catching an Ada exception raised with a message, GDB now prints
110 the message in the catchpoint hit notification. In GDB/MI mode, that
111 information is provided as an extra field named "exception-message"
112 in the *stopped notification.
116 QEnvironmentHexEncoded
117 Inform GDBserver of an environment variable that is to be passed to
118 the inferior when starting it.
121 Inform GDBserver of an environment variable that is to be unset
122 before starting the remote inferior.
125 Inform GDBserver that the environment should be reset (i.e.,
126 user-set environment variables should be unset).
129 Indicates whether the inferior must be started with a shell or not.
132 Tell GDBserver that the inferior to be started should use a specific
135 * The "maintenance print c-tdesc" command now takes an optional
136 argument which is the file name of XML target description.
138 * The "maintenance selftest" command now takes an optional argument to
139 filter the tests to be run.
141 * The "enable", and "disable" commands now accept a range of
142 breakpoint locations, e.g. "enable 1.3-5".
147 Set and show the current working directory for the inferior.
150 Set and show compilation command used for compiling and injecting code
151 with the 'compile' commands.
153 set debug separate-debug-file
154 show debug separate-debug-file
155 Control the display of debug output about separate debug file search.
158 List the registered selftests.
161 Start the debugged program stopping at the first instruction.
163 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
166 * Safer/improved support for debugging with no debug info
168 GDB no longer assumes functions with no debug information return
171 This means that GDB now refuses to call such functions unless you
172 tell it the function's type, by either casting the call to the
173 declared return type, or by casting the function to a function
174 pointer of the right type, and calling that:
176 (gdb) p getenv ("PATH")
177 'getenv' has unknown return type; cast the call to its declared return type
178 (gdb) p (char *) getenv ("PATH")
179 $1 = 0x7fffffffe "/usr/local/bin:/"...
180 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
181 $2 = 0x7fffffffe "/usr/local/bin:/"...
183 Similarly, GDB no longer assumes that global variables with no debug
184 info have type 'int', and refuses to print the variable's value
185 unless you tell it the variable's type:
188 'var' has unknown type; cast it to its declared type
192 * New native configurations
194 FreeBSD/aarch64 aarch64*-*-freebsd*
195 FreeBSD/arm arm*-*-freebsd*
199 FreeBSD/aarch64 aarch64*-*-freebsd*
200 FreeBSD/arm arm*-*-freebsd*
202 * Removed targets and native configurations
204 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
206 *** Changes in GDB 8.0
208 * GDB now supports access to the PKU register on GNU/Linux. The register is
209 added by the Memory Protection Keys for Userspace feature which will be
210 available in future Intel CPUs.
212 * GDB now supports C++11 rvalue references.
216 ** New functions to start, stop and access a running btrace recording.
217 ** Rvalue references are now supported in gdb.Type.
219 * GDB now supports recording and replaying rdrand and rdseed Intel 64
222 * Building GDB and GDBserver now requires a C++11 compiler.
224 For example, GCC 4.8 or later.
226 It is no longer possible to build GDB or GDBserver with a C
227 compiler. The --disable-build-with-cxx configure option has been
230 * Building GDB and GDBserver now requires GNU make >= 3.81.
232 It is no longer supported to build GDB or GDBserver with another
233 implementation of the make program or an earlier version of GNU make.
235 * Native debugging on MS-Windows supports command-line redirection
237 Command-line arguments used for starting programs on MS-Windows can
238 now include redirection symbols supported by native Windows shells,
239 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
240 as "run", "start", and "set args", as well as the corresponding MI
243 * Support for thread names on MS-Windows.
245 GDB now catches and handles the special exception that programs
246 running on MS-Windows use to assign names to threads in the
249 * Support for Java programs compiled with gcj has been removed.
251 * User commands now accept an unlimited number of arguments.
252 Previously, only up to 10 was accepted.
254 * The "eval" command now expands user-defined command arguments.
256 This makes it easier to process a variable number of arguments:
261 eval "print $arg%d", $i
266 * Target descriptions can now describe registers for sparc32 and sparc64.
268 * GDB now supports DWARF version 5 (debug information format).
269 Its .debug_names index is not yet supported.
271 * New native configurations
273 FreeBSD/mips mips*-*-freebsd
277 Synopsys ARC arc*-*-elf32
278 FreeBSD/mips mips*-*-freebsd
280 * Removed targets and native configurations
282 Alpha running FreeBSD alpha*-*-freebsd*
283 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
288 Erases all the flash memory regions reported by the target.
290 maint print arc arc-instruction address
291 Print internal disassembler information about instruction at a given address.
295 set disassembler-options
296 show disassembler-options
297 Controls the passing of target specific information to the disassembler.
298 If it is necessary to specify more than one disassembler option then
299 multiple options can be placed together into a comma separated list.
300 The default value is the empty string. Currently, the only supported
301 targets are ARM, PowerPC and S/390.
306 Erases all the flash memory regions reported by the target. This is
307 equivalent to the CLI command flash-erase.
309 -file-list-shared-libraries
310 List the shared libraries in the program. This is
311 equivalent to the CLI command "info shared".
313 *** Changes in GDB 7.12
315 * GDB and GDBserver now build with a C++ compiler by default.
317 The --enable-build-with-cxx configure option is now enabled by
318 default. One must now explicitly configure with
319 --disable-build-with-cxx in order to build with a C compiler. This
320 option will be removed in a future release.
322 * GDBserver now supports recording btrace without maintaining an active
325 * GDB now supports a negative repeat count in the 'x' command to examine
326 memory backward from the given address. For example:
329 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
330 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
331 (gdb) x/-5i 0x0000000000400580
332 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
333 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
334 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
335 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
336 0x40057b <main(int, char**)+25>:
337 callq 0x400536 <Func1(int, char const*)>
339 * Fortran: Support structures with fields of dynamic types and
340 arrays of dynamic types.
342 * The symbol dumping maintenance commands have new syntax.
343 maint print symbols [-pc address] [--] [filename]
344 maint print symbols [-objfile objfile] [-source source] [--] [filename]
345 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
346 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
347 maint print msymbols [-objfile objfile] [--] [filename]
349 * GDB now supports multibit bitfields and enums in target register
352 * New Python-based convenience function $_as_string(val), which returns
353 the textual representation of a value. This function is especially
354 useful to obtain the text label of an enum value.
356 * Intel MPX bound violation handling.
358 Segmentation faults caused by a Intel MPX boundary violation
359 now display the kind of violation (upper or lower), the memory
360 address accessed and the memory bounds, along with the usual
361 signal received and code location.
365 Program received signal SIGSEGV, Segmentation fault
366 Upper bound violation while accessing address 0x7fffffffc3b3
367 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
368 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
370 * Rust language support.
371 GDB now supports debugging programs written in the Rust programming
372 language. See https://www.rust-lang.org/ for more information about
375 * Support for running interpreters on specified input/output devices
377 GDB now supports a new mechanism that allows frontends to provide
378 fully featured GDB console views, as a better alternative to
379 building such views on top of the "-interpreter-exec console"
380 command. See the new "new-ui" command below. With that command,
381 frontends can now start GDB in the traditional command-line mode
382 running in an embedded terminal emulator widget, and create a
383 separate MI interpreter running on a specified i/o device. In this
384 way, GDB handles line editing, history, tab completion, etc. in the
385 console all by itself, and the GUI uses the separate MI interpreter
386 for its own control and synchronization, invisible to the command
389 * The "catch syscall" command catches groups of related syscalls.
391 The "catch syscall" command now supports catching a group of related
392 syscalls using the 'group:' or 'g:' prefix.
397 skip -gfile file-glob-pattern
398 skip -function function
399 skip -rfunction regular-expression
400 A generalized form of the skip command, with new support for
401 glob-style file names and regular expressions for function names.
402 Additionally, a file spec and a function spec may now be combined.
404 maint info line-table REGEXP
405 Display the contents of GDB's internal line table data struture.
408 Run any GDB unit tests that were compiled in.
411 Start a new user interface instance running INTERP as interpreter,
412 using the TTY file for input/output.
416 ** gdb.Breakpoint objects have a new attribute "pending", which
417 indicates whether the breakpoint is pending.
418 ** Three new breakpoint-related events have been added:
419 gdb.breakpoint_created, gdb.breakpoint_modified, and
420 gdb.breakpoint_deleted.
423 Signal ("set") the given MS-Windows event object. This is used in
424 conjunction with the Windows JIT debugging (AeDebug) support, where
425 the OS suspends a crashing process until a debugger can attach to
426 it. Resuming the crashing process, in order to debug it, is done by
429 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
430 was added in GDBserver, including JIT compiling fast tracepoint's
431 conditional expression bytecode into native code.
433 * Support for various remote target protocols and ROM monitors has
436 target m32rsdi Remote M32R debugging over SDI
437 target mips MIPS remote debugging protocol
438 target pmon PMON ROM monitor
439 target ddb NEC's DDB variant of PMON for Vr4300
440 target rockhopper NEC RockHopper variant of PMON
441 target lsi LSI variant of PMO
443 * Support for tracepoints and fast tracepoints on powerpc-linux,
444 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
445 including JIT compiling fast tracepoint's conditional expression
446 bytecode into native code.
448 * MI async record =record-started now includes the method and format used for
449 recording. For example:
451 =record-started,thread-group="i1",method="btrace",format="bts"
453 * MI async record =thread-selected now includes the frame field. For example:
455 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
459 Andes NDS32 nds32*-*-elf
461 *** Changes in GDB 7.11
463 * GDB now supports debugging kernel-based threads on FreeBSD.
465 * Per-inferior thread numbers
467 Thread numbers are now per inferior instead of global. If you're
468 debugging multiple inferiors, GDB displays thread IDs using a
469 qualified INF_NUM.THR_NUM form. For example:
473 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
474 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
475 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
476 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
478 As consequence, thread numbers as visible in the $_thread
479 convenience variable and in Python's InferiorThread.num attribute
480 are no longer unique between inferiors.
482 GDB now maintains a second thread ID per thread, referred to as the
483 global thread ID, which is the new equivalent of thread numbers in
484 previous releases. See also $_gthread below.
486 For backwards compatibility, MI's thread IDs always refer to global
489 * Commands that accept thread IDs now accept the qualified
490 INF_NUM.THR_NUM form as well. For example:
493 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
496 * In commands that accept a list of thread IDs, you can now refer to
497 all threads of an inferior using a star wildcard. GDB accepts
498 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
499 refer to all threads of the current inferior. For example, "info
502 * You can use "info threads -gid" to display the global thread ID of
505 * The new convenience variable $_gthread holds the global number of
508 * The new convenience variable $_inferior holds the number of the
511 * GDB now displays the ID and name of the thread that hit a breakpoint
512 or received a signal, if your program is multi-threaded. For
515 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
516 Thread 1 "main" received signal SIGINT, Interrupt.
518 * Record btrace now supports non-stop mode.
520 * Support for tracepoints on aarch64-linux was added in GDBserver.
522 * The 'record instruction-history' command now indicates speculative execution
523 when using the Intel Processor Trace recording format.
525 * GDB now allows users to specify explicit locations, bypassing
526 the linespec parser. This feature is also available to GDB/MI
529 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
530 GDB now is able to debug both AArch64 applications and ARM applications
533 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
534 including JIT compiling fast tracepoint's conditional expression bytecode
537 * GDB now supports displaced stepping on AArch64 GNU/Linux.
539 * "info threads", "info inferiors", "info display", "info checkpoints"
540 and "maint info program-spaces" now list the corresponding items in
541 ascending ID order, for consistency with all other "info" commands.
543 * In Ada, the overloads selection menu has been enhanced to display the
544 parameter types and the return types for the matching overloaded subprograms.
548 maint set target-non-stop (on|off|auto)
549 maint show target-non-stop
550 Control whether GDB targets always operate in non-stop mode even if
551 "set non-stop" is "off". The default is "auto", meaning non-stop
552 mode is enabled if supported by the target.
554 maint set bfd-sharing
555 maint show bfd-sharing
556 Control the reuse of bfd objects.
560 Control display of debugging info regarding bfd caching.
564 Control display of debugging info regarding FreeBSD threads.
566 set remote multiprocess-extensions-packet
567 show remote multiprocess-extensions-packet
568 Set/show the use of the remote protocol multiprocess extensions.
570 set remote thread-events
571 show remote thread-events
572 Set/show the use of thread create/exit events.
574 set ada print-signatures on|off
575 show ada print-signatures"
576 Control whether parameter types and return types are displayed in overloads
577 selection menus. It is activaled (@code{on}) by default.
581 Controls the maximum size of memory, in bytes, that GDB will
582 allocate for value contents. Prevents incorrect programs from
583 causing GDB to allocate overly large buffers. Default is 64k.
585 * The "disassemble" command accepts a new modifier: /s.
586 It prints mixed source+disassembly like /m with two differences:
587 - disassembled instructions are now printed in program order, and
588 - and source for all relevant files is now printed.
589 The "/m" option is now considered deprecated: its "source-centric"
590 output hasn't proved useful in practice.
592 * The "record instruction-history" command accepts a new modifier: /s.
593 It behaves exactly like /m and prints mixed source+disassembly.
595 * The "set scheduler-locking" command supports a new mode "replay".
596 It behaves like "off" in record mode and like "on" in replay mode.
598 * Support for various ROM monitors has been removed:
600 target dbug dBUG ROM monitor for Motorola ColdFire
601 target picobug Motorola picobug monitor
602 target dink32 DINK32 ROM monitor for PowerPC
603 target m32r Renesas M32R/D ROM monitor
604 target mon2000 mon2000 ROM monitor
605 target ppcbug PPCBUG ROM monitor for PowerPC
607 * Support for reading/writing memory and extracting values on architectures
608 whose memory is addressable in units of any integral multiple of 8 bits.
613 Indicates that an exec system call was executed.
615 exec-events feature in qSupported
616 The qSupported packet allows GDB to request support for exec
617 events using the new 'gdbfeature' exec-event, and the qSupported
618 response can contain the corresponding 'stubfeature'. Set and
619 show commands can be used to display whether these features are enabled.
622 Equivalent to interrupting with the ^C character, but works in
625 thread created stop reason (T05 create:...)
626 Indicates that the thread was just created and is stopped at entry.
628 thread exit stop reply (w exitcode;tid)
629 Indicates that the thread has terminated.
632 Enables/disables thread create and exit event reporting. For
633 example, this is used in non-stop mode when GDB stops a set of
634 threads and synchronously waits for the their corresponding stop
635 replies. Without exit events, if one of the threads exits, GDB
636 would hang forever not knowing that it should no longer expect a
637 stop for that same thread.
640 Indicates that there are no resumed threads left in the target (all
641 threads are stopped). The remote stub reports support for this stop
642 reply to GDB's qSupported query.
645 Enables/disables catching syscalls from the inferior process.
646 The remote stub reports support for this packet to GDB's qSupported query.
648 syscall_entry stop reason
649 Indicates that a syscall was just called.
651 syscall_return stop reason
652 Indicates that a syscall just returned.
654 * Extended-remote exec events
656 ** GDB now has support for exec events on extended-remote Linux targets.
657 For such targets with Linux kernels 2.5.46 and later, this enables
658 follow-exec-mode and exec catchpoints.
660 set remote exec-event-feature-packet
661 show remote exec-event-feature-packet
662 Set/show the use of the remote exec event feature.
664 * Thread names in remote protocol
666 The reply to qXfer:threads:read may now include a name attribute for each
669 * Target remote mode fork and exec events
671 ** GDB now has support for fork and exec events on target remote mode
672 Linux targets. For such targets with Linux kernels 2.5.46 and later,
673 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
674 fork and exec catchpoints.
676 * Remote syscall events
678 ** GDB now has support for catch syscall on remote Linux targets,
679 currently enabled on x86/x86_64 architectures.
681 set remote catch-syscall-packet
682 show remote catch-syscall-packet
683 Set/show the use of the remote catch syscall feature.
687 ** The -var-set-format command now accepts the zero-hexadecimal
688 format. It outputs data in hexadecimal format with zero-padding on the
693 ** gdb.InferiorThread objects have a new attribute "global_num",
694 which refers to the thread's global thread ID. The existing
695 "num" attribute now refers to the thread's per-inferior number.
696 See "Per-inferior thread numbers" above.
697 ** gdb.InferiorThread objects have a new attribute "inferior", which
698 is the Inferior object the thread belongs to.
700 *** Changes in GDB 7.10
702 * Support for process record-replay and reverse debugging on aarch64*-linux*
703 targets has been added. GDB now supports recording of A64 instruction set
704 including advance SIMD instructions.
706 * Support for Sun's version of the "stabs" debug file format has been removed.
708 * GDB now honors the content of the file /proc/PID/coredump_filter
709 (PID is the process ID) on GNU/Linux systems. This file can be used
710 to specify the types of memory mappings that will be included in a
711 corefile. For more information, please refer to the manual page of
712 "core(5)". GDB also has a new command: "set use-coredump-filter
713 on|off". It allows to set whether GDB will read the content of the
714 /proc/PID/coredump_filter file when generating a corefile.
716 * The "info os" command on GNU/Linux can now display information on
718 "info os cpus" Listing of all cpus/cores on the system
720 * GDB has two new commands: "set serial parity odd|even|none" and
721 "show serial parity". These allows to set or show parity for the
724 * The "info source" command now displays the producer string if it was
725 present in the debug info. This typically includes the compiler version
726 and may include things like its command line arguments.
728 * The "info dll", an alias of the "info sharedlibrary" command,
729 is now available on all platforms.
731 * Directory names supplied to the "set sysroot" commands may be
732 prefixed with "target:" to tell GDB to access shared libraries from
733 the target system, be it local or remote. This replaces the prefix
734 "remote:". The default sysroot has been changed from "" to
735 "target:". "remote:" is automatically converted to "target:" for
736 backward compatibility.
738 * The system root specified by "set sysroot" will be prepended to the
739 filename of the main executable (if reported to GDB as absolute by
740 the operating system) when starting processes remotely, and when
741 attaching to already-running local or remote processes.
743 * GDB now supports automatic location and retrieval of executable
744 files from remote targets. Remote debugging can now be initiated
745 using only a "target remote" or "target extended-remote" command
746 (no "set sysroot" or "file" commands are required). See "New remote
749 * The "dump" command now supports verilog hex format.
751 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
753 * On GNU/Linux, GDB and gdbserver are now able to access executable
754 and shared library files without a "set sysroot" command when
755 attaching to processes running in different mount namespaces from
756 the debugger. This makes it possible to attach to processes in
757 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
758 See "New remote packets" below.
760 * The "tui reg" command now provides completion for all of the
761 available register groups, including target specific groups.
763 * The HISTSIZE environment variable is no longer read when determining
764 the size of GDB's command history. GDB now instead reads the dedicated
765 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
766 disables truncation of command history. Non-numeric values of GDBHISTSIZE
771 ** Memory ports can now be unbuffered.
775 ** gdb.Objfile objects have a new attribute "username",
776 which is the name of the objfile as specified by the user,
777 without, for example, resolving symlinks.
778 ** You can now write frame unwinders in Python.
779 ** gdb.Type objects have a new method "optimized_out",
780 returning optimized out gdb.Value instance of this type.
781 ** gdb.Value objects have new methods "reference_value" and
782 "const_value" which return a reference to the value and a
783 "const" version of the value respectively.
787 maint print symbol-cache
788 Print the contents of the symbol cache.
790 maint print symbol-cache-statistics
791 Print statistics of symbol cache usage.
793 maint flush-symbol-cache
794 Flush the contents of the symbol cache.
798 Start branch trace recording using Branch Trace Store (BTS) format.
801 Evaluate expression by using the compiler and print result.
805 Explicit commands for enabling and disabling tui mode.
808 set mpx bound on i386 and amd64
809 Support for bound table investigation on Intel MPX enabled applications.
813 Start branch trace recording using Intel Processor Trace format.
816 Print information about branch tracing internals.
818 maint btrace packet-history
819 Print the raw branch tracing data.
821 maint btrace clear-packet-history
822 Discard the stored raw branch tracing data.
825 Discard all branch tracing data. It will be fetched and processed
826 anew by the next "record" command.
831 Renamed from "set debug dwarf2-die".
833 Renamed from "show debug dwarf2-die".
836 Renamed from "set debug dwarf2-read".
837 show debug dwarf-read
838 Renamed from "show debug dwarf2-read".
840 maint set dwarf always-disassemble
841 Renamed from "maint set dwarf2 always-disassemble".
842 maint show dwarf always-disassemble
843 Renamed from "maint show dwarf2 always-disassemble".
845 maint set dwarf max-cache-age
846 Renamed from "maint set dwarf2 max-cache-age".
847 maint show dwarf max-cache-age
848 Renamed from "maint show dwarf2 max-cache-age".
851 show debug dwarf-line
852 Control display of debugging info regarding DWARF line processing.
856 Set the maximum number of candidates to be considered during
857 completion. The default value is 200. This limit allows GDB
858 to avoid generating large completion lists, the computation of
859 which can cause the debugger to become temporarily unresponsive.
861 set history remove-duplicates
862 show history remove-duplicates
863 Control the removal of duplicate history entries.
865 maint set symbol-cache-size
866 maint show symbol-cache-size
867 Control the size of the symbol cache.
869 set|show record btrace bts buffer-size
870 Set and show the size of the ring buffer used for branch tracing in
872 The obtained size may differ from the requested size. Use "info
873 record" to see the obtained buffer size.
875 set debug linux-namespaces
876 show debug linux-namespaces
877 Control display of debugging info regarding Linux namespaces.
879 set|show record btrace pt buffer-size
880 Set and show the size of the ring buffer used for branch tracing in
881 Intel Processor Trace format.
882 The obtained size may differ from the requested size. Use "info
883 record" to see the obtained buffer size.
885 maint set|show btrace pt skip-pad
886 Set and show whether PAD packets are skipped when computing the
889 * The command 'thread apply all' can now support new option '-ascending'
890 to call its specified command for all threads in ascending order.
892 * Python/Guile scripting
894 ** GDB now supports auto-loading of Python/Guile scripts contained in the
895 special section named `.debug_gdb_scripts'.
899 qXfer:btrace-conf:read
900 Return the branch trace configuration for the current thread.
902 Qbtrace-conf:bts:size
903 Set the requested ring buffer size for branch tracing in BTS format.
906 Enable Intel Procesor Trace-based branch tracing for the current
907 process. The remote stub reports support for this packet to GDB's
911 Set the requested ring buffer size for branch tracing in Intel Processor
915 Indicates a memory breakpoint instruction was executed, irrespective
916 of whether it was GDB that planted the breakpoint or the breakpoint
917 is hardcoded in the program. This is required for correct non-stop
921 Indicates the target stopped for a hardware breakpoint. This is
922 required for correct non-stop mode operation.
925 Return information about files on the remote system.
928 Return the full absolute name of the file that was executed to
929 create a process running on the remote system.
932 Select the filesystem on which vFile: operations with filename
933 arguments will operate. This is required for GDB to be able to
934 access files on remote targets where the remote stub does not
935 share a common filesystem with the inferior(s).
938 Indicates that a fork system call was executed.
941 Indicates that a vfork system call was executed.
943 vforkdone stop reason
944 Indicates that a vfork child of the specified process has executed
945 an exec or exit, allowing the vfork parent to resume execution.
947 fork-events and vfork-events features in qSupported
948 The qSupported packet allows GDB to request support for fork and
949 vfork events using new 'gdbfeatures' fork-events and vfork-events,
950 and the qSupported response can contain the corresponding
951 'stubfeatures'. Set and show commands can be used to display
952 whether these features are enabled.
954 * Extended-remote fork events
956 ** GDB now has support for fork events on extended-remote Linux
957 targets. For targets with Linux kernels 2.5.60 and later, this
958 enables follow-fork-mode and detach-on-fork for both fork and
959 vfork, as well as fork and vfork catchpoints.
961 * The info record command now shows the recording format and the
962 branch tracing configuration for the current thread when using
963 the btrace record target.
964 For the BTS format, it shows the ring buffer size.
966 * GDB now has support for DTrace USDT (Userland Static Defined
967 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
969 * GDB now supports access to vector registers on S/390 GNU/Linux
972 * Removed command line options
974 -xdb HP-UX XDB compatibility mode.
976 * Removed targets and native configurations
978 HP/PA running HP-UX hppa*-*-hpux*
979 Itanium running HP-UX ia64-*-hpux*
981 * New configure options
984 This configure option allows the user to build GDB with support for
985 Intel Processor Trace (default: auto). This requires libipt.
987 --with-libipt-prefix=PATH
988 Specify the path to the version of libipt that GDB should use.
989 $PATH/include should contain the intel-pt.h header and
990 $PATH/lib should contain the libipt.so library.
992 *** Changes in GDB 7.9.1
996 ** Xmethods can now specify a result type.
998 *** Changes in GDB 7.9
1000 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1004 ** You can now access frame registers from Python scripts.
1005 ** New attribute 'producer' for gdb.Symtab objects.
1006 ** gdb.Objfile objects have a new attribute "progspace",
1007 which is the gdb.Progspace object of the containing program space.
1008 ** gdb.Objfile objects have a new attribute "owner".
1009 ** gdb.Objfile objects have a new attribute "build_id",
1010 which is the build ID generated when the file was built.
1011 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1012 ** A new event "gdb.clear_objfiles" has been added, triggered when
1013 selecting a new file to debug.
1014 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1015 ** New function gdb.lookup_objfile.
1017 New events which are triggered when GDB modifies the state of the
1020 ** gdb.events.inferior_call_pre: Function call is about to be made.
1021 ** gdb.events.inferior_call_post: Function call has just been made.
1022 ** gdb.events.memory_changed: A memory location has been altered.
1023 ** gdb.events.register_changed: A register has been altered.
1025 * New Python-based convenience functions:
1027 ** $_caller_is(name [, number_of_frames])
1028 ** $_caller_matches(regexp [, number_of_frames])
1029 ** $_any_caller_is(name [, number_of_frames])
1030 ** $_any_caller_matches(regexp [, number_of_frames])
1032 * GDB now supports the compilation and injection of source code into
1033 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1034 to compile the source code to object code, and if successful, inject
1035 and execute that code within the current context of the inferior.
1036 Currently the C language is supported. The commands used to
1037 interface with this new feature are:
1039 compile code [-raw|-r] [--] [source code]
1040 compile file [-raw|-r] filename
1044 demangle [-l language] [--] name
1045 Demangle "name" in the specified language, or the current language
1046 if elided. This command is renamed from the "maint demangle" command.
1047 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1048 as "maint demangler-warning".
1050 queue-signal signal-name-or-number
1051 Queue a signal to be delivered to the thread when it is resumed.
1053 add-auto-load-scripts-directory directory
1054 Add entries to the list of directories from which to load auto-loaded
1057 maint print user-registers
1058 List all currently available "user" registers.
1060 compile code [-r|-raw] [--] [source code]
1061 Compile, inject, and execute in the inferior the executable object
1062 code produced by compiling the provided source code.
1064 compile file [-r|-raw] filename
1065 Compile and inject into the inferior the executable object code
1066 produced by compiling the source code stored in the filename
1069 * On resume, GDB now always passes the signal the program had stopped
1070 for to the thread the signal was sent to, even if the user changed
1071 threads before resuming. Previously GDB would often (but not
1072 always) deliver the signal to the thread that happens to be current
1075 * Conversely, the "signal" command now consistently delivers the
1076 requested signal to the current thread. GDB now asks for
1077 confirmation if the program had stopped for a signal and the user
1078 switched threads meanwhile.
1080 * "breakpoint always-inserted" modes "off" and "auto" merged.
1082 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1083 won't remove breakpoints from the target until all threads stop,
1084 even in non-stop mode. The "auto" mode has been removed, and "off"
1085 is now the default mode.
1089 set debug symbol-lookup
1090 show debug symbol-lookup
1091 Control display of debugging info regarding symbol lookup.
1095 ** The -list-thread-groups command outputs an exit-code field for
1096 inferiors that have exited.
1100 MIPS SDE mips*-sde*-elf*
1104 Support for these obsolete configurations has been removed.
1106 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1107 SGI Irix-5.x mips-*-irix5*
1108 SGI Irix-6.x mips-*-irix6*
1109 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1110 VAX running Ultrix vax-*-ultrix*
1112 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1113 and "assf"), have been removed. Use the "sharedlibrary" command, or
1114 its alias "share", instead.
1116 *** Changes in GDB 7.8
1118 * New command line options
1121 This is an alias for the --data-directory option.
1123 * GDB supports printing and modifying of variable length automatic arrays
1124 as specified in ISO C99.
1126 * The ARM simulator now supports instruction level tracing
1127 with or without disassembly.
1131 GDB now has support for scripting using Guile. Whether this is
1132 available is determined at configure time.
1133 Guile version 2.0 or greater is required.
1134 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1136 * New commands (for set/show, see "New options" below)
1140 Invoke CODE by passing it to the Guile interpreter.
1144 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1146 info auto-load guile-scripts [regexp]
1147 Print the list of automatically loaded Guile scripts.
1149 * The source command is now capable of sourcing Guile scripts.
1150 This feature is dependent on the debugger being built with Guile support.
1154 set print symbol-loading (off|brief|full)
1155 show print symbol-loading
1156 Control whether to print informational messages when loading symbol
1157 information for a file. The default is "full", but when debugging
1158 programs with large numbers of shared libraries the amount of output
1159 becomes less useful.
1161 set guile print-stack (none|message|full)
1162 show guile print-stack
1163 Show a stack trace when an error is encountered in a Guile script.
1165 set auto-load guile-scripts (on|off)
1166 show auto-load guile-scripts
1167 Control auto-loading of Guile script files.
1169 maint ada set ignore-descriptive-types (on|off)
1170 maint ada show ignore-descriptive-types
1171 Control whether the debugger should ignore descriptive types in Ada
1172 programs. The default is not to ignore the descriptive types. See
1173 the user manual for more details on descriptive types and the intended
1174 usage of this option.
1176 set auto-connect-native-target
1178 Control whether GDB is allowed to automatically connect to the
1179 native target for the run, attach, etc. commands when not connected
1180 to any target yet. See also "target native" below.
1182 set record btrace replay-memory-access (read-only|read-write)
1183 show record btrace replay-memory-access
1184 Control what memory accesses are allowed during replay.
1186 maint set target-async (on|off)
1187 maint show target-async
1188 This controls whether GDB targets operate in synchronous or
1189 asynchronous mode. Normally the default is asynchronous, if it is
1190 available; but this can be changed to more easily debug problems
1191 occurring only in synchronous mode.
1193 set mi-async (on|off)
1195 Control whether MI asynchronous mode is preferred. This supersedes
1196 "set target-async" of previous GDB versions.
1198 * "set target-async" is deprecated as a CLI option and is now an alias
1199 for "set mi-async" (only puts MI into async mode).
1201 * Background execution commands (e.g., "c&", "s&", etc.) are now
1202 possible ``out of the box'' if the target supports them. Previously
1203 the user would need to explicitly enable the possibility with the
1204 "set target-async on" command.
1206 * New features in the GDB remote stub, GDBserver
1208 ** New option --debug-format=option1[,option2,...] allows one to add
1209 additional text to each output. At present only timestamps
1210 are supported: --debug-format=timestamps.
1211 Timestamps can also be turned on with the
1212 "monitor set debug-format timestamps" command from GDB.
1214 * The 'record instruction-history' command now starts counting instructions
1215 at one. This also affects the instruction ranges reported by the
1216 'record function-call-history' command when given the /i modifier.
1218 * The command 'record function-call-history' supports a new modifier '/c' to
1219 indent the function names based on their call stack depth.
1220 The fields for the '/i' and '/l' modifier have been reordered.
1221 The source line range is now prefixed with 'at'.
1222 The instruction range is now prefixed with 'inst'.
1223 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1224 "record instruction-history" and "list" commands.
1226 * The ranges given as arguments to the 'record function-call-history' and
1227 'record instruction-history' commands are now inclusive.
1229 * The btrace record target now supports the 'record goto' command.
1230 For locations inside the execution trace, the back trace is computed
1231 based on the information stored in the execution trace.
1233 * The btrace record target supports limited reverse execution and replay.
1234 The target does not record data and therefore does not allow reading
1235 memory or registers.
1237 * The "catch syscall" command now works on s390*-linux* targets.
1239 * The "compare-sections" command is no longer specific to target
1240 remote. It now works with all targets.
1242 * All native targets are now consistently called "native".
1243 Consequently, the "target child", "target GNU", "target djgpp",
1244 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1245 commands have been replaced with "target native". The QNX/NTO port
1246 leaves the "procfs" target in place and adds a "native" target for
1247 consistency with other ports. The impact on users should be minimal
1248 as these commands previously either throwed an error, or were
1249 no-ops. The target's name is visible in the output of the following
1250 commands: "help target", "info target", "info files", "maint print
1253 * The "target native" command now connects to the native target. This
1254 can be used to launch native programs even when "set
1255 auto-connect-native-target" is set to off.
1257 * GDB now supports access to Intel MPX registers on GNU/Linux.
1259 * Support for Intel AVX-512 registers on GNU/Linux.
1260 Support displaying and modifying Intel AVX-512 registers
1261 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1263 * New remote packets
1265 qXfer:btrace:read's annex
1266 The qXfer:btrace:read packet supports a new annex 'delta' to read
1267 branch trace incrementally.
1271 ** Valid Python operations on gdb.Value objects representing
1272 structs/classes invoke the corresponding overloaded operators if
1274 ** New `Xmethods' feature in the Python API. Xmethods are
1275 additional methods or replacements for existing methods of a C++
1276 class. This feature is useful for those cases where a method
1277 defined in C++ source code could be inlined or optimized out by
1278 the compiler, making it unavailable to GDB.
1281 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1283 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1284 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1285 its alias "share", instead.
1287 * The commands "set remotebaud" and "show remotebaud" are no longer
1288 supported. Use "set serial baud" and "show serial baud" (respectively)
1293 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1294 target-async". The latter is left as a deprecated alias of the
1295 former for backward compatibility. If the target supports it,
1296 CLI background execution commands are now always possible by
1297 default, independently of whether the frontend stated a
1298 preference for asynchronous execution with "-gdb-set mi-async".
1299 Previously "-gdb-set target-async off" affected both MI execution
1300 commands and CLI execution commands.
1302 *** Changes in GDB 7.7
1304 * Improved support for process record-replay and reverse debugging on
1305 arm*-linux* targets. Support for thumb32 and syscall instruction
1306 recording has been added.
1308 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1310 * GDB now supports Fission DWP file format version 2.
1311 http://gcc.gnu.org/wiki/DebugFission
1313 * New convenience function "$_isvoid", to check whether an expression
1314 is void. A void expression is an expression where the type of the
1315 result is "void". For example, some convenience variables may be
1316 "void" when evaluated (e.g., "$_exitcode" before the execution of
1317 the program being debugged; or an undefined convenience variable).
1318 Another example, when calling a function whose return type is
1321 * The "maintenance print objfiles" command now takes an optional regexp.
1323 * The "catch syscall" command now works on arm*-linux* targets.
1325 * GDB now consistently shows "<not saved>" when printing values of
1326 registers the debug info indicates have not been saved in the frame
1327 and there's nowhere to retrieve them from
1328 (callee-saved/call-clobbered registers):
1333 (gdb) info registers rax
1336 Before, the former would print "<optimized out>", and the latter
1337 "*value not available*".
1339 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1344 ** Frame filters and frame decorators have been added.
1345 ** Temporary breakpoints are now supported.
1346 ** Line tables representation has been added.
1347 ** New attribute 'parent_type' for gdb.Field objects.
1348 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1349 ** New attribute 'name' for gdb.Type objects.
1353 Nios II ELF nios2*-*-elf
1354 Nios II GNU/Linux nios2*-*-linux
1355 Texas Instruments MSP430 msp430*-*-elf
1357 * Removed native configurations
1359 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1360 been removed. ELF variants of these configurations are kept supported.
1362 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1363 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1364 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1365 i[34567]86-*-openbsd3.[0-3]
1366 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1367 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1368 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1372 Like "catch throw", but catches a re-thrown exception.
1373 maint check-psymtabs
1374 Renamed from old "maint check-symtabs".
1376 Perform consistency checks on symtabs.
1377 maint expand-symtabs
1378 Expand symtabs matching an optional regexp.
1381 Display the details of GDB configure-time options.
1383 maint set|show per-command
1384 maint set|show per-command space
1385 maint set|show per-command time
1386 maint set|show per-command symtab
1387 Enable display of per-command gdb resource usage.
1389 remove-symbol-file FILENAME
1390 remove-symbol-file -a ADDRESS
1391 Remove a symbol file added via add-symbol-file. The file to remove
1392 can be identified by its filename or by an address that lies within
1393 the boundaries of this symbol file in memory.
1396 info exceptions REGEXP
1397 Display the list of Ada exceptions defined in the program being
1398 debugged. If provided, only the exceptions whose names match REGEXP
1403 set debug symfile off|on
1405 Control display of debugging info regarding reading symbol files and
1406 symbol tables within those files
1408 set print raw frame-arguments
1409 show print raw frame-arguments
1410 Set/show whether to print frame arguments in raw mode,
1411 disregarding any defined pretty-printers.
1413 set remote trace-status-packet
1414 show remote trace-status-packet
1415 Set/show the use of remote protocol qTStatus packet.
1419 Control display of debugging messages related to Nios II targets.
1423 Control whether target-assisted range stepping is enabled.
1425 set startup-with-shell
1426 show startup-with-shell
1427 Specifies whether Unix child processes are started via a shell or
1432 Use the target memory cache for accesses to the code segment. This
1433 improves performance of remote debugging (particularly disassembly).
1435 * You can now use a literal value 'unlimited' for options that
1436 interpret 0 or -1 as meaning "unlimited". E.g., "set
1437 trace-buffer-size unlimited" is now an alias for "set
1438 trace-buffer-size -1" and "set height unlimited" is now an alias for
1441 * The "set debug symtab-create" debugging option of GDB has been changed to
1442 accept a verbosity level. 0 means "off", 1 provides basic debugging
1443 output, and values of 2 or greater provides more verbose output.
1445 * New command-line options
1447 Display the details of GDB configure-time options.
1449 * The command 'tsave' can now support new option '-ctf' to save trace
1450 buffer in Common Trace Format.
1452 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1455 * GDB now implements the the C++ 'typeid' operator.
1457 * The new convenience variable $_exception holds the exception being
1458 thrown or caught at an exception-related catchpoint.
1460 * The exception-related catchpoints, like "catch throw", now accept a
1461 regular expression which can be used to filter exceptions by type.
1463 * The new convenience variable $_exitsignal is automatically set to
1464 the terminating signal number when the program being debugged dies
1465 due to an uncaught signal.
1469 ** All MI commands now accept an optional "--language" option.
1470 Support for this feature can be verified by using the "-list-features"
1471 command, which should contain "language-option".
1473 ** The new command -info-gdb-mi-command allows the user to determine
1474 whether a GDB/MI command is supported or not.
1476 ** The "^error" result record returned when trying to execute an undefined
1477 GDB/MI command now provides a variable named "code" whose content is the
1478 "undefined-command" error code. Support for this feature can be verified
1479 by using the "-list-features" command, which should contain
1480 "undefined-command-error-code".
1482 ** The -trace-save MI command can optionally save trace buffer in Common
1485 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1487 ** The command -data-list-register-values now accepts an optional
1488 "--skip-unavailable" option. When used, only the available registers
1491 ** The new command -trace-frame-collected dumps collected variables,
1492 computed expressions, tvars, memory and registers in a traceframe.
1494 ** The commands -stack-list-locals, -stack-list-arguments and
1495 -stack-list-variables now accept an option "--skip-unavailable".
1496 When used, only the available locals or arguments are displayed.
1498 ** The -exec-run command now accepts an optional "--start" option.
1499 When used, the command follows the same semantics as the "start"
1500 command, stopping the program's execution at the start of its
1501 main subprogram. Support for this feature can be verified using
1502 the "-list-features" command, which should contain
1503 "exec-run-start-option".
1505 ** The new commands -catch-assert and -catch-exceptions insert
1506 catchpoints stopping the program when Ada exceptions are raised.
1508 ** The new command -info-ada-exceptions provides the equivalent of
1509 the new "info exceptions" command.
1511 * New system-wide configuration scripts
1512 A GDB installation now provides scripts suitable for use as system-wide
1513 configuration scripts for the following systems:
1517 * GDB now supports target-assigned range stepping with remote targets.
1518 This improves the performance of stepping source lines by reducing
1519 the number of control packets from/to GDB. See "New remote packets"
1522 * GDB now understands the element 'tvar' in the XML traceframe info.
1523 It has the id of the collected trace state variables.
1525 * On S/390 targets that provide the transactional-execution feature,
1526 the program interruption transaction diagnostic block (TDB) is now
1527 represented as a number of additional "registers" in GDB.
1529 * New remote packets
1533 The vCont packet supports a new 'r' action, that tells the remote
1534 stub to step through an address range itself, without GDB
1535 involvemement at each single-step.
1537 qXfer:libraries-svr4:read's annex
1538 The previously unused annex of the qXfer:libraries-svr4:read packet
1539 is now used to support passing an argument list. The remote stub
1540 reports support for this argument list to GDB's qSupported query.
1541 The defined arguments are "start" and "prev", used to reduce work
1542 necessary for library list updating, resulting in significant
1545 * New features in the GDB remote stub, GDBserver
1547 ** GDBserver now supports target-assisted range stepping. Currently
1548 enabled on x86/x86_64 GNU/Linux targets.
1550 ** GDBserver now adds element 'tvar' in the XML in the reply to
1551 'qXfer:traceframe-info:read'. It has the id of the collected
1552 trace state variables.
1554 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1557 * New 'z' formatter for printing and examining memory, this displays the
1558 value as hexadecimal zero padded on the left to the size of the type.
1560 * GDB can now use Windows x64 unwinding data.
1562 * The "set remotebaud" command has been replaced by "set serial baud".
1563 Similarly, "show remotebaud" has been replaced by "show serial baud".
1564 The "set remotebaud" and "show remotebaud" commands are still available
1565 to provide backward compatibility with older versions of GDB.
1567 *** Changes in GDB 7.6
1569 * Target record has been renamed to record-full.
1570 Record/replay is now enabled with the "record full" command.
1571 This also affects settings that are associated with full record/replay
1572 that have been moved from "set/show record" to "set/show record full":
1574 set|show record full insn-number-max
1575 set|show record full stop-at-limit
1576 set|show record full memory-query
1578 * A new record target "record-btrace" has been added. The new target
1579 uses hardware support to record the control-flow of a process. It
1580 does not support replaying the execution, but it implements the
1581 below new commands for investigating the recorded execution log.
1582 This new recording method can be enabled using:
1586 The "record-btrace" target is only available on Intel Atom processors
1587 and requires a Linux kernel 2.6.32 or later.
1589 * Two new commands have been added for record/replay to give information
1590 about the recorded execution without having to replay the execution.
1591 The commands are only supported by "record btrace".
1593 record instruction-history prints the execution history at
1594 instruction granularity
1596 record function-call-history prints the execution history at
1597 function granularity
1599 * New native configurations
1601 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1602 FreeBSD/powerpc powerpc*-*-freebsd
1603 x86_64/Cygwin x86_64-*-cygwin*
1604 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1608 ARM AArch64 aarch64*-*-elf
1609 ARM AArch64 GNU/Linux aarch64*-*-linux
1610 Lynx 178 PowerPC powerpc-*-lynx*178
1611 x86_64/Cygwin x86_64-*-cygwin*
1612 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1614 * If the configured location of system.gdbinit file (as given by the
1615 --with-system-gdbinit option at configure time) is in the
1616 data-directory (as specified by --with-gdb-datadir at configure
1617 time) or in one of its subdirectories, then GDB will look for the
1618 system-wide init file in the directory specified by the
1619 --data-directory command-line option.
1621 * New command line options:
1623 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1624 other initialization files, unlike -nx which disables all of them.
1626 * Removed command line options
1628 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1631 * The 'ptype' and 'whatis' commands now accept an argument to control
1634 * 'info proc' now works on some core files.
1638 ** Vectors can be created with gdb.Type.vector.
1640 ** Python's atexit.register now works in GDB.
1642 ** Types can be pretty-printed via a Python API.
1644 ** Python 3 is now supported (in addition to Python 2.4 or later)
1646 ** New class gdb.Architecture exposes GDB's internal representation
1647 of architecture in the Python API.
1649 ** New method Frame.architecture returns the gdb.Architecture object
1650 corresponding to the frame's architecture.
1652 * New Python-based convenience functions:
1654 ** $_memeq(buf1, buf2, length)
1655 ** $_streq(str1, str2)
1657 ** $_regex(str, regex)
1659 * The 'cd' command now defaults to using '~' (the home directory) if not
1662 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1663 default for GCC since November 2000.
1665 * The command 'forward-search' can now be abbreviated as 'fo'.
1667 * The command 'info tracepoints' can now display 'installed on target'
1668 or 'not installed on target' for each non-pending location of tracepoint.
1670 * New configure options
1672 --enable-libmcheck/--disable-libmcheck
1673 By default, development versions are built with -lmcheck on hosts
1674 that support it, in order to help track memory corruption issues.
1675 Release versions, on the other hand, are built without -lmcheck
1676 by default. The --enable-libmcheck/--disable-libmcheck configure
1677 options allow the user to override that default.
1678 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1679 This configure option allows the user to build GDB with
1680 libbabeltrace using which GDB can read Common Trace Format data.
1682 * New commands (for set/show, see "New options" below)
1685 Catch signals. This is similar to "handle", but allows commands and
1686 conditions to be attached.
1689 List the BFDs known to GDB.
1691 python-interactive [command]
1693 Start a Python interactive prompt, or evaluate the optional command
1694 and print the result of expressions.
1697 "py" is a new alias for "python".
1699 enable type-printer [name]...
1700 disable type-printer [name]...
1701 Enable or disable type printers.
1705 ** For the Renesas Super-H architecture, the "regs" command has been removed
1706 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1711 set print type methods (on|off)
1712 show print type methods
1713 Control whether method declarations are displayed by "ptype".
1714 The default is to show them.
1716 set print type typedefs (on|off)
1717 show print type typedefs
1718 Control whether typedef definitions are displayed by "ptype".
1719 The default is to show them.
1721 set filename-display basename|relative|absolute
1722 show filename-display
1723 Control the way in which filenames is displayed.
1724 The default is "relative", which preserves previous behavior.
1726 set trace-buffer-size
1727 show trace-buffer-size
1728 Request target to change the size of trace buffer.
1730 set remote trace-buffer-size-packet auto|on|off
1731 show remote trace-buffer-size-packet
1732 Control the use of the remote protocol `QTBuffer:size' packet.
1736 Control display of debugging messages related to ARM AArch64.
1739 set debug coff-pe-read
1740 show debug coff-pe-read
1741 Control display of debugging messages related to reading of COFF/PE
1746 Control display of debugging messages related to Mach-O symbols
1749 set debug notification
1750 show debug notification
1751 Control display of debugging info for async remote notification.
1755 ** Command parameter changes are now notified using new async record
1756 "=cmd-param-changed".
1757 ** Trace frame changes caused by command "tfind" are now notified using
1758 new async record "=traceframe-changed".
1759 ** The creation, deletion and modification of trace state variables
1760 are now notified using new async records "=tsv-created",
1761 "=tsv-deleted" and "=tsv-modified".
1762 ** The start and stop of process record are now notified using new
1763 async record "=record-started" and "=record-stopped".
1764 ** Memory changes are now notified using new async record
1766 ** The data-disassemble command response will include a "fullname" field
1767 containing the absolute file name when source has been requested.
1768 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1769 command, to allow pattern filling of memory areas.
1770 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1771 library load/unload events.
1772 ** The response to breakpoint commands and breakpoint async records
1773 includes an "installed" field containing a boolean state about each
1774 non-pending tracepoint location is whether installed on target or not.
1775 ** Output of the "-trace-status" command includes a "trace-file" field
1776 containing the name of the trace file being examined. This field is
1777 optional, and only present when examining a trace file.
1778 ** The "fullname" field is now always present along with the "file" field,
1779 even if the file cannot be found by GDB.
1781 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1782 You must have the LZMA library available when configuring GDB for this
1783 feature to be enabled. For more information, see:
1784 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1786 * New remote packets
1789 Set the size of trace buffer. The remote stub reports support for this
1790 packet to gdb's qSupported query.
1793 Enable Branch Trace Store (BTS)-based branch tracing for the current
1794 thread. The remote stub reports support for this packet to gdb's
1798 Disable branch tracing for the current thread. The remote stub reports
1799 support for this packet to gdb's qSupported query.
1802 Read the traced branches for the current thread. The remote stub
1803 reports support for this packet to gdb's qSupported query.
1805 *** Changes in GDB 7.5
1807 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1808 for more x32 ABI info.
1810 * GDB now supports access to MIPS DSP registers on Linux targets.
1812 * GDB now supports debugging microMIPS binaries.
1814 * The "info os" command on GNU/Linux can now display information on
1815 several new classes of objects managed by the operating system:
1816 "info os procgroups" lists process groups
1817 "info os files" lists file descriptors
1818 "info os sockets" lists internet-domain sockets
1819 "info os shm" lists shared-memory regions
1820 "info os semaphores" lists semaphores
1821 "info os msg" lists message queues
1822 "info os modules" lists loaded kernel modules
1824 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1825 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1826 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1827 options and inspect the probe arguments using the new $_probe_arg family
1828 of convenience variables. You can obtain more information about SystemTap
1829 in <http://sourceware.org/systemtap/>.
1831 * GDB now supports reversible debugging on ARM, it allows you to
1832 debug basic ARM and THUMB instructions, and provides
1833 record/replay support.
1835 * The option "symbol-reloading" has been deleted as it is no longer used.
1839 ** GDB commands implemented in Python can now be put in command class
1842 ** The "maint set python print-stack on|off" is now deleted.
1844 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1845 apply "flag enum"-style pretty-printing to any enum.
1847 ** gdb.lookup_symbol can now work when there is no current frame.
1849 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1850 the source at which the symbol was defined.
1852 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1853 method 'value'. The former indicates whether the symbol needs a
1854 frame in order to compute its value, and the latter computes the
1857 ** A new method 'referenced_value' on gdb.Value objects which can
1858 dereference pointer as well as C++ reference values.
1860 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1861 which return the global and static blocks (as gdb.Block objects),
1862 of the underlying symbol table, respectively.
1864 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1865 object associated with a PC value.
1867 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1868 of the address range occupied by code for the current source line.
1870 * Go language support.
1871 GDB now supports debugging programs written in the Go programming
1874 * GDBserver now supports stdio connections.
1875 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1877 * The binary "gdbtui" can no longer be built or installed.
1878 Use "gdb -tui" instead.
1880 * GDB will now print "flag" enums specially. A flag enum is one where
1881 all the enumerator values have no bits in common when pairwise
1882 "and"ed. When printing a value whose type is a flag enum, GDB will
1883 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1884 (gdb) print (enum E) 3
1887 * The filename part of a linespec will now match trailing components
1888 of a source file name. For example, "break gcc/expr.c:1000" will
1889 now set a breakpoint in build/gcc/expr.c, but not
1890 build/libcpp/expr.c.
1892 * The "info proc" and "generate-core-file" commands will now also
1893 work on remote targets connected to GDBserver on Linux.
1895 * The command "info catch" has been removed. It has been disabled
1896 since December 2007.
1898 * The "catch exception" and "catch assert" commands now accept
1899 a condition at the end of the command, much like the "break"
1900 command does. For instance:
1902 (gdb) catch exception Constraint_Error if Barrier = True
1904 Previously, it was possible to add a condition to such catchpoints,
1905 but it had to be done as a second step, after the catchpoint had been
1906 created, using the "condition" command.
1908 * The "info static-tracepoint-marker" command will now also work on
1909 native Linux targets with in-process agent.
1911 * GDB can now set breakpoints on inlined functions.
1913 * The .gdb_index section has been updated to include symbols for
1914 inlined functions. GDB will ignore older .gdb_index sections by
1915 default, which could cause symbol files to be loaded more slowly
1916 until their .gdb_index sections can be recreated. The new command
1917 "set use-deprecated-index-sections on" will cause GDB to use any older
1918 .gdb_index sections it finds. This will restore performance, but the
1919 ability to set breakpoints on inlined functions will be lost in symbol
1920 files with older .gdb_index sections.
1922 The .gdb_index section has also been updated to record more information
1923 about each symbol. This speeds up the "info variables", "info functions"
1924 and "info types" commands when used with programs having the .gdb_index
1925 section, as well as speeding up debugging with shared libraries using
1926 the .gdb_index section.
1928 * Ada support for GDB/MI Variable Objects has been added.
1930 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1935 ** New command -info-os is the MI equivalent of "info os".
1937 ** Output logs ("set logging" and related) now include MI output.
1941 ** "set use-deprecated-index-sections on|off"
1942 "show use-deprecated-index-sections on|off"
1943 Controls the use of deprecated .gdb_index sections.
1945 ** "catch load" and "catch unload" can be used to stop when a shared
1946 library is loaded or unloaded, respectively.
1948 ** "enable count" can be used to auto-disable a breakpoint after
1951 ** "info vtbl" can be used to show the virtual method tables for
1952 C++ and Java objects.
1954 ** "explore" and its sub commands "explore value" and "explore type"
1955 can be used to recursively explore values and types of
1956 expressions. These commands are available only if GDB is
1957 configured with '--with-python'.
1959 ** "info auto-load" shows status of all kinds of auto-loaded files,
1960 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1961 sequences of commands files, "info auto-load python-scripts"
1962 shows status of auto-loading Python script files,
1963 "info auto-load local-gdbinit" shows status of loading init file
1964 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1965 status of inferior specific thread debugging shared library loading.
1967 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1968 and "show auto-load-scripts" commands have been deprecated, use their
1969 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1970 and "show auto-load python-scripts" counterparts instead.
1972 ** "dprintf location,format,args..." creates a dynamic printf, which
1973 is basically a breakpoint that does a printf and immediately
1974 resumes your program's execution, so it is like a printf that you
1975 can insert dynamically at runtime instead of at compiletime.
1977 ** "set print symbol"
1979 Controls whether GDB attempts to display the symbol, if any,
1980 corresponding to addresses it prints. This defaults to "on", but
1981 you can set it to "off" to restore GDB's previous behavior.
1983 * Deprecated commands
1985 ** For the Renesas Super-H architecture, the "regs" command has been
1986 deprecated, and "info all-registers" should be used instead.
1990 Renesas RL78 rl78-*-elf
1991 HP OpenVMS ia64 ia64-hp-openvms*
1993 * GDBserver supports evaluation of breakpoint conditions. When
1994 support is advertised by GDBserver, GDB may be told to send the
1995 breakpoint conditions in bytecode form to GDBserver. GDBserver
1996 will only report the breakpoint trigger to GDB when its condition
2001 set mips compression
2002 show mips compression
2003 Select the compressed ISA encoding used in functions that have no symbol
2004 information available. The encoding can be set to either of:
2007 and is updated automatically from ELF file flags if available.
2009 set breakpoint condition-evaluation
2010 show breakpoint condition-evaluation
2011 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2012 GDBserver ("target"). Default option "auto" chooses the most efficient
2014 This option can improve debugger efficiency depending on the speed of the
2018 Disable auto-loading globally.
2021 Show auto-loading setting of all kinds of auto-loaded files.
2023 set auto-load gdb-scripts on|off
2024 show auto-load gdb-scripts
2025 Control auto-loading of GDB canned sequences of commands files.
2027 set auto-load python-scripts on|off
2028 show auto-load python-scripts
2029 Control auto-loading of Python script files.
2031 set auto-load local-gdbinit on|off
2032 show auto-load local-gdbinit
2033 Control loading of init file (.gdbinit) from current directory.
2035 set auto-load libthread-db on|off
2036 show auto-load libthread-db
2037 Control auto-loading of inferior specific thread debugging shared library.
2039 set auto-load scripts-directory <dir1>[:<dir2>...]
2040 show auto-load scripts-directory
2041 Set a list of directories from which to load auto-loaded scripts.
2042 Automatically loaded Python scripts and GDB scripts are located in one
2043 of the directories listed by this option.
2044 The delimiter (':' above) may differ according to the host platform.
2046 set auto-load safe-path <dir1>[:<dir2>...]
2047 show auto-load safe-path
2048 Set a list of directories from which it is safe to auto-load files.
2049 The delimiter (':' above) may differ according to the host platform.
2051 set debug auto-load on|off
2052 show debug auto-load
2053 Control display of debugging info for auto-loading the files above.
2055 set dprintf-style gdb|call|agent
2057 Control the way in which a dynamic printf is performed; "gdb"
2058 requests a GDB printf command, while "call" causes dprintf to call a
2059 function in the inferior. "agent" requests that the target agent
2060 (such as GDBserver) do the printing.
2062 set dprintf-function <expr>
2063 show dprintf-function
2064 set dprintf-channel <expr>
2065 show dprintf-channel
2066 Set the function and optional first argument to the call when using
2067 the "call" style of dynamic printf.
2069 set disconnected-dprintf on|off
2070 show disconnected-dprintf
2071 Control whether agent-style dynamic printfs continue to be in effect
2072 after GDB disconnects.
2074 * New configure options
2076 --with-auto-load-dir
2077 Configure default value for the 'set auto-load scripts-directory'
2078 setting above. It defaults to '$debugdir:$datadir/auto-load',
2079 $debugdir representing global debugging info directories (available
2080 via 'show debug-file-directory') and $datadir representing GDB's data
2081 directory (available via 'show data-directory').
2083 --with-auto-load-safe-path
2084 Configure default value for the 'set auto-load safe-path' setting
2085 above. It defaults to the --with-auto-load-dir setting.
2087 --without-auto-load-safe-path
2088 Set 'set auto-load safe-path' to '/', effectively disabling this
2091 * New remote packets
2093 z0/z1 conditional breakpoints extension
2095 The z0/z1 breakpoint insertion packets have been extended to carry
2096 a list of conditional expressions over to the remote stub depending on the
2097 condition evaluation mode. The use of this extension can be controlled
2098 via the "set remote conditional-breakpoints-packet" command.
2102 Specify the signals which the remote stub may pass to the debugged
2103 program without GDB involvement.
2105 * New command line options
2107 --init-command=FILE, -ix Like --command, -x but execute it
2108 before loading inferior.
2109 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2110 execute it before loading inferior.
2112 *** Changes in GDB 7.4
2114 * GDB now handles ambiguous linespecs more consistently; the existing
2115 FILE:LINE support has been expanded to other types of linespecs. A
2116 breakpoint will now be set on all matching locations in all
2117 inferiors, and locations will be added or removed according to
2120 * GDB now allows you to skip uninteresting functions and files when
2121 stepping with the "skip function" and "skip file" commands.
2123 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2124 and "show remote hardware-watchpoint-length-limit". These allows to
2125 set or show the maximum length limit (in bytes) of a remote
2126 target hardware watchpoint.
2128 This allows e.g. to use "unlimited" hardware watchpoints with the
2129 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2130 watchpoints are slower than real hardware watchpoints but are
2131 significantly faster than gdb software watchpoints.
2135 ** The register_pretty_printer function in module gdb.printing now takes
2136 an optional `replace' argument. If True, the new printer replaces any
2139 ** The "maint set python print-stack on|off" command has been
2140 deprecated and will be deleted in GDB 7.5.
2141 A new command: "set python print-stack none|full|message" has
2142 replaced it. Additionally, the default for "print-stack" is
2143 now "message", which just prints the error message without
2146 ** A prompt substitution hook (prompt_hook) is now available to the
2149 ** A new Python module, gdb.prompt has been added to the GDB Python
2150 modules library. This module provides functionality for
2151 escape sequences in prompts (used by set/show
2152 extended-prompt). These escape sequences are replaced by their
2153 corresponding value.
2155 ** Python commands and convenience-functions located in
2156 'data-directory'/python/gdb/command and
2157 'data-directory'/python/gdb/function are now automatically loaded
2160 ** Blocks now provide four new attributes. global_block and
2161 static_block will return the global and static blocks
2162 respectively. is_static and is_global are boolean attributes
2163 that indicate if the block is one of those two types.
2165 ** Symbols now provide the "type" attribute, the type of the symbol.
2167 ** The "gdb.breakpoint" function has been deprecated in favor of
2170 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2171 of a function. This class is based on the "finish" command
2172 available in the CLI.
2174 ** Type objects for struct and union types now allow access to
2175 the fields using standard Python dictionary (mapping) methods.
2176 For example, "some_type['myfield']" now works, as does
2177 "some_type.items()".
2179 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2182 ** A new function, "deep_items" has been added to the gdb.types
2183 module in the GDB Python modules library. This function returns
2184 an iterator over the fields of a struct or union type. Unlike
2185 the standard Python "iteritems" method, it will recursively traverse
2186 any anonymous fields.
2190 ** "*stopped" events can report several new "reason"s, such as
2193 ** Breakpoint changes are now notified using new async records, like
2194 "=breakpoint-modified".
2196 ** New command -ada-task-info.
2198 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2199 $sdir specifies the default system locations of shared libraries.
2200 $pdir specifies the directory where the libpthread used by the application
2203 GDB no longer looks in $sdir and $pdir after it has searched the directories
2204 mentioned in libthread-db-search-path. If you want to search those
2205 directories, they must be specified in libthread-db-search-path.
2206 The default value of libthread-db-search-path on GNU/Linux and Solaris
2207 systems is now "$sdir:$pdir".
2209 $pdir is not supported by gdbserver, it is currently ignored.
2210 $sdir is supported by gdbserver.
2212 * New configure option --with-iconv-bin.
2213 When using the internationalization support like the one in the GNU C
2214 library, GDB will invoke the "iconv" program to get a list of supported
2215 character sets. If this program lives in a non-standard location, one can
2216 use this option to specify where to find it.
2218 * When natively debugging programs on PowerPC BookE processors running
2219 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2220 watchpoints, which specify a mask in addition to an address to watch.
2221 The mask specifies that some bits of an address (the bits which are
2222 reset in the mask) should be ignored when matching the address accessed
2223 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2224 section in the user manual for more details.
2226 * The new option --once causes GDBserver to stop listening for connections once
2227 the first connection is made. The listening port used by GDBserver will
2228 become available after that.
2230 * New commands "info macros" and "alias" have been added.
2232 * New function parameters suffix @entry specifies value of function parameter
2233 at the time the function got called. Entry values are available only since
2239 "!" is now an alias of the "shell" command.
2240 Note that no space is needed between "!" and SHELL COMMAND.
2244 watch EXPRESSION mask MASK_VALUE
2245 The watch command now supports the mask argument which allows creation
2246 of masked watchpoints, if the current architecture supports this feature.
2248 info auto-load-scripts [REGEXP]
2249 This command was formerly named "maintenance print section-scripts".
2250 It is now generally useful and is no longer a maintenance-only command.
2252 info macro [-all] [--] MACRO
2253 The info macro command has new options `-all' and `--'. The first for
2254 printing all definitions of a macro. The second for explicitly specifying
2255 the end of arguments and the beginning of the macro name in case the macro
2256 name starts with a hyphen.
2258 collect[/s] EXPRESSIONS
2259 The tracepoint collect command now takes an optional modifier "/s"
2260 that directs it to dereference pointer-to-character types and
2261 collect the bytes of memory up to a zero byte. The behavior is
2262 similar to what you see when you use the regular print command on a
2263 string. An optional integer following the "/s" sets a bound on the
2264 number of bytes that will be collected.
2267 The trace start command now interprets any supplied arguments as a
2268 note to be recorded with the trace run, with an effect similar to
2269 setting the variable trace-notes.
2272 The trace stop command now interprets any arguments as a note to be
2273 mentioned along with the tstatus report that the trace was stopped
2274 with a command. The effect is similar to setting the variable
2277 * Tracepoints can now be enabled and disabled at any time after a trace
2278 experiment has been started using the standard "enable" and "disable"
2279 commands. It is now possible to start a trace experiment with no enabled
2280 tracepoints; GDB will display a warning, but will allow the experiment to
2281 begin, assuming that tracepoints will be enabled as needed while the trace
2284 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2285 locations with 4-byte instructions, when they were previously
2286 limited to locations with instructions of 5 bytes or longer.
2290 set debug dwarf2-read
2291 show debug dwarf2-read
2292 Turns on or off display of debugging messages related to reading
2293 DWARF debug info. The default is off.
2295 set debug symtab-create
2296 show debug symtab-create
2297 Turns on or off display of debugging messages related to symbol table
2298 creation. The default is off.
2301 show extended-prompt
2302 Set the GDB prompt, and allow escape sequences to be inserted to
2303 display miscellaneous information (see 'help set extended-prompt'
2304 for the list of sequences). This prompt (and any information
2305 accessed through the escape sequences) is updated every time the
2306 prompt is displayed.
2308 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2309 show print entry-values
2310 Set printing of frame argument values at function entry. In some cases
2311 GDB can determine the value of function argument which was passed by the
2312 function caller, even if the value was modified inside the called function.
2314 set debug entry-values
2315 show debug entry-values
2316 Control display of debugging info for determining frame argument values at
2317 function entry and virtual tail call frames.
2319 set basenames-may-differ
2320 show basenames-may-differ
2321 Set whether a source file may have multiple base names.
2322 (A "base name" is the name of a file with the directory part removed.
2323 Example: The base name of "/home/user/hello.c" is "hello.c".)
2324 If set, GDB will canonicalize file names (e.g., expand symlinks)
2325 before comparing them. Canonicalization is an expensive operation,
2326 but it allows the same file be known by more than one base name.
2327 If not set (the default), all source files are assumed to have just
2328 one base name, and gdb will do file name comparisons more efficiently.
2334 Set a user name and notes for the current and any future trace runs.
2335 This is useful for long-running and/or disconnected traces, to
2336 inform others (or yourself) as to who is running the trace, supply
2337 contact information, or otherwise explain what is going on.
2339 set trace-stop-notes
2340 show trace-stop-notes
2341 Set a note attached to the trace run, that is displayed when the
2342 trace has been stopped by a tstop command. This is useful for
2343 instance as an explanation, if you are stopping a trace run that was
2344 started by someone else.
2346 * New remote packets
2350 Dynamically enable a tracepoint in a started trace experiment.
2354 Dynamically disable a tracepoint in a started trace experiment.
2358 Set the user and notes of the trace run.
2362 Query the current status of a tracepoint.
2366 Query the minimum length of instruction at which a fast tracepoint may
2369 * Dcache size (number of lines) and line-size are now runtime-configurable
2370 via "set dcache line" and "set dcache line-size" commands.
2374 Texas Instruments TMS320C6x tic6x-*-*
2378 Renesas RL78 rl78-*-elf
2380 *** Changes in GDB 7.3.1
2382 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2384 *** Changes in GDB 7.3
2386 * GDB has a new command: "thread find [REGEXP]".
2387 It finds the thread id whose name, target id, or thread extra info
2388 matches the given regular expression.
2390 * The "catch syscall" command now works on mips*-linux* targets.
2392 * The -data-disassemble MI command now supports modes 2 and 3 for
2393 dumping the instruction opcodes.
2395 * New command line options
2397 -data-directory DIR Specify DIR as the "data-directory".
2398 This is mostly for testing purposes.
2400 * The "maint set python auto-load on|off" command has been renamed to
2401 "set auto-load-scripts on|off".
2403 * GDB has a new command: "set directories".
2404 It is like the "dir" command except that it replaces the
2405 source path list instead of augmenting it.
2407 * GDB now understands thread names.
2409 On GNU/Linux, "info threads" will display the thread name as set by
2410 prctl or pthread_setname_np.
2412 There is also a new command, "thread name", which can be used to
2413 assign a name internally for GDB to display.
2416 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2417 has been integrated into GDB.
2421 ** The function gdb.Write now accepts an optional keyword 'stream'.
2422 This keyword, when provided, will direct the output to either
2423 stdout, stderr, or GDB's logging output.
2425 ** Parameters can now be be sub-classed in Python, and in particular
2426 you may implement the get_set_doc and get_show_doc functions.
2427 This improves how Parameter set/show documentation is processed
2428 and allows for more dynamic content.
2430 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2431 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2432 have an is_valid method.
2434 ** Breakpoints can now be sub-classed in Python, and in particular
2435 you may implement a 'stop' function that is executed each time
2436 the inferior reaches that breakpoint.
2438 ** New function gdb.lookup_global_symbol looks up a global symbol.
2440 ** GDB values in Python are now callable if the value represents a
2441 function. For example, if 'some_value' represents a function that
2442 takes two integer parameters and returns a value, you can call
2443 that function like so:
2445 result = some_value (10,20)
2447 ** Module gdb.types has been added.
2448 It contains a collection of utilities for working with gdb.Types objects:
2449 get_basic_type, has_field, make_enum_dict.
2451 ** Module gdb.printing has been added.
2452 It contains utilities for writing and registering pretty-printers.
2453 New classes: PrettyPrinter, SubPrettyPrinter,
2454 RegexpCollectionPrettyPrinter.
2455 New function: register_pretty_printer.
2457 ** New commands "info pretty-printers", "enable pretty-printer" and
2458 "disable pretty-printer" have been added.
2460 ** gdb.parameter("directories") is now available.
2462 ** New function gdb.newest_frame returns the newest frame in the
2465 ** The gdb.InferiorThread class has a new "name" attribute. This
2466 holds the thread's name.
2468 ** Python Support for Inferior events.
2469 Python scripts can add observers to be notified of events
2470 occurring in the process being debugged.
2471 The following events are currently supported:
2472 - gdb.events.cont Continue event.
2473 - gdb.events.exited Inferior exited event.
2474 - gdb.events.stop Signal received, and Breakpoint hit events.
2478 ** GDB now puts template parameters in scope when debugging in an
2479 instantiation. For example, if you have:
2481 template<int X> int func (void) { return X; }
2483 then if you step into func<5>, "print X" will show "5". This
2484 feature requires proper debuginfo support from the compiler; it
2485 was added to GCC 4.5.
2487 ** The motion commands "next", "finish", "until", and "advance" now
2488 work better when exceptions are thrown. In particular, GDB will
2489 no longer lose control of the inferior; instead, the GDB will
2490 stop the inferior at the point at which the exception is caught.
2491 This functionality requires a change in the exception handling
2492 code that was introduced in GCC 4.5.
2494 * GDB now follows GCC's rules on accessing volatile objects when
2495 reading or writing target state during expression evaluation.
2496 One notable difference to prior behavior is that "print x = 0"
2497 no longer generates a read of x; the value of the assignment is
2498 now always taken directly from the value being assigned.
2500 * GDB now has some support for using labels in the program's source in
2501 linespecs. For instance, you can use "advance label" to continue
2502 execution to a label.
2504 * GDB now has support for reading and writing a new .gdb_index
2505 section. This section holds a fast index of DWARF debugging
2506 information and can be used to greatly speed up GDB startup and
2507 operation. See the documentation for `save gdb-index' for details.
2509 * The "watch" command now accepts an optional "-location" argument.
2510 When used, this causes GDB to watch the memory referred to by the
2511 expression. Such a watchpoint is never deleted due to it going out
2514 * GDB now supports thread debugging of core dumps on GNU/Linux.
2516 GDB now activates thread debugging using the libthread_db library
2517 when debugging GNU/Linux core dumps, similarly to when debugging
2518 live processes. As a result, when debugging a core dump file, GDB
2519 is now able to display pthread_t ids of threads. For example, "info
2520 threads" shows the same output as when debugging the process when it
2521 was live. In earlier releases, you'd see something like this:
2524 * 1 LWP 6780 main () at main.c:10
2526 While now you see this:
2529 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2531 It is also now possible to inspect TLS variables when debugging core
2534 When debugging a core dump generated on a machine other than the one
2535 used to run GDB, you may need to point GDB at the correct
2536 libthread_db library with the "set libthread-db-search-path"
2537 command. See the user manual for more details on this command.
2539 * When natively debugging programs on PowerPC BookE processors running
2540 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2541 which stop execution of the inferior whenever it executes an instruction
2542 at any address within the specified range. See the "PowerPC Embedded"
2543 section in the user manual for more details.
2545 * New features in the GDB remote stub, GDBserver
2547 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2548 and i686 LynxOS (version 5.x).
2550 ** GDBserver is now supported on Blackfin Linux.
2552 * New native configurations
2554 ia64 HP-UX ia64-*-hpux*
2558 Analog Devices, Inc. Blackfin Processor bfin-*
2560 * Ada task switching is now supported on sparc-elf targets when
2561 debugging a program using the Ravenscar Profile. For more information,
2562 see the "Tasking Support when using the Ravenscar Profile" section
2563 in the GDB user manual.
2565 * Guile support was removed.
2567 * New features in the GNU simulator
2569 ** The --map-info flag lists all known core mappings.
2571 ** CFI flashes may be simulated via the "cfi" device.
2573 *** Changes in GDB 7.2
2575 * Shared library support for remote targets by default
2577 When GDB is configured for a generic, non-OS specific target, like
2578 for example, --target=arm-eabi or one of the many *-*-elf targets,
2579 GDB now queries remote stubs for loaded shared libraries using the
2580 `qXfer:libraries:read' packet. Previously, shared library support
2581 was always disabled for such configurations.
2585 ** Argument Dependent Lookup (ADL)
2587 In C++ ADL lookup directs function search to the namespaces of its
2588 arguments even if the namespace has not been imported.
2598 Here the compiler will search for `foo' in the namespace of 'b'
2599 and find A::foo. GDB now supports this. This construct is commonly
2600 used in the Standard Template Library for operators.
2602 ** Improved User Defined Operator Support
2604 In addition to member operators, GDB now supports lookup of operators
2605 defined in a namespace and imported with a `using' directive, operators
2606 defined in the global scope, operators imported implicitly from an
2607 anonymous namespace, and the ADL operators mentioned in the previous
2609 GDB now also supports proper overload resolution for all the previously
2610 mentioned flavors of operators.
2612 ** static const class members
2614 Printing of static const class members that are initialized in the
2615 class definition has been fixed.
2617 * Windows Thread Information Block access.
2619 On Windows targets, GDB now supports displaying the Windows Thread
2620 Information Block (TIB) structure. This structure is visible either
2621 by using the new command `info w32 thread-information-block' or, by
2622 dereferencing the new convenience variable named `$_tlb', a
2623 thread-specific pointer to the TIB. This feature is also supported
2624 when remote debugging using GDBserver.
2626 * Static tracepoints
2628 Static tracepoints are calls in the user program into a tracing
2629 library. One such library is a port of the LTTng kernel tracer to
2630 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2631 When debugging with GDBserver, GDB now supports combining the GDB
2632 tracepoint machinery with such libraries. For example: the user can
2633 use GDB to probe a static tracepoint marker (a call from the user
2634 program into the tracing library) with the new "strace" command (see
2635 "New commands" below). This creates a "static tracepoint" in the
2636 breakpoint list, that can be manipulated with the same feature set
2637 as fast and regular tracepoints. E.g., collect registers, local and
2638 global variables, collect trace state variables, and define
2639 tracepoint conditions. In addition, the user can collect extra
2640 static tracepoint marker specific data, by collecting the new
2641 $_sdata internal variable. When analyzing the trace buffer, you can
2642 inspect $_sdata like any other variable available to GDB. For more
2643 information, see the "Tracepoints" chapter in GDB user manual. New
2644 remote packets have been defined to support static tracepoints, see
2645 the "New remote packets" section below.
2647 * Better reconstruction of tracepoints after disconnected tracing
2649 GDB will attempt to download the original source form of tracepoint
2650 definitions when starting a trace run, and then will upload these
2651 upon reconnection to the target, resulting in a more accurate
2652 reconstruction of the tracepoints that are in use on the target.
2656 You can now exercise direct control over the ways that GDB can
2657 affect your program. For instance, you can disallow the setting of
2658 breakpoints, so that the program can run continuously (assuming
2659 non-stop mode). In addition, the "observer" variable is available
2660 to switch all of the different controls; in observer mode, GDB
2661 cannot affect the target's behavior at all, which is useful for
2662 tasks like diagnosing live systems in the field.
2664 * The new convenience variable $_thread holds the number of the
2667 * New remote packets
2671 Return the address of the Windows Thread Information Block of a given thread.
2675 In response to several of the tracepoint packets, the target may now
2676 also respond with a number of intermediate `qRelocInsn' request
2677 packets before the final result packet, to have GDB handle
2678 relocating an instruction to execute at a different address. This
2679 is particularly useful for stubs that support fast tracepoints. GDB
2680 reports support for this feature in the qSupported packet.
2684 List static tracepoint markers in the target program.
2688 List static tracepoint markers at a given address in the target
2691 qXfer:statictrace:read
2693 Read the static trace data collected (by a `collect $_sdata'
2694 tracepoint action). The remote stub reports support for this packet
2695 to gdb's qSupported query.
2699 Send the current settings of GDB's permission flags.
2703 Send part of the source (textual) form of a tracepoint definition,
2704 which includes location, conditional, and action list.
2706 * The source command now accepts a -s option to force searching for the
2707 script in the source search path even if the script name specifies
2710 * New features in the GDB remote stub, GDBserver
2712 - GDBserver now support tracepoints (including fast tracepoints, and
2713 static tracepoints). The feature is currently supported by the
2714 i386-linux and amd64-linux builds. See the "Tracepoints support
2715 in gdbserver" section in the manual for more information.
2717 GDBserver JIT compiles the tracepoint's conditional agent
2718 expression bytecode into native code whenever possible for low
2719 overhead dynamic tracepoints conditionals. For such tracepoints,
2720 an expression that examines program state is evaluated when the
2721 tracepoint is reached, in order to determine whether to capture
2722 trace data. If the condition is simple and false, processing the
2723 tracepoint finishes very quickly and no data is gathered.
2725 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2726 for static tracepoints support.
2728 - GDBserver now supports x86_64 Windows 64-bit debugging.
2730 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2731 it understands register description.
2733 * The --batch flag now disables pagination and queries.
2735 * X86 general purpose registers
2737 GDB now supports reading/writing byte, word and double-word x86
2738 general purpose registers directly. This means you can use, say,
2739 $ah or $ax to refer, respectively, to the byte register AH and
2740 16-bit word register AX that are actually portions of the 32-bit
2741 register EAX or 64-bit register RAX.
2743 * The `commands' command now accepts a range of breakpoints to modify.
2744 A plain `commands' following a command that creates multiple
2745 breakpoints affects all the breakpoints set by that command. This
2746 applies to breakpoints set by `rbreak', and also applies when a
2747 single `break' command creates multiple breakpoints (e.g.,
2748 breakpoints on overloaded c++ functions).
2750 * The `rbreak' command now accepts a filename specification as part of
2751 its argument, limiting the functions selected by the regex to those
2752 in the specified file.
2754 * Support for remote debugging Windows and SymbianOS shared libraries
2755 from Unix hosts has been improved. Non Windows GDB builds now can
2756 understand target reported file names that follow MS-DOS based file
2757 system semantics, such as file names that include drive letters and
2758 use the backslash character as directory separator. This makes it
2759 possible to transparently use the "set sysroot" and "set
2760 solib-search-path" on Unix hosts to point as host copies of the
2761 target's shared libraries. See the new command "set
2762 target-file-system-kind" described below, and the "Commands to
2763 specify files" section in the user manual for more information.
2767 eval template, expressions...
2768 Convert the values of one or more expressions under the control
2769 of the string template to a command line, and call it.
2771 set target-file-system-kind unix|dos-based|auto
2772 show target-file-system-kind
2773 Set or show the assumed file system kind for target reported file
2776 save breakpoints <filename>
2777 Save all current breakpoint definitions to a file suitable for use
2778 in a later debugging session. To read the saved breakpoint
2779 definitions, use the `source' command.
2781 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2784 info static-tracepoint-markers
2785 Display information about static tracepoint markers in the target.
2787 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2788 Define a static tracepoint by probing a marker at the given
2789 function, line, address, or marker ID.
2793 Enable and disable observer mode.
2795 set may-write-registers on|off
2796 set may-write-memory on|off
2797 set may-insert-breakpoints on|off
2798 set may-insert-tracepoints on|off
2799 set may-insert-fast-tracepoints on|off
2800 set may-interrupt on|off
2801 Set individual permissions for GDB effects on the target. Note that
2802 some of these settings can have undesirable or surprising
2803 consequences, particularly when changed in the middle of a session.
2804 For instance, disabling the writing of memory can prevent
2805 breakpoints from being inserted, cause single-stepping to fail, or
2806 even crash your program, if you disable after breakpoints have been
2807 inserted. However, GDB should not crash.
2809 set record memory-query on|off
2810 show record memory-query
2811 Control whether to stop the inferior if memory changes caused
2812 by an instruction cannot be recorded.
2817 The disassemble command now supports "start,+length" form of two arguments.
2821 ** GDB now provides a new directory location, called the python directory,
2822 where Python scripts written for GDB can be installed. The location
2823 of that directory is <data-directory>/python, where <data-directory>
2824 is the GDB data directory. For more details, see section `Scripting
2825 GDB using Python' in the manual.
2827 ** The GDB Python API now has access to breakpoints, symbols, symbol
2828 tables, program spaces, inferiors, threads and frame's code blocks.
2829 Additionally, GDB Parameters can now be created from the API, and
2830 manipulated via set/show in the CLI.
2832 ** New functions gdb.target_charset, gdb.target_wide_charset,
2833 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2835 ** New exception gdb.GdbError.
2837 ** Pretty-printers are now also looked up in the current program space.
2839 ** Pretty-printers can now be individually enabled and disabled.
2841 ** GDB now looks for names of Python scripts to auto-load in a
2842 special section named `.debug_gdb_scripts', in addition to looking
2843 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2845 * Tracepoint actions were unified with breakpoint commands. In particular,
2846 there are no longer differences in "info break" output for breakpoints and
2847 tracepoints and the "commands" command can be used for both tracepoints and
2848 regular breakpoints.
2852 ARM Symbian arm*-*-symbianelf*
2854 * D language support.
2855 GDB now supports debugging programs written in the D programming
2858 * GDB now supports the extended ptrace interface for PowerPC which is
2859 available since Linux kernel version 2.6.34. This automatically enables
2860 any hardware breakpoints and additional hardware watchpoints available in
2861 the processor. The old ptrace interface exposes just one hardware
2862 watchpoint and no hardware breakpoints.
2864 * GDB is now able to use the Data Value Compare (DVC) register available on
2865 embedded PowerPC processors to implement in hardware simple watchpoint
2866 conditions of the form:
2868 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2870 This works in native GDB running on Linux kernels with the extended ptrace
2871 interface mentioned above.
2873 *** Changes in GDB 7.1
2877 ** Namespace Support
2879 GDB now supports importing of namespaces in C++. This enables the
2880 user to inspect variables from imported namespaces. Support for
2881 namepace aliasing has also been added. So, if a namespace is
2882 aliased in the current scope (e.g. namepace C=A; ) the user can
2883 print variables using the alias (e.g. (gdb) print C::x).
2887 All known bugs relating to the printing of virtual base class were
2888 fixed. It is now possible to call overloaded static methods using a
2893 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2894 and reinterpret_cast<> are now handled by the C++ expression parser.
2898 Xilinx MicroBlaze microblaze-*-*
2903 Xilinx MicroBlaze microblaze
2906 * Multi-program debugging.
2908 GDB now has support for multi-program (a.k.a. multi-executable or
2909 multi-exec) debugging. This allows for debugging multiple inferiors
2910 simultaneously each running a different program under the same GDB
2911 session. See "Debugging Multiple Inferiors and Programs" in the
2912 manual for more information. This implied some user visible changes
2913 in the multi-inferior support. For example, "info inferiors" now
2914 lists inferiors that are not running yet or that have exited
2915 already. See also "New commands" and "New options" below.
2917 * New tracing features
2919 GDB's tracepoint facility now includes several new features:
2921 ** Trace state variables
2923 GDB tracepoints now include support for trace state variables, which
2924 are variables managed by the target agent during a tracing
2925 experiment. They are useful for tracepoints that trigger each
2926 other, so for instance one tracepoint can count hits in a variable,
2927 and then a second tracepoint has a condition that is true when the
2928 count reaches a particular value. Trace state variables share the
2929 $-syntax of GDB convenience variables, and can appear in both
2930 tracepoint actions and condition expressions. Use the "tvariable"
2931 command to create, and "info tvariables" to view; see "Trace State
2932 Variables" in the manual for more detail.
2936 GDB now includes an option for defining fast tracepoints, which
2937 targets may implement more efficiently, such as by installing a jump
2938 into the target agent rather than a trap instruction. The resulting
2939 speedup can be by two orders of magnitude or more, although the
2940 tradeoff is that some program locations on some target architectures
2941 might not allow fast tracepoint installation, for instance if the
2942 instruction to be replaced is shorter than the jump. To request a
2943 fast tracepoint, use the "ftrace" command, with syntax identical to
2944 the regular trace command.
2946 ** Disconnected tracing
2948 It is now possible to detach GDB from the target while it is running
2949 a trace experiment, then reconnect later to see how the experiment
2950 is going. In addition, a new variable disconnected-tracing lets you
2951 tell the target agent whether to continue running a trace if the
2952 connection is lost unexpectedly.
2956 GDB now has the ability to save the trace buffer into a file, and
2957 then use that file as a target, similarly to you can do with
2958 corefiles. You can select trace frames, print data that was
2959 collected in them, and use tstatus to display the state of the
2960 tracing run at the moment that it was saved. To create a trace
2961 file, use "tsave <filename>", and to use it, do "target tfile
2964 ** Circular trace buffer
2966 You can ask the target agent to handle the trace buffer as a
2967 circular buffer, discarding the oldest trace frames to make room for
2968 newer ones, by setting circular-trace-buffer to on. This feature may
2969 not be available for all target agents.
2974 The disassemble command, when invoked with two arguments, now requires
2975 the arguments to be comma-separated.
2978 The info variables command now displays variable definitions. Files
2979 which only declare a variable are not shown.
2982 The source command is now capable of sourcing Python scripts.
2983 This feature is dependent on the debugger being build with Python
2986 Related to this enhancement is also the introduction of a new command
2987 "set script-extension" (see below).
2989 * New commands (for set/show, see "New options" below)
2991 record save [<FILENAME>]
2992 Save a file (in core file format) containing the process record
2993 execution log for replay debugging at a later time.
2995 record restore <FILENAME>
2996 Restore the process record execution log that was saved at an
2997 earlier time, for replay debugging.
2999 add-inferior [-copies <N>] [-exec <FILENAME>]
3002 clone-inferior [-copies <N>] [ID]
3003 Make a new inferior ready to execute the same program another
3004 inferior has loaded.
3009 maint info program-spaces
3010 List the program spaces loaded into GDB.
3012 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3013 show remote interrupt-sequence
3014 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3015 as the sequence to the remote target in order to interrupt the execution.
3016 Ctrl-C is a default. Some system prefers BREAK which is high level of
3017 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3018 Magic SysRq g. It is BREAK signal and character 'g'.
3020 set remote interrupt-on-connect [on | off]
3021 show remote interrupt-on-connect
3022 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3023 remote target when gdb connects to it. This is needed when you debug
3026 set remotebreak [on | off]
3028 Deprecated. Use "set/show remote interrupt-sequence" instead.
3030 tvariable $NAME [ = EXP ]
3031 Create or modify a trace state variable.
3034 List trace state variables and their values.
3036 delete tvariable $NAME ...
3037 Delete one or more trace state variables.
3040 Evaluate the given expressions without collecting anything into the
3041 trace buffer. (Valid in tracepoint actions only.)
3043 ftrace FN / FILE:LINE / *ADDR
3044 Define a fast tracepoint at the given function, line, or address.
3046 * New expression syntax
3048 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3049 GDB now parses 0b101010 identically with 42.
3053 set follow-exec-mode new|same
3054 show follow-exec-mode
3055 Control whether GDB reuses the same inferior across an exec call or
3056 creates a new one. This is useful to be able to restart the old
3057 executable after the inferior having done an exec call.
3059 set default-collect EXPR, ...
3060 show default-collect
3061 Define a list of expressions to be collected at each tracepoint.
3062 This is a useful way to ensure essential items are not overlooked,
3063 such as registers or a critical global variable.
3065 set disconnected-tracing
3066 show disconnected-tracing
3067 If set to 1, the target is instructed to continue tracing if it
3068 loses its connection to GDB. If 0, the target is to stop tracing
3071 set circular-trace-buffer
3072 show circular-trace-buffer
3073 If set to on, the target is instructed to use a circular trace buffer
3074 and discard the oldest trace frames instead of stopping the trace due
3075 to a full trace buffer. If set to off, the trace stops when the buffer
3076 fills up. Some targets may not support this.
3078 set script-extension off|soft|strict
3079 show script-extension
3080 If set to "off", the debugger does not perform any script language
3081 recognition, and all sourced files are assumed to be GDB scripts.
3082 If set to "soft" (the default), files are sourced according to
3083 filename extension, falling back to GDB scripts if the first
3085 If set to "strict", files are sourced according to filename extension.
3087 set ada trust-PAD-over-XVS on|off
3088 show ada trust-PAD-over-XVS
3089 If off, activate a workaround against a bug in the debugging information
3090 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3091 the GCC sources for more information about the GNAT encoding and
3092 PAD types in particular). It is always safe to set this option to
3093 off, but this introduces a slight performance penalty. The default
3096 * Python API Improvements
3098 ** GDB provides the new class gdb.LazyString. This is useful in
3099 some pretty-printing cases. The new method gdb.Value.lazy_string
3100 provides a simple way to create objects of this type.
3102 ** The fields returned by gdb.Type.fields now have an
3103 `is_base_class' attribute.
3105 ** The new method gdb.Type.range returns the range of an array type.
3107 ** The new method gdb.parse_and_eval can be used to parse and
3108 evaluate an expression.
3110 * New remote packets
3113 Define a trace state variable.
3116 Get the current value of a trace state variable.
3119 Set desired tracing behavior upon disconnection.
3122 Set the trace buffer to be linear or circular.
3125 Get data about the tracepoints currently in use.
3129 Process record now works correctly with hardware watchpoints.
3131 Multiple bug fixes have been made to the mips-irix port, making it
3132 much more reliable. In particular:
3133 - Debugging threaded applications is now possible again. Previously,
3134 GDB would hang while starting the program, or while waiting for
3135 the program to stop at a breakpoint.
3136 - Attaching to a running process no longer hangs.
3137 - An error occurring while loading a core file has been fixed.
3138 - Changing the value of the PC register now works again. This fixes
3139 problems observed when using the "jump" command, or when calling
3140 a function from GDB, or even when assigning a new value to $pc.
3141 - With the "finish" and "return" commands, the return value for functions
3142 returning a small array is now correctly printed.
3143 - It is now possible to break on shared library code which gets executed
3144 during a shared library init phase (code executed while executing
3145 their .init section). Previously, the breakpoint would have no effect.
3146 - GDB is now able to backtrace through the signal handler for
3147 non-threaded programs.
3149 PIE (Position Independent Executable) programs debugging is now supported.
3150 This includes debugging execution of PIC (Position Independent Code) shared
3151 libraries although for that, it should be possible to run such libraries as an
3154 *** Changes in GDB 7.0
3156 * GDB now has an interface for JIT compilation. Applications that
3157 dynamically generate code can create symbol files in memory and register
3158 them with GDB. For users, the feature should work transparently, and
3159 for JIT developers, the interface is documented in the GDB manual in the
3160 "JIT Compilation Interface" chapter.
3162 * Tracepoints may now be conditional. The syntax is as for
3163 breakpoints; either an "if" clause appended to the "trace" command,
3164 or the "condition" command is available. GDB sends the condition to
3165 the target for evaluation using the same bytecode format as is used
3166 for tracepoint actions.
3168 * The disassemble command now supports: an optional /r modifier, print the
3169 raw instructions in hex as well as in symbolic form, and an optional /m
3170 modifier to print mixed source+assembly.
3172 * Process record and replay
3174 In a architecture environment that supports ``process record and
3175 replay'', ``process record and replay'' target can record a log of
3176 the process execution, and replay it with both forward and reverse
3179 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3180 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3181 set execution-direction {forward|reverse}, for targets that support
3184 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3185 feature is available with a native GDB running on kernel version
3188 * GDB now has support for multi-byte and wide character sets on the
3189 target. Strings whose character type is wchar_t, char16_t, or
3190 char32_t are now correctly printed. GDB supports wide- and unicode-
3191 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3192 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3193 `printf'. This feature requires iconv to work properly; if your
3194 system does not have a working iconv, GDB can use GNU libiconv. See
3195 the installation instructions for more information.
3197 * GDB now supports automatic retrieval of shared library files from
3198 remote targets. To use this feature, specify a system root that begins
3199 with the `remote:' prefix, either via the `set sysroot' command or via
3200 the `--with-sysroot' configure-time option.
3202 * "info sharedlibrary" now takes an optional regex of libraries to show,
3203 and it now reports if a shared library has no debugging information.
3205 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3206 now complete on file names.
3208 * When completing in expressions, gdb will attempt to limit
3209 completions to allowable structure or union fields, where appropriate.
3210 For instance, consider:
3212 # struct example { int f1; double f2; };
3213 # struct example variable;
3216 If the user types TAB at the end of this command line, the available
3217 completions will be "f1" and "f2".
3219 * Inlined functions are now supported. They show up in backtraces, and
3220 the "step", "next", and "finish" commands handle them automatically.
3222 * GDB now supports the token-splicing (##) and stringification (#)
3223 operators when expanding macros. It also supports variable-arity
3226 * GDB now supports inspecting extra signal information, exported by
3227 the new $_siginfo convenience variable. The feature is currently
3228 implemented on linux ARM, i386 and amd64.
3230 * GDB can now display the VFP floating point registers and NEON vector
3231 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3232 can provide these registers (requires Linux 2.6.30 or later). Remote
3233 and simulator targets may also provide them.
3235 * New remote packets
3238 Search memory for a sequence of bytes.
3241 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3242 operation over reliable transport links. Use of this packet is
3243 controlled by the `set remote noack-packet' command.
3246 Kill the process with the specified process ID. Use this in preference
3247 to `k' when multiprocess protocol extensions are supported.
3250 Obtains additional operating system information
3254 Read or write additional signal information.
3256 * Removed remote protocol undocumented extension
3258 An undocumented extension to the remote protocol's `S' stop reply
3259 packet that permited the stub to pass a process id was removed.
3260 Remote servers should use the `T' stop reply packet instead.
3262 * GDB now supports multiple function calling conventions according to the
3263 DWARF-2 DW_AT_calling_convention function attribute.
3265 * The SH target utilizes the aforementioned change to distinguish between gcc
3266 and Renesas calling convention. It also adds the new CLI commands
3267 `set/show sh calling-convention'.
3269 * GDB can now read compressed debug sections, as produced by GNU gold
3270 with the --compress-debug-sections=zlib flag.
3272 * 64-bit core files are now supported on AIX.
3274 * Thread switching is now supported on Tru64.
3276 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3277 which will be allocated using malloc later in program execution.
3279 * The qXfer:libraries:read remote procotol packet now allows passing a
3280 list of section offsets.
3282 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3283 conditions handling signals delivered during attach or thread creation
3284 have also been fixed.
3286 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3287 From the user's standpoint, all unqualified instances of True and False
3288 are treated as the standard definitions, regardless of context.
3290 * GDB now parses C++ symbol and type names more flexibly. For
3293 template<typename T> class C { };
3296 GDB will now correctly handle all of:
3298 ptype C<char const *>
3299 ptype C<char const*>
3300 ptype C<const char *>
3301 ptype C<const char*>
3303 * New features in the GDB remote stub, gdbserver
3305 - The "--wrapper" command-line argument tells gdbserver to use a
3306 wrapper program to launch programs for debugging.
3308 - On PowerPC and S/390 targets, it is now possible to use a single
3309 gdbserver executable to debug both 32-bit and 64-bit programs.
3310 (This requires gdbserver itself to be built as a 64-bit executable.)
3312 - gdbserver uses the new noack protocol mode for TCP connections to
3313 reduce communications latency, if also supported and enabled in GDB.
3315 - Support for the sparc64-linux-gnu target is now included in
3318 - The amd64-linux build of gdbserver now supports debugging both
3319 32-bit and 64-bit programs.
3321 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3322 now support hardware watchpoints, and will use them automatically
3327 GDB now has support for scripting using Python. Whether this is
3328 available is determined at configure time.
3330 New GDB commands can now be written in Python.
3332 * Ada tasking support
3334 Ada tasks can now be inspected in GDB. The following commands have
3338 Print the list of Ada tasks.
3340 Print detailed information about task number N.
3342 Print the task number of the current task.
3344 Switch the context of debugging to task number N.
3346 * Support for user-defined prefixed commands. The "define" command can
3347 add new commands to existing prefixes, e.g. "target".
3349 * Multi-inferior, multi-process debugging.
3351 GDB now has generalized support for multi-inferior debugging. See
3352 "Debugging Multiple Inferiors" in the manual for more information.
3353 Although availability still depends on target support, the command
3354 set is more uniform now. The GNU/Linux specific multi-forks support
3355 has been migrated to this new framework. This implied some user
3356 visible changes; see "New commands" and also "Removed commands"
3359 * Target descriptions can now describe the target OS ABI. See the
3360 "Target Description Format" section in the user manual for more
3363 * Target descriptions can now describe "compatible" architectures
3364 to indicate that the target can execute applications for a different
3365 architecture in addition to those for the main target architecture.
3366 See the "Target Description Format" section in the user manual for
3369 * Multi-architecture debugging.
3371 GDB now includes general supports for debugging applications on
3372 hybrid systems that use more than one single processor architecture
3373 at the same time. Each such hybrid architecture still requires
3374 specific support to be added. The only hybrid architecture supported
3375 in this version of GDB is the Cell Broadband Engine.
3377 * GDB now supports integrated debugging of Cell/B.E. applications that
3378 use both the PPU and SPU architectures. To enable support for hybrid
3379 Cell/B.E. debugging, you need to configure GDB to support both the
3380 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3381 --enable-targets configure option.
3383 * Non-stop mode debugging.
3385 For some targets, GDB now supports an optional mode of operation in
3386 which you can examine stopped threads while other threads continue
3387 to execute freely. This is referred to as non-stop mode, with the
3388 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3389 section in the user manual for more information.
3391 To be able to support remote non-stop debugging, a remote stub needs
3392 to implement the non-stop mode remote protocol extensions, as
3393 described in the "Remote Non-Stop" section of the user manual. The
3394 GDB remote stub, gdbserver, has been adjusted to support these
3395 extensions on linux targets.
3397 * New commands (for set/show, see "New options" below)
3399 catch syscall [NAME(S) | NUMBER(S)]
3400 Catch system calls. Arguments, which should be names of system
3401 calls or their numbers, mean catch only those syscalls. Without
3402 arguments, every syscall will be caught. When the inferior issues
3403 any of the specified syscalls, GDB will stop and announce the system
3404 call, both when it is called and when its call returns. This
3405 feature is currently available with a native GDB running on the
3406 Linux Kernel, under the following architectures: x86, x86_64,
3407 PowerPC and PowerPC64.
3409 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3411 Search memory for a sequence of bytes.
3413 maint set python print-stack
3414 maint show python print-stack
3415 Show a stack trace when an error is encountered in a Python script.
3418 Invoke CODE by passing it to the Python interpreter.
3423 These allow macros to be defined, undefined, and listed
3427 Show operating system information about processes.
3430 List the inferiors currently under GDB's control.
3433 Switch focus to inferior number NUM.
3436 Detach from inferior number NUM.
3439 Kill inferior number NUM.
3443 set spu stop-on-load
3444 show spu stop-on-load
3445 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3447 set spu auto-flush-cache
3448 show spu auto-flush-cache
3449 Control whether to automatically flush the software-managed cache
3450 during Cell/B.E. debugging.
3452 set sh calling-convention
3453 show sh calling-convention
3454 Control the calling convention used when calling SH target functions.
3457 show debug timestamp
3458 Control display of timestamps with GDB debugging output.
3460 set disassemble-next-line
3461 show disassemble-next-line
3462 Control display of disassembled source lines or instructions when
3465 set remote noack-packet
3466 show remote noack-packet
3467 Set/show the use of remote protocol QStartNoAckMode packet. See above
3468 under "New remote packets."
3470 set remote query-attached-packet
3471 show remote query-attached-packet
3472 Control use of remote protocol `qAttached' (query-attached) packet.
3474 set remote read-siginfo-object
3475 show remote read-siginfo-object
3476 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3479 set remote write-siginfo-object
3480 show remote write-siginfo-object
3481 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3484 set remote reverse-continue
3485 show remote reverse-continue
3486 Control use of remote protocol 'bc' (reverse-continue) packet.
3488 set remote reverse-step
3489 show remote reverse-step
3490 Control use of remote protocol 'bs' (reverse-step) packet.
3492 set displaced-stepping
3493 show displaced-stepping
3494 Control displaced stepping mode. Displaced stepping is a way to
3495 single-step over breakpoints without removing them from the debuggee.
3496 Also known as "out-of-line single-stepping".
3499 show debug displaced
3500 Control display of debugging info for displaced stepping.
3502 maint set internal-error
3503 maint show internal-error
3504 Control what GDB does when an internal error is detected.
3506 maint set internal-warning
3507 maint show internal-warning
3508 Control what GDB does when an internal warning is detected.
3513 Use a wrapper program to launch programs for debugging.
3515 set multiple-symbols (all|ask|cancel)
3516 show multiple-symbols
3517 The value of this variable can be changed to adjust the debugger behavior
3518 when an expression or a breakpoint location contains an ambiguous symbol
3519 name (an overloaded function name, for instance).
3521 set breakpoint always-inserted
3522 show breakpoint always-inserted
3523 Keep breakpoints always inserted in the target, as opposed to inserting
3524 them when resuming the target, and removing them when the target stops.
3525 This option can improve debugger performance on slow remote targets.
3527 set arm fallback-mode (arm|thumb|auto)
3528 show arm fallback-mode
3529 set arm force-mode (arm|thumb|auto)
3531 These commands control how ARM GDB determines whether instructions
3532 are ARM or Thumb. The default for both settings is auto, which uses
3533 the current CPSR value for instructions without symbols; previous
3534 versions of GDB behaved as if "set arm fallback-mode arm".
3536 set disable-randomization
3537 show disable-randomization
3538 Standalone programs run with the virtual address space randomization enabled
3539 by default on some platforms. This option keeps the addresses stable across
3540 multiple debugging sessions.
3544 Control whether other threads are stopped or not when some thread hits
3549 Requests that asynchronous execution is enabled in the target, if available.
3550 In this case, it's possible to resume target in the background, and interact
3551 with GDB while the target is running. "show target-async" displays the
3552 current state of asynchronous execution of the target.
3554 set target-wide-charset
3555 show target-wide-charset
3556 The target-wide-charset is the name of the character set that GDB
3557 uses when printing characters whose type is wchar_t.
3559 set tcp auto-retry (on|off)
3561 set tcp connect-timeout
3562 show tcp connect-timeout
3563 These commands allow GDB to retry failed TCP connections to a remote stub
3564 with a specified timeout period; this is useful if the stub is launched
3565 in parallel with GDB but may not be ready to accept connections immediately.
3567 set libthread-db-search-path
3568 show libthread-db-search-path
3569 Control list of directories which GDB will search for appropriate
3572 set schedule-multiple (on|off)
3573 show schedule-multiple
3574 Allow GDB to resume all threads of all processes or only threads of
3575 the current process.
3579 Use more aggressive caching for accesses to the stack. This improves
3580 performance of remote debugging (particularly backtraces) without
3581 affecting correctness.
3583 set interactive-mode (on|off|auto)
3584 show interactive-mode
3585 Control whether GDB runs in interactive mode (on) or not (off).
3586 When in interactive mode, GDB waits for the user to answer all
3587 queries. Otherwise, GDB does not wait and assumes the default
3588 answer. When set to auto (the default), GDB determines which
3589 mode to use based on the stdin settings.
3594 For program forks, this is replaced by the new more generic `info
3595 inferiors' command. To list checkpoints, you can still use the
3596 `info checkpoints' command, which was an alias for the `info forks'
3600 Replaced by the new `inferior' command. To switch between
3601 checkpoints, you can still use the `restart' command, which was an
3602 alias for the `fork' command.
3605 This is removed, since some targets don't have a notion of
3606 processes. To switch between processes, you can still use the
3607 `inferior' command using GDB's own inferior number.
3610 For program forks, this is replaced by the new more generic `kill
3611 inferior' command. To delete a checkpoint, you can still use the
3612 `delete checkpoint' command, which was an alias for the `delete
3616 For program forks, this is replaced by the new more generic `detach
3617 inferior' command. To detach a checkpoint, you can still use the
3618 `detach checkpoint' command, which was an alias for the `detach
3621 * New native configurations
3623 x86/x86_64 Darwin i[34567]86-*-darwin*
3625 x86_64 MinGW x86_64-*-mingw*
3629 Lattice Mico32 lm32-*
3630 x86 DICOS i[34567]86-*-dicos*
3631 x86_64 DICOS x86_64-*-dicos*
3634 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3635 (mingw32ce) debugging.
3641 These commands were actually not implemented on any target.
3643 *** Changes in GDB 6.8
3645 * New native configurations
3647 NetBSD/hppa hppa*-*netbsd*
3648 Xtensa GNU/Linux xtensa*-*-linux*
3652 NetBSD/hppa hppa*-*-netbsd*
3653 Xtensa GNU/Lunux xtensa*-*-linux*
3655 * Change in command line behavior -- corefiles vs. process ids.
3657 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3658 attaching to process NUMBER fails, GDB no longer attempts to open a
3659 core file named NUMBER. Attaching to a program using the -c option
3660 is no longer supported. Instead, use the '-p' or '--pid' options.
3662 * GDB can now be built as a native debugger for debugging Windows x86
3663 (mingw32) Portable Executable (PE) programs.
3665 * Pending breakpoints no longer change their number when their address
3668 * GDB now supports breakpoints with multiple locations,
3669 including breakpoints on C++ constructors, inside C++ templates,
3670 and in inlined functions.
3672 * GDB's ability to debug optimized code has been improved. GDB more
3673 accurately identifies function bodies and lexical blocks that occupy
3674 more than one contiguous range of addresses.
3676 * Target descriptions can now describe registers for PowerPC.
3678 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3679 registers on PowerPC targets.
3681 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3682 targets even when the libthread_db library is not available.
3684 * The GDB remote stub, gdbserver, now supports the new file transfer
3685 commands (remote put, remote get, and remote delete).
3687 * The GDB remote stub, gdbserver, now supports run and attach in
3688 extended-remote mode.
3690 * hppa*64*-*-hpux11* target broken
3691 The debugger is unable to start a program and fails with the following
3692 error: "Error trying to get information about dynamic linker".
3693 The gdb-6.7 release is also affected.
3695 * GDB now supports the --enable-targets= configure option to allow
3696 building a single GDB executable that supports multiple remote
3697 target architectures.
3699 * GDB now supports debugging C and C++ programs which use the
3700 Decimal Floating Point extension. In addition, the PowerPC target
3701 now has a set of pseudo-registers to inspect decimal float values
3702 stored in two consecutive float registers.
3704 * The -break-insert MI command can optionally create pending
3707 * Improved support for debugging Ada
3708 Many improvements to the Ada language support have been made. These
3710 - Better support for Ada2005 interface types
3711 - Improved handling of arrays and slices in general
3712 - Better support for Taft-amendment types
3713 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3715 - Improved command completion in Ada
3718 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3723 set print frame-arguments (all|scalars|none)
3724 show print frame-arguments
3725 The value of this variable can be changed to control which argument
3726 values should be printed by the debugger when displaying a frame.
3731 Transfer files to and from a remote target, and delete remote files.
3738 Transfer files to and from a remote target, and delete remote files.
3740 * New remote packets
3747 Open, close, read, write, and delete files on the remote system.
3750 Attach to an existing process on the remote system, in extended-remote
3754 Run a new process on the remote system, in extended-remote mode.
3756 *** Changes in GDB 6.7
3758 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3759 bfd, libiberty and opcodes, as revealed by static analysis donated by
3760 Coverity, Inc. (http://scan.coverity.com).
3762 * When looking up multiply-defined global symbols, GDB will now prefer the
3763 symbol definition in the current shared library if it was built using the
3764 -Bsymbolic linker option.
3766 * When the Text User Interface (TUI) is not configured, GDB will now
3767 recognize the -tui command-line option and print a message that the TUI
3770 * The GDB remote stub, gdbserver, now has lower overhead for high
3771 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3773 * GDB for MIPS targets now autodetects whether a remote target provides
3774 32-bit or 64-bit register values.
3776 * Support for C++ member pointers has been improved.
3778 * GDB now understands XML target descriptions, which specify the
3779 target's overall architecture. GDB can read a description from
3780 a local file or over the remote serial protocol.
3782 * Vectors of single-byte data use a new integer type which is not
3783 automatically displayed as character or string data.
3785 * The /s format now works with the print command. It displays
3786 arrays of single-byte integers and pointers to single-byte integers
3789 * Target descriptions can now describe target-specific registers,
3790 for architectures which have implemented the support (currently
3791 only ARM, M68K, and MIPS).
3793 * GDB and the GDB remote stub, gdbserver, now support the XScale
3796 * The GDB remote stub, gdbserver, has been updated to support
3797 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3798 has been rewritten to use the standard GDB remote protocol.
3800 * GDB can now step into C++ functions which are called through thunks.
3802 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3804 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3805 layout. It also supports a TextSeg= and DataSeg= response when only
3806 segment base addresses (rather than offsets) are available.
3808 * The /i format now outputs any trailing branch delay slot instructions
3809 immediately following the last instruction within the count specified.
3811 * The GDB remote protocol "T" stop reply packet now supports a
3812 "library" response. Combined with the new "qXfer:libraries:read"
3813 packet, this response allows GDB to debug shared libraries on targets
3814 where the operating system manages the list of loaded libraries (e.g.
3815 Windows and SymbianOS).
3817 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3818 (DLLs) on Windows and Windows CE targets.
3820 * GDB now supports a faster verification that a .debug file matches its binary
3821 according to its build-id signature, if the signature is present.
3827 Enable or disable hardware flow control (RTS/CTS) on the serial port
3828 when debugging using remote targets.
3830 set mem inaccessible-by-default
3831 show mem inaccessible-by-default
3832 If the target supplies a memory map, for instance via the remote
3833 protocol's "qXfer:memory-map:read" packet, setting this variable
3834 prevents GDB from accessing memory outside the memory map. This
3835 is useful for targets with memory mapped registers or which react
3836 badly to accesses of unmapped address space.
3838 set breakpoint auto-hw
3839 show breakpoint auto-hw
3840 If the target supplies a memory map, for instance via the remote
3841 protocol's "qXfer:memory-map:read" packet, setting this variable
3842 lets GDB use hardware breakpoints automatically for memory regions
3843 where it can not use software breakpoints. This covers both the
3844 "break" command and internal breakpoints used for other commands
3845 including "next" and "finish".
3848 catch exception unhandled
3849 Stop the program execution when Ada exceptions are raised.
3852 Stop the program execution when an Ada assertion failed.
3856 Set an alternate system root for target files. This is a more
3857 general version of "set solib-absolute-prefix", which is now
3858 an alias to "set sysroot".
3861 Provide extended SPU facility status information. This set of
3862 commands is available only when debugging the Cell/B.E. SPU
3865 * New native configurations
3867 OpenBSD/sh sh*-*openbsd*
3870 unset tdesc filename
3872 Use the specified local file as an XML target description, and do
3873 not query the target for its built-in description.
3877 OpenBSD/sh sh*-*-openbsd*
3878 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3879 Toshiba Media Processor mep-elf
3881 * New remote packets
3884 Ignore the specified signals; pass them directly to the debugged program
3885 without stopping other threads or reporting them to GDB.
3887 qXfer:features:read:
3888 Read an XML target description from the target, which describes its
3893 Read or write contents of an spufs file on the target system. These
3894 packets are available only on the Cell/B.E. SPU architecture.
3896 qXfer:libraries:read:
3897 Report the loaded shared libraries. Combined with new "T" packet
3898 response, this packet allows GDB to debug shared libraries on
3899 targets where the operating system manages the list of loaded
3900 libraries (e.g. Windows and SymbianOS).
3904 Support for these obsolete configurations has been removed.
3912 i[34567]86-*-lynxos*
3913 i[34567]86-*-netware*
3914 i[34567]86-*-sco3.2v5*
3915 i[34567]86-*-sco3.2v4*
3917 i[34567]86-*-sysv4.2*
3920 i[34567]86-*-unixware2*
3921 i[34567]86-*-unixware*
3930 * Other removed features
3937 Various m68k-only ROM monitors.
3944 Various Renesas ROM monitors and debugging interfaces for SH and
3949 Support for a Macraigor serial interface to on-chip debugging.
3950 GDB does not directly support the newer parallel or USB
3955 A debug information format. The predecessor to DWARF 2 and
3956 DWARF 3, which are still supported.
3958 Support for the HP aCC compiler on HP-UX/PA-RISC
3960 SOM-encapsulated symbolic debugging information, automatic
3961 invocation of pxdb, and the aCC custom C++ ABI. This does not
3962 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3963 with aCC can still be debugged on an assembly level.
3965 MIPS ".pdr" sections
3967 A MIPS-specific format used to describe stack frame layout
3968 in debugging information.
3972 GDB could work with an older version of Guile to debug
3973 the interpreter and Scheme programs running in it.
3975 set mips stack-arg-size
3976 set mips saved-gpreg-size
3978 Use "set mips abi" to control parameter passing for MIPS.
3980 *** Changes in GDB 6.6
3985 Cell Broadband Engine SPU spu-elf
3987 * GDB can now be configured as a cross-debugger targeting native Windows
3988 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3989 running on a Windows system over TCP/IP to debug Windows programs.
3991 * The GDB remote stub, gdbserver, has been updated to support Windows and
3992 Cygwin debugging. Both single-threaded and multi-threaded programs are
3995 * The "set trust-readonly-sections" command works again. This command was
3996 broken in GDB 6.3, 6.4, and 6.5.
3998 * The "load" command now supports writing to flash memory, if the remote
3999 stub provides the required support.
4001 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4002 longer requires symbolic debug information (e.g. DWARF-2).
4007 unset substitute-path
4008 show substitute-path
4009 Manage a list of substitution rules that GDB uses to rewrite the name
4010 of the directories where the sources are located. This can be useful
4011 for instance when the sources were moved to a different location
4012 between compilation and debugging.
4016 Print each CLI command as it is executed. Each command is prefixed with
4017 a number of `+' symbols representing the nesting depth.
4018 The source command now has a `-v' option to enable the same feature.
4022 The ARM Demon monitor support (RDP protocol, "target rdp").
4024 Kernel Object Display, an embedded debugging feature which only worked with
4025 an obsolete version of Cisco IOS.
4027 The 'set download-write-size' and 'show download-write-size' commands.
4029 * New remote packets
4032 Tell a stub about GDB client features, and request remote target features.
4033 The first feature implemented is PacketSize, which allows the target to
4034 specify the size of packets it can handle - to minimize the number of
4035 packets required and improve performance when connected to a remote
4039 Fetch an OS auxilliary vector from the remote stub. This packet is a
4040 more efficient replacement for qPart:auxv:read.
4042 qXfer:memory-map:read:
4043 Fetch a memory map from the remote stub, including information about
4044 RAM, ROM, and flash memory devices.
4049 Erase and program a flash memory device.
4051 * Removed remote packets
4054 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4055 used it, and only gdbserver implemented it.
4057 *** Changes in GDB 6.5
4061 Renesas M32C/M16C m32c-elf
4063 Morpho Technologies ms1 ms1-elf
4067 init-if-undefined Initialize a convenience variable, but
4068 only if it doesn't already have a value.
4070 The following commands are presently only implemented for native GNU/Linux:
4072 checkpoint Save a snapshot of the program state.
4074 restart <n> Return the program state to a
4075 previously saved state.
4077 info checkpoints List currently saved checkpoints.
4079 delete-checkpoint <n> Delete a previously saved checkpoint.
4081 set|show detach-on-fork Tell gdb whether to detach from a newly
4082 forked process, or to keep debugging it.
4084 info forks List forks of the user program that
4085 are available to be debugged.
4087 fork <n> Switch to debugging one of several
4088 forks of the user program that are
4089 available to be debugged.
4091 delete-fork <n> Delete a fork from the list of forks
4092 that are available to be debugged (and
4093 kill the forked process).
4095 detach-fork <n> Delete a fork from the list of forks
4096 that are available to be debugged (and
4097 allow the process to continue).
4101 Morpho Technologies ms2 ms1-elf
4103 * Improved Windows host support
4105 GDB now builds as a cross debugger hosted on i686-mingw32, including
4106 native console support, and remote communications using either
4107 network sockets or serial ports.
4109 * Improved Modula-2 language support
4111 GDB can now print most types in the Modula-2 syntax. This includes:
4112 basic types, set types, record types, enumerated types, range types,
4113 pointer types and ARRAY types. Procedure var parameters are correctly
4114 printed and hexadecimal addresses and character constants are also
4115 written in the Modula-2 syntax. Best results can be obtained by using
4116 GNU Modula-2 together with the -gdwarf-2 command line option.
4120 The ARM rdi-share module.
4122 The Netware NLM debug server.
4124 *** Changes in GDB 6.4
4126 * New native configurations
4128 OpenBSD/arm arm*-*-openbsd*
4129 OpenBSD/mips64 mips64-*-openbsd*
4133 Morpho Technologies ms1 ms1-elf
4135 * New command line options
4137 --batch-silent As for --batch, but totally silent.
4138 --return-child-result The debugger will exist with the same value
4139 the child (debugged) program exited with.
4140 --eval-command COMMAND, -ex COMMAND
4141 Execute a single GDB CLI command. This may be
4142 specified multiple times and in conjunction
4143 with the --command (-x) option.
4145 * Deprecated commands removed
4147 The following commands, that were deprecated in 2000, have been
4151 set|show arm disassembly-flavor set|show arm disassembler
4152 othernames set arm disassembler
4153 set|show remotedebug set|show debug remote
4154 set|show archdebug set|show debug arch
4155 set|show eventdebug set|show debug event
4158 * New BSD user-level threads support
4160 It is now possible to debug programs using the user-level threads
4161 library on OpenBSD and FreeBSD. Currently supported (target)
4164 FreeBSD/amd64 x86_64-*-freebsd*
4165 FreeBSD/i386 i386-*-freebsd*
4166 OpenBSD/i386 i386-*-openbsd*
4168 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4169 are not yet supported.
4171 * New support for Matsushita MN10300 w/sim added
4172 (Work in progress). mn10300-elf.
4174 * REMOVED configurations and files
4176 VxWorks and the XDR protocol *-*-vxworks
4177 Motorola MCORE mcore-*-*
4178 National Semiconductor NS32000 ns32k-*-*
4180 * New "set print array-indexes" command
4182 After turning this setting "on", GDB prints the index of each element
4183 when displaying arrays. The default is "off" to preserve the previous
4186 * VAX floating point support
4188 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4190 * User-defined command support
4192 In addition to using $arg0..$arg9 for argument passing, it is now possible
4193 to use $argc to determine now many arguments have been passed. See the
4194 section on user-defined commands in the user manual for more information.
4196 *** Changes in GDB 6.3:
4198 * New command line option
4200 GDB now accepts -l followed by a number to set the timeout for remote
4203 * GDB works with GCC -feliminate-dwarf2-dups
4205 GDB now supports a more compact representation of DWARF-2 debug
4206 information using DW_FORM_ref_addr references. These are produced
4207 by GCC with the option -feliminate-dwarf2-dups and also by some
4208 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4209 to use -feliminate-dwarf2-dups.
4211 * Internationalization
4213 When supported by the host system, GDB will be built with
4214 internationalization (libintl). The task of marking up the sources is
4215 continued, we're looking forward to our first translation.
4219 Initial support for debugging programs compiled with the GNAT
4220 implementation of the Ada programming language has been integrated
4221 into GDB. In this release, support is limited to expression evaluation.
4223 * New native configurations
4225 GNU/Linux/m32r m32r-*-linux-gnu
4229 GDB's remote protocol now includes support for the 'p' packet. This
4230 packet is used to fetch individual registers from a remote inferior.
4232 * END-OF-LIFE registers[] compatibility module
4234 GDB's internal register infrastructure has been completely rewritten.
4235 The new infrastructure making possible the implementation of key new
4236 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4239 GDB 6.3 will be the last release to include the the registers[]
4240 compatibility module that allowed out-of-date configurations to
4241 continue to work. This change directly impacts the following
4251 powerpc bdm protocol
4253 Unless there is activity to revive these configurations, they will be
4254 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4256 * OBSOLETE configurations and files
4258 Configurations that have been declared obsolete in this release have
4259 been commented out. Unless there is activity to revive these
4260 configurations, the next release of GDB will have their sources
4261 permanently REMOVED.
4270 *** Changes in GDB 6.2.1:
4272 * MIPS `break main; run' gave an heuristic-fence-post warning
4274 When attempting to run even a simple program, a warning about
4275 heuristic-fence-post being hit would be reported. This problem has
4278 * MIPS IRIX 'long double' crashed GDB
4280 When examining a long double variable, GDB would get a segmentation
4281 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4282 IRIX long double values).
4286 A bug in the VAX stack code was causing problems with the "next"
4287 command. This problem has been fixed.
4289 *** Changes in GDB 6.2:
4291 * Fix for ``many threads''
4293 On GNU/Linux systems that use the NPTL threads library, a program
4294 rapidly creating and deleting threads would confuse GDB leading to the
4297 ptrace: No such process.
4298 thread_db_get_info: cannot get thread info: generic error
4300 This problem has been fixed.
4302 * "-async" and "-noasync" options removed.
4304 Support for the broken "-noasync" option has been removed (it caused
4307 * New ``start'' command.
4309 This command runs the program until the begining of the main procedure.
4311 * New BSD Kernel Data Access Library (libkvm) interface
4313 Using ``target kvm'' it is now possible to debug kernel core dumps and
4314 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4315 platforms. Currently supported (native-only) configurations are:
4317 FreeBSD/amd64 x86_64-*-freebsd*
4318 FreeBSD/i386 i?86-*-freebsd*
4319 NetBSD/i386 i?86-*-netbsd*
4320 NetBSD/m68k m68*-*-netbsd*
4321 NetBSD/sparc sparc-*-netbsd*
4322 OpenBSD/amd64 x86_64-*-openbsd*
4323 OpenBSD/i386 i?86-*-openbsd*
4324 OpenBSD/m68k m68*-openbsd*
4325 OpenBSD/sparc sparc-*-openbsd*
4327 * Signal trampoline code overhauled
4329 Many generic problems with GDB's signal handling code have been fixed.
4330 These include: backtraces through non-contiguous stacks; recognition
4331 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4332 call; backtrace through a signal trampoline; step into and out of
4333 signal handlers; and single-stepping in the signal trampoline.
4335 Please note that kernel bugs are a limiting factor here. These
4336 features have been shown to work on an s390 GNU/Linux system that
4337 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4339 * Cygwin support for DWARF 2 added.
4341 * New native configurations
4343 GNU/Linux/hppa hppa*-*-linux*
4344 OpenBSD/hppa hppa*-*-openbsd*
4345 OpenBSD/m68k m68*-*-openbsd*
4346 OpenBSD/m88k m88*-*-openbsd*
4347 OpenBSD/powerpc powerpc-*-openbsd*
4348 NetBSD/vax vax-*-netbsd*
4349 OpenBSD/vax vax-*-openbsd*
4351 * END-OF-LIFE frame compatibility module
4353 GDB's internal frame infrastructure has been completely rewritten.
4354 The new infrastructure making it possible to support key new features
4355 including DWARF 2 Call Frame Information. To aid in the task of
4356 migrating old configurations to this new infrastructure, a
4357 compatibility module, that allowed old configurations to continue to
4358 work, was also included.
4360 GDB 6.2 will be the last release to include this frame compatibility
4361 module. This change directly impacts the following configurations:
4371 Unless there is activity to revive these configurations, they will be
4372 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4374 * REMOVED configurations and files
4376 Sun 3, running SunOS 3 m68*-*-sunos3*
4377 Sun 3, running SunOS 4 m68*-*-sunos4*
4378 Sun 2, running SunOS 3 m68000-*-sunos3*
4379 Sun 2, running SunOS 4 m68000-*-sunos4*
4380 Motorola 680x0 running LynxOS m68*-*-lynxos*
4381 AT&T 3b1/Unix pc m68*-att-*
4382 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4383 decstation mips-dec-* mips-little-*
4384 riscos mips-*-riscos* mips-*-sysv*
4385 sonymips mips-sony-*
4386 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4388 *** Changes in GDB 6.1.1:
4390 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4392 The TUI (Text-mode User Interface) is now built as part of a default
4393 GDB configuration. It is enabled by either selecting the TUI with the
4394 command line option "-i=tui" or by running the separate "gdbtui"
4395 program. For more information on the TUI, see the manual "Debugging
4398 * Pending breakpoint support (also included in GDB 6.1)
4400 Support has been added to allow you to specify breakpoints in shared
4401 libraries that have not yet been loaded. If a breakpoint location
4402 cannot be found, and the "breakpoint pending" option is set to auto,
4403 GDB queries you if you wish to make the breakpoint pending on a future
4404 shared-library load. If and when GDB resolves the breakpoint symbol,
4405 the pending breakpoint is removed as one or more regular breakpoints
4408 Pending breakpoints are very useful for GCJ Java debugging.
4410 * Fixed ISO-C build problems
4412 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4413 non ISO-C code that stopped them being built using a more strict ISO-C
4414 compiler (e.g., IBM's C compiler).
4416 * Fixed build problem on IRIX 5
4418 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4419 wasn't able to compile compile on an IRIX 5 system.
4421 * Added execute permission to gdb/gdbserver/configure
4423 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4424 permission. This bug would cause configure to fail on a number of
4425 systems (Solaris, IRIX). Ref: server/519.
4427 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4429 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4430 has been updated to use constant array sizes.
4432 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4434 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4435 its generated DWARF Call Frame Info. This encoding was causing GDB to
4436 panic, that panic has been fixed. Ref: gdb/1628.
4438 * Fixed a problem when examining parameters in shared library code.
4440 When examining parameters in optimized shared library code generated
4441 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4442 not available''. GDB now correctly displays the variable's value.
4444 *** Changes in GDB 6.1:
4446 * Removed --with-mmalloc
4448 Support for the mmalloc memory manager has been removed, as it
4449 conflicted with the internal gdb byte cache.
4451 * Changes in AMD64 configurations
4453 The AMD64 target now includes the %cs and %ss registers. As a result
4454 the AMD64 remote protocol has changed; this affects the floating-point
4455 and SSE registers. If you rely on those registers for your debugging,
4456 you should upgrade gdbserver on the remote side.
4458 * Revised SPARC target
4460 The SPARC target has been completely revised, incorporating the
4461 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4462 support for LynxOS and SunOS 4 has been dropped. Calling functions
4463 from within GDB on operating systems with a non-executable stack
4464 (Solaris, OpenBSD) now works.
4468 GDB has a new C++ demangler which does a better job on the mangled
4469 names generated by current versions of g++. It also runs faster, so
4470 with this and other changes gdb should now start faster on large C++
4473 * DWARF 2 Location Expressions
4475 GDB support for location expressions has been extended to support function
4476 arguments and frame bases. Older versions of GDB could crash when they
4479 * C++ nested types and namespaces
4481 GDB's support for nested types and namespaces in C++ has been
4482 improved, especially if you use the DWARF 2 debugging format. (This
4483 is the default for recent versions of GCC on most platforms.)
4484 Specifically, if you have a class "Inner" defined within a class or
4485 namespace "Outer", then GDB realizes that the class's name is
4486 "Outer::Inner", not simply "Inner". This should greatly reduce the
4487 frequency of complaints about not finding RTTI symbols. In addition,
4488 if you are stopped at inside of a function defined within a namespace,
4489 GDB modifies its name lookup accordingly.
4491 * New native configurations
4493 NetBSD/amd64 x86_64-*-netbsd*
4494 OpenBSD/amd64 x86_64-*-openbsd*
4495 OpenBSD/alpha alpha*-*-openbsd*
4496 OpenBSD/sparc sparc-*-openbsd*
4497 OpenBSD/sparc64 sparc64-*-openbsd*
4499 * New debugging protocols
4501 M32R with SDI protocol m32r-*-elf*
4503 * "set prompt-escape-char" command deleted.
4505 The command "set prompt-escape-char" has been deleted. This command,
4506 and its very obscure effet on GDB's prompt, was never documented,
4507 tested, nor mentioned in the NEWS file.
4509 * OBSOLETE configurations and files
4511 Configurations that have been declared obsolete in this release have
4512 been commented out. Unless there is activity to revive these
4513 configurations, the next release of GDB will have their sources
4514 permanently REMOVED.
4516 Sun 3, running SunOS 3 m68*-*-sunos3*
4517 Sun 3, running SunOS 4 m68*-*-sunos4*
4518 Sun 2, running SunOS 3 m68000-*-sunos3*
4519 Sun 2, running SunOS 4 m68000-*-sunos4*
4520 Motorola 680x0 running LynxOS m68*-*-lynxos*
4521 AT&T 3b1/Unix pc m68*-att-*
4522 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4523 decstation mips-dec-* mips-little-*
4524 riscos mips-*-riscos* mips-*-sysv*
4525 sonymips mips-sony-*
4526 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4528 * REMOVED configurations and files
4530 SGI Irix-4.x mips-sgi-irix4 or iris4
4531 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4532 Z8000 simulator z8k-zilog-none or z8ksim
4533 Matsushita MN10200 w/simulator mn10200-*-*
4534 H8/500 simulator h8500-hitachi-hms or h8500hms
4535 HP/PA running BSD hppa*-*-bsd*
4536 HP/PA running OSF/1 hppa*-*-osf*
4537 HP/PA Pro target hppa*-*-pro*
4538 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4539 386BSD i[3456]86-*-bsd*
4540 Sequent family i[3456]86-sequent-sysv4*
4541 i[3456]86-sequent-sysv*
4542 i[3456]86-sequent-bsd*
4543 SPARC running LynxOS sparc-*-lynxos*
4544 SPARC running SunOS 4 sparc-*-sunos4*
4545 Tsqware Sparclet sparclet-*-*
4546 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4548 *** Changes in GDB 6.0:
4552 Support for debugging the Objective-C programming language has been
4553 integrated into GDB.
4555 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4557 DWARF 2's Call Frame Information makes available compiler generated
4558 information that more exactly describes the program's run-time stack.
4559 By using this information, GDB is able to provide more robust stack
4562 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4563 have been updated to use a new backtrace mechanism which includes
4564 DWARF 2 CFI support.
4568 GDB's remote protocol has been extended to include support for hosted
4569 file I/O (where the remote target uses GDB's file system). See GDB's
4570 remote protocol documentation for details.
4572 * All targets using the new architecture framework.
4574 All of GDB's targets have been updated to use the new internal
4575 architecture framework. The way is now open for future GDB releases
4576 to include cross-architecture native debugging support (i386 on amd64,
4579 * GNU/Linux's Thread Local Storage (TLS)
4581 GDB now includes support for for the GNU/Linux implementation of
4582 per-thread variables.
4584 * GNU/Linux's Native POSIX Thread Library (NPTL)
4586 GDB's thread code has been updated to work with either the new
4587 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4589 * Separate debug info.
4591 GDB, in conjunction with BINUTILS, now supports a mechanism for
4592 automatically loading debug information from a separate file. Instead
4593 of shipping full debug and non-debug versions of system libraries,
4594 system integrators can now instead ship just the stripped libraries
4595 and optional debug files.
4597 * DWARF 2 Location Expressions
4599 DWARF 2 Location Expressions allow the compiler to more completely
4600 describe the location of variables (even in optimized code) to the
4603 GDB now includes preliminary support for location expressions (support
4604 for DW_OP_piece is still missing).
4608 A number of long standing bugs that caused GDB to die while starting a
4609 Java application have been fixed. GDB's Java support is now
4610 considered "useable".
4612 * GNU/Linux support for fork, vfork, and exec.
4614 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4615 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4618 * GDB supports logging output to a file
4620 There are two new commands, "set logging" and "show logging", which can be
4621 used to capture GDB's output to a file.
4623 * The meaning of "detach" has changed for gdbserver
4625 The "detach" command will now resume the application, as documented. To
4626 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4629 * d10v, m68hc11 `regs' command deprecated
4631 The `info registers' command has been updated so that it displays the
4632 registers using a format identical to the old `regs' command.
4636 A new command, "maint set profile on/off", has been added. This command can
4637 be used to enable or disable profiling while running GDB, to profile a
4638 session or a set of commands. In addition there is a new configure switch,
4639 "--enable-profiling", which will cause GDB to be compiled with profiling
4640 data, for more informative profiling results.
4642 * Default MI syntax changed to "mi2".
4644 The default MI (machine interface) syntax, enabled by the command line
4645 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4646 "mi1", can be enabled by specifying the option "-i=mi1".
4648 Support for the original "mi0" syntax (included in GDB 5.0) has been
4651 Fix for gdb/192: removed extraneous space when displaying frame level.
4652 Fix for gdb/672: update changelist is now output in mi list format.
4653 Fix for gdb/702: a -var-assign that updates the value now shows up
4654 in a subsequent -var-update.
4656 * New native configurations.
4658 FreeBSD/amd64 x86_64-*-freebsd*
4660 * Multi-arched targets.
4662 HP/PA HPUX11 hppa*-*-hpux*
4663 Renesas M32R/D w/simulator m32r-*-elf*
4665 * OBSOLETE configurations and files
4667 Configurations that have been declared obsolete in this release have
4668 been commented out. Unless there is activity to revive these
4669 configurations, the next release of GDB will have their sources
4670 permanently REMOVED.
4672 Z8000 simulator z8k-zilog-none or z8ksim
4673 Matsushita MN10200 w/simulator mn10200-*-*
4674 H8/500 simulator h8500-hitachi-hms or h8500hms
4675 HP/PA running BSD hppa*-*-bsd*
4676 HP/PA running OSF/1 hppa*-*-osf*
4677 HP/PA Pro target hppa*-*-pro*
4678 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4679 Sequent family i[3456]86-sequent-sysv4*
4680 i[3456]86-sequent-sysv*
4681 i[3456]86-sequent-bsd*
4682 Tsqware Sparclet sparclet-*-*
4683 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4685 * REMOVED configurations and files
4688 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4689 IBM AIX PS/2 i[3456]86-*-aix
4690 i386 running Mach 3.0 i[3456]86-*-mach3*
4691 i386 running Mach i[3456]86-*-mach*
4692 i386 running OSF/1 i[3456]86-*osf1mk*
4693 HP/Apollo 68k Family m68*-apollo*-sysv*,
4695 m68*-hp-bsd*, m68*-hp-hpux*
4696 Argonaut Risc Chip (ARC) arc-*-*
4697 Mitsubishi D30V d30v-*-*
4698 Fujitsu FR30 fr30-*-elf*
4699 OS/9000 i[34]86-*-os9k
4700 I960 with MON960 i960-*-coff
4702 * MIPS $fp behavior changed
4704 The convenience variable $fp, for the MIPS, now consistently returns
4705 the address of the current frame's base. Previously, depending on the
4706 context, $fp could refer to either $sp or the current frame's base
4707 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4708 The GNU Source-Level Debugger''.
4710 *** Changes in GDB 5.3:
4712 * GNU/Linux shared library multi-threaded performance improved.
4714 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4715 `/proc', in preference to `ptrace' for memory reads. This may result
4716 in an improvement in the start-up time of multi-threaded, shared
4717 library applications when run under GDB. One GDB user writes: ``loads
4718 shared libs like mad''.
4720 * ``gdbserver'' now supports multi-threaded applications on some targets
4722 Support for debugging multi-threaded applications which use
4723 the GNU/Linux LinuxThreads package has been added for
4724 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4725 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4727 * GDB now supports C/C++ preprocessor macros.
4729 GDB now expands preprocessor macro invocations in C/C++ expressions,
4730 and provides various commands for showing macro definitions and how
4733 The new command `macro expand EXPRESSION' expands any macro
4734 invocations in expression, and shows the result.
4736 The new command `show macro MACRO-NAME' shows the definition of the
4737 macro named MACRO-NAME, and where it was defined.
4739 Most compilers don't include information about macros in the debugging
4740 information by default. In GCC 3.1, for example, you need to compile
4741 your program with the options `-gdwarf-2 -g3'. If the macro
4742 information is present in the executable, GDB will read it.
4744 * Multi-arched targets.
4746 DEC Alpha (partial) alpha*-*-*
4747 DEC VAX (partial) vax-*-*
4749 National Semiconductor NS32000 (partial) ns32k-*-*
4750 Motorola 68000 (partial) m68k-*-*
4751 Motorola MCORE mcore-*-*
4755 Fujitsu FRV architecture added by Red Hat frv*-*-*
4758 * New native configurations
4760 Alpha NetBSD alpha*-*-netbsd*
4761 SH NetBSD sh*-*-netbsdelf*
4762 MIPS NetBSD mips*-*-netbsd*
4763 UltraSPARC NetBSD sparc64-*-netbsd*
4765 * OBSOLETE configurations and files
4767 Configurations that have been declared obsolete in this release have
4768 been commented out. Unless there is activity to revive these
4769 configurations, the next release of GDB will have their sources
4770 permanently REMOVED.
4772 Mitsubishi D30V d30v-*-*
4773 OS/9000 i[34]86-*-os9k
4774 IBM AIX PS/2 i[3456]86-*-aix
4775 Fujitsu FR30 fr30-*-elf*
4776 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4777 Argonaut Risc Chip (ARC) arc-*-*
4778 i386 running Mach 3.0 i[3456]86-*-mach3*
4779 i386 running Mach i[3456]86-*-mach*
4780 i386 running OSF/1 i[3456]86-*osf1mk*
4781 HP/Apollo 68k Family m68*-apollo*-sysv*,
4783 m68*-hp-bsd*, m68*-hp-hpux*
4784 I960 with MON960 i960-*-coff
4786 * OBSOLETE languages
4788 CHILL, a Pascal like language used by telecommunications companies.
4790 * REMOVED configurations and files
4792 AMD 29k family via UDI a29k-amd-udi, udi29k
4793 A29K VxWorks a29k-*-vxworks
4794 AMD 29000 embedded, using EBMON a29k-none-none
4795 AMD 29000 embedded with COFF a29k-none-coff
4796 AMD 29000 embedded with a.out a29k-none-aout
4798 testsuite/gdb.hp/gdb.threads-hp/ directory
4800 * New command "set max-user-call-depth <nnn>"
4802 This command allows the user to limit the call depth of user-defined
4803 commands. The default is 1024.
4805 * Changes in FreeBSD/i386 native debugging.
4807 Support for the "generate-core-file" has been added.
4809 * New commands "dump", "append", and "restore".
4811 These commands allow data to be copied from target memory
4812 to a bfd-format or binary file (dump and append), and back
4813 from a file into memory (restore).
4815 * Improved "next/step" support on multi-processor Alpha Tru64.
4817 The previous single-step mechanism could cause unpredictable problems,
4818 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4819 of a software single-step mechanism prevents this.
4821 *** Changes in GDB 5.2.1:
4829 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4830 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4831 Fix, by Joel Brobecker imported from mainline.
4833 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4834 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4835 Fix, by Fred Fish, imported from mainline.
4837 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4838 Surprisingly enough, it works now.
4839 By Michal Ludvig, imported from mainline.
4841 i386 hardware watchpoint support:
4842 avoid misses on second run for some targets.
4843 By Pierre Muller, imported from mainline.
4845 *** Changes in GDB 5.2:
4847 * New command "set trust-readonly-sections on[off]".
4849 This command is a hint that tells gdb that read-only sections
4850 really are read-only (ie. that their contents will not change).
4851 In this mode, gdb will go to the object file rather than the
4852 target to read memory from read-only sections (such as ".text").
4853 This can be a significant performance improvement on some
4854 (notably embedded) targets.
4856 * New command "generate-core-file" (or "gcore").
4858 This new gdb command allows the user to drop a core file of the child
4859 process state at any time. So far it's been implemented only for
4860 GNU/Linux and Solaris, but should be relatively easily ported to other
4861 hosts. Argument is core file name (defaults to core.<pid>).
4863 * New command line option
4865 GDB now accepts --pid or -p followed by a process id.
4867 * Change in command line behavior -- corefiles vs. process ids.
4869 There is a subtle behavior in the way in which GDB handles
4870 command line arguments. The first non-flag argument is always
4871 a program to debug, but the second non-flag argument may either
4872 be a corefile or a process id. Previously, GDB would attempt to
4873 open the second argument as a corefile, and if that failed, would
4874 issue a superfluous error message and then attempt to attach it as
4875 a process. Now, if the second argument begins with a non-digit,
4876 it will be treated as a corefile. If it begins with a digit,
4877 GDB will attempt to attach it as a process, and if no such process
4878 is found, will then attempt to open it as a corefile.
4880 * Changes in ARM configurations.
4882 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4883 configuration is fully multi-arch.
4885 * New native configurations
4887 ARM NetBSD arm*-*-netbsd*
4888 x86 OpenBSD i[3456]86-*-openbsd*
4889 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4890 Sparc64 running FreeBSD sparc64-*-freebsd*
4894 Sanyo XStormy16 xstormy16-elf
4896 * OBSOLETE configurations and files
4898 Configurations that have been declared obsolete in this release have
4899 been commented out. Unless there is activity to revive these
4900 configurations, the next release of GDB will have their sources
4901 permanently REMOVED.
4903 AMD 29k family via UDI a29k-amd-udi, udi29k
4904 A29K VxWorks a29k-*-vxworks
4905 AMD 29000 embedded, using EBMON a29k-none-none
4906 AMD 29000 embedded with COFF a29k-none-coff
4907 AMD 29000 embedded with a.out a29k-none-aout
4909 testsuite/gdb.hp/gdb.threads-hp/ directory
4911 * REMOVED configurations and files
4913 TI TMS320C80 tic80-*-*
4915 PowerPC Solaris powerpcle-*-solaris*
4916 PowerPC Windows NT powerpcle-*-cygwin32
4917 PowerPC Netware powerpc-*-netware*
4918 Harris/CXUX m88k m88*-harris-cxux*
4919 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4920 ns32k-utek-sysv* ns32k-utek-*
4921 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4922 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4923 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4924 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4925 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4927 * Changes to command line processing
4929 The new `--args' feature can be used to specify command-line arguments
4930 for the inferior from gdb's command line.
4932 * Changes to key bindings
4934 There is a new `operate-and-get-next' function bound to `C-o'.
4936 *** Changes in GDB 5.1.1
4938 Fix compile problem on DJGPP.
4940 Fix a problem with floating-point registers on the i386 being
4943 Fix to stop GDB crashing on .debug_str debug info.
4945 Numerous documentation fixes.
4947 Numerous testsuite fixes.
4949 *** Changes in GDB 5.1:
4951 * New native configurations
4953 Alpha FreeBSD alpha*-*-freebsd*
4954 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4955 MIPS GNU/Linux mips*-*-linux*
4956 MIPS SGI Irix 6.x mips*-sgi-irix6*
4957 ia64 AIX ia64-*-aix*
4958 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4962 Motorola 68HC11 and 68HC12 m68hc11-elf
4964 UltraSparc running GNU/Linux sparc64-*-linux*
4966 * OBSOLETE configurations and files
4968 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4969 Harris/CXUX m88k m88*-harris-cxux*
4970 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4971 ns32k-utek-sysv* ns32k-utek-*
4972 TI TMS320C80 tic80-*-*
4974 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4975 PowerPC Solaris powerpcle-*-solaris*
4976 PowerPC Windows NT powerpcle-*-cygwin32
4977 PowerPC Netware powerpc-*-netware*
4978 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4979 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4980 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4981 Apple Macintosh (MPW) host N/A
4983 stuff.c (Program to stuff files into a specially prepared space in kdb)
4984 kdb-start.c (Main loop for the standalone kernel debugger)
4986 Configurations that have been declared obsolete in this release have
4987 been commented out. Unless there is activity to revive these
4988 configurations, the next release of GDB will have their sources
4989 permanently REMOVED.
4991 * REMOVED configurations and files
4993 Altos 3068 m68*-altos-*
4994 Convex c1-*-*, c2-*-*
4996 ARM RISCix arm-*-* (as host)
5000 * GDB has been converted to ISO C.
5002 GDB's source code has been converted to ISO C. In particular, the
5003 sources are fully protoized, and rely on standard headers being
5008 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5010 * The MI enabled by default.
5012 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5013 revised and enabled by default. Packages which use GDB as a debugging
5014 engine behind a UI or another front end are encouraged to switch to
5015 using the GDB/MI interface, instead of the old annotations interface
5016 which is now deprecated.
5018 * Support for debugging Pascal programs.
5020 GDB now includes support for debugging Pascal programs. The following
5021 main features are supported:
5023 - Pascal-specific data types such as sets;
5025 - automatic recognition of Pascal sources based on file-name
5028 - Pascal-style display of data types, variables, and functions;
5030 - a Pascal expression parser.
5032 However, some important features are not yet supported.
5034 - Pascal string operations are not supported at all;
5036 - there are some problems with boolean types;
5038 - Pascal type hexadecimal constants are not supported
5039 because they conflict with the internal variables format;
5041 - support for Pascal objects and classes is not full yet;
5043 - unlike Pascal, GDB is case-sensitive for symbol names.
5045 * Changes in completion.
5047 Commands such as `shell', `run' and `set args', which pass arguments
5048 to inferior programs, now complete on file names, similar to what
5049 users expect at the shell prompt.
5051 Commands which accept locations, such as `disassemble', `print',
5052 `breakpoint', `until', etc. now complete on filenames as well as
5053 program symbols. Thus, if you type "break foob TAB", and the source
5054 files linked into the programs include `foobar.c', that file name will
5055 be one of the candidates for completion. However, file names are not
5056 considered for completion after you typed a colon that delimits a file
5057 name from a name of a function in that file, as in "break foo.c:bar".
5059 `set demangle-style' completes on available demangling styles.
5061 * New platform-independent commands:
5063 It is now possible to define a post-hook for a command as well as a
5064 hook that runs before the command. For more details, see the
5065 documentation of `hookpost' in the GDB manual.
5067 * Changes in GNU/Linux native debugging.
5069 Support for debugging multi-threaded programs has been completely
5070 revised for all platforms except m68k and sparc. You can now debug as
5071 many threads as your system allows you to have.
5073 Attach/detach is supported for multi-threaded programs.
5075 Support for SSE registers was added for x86. This doesn't work for
5076 multi-threaded programs though.
5078 * Changes in MIPS configurations.
5080 Multi-arch support is enabled for all MIPS configurations.
5082 GDB can now be built as native debugger on SGI Irix 6.x systems for
5083 debugging n32 executables. (Debugging 64-bit executables is not yet
5086 * Unified support for hardware watchpoints in all x86 configurations.
5088 Most (if not all) native x86 configurations support hardware-assisted
5089 breakpoints and watchpoints in a unified manner. This support
5090 implements debug register sharing between watchpoints, which allows to
5091 put a virtually infinite number of watchpoints on the same address,
5092 and also supports watching regions up to 16 bytes with several debug
5095 The new maintenance command `maintenance show-debug-regs' toggles
5096 debugging print-outs in functions that insert, remove, and test
5097 watchpoints and hardware breakpoints.
5099 * Changes in the DJGPP native configuration.
5101 New command ``info dos sysinfo'' displays assorted information about
5102 the CPU, OS, memory, and DPMI server.
5104 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5105 display information about segment descriptors stored in GDT, LDT, and
5108 New commands ``info dos pde'' and ``info dos pte'' display entries
5109 from Page Directory and Page Tables (for now works with CWSDPMI only).
5110 New command ``info dos address-pte'' displays the Page Table entry for
5111 a given linear address.
5113 GDB can now pass command lines longer than 126 characters to the
5114 program being debugged (requires an update to the libdbg.a library
5115 which is part of the DJGPP development kit).
5117 DWARF2 debug info is now supported.
5119 It is now possible to `step' and `next' through calls to `longjmp'.
5121 * Changes in documentation.
5123 All GDB documentation was converted to GFDL, the GNU Free
5124 Documentation License.
5126 Tracepoints-related commands are now fully documented in the GDB
5129 TUI, the Text-mode User Interface, is now documented in the manual.
5131 Tracepoints-related commands are now fully documented in the GDB
5134 The "GDB Internals" manual now has an index. It also includes
5135 documentation of `ui_out' functions, GDB coding standards, x86
5136 hardware watchpoints, and memory region attributes.
5138 * GDB's version number moved to ``version.in''
5140 The Makefile variable VERSION has been replaced by the file
5141 ``version.in''. People creating GDB distributions should update the
5142 contents of this file.
5146 GUD support is now a standard part of the EMACS distribution.
5148 *** Changes in GDB 5.0:
5150 * Improved support for debugging FP programs on x86 targets
5152 Unified and much-improved support for debugging floating-point
5153 programs on all x86 targets. In particular, ``info float'' now
5154 displays the FP registers in the same format on all x86 targets, with
5155 greater level of detail.
5157 * Improvements and bugfixes in hardware-assisted watchpoints
5159 It is now possible to watch array elements, struct members, and
5160 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5161 on x86 targets no longer erroneously trigger when the address is
5164 * Improvements in the native DJGPP version of GDB
5166 The distribution now includes all the scripts and auxiliary files
5167 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5168 machines ``out of the box''.
5170 The DJGPP version can now debug programs that use signals. It is
5171 possible to catch signals that happened in the debuggee, deliver
5172 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5173 would kill the program being debugged.) Programs that hook hardware
5174 interrupts (keyboard, timer, etc.) can also be debugged.
5176 It is now possible to debug DJGPP programs that redirect their
5177 standard handles or switch them to raw (as opposed to cooked) mode, or
5178 even close them. The command ``run < foo > bar'' works as expected,
5179 and ``info terminal'' reports useful information about the debuggee's
5180 terminal, including raw/cooked mode, redirection, etc.
5182 The DJGPP version now uses termios functions for console I/O, which
5183 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5186 DOS-style file names with drive letters are now fully supported by
5189 It is now possible to debug DJGPP programs that switch their working
5190 directory. It is also possible to rerun the debuggee any number of
5191 times without restarting GDB; thus, you can use the same setup,
5192 breakpoints, etc. for many debugging sessions.
5194 * New native configurations
5196 ARM GNU/Linux arm*-*-linux*
5197 PowerPC GNU/Linux powerpc-*-linux*
5201 Motorola MCore mcore-*-*
5202 x86 VxWorks i[3456]86-*-vxworks*
5203 PowerPC VxWorks powerpc-*-vxworks*
5204 TI TMS320C80 tic80-*-*
5206 * OBSOLETE configurations
5208 Altos 3068 m68*-altos-*
5209 Convex c1-*-*, c2-*-*
5211 ARM RISCix arm-*-* (as host)
5214 Configurations that have been declared obsolete will be commented out,
5215 but the code will be left in place. If there is no activity to revive
5216 these configurations before the next release of GDB, the sources will
5217 be permanently REMOVED.
5219 * Gould support removed
5221 Support for the Gould PowerNode and NP1 has been removed.
5223 * New features for SVR4
5225 On SVR4 native platforms (such as Solaris), if you attach to a process
5226 without first loading a symbol file, GDB will now attempt to locate and
5227 load symbols from the running process's executable file.
5229 * Many C++ enhancements
5231 C++ support has been greatly improved. Overload resolution now works properly
5232 in almost all cases. RTTI support is on the way.
5234 * Remote targets can connect to a sub-program
5236 A popen(3) style serial-device has been added. This device starts a
5237 sub-process (such as a stand-alone simulator) and then communicates
5238 with that. The sub-program to run is specified using the syntax
5239 ``|<program> <args>'' vis:
5241 (gdb) set remotedebug 1
5242 (gdb) target extended-remote |mn10300-elf-sim program-args
5244 * MIPS 64 remote protocol
5246 A long standing bug in the mips64 remote protocol where by GDB
5247 expected certain 32 bit registers (ex SR) to be transfered as 32
5248 instead of 64 bits has been fixed.
5250 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5251 added to provide backward compatibility with older versions of GDB.
5253 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5255 The command ``set remotebinarydownload'' command has been replaced by
5256 ``set remote X-packet''. Other commands in ``set remote'' family
5257 include ``set remote P-packet''.
5259 * Breakpoint commands accept ranges.
5261 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5262 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5263 ``tracepoint passcount'' also accepts a range of tracepoints.
5265 * ``apropos'' command added.
5267 The ``apropos'' command searches through command names and
5268 documentation strings, printing out matches, making it much easier to
5269 try to find a command that does what you are looking for.
5273 A new machine oriented interface (MI) has been added to GDB. This
5274 interface is designed for debug environments running GDB as a separate
5275 process. This is part of the long term libGDB project. See the
5276 "GDB/MI" chapter of the GDB manual for further information. It can be
5277 enabled by configuring with:
5279 .../configure --enable-gdbmi
5281 *** Changes in GDB-4.18:
5283 * New native configurations
5285 HP-UX 10.20 hppa*-*-hpux10.20
5286 HP-UX 11.x hppa*-*-hpux11.0*
5287 M68K GNU/Linux m68*-*-linux*
5291 Fujitsu FR30 fr30-*-elf*
5292 Intel StrongARM strongarm-*-*
5293 Mitsubishi D30V d30v-*-*
5295 * OBSOLETE configurations
5297 Gould PowerNode, NP1 np1-*-*, pn-*-*
5299 Configurations that have been declared obsolete will be commented out,
5300 but the code will be left in place. If there is no activity to revive
5301 these configurations before the next release of GDB, the sources will
5302 be permanently REMOVED.
5306 As a compatibility experiment, GDB's source files buildsym.h and
5307 buildsym.c have been converted to pure standard C, no longer
5308 containing any K&R compatibility code. We believe that all systems in
5309 use today either come with a standard C compiler, or have a GCC port
5310 available. If this is not true, please report the affected
5311 configuration to bug-gdb@gnu.org immediately. See the README file for
5312 information about getting a standard C compiler if you don't have one
5317 GDB now uses readline 2.2.
5319 * set extension-language
5321 You can now control the mapping between filename extensions and source
5322 languages by using the `set extension-language' command. For instance,
5323 you can ask GDB to treat .c files as C++ by saying
5324 set extension-language .c c++
5325 The command `info extensions' lists all of the recognized extensions
5326 and their associated languages.
5328 * Setting processor type for PowerPC and RS/6000
5330 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5331 you can use the `set processor' command to specify what variant of the
5332 PowerPC family you are debugging. The command
5336 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5337 following PowerPC and RS6000 variants:
5339 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5340 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5342 403GC IBM PowerPC 403GC
5343 505 Motorola PowerPC 505
5344 860 Motorola PowerPC 860 or 850
5345 601 Motorola PowerPC 601
5346 602 Motorola PowerPC 602
5347 603 Motorola/IBM PowerPC 603 or 603e
5348 604 Motorola PowerPC 604 or 604e
5349 750 Motorola/IBM PowerPC 750 or 750
5351 At the moment, this command just tells GDB what to name the
5352 special-purpose processor registers. Since almost all the affected
5353 registers are inaccessible to user-level programs, this command is
5354 only useful for remote debugging in its present form.
5358 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5359 more extensive support for HP-UX. Added features include shared
5360 library support, kernel threads and hardware watchpoints for 11.00,
5361 support for HP's ANSI C and C++ compilers, and a compatibility mode
5362 for xdb and dbx commands.
5366 HP's donation includes the new concept of catchpoints, which is a
5367 generalization of the old catch command. On HP-UX, it is now possible
5368 to catch exec, fork, and vfork, as well as library loading.
5370 This means that the existing catch command has changed; its first
5371 argument now specifies the type of catch to be set up. See the
5372 output of "help catch" for a list of catchpoint types.
5374 * Debugging across forks
5376 On HP-UX, you can choose which process to debug when a fork() happens
5381 HP has donated a curses-based terminal user interface (TUI). To get
5382 it, build with --enable-tui. Although this can be enabled for any
5383 configuration, at present it only works for native HP debugging.
5385 * GDB remote protocol additions
5387 A new protocol packet 'X' that writes binary data is now available.
5388 Default behavior is to try 'X', then drop back to 'M' if the stub
5389 fails to respond. The settable variable `remotebinarydownload'
5390 allows explicit control over the use of 'X'.
5392 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5393 full 64-bit address. The command
5395 set remoteaddresssize 32
5397 can be used to revert to the old behaviour. For existing remote stubs
5398 the change should not be noticed, as the additional address information
5401 In order to assist in debugging stubs, you may use the maintenance
5402 command `packet' to send any text string to the stub. For instance,
5404 maint packet heythere
5406 sends the packet "$heythere#<checksum>". Note that it is very easy to
5407 disrupt a debugging session by sending the wrong packet at the wrong
5410 The compare-sections command allows you to compare section data on the
5411 target to what is in the executable file without uploading or
5412 downloading, by comparing CRC checksums.
5414 * Tracing can collect general expressions
5416 You may now collect general expressions at tracepoints. This requires
5417 further additions to the target-side stub; see tracepoint.c and
5418 doc/agentexpr.texi for further details.
5420 * mask-address variable for Mips
5422 For Mips targets, you may control the zeroing of the upper 32 bits of
5423 a 64-bit address by entering `set mask-address on'. This is mainly
5424 of interest to users of embedded R4xxx and R5xxx processors.
5426 * Higher serial baud rates
5428 GDB's serial code now allows you to specify baud rates 57600, 115200,
5429 230400, and 460800 baud. (Note that your host system may not be able
5430 to achieve all of these rates.)
5434 The i960 configuration now includes an initial implementation of a
5435 builtin simulator, contributed by Jim Wilson.
5438 *** Changes in GDB-4.17:
5440 * New native configurations
5442 Alpha GNU/Linux alpha*-*-linux*
5443 Unixware 2.x i[3456]86-unixware2*
5444 Irix 6.x mips*-sgi-irix6*
5445 PowerPC GNU/Linux powerpc-*-linux*
5446 PowerPC Solaris powerpcle-*-solaris*
5447 Sparc GNU/Linux sparc-*-linux*
5448 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5452 Argonaut Risc Chip (ARC) arc-*-*
5453 Hitachi H8/300S h8300*-*-*
5454 Matsushita MN10200 w/simulator mn10200-*-*
5455 Matsushita MN10300 w/simulator mn10300-*-*
5456 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5457 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5458 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5459 Mitsubishi D10V w/simulator d10v-*-*
5460 Mitsubishi M32R/D w/simulator m32r-*-elf*
5461 Tsqware Sparclet sparclet-*-*
5462 NEC V850 w/simulator v850-*-*
5464 * New debugging protocols
5466 ARM with RDI protocol arm*-*-*
5467 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5468 DDB and LSI variants of PMON protocol mips*-*-*
5469 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5470 PowerPC with SDS protocol powerpc{,le}-*-eabi
5471 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5475 All configurations can now understand and use the DWARF 2 debugging
5476 format. The choice is automatic, if the symbol file contains DWARF 2
5481 GDB now includes basic Java language support. This support is
5482 only useful with Java compilers that produce native machine code.
5484 * solib-absolute-prefix and solib-search-path
5486 For SunOS and SVR4 shared libraries, you may now set the prefix for
5487 loading absolute shared library symbol files, and the search path for
5488 locating non-absolute shared library symbol files.
5490 * Live range splitting
5492 GDB can now effectively debug code for which GCC has performed live
5493 range splitting as part of its optimization. See gdb/doc/LRS for
5494 more details on the expected format of the stabs information.
5498 GDB's support for the GNU Hurd, including thread debugging, has been
5499 updated to work with current versions of the Hurd.
5503 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5504 instruction set. ARM GDB automatically detects when Thumb
5505 instructions are in use, and adjusts disassembly and backtracing
5510 GDB's MIPS target configurations now handle the MIP16 16-bit
5515 GDB now includes support for overlays; if an executable has been
5516 linked such that multiple sections are based at the same address, GDB
5517 will decide which section to use for symbolic info. You can choose to
5518 control the decision manually, using overlay commands, or implement
5519 additional target-side support and use "overlay load-target" to bring
5520 in the overlay mapping. Do "help overlay" for more detail.
5524 The command "info symbol <address>" displays information about
5525 the symbol at the specified address.
5529 The standard remote protocol now includes an extension that allows
5530 asynchronous collection and display of trace data. This requires
5531 extensive support in the target-side debugging stub. Tracing mode
5532 includes a new interaction mode in GDB and new commands: see the
5533 file tracepoint.c for more details.
5537 Configurations for embedded MIPS now include a simulator contributed
5538 by Cygnus Solutions. The simulator supports the instruction sets
5539 of most MIPS variants.
5543 Sparc configurations may now include the ERC32 simulator contributed
5544 by the European Space Agency. The simulator is not built into
5545 Sparc targets by default; configure with --enable-sim to include it.
5549 For target configurations that may include multiple variants of a
5550 basic architecture (such as MIPS and SH), you may now set the
5551 architecture explicitly. "set arch" sets, "info arch" lists
5552 the possible architectures.
5554 *** Changes in GDB-4.16:
5556 * New native configurations
5558 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5559 M68K NetBSD m68k-*-netbsd*
5560 PowerPC AIX 4.x powerpc-*-aix*
5561 PowerPC MacOS powerpc-*-macos*
5562 PowerPC Windows NT powerpcle-*-cygwin32
5563 RS/6000 AIX 4.x rs6000-*-aix4*
5567 ARM with RDP protocol arm-*-*
5568 I960 with MON960 i960-*-coff
5569 MIPS VxWorks mips*-*-vxworks*
5570 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5571 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5573 Matra Sparclet sparclet-*-*
5577 The powerpc-eabi configuration now includes the PSIM simulator,
5578 contributed by Andrew Cagney, with assistance from Mike Meissner.
5579 PSIM is a very elaborate model of the PowerPC, including not only
5580 basic instruction set execution, but also details of execution unit
5581 performance and I/O hardware. See sim/ppc/README for more details.
5585 GDB now works with Solaris 2.5.
5587 * Windows 95/NT native
5589 GDB will now work as a native debugger on Windows 95 and Windows NT.
5590 To build it from source, you must use the "gnu-win32" environment,
5591 which uses a DLL to emulate enough of Unix to run the GNU tools.
5592 Further information, binaries, and sources are available at
5593 ftp.cygnus.com, under pub/gnu-win32.
5595 * dont-repeat command
5597 If a user-defined command includes the command `dont-repeat', then the
5598 command will not be repeated if the user just types return. This is
5599 useful if the command is time-consuming to run, so that accidental
5600 extra keystrokes don't run the same command many times.
5602 * Send break instead of ^C
5604 The standard remote protocol now includes an option to send a break
5605 rather than a ^C to the target in order to interrupt it. By default,
5606 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5608 * Remote protocol timeout
5610 The standard remote protocol includes a new variable `remotetimeout'
5611 that allows you to set the number of seconds before GDB gives up trying
5612 to read from the target. The default value is 2.
5614 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5616 By default GDB will automatically keep track of objects as they are
5617 loaded and unloaded by the dynamic linker. By using the command `set
5618 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5619 when shared library events occur, thus allowing you to set breakpoints
5620 in shared libraries which are explicitly loaded by the inferior.
5622 Note this feature does not work on hpux8. On hpux9 you must link
5623 /usr/lib/end.o into your program. This feature should work
5624 automatically on hpux10.
5626 * Irix 5.x hardware watchpoint support
5628 Irix 5 configurations now support the use of hardware watchpoints.
5630 * Mips protocol "SYN garbage limit"
5632 When debugging a Mips target using the `target mips' protocol, you
5633 may set the number of characters that GDB will ignore by setting
5634 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5635 every character. The default value is 1050.
5637 * Recording and replaying remote debug sessions
5639 If you set `remotelogfile' to the name of a file, gdb will write to it
5640 a recording of a remote debug session. This recording may then be
5641 replayed back to gdb using "gdbreplay". See gdbserver/README for
5642 details. This is useful when you have a problem with GDB while doing
5643 remote debugging; you can make a recording of the session and send it
5644 to someone else, who can then recreate the problem.
5646 * Speedups for remote debugging
5648 GDB includes speedups for downloading and stepping MIPS systems using
5649 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5650 and more efficient S-record downloading.
5652 * Memory use reductions and statistics collection
5654 GDB now uses less memory and reports statistics about memory usage.
5655 Try the `maint print statistics' command, for example.
5657 *** Changes in GDB-4.15:
5659 * Psymtabs for XCOFF
5661 The symbol reader for AIX GDB now uses partial symbol tables. This
5662 can greatly improve startup time, especially for large executables.
5664 * Remote targets use caching
5666 Remote targets now use a data cache to speed up communication with the
5667 remote side. The data cache could lead to incorrect results because
5668 it doesn't know about volatile variables, thus making it impossible to
5669 debug targets which use memory mapped I/O devices. `set remotecache
5670 off' turns the the data cache off.
5672 * Remote targets may have threads
5674 The standard remote protocol now includes support for multiple threads
5675 in the target system, using new protocol commands 'H' and 'T'. See
5676 gdb/remote.c for details.
5680 If GDB is configured with `--enable-netrom', then it will include
5681 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5682 acts as though it is a bank of ROM on the target board, but you can
5683 write into it over the network. GDB's support consists only of
5684 support for fast loading into the emulated ROM; to debug, you must use
5685 another protocol, such as standard remote protocol. The usual
5686 sequence is something like
5688 target nrom <netrom-hostname>
5690 target remote <netrom-hostname>:1235
5694 GDB now includes support for the Apple Macintosh, as a host only. It
5695 may be run as either an MPW tool or as a standalone application, and
5696 it can debug through the serial port. All the usual GDB commands are
5697 available, but to the target command, you must supply "serial" as the
5698 device type instead of "/dev/ttyXX". See mpw-README in the main
5699 directory for more information on how to build. The MPW configuration
5700 scripts */mpw-config.in support only a few targets, and only the
5701 mips-idt-ecoff target has been tested.
5705 GDB configuration now uses autoconf. This is not user-visible,
5706 but does simplify configuration and building.
5710 GDB now supports hpux10.
5712 *** Changes in GDB-4.14:
5714 * New native configurations
5716 x86 FreeBSD i[345]86-*-freebsd
5717 x86 NetBSD i[345]86-*-netbsd
5718 NS32k NetBSD ns32k-*-netbsd
5719 Sparc NetBSD sparc-*-netbsd
5723 A29K VxWorks a29k-*-vxworks
5724 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5725 CPU32 EST-300 emulator m68*-*-est*
5726 PowerPC ELF powerpc-*-elf
5729 * Alpha OSF/1 support for procfs
5731 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5732 possible to attach to running processes. As the mounting of the /proc
5733 filesystem is optional on the Alpha, GDB automatically determines
5734 the availability of /proc during startup. This can lead to problems
5735 if /proc is unmounted after GDB has been started.
5737 * Arguments to user-defined commands
5739 User commands may accept up to 10 arguments separated by whitespace.
5740 Arguments are accessed within the user command via $arg0..$arg9. A
5743 print $arg0 + $arg1 + $arg2
5745 To execute the command use:
5748 Defines the command "adder" which prints the sum of its three arguments.
5749 Note the arguments are text substitutions, so they may reference variables,
5750 use complex expressions, or even perform inferior function calls.
5752 * New `if' and `while' commands
5754 This makes it possible to write more sophisticated user-defined
5755 commands. Both commands take a single argument, which is the
5756 expression to evaluate, and must be followed by the commands to
5757 execute, one per line, if the expression is nonzero, the list being
5758 terminated by the word `end'. The `if' command list may include an
5759 `else' word, which causes the following commands to be executed only
5760 if the expression is zero.
5762 * Fortran source language mode
5764 GDB now includes partial support for Fortran 77. It will recognize
5765 Fortran programs and can evaluate a subset of Fortran expressions, but
5766 variables and functions may not be handled correctly. GDB will work
5767 with G77, but does not yet know much about symbols emitted by other
5770 * Better HPUX support
5772 Most debugging facilities now work on dynamic executables for HPPAs
5773 running hpux9 or later. You can attach to running dynamically linked
5774 processes, but by default the dynamic libraries will be read-only, so
5775 for instance you won't be able to put breakpoints in them. To change
5776 that behavior do the following before running the program:
5782 This will cause the libraries to be mapped private and read-write.
5783 To revert to the normal behavior, do this:
5789 You cannot set breakpoints or examine data in the library until after
5790 the library is loaded if the function/data symbols do not have
5793 GDB can now also read debug symbols produced by the HP C compiler on
5794 HPPAs (sorry, no C++, Fortran or 68k support).
5796 * Target byte order now dynamically selectable
5798 You can choose which byte order to use with a target system, via the
5799 commands "set endian big" and "set endian little", and you can see the
5800 current setting by using "show endian". You can also give the command
5801 "set endian auto", in which case GDB will use the byte order
5802 associated with the executable. Currently, only embedded MIPS
5803 configurations support dynamic selection of target byte order.
5805 * New DOS host serial code
5807 This version uses DPMI interrupts to handle buffered I/O, so you
5808 no longer need to run asynctsr when debugging boards connected to
5811 *** Changes in GDB-4.13:
5813 * New "complete" command
5815 This lists all the possible completions for the rest of the line, if it
5816 were to be given as a command itself. This is intended for use by emacs.
5818 * Trailing space optional in prompt
5820 "set prompt" no longer adds a space for you after the prompt you set. This
5821 allows you to set a prompt which ends in a space or one that does not.
5823 * Breakpoint hit counts
5825 "info break" now displays a count of the number of times the breakpoint
5826 has been hit. This is especially useful in conjunction with "ignore"; you
5827 can ignore a large number of breakpoint hits, look at the breakpoint info
5828 to see how many times the breakpoint was hit, then run again, ignoring one
5829 less than that number, and this will get you quickly to the last hit of
5832 * Ability to stop printing at NULL character
5834 "set print null-stop" will cause GDB to stop printing the characters of
5835 an array when the first NULL is encountered. This is useful when large
5836 arrays actually contain only short strings.
5838 * Shared library breakpoints
5840 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5841 breakpoints in shared libraries before the executable is run.
5843 * Hardware watchpoints
5845 There is a new hardware breakpoint for the watch command for sparclite
5846 targets. See gdb/sparclite/hw_breakpoint.note.
5848 Hardware watchpoints are also now supported under GNU/Linux.
5852 Annotations have been added. These are for use with graphical interfaces,
5853 and are still experimental. Currently only gdba.el uses these.
5855 * Improved Irix 5 support
5857 GDB now works properly with Irix 5.2.
5859 * Improved HPPA support
5861 GDB now works properly with the latest GCC and GAS.
5863 * New native configurations
5865 Sequent PTX4 i[34]86-sequent-ptx4
5866 HPPA running OSF/1 hppa*-*-osf*
5867 Atari TT running SVR4 m68*-*-sysv4*
5868 RS/6000 LynxOS rs6000-*-lynxos*
5872 OS/9000 i[34]86-*-os9k
5873 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5876 * Hitachi SH7000 and E7000-PC ICE support
5878 There is now support for communicating with the Hitachi E7000-PC ICE.
5879 This is available automatically when GDB is configured for the SH.
5883 As usual, a variety of small fixes and improvements, both generic
5884 and configuration-specific. See the ChangeLog for more detail.
5886 *** Changes in GDB-4.12:
5888 * Irix 5 is now supported
5892 GDB-4.12 on the HPPA has a number of changes which make it unable
5893 to debug the output from the currently released versions of GCC and
5894 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5895 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5896 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5899 *** Changes in GDB-4.11:
5901 * User visible changes:
5905 The "set remotedebug" option is now consistent between the mips remote
5906 target, remote targets using the gdb-specific protocol, UDI (AMD's
5907 debug protocol for the 29k) and the 88k bug monitor. It is now an
5908 integer specifying a debug level (normally 0 or 1, but 2 means more
5909 debugging info for the mips target).
5911 * DEC Alpha native support
5913 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5914 debug info, but GDB works fairly well with the DEC compiler and should
5915 work with a future GCC release. See the README file for a few
5916 Alpha-specific notes.
5918 * Preliminary thread implementation
5920 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5922 * LynxOS native and target support for 386
5924 This release has been hosted on LynxOS 2.2, and also can be configured
5925 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5928 * Improvements in C++ mangling/demangling.
5930 This release has much better g++ debugging, specifically in name
5931 mangling/demangling, virtual function calls, print virtual table,
5932 call methods, ...etc.
5934 *** Changes in GDB-4.10:
5936 * User visible changes:
5938 Remote debugging using the GDB-specific (`target remote') protocol now
5939 supports the `load' command. This is only useful if you have some
5940 other way of getting the stub to the target system, and you can put it
5941 somewhere in memory where it won't get clobbered by the download.
5943 Filename completion now works.
5945 When run under emacs mode, the "info line" command now causes the
5946 arrow to point to the line specified. Also, "info line" prints
5947 addresses in symbolic form (as well as hex).
5949 All vxworks based targets now support a user settable option, called
5950 vxworks-timeout. This option represents the number of seconds gdb
5951 should wait for responses to rpc's. You might want to use this if
5952 your vxworks target is, perhaps, a slow software simulator or happens
5953 to be on the far side of a thin network line.
5957 This release contains support for using a DEC alpha as a GDB host for
5958 cross debugging. Native alpha debugging is not supported yet.
5961 *** Changes in GDB-4.9:
5965 This is the first GDB release which is accompanied by a matching testsuite.
5966 The testsuite requires installation of dejagnu, which should be available
5967 via ftp from most sites that carry GNU software.
5971 'Cfront' style demangling has had its name changed to 'ARM' style, to
5972 emphasize that it was written from the specifications in the C++ Annotated
5973 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5974 disclaimers, it still generated too much confusion with users attempting to
5975 use gdb with AT&T cfront.
5979 GDB now uses a standard remote interface to a simulator library.
5980 So far, the library contains simulators for the Zilog Z8001/2, the
5981 Hitachi H8/300, H8/500 and Super-H.
5983 * New targets supported
5985 H8/300 simulator h8300-hitachi-hms or h8300hms
5986 H8/500 simulator h8500-hitachi-hms or h8500hms
5987 SH simulator sh-hitachi-hms or sh
5988 Z8000 simulator z8k-zilog-none or z8ksim
5989 IDT MIPS board over serial line mips-idt-ecoff
5991 Cross-debugging to GO32 targets is supported. It requires a custom
5992 version of the i386-stub.c module which is integrated with the
5993 GO32 memory extender.
5995 * New remote protocols
5997 MIPS remote debugging protocol.
5999 * New source languages supported
6001 This version includes preliminary support for Chill, a Pascal like language
6002 used by telecommunications companies. Chill support is also being integrated
6003 into the GNU compiler, but we don't know when it will be publically available.
6006 *** Changes in GDB-4.8:
6008 * HP Precision Architecture supported
6010 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6011 version of this support was available as a set of patches from the
6012 University of Utah. GDB does not support debugging of programs
6013 compiled with the HP compiler, because HP will not document their file
6014 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6015 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6017 Many problems in the preliminary version have been fixed.
6019 * Faster and better demangling
6021 We have improved template demangling and fixed numerous bugs in the GNU style
6022 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6023 character types (wchar_t) are now supported. Demangling of each symbol is now
6024 only done once, and is cached when the symbol table for a file is read in.
6025 This results in a small increase in memory usage for C programs, a moderate
6026 increase in memory usage for C++ programs, and a fantastic speedup in
6029 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6030 from the specifications in the Annotated Reference Manual, which AT&T's
6031 compiler does not actually implement.
6033 * G++ multiple inheritance compiler problem
6035 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6036 inheritance lattices was reworked to properly discover ambiguities. We
6037 recently found an example which causes this new algorithm to fail in a
6038 very subtle way, producing bad debug information for those classes.
6039 The file 'gcc.patch' (in this directory) can be applied to gcc to
6040 circumvent the problem. A future GCC release will contain a complete
6043 The previous G++ debug info problem (mentioned below for the gdb-4.7
6044 release) is fixed in gcc version 2.3.2.
6046 * Improved configure script
6048 The `configure' script will now attempt to guess your system type if
6049 you don't supply a host system type. The old scheme of supplying a
6050 host system triplet is preferable over using this. All the magic is
6051 done in the new `config.guess' script. Examine it for details.
6053 We have also brought our configure script much more in line with the FSF's
6054 version. It now supports the --with-xxx options. In particular,
6055 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6056 The resulting GDB will not be able to read arbitrary object file formats --
6057 only the format ``expected'' to be used on the configured target system.
6058 We hope to make this the default in a future release.
6060 * Documentation improvements
6062 There's new internal documentation on how to modify GDB, and how to
6063 produce clean changes to the code. We implore people to read it
6064 before submitting changes.
6066 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6067 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6068 `info' files are also provided. To build `info' files from scratch,
6069 you will need the latest `makeinfo' release, which will be available in
6070 a future texinfo-X.Y release.
6072 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6073 We're not sure exactly which versions have this problem, but it has
6074 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6075 or better. If that isn't possible, there is a patch in
6076 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6077 around this problem.
6081 GDB now supports array constants that can be used in expressions typed in by
6082 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6083 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6086 The new directory `gdb/sparclite' contains a program that demonstrates
6087 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6089 * New native hosts supported
6091 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6092 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6094 * New targets supported
6096 AMD 29k family via UDI a29k-amd-udi or udi29k
6098 * New file formats supported
6100 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6101 HPUX core files, and SCO 3.2v2 core files.
6105 Attaching to processes now works again; thanks for the many bug reports.
6107 We have also stomped on a bunch of core dumps caused by
6108 printf_filtered("%s") problems.
6110 We eliminated a copyright problem on the rpc and ptrace header files
6111 for VxWorks, which was discovered at the last minute during the 4.7
6112 release. You should now be able to build a VxWorks GDB.
6114 You can now interrupt gdb while an attached process is running. This
6115 will cause the attached process to stop, and give control back to GDB.
6117 We fixed problems caused by using too many file descriptors
6118 for reading symbols from object files and libraries. This was
6119 especially a problem for programs that used many (~100) shared
6122 The `step' command now only enters a subroutine if there is line number
6123 information for the subroutine. Otherwise it acts like the `next'
6124 command. Previously, `step' would enter subroutines if there was
6125 any debugging information about the routine. This avoids problems
6126 when using `cc -g1' on MIPS machines.
6128 * Internal improvements
6130 GDB's internal interfaces have been improved to make it easier to support
6131 debugging of multiple languages in the future.
6133 GDB now uses a common structure for symbol information internally.
6134 Minimal symbols (derived from linkage symbols in object files), partial
6135 symbols (from a quick scan of debug information), and full symbols
6136 contain a common subset of information, making it easier to write
6137 shared code that handles any of them.
6139 * New command line options
6141 We now accept --silent as an alias for --quiet.
6145 The memory-mapped-malloc library is now licensed under the GNU Library
6146 General Public License.
6148 *** Changes in GDB-4.7:
6150 * Host/native/target split
6152 GDB has had some major internal surgery to untangle the support for
6153 hosts and remote targets. Now, when you configure GDB for a remote
6154 target, it will no longer load in all of the support for debugging
6155 local programs on the host. When fully completed and tested, this will
6156 ensure that arbitrary host/target combinations are possible.
6158 The primary conceptual shift is to separate the non-portable code in
6159 GDB into three categories. Host specific code is required any time GDB
6160 is compiled on that host, regardless of the target. Target specific
6161 code relates to the peculiarities of the target, but can be compiled on
6162 any host. Native specific code is everything else: it can only be
6163 built when the host and target are the same system. Child process
6164 handling and core file support are two common `native' examples.
6166 GDB's use of /proc for controlling Unix child processes is now cleaner.
6167 It has been split out into a single module under the `target_ops' vector,
6168 plus two native-dependent functions for each system that uses /proc.
6170 * New hosts supported
6172 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6173 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6174 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6176 * New targets supported
6178 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6179 68030 and CPU32 m68030-*-*, m68332-*-*
6181 * New native hosts supported
6183 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6184 (386bsd is not well tested yet)
6185 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6187 * New file formats supported
6189 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6190 supports reading of `a.out.adobe' object files, which are an a.out
6191 format extended with minimal information about multiple sections.
6195 `show copying' is the same as the old `info copying'.
6196 `show warranty' is the same as `info warrantee'.
6197 These were renamed for consistency. The old commands continue to work.
6199 `info handle' is a new alias for `info signals'.
6201 You can now define pre-command hooks, which attach arbitrary command
6202 scripts to any command. The commands in the hook will be executed
6203 prior to the user's command. You can also create a hook which will be
6204 executed whenever the program stops. See gdb.texinfo.
6208 We now deal with Cfront style name mangling, and can even extract type
6209 info from mangled symbols. GDB can automatically figure out which
6210 symbol mangling style your C++ compiler uses.
6212 Calling of methods and virtual functions has been improved as well.
6216 The crash that occured when debugging Sun Ansi-C compiled binaries is
6217 fixed. This was due to mishandling of the extra N_SO stabs output
6220 We also finally got Ultrix 4.2 running in house, and fixed core file
6221 support, with help from a dozen people on the net.
6223 John M. Farrell discovered that the reason that single-stepping was so
6224 slow on all of the Mips based platforms (primarily SGI and DEC) was
6225 that we were trying to demangle and lookup a symbol used for internal
6226 purposes on every instruction that was being stepped through. Changing
6227 the name of that symbol so that it couldn't be mistaken for a C++
6228 mangled symbol sped things up a great deal.
6230 Rich Pixley sped up symbol lookups in general by getting much smarter
6231 about when C++ symbol mangling is necessary. This should make symbol
6232 completion (TAB on the command line) much faster. It's not as fast as
6233 we'd like, but it's significantly faster than gdb-4.6.
6237 A new user controllable variable 'call_scratch_address' can
6238 specify the location of a scratch area to be used when GDB
6239 calls a function in the target. This is necessary because the
6240 usual method of putting the scratch area on the stack does not work
6241 in systems that have separate instruction and data spaces.
6243 We integrated changes to support the 29k UDI (Universal Debugger
6244 Interface), but discovered at the last minute that we didn't have all
6245 of the appropriate copyright paperwork. We are working with AMD to
6246 resolve this, and hope to have it available soon.
6250 We have sped up the remote serial line protocol, especially for targets
6251 with lots of registers. It now supports a new `expedited status' ('T')
6252 message which can be used in place of the existing 'S' status message.
6253 This allows the remote stub to send only the registers that GDB
6254 needs to make a quick decision about single-stepping or conditional
6255 breakpoints, eliminating the need to fetch the entire register set for
6256 each instruction being stepped through.
6258 The GDB remote serial protocol now implements a write-through cache for
6259 registers, only re-reading the registers if the target has run.
6261 There is also a new remote serial stub for SPARC processors. You can
6262 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6263 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6264 processor with a serial port.
6268 Configure.in files have become much easier to read and modify. A new
6269 `table driven' format makes it more obvious what configurations are
6270 supported, and what files each one uses.
6274 There is a new opcodes library which will eventually contain all of the
6275 disassembly routines and opcode tables. At present, it only contains
6276 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6277 disassembler (binutils/objdump) to share these routines.
6279 The libiberty library is now copylefted under the GNU Library General
6280 Public License. This allows more liberal use, and was done so libg++
6281 can use it. This makes no difference to GDB, since the Library License
6282 grants all the rights from the General Public License.
6286 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6287 reference to the stabs symbol info used by the debugger. It is (as far
6288 as we know) the only published document on this fascinating topic. We
6289 encourage you to read it, compare it to the stabs information on your
6290 system, and send improvements on the document in general (to
6291 bug-gdb@prep.ai.mit.edu).
6293 And, of course, many bugs have been fixed.
6296 *** Changes in GDB-4.6:
6298 * Better support for C++ function names
6300 GDB now accepts as input the "demangled form" of C++ overloaded function
6301 names and member function names, and can do command completion on such names
6302 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6303 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6304 Make use of command completion, it is your friend.
6306 GDB also now accepts a variety of C++ mangled symbol formats. They are
6307 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6308 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6309 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6310 for the list of formats.
6312 * G++ symbol mangling problem
6314 Recent versions of gcc have a bug in how they emit debugging information for
6315 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6316 directory) can be applied to gcc to fix the problem. Alternatively, if you
6317 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6318 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6319 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6322 * New 'maintenance' command
6324 All of the commands related to hacking GDB internals have been moved out of
6325 the main command set, and now live behind the 'maintenance' command. This
6326 can also be abbreviated as 'mt'. The following changes were made:
6328 dump-me -> maintenance dump-me
6329 info all-breakpoints -> maintenance info breakpoints
6330 printmsyms -> maintenance print msyms
6331 printobjfiles -> maintenance print objfiles
6332 printpsyms -> maintenance print psymbols
6333 printsyms -> maintenance print symbols
6335 The following commands are new:
6337 maintenance demangle Call internal GDB demangler routine to
6338 demangle a C++ link name and prints the result.
6339 maintenance print type Print a type chain for a given symbol
6341 * Change to .gdbinit file processing
6343 We now read the $HOME/.gdbinit file before processing the argv arguments
6344 (e.g. reading symbol files or core files). This allows global parameters to
6345 be set, which will apply during the symbol reading. The ./.gdbinit is still
6346 read after argv processing.
6348 * New hosts supported
6350 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6352 GNU/Linux support i386-unknown-linux or linux
6354 We are also including code to support the HP/PA running BSD and HPUX. This
6355 is almost guaranteed not to work, as we didn't have time to test or build it
6356 for this release. We are including it so that the more adventurous (or
6357 masochistic) of you can play with it. We also had major problems with the
6358 fact that the compiler that we got from HP doesn't support the -g option.
6361 * New targets supported
6363 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6365 * More smarts about finding #include files
6367 GDB now remembers the compilation directory for all include files, and for
6368 all files from which C is generated (like yacc and lex sources). This
6369 greatly improves GDB's ability to find yacc/lex sources, and include files,
6370 especially if you are debugging your program from a directory different from
6371 the one that contains your sources.
6373 We also fixed a bug which caused difficulty with listing and setting
6374 breakpoints in include files which contain C code. (In the past, you had to
6375 try twice in order to list an include file that you hadn't looked at before.)
6377 * Interesting infernals change
6379 GDB now deals with arbitrary numbers of sections, where the symbols for each
6380 section must be relocated relative to that section's landing place in the
6381 target's address space. This work was needed to support ELF with embedded
6382 stabs used by Solaris-2.0.
6384 * Bug fixes (of course!)
6386 There have been loads of fixes for the following things:
6387 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6388 i960, stabs, DOS(GO32), procfs, etc...
6390 See the ChangeLog for details.
6392 *** Changes in GDB-4.5:
6394 * New machines supported (host and target)
6396 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6398 SGI Irix-4.x mips-sgi-irix4 or iris4
6400 * New malloc package
6402 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6403 Mmalloc is capable of handling mutiple heaps of memory. It is also
6404 capable of saving a heap to a file, and then mapping it back in later.
6405 This can be used to greatly speedup the startup of GDB by using a
6406 pre-parsed symbol table which lives in a mmalloc managed heap. For
6407 more details, please read mmalloc/mmalloc.texi.
6411 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6412 'help info proc' for details.
6414 * MIPS ecoff symbol table format
6416 The code that reads MIPS symbol table format is now supported on all hosts.
6417 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6420 * File name changes for MS-DOS
6422 Many files in the config directories have been renamed to make it easier to
6423 support GDB on MS-DOSe systems (which have very restrictive file name
6424 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6425 environment) is close to working but has some remaining problems. Note
6426 that debugging of DOS programs is not supported, due to limitations
6427 in the ``operating system'', but it can be used to host cross-debugging.
6429 * Cross byte order fixes
6431 Many fixes have been made to support cross debugging of Sparc and MIPS
6432 targets from hosts whose byte order differs.
6434 * New -mapped and -readnow options
6436 If memory-mapped files are available on your system through the 'mmap'
6437 system call, you can use the -mapped option on the `file' or
6438 `symbol-file' commands to cause GDB to write the symbols from your
6439 program into a reusable file. If the program you are debugging is
6440 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6441 Future GDB debugging sessions will notice the presence of this file,
6442 and will quickly map in symbol information from it, rather than reading
6443 the symbol table from the executable program. Using the '-mapped'
6444 option in a GDB `file' or `symbol-file' command has the same effect as
6445 starting GDB with the '-mapped' command-line option.
6447 You can cause GDB to read the entire symbol table immediately by using
6448 the '-readnow' option with any of the commands that load symbol table
6449 information (or on the GDB command line). This makes the command
6450 slower, but makes future operations faster.
6452 The -mapped and -readnow options are typically combined in order to
6453 build a `fred.syms' file that contains complete symbol information.
6454 A simple GDB invocation to do nothing but build a `.syms' file for future
6457 gdb -batch -nx -mapped -readnow programname
6459 The `.syms' file is specific to the host machine on which GDB is run.
6460 It holds an exact image of GDB's internal symbol table. It cannot be
6461 shared across multiple host platforms.
6463 * longjmp() handling
6465 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6466 siglongjmp() without losing control. This feature has not yet been ported to
6467 all systems. It currently works on many 386 platforms, all MIPS-based
6468 platforms (SGI, DECstation, etc), and Sun3/4.
6472 Preliminary work has been put in to support the new Solaris OS from Sun. At
6473 this time, it can control and debug processes, but it is not capable of
6478 As always, many many bug fixes. The major areas were with g++, and mipsread.
6479 People using the MIPS-based platforms should experience fewer mysterious
6480 crashes and trashed symbol tables.
6482 *** Changes in GDB-4.4:
6484 * New machines supported (host and target)
6486 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6488 BSD Reno on Vax vax-dec-bsd
6489 Ultrix on Vax vax-dec-ultrix
6491 * New machines supported (target)
6493 AMD 29000 embedded, using EBMON a29k-none-none
6497 GDB continues to improve its handling of C++. `References' work better.
6498 The demangler has also been improved, and now deals with symbols mangled as
6499 per the Annotated C++ Reference Guide.
6501 GDB also now handles `stabs' symbol information embedded in MIPS
6502 `ecoff' symbol tables. Since the ecoff format was not easily
6503 extensible to handle new languages such as C++, this appeared to be a
6504 good way to put C++ debugging info into MIPS binaries. This option
6505 will be supported in the GNU C compiler, version 2, when it is
6508 * New features for SVR4
6510 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6511 shared libraries. Debugging dynamically linked programs should present
6512 only minor differences from debugging statically linked programs.
6514 The `info proc' command will print out information about any process
6515 on an SVR4 system (including the one you are debugging). At the moment,
6516 it prints the address mappings of the process.
6518 If you bring up GDB on another SVR4 system, please send mail to
6519 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6521 * Better dynamic linking support in SunOS
6523 Reading symbols from shared libraries which contain debugging symbols
6524 now works properly. However, there remain issues such as automatic
6525 skipping of `transfer vector' code during function calls, which
6526 make it harder to debug code in a shared library, than to debug the
6527 same code linked statically.
6531 GDB is now using the latest `getopt' routines from the FSF. This
6532 version accepts the -- prefix for options with long names. GDB will
6533 continue to accept the old forms (-option and +option) as well.
6534 Various single letter abbreviations for options have been explicity
6535 added to the option table so that they won't get overshadowed in the
6536 future by other options that begin with the same letter.
6540 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6541 Many assorted bugs have been handled. Many more remain to be handled.
6542 See the various ChangeLog files (primarily in gdb and bfd) for details.
6545 *** Changes in GDB-4.3:
6547 * New machines supported (host and target)
6549 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6550 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6551 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6553 * Almost SCO Unix support
6555 We had hoped to support:
6556 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6557 (except for core file support), but we discovered very late in the release
6558 that it has problems with process groups that render gdb unusable. Sorry
6559 about that. I encourage people to fix it and post the fixes.
6561 * Preliminary ELF and DWARF support
6563 GDB can read ELF object files on System V Release 4, and can handle
6564 debugging records for C, in DWARF format, in ELF files. This support
6565 is preliminary. If you bring up GDB on another SVR4 system, please
6566 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6571 GDB now uses the latest `readline' library. One user-visible change
6572 is that two tabs will list possible command completions, which previously
6573 required typing M-? (meta-question mark, or ESC ?).
6577 The `stepi' bug that many of you noticed has been squashed.
6578 Many bugs in C++ have been handled. Many more remain to be handled.
6579 See the various ChangeLog files (primarily in gdb and bfd) for details.
6581 * State of the MIPS world (in case you wondered):
6583 GDB can understand the symbol tables emitted by the compilers
6584 supplied by most vendors of MIPS-based machines, including DEC. These
6585 symbol tables are in a format that essentially nobody else uses.
6587 Some versions of gcc come with an assembler post-processor called
6588 mips-tfile. This program is required if you want to do source-level
6589 debugging of gcc-compiled programs. I believe FSF does not ship
6590 mips-tfile with gcc version 1, but it will eventually come with gcc
6593 Debugging of g++ output remains a problem. g++ version 1.xx does not
6594 really support it at all. (If you're lucky, you should be able to get
6595 line numbers and stack traces to work, but no parameters or local
6596 variables.) With some work it should be possible to improve the
6599 When gcc version 2 is released, you will have somewhat better luck.
6600 However, even then you will get confusing results for inheritance and
6603 We will eventually provide full debugging of g++ output on
6604 DECstations. This will probably involve some kind of stabs-in-ecoff
6605 encapulation, but the details have not been worked out yet.
6608 *** Changes in GDB-4.2:
6610 * Improved configuration
6612 Only one copy of `configure' exists now, and it is not self-modifying.
6613 Porting BFD is simpler.
6617 The `step' and `next' commands now only stop at the first instruction
6618 of a source line. This prevents the multiple stops that used to occur
6619 in switch statements, for-loops, etc. `Step' continues to stop if a
6620 function that has debugging information is called within the line.
6624 Lots of small bugs fixed. More remain.
6626 * New host supported (not target)
6628 Intel 386 PC clone running Mach i386-none-mach
6631 *** Changes in GDB-4.1:
6633 * Multiple source language support
6635 GDB now has internal scaffolding to handle several source languages.
6636 It determines the type of each source file from its filename extension,
6637 and will switch expression parsing and number formatting to match the
6638 language of the function in the currently selected stack frame.
6639 You can also specifically set the language to be used, with
6640 `set language c' or `set language modula-2'.
6644 GDB now has preliminary support for the GNU Modula-2 compiler,
6645 currently under development at the State University of New York at
6646 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6647 continue through the fall of 1991 and into 1992.
6649 Other Modula-2 compilers are currently not supported, and attempting to
6650 debug programs compiled with them will likely result in an error as the
6651 symbol table is read. Feel free to work on it, though!
6653 There are hooks in GDB for strict type checking and range checking,
6654 in the `Modula-2 philosophy', but they do not currently work.
6658 GDB can now write to executable and core files (e.g. patch
6659 a variable's value). You must turn this switch on, specify
6660 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6661 by assigning a new value to a variable. Modifications take
6664 * Automatic SunOS shared library reading
6666 When you run your program, GDB automatically determines where its
6667 shared libraries (if any) have been loaded, and reads their symbols.
6668 The `share' command is no longer needed. This also works when
6669 examining core files.
6673 You can specify the number of lines that the `list' command shows.
6676 * New machines supported (host and target)
6678 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6679 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6680 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6682 * New hosts supported (not targets)
6684 IBM RT/PC: romp-ibm-aix or rtpc
6686 * New targets supported (not hosts)
6688 AMD 29000 embedded with COFF a29k-none-coff
6689 AMD 29000 embedded with a.out a29k-none-aout
6690 Ultracomputer remote kernel debug a29k-nyu-kern
6692 * New remote interfaces
6698 *** Changes in GDB-4.0:
6702 Wide output is wrapped at good places to make the output more readable.
6704 Gdb now supports cross-debugging from a host machine of one type to a
6705 target machine of another type. Communication with the target system
6706 is over serial lines. The ``target'' command handles connecting to the
6707 remote system; the ``load'' command will download a program into the
6708 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6709 also supports debugging of realtime processes running under VxWorks,
6710 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6711 stub on the target system.
6713 New CPUs supported include the AMD 29000 and Intel 960.
6715 GDB now reads object files and symbol tables via a ``binary file''
6716 library, which allows a single copy of GDB to debug programs of multiple
6717 object file types such as a.out and coff.
6719 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6720 refcard.dvi and refcard.ps are available to format it).
6723 * Control-Variable user interface simplified
6725 All variables that control the operation of the debugger can be set
6726 by the ``set'' command, and displayed by the ``show'' command.
6728 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6729 ``Show prompt'' produces the response:
6730 Gdb's prompt is new-gdb=>.
6732 What follows are the NEW set commands. The command ``help set'' will
6733 print a complete list of old and new set commands. ``help set FOO''
6734 will give a longer description of the variable FOO. ``show'' will show
6735 all of the variable descriptions and their current settings.
6737 confirm on/off: Enables warning questions for operations that are
6738 hard to recover from, e.g. rerunning the program while
6739 it is already running. Default is ON.
6741 editing on/off: Enables EMACS style command line editing
6742 of input. Previous lines can be recalled with
6743 control-P, the current line can be edited with control-B,
6744 you can search for commands with control-R, etc.
6747 history filename NAME: NAME is where the gdb command history
6748 will be stored. The default is .gdb_history,
6749 or the value of the environment variable
6752 history size N: The size, in commands, of the command history. The
6753 default is 256, or the value of the environment variable
6756 history save on/off: If this value is set to ON, the history file will
6757 be saved after exiting gdb. If set to OFF, the
6758 file will not be saved. The default is OFF.
6760 history expansion on/off: If this value is set to ON, then csh-like
6761 history expansion will be performed on
6762 command line input. The default is OFF.
6764 radix N: Sets the default radix for input and output. It can be set
6765 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6766 in the current radix, so "set radix 10" is always a no-op.
6768 height N: This integer value is the number of lines on a page. Default
6769 is 24, the current `stty rows'' setting, or the ``li#''
6770 setting from the termcap entry matching the environment
6773 width N: This integer value is the number of characters on a line.
6774 Default is 80, the current `stty cols'' setting, or the ``co#''
6775 setting from the termcap entry matching the environment
6778 Note: ``set screensize'' is obsolete. Use ``set height'' and
6779 ``set width'' instead.
6781 print address on/off: Print memory addresses in various command displays,
6782 such as stack traces and structure values. Gdb looks
6783 more ``symbolic'' if you turn this off; it looks more
6784 ``machine level'' with it on. Default is ON.
6786 print array on/off: Prettyprint arrays. New convenient format! Default
6789 print demangle on/off: Print C++ symbols in "source" form if on,
6792 print asm-demangle on/off: Same, for assembler level printouts
6795 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6798 * Support for Epoch Environment.
6800 The epoch environment is a version of Emacs v18 with windowing. One
6801 new command, ``inspect'', is identical to ``print'', except that if you
6802 are running in the epoch environment, the value is printed in its own
6806 * Support for Shared Libraries
6808 GDB can now debug programs and core files that use SunOS shared libraries.
6809 Symbols from a shared library cannot be referenced
6810 before the shared library has been linked with the program (this
6811 happens after you type ``run'' and before the function main() is entered).
6812 At any time after this linking (including when examining core files
6813 from dynamically linked programs), gdb reads the symbols from each
6814 shared library when you type the ``sharedlibrary'' command.
6815 It can be abbreviated ``share''.
6817 sharedlibrary REGEXP: Load shared object library symbols for files
6818 matching a unix regular expression. No argument
6819 indicates to load symbols for all shared libraries.
6821 info sharedlibrary: Status of loaded shared libraries.
6826 A watchpoint stops execution of a program whenever the value of an
6827 expression changes. Checking for this slows down execution
6828 tremendously whenever you are in the scope of the expression, but is
6829 quite useful for catching tough ``bit-spreader'' or pointer misuse
6830 problems. Some machines such as the 386 have hardware for doing this
6831 more quickly, and future versions of gdb will use this hardware.
6833 watch EXP: Set a watchpoint (breakpoint) for an expression.
6835 info watchpoints: Information about your watchpoints.
6837 delete N: Deletes watchpoint number N (same as breakpoints).
6838 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6839 enable N: Re-enables watchpoint number N (same as breakpoints).
6842 * C++ multiple inheritance
6844 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6847 * C++ exception handling
6849 Gdb now supports limited C++ exception handling. Besides the existing
6850 ability to breakpoint on an exception handler, gdb can breakpoint on
6851 the raising of an exception (before the stack is peeled back to the
6854 catch FOO: If there is a FOO exception handler in the dynamic scope,
6855 set a breakpoint to catch exceptions which may be raised there.
6856 Multiple exceptions (``catch foo bar baz'') may be caught.
6858 info catch: Lists all exceptions which may be caught in the
6859 current stack frame.
6862 * Minor command changes
6864 The command ``call func (arg, arg, ...)'' now acts like the print
6865 command, except it does not print or save a value if the function's result
6866 is void. This is similar to dbx usage.
6868 The ``up'' and ``down'' commands now always print the frame they end up
6869 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6870 frames without printing.
6872 * New directory command
6874 'dir' now adds directories to the FRONT of the source search path.
6875 The path starts off empty. Source files that contain debug information
6876 about the directory in which they were compiled can be found even
6877 with an empty path; Sun CC and GCC include this information. If GDB can't
6878 find your source file in the current directory, type "dir .".
6880 * Configuring GDB for compilation
6882 For normal use, type ``./configure host''. See README or gdb.texinfo
6885 GDB now handles cross debugging. If you are remotely debugging between
6886 two different machines, type ``./configure host -target=targ''.
6887 Host is the machine where GDB will run; targ is the machine
6888 where the program that you are debugging will run.