1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * GDB now supports access to the guarded-storage-control registers and the
7 software-based guarded-storage broadcast control registers on IBM z14.
9 * On Unix systems, GDB now supports transmitting environment variables
10 that are to be set or unset to GDBserver. These variables will
11 affect the environment to be passed to the remote inferior.
13 To inform GDB of environment variables that are to be transmitted to
14 GDBserver, use the "set environment" command. Only user set
15 environment variables are sent to GDBserver.
17 To inform GDB of environment variables that are to be unset before
18 the remote inferior is started by the GDBserver, use the "unset
23 ** New events gdb.new_inferior, gdb.inferior_deleted, and
24 gdb.new_thread are emitted. See the manual for further
27 * New features in the GDB remote stub, GDBserver
29 ** New "--selftest" command line option runs some GDBserver self
30 tests. These self tests are disabled in releases.
32 ** On Unix systems, GDBserver now does globbing expansion and variable
33 substitution in inferior command line arguments.
35 This is done by starting inferiors using a shell, like GDB does.
36 See "set startup-with-shell" in the user manual for how to disable
37 this from GDB when using "target extended-remote". When using
38 "target remote", you can disable the startup with shell by using the
39 new "--no-startup-with-shell" GDBserver command line option.
41 ** On Unix systems, GDBserver now supports receiving environment
42 variables that are to be set or unset from GDB. These variables
43 will affect the environment to be passed to the inferior.
47 QEnvironmentHexEncoded
48 Inform GDBserver of an environment variable that is to be passed to
49 the inferior when starting it.
52 Inform GDBserver of an environment variable that is to be unset
53 before starting the remote inferior.
56 Inform GDBserver that the environment should be reset (i.e.,
57 user-set environment variables should be unset).
60 Indicates whether the inferior must be started with a shell or not.
62 * The "maintenance print c-tdesc" command now takes an optional
63 argument which is the file name of XML target description.
65 * The "maintenance selftest" command now takes an optional argument to
66 filter the tests to be run.
71 Set and show compilation command used for compiling and injecting code
72 with the 'compile' commands.
74 set debug separate-debug-file
75 show debug separate-debug-file
76 Control the display of debug output about separate debug file search.
79 List the registered selftests.
82 Start the debugged program stopping at the first instruction.
84 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
87 * Safer/improved support for debugging with no debug info
89 GDB no longer assumes functions with no debug information return
92 This means that GDB now refuses to call such functions unless you
93 tell it the function's type, by either casting the call to the
94 declared return type, or by casting the function to a function
95 pointer of the right type, and calling that:
97 (gdb) p getenv ("PATH")
98 'getenv' has unknown return type; cast the call to its declared return type
99 (gdb) p (char *) getenv ("PATH")
100 $1 = 0x7fffffffe "/usr/local/bin:/"...
101 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
102 $2 = 0x7fffffffe "/usr/local/bin:/"...
104 Similarly, GDB no longer assumes that global variables with no debug
105 info have type 'int', and refuses to print the variable's value
106 unless you tell it the variable's type:
109 'var' has unknown type; cast it to its declared type
113 * New native configurations
115 FreeBSD/aarch64 aarch64*-*-freebsd*
119 FreeBSD/aarch64 aarch64*-*-freebsd*
121 *** Changes in GDB 8.0
123 * GDB now supports access to the PKU register on GNU/Linux. The register is
124 added by the Memory Protection Keys for Userspace feature which will be
125 available in future Intel CPUs.
127 * GDB now supports C++11 rvalue references.
131 ** New functions to start, stop and access a running btrace recording.
132 ** Rvalue references are now supported in gdb.Type.
134 * GDB now supports recording and replaying rdrand and rdseed Intel 64
137 * Building GDB and GDBserver now requires a C++11 compiler.
139 For example, GCC 4.8 or later.
141 It is no longer possible to build GDB or GDBserver with a C
142 compiler. The --disable-build-with-cxx configure option has been
145 * Building GDB and GDBserver now requires GNU make >= 3.81.
147 It is no longer supported to build GDB or GDBserver with another
148 implementation of the make program or an earlier version of GNU make.
150 * Native debugging on MS-Windows supports command-line redirection
152 Command-line arguments used for starting programs on MS-Windows can
153 now include redirection symbols supported by native Windows shells,
154 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
155 as "run", "start", and "set args", as well as the corresponding MI
158 * Support for thread names on MS-Windows.
160 GDB now catches and handles the special exception that programs
161 running on MS-Windows use to assign names to threads in the
164 * Support for Java programs compiled with gcj has been removed.
166 * User commands now accept an unlimited number of arguments.
167 Previously, only up to 10 was accepted.
169 * The "eval" command now expands user-defined command arguments.
171 This makes it easier to process a variable number of arguments:
176 eval "print $arg%d", $i
181 * Target descriptions can now describe registers for sparc32 and sparc64.
183 * GDB now supports DWARF version 5 (debug information format).
184 Its .debug_names index is not yet supported.
186 * New native configurations
188 FreeBSD/mips mips*-*-freebsd
192 Synopsys ARC arc*-*-elf32
193 FreeBSD/mips mips*-*-freebsd
195 * Removed targets and native configurations
197 Alpha running FreeBSD alpha*-*-freebsd*
198 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
203 Erases all the flash memory regions reported by the target.
205 maint print arc arc-instruction address
206 Print internal disassembler information about instruction at a given address.
210 set disassembler-options
211 show disassembler-options
212 Controls the passing of target specific information to the disassembler.
213 If it is necessary to specify more than one disassembler option then
214 multiple options can be placed together into a comma separated list.
215 The default value is the empty string. Currently, the only supported
216 targets are ARM, PowerPC and S/390.
221 Erases all the flash memory regions reported by the target. This is
222 equivalent to the CLI command flash-erase.
224 -file-list-shared-libraries
225 List the shared libraries in the program. This is
226 equivalent to the CLI command "info shared".
228 *** Changes in GDB 7.12
230 * GDB and GDBserver now build with a C++ compiler by default.
232 The --enable-build-with-cxx configure option is now enabled by
233 default. One must now explicitly configure with
234 --disable-build-with-cxx in order to build with a C compiler. This
235 option will be removed in a future release.
237 * GDBserver now supports recording btrace without maintaining an active
240 * GDB now supports a negative repeat count in the 'x' command to examine
241 memory backward from the given address. For example:
244 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
245 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
246 (gdb) x/-5i 0x0000000000400580
247 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
248 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
249 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
250 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
251 0x40057b <main(int, char**)+25>:
252 callq 0x400536 <Func1(int, char const*)>
254 * Fortran: Support structures with fields of dynamic types and
255 arrays of dynamic types.
257 * The symbol dumping maintenance commands have new syntax.
258 maint print symbols [-pc address] [--] [filename]
259 maint print symbols [-objfile objfile] [-source source] [--] [filename]
260 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
261 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
262 maint print msymbols [-objfile objfile] [--] [filename]
264 * GDB now supports multibit bitfields and enums in target register
267 * New Python-based convenience function $_as_string(val), which returns
268 the textual representation of a value. This function is especially
269 useful to obtain the text label of an enum value.
271 * Intel MPX bound violation handling.
273 Segmentation faults caused by a Intel MPX boundary violation
274 now display the kind of violation (upper or lower), the memory
275 address accessed and the memory bounds, along with the usual
276 signal received and code location.
280 Program received signal SIGSEGV, Segmentation fault
281 Upper bound violation while accessing address 0x7fffffffc3b3
282 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
283 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
285 * Rust language support.
286 GDB now supports debugging programs written in the Rust programming
287 language. See https://www.rust-lang.org/ for more information about
290 * Support for running interpreters on specified input/output devices
292 GDB now supports a new mechanism that allows frontends to provide
293 fully featured GDB console views, as a better alternative to
294 building such views on top of the "-interpreter-exec console"
295 command. See the new "new-ui" command below. With that command,
296 frontends can now start GDB in the traditional command-line mode
297 running in an embedded terminal emulator widget, and create a
298 separate MI interpreter running on a specified i/o device. In this
299 way, GDB handles line editing, history, tab completion, etc. in the
300 console all by itself, and the GUI uses the separate MI interpreter
301 for its own control and synchronization, invisible to the command
304 * The "catch syscall" command catches groups of related syscalls.
306 The "catch syscall" command now supports catching a group of related
307 syscalls using the 'group:' or 'g:' prefix.
312 skip -gfile file-glob-pattern
313 skip -function function
314 skip -rfunction regular-expression
315 A generalized form of the skip command, with new support for
316 glob-style file names and regular expressions for function names.
317 Additionally, a file spec and a function spec may now be combined.
319 maint info line-table REGEXP
320 Display the contents of GDB's internal line table data struture.
323 Run any GDB unit tests that were compiled in.
326 Start a new user interface instance running INTERP as interpreter,
327 using the TTY file for input/output.
331 ** gdb.Breakpoint objects have a new attribute "pending", which
332 indicates whether the breakpoint is pending.
333 ** Three new breakpoint-related events have been added:
334 gdb.breakpoint_created, gdb.breakpoint_modified, and
335 gdb.breakpoint_deleted.
338 Signal ("set") the given MS-Windows event object. This is used in
339 conjunction with the Windows JIT debugging (AeDebug) support, where
340 the OS suspends a crashing process until a debugger can attach to
341 it. Resuming the crashing process, in order to debug it, is done by
344 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
345 was added in GDBserver, including JIT compiling fast tracepoint's
346 conditional expression bytecode into native code.
348 * Support for various remote target protocols and ROM monitors has
351 target m32rsdi Remote M32R debugging over SDI
352 target mips MIPS remote debugging protocol
353 target pmon PMON ROM monitor
354 target ddb NEC's DDB variant of PMON for Vr4300
355 target rockhopper NEC RockHopper variant of PMON
356 target lsi LSI variant of PMO
358 * Support for tracepoints and fast tracepoints on powerpc-linux,
359 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
360 including JIT compiling fast tracepoint's conditional expression
361 bytecode into native code.
363 * MI async record =record-started now includes the method and format used for
364 recording. For example:
366 =record-started,thread-group="i1",method="btrace",format="bts"
368 * MI async record =thread-selected now includes the frame field. For example:
370 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
374 Andes NDS32 nds32*-*-elf
376 *** Changes in GDB 7.11
378 * GDB now supports debugging kernel-based threads on FreeBSD.
380 * Per-inferior thread numbers
382 Thread numbers are now per inferior instead of global. If you're
383 debugging multiple inferiors, GDB displays thread IDs using a
384 qualified INF_NUM.THR_NUM form. For example:
388 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
389 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
390 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
391 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
393 As consequence, thread numbers as visible in the $_thread
394 convenience variable and in Python's InferiorThread.num attribute
395 are no longer unique between inferiors.
397 GDB now maintains a second thread ID per thread, referred to as the
398 global thread ID, which is the new equivalent of thread numbers in
399 previous releases. See also $_gthread below.
401 For backwards compatibility, MI's thread IDs always refer to global
404 * Commands that accept thread IDs now accept the qualified
405 INF_NUM.THR_NUM form as well. For example:
408 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
411 * In commands that accept a list of thread IDs, you can now refer to
412 all threads of an inferior using a star wildcard. GDB accepts
413 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
414 refer to all threads of the current inferior. For example, "info
417 * You can use "info threads -gid" to display the global thread ID of
420 * The new convenience variable $_gthread holds the global number of
423 * The new convenience variable $_inferior holds the number of the
426 * GDB now displays the ID and name of the thread that hit a breakpoint
427 or received a signal, if your program is multi-threaded. For
430 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
431 Thread 1 "main" received signal SIGINT, Interrupt.
433 * Record btrace now supports non-stop mode.
435 * Support for tracepoints on aarch64-linux was added in GDBserver.
437 * The 'record instruction-history' command now indicates speculative execution
438 when using the Intel Processor Trace recording format.
440 * GDB now allows users to specify explicit locations, bypassing
441 the linespec parser. This feature is also available to GDB/MI
444 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
445 GDB now is able to debug both AArch64 applications and ARM applications
448 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
449 including JIT compiling fast tracepoint's conditional expression bytecode
452 * GDB now supports displaced stepping on AArch64 GNU/Linux.
454 * "info threads", "info inferiors", "info display", "info checkpoints"
455 and "maint info program-spaces" now list the corresponding items in
456 ascending ID order, for consistency with all other "info" commands.
458 * In Ada, the overloads selection menu has been enhanced to display the
459 parameter types and the return types for the matching overloaded subprograms.
463 maint set target-non-stop (on|off|auto)
464 maint show target-non-stop
465 Control whether GDB targets always operate in non-stop mode even if
466 "set non-stop" is "off". The default is "auto", meaning non-stop
467 mode is enabled if supported by the target.
469 maint set bfd-sharing
470 maint show bfd-sharing
471 Control the reuse of bfd objects.
475 Control display of debugging info regarding bfd caching.
479 Control display of debugging info regarding FreeBSD threads.
481 set remote multiprocess-extensions-packet
482 show remote multiprocess-extensions-packet
483 Set/show the use of the remote protocol multiprocess extensions.
485 set remote thread-events
486 show remote thread-events
487 Set/show the use of thread create/exit events.
489 set ada print-signatures on|off
490 show ada print-signatures"
491 Control whether parameter types and return types are displayed in overloads
492 selection menus. It is activaled (@code{on}) by default.
496 Controls the maximum size of memory, in bytes, that GDB will
497 allocate for value contents. Prevents incorrect programs from
498 causing GDB to allocate overly large buffers. Default is 64k.
500 * The "disassemble" command accepts a new modifier: /s.
501 It prints mixed source+disassembly like /m with two differences:
502 - disassembled instructions are now printed in program order, and
503 - and source for all relevant files is now printed.
504 The "/m" option is now considered deprecated: its "source-centric"
505 output hasn't proved useful in practice.
507 * The "record instruction-history" command accepts a new modifier: /s.
508 It behaves exactly like /m and prints mixed source+disassembly.
510 * The "set scheduler-locking" command supports a new mode "replay".
511 It behaves like "off" in record mode and like "on" in replay mode.
513 * Support for various ROM monitors has been removed:
515 target dbug dBUG ROM monitor for Motorola ColdFire
516 target picobug Motorola picobug monitor
517 target dink32 DINK32 ROM monitor for PowerPC
518 target m32r Renesas M32R/D ROM monitor
519 target mon2000 mon2000 ROM monitor
520 target ppcbug PPCBUG ROM monitor for PowerPC
522 * Support for reading/writing memory and extracting values on architectures
523 whose memory is addressable in units of any integral multiple of 8 bits.
528 Indicates that an exec system call was executed.
530 exec-events feature in qSupported
531 The qSupported packet allows GDB to request support for exec
532 events using the new 'gdbfeature' exec-event, and the qSupported
533 response can contain the corresponding 'stubfeature'. Set and
534 show commands can be used to display whether these features are enabled.
537 Equivalent to interrupting with the ^C character, but works in
540 thread created stop reason (T05 create:...)
541 Indicates that the thread was just created and is stopped at entry.
543 thread exit stop reply (w exitcode;tid)
544 Indicates that the thread has terminated.
547 Enables/disables thread create and exit event reporting. For
548 example, this is used in non-stop mode when GDB stops a set of
549 threads and synchronously waits for the their corresponding stop
550 replies. Without exit events, if one of the threads exits, GDB
551 would hang forever not knowing that it should no longer expect a
552 stop for that same thread.
555 Indicates that there are no resumed threads left in the target (all
556 threads are stopped). The remote stub reports support for this stop
557 reply to GDB's qSupported query.
560 Enables/disables catching syscalls from the inferior process.
561 The remote stub reports support for this packet to GDB's qSupported query.
563 syscall_entry stop reason
564 Indicates that a syscall was just called.
566 syscall_return stop reason
567 Indicates that a syscall just returned.
569 * Extended-remote exec events
571 ** GDB now has support for exec events on extended-remote Linux targets.
572 For such targets with Linux kernels 2.5.46 and later, this enables
573 follow-exec-mode and exec catchpoints.
575 set remote exec-event-feature-packet
576 show remote exec-event-feature-packet
577 Set/show the use of the remote exec event feature.
579 * Thread names in remote protocol
581 The reply to qXfer:threads:read may now include a name attribute for each
584 * Target remote mode fork and exec events
586 ** GDB now has support for fork and exec events on target remote mode
587 Linux targets. For such targets with Linux kernels 2.5.46 and later,
588 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
589 fork and exec catchpoints.
591 * Remote syscall events
593 ** GDB now has support for catch syscall on remote Linux targets,
594 currently enabled on x86/x86_64 architectures.
596 set remote catch-syscall-packet
597 show remote catch-syscall-packet
598 Set/show the use of the remote catch syscall feature.
602 ** The -var-set-format command now accepts the zero-hexadecimal
603 format. It outputs data in hexadecimal format with zero-padding on the
608 ** gdb.InferiorThread objects have a new attribute "global_num",
609 which refers to the thread's global thread ID. The existing
610 "num" attribute now refers to the thread's per-inferior number.
611 See "Per-inferior thread numbers" above.
612 ** gdb.InferiorThread objects have a new attribute "inferior", which
613 is the Inferior object the thread belongs to.
615 *** Changes in GDB 7.10
617 * Support for process record-replay and reverse debugging on aarch64*-linux*
618 targets has been added. GDB now supports recording of A64 instruction set
619 including advance SIMD instructions.
621 * Support for Sun's version of the "stabs" debug file format has been removed.
623 * GDB now honors the content of the file /proc/PID/coredump_filter
624 (PID is the process ID) on GNU/Linux systems. This file can be used
625 to specify the types of memory mappings that will be included in a
626 corefile. For more information, please refer to the manual page of
627 "core(5)". GDB also has a new command: "set use-coredump-filter
628 on|off". It allows to set whether GDB will read the content of the
629 /proc/PID/coredump_filter file when generating a corefile.
631 * The "info os" command on GNU/Linux can now display information on
633 "info os cpus" Listing of all cpus/cores on the system
635 * GDB has two new commands: "set serial parity odd|even|none" and
636 "show serial parity". These allows to set or show parity for the
639 * The "info source" command now displays the producer string if it was
640 present in the debug info. This typically includes the compiler version
641 and may include things like its command line arguments.
643 * The "info dll", an alias of the "info sharedlibrary" command,
644 is now available on all platforms.
646 * Directory names supplied to the "set sysroot" commands may be
647 prefixed with "target:" to tell GDB to access shared libraries from
648 the target system, be it local or remote. This replaces the prefix
649 "remote:". The default sysroot has been changed from "" to
650 "target:". "remote:" is automatically converted to "target:" for
651 backward compatibility.
653 * The system root specified by "set sysroot" will be prepended to the
654 filename of the main executable (if reported to GDB as absolute by
655 the operating system) when starting processes remotely, and when
656 attaching to already-running local or remote processes.
658 * GDB now supports automatic location and retrieval of executable
659 files from remote targets. Remote debugging can now be initiated
660 using only a "target remote" or "target extended-remote" command
661 (no "set sysroot" or "file" commands are required). See "New remote
664 * The "dump" command now supports verilog hex format.
666 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
668 * On GNU/Linux, GDB and gdbserver are now able to access executable
669 and shared library files without a "set sysroot" command when
670 attaching to processes running in different mount namespaces from
671 the debugger. This makes it possible to attach to processes in
672 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
673 See "New remote packets" below.
675 * The "tui reg" command now provides completion for all of the
676 available register groups, including target specific groups.
678 * The HISTSIZE environment variable is no longer read when determining
679 the size of GDB's command history. GDB now instead reads the dedicated
680 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
681 disables truncation of command history. Non-numeric values of GDBHISTSIZE
686 ** Memory ports can now be unbuffered.
690 ** gdb.Objfile objects have a new attribute "username",
691 which is the name of the objfile as specified by the user,
692 without, for example, resolving symlinks.
693 ** You can now write frame unwinders in Python.
694 ** gdb.Type objects have a new method "optimized_out",
695 returning optimized out gdb.Value instance of this type.
696 ** gdb.Value objects have new methods "reference_value" and
697 "const_value" which return a reference to the value and a
698 "const" version of the value respectively.
702 maint print symbol-cache
703 Print the contents of the symbol cache.
705 maint print symbol-cache-statistics
706 Print statistics of symbol cache usage.
708 maint flush-symbol-cache
709 Flush the contents of the symbol cache.
713 Start branch trace recording using Branch Trace Store (BTS) format.
716 Evaluate expression by using the compiler and print result.
720 Explicit commands for enabling and disabling tui mode.
723 set mpx bound on i386 and amd64
724 Support for bound table investigation on Intel MPX enabled applications.
728 Start branch trace recording using Intel Processor Trace format.
731 Print information about branch tracing internals.
733 maint btrace packet-history
734 Print the raw branch tracing data.
736 maint btrace clear-packet-history
737 Discard the stored raw branch tracing data.
740 Discard all branch tracing data. It will be fetched and processed
741 anew by the next "record" command.
746 Renamed from "set debug dwarf2-die".
748 Renamed from "show debug dwarf2-die".
751 Renamed from "set debug dwarf2-read".
752 show debug dwarf-read
753 Renamed from "show debug dwarf2-read".
755 maint set dwarf always-disassemble
756 Renamed from "maint set dwarf2 always-disassemble".
757 maint show dwarf always-disassemble
758 Renamed from "maint show dwarf2 always-disassemble".
760 maint set dwarf max-cache-age
761 Renamed from "maint set dwarf2 max-cache-age".
762 maint show dwarf max-cache-age
763 Renamed from "maint show dwarf2 max-cache-age".
766 show debug dwarf-line
767 Control display of debugging info regarding DWARF line processing.
771 Set the maximum number of candidates to be considered during
772 completion. The default value is 200. This limit allows GDB
773 to avoid generating large completion lists, the computation of
774 which can cause the debugger to become temporarily unresponsive.
776 set history remove-duplicates
777 show history remove-duplicates
778 Control the removal of duplicate history entries.
780 maint set symbol-cache-size
781 maint show symbol-cache-size
782 Control the size of the symbol cache.
784 set|show record btrace bts buffer-size
785 Set and show the size of the ring buffer used for branch tracing in
787 The obtained size may differ from the requested size. Use "info
788 record" to see the obtained buffer size.
790 set debug linux-namespaces
791 show debug linux-namespaces
792 Control display of debugging info regarding Linux namespaces.
794 set|show record btrace pt buffer-size
795 Set and show the size of the ring buffer used for branch tracing in
796 Intel Processor Trace format.
797 The obtained size may differ from the requested size. Use "info
798 record" to see the obtained buffer size.
800 maint set|show btrace pt skip-pad
801 Set and show whether PAD packets are skipped when computing the
804 * The command 'thread apply all' can now support new option '-ascending'
805 to call its specified command for all threads in ascending order.
807 * Python/Guile scripting
809 ** GDB now supports auto-loading of Python/Guile scripts contained in the
810 special section named `.debug_gdb_scripts'.
814 qXfer:btrace-conf:read
815 Return the branch trace configuration for the current thread.
817 Qbtrace-conf:bts:size
818 Set the requested ring buffer size for branch tracing in BTS format.
821 Enable Intel Procesor Trace-based branch tracing for the current
822 process. The remote stub reports support for this packet to GDB's
826 Set the requested ring buffer size for branch tracing in Intel Processor
830 Indicates a memory breakpoint instruction was executed, irrespective
831 of whether it was GDB that planted the breakpoint or the breakpoint
832 is hardcoded in the program. This is required for correct non-stop
836 Indicates the target stopped for a hardware breakpoint. This is
837 required for correct non-stop mode operation.
840 Return information about files on the remote system.
843 Return the full absolute name of the file that was executed to
844 create a process running on the remote system.
847 Select the filesystem on which vFile: operations with filename
848 arguments will operate. This is required for GDB to be able to
849 access files on remote targets where the remote stub does not
850 share a common filesystem with the inferior(s).
853 Indicates that a fork system call was executed.
856 Indicates that a vfork system call was executed.
858 vforkdone stop reason
859 Indicates that a vfork child of the specified process has executed
860 an exec or exit, allowing the vfork parent to resume execution.
862 fork-events and vfork-events features in qSupported
863 The qSupported packet allows GDB to request support for fork and
864 vfork events using new 'gdbfeatures' fork-events and vfork-events,
865 and the qSupported response can contain the corresponding
866 'stubfeatures'. Set and show commands can be used to display
867 whether these features are enabled.
869 * Extended-remote fork events
871 ** GDB now has support for fork events on extended-remote Linux
872 targets. For targets with Linux kernels 2.5.60 and later, this
873 enables follow-fork-mode and detach-on-fork for both fork and
874 vfork, as well as fork and vfork catchpoints.
876 * The info record command now shows the recording format and the
877 branch tracing configuration for the current thread when using
878 the btrace record target.
879 For the BTS format, it shows the ring buffer size.
881 * GDB now has support for DTrace USDT (Userland Static Defined
882 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
884 * GDB now supports access to vector registers on S/390 GNU/Linux
887 * Removed command line options
889 -xdb HP-UX XDB compatibility mode.
891 * Removed targets and native configurations
893 HP/PA running HP-UX hppa*-*-hpux*
894 Itanium running HP-UX ia64-*-hpux*
896 * New configure options
899 This configure option allows the user to build GDB with support for
900 Intel Processor Trace (default: auto). This requires libipt.
902 --with-libipt-prefix=PATH
903 Specify the path to the version of libipt that GDB should use.
904 $PATH/include should contain the intel-pt.h header and
905 $PATH/lib should contain the libipt.so library.
907 *** Changes in GDB 7.9.1
911 ** Xmethods can now specify a result type.
913 *** Changes in GDB 7.9
915 * GDB now supports hardware watchpoints on x86 GNU Hurd.
919 ** You can now access frame registers from Python scripts.
920 ** New attribute 'producer' for gdb.Symtab objects.
921 ** gdb.Objfile objects have a new attribute "progspace",
922 which is the gdb.Progspace object of the containing program space.
923 ** gdb.Objfile objects have a new attribute "owner".
924 ** gdb.Objfile objects have a new attribute "build_id",
925 which is the build ID generated when the file was built.
926 ** gdb.Objfile objects have a new method "add_separate_debug_file".
927 ** A new event "gdb.clear_objfiles" has been added, triggered when
928 selecting a new file to debug.
929 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
930 ** New function gdb.lookup_objfile.
932 New events which are triggered when GDB modifies the state of the
935 ** gdb.events.inferior_call_pre: Function call is about to be made.
936 ** gdb.events.inferior_call_post: Function call has just been made.
937 ** gdb.events.memory_changed: A memory location has been altered.
938 ** gdb.events.register_changed: A register has been altered.
940 * New Python-based convenience functions:
942 ** $_caller_is(name [, number_of_frames])
943 ** $_caller_matches(regexp [, number_of_frames])
944 ** $_any_caller_is(name [, number_of_frames])
945 ** $_any_caller_matches(regexp [, number_of_frames])
947 * GDB now supports the compilation and injection of source code into
948 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
949 to compile the source code to object code, and if successful, inject
950 and execute that code within the current context of the inferior.
951 Currently the C language is supported. The commands used to
952 interface with this new feature are:
954 compile code [-raw|-r] [--] [source code]
955 compile file [-raw|-r] filename
959 demangle [-l language] [--] name
960 Demangle "name" in the specified language, or the current language
961 if elided. This command is renamed from the "maint demangle" command.
962 The latter is kept as a no-op to avoid "maint demangle" being interpreted
963 as "maint demangler-warning".
965 queue-signal signal-name-or-number
966 Queue a signal to be delivered to the thread when it is resumed.
968 add-auto-load-scripts-directory directory
969 Add entries to the list of directories from which to load auto-loaded
972 maint print user-registers
973 List all currently available "user" registers.
975 compile code [-r|-raw] [--] [source code]
976 Compile, inject, and execute in the inferior the executable object
977 code produced by compiling the provided source code.
979 compile file [-r|-raw] filename
980 Compile and inject into the inferior the executable object code
981 produced by compiling the source code stored in the filename
984 * On resume, GDB now always passes the signal the program had stopped
985 for to the thread the signal was sent to, even if the user changed
986 threads before resuming. Previously GDB would often (but not
987 always) deliver the signal to the thread that happens to be current
990 * Conversely, the "signal" command now consistently delivers the
991 requested signal to the current thread. GDB now asks for
992 confirmation if the program had stopped for a signal and the user
993 switched threads meanwhile.
995 * "breakpoint always-inserted" modes "off" and "auto" merged.
997 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
998 won't remove breakpoints from the target until all threads stop,
999 even in non-stop mode. The "auto" mode has been removed, and "off"
1000 is now the default mode.
1004 set debug symbol-lookup
1005 show debug symbol-lookup
1006 Control display of debugging info regarding symbol lookup.
1010 ** The -list-thread-groups command outputs an exit-code field for
1011 inferiors that have exited.
1015 MIPS SDE mips*-sde*-elf*
1019 Support for these obsolete configurations has been removed.
1021 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1022 SGI Irix-5.x mips-*-irix5*
1023 SGI Irix-6.x mips-*-irix6*
1024 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1025 VAX running Ultrix vax-*-ultrix*
1027 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1028 and "assf"), have been removed. Use the "sharedlibrary" command, or
1029 its alias "share", instead.
1031 *** Changes in GDB 7.8
1033 * New command line options
1036 This is an alias for the --data-directory option.
1038 * GDB supports printing and modifying of variable length automatic arrays
1039 as specified in ISO C99.
1041 * The ARM simulator now supports instruction level tracing
1042 with or without disassembly.
1046 GDB now has support for scripting using Guile. Whether this is
1047 available is determined at configure time.
1048 Guile version 2.0 or greater is required.
1049 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1051 * New commands (for set/show, see "New options" below)
1055 Invoke CODE by passing it to the Guile interpreter.
1059 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1061 info auto-load guile-scripts [regexp]
1062 Print the list of automatically loaded Guile scripts.
1064 * The source command is now capable of sourcing Guile scripts.
1065 This feature is dependent on the debugger being built with Guile support.
1069 set print symbol-loading (off|brief|full)
1070 show print symbol-loading
1071 Control whether to print informational messages when loading symbol
1072 information for a file. The default is "full", but when debugging
1073 programs with large numbers of shared libraries the amount of output
1074 becomes less useful.
1076 set guile print-stack (none|message|full)
1077 show guile print-stack
1078 Show a stack trace when an error is encountered in a Guile script.
1080 set auto-load guile-scripts (on|off)
1081 show auto-load guile-scripts
1082 Control auto-loading of Guile script files.
1084 maint ada set ignore-descriptive-types (on|off)
1085 maint ada show ignore-descriptive-types
1086 Control whether the debugger should ignore descriptive types in Ada
1087 programs. The default is not to ignore the descriptive types. See
1088 the user manual for more details on descriptive types and the intended
1089 usage of this option.
1091 set auto-connect-native-target
1093 Control whether GDB is allowed to automatically connect to the
1094 native target for the run, attach, etc. commands when not connected
1095 to any target yet. See also "target native" below.
1097 set record btrace replay-memory-access (read-only|read-write)
1098 show record btrace replay-memory-access
1099 Control what memory accesses are allowed during replay.
1101 maint set target-async (on|off)
1102 maint show target-async
1103 This controls whether GDB targets operate in synchronous or
1104 asynchronous mode. Normally the default is asynchronous, if it is
1105 available; but this can be changed to more easily debug problems
1106 occurring only in synchronous mode.
1108 set mi-async (on|off)
1110 Control whether MI asynchronous mode is preferred. This supersedes
1111 "set target-async" of previous GDB versions.
1113 * "set target-async" is deprecated as a CLI option and is now an alias
1114 for "set mi-async" (only puts MI into async mode).
1116 * Background execution commands (e.g., "c&", "s&", etc.) are now
1117 possible ``out of the box'' if the target supports them. Previously
1118 the user would need to explicitly enable the possibility with the
1119 "set target-async on" command.
1121 * New features in the GDB remote stub, GDBserver
1123 ** New option --debug-format=option1[,option2,...] allows one to add
1124 additional text to each output. At present only timestamps
1125 are supported: --debug-format=timestamps.
1126 Timestamps can also be turned on with the
1127 "monitor set debug-format timestamps" command from GDB.
1129 * The 'record instruction-history' command now starts counting instructions
1130 at one. This also affects the instruction ranges reported by the
1131 'record function-call-history' command when given the /i modifier.
1133 * The command 'record function-call-history' supports a new modifier '/c' to
1134 indent the function names based on their call stack depth.
1135 The fields for the '/i' and '/l' modifier have been reordered.
1136 The source line range is now prefixed with 'at'.
1137 The instruction range is now prefixed with 'inst'.
1138 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1139 "record instruction-history" and "list" commands.
1141 * The ranges given as arguments to the 'record function-call-history' and
1142 'record instruction-history' commands are now inclusive.
1144 * The btrace record target now supports the 'record goto' command.
1145 For locations inside the execution trace, the back trace is computed
1146 based on the information stored in the execution trace.
1148 * The btrace record target supports limited reverse execution and replay.
1149 The target does not record data and therefore does not allow reading
1150 memory or registers.
1152 * The "catch syscall" command now works on s390*-linux* targets.
1154 * The "compare-sections" command is no longer specific to target
1155 remote. It now works with all targets.
1157 * All native targets are now consistently called "native".
1158 Consequently, the "target child", "target GNU", "target djgpp",
1159 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1160 commands have been replaced with "target native". The QNX/NTO port
1161 leaves the "procfs" target in place and adds a "native" target for
1162 consistency with other ports. The impact on users should be minimal
1163 as these commands previously either throwed an error, or were
1164 no-ops. The target's name is visible in the output of the following
1165 commands: "help target", "info target", "info files", "maint print
1168 * The "target native" command now connects to the native target. This
1169 can be used to launch native programs even when "set
1170 auto-connect-native-target" is set to off.
1172 * GDB now supports access to Intel MPX registers on GNU/Linux.
1174 * Support for Intel AVX-512 registers on GNU/Linux.
1175 Support displaying and modifying Intel AVX-512 registers
1176 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1178 * New remote packets
1180 qXfer:btrace:read's annex
1181 The qXfer:btrace:read packet supports a new annex 'delta' to read
1182 branch trace incrementally.
1186 ** Valid Python operations on gdb.Value objects representing
1187 structs/classes invoke the corresponding overloaded operators if
1189 ** New `Xmethods' feature in the Python API. Xmethods are
1190 additional methods or replacements for existing methods of a C++
1191 class. This feature is useful for those cases where a method
1192 defined in C++ source code could be inlined or optimized out by
1193 the compiler, making it unavailable to GDB.
1196 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1198 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1199 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1200 its alias "share", instead.
1202 * The commands "set remotebaud" and "show remotebaud" are no longer
1203 supported. Use "set serial baud" and "show serial baud" (respectively)
1208 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1209 target-async". The latter is left as a deprecated alias of the
1210 former for backward compatibility. If the target supports it,
1211 CLI background execution commands are now always possible by
1212 default, independently of whether the frontend stated a
1213 preference for asynchronous execution with "-gdb-set mi-async".
1214 Previously "-gdb-set target-async off" affected both MI execution
1215 commands and CLI execution commands.
1217 *** Changes in GDB 7.7
1219 * Improved support for process record-replay and reverse debugging on
1220 arm*-linux* targets. Support for thumb32 and syscall instruction
1221 recording has been added.
1223 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1225 * GDB now supports Fission DWP file format version 2.
1226 http://gcc.gnu.org/wiki/DebugFission
1228 * New convenience function "$_isvoid", to check whether an expression
1229 is void. A void expression is an expression where the type of the
1230 result is "void". For example, some convenience variables may be
1231 "void" when evaluated (e.g., "$_exitcode" before the execution of
1232 the program being debugged; or an undefined convenience variable).
1233 Another example, when calling a function whose return type is
1236 * The "maintenance print objfiles" command now takes an optional regexp.
1238 * The "catch syscall" command now works on arm*-linux* targets.
1240 * GDB now consistently shows "<not saved>" when printing values of
1241 registers the debug info indicates have not been saved in the frame
1242 and there's nowhere to retrieve them from
1243 (callee-saved/call-clobbered registers):
1248 (gdb) info registers rax
1251 Before, the former would print "<optimized out>", and the latter
1252 "*value not available*".
1254 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1259 ** Frame filters and frame decorators have been added.
1260 ** Temporary breakpoints are now supported.
1261 ** Line tables representation has been added.
1262 ** New attribute 'parent_type' for gdb.Field objects.
1263 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1264 ** New attribute 'name' for gdb.Type objects.
1268 Nios II ELF nios2*-*-elf
1269 Nios II GNU/Linux nios2*-*-linux
1270 Texas Instruments MSP430 msp430*-*-elf
1272 * Removed native configurations
1274 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1275 been removed. ELF variants of these configurations are kept supported.
1277 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1278 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1279 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1280 i[34567]86-*-openbsd3.[0-3]
1281 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1282 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1283 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1287 Like "catch throw", but catches a re-thrown exception.
1288 maint check-psymtabs
1289 Renamed from old "maint check-symtabs".
1291 Perform consistency checks on symtabs.
1292 maint expand-symtabs
1293 Expand symtabs matching an optional regexp.
1296 Display the details of GDB configure-time options.
1298 maint set|show per-command
1299 maint set|show per-command space
1300 maint set|show per-command time
1301 maint set|show per-command symtab
1302 Enable display of per-command gdb resource usage.
1304 remove-symbol-file FILENAME
1305 remove-symbol-file -a ADDRESS
1306 Remove a symbol file added via add-symbol-file. The file to remove
1307 can be identified by its filename or by an address that lies within
1308 the boundaries of this symbol file in memory.
1311 info exceptions REGEXP
1312 Display the list of Ada exceptions defined in the program being
1313 debugged. If provided, only the exceptions whose names match REGEXP
1318 set debug symfile off|on
1320 Control display of debugging info regarding reading symbol files and
1321 symbol tables within those files
1323 set print raw frame-arguments
1324 show print raw frame-arguments
1325 Set/show whether to print frame arguments in raw mode,
1326 disregarding any defined pretty-printers.
1328 set remote trace-status-packet
1329 show remote trace-status-packet
1330 Set/show the use of remote protocol qTStatus packet.
1334 Control display of debugging messages related to Nios II targets.
1338 Control whether target-assisted range stepping is enabled.
1340 set startup-with-shell
1341 show startup-with-shell
1342 Specifies whether Unix child processes are started via a shell or
1347 Use the target memory cache for accesses to the code segment. This
1348 improves performance of remote debugging (particularly disassembly).
1350 * You can now use a literal value 'unlimited' for options that
1351 interpret 0 or -1 as meaning "unlimited". E.g., "set
1352 trace-buffer-size unlimited" is now an alias for "set
1353 trace-buffer-size -1" and "set height unlimited" is now an alias for
1356 * The "set debug symtab-create" debugging option of GDB has been changed to
1357 accept a verbosity level. 0 means "off", 1 provides basic debugging
1358 output, and values of 2 or greater provides more verbose output.
1360 * New command-line options
1362 Display the details of GDB configure-time options.
1364 * The command 'tsave' can now support new option '-ctf' to save trace
1365 buffer in Common Trace Format.
1367 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1370 * GDB now implements the the C++ 'typeid' operator.
1372 * The new convenience variable $_exception holds the exception being
1373 thrown or caught at an exception-related catchpoint.
1375 * The exception-related catchpoints, like "catch throw", now accept a
1376 regular expression which can be used to filter exceptions by type.
1378 * The new convenience variable $_exitsignal is automatically set to
1379 the terminating signal number when the program being debugged dies
1380 due to an uncaught signal.
1384 ** All MI commands now accept an optional "--language" option.
1385 Support for this feature can be verified by using the "-list-features"
1386 command, which should contain "language-option".
1388 ** The new command -info-gdb-mi-command allows the user to determine
1389 whether a GDB/MI command is supported or not.
1391 ** The "^error" result record returned when trying to execute an undefined
1392 GDB/MI command now provides a variable named "code" whose content is the
1393 "undefined-command" error code. Support for this feature can be verified
1394 by using the "-list-features" command, which should contain
1395 "undefined-command-error-code".
1397 ** The -trace-save MI command can optionally save trace buffer in Common
1400 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1402 ** The command -data-list-register-values now accepts an optional
1403 "--skip-unavailable" option. When used, only the available registers
1406 ** The new command -trace-frame-collected dumps collected variables,
1407 computed expressions, tvars, memory and registers in a traceframe.
1409 ** The commands -stack-list-locals, -stack-list-arguments and
1410 -stack-list-variables now accept an option "--skip-unavailable".
1411 When used, only the available locals or arguments are displayed.
1413 ** The -exec-run command now accepts an optional "--start" option.
1414 When used, the command follows the same semantics as the "start"
1415 command, stopping the program's execution at the start of its
1416 main subprogram. Support for this feature can be verified using
1417 the "-list-features" command, which should contain
1418 "exec-run-start-option".
1420 ** The new commands -catch-assert and -catch-exceptions insert
1421 catchpoints stopping the program when Ada exceptions are raised.
1423 ** The new command -info-ada-exceptions provides the equivalent of
1424 the new "info exceptions" command.
1426 * New system-wide configuration scripts
1427 A GDB installation now provides scripts suitable for use as system-wide
1428 configuration scripts for the following systems:
1432 * GDB now supports target-assigned range stepping with remote targets.
1433 This improves the performance of stepping source lines by reducing
1434 the number of control packets from/to GDB. See "New remote packets"
1437 * GDB now understands the element 'tvar' in the XML traceframe info.
1438 It has the id of the collected trace state variables.
1440 * On S/390 targets that provide the transactional-execution feature,
1441 the program interruption transaction diagnostic block (TDB) is now
1442 represented as a number of additional "registers" in GDB.
1444 * New remote packets
1448 The vCont packet supports a new 'r' action, that tells the remote
1449 stub to step through an address range itself, without GDB
1450 involvemement at each single-step.
1452 qXfer:libraries-svr4:read's annex
1453 The previously unused annex of the qXfer:libraries-svr4:read packet
1454 is now used to support passing an argument list. The remote stub
1455 reports support for this argument list to GDB's qSupported query.
1456 The defined arguments are "start" and "prev", used to reduce work
1457 necessary for library list updating, resulting in significant
1460 * New features in the GDB remote stub, GDBserver
1462 ** GDBserver now supports target-assisted range stepping. Currently
1463 enabled on x86/x86_64 GNU/Linux targets.
1465 ** GDBserver now adds element 'tvar' in the XML in the reply to
1466 'qXfer:traceframe-info:read'. It has the id of the collected
1467 trace state variables.
1469 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1472 * New 'z' formatter for printing and examining memory, this displays the
1473 value as hexadecimal zero padded on the left to the size of the type.
1475 * GDB can now use Windows x64 unwinding data.
1477 * The "set remotebaud" command has been replaced by "set serial baud".
1478 Similarly, "show remotebaud" has been replaced by "show serial baud".
1479 The "set remotebaud" and "show remotebaud" commands are still available
1480 to provide backward compatibility with older versions of GDB.
1482 *** Changes in GDB 7.6
1484 * Target record has been renamed to record-full.
1485 Record/replay is now enabled with the "record full" command.
1486 This also affects settings that are associated with full record/replay
1487 that have been moved from "set/show record" to "set/show record full":
1489 set|show record full insn-number-max
1490 set|show record full stop-at-limit
1491 set|show record full memory-query
1493 * A new record target "record-btrace" has been added. The new target
1494 uses hardware support to record the control-flow of a process. It
1495 does not support replaying the execution, but it implements the
1496 below new commands for investigating the recorded execution log.
1497 This new recording method can be enabled using:
1501 The "record-btrace" target is only available on Intel Atom processors
1502 and requires a Linux kernel 2.6.32 or later.
1504 * Two new commands have been added for record/replay to give information
1505 about the recorded execution without having to replay the execution.
1506 The commands are only supported by "record btrace".
1508 record instruction-history prints the execution history at
1509 instruction granularity
1511 record function-call-history prints the execution history at
1512 function granularity
1514 * New native configurations
1516 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1517 FreeBSD/powerpc powerpc*-*-freebsd
1518 x86_64/Cygwin x86_64-*-cygwin*
1519 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1523 ARM AArch64 aarch64*-*-elf
1524 ARM AArch64 GNU/Linux aarch64*-*-linux
1525 Lynx 178 PowerPC powerpc-*-lynx*178
1526 x86_64/Cygwin x86_64-*-cygwin*
1527 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1529 * If the configured location of system.gdbinit file (as given by the
1530 --with-system-gdbinit option at configure time) is in the
1531 data-directory (as specified by --with-gdb-datadir at configure
1532 time) or in one of its subdirectories, then GDB will look for the
1533 system-wide init file in the directory specified by the
1534 --data-directory command-line option.
1536 * New command line options:
1538 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1539 other initialization files, unlike -nx which disables all of them.
1541 * Removed command line options
1543 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1546 * The 'ptype' and 'whatis' commands now accept an argument to control
1549 * 'info proc' now works on some core files.
1553 ** Vectors can be created with gdb.Type.vector.
1555 ** Python's atexit.register now works in GDB.
1557 ** Types can be pretty-printed via a Python API.
1559 ** Python 3 is now supported (in addition to Python 2.4 or later)
1561 ** New class gdb.Architecture exposes GDB's internal representation
1562 of architecture in the Python API.
1564 ** New method Frame.architecture returns the gdb.Architecture object
1565 corresponding to the frame's architecture.
1567 * New Python-based convenience functions:
1569 ** $_memeq(buf1, buf2, length)
1570 ** $_streq(str1, str2)
1572 ** $_regex(str, regex)
1574 * The 'cd' command now defaults to using '~' (the home directory) if not
1577 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1578 default for GCC since November 2000.
1580 * The command 'forward-search' can now be abbreviated as 'fo'.
1582 * The command 'info tracepoints' can now display 'installed on target'
1583 or 'not installed on target' for each non-pending location of tracepoint.
1585 * New configure options
1587 --enable-libmcheck/--disable-libmcheck
1588 By default, development versions are built with -lmcheck on hosts
1589 that support it, in order to help track memory corruption issues.
1590 Release versions, on the other hand, are built without -lmcheck
1591 by default. The --enable-libmcheck/--disable-libmcheck configure
1592 options allow the user to override that default.
1593 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1594 This configure option allows the user to build GDB with
1595 libbabeltrace using which GDB can read Common Trace Format data.
1597 * New commands (for set/show, see "New options" below)
1600 Catch signals. This is similar to "handle", but allows commands and
1601 conditions to be attached.
1604 List the BFDs known to GDB.
1606 python-interactive [command]
1608 Start a Python interactive prompt, or evaluate the optional command
1609 and print the result of expressions.
1612 "py" is a new alias for "python".
1614 enable type-printer [name]...
1615 disable type-printer [name]...
1616 Enable or disable type printers.
1620 ** For the Renesas Super-H architecture, the "regs" command has been removed
1621 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1626 set print type methods (on|off)
1627 show print type methods
1628 Control whether method declarations are displayed by "ptype".
1629 The default is to show them.
1631 set print type typedefs (on|off)
1632 show print type typedefs
1633 Control whether typedef definitions are displayed by "ptype".
1634 The default is to show them.
1636 set filename-display basename|relative|absolute
1637 show filename-display
1638 Control the way in which filenames is displayed.
1639 The default is "relative", which preserves previous behavior.
1641 set trace-buffer-size
1642 show trace-buffer-size
1643 Request target to change the size of trace buffer.
1645 set remote trace-buffer-size-packet auto|on|off
1646 show remote trace-buffer-size-packet
1647 Control the use of the remote protocol `QTBuffer:size' packet.
1651 Control display of debugging messages related to ARM AArch64.
1654 set debug coff-pe-read
1655 show debug coff-pe-read
1656 Control display of debugging messages related to reading of COFF/PE
1661 Control display of debugging messages related to Mach-O symbols
1664 set debug notification
1665 show debug notification
1666 Control display of debugging info for async remote notification.
1670 ** Command parameter changes are now notified using new async record
1671 "=cmd-param-changed".
1672 ** Trace frame changes caused by command "tfind" are now notified using
1673 new async record "=traceframe-changed".
1674 ** The creation, deletion and modification of trace state variables
1675 are now notified using new async records "=tsv-created",
1676 "=tsv-deleted" and "=tsv-modified".
1677 ** The start and stop of process record are now notified using new
1678 async record "=record-started" and "=record-stopped".
1679 ** Memory changes are now notified using new async record
1681 ** The data-disassemble command response will include a "fullname" field
1682 containing the absolute file name when source has been requested.
1683 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1684 command, to allow pattern filling of memory areas.
1685 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1686 library load/unload events.
1687 ** The response to breakpoint commands and breakpoint async records
1688 includes an "installed" field containing a boolean state about each
1689 non-pending tracepoint location is whether installed on target or not.
1690 ** Output of the "-trace-status" command includes a "trace-file" field
1691 containing the name of the trace file being examined. This field is
1692 optional, and only present when examining a trace file.
1693 ** The "fullname" field is now always present along with the "file" field,
1694 even if the file cannot be found by GDB.
1696 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1697 You must have the LZMA library available when configuring GDB for this
1698 feature to be enabled. For more information, see:
1699 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1701 * New remote packets
1704 Set the size of trace buffer. The remote stub reports support for this
1705 packet to gdb's qSupported query.
1708 Enable Branch Trace Store (BTS)-based branch tracing for the current
1709 thread. The remote stub reports support for this packet to gdb's
1713 Disable branch tracing for the current thread. The remote stub reports
1714 support for this packet to gdb's qSupported query.
1717 Read the traced branches for the current thread. The remote stub
1718 reports support for this packet to gdb's qSupported query.
1720 *** Changes in GDB 7.5
1722 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1723 for more x32 ABI info.
1725 * GDB now supports access to MIPS DSP registers on Linux targets.
1727 * GDB now supports debugging microMIPS binaries.
1729 * The "info os" command on GNU/Linux can now display information on
1730 several new classes of objects managed by the operating system:
1731 "info os procgroups" lists process groups
1732 "info os files" lists file descriptors
1733 "info os sockets" lists internet-domain sockets
1734 "info os shm" lists shared-memory regions
1735 "info os semaphores" lists semaphores
1736 "info os msg" lists message queues
1737 "info os modules" lists loaded kernel modules
1739 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1740 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1741 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1742 options and inspect the probe arguments using the new $_probe_arg family
1743 of convenience variables. You can obtain more information about SystemTap
1744 in <http://sourceware.org/systemtap/>.
1746 * GDB now supports reversible debugging on ARM, it allows you to
1747 debug basic ARM and THUMB instructions, and provides
1748 record/replay support.
1750 * The option "symbol-reloading" has been deleted as it is no longer used.
1754 ** GDB commands implemented in Python can now be put in command class
1757 ** The "maint set python print-stack on|off" is now deleted.
1759 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1760 apply "flag enum"-style pretty-printing to any enum.
1762 ** gdb.lookup_symbol can now work when there is no current frame.
1764 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1765 the source at which the symbol was defined.
1767 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1768 method 'value'. The former indicates whether the symbol needs a
1769 frame in order to compute its value, and the latter computes the
1772 ** A new method 'referenced_value' on gdb.Value objects which can
1773 dereference pointer as well as C++ reference values.
1775 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1776 which return the global and static blocks (as gdb.Block objects),
1777 of the underlying symbol table, respectively.
1779 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1780 object associated with a PC value.
1782 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1783 of the address range occupied by code for the current source line.
1785 * Go language support.
1786 GDB now supports debugging programs written in the Go programming
1789 * GDBserver now supports stdio connections.
1790 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1792 * The binary "gdbtui" can no longer be built or installed.
1793 Use "gdb -tui" instead.
1795 * GDB will now print "flag" enums specially. A flag enum is one where
1796 all the enumerator values have no bits in common when pairwise
1797 "and"ed. When printing a value whose type is a flag enum, GDB will
1798 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1799 (gdb) print (enum E) 3
1802 * The filename part of a linespec will now match trailing components
1803 of a source file name. For example, "break gcc/expr.c:1000" will
1804 now set a breakpoint in build/gcc/expr.c, but not
1805 build/libcpp/expr.c.
1807 * The "info proc" and "generate-core-file" commands will now also
1808 work on remote targets connected to GDBserver on Linux.
1810 * The command "info catch" has been removed. It has been disabled
1811 since December 2007.
1813 * The "catch exception" and "catch assert" commands now accept
1814 a condition at the end of the command, much like the "break"
1815 command does. For instance:
1817 (gdb) catch exception Constraint_Error if Barrier = True
1819 Previously, it was possible to add a condition to such catchpoints,
1820 but it had to be done as a second step, after the catchpoint had been
1821 created, using the "condition" command.
1823 * The "info static-tracepoint-marker" command will now also work on
1824 native Linux targets with in-process agent.
1826 * GDB can now set breakpoints on inlined functions.
1828 * The .gdb_index section has been updated to include symbols for
1829 inlined functions. GDB will ignore older .gdb_index sections by
1830 default, which could cause symbol files to be loaded more slowly
1831 until their .gdb_index sections can be recreated. The new command
1832 "set use-deprecated-index-sections on" will cause GDB to use any older
1833 .gdb_index sections it finds. This will restore performance, but the
1834 ability to set breakpoints on inlined functions will be lost in symbol
1835 files with older .gdb_index sections.
1837 The .gdb_index section has also been updated to record more information
1838 about each symbol. This speeds up the "info variables", "info functions"
1839 and "info types" commands when used with programs having the .gdb_index
1840 section, as well as speeding up debugging with shared libraries using
1841 the .gdb_index section.
1843 * Ada support for GDB/MI Variable Objects has been added.
1845 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1850 ** New command -info-os is the MI equivalent of "info os".
1852 ** Output logs ("set logging" and related) now include MI output.
1856 ** "set use-deprecated-index-sections on|off"
1857 "show use-deprecated-index-sections on|off"
1858 Controls the use of deprecated .gdb_index sections.
1860 ** "catch load" and "catch unload" can be used to stop when a shared
1861 library is loaded or unloaded, respectively.
1863 ** "enable count" can be used to auto-disable a breakpoint after
1866 ** "info vtbl" can be used to show the virtual method tables for
1867 C++ and Java objects.
1869 ** "explore" and its sub commands "explore value" and "explore type"
1870 can be used to recursively explore values and types of
1871 expressions. These commands are available only if GDB is
1872 configured with '--with-python'.
1874 ** "info auto-load" shows status of all kinds of auto-loaded files,
1875 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
1876 sequences of commands files, "info auto-load python-scripts"
1877 shows status of auto-loading Python script files,
1878 "info auto-load local-gdbinit" shows status of loading init file
1879 (.gdbinit) from current directory and "info auto-load libthread-db" shows
1880 status of inferior specific thread debugging shared library loading.
1882 ** "info auto-load-scripts", "set auto-load-scripts on|off"
1883 and "show auto-load-scripts" commands have been deprecated, use their
1884 "info auto-load python-scripts", "set auto-load python-scripts on|off"
1885 and "show auto-load python-scripts" counterparts instead.
1887 ** "dprintf location,format,args..." creates a dynamic printf, which
1888 is basically a breakpoint that does a printf and immediately
1889 resumes your program's execution, so it is like a printf that you
1890 can insert dynamically at runtime instead of at compiletime.
1892 ** "set print symbol"
1894 Controls whether GDB attempts to display the symbol, if any,
1895 corresponding to addresses it prints. This defaults to "on", but
1896 you can set it to "off" to restore GDB's previous behavior.
1898 * Deprecated commands
1900 ** For the Renesas Super-H architecture, the "regs" command has been
1901 deprecated, and "info all-registers" should be used instead.
1905 Renesas RL78 rl78-*-elf
1906 HP OpenVMS ia64 ia64-hp-openvms*
1908 * GDBserver supports evaluation of breakpoint conditions. When
1909 support is advertised by GDBserver, GDB may be told to send the
1910 breakpoint conditions in bytecode form to GDBserver. GDBserver
1911 will only report the breakpoint trigger to GDB when its condition
1916 set mips compression
1917 show mips compression
1918 Select the compressed ISA encoding used in functions that have no symbol
1919 information available. The encoding can be set to either of:
1922 and is updated automatically from ELF file flags if available.
1924 set breakpoint condition-evaluation
1925 show breakpoint condition-evaluation
1926 Control whether breakpoint conditions are evaluated by GDB ("host") or by
1927 GDBserver ("target"). Default option "auto" chooses the most efficient
1929 This option can improve debugger efficiency depending on the speed of the
1933 Disable auto-loading globally.
1936 Show auto-loading setting of all kinds of auto-loaded files.
1938 set auto-load gdb-scripts on|off
1939 show auto-load gdb-scripts
1940 Control auto-loading of GDB canned sequences of commands files.
1942 set auto-load python-scripts on|off
1943 show auto-load python-scripts
1944 Control auto-loading of Python script files.
1946 set auto-load local-gdbinit on|off
1947 show auto-load local-gdbinit
1948 Control loading of init file (.gdbinit) from current directory.
1950 set auto-load libthread-db on|off
1951 show auto-load libthread-db
1952 Control auto-loading of inferior specific thread debugging shared library.
1954 set auto-load scripts-directory <dir1>[:<dir2>...]
1955 show auto-load scripts-directory
1956 Set a list of directories from which to load auto-loaded scripts.
1957 Automatically loaded Python scripts and GDB scripts are located in one
1958 of the directories listed by this option.
1959 The delimiter (':' above) may differ according to the host platform.
1961 set auto-load safe-path <dir1>[:<dir2>...]
1962 show auto-load safe-path
1963 Set a list of directories from which it is safe to auto-load files.
1964 The delimiter (':' above) may differ according to the host platform.
1966 set debug auto-load on|off
1967 show debug auto-load
1968 Control display of debugging info for auto-loading the files above.
1970 set dprintf-style gdb|call|agent
1972 Control the way in which a dynamic printf is performed; "gdb"
1973 requests a GDB printf command, while "call" causes dprintf to call a
1974 function in the inferior. "agent" requests that the target agent
1975 (such as GDBserver) do the printing.
1977 set dprintf-function <expr>
1978 show dprintf-function
1979 set dprintf-channel <expr>
1980 show dprintf-channel
1981 Set the function and optional first argument to the call when using
1982 the "call" style of dynamic printf.
1984 set disconnected-dprintf on|off
1985 show disconnected-dprintf
1986 Control whether agent-style dynamic printfs continue to be in effect
1987 after GDB disconnects.
1989 * New configure options
1991 --with-auto-load-dir
1992 Configure default value for the 'set auto-load scripts-directory'
1993 setting above. It defaults to '$debugdir:$datadir/auto-load',
1994 $debugdir representing global debugging info directories (available
1995 via 'show debug-file-directory') and $datadir representing GDB's data
1996 directory (available via 'show data-directory').
1998 --with-auto-load-safe-path
1999 Configure default value for the 'set auto-load safe-path' setting
2000 above. It defaults to the --with-auto-load-dir setting.
2002 --without-auto-load-safe-path
2003 Set 'set auto-load safe-path' to '/', effectively disabling this
2006 * New remote packets
2008 z0/z1 conditional breakpoints extension
2010 The z0/z1 breakpoint insertion packets have been extended to carry
2011 a list of conditional expressions over to the remote stub depending on the
2012 condition evaluation mode. The use of this extension can be controlled
2013 via the "set remote conditional-breakpoints-packet" command.
2017 Specify the signals which the remote stub may pass to the debugged
2018 program without GDB involvement.
2020 * New command line options
2022 --init-command=FILE, -ix Like --command, -x but execute it
2023 before loading inferior.
2024 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2025 execute it before loading inferior.
2027 *** Changes in GDB 7.4
2029 * GDB now handles ambiguous linespecs more consistently; the existing
2030 FILE:LINE support has been expanded to other types of linespecs. A
2031 breakpoint will now be set on all matching locations in all
2032 inferiors, and locations will be added or removed according to
2035 * GDB now allows you to skip uninteresting functions and files when
2036 stepping with the "skip function" and "skip file" commands.
2038 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2039 and "show remote hardware-watchpoint-length-limit". These allows to
2040 set or show the maximum length limit (in bytes) of a remote
2041 target hardware watchpoint.
2043 This allows e.g. to use "unlimited" hardware watchpoints with the
2044 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2045 watchpoints are slower than real hardware watchpoints but are
2046 significantly faster than gdb software watchpoints.
2050 ** The register_pretty_printer function in module gdb.printing now takes
2051 an optional `replace' argument. If True, the new printer replaces any
2054 ** The "maint set python print-stack on|off" command has been
2055 deprecated and will be deleted in GDB 7.5.
2056 A new command: "set python print-stack none|full|message" has
2057 replaced it. Additionally, the default for "print-stack" is
2058 now "message", which just prints the error message without
2061 ** A prompt substitution hook (prompt_hook) is now available to the
2064 ** A new Python module, gdb.prompt has been added to the GDB Python
2065 modules library. This module provides functionality for
2066 escape sequences in prompts (used by set/show
2067 extended-prompt). These escape sequences are replaced by their
2068 corresponding value.
2070 ** Python commands and convenience-functions located in
2071 'data-directory'/python/gdb/command and
2072 'data-directory'/python/gdb/function are now automatically loaded
2075 ** Blocks now provide four new attributes. global_block and
2076 static_block will return the global and static blocks
2077 respectively. is_static and is_global are boolean attributes
2078 that indicate if the block is one of those two types.
2080 ** Symbols now provide the "type" attribute, the type of the symbol.
2082 ** The "gdb.breakpoint" function has been deprecated in favor of
2085 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2086 of a function. This class is based on the "finish" command
2087 available in the CLI.
2089 ** Type objects for struct and union types now allow access to
2090 the fields using standard Python dictionary (mapping) methods.
2091 For example, "some_type['myfield']" now works, as does
2092 "some_type.items()".
2094 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2097 ** A new function, "deep_items" has been added to the gdb.types
2098 module in the GDB Python modules library. This function returns
2099 an iterator over the fields of a struct or union type. Unlike
2100 the standard Python "iteritems" method, it will recursively traverse
2101 any anonymous fields.
2105 ** "*stopped" events can report several new "reason"s, such as
2108 ** Breakpoint changes are now notified using new async records, like
2109 "=breakpoint-modified".
2111 ** New command -ada-task-info.
2113 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2114 $sdir specifies the default system locations of shared libraries.
2115 $pdir specifies the directory where the libpthread used by the application
2118 GDB no longer looks in $sdir and $pdir after it has searched the directories
2119 mentioned in libthread-db-search-path. If you want to search those
2120 directories, they must be specified in libthread-db-search-path.
2121 The default value of libthread-db-search-path on GNU/Linux and Solaris
2122 systems is now "$sdir:$pdir".
2124 $pdir is not supported by gdbserver, it is currently ignored.
2125 $sdir is supported by gdbserver.
2127 * New configure option --with-iconv-bin.
2128 When using the internationalization support like the one in the GNU C
2129 library, GDB will invoke the "iconv" program to get a list of supported
2130 character sets. If this program lives in a non-standard location, one can
2131 use this option to specify where to find it.
2133 * When natively debugging programs on PowerPC BookE processors running
2134 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2135 watchpoints, which specify a mask in addition to an address to watch.
2136 The mask specifies that some bits of an address (the bits which are
2137 reset in the mask) should be ignored when matching the address accessed
2138 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2139 section in the user manual for more details.
2141 * The new option --once causes GDBserver to stop listening for connections once
2142 the first connection is made. The listening port used by GDBserver will
2143 become available after that.
2145 * New commands "info macros" and "alias" have been added.
2147 * New function parameters suffix @entry specifies value of function parameter
2148 at the time the function got called. Entry values are available only since
2154 "!" is now an alias of the "shell" command.
2155 Note that no space is needed between "!" and SHELL COMMAND.
2159 watch EXPRESSION mask MASK_VALUE
2160 The watch command now supports the mask argument which allows creation
2161 of masked watchpoints, if the current architecture supports this feature.
2163 info auto-load-scripts [REGEXP]
2164 This command was formerly named "maintenance print section-scripts".
2165 It is now generally useful and is no longer a maintenance-only command.
2167 info macro [-all] [--] MACRO
2168 The info macro command has new options `-all' and `--'. The first for
2169 printing all definitions of a macro. The second for explicitly specifying
2170 the end of arguments and the beginning of the macro name in case the macro
2171 name starts with a hyphen.
2173 collect[/s] EXPRESSIONS
2174 The tracepoint collect command now takes an optional modifier "/s"
2175 that directs it to dereference pointer-to-character types and
2176 collect the bytes of memory up to a zero byte. The behavior is
2177 similar to what you see when you use the regular print command on a
2178 string. An optional integer following the "/s" sets a bound on the
2179 number of bytes that will be collected.
2182 The trace start command now interprets any supplied arguments as a
2183 note to be recorded with the trace run, with an effect similar to
2184 setting the variable trace-notes.
2187 The trace stop command now interprets any arguments as a note to be
2188 mentioned along with the tstatus report that the trace was stopped
2189 with a command. The effect is similar to setting the variable
2192 * Tracepoints can now be enabled and disabled at any time after a trace
2193 experiment has been started using the standard "enable" and "disable"
2194 commands. It is now possible to start a trace experiment with no enabled
2195 tracepoints; GDB will display a warning, but will allow the experiment to
2196 begin, assuming that tracepoints will be enabled as needed while the trace
2199 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2200 locations with 4-byte instructions, when they were previously
2201 limited to locations with instructions of 5 bytes or longer.
2205 set debug dwarf2-read
2206 show debug dwarf2-read
2207 Turns on or off display of debugging messages related to reading
2208 DWARF debug info. The default is off.
2210 set debug symtab-create
2211 show debug symtab-create
2212 Turns on or off display of debugging messages related to symbol table
2213 creation. The default is off.
2216 show extended-prompt
2217 Set the GDB prompt, and allow escape sequences to be inserted to
2218 display miscellaneous information (see 'help set extended-prompt'
2219 for the list of sequences). This prompt (and any information
2220 accessed through the escape sequences) is updated every time the
2221 prompt is displayed.
2223 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2224 show print entry-values
2225 Set printing of frame argument values at function entry. In some cases
2226 GDB can determine the value of function argument which was passed by the
2227 function caller, even if the value was modified inside the called function.
2229 set debug entry-values
2230 show debug entry-values
2231 Control display of debugging info for determining frame argument values at
2232 function entry and virtual tail call frames.
2234 set basenames-may-differ
2235 show basenames-may-differ
2236 Set whether a source file may have multiple base names.
2237 (A "base name" is the name of a file with the directory part removed.
2238 Example: The base name of "/home/user/hello.c" is "hello.c".)
2239 If set, GDB will canonicalize file names (e.g., expand symlinks)
2240 before comparing them. Canonicalization is an expensive operation,
2241 but it allows the same file be known by more than one base name.
2242 If not set (the default), all source files are assumed to have just
2243 one base name, and gdb will do file name comparisons more efficiently.
2249 Set a user name and notes for the current and any future trace runs.
2250 This is useful for long-running and/or disconnected traces, to
2251 inform others (or yourself) as to who is running the trace, supply
2252 contact information, or otherwise explain what is going on.
2254 set trace-stop-notes
2255 show trace-stop-notes
2256 Set a note attached to the trace run, that is displayed when the
2257 trace has been stopped by a tstop command. This is useful for
2258 instance as an explanation, if you are stopping a trace run that was
2259 started by someone else.
2261 * New remote packets
2265 Dynamically enable a tracepoint in a started trace experiment.
2269 Dynamically disable a tracepoint in a started trace experiment.
2273 Set the user and notes of the trace run.
2277 Query the current status of a tracepoint.
2281 Query the minimum length of instruction at which a fast tracepoint may
2284 * Dcache size (number of lines) and line-size are now runtime-configurable
2285 via "set dcache line" and "set dcache line-size" commands.
2289 Texas Instruments TMS320C6x tic6x-*-*
2293 Renesas RL78 rl78-*-elf
2295 *** Changes in GDB 7.3.1
2297 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2299 *** Changes in GDB 7.3
2301 * GDB has a new command: "thread find [REGEXP]".
2302 It finds the thread id whose name, target id, or thread extra info
2303 matches the given regular expression.
2305 * The "catch syscall" command now works on mips*-linux* targets.
2307 * The -data-disassemble MI command now supports modes 2 and 3 for
2308 dumping the instruction opcodes.
2310 * New command line options
2312 -data-directory DIR Specify DIR as the "data-directory".
2313 This is mostly for testing purposes.
2315 * The "maint set python auto-load on|off" command has been renamed to
2316 "set auto-load-scripts on|off".
2318 * GDB has a new command: "set directories".
2319 It is like the "dir" command except that it replaces the
2320 source path list instead of augmenting it.
2322 * GDB now understands thread names.
2324 On GNU/Linux, "info threads" will display the thread name as set by
2325 prctl or pthread_setname_np.
2327 There is also a new command, "thread name", which can be used to
2328 assign a name internally for GDB to display.
2331 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2332 has been integrated into GDB.
2336 ** The function gdb.Write now accepts an optional keyword 'stream'.
2337 This keyword, when provided, will direct the output to either
2338 stdout, stderr, or GDB's logging output.
2340 ** Parameters can now be be sub-classed in Python, and in particular
2341 you may implement the get_set_doc and get_show_doc functions.
2342 This improves how Parameter set/show documentation is processed
2343 and allows for more dynamic content.
2345 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2346 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2347 have an is_valid method.
2349 ** Breakpoints can now be sub-classed in Python, and in particular
2350 you may implement a 'stop' function that is executed each time
2351 the inferior reaches that breakpoint.
2353 ** New function gdb.lookup_global_symbol looks up a global symbol.
2355 ** GDB values in Python are now callable if the value represents a
2356 function. For example, if 'some_value' represents a function that
2357 takes two integer parameters and returns a value, you can call
2358 that function like so:
2360 result = some_value (10,20)
2362 ** Module gdb.types has been added.
2363 It contains a collection of utilities for working with gdb.Types objects:
2364 get_basic_type, has_field, make_enum_dict.
2366 ** Module gdb.printing has been added.
2367 It contains utilities for writing and registering pretty-printers.
2368 New classes: PrettyPrinter, SubPrettyPrinter,
2369 RegexpCollectionPrettyPrinter.
2370 New function: register_pretty_printer.
2372 ** New commands "info pretty-printers", "enable pretty-printer" and
2373 "disable pretty-printer" have been added.
2375 ** gdb.parameter("directories") is now available.
2377 ** New function gdb.newest_frame returns the newest frame in the
2380 ** The gdb.InferiorThread class has a new "name" attribute. This
2381 holds the thread's name.
2383 ** Python Support for Inferior events.
2384 Python scripts can add observers to be notified of events
2385 occurring in the process being debugged.
2386 The following events are currently supported:
2387 - gdb.events.cont Continue event.
2388 - gdb.events.exited Inferior exited event.
2389 - gdb.events.stop Signal received, and Breakpoint hit events.
2393 ** GDB now puts template parameters in scope when debugging in an
2394 instantiation. For example, if you have:
2396 template<int X> int func (void) { return X; }
2398 then if you step into func<5>, "print X" will show "5". This
2399 feature requires proper debuginfo support from the compiler; it
2400 was added to GCC 4.5.
2402 ** The motion commands "next", "finish", "until", and "advance" now
2403 work better when exceptions are thrown. In particular, GDB will
2404 no longer lose control of the inferior; instead, the GDB will
2405 stop the inferior at the point at which the exception is caught.
2406 This functionality requires a change in the exception handling
2407 code that was introduced in GCC 4.5.
2409 * GDB now follows GCC's rules on accessing volatile objects when
2410 reading or writing target state during expression evaluation.
2411 One notable difference to prior behavior is that "print x = 0"
2412 no longer generates a read of x; the value of the assignment is
2413 now always taken directly from the value being assigned.
2415 * GDB now has some support for using labels in the program's source in
2416 linespecs. For instance, you can use "advance label" to continue
2417 execution to a label.
2419 * GDB now has support for reading and writing a new .gdb_index
2420 section. This section holds a fast index of DWARF debugging
2421 information and can be used to greatly speed up GDB startup and
2422 operation. See the documentation for `save gdb-index' for details.
2424 * The "watch" command now accepts an optional "-location" argument.
2425 When used, this causes GDB to watch the memory referred to by the
2426 expression. Such a watchpoint is never deleted due to it going out
2429 * GDB now supports thread debugging of core dumps on GNU/Linux.
2431 GDB now activates thread debugging using the libthread_db library
2432 when debugging GNU/Linux core dumps, similarly to when debugging
2433 live processes. As a result, when debugging a core dump file, GDB
2434 is now able to display pthread_t ids of threads. For example, "info
2435 threads" shows the same output as when debugging the process when it
2436 was live. In earlier releases, you'd see something like this:
2439 * 1 LWP 6780 main () at main.c:10
2441 While now you see this:
2444 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2446 It is also now possible to inspect TLS variables when debugging core
2449 When debugging a core dump generated on a machine other than the one
2450 used to run GDB, you may need to point GDB at the correct
2451 libthread_db library with the "set libthread-db-search-path"
2452 command. See the user manual for more details on this command.
2454 * When natively debugging programs on PowerPC BookE processors running
2455 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2456 which stop execution of the inferior whenever it executes an instruction
2457 at any address within the specified range. See the "PowerPC Embedded"
2458 section in the user manual for more details.
2460 * New features in the GDB remote stub, GDBserver
2462 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2463 and i686 LynxOS (version 5.x).
2465 ** GDBserver is now supported on Blackfin Linux.
2467 * New native configurations
2469 ia64 HP-UX ia64-*-hpux*
2473 Analog Devices, Inc. Blackfin Processor bfin-*
2475 * Ada task switching is now supported on sparc-elf targets when
2476 debugging a program using the Ravenscar Profile. For more information,
2477 see the "Tasking Support when using the Ravenscar Profile" section
2478 in the GDB user manual.
2480 * Guile support was removed.
2482 * New features in the GNU simulator
2484 ** The --map-info flag lists all known core mappings.
2486 ** CFI flashes may be simulated via the "cfi" device.
2488 *** Changes in GDB 7.2
2490 * Shared library support for remote targets by default
2492 When GDB is configured for a generic, non-OS specific target, like
2493 for example, --target=arm-eabi or one of the many *-*-elf targets,
2494 GDB now queries remote stubs for loaded shared libraries using the
2495 `qXfer:libraries:read' packet. Previously, shared library support
2496 was always disabled for such configurations.
2500 ** Argument Dependent Lookup (ADL)
2502 In C++ ADL lookup directs function search to the namespaces of its
2503 arguments even if the namespace has not been imported.
2513 Here the compiler will search for `foo' in the namespace of 'b'
2514 and find A::foo. GDB now supports this. This construct is commonly
2515 used in the Standard Template Library for operators.
2517 ** Improved User Defined Operator Support
2519 In addition to member operators, GDB now supports lookup of operators
2520 defined in a namespace and imported with a `using' directive, operators
2521 defined in the global scope, operators imported implicitly from an
2522 anonymous namespace, and the ADL operators mentioned in the previous
2524 GDB now also supports proper overload resolution for all the previously
2525 mentioned flavors of operators.
2527 ** static const class members
2529 Printing of static const class members that are initialized in the
2530 class definition has been fixed.
2532 * Windows Thread Information Block access.
2534 On Windows targets, GDB now supports displaying the Windows Thread
2535 Information Block (TIB) structure. This structure is visible either
2536 by using the new command `info w32 thread-information-block' or, by
2537 dereferencing the new convenience variable named `$_tlb', a
2538 thread-specific pointer to the TIB. This feature is also supported
2539 when remote debugging using GDBserver.
2541 * Static tracepoints
2543 Static tracepoints are calls in the user program into a tracing
2544 library. One such library is a port of the LTTng kernel tracer to
2545 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2546 When debugging with GDBserver, GDB now supports combining the GDB
2547 tracepoint machinery with such libraries. For example: the user can
2548 use GDB to probe a static tracepoint marker (a call from the user
2549 program into the tracing library) with the new "strace" command (see
2550 "New commands" below). This creates a "static tracepoint" in the
2551 breakpoint list, that can be manipulated with the same feature set
2552 as fast and regular tracepoints. E.g., collect registers, local and
2553 global variables, collect trace state variables, and define
2554 tracepoint conditions. In addition, the user can collect extra
2555 static tracepoint marker specific data, by collecting the new
2556 $_sdata internal variable. When analyzing the trace buffer, you can
2557 inspect $_sdata like any other variable available to GDB. For more
2558 information, see the "Tracepoints" chapter in GDB user manual. New
2559 remote packets have been defined to support static tracepoints, see
2560 the "New remote packets" section below.
2562 * Better reconstruction of tracepoints after disconnected tracing
2564 GDB will attempt to download the original source form of tracepoint
2565 definitions when starting a trace run, and then will upload these
2566 upon reconnection to the target, resulting in a more accurate
2567 reconstruction of the tracepoints that are in use on the target.
2571 You can now exercise direct control over the ways that GDB can
2572 affect your program. For instance, you can disallow the setting of
2573 breakpoints, so that the program can run continuously (assuming
2574 non-stop mode). In addition, the "observer" variable is available
2575 to switch all of the different controls; in observer mode, GDB
2576 cannot affect the target's behavior at all, which is useful for
2577 tasks like diagnosing live systems in the field.
2579 * The new convenience variable $_thread holds the number of the
2582 * New remote packets
2586 Return the address of the Windows Thread Information Block of a given thread.
2590 In response to several of the tracepoint packets, the target may now
2591 also respond with a number of intermediate `qRelocInsn' request
2592 packets before the final result packet, to have GDB handle
2593 relocating an instruction to execute at a different address. This
2594 is particularly useful for stubs that support fast tracepoints. GDB
2595 reports support for this feature in the qSupported packet.
2599 List static tracepoint markers in the target program.
2603 List static tracepoint markers at a given address in the target
2606 qXfer:statictrace:read
2608 Read the static trace data collected (by a `collect $_sdata'
2609 tracepoint action). The remote stub reports support for this packet
2610 to gdb's qSupported query.
2614 Send the current settings of GDB's permission flags.
2618 Send part of the source (textual) form of a tracepoint definition,
2619 which includes location, conditional, and action list.
2621 * The source command now accepts a -s option to force searching for the
2622 script in the source search path even if the script name specifies
2625 * New features in the GDB remote stub, GDBserver
2627 - GDBserver now support tracepoints (including fast tracepoints, and
2628 static tracepoints). The feature is currently supported by the
2629 i386-linux and amd64-linux builds. See the "Tracepoints support
2630 in gdbserver" section in the manual for more information.
2632 GDBserver JIT compiles the tracepoint's conditional agent
2633 expression bytecode into native code whenever possible for low
2634 overhead dynamic tracepoints conditionals. For such tracepoints,
2635 an expression that examines program state is evaluated when the
2636 tracepoint is reached, in order to determine whether to capture
2637 trace data. If the condition is simple and false, processing the
2638 tracepoint finishes very quickly and no data is gathered.
2640 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2641 for static tracepoints support.
2643 - GDBserver now supports x86_64 Windows 64-bit debugging.
2645 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2646 it understands register description.
2648 * The --batch flag now disables pagination and queries.
2650 * X86 general purpose registers
2652 GDB now supports reading/writing byte, word and double-word x86
2653 general purpose registers directly. This means you can use, say,
2654 $ah or $ax to refer, respectively, to the byte register AH and
2655 16-bit word register AX that are actually portions of the 32-bit
2656 register EAX or 64-bit register RAX.
2658 * The `commands' command now accepts a range of breakpoints to modify.
2659 A plain `commands' following a command that creates multiple
2660 breakpoints affects all the breakpoints set by that command. This
2661 applies to breakpoints set by `rbreak', and also applies when a
2662 single `break' command creates multiple breakpoints (e.g.,
2663 breakpoints on overloaded c++ functions).
2665 * The `rbreak' command now accepts a filename specification as part of
2666 its argument, limiting the functions selected by the regex to those
2667 in the specified file.
2669 * Support for remote debugging Windows and SymbianOS shared libraries
2670 from Unix hosts has been improved. Non Windows GDB builds now can
2671 understand target reported file names that follow MS-DOS based file
2672 system semantics, such as file names that include drive letters and
2673 use the backslash character as directory separator. This makes it
2674 possible to transparently use the "set sysroot" and "set
2675 solib-search-path" on Unix hosts to point as host copies of the
2676 target's shared libraries. See the new command "set
2677 target-file-system-kind" described below, and the "Commands to
2678 specify files" section in the user manual for more information.
2682 eval template, expressions...
2683 Convert the values of one or more expressions under the control
2684 of the string template to a command line, and call it.
2686 set target-file-system-kind unix|dos-based|auto
2687 show target-file-system-kind
2688 Set or show the assumed file system kind for target reported file
2691 save breakpoints <filename>
2692 Save all current breakpoint definitions to a file suitable for use
2693 in a later debugging session. To read the saved breakpoint
2694 definitions, use the `source' command.
2696 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2699 info static-tracepoint-markers
2700 Display information about static tracepoint markers in the target.
2702 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2703 Define a static tracepoint by probing a marker at the given
2704 function, line, address, or marker ID.
2708 Enable and disable observer mode.
2710 set may-write-registers on|off
2711 set may-write-memory on|off
2712 set may-insert-breakpoints on|off
2713 set may-insert-tracepoints on|off
2714 set may-insert-fast-tracepoints on|off
2715 set may-interrupt on|off
2716 Set individual permissions for GDB effects on the target. Note that
2717 some of these settings can have undesirable or surprising
2718 consequences, particularly when changed in the middle of a session.
2719 For instance, disabling the writing of memory can prevent
2720 breakpoints from being inserted, cause single-stepping to fail, or
2721 even crash your program, if you disable after breakpoints have been
2722 inserted. However, GDB should not crash.
2724 set record memory-query on|off
2725 show record memory-query
2726 Control whether to stop the inferior if memory changes caused
2727 by an instruction cannot be recorded.
2732 The disassemble command now supports "start,+length" form of two arguments.
2736 ** GDB now provides a new directory location, called the python directory,
2737 where Python scripts written for GDB can be installed. The location
2738 of that directory is <data-directory>/python, where <data-directory>
2739 is the GDB data directory. For more details, see section `Scripting
2740 GDB using Python' in the manual.
2742 ** The GDB Python API now has access to breakpoints, symbols, symbol
2743 tables, program spaces, inferiors, threads and frame's code blocks.
2744 Additionally, GDB Parameters can now be created from the API, and
2745 manipulated via set/show in the CLI.
2747 ** New functions gdb.target_charset, gdb.target_wide_charset,
2748 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2750 ** New exception gdb.GdbError.
2752 ** Pretty-printers are now also looked up in the current program space.
2754 ** Pretty-printers can now be individually enabled and disabled.
2756 ** GDB now looks for names of Python scripts to auto-load in a
2757 special section named `.debug_gdb_scripts', in addition to looking
2758 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2760 * Tracepoint actions were unified with breakpoint commands. In particular,
2761 there are no longer differences in "info break" output for breakpoints and
2762 tracepoints and the "commands" command can be used for both tracepoints and
2763 regular breakpoints.
2767 ARM Symbian arm*-*-symbianelf*
2769 * D language support.
2770 GDB now supports debugging programs written in the D programming
2773 * GDB now supports the extended ptrace interface for PowerPC which is
2774 available since Linux kernel version 2.6.34. This automatically enables
2775 any hardware breakpoints and additional hardware watchpoints available in
2776 the processor. The old ptrace interface exposes just one hardware
2777 watchpoint and no hardware breakpoints.
2779 * GDB is now able to use the Data Value Compare (DVC) register available on
2780 embedded PowerPC processors to implement in hardware simple watchpoint
2781 conditions of the form:
2783 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2785 This works in native GDB running on Linux kernels with the extended ptrace
2786 interface mentioned above.
2788 *** Changes in GDB 7.1
2792 ** Namespace Support
2794 GDB now supports importing of namespaces in C++. This enables the
2795 user to inspect variables from imported namespaces. Support for
2796 namepace aliasing has also been added. So, if a namespace is
2797 aliased in the current scope (e.g. namepace C=A; ) the user can
2798 print variables using the alias (e.g. (gdb) print C::x).
2802 All known bugs relating to the printing of virtual base class were
2803 fixed. It is now possible to call overloaded static methods using a
2808 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2809 and reinterpret_cast<> are now handled by the C++ expression parser.
2813 Xilinx MicroBlaze microblaze-*-*
2818 Xilinx MicroBlaze microblaze
2821 * Multi-program debugging.
2823 GDB now has support for multi-program (a.k.a. multi-executable or
2824 multi-exec) debugging. This allows for debugging multiple inferiors
2825 simultaneously each running a different program under the same GDB
2826 session. See "Debugging Multiple Inferiors and Programs" in the
2827 manual for more information. This implied some user visible changes
2828 in the multi-inferior support. For example, "info inferiors" now
2829 lists inferiors that are not running yet or that have exited
2830 already. See also "New commands" and "New options" below.
2832 * New tracing features
2834 GDB's tracepoint facility now includes several new features:
2836 ** Trace state variables
2838 GDB tracepoints now include support for trace state variables, which
2839 are variables managed by the target agent during a tracing
2840 experiment. They are useful for tracepoints that trigger each
2841 other, so for instance one tracepoint can count hits in a variable,
2842 and then a second tracepoint has a condition that is true when the
2843 count reaches a particular value. Trace state variables share the
2844 $-syntax of GDB convenience variables, and can appear in both
2845 tracepoint actions and condition expressions. Use the "tvariable"
2846 command to create, and "info tvariables" to view; see "Trace State
2847 Variables" in the manual for more detail.
2851 GDB now includes an option for defining fast tracepoints, which
2852 targets may implement more efficiently, such as by installing a jump
2853 into the target agent rather than a trap instruction. The resulting
2854 speedup can be by two orders of magnitude or more, although the
2855 tradeoff is that some program locations on some target architectures
2856 might not allow fast tracepoint installation, for instance if the
2857 instruction to be replaced is shorter than the jump. To request a
2858 fast tracepoint, use the "ftrace" command, with syntax identical to
2859 the regular trace command.
2861 ** Disconnected tracing
2863 It is now possible to detach GDB from the target while it is running
2864 a trace experiment, then reconnect later to see how the experiment
2865 is going. In addition, a new variable disconnected-tracing lets you
2866 tell the target agent whether to continue running a trace if the
2867 connection is lost unexpectedly.
2871 GDB now has the ability to save the trace buffer into a file, and
2872 then use that file as a target, similarly to you can do with
2873 corefiles. You can select trace frames, print data that was
2874 collected in them, and use tstatus to display the state of the
2875 tracing run at the moment that it was saved. To create a trace
2876 file, use "tsave <filename>", and to use it, do "target tfile
2879 ** Circular trace buffer
2881 You can ask the target agent to handle the trace buffer as a
2882 circular buffer, discarding the oldest trace frames to make room for
2883 newer ones, by setting circular-trace-buffer to on. This feature may
2884 not be available for all target agents.
2889 The disassemble command, when invoked with two arguments, now requires
2890 the arguments to be comma-separated.
2893 The info variables command now displays variable definitions. Files
2894 which only declare a variable are not shown.
2897 The source command is now capable of sourcing Python scripts.
2898 This feature is dependent on the debugger being build with Python
2901 Related to this enhancement is also the introduction of a new command
2902 "set script-extension" (see below).
2904 * New commands (for set/show, see "New options" below)
2906 record save [<FILENAME>]
2907 Save a file (in core file format) containing the process record
2908 execution log for replay debugging at a later time.
2910 record restore <FILENAME>
2911 Restore the process record execution log that was saved at an
2912 earlier time, for replay debugging.
2914 add-inferior [-copies <N>] [-exec <FILENAME>]
2917 clone-inferior [-copies <N>] [ID]
2918 Make a new inferior ready to execute the same program another
2919 inferior has loaded.
2924 maint info program-spaces
2925 List the program spaces loaded into GDB.
2927 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
2928 show remote interrupt-sequence
2929 Allow the user to select one of ^C, a BREAK signal or BREAK-g
2930 as the sequence to the remote target in order to interrupt the execution.
2931 Ctrl-C is a default. Some system prefers BREAK which is high level of
2932 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
2933 Magic SysRq g. It is BREAK signal and character 'g'.
2935 set remote interrupt-on-connect [on | off]
2936 show remote interrupt-on-connect
2937 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
2938 remote target when gdb connects to it. This is needed when you debug
2941 set remotebreak [on | off]
2943 Deprecated. Use "set/show remote interrupt-sequence" instead.
2945 tvariable $NAME [ = EXP ]
2946 Create or modify a trace state variable.
2949 List trace state variables and their values.
2951 delete tvariable $NAME ...
2952 Delete one or more trace state variables.
2955 Evaluate the given expressions without collecting anything into the
2956 trace buffer. (Valid in tracepoint actions only.)
2958 ftrace FN / FILE:LINE / *ADDR
2959 Define a fast tracepoint at the given function, line, or address.
2961 * New expression syntax
2963 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
2964 GDB now parses 0b101010 identically with 42.
2968 set follow-exec-mode new|same
2969 show follow-exec-mode
2970 Control whether GDB reuses the same inferior across an exec call or
2971 creates a new one. This is useful to be able to restart the old
2972 executable after the inferior having done an exec call.
2974 set default-collect EXPR, ...
2975 show default-collect
2976 Define a list of expressions to be collected at each tracepoint.
2977 This is a useful way to ensure essential items are not overlooked,
2978 such as registers or a critical global variable.
2980 set disconnected-tracing
2981 show disconnected-tracing
2982 If set to 1, the target is instructed to continue tracing if it
2983 loses its connection to GDB. If 0, the target is to stop tracing
2986 set circular-trace-buffer
2987 show circular-trace-buffer
2988 If set to on, the target is instructed to use a circular trace buffer
2989 and discard the oldest trace frames instead of stopping the trace due
2990 to a full trace buffer. If set to off, the trace stops when the buffer
2991 fills up. Some targets may not support this.
2993 set script-extension off|soft|strict
2994 show script-extension
2995 If set to "off", the debugger does not perform any script language
2996 recognition, and all sourced files are assumed to be GDB scripts.
2997 If set to "soft" (the default), files are sourced according to
2998 filename extension, falling back to GDB scripts if the first
3000 If set to "strict", files are sourced according to filename extension.
3002 set ada trust-PAD-over-XVS on|off
3003 show ada trust-PAD-over-XVS
3004 If off, activate a workaround against a bug in the debugging information
3005 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3006 the GCC sources for more information about the GNAT encoding and
3007 PAD types in particular). It is always safe to set this option to
3008 off, but this introduces a slight performance penalty. The default
3011 * Python API Improvements
3013 ** GDB provides the new class gdb.LazyString. This is useful in
3014 some pretty-printing cases. The new method gdb.Value.lazy_string
3015 provides a simple way to create objects of this type.
3017 ** The fields returned by gdb.Type.fields now have an
3018 `is_base_class' attribute.
3020 ** The new method gdb.Type.range returns the range of an array type.
3022 ** The new method gdb.parse_and_eval can be used to parse and
3023 evaluate an expression.
3025 * New remote packets
3028 Define a trace state variable.
3031 Get the current value of a trace state variable.
3034 Set desired tracing behavior upon disconnection.
3037 Set the trace buffer to be linear or circular.
3040 Get data about the tracepoints currently in use.
3044 Process record now works correctly with hardware watchpoints.
3046 Multiple bug fixes have been made to the mips-irix port, making it
3047 much more reliable. In particular:
3048 - Debugging threaded applications is now possible again. Previously,
3049 GDB would hang while starting the program, or while waiting for
3050 the program to stop at a breakpoint.
3051 - Attaching to a running process no longer hangs.
3052 - An error occurring while loading a core file has been fixed.
3053 - Changing the value of the PC register now works again. This fixes
3054 problems observed when using the "jump" command, or when calling
3055 a function from GDB, or even when assigning a new value to $pc.
3056 - With the "finish" and "return" commands, the return value for functions
3057 returning a small array is now correctly printed.
3058 - It is now possible to break on shared library code which gets executed
3059 during a shared library init phase (code executed while executing
3060 their .init section). Previously, the breakpoint would have no effect.
3061 - GDB is now able to backtrace through the signal handler for
3062 non-threaded programs.
3064 PIE (Position Independent Executable) programs debugging is now supported.
3065 This includes debugging execution of PIC (Position Independent Code) shared
3066 libraries although for that, it should be possible to run such libraries as an
3069 *** Changes in GDB 7.0
3071 * GDB now has an interface for JIT compilation. Applications that
3072 dynamically generate code can create symbol files in memory and register
3073 them with GDB. For users, the feature should work transparently, and
3074 for JIT developers, the interface is documented in the GDB manual in the
3075 "JIT Compilation Interface" chapter.
3077 * Tracepoints may now be conditional. The syntax is as for
3078 breakpoints; either an "if" clause appended to the "trace" command,
3079 or the "condition" command is available. GDB sends the condition to
3080 the target for evaluation using the same bytecode format as is used
3081 for tracepoint actions.
3083 * The disassemble command now supports: an optional /r modifier, print the
3084 raw instructions in hex as well as in symbolic form, and an optional /m
3085 modifier to print mixed source+assembly.
3087 * Process record and replay
3089 In a architecture environment that supports ``process record and
3090 replay'', ``process record and replay'' target can record a log of
3091 the process execution, and replay it with both forward and reverse
3094 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3095 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3096 set execution-direction {forward|reverse}, for targets that support
3099 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3100 feature is available with a native GDB running on kernel version
3103 * GDB now has support for multi-byte and wide character sets on the
3104 target. Strings whose character type is wchar_t, char16_t, or
3105 char32_t are now correctly printed. GDB supports wide- and unicode-
3106 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3107 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3108 `printf'. This feature requires iconv to work properly; if your
3109 system does not have a working iconv, GDB can use GNU libiconv. See
3110 the installation instructions for more information.
3112 * GDB now supports automatic retrieval of shared library files from
3113 remote targets. To use this feature, specify a system root that begins
3114 with the `remote:' prefix, either via the `set sysroot' command or via
3115 the `--with-sysroot' configure-time option.
3117 * "info sharedlibrary" now takes an optional regex of libraries to show,
3118 and it now reports if a shared library has no debugging information.
3120 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3121 now complete on file names.
3123 * When completing in expressions, gdb will attempt to limit
3124 completions to allowable structure or union fields, where appropriate.
3125 For instance, consider:
3127 # struct example { int f1; double f2; };
3128 # struct example variable;
3131 If the user types TAB at the end of this command line, the available
3132 completions will be "f1" and "f2".
3134 * Inlined functions are now supported. They show up in backtraces, and
3135 the "step", "next", and "finish" commands handle them automatically.
3137 * GDB now supports the token-splicing (##) and stringification (#)
3138 operators when expanding macros. It also supports variable-arity
3141 * GDB now supports inspecting extra signal information, exported by
3142 the new $_siginfo convenience variable. The feature is currently
3143 implemented on linux ARM, i386 and amd64.
3145 * GDB can now display the VFP floating point registers and NEON vector
3146 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3147 can provide these registers (requires Linux 2.6.30 or later). Remote
3148 and simulator targets may also provide them.
3150 * New remote packets
3153 Search memory for a sequence of bytes.
3156 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3157 operation over reliable transport links. Use of this packet is
3158 controlled by the `set remote noack-packet' command.
3161 Kill the process with the specified process ID. Use this in preference
3162 to `k' when multiprocess protocol extensions are supported.
3165 Obtains additional operating system information
3169 Read or write additional signal information.
3171 * Removed remote protocol undocumented extension
3173 An undocumented extension to the remote protocol's `S' stop reply
3174 packet that permited the stub to pass a process id was removed.
3175 Remote servers should use the `T' stop reply packet instead.
3177 * GDB now supports multiple function calling conventions according to the
3178 DWARF-2 DW_AT_calling_convention function attribute.
3180 * The SH target utilizes the aforementioned change to distinguish between gcc
3181 and Renesas calling convention. It also adds the new CLI commands
3182 `set/show sh calling-convention'.
3184 * GDB can now read compressed debug sections, as produced by GNU gold
3185 with the --compress-debug-sections=zlib flag.
3187 * 64-bit core files are now supported on AIX.
3189 * Thread switching is now supported on Tru64.
3191 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3192 which will be allocated using malloc later in program execution.
3194 * The qXfer:libraries:read remote procotol packet now allows passing a
3195 list of section offsets.
3197 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3198 conditions handling signals delivered during attach or thread creation
3199 have also been fixed.
3201 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3202 From the user's standpoint, all unqualified instances of True and False
3203 are treated as the standard definitions, regardless of context.
3205 * GDB now parses C++ symbol and type names more flexibly. For
3208 template<typename T> class C { };
3211 GDB will now correctly handle all of:
3213 ptype C<char const *>
3214 ptype C<char const*>
3215 ptype C<const char *>
3216 ptype C<const char*>
3218 * New features in the GDB remote stub, gdbserver
3220 - The "--wrapper" command-line argument tells gdbserver to use a
3221 wrapper program to launch programs for debugging.
3223 - On PowerPC and S/390 targets, it is now possible to use a single
3224 gdbserver executable to debug both 32-bit and 64-bit programs.
3225 (This requires gdbserver itself to be built as a 64-bit executable.)
3227 - gdbserver uses the new noack protocol mode for TCP connections to
3228 reduce communications latency, if also supported and enabled in GDB.
3230 - Support for the sparc64-linux-gnu target is now included in
3233 - The amd64-linux build of gdbserver now supports debugging both
3234 32-bit and 64-bit programs.
3236 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3237 now support hardware watchpoints, and will use them automatically
3242 GDB now has support for scripting using Python. Whether this is
3243 available is determined at configure time.
3245 New GDB commands can now be written in Python.
3247 * Ada tasking support
3249 Ada tasks can now be inspected in GDB. The following commands have
3253 Print the list of Ada tasks.
3255 Print detailed information about task number N.
3257 Print the task number of the current task.
3259 Switch the context of debugging to task number N.
3261 * Support for user-defined prefixed commands. The "define" command can
3262 add new commands to existing prefixes, e.g. "target".
3264 * Multi-inferior, multi-process debugging.
3266 GDB now has generalized support for multi-inferior debugging. See
3267 "Debugging Multiple Inferiors" in the manual for more information.
3268 Although availability still depends on target support, the command
3269 set is more uniform now. The GNU/Linux specific multi-forks support
3270 has been migrated to this new framework. This implied some user
3271 visible changes; see "New commands" and also "Removed commands"
3274 * Target descriptions can now describe the target OS ABI. See the
3275 "Target Description Format" section in the user manual for more
3278 * Target descriptions can now describe "compatible" architectures
3279 to indicate that the target can execute applications for a different
3280 architecture in addition to those for the main target architecture.
3281 See the "Target Description Format" section in the user manual for
3284 * Multi-architecture debugging.
3286 GDB now includes general supports for debugging applications on
3287 hybrid systems that use more than one single processor architecture
3288 at the same time. Each such hybrid architecture still requires
3289 specific support to be added. The only hybrid architecture supported
3290 in this version of GDB is the Cell Broadband Engine.
3292 * GDB now supports integrated debugging of Cell/B.E. applications that
3293 use both the PPU and SPU architectures. To enable support for hybrid
3294 Cell/B.E. debugging, you need to configure GDB to support both the
3295 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3296 --enable-targets configure option.
3298 * Non-stop mode debugging.
3300 For some targets, GDB now supports an optional mode of operation in
3301 which you can examine stopped threads while other threads continue
3302 to execute freely. This is referred to as non-stop mode, with the
3303 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3304 section in the user manual for more information.
3306 To be able to support remote non-stop debugging, a remote stub needs
3307 to implement the non-stop mode remote protocol extensions, as
3308 described in the "Remote Non-Stop" section of the user manual. The
3309 GDB remote stub, gdbserver, has been adjusted to support these
3310 extensions on linux targets.
3312 * New commands (for set/show, see "New options" below)
3314 catch syscall [NAME(S) | NUMBER(S)]
3315 Catch system calls. Arguments, which should be names of system
3316 calls or their numbers, mean catch only those syscalls. Without
3317 arguments, every syscall will be caught. When the inferior issues
3318 any of the specified syscalls, GDB will stop and announce the system
3319 call, both when it is called and when its call returns. This
3320 feature is currently available with a native GDB running on the
3321 Linux Kernel, under the following architectures: x86, x86_64,
3322 PowerPC and PowerPC64.
3324 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3326 Search memory for a sequence of bytes.
3328 maint set python print-stack
3329 maint show python print-stack
3330 Show a stack trace when an error is encountered in a Python script.
3333 Invoke CODE by passing it to the Python interpreter.
3338 These allow macros to be defined, undefined, and listed
3342 Show operating system information about processes.
3345 List the inferiors currently under GDB's control.
3348 Switch focus to inferior number NUM.
3351 Detach from inferior number NUM.
3354 Kill inferior number NUM.
3358 set spu stop-on-load
3359 show spu stop-on-load
3360 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3362 set spu auto-flush-cache
3363 show spu auto-flush-cache
3364 Control whether to automatically flush the software-managed cache
3365 during Cell/B.E. debugging.
3367 set sh calling-convention
3368 show sh calling-convention
3369 Control the calling convention used when calling SH target functions.
3372 show debug timestamp
3373 Control display of timestamps with GDB debugging output.
3375 set disassemble-next-line
3376 show disassemble-next-line
3377 Control display of disassembled source lines or instructions when
3380 set remote noack-packet
3381 show remote noack-packet
3382 Set/show the use of remote protocol QStartNoAckMode packet. See above
3383 under "New remote packets."
3385 set remote query-attached-packet
3386 show remote query-attached-packet
3387 Control use of remote protocol `qAttached' (query-attached) packet.
3389 set remote read-siginfo-object
3390 show remote read-siginfo-object
3391 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3394 set remote write-siginfo-object
3395 show remote write-siginfo-object
3396 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3399 set remote reverse-continue
3400 show remote reverse-continue
3401 Control use of remote protocol 'bc' (reverse-continue) packet.
3403 set remote reverse-step
3404 show remote reverse-step
3405 Control use of remote protocol 'bs' (reverse-step) packet.
3407 set displaced-stepping
3408 show displaced-stepping
3409 Control displaced stepping mode. Displaced stepping is a way to
3410 single-step over breakpoints without removing them from the debuggee.
3411 Also known as "out-of-line single-stepping".
3414 show debug displaced
3415 Control display of debugging info for displaced stepping.
3417 maint set internal-error
3418 maint show internal-error
3419 Control what GDB does when an internal error is detected.
3421 maint set internal-warning
3422 maint show internal-warning
3423 Control what GDB does when an internal warning is detected.
3428 Use a wrapper program to launch programs for debugging.
3430 set multiple-symbols (all|ask|cancel)
3431 show multiple-symbols
3432 The value of this variable can be changed to adjust the debugger behavior
3433 when an expression or a breakpoint location contains an ambiguous symbol
3434 name (an overloaded function name, for instance).
3436 set breakpoint always-inserted
3437 show breakpoint always-inserted
3438 Keep breakpoints always inserted in the target, as opposed to inserting
3439 them when resuming the target, and removing them when the target stops.
3440 This option can improve debugger performance on slow remote targets.
3442 set arm fallback-mode (arm|thumb|auto)
3443 show arm fallback-mode
3444 set arm force-mode (arm|thumb|auto)
3446 These commands control how ARM GDB determines whether instructions
3447 are ARM or Thumb. The default for both settings is auto, which uses
3448 the current CPSR value for instructions without symbols; previous
3449 versions of GDB behaved as if "set arm fallback-mode arm".
3451 set disable-randomization
3452 show disable-randomization
3453 Standalone programs run with the virtual address space randomization enabled
3454 by default on some platforms. This option keeps the addresses stable across
3455 multiple debugging sessions.
3459 Control whether other threads are stopped or not when some thread hits
3464 Requests that asynchronous execution is enabled in the target, if available.
3465 In this case, it's possible to resume target in the background, and interact
3466 with GDB while the target is running. "show target-async" displays the
3467 current state of asynchronous execution of the target.
3469 set target-wide-charset
3470 show target-wide-charset
3471 The target-wide-charset is the name of the character set that GDB
3472 uses when printing characters whose type is wchar_t.
3474 set tcp auto-retry (on|off)
3476 set tcp connect-timeout
3477 show tcp connect-timeout
3478 These commands allow GDB to retry failed TCP connections to a remote stub
3479 with a specified timeout period; this is useful if the stub is launched
3480 in parallel with GDB but may not be ready to accept connections immediately.
3482 set libthread-db-search-path
3483 show libthread-db-search-path
3484 Control list of directories which GDB will search for appropriate
3487 set schedule-multiple (on|off)
3488 show schedule-multiple
3489 Allow GDB to resume all threads of all processes or only threads of
3490 the current process.
3494 Use more aggressive caching for accesses to the stack. This improves
3495 performance of remote debugging (particularly backtraces) without
3496 affecting correctness.
3498 set interactive-mode (on|off|auto)
3499 show interactive-mode
3500 Control whether GDB runs in interactive mode (on) or not (off).
3501 When in interactive mode, GDB waits for the user to answer all
3502 queries. Otherwise, GDB does not wait and assumes the default
3503 answer. When set to auto (the default), GDB determines which
3504 mode to use based on the stdin settings.
3509 For program forks, this is replaced by the new more generic `info
3510 inferiors' command. To list checkpoints, you can still use the
3511 `info checkpoints' command, which was an alias for the `info forks'
3515 Replaced by the new `inferior' command. To switch between
3516 checkpoints, you can still use the `restart' command, which was an
3517 alias for the `fork' command.
3520 This is removed, since some targets don't have a notion of
3521 processes. To switch between processes, you can still use the
3522 `inferior' command using GDB's own inferior number.
3525 For program forks, this is replaced by the new more generic `kill
3526 inferior' command. To delete a checkpoint, you can still use the
3527 `delete checkpoint' command, which was an alias for the `delete
3531 For program forks, this is replaced by the new more generic `detach
3532 inferior' command. To detach a checkpoint, you can still use the
3533 `detach checkpoint' command, which was an alias for the `detach
3536 * New native configurations
3538 x86/x86_64 Darwin i[34567]86-*-darwin*
3540 x86_64 MinGW x86_64-*-mingw*
3544 Lattice Mico32 lm32-*
3545 x86 DICOS i[34567]86-*-dicos*
3546 x86_64 DICOS x86_64-*-dicos*
3549 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3550 (mingw32ce) debugging.
3556 These commands were actually not implemented on any target.
3558 *** Changes in GDB 6.8
3560 * New native configurations
3562 NetBSD/hppa hppa*-*netbsd*
3563 Xtensa GNU/Linux xtensa*-*-linux*
3567 NetBSD/hppa hppa*-*-netbsd*
3568 Xtensa GNU/Lunux xtensa*-*-linux*
3570 * Change in command line behavior -- corefiles vs. process ids.
3572 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3573 attaching to process NUMBER fails, GDB no longer attempts to open a
3574 core file named NUMBER. Attaching to a program using the -c option
3575 is no longer supported. Instead, use the '-p' or '--pid' options.
3577 * GDB can now be built as a native debugger for debugging Windows x86
3578 (mingw32) Portable Executable (PE) programs.
3580 * Pending breakpoints no longer change their number when their address
3583 * GDB now supports breakpoints with multiple locations,
3584 including breakpoints on C++ constructors, inside C++ templates,
3585 and in inlined functions.
3587 * GDB's ability to debug optimized code has been improved. GDB more
3588 accurately identifies function bodies and lexical blocks that occupy
3589 more than one contiguous range of addresses.
3591 * Target descriptions can now describe registers for PowerPC.
3593 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3594 registers on PowerPC targets.
3596 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3597 targets even when the libthread_db library is not available.
3599 * The GDB remote stub, gdbserver, now supports the new file transfer
3600 commands (remote put, remote get, and remote delete).
3602 * The GDB remote stub, gdbserver, now supports run and attach in
3603 extended-remote mode.
3605 * hppa*64*-*-hpux11* target broken
3606 The debugger is unable to start a program and fails with the following
3607 error: "Error trying to get information about dynamic linker".
3608 The gdb-6.7 release is also affected.
3610 * GDB now supports the --enable-targets= configure option to allow
3611 building a single GDB executable that supports multiple remote
3612 target architectures.
3614 * GDB now supports debugging C and C++ programs which use the
3615 Decimal Floating Point extension. In addition, the PowerPC target
3616 now has a set of pseudo-registers to inspect decimal float values
3617 stored in two consecutive float registers.
3619 * The -break-insert MI command can optionally create pending
3622 * Improved support for debugging Ada
3623 Many improvements to the Ada language support have been made. These
3625 - Better support for Ada2005 interface types
3626 - Improved handling of arrays and slices in general
3627 - Better support for Taft-amendment types
3628 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3630 - Improved command completion in Ada
3633 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3638 set print frame-arguments (all|scalars|none)
3639 show print frame-arguments
3640 The value of this variable can be changed to control which argument
3641 values should be printed by the debugger when displaying a frame.
3646 Transfer files to and from a remote target, and delete remote files.
3653 Transfer files to and from a remote target, and delete remote files.
3655 * New remote packets
3662 Open, close, read, write, and delete files on the remote system.
3665 Attach to an existing process on the remote system, in extended-remote
3669 Run a new process on the remote system, in extended-remote mode.
3671 *** Changes in GDB 6.7
3673 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3674 bfd, libiberty and opcodes, as revealed by static analysis donated by
3675 Coverity, Inc. (http://scan.coverity.com).
3677 * When looking up multiply-defined global symbols, GDB will now prefer the
3678 symbol definition in the current shared library if it was built using the
3679 -Bsymbolic linker option.
3681 * When the Text User Interface (TUI) is not configured, GDB will now
3682 recognize the -tui command-line option and print a message that the TUI
3685 * The GDB remote stub, gdbserver, now has lower overhead for high
3686 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3688 * GDB for MIPS targets now autodetects whether a remote target provides
3689 32-bit or 64-bit register values.
3691 * Support for C++ member pointers has been improved.
3693 * GDB now understands XML target descriptions, which specify the
3694 target's overall architecture. GDB can read a description from
3695 a local file or over the remote serial protocol.
3697 * Vectors of single-byte data use a new integer type which is not
3698 automatically displayed as character or string data.
3700 * The /s format now works with the print command. It displays
3701 arrays of single-byte integers and pointers to single-byte integers
3704 * Target descriptions can now describe target-specific registers,
3705 for architectures which have implemented the support (currently
3706 only ARM, M68K, and MIPS).
3708 * GDB and the GDB remote stub, gdbserver, now support the XScale
3711 * The GDB remote stub, gdbserver, has been updated to support
3712 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3713 has been rewritten to use the standard GDB remote protocol.
3715 * GDB can now step into C++ functions which are called through thunks.
3717 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3719 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3720 layout. It also supports a TextSeg= and DataSeg= response when only
3721 segment base addresses (rather than offsets) are available.
3723 * The /i format now outputs any trailing branch delay slot instructions
3724 immediately following the last instruction within the count specified.
3726 * The GDB remote protocol "T" stop reply packet now supports a
3727 "library" response. Combined with the new "qXfer:libraries:read"
3728 packet, this response allows GDB to debug shared libraries on targets
3729 where the operating system manages the list of loaded libraries (e.g.
3730 Windows and SymbianOS).
3732 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3733 (DLLs) on Windows and Windows CE targets.
3735 * GDB now supports a faster verification that a .debug file matches its binary
3736 according to its build-id signature, if the signature is present.
3742 Enable or disable hardware flow control (RTS/CTS) on the serial port
3743 when debugging using remote targets.
3745 set mem inaccessible-by-default
3746 show mem inaccessible-by-default
3747 If the target supplies a memory map, for instance via the remote
3748 protocol's "qXfer:memory-map:read" packet, setting this variable
3749 prevents GDB from accessing memory outside the memory map. This
3750 is useful for targets with memory mapped registers or which react
3751 badly to accesses of unmapped address space.
3753 set breakpoint auto-hw
3754 show breakpoint auto-hw
3755 If the target supplies a memory map, for instance via the remote
3756 protocol's "qXfer:memory-map:read" packet, setting this variable
3757 lets GDB use hardware breakpoints automatically for memory regions
3758 where it can not use software breakpoints. This covers both the
3759 "break" command and internal breakpoints used for other commands
3760 including "next" and "finish".
3763 catch exception unhandled
3764 Stop the program execution when Ada exceptions are raised.
3767 Stop the program execution when an Ada assertion failed.
3771 Set an alternate system root for target files. This is a more
3772 general version of "set solib-absolute-prefix", which is now
3773 an alias to "set sysroot".
3776 Provide extended SPU facility status information. This set of
3777 commands is available only when debugging the Cell/B.E. SPU
3780 * New native configurations
3782 OpenBSD/sh sh*-*openbsd*
3785 unset tdesc filename
3787 Use the specified local file as an XML target description, and do
3788 not query the target for its built-in description.
3792 OpenBSD/sh sh*-*-openbsd*
3793 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3794 Toshiba Media Processor mep-elf
3796 * New remote packets
3799 Ignore the specified signals; pass them directly to the debugged program
3800 without stopping other threads or reporting them to GDB.
3802 qXfer:features:read:
3803 Read an XML target description from the target, which describes its
3808 Read or write contents of an spufs file on the target system. These
3809 packets are available only on the Cell/B.E. SPU architecture.
3811 qXfer:libraries:read:
3812 Report the loaded shared libraries. Combined with new "T" packet
3813 response, this packet allows GDB to debug shared libraries on
3814 targets where the operating system manages the list of loaded
3815 libraries (e.g. Windows and SymbianOS).
3819 Support for these obsolete configurations has been removed.
3827 i[34567]86-*-lynxos*
3828 i[34567]86-*-netware*
3829 i[34567]86-*-sco3.2v5*
3830 i[34567]86-*-sco3.2v4*
3832 i[34567]86-*-sysv4.2*
3835 i[34567]86-*-unixware2*
3836 i[34567]86-*-unixware*
3845 * Other removed features
3852 Various m68k-only ROM monitors.
3859 Various Renesas ROM monitors and debugging interfaces for SH and
3864 Support for a Macraigor serial interface to on-chip debugging.
3865 GDB does not directly support the newer parallel or USB
3870 A debug information format. The predecessor to DWARF 2 and
3871 DWARF 3, which are still supported.
3873 Support for the HP aCC compiler on HP-UX/PA-RISC
3875 SOM-encapsulated symbolic debugging information, automatic
3876 invocation of pxdb, and the aCC custom C++ ABI. This does not
3877 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
3878 with aCC can still be debugged on an assembly level.
3880 MIPS ".pdr" sections
3882 A MIPS-specific format used to describe stack frame layout
3883 in debugging information.
3887 GDB could work with an older version of Guile to debug
3888 the interpreter and Scheme programs running in it.
3890 set mips stack-arg-size
3891 set mips saved-gpreg-size
3893 Use "set mips abi" to control parameter passing for MIPS.
3895 *** Changes in GDB 6.6
3900 Cell Broadband Engine SPU spu-elf
3902 * GDB can now be configured as a cross-debugger targeting native Windows
3903 (mingw32) or Cygwin. It can communicate with a remote debugging stub
3904 running on a Windows system over TCP/IP to debug Windows programs.
3906 * The GDB remote stub, gdbserver, has been updated to support Windows and
3907 Cygwin debugging. Both single-threaded and multi-threaded programs are
3910 * The "set trust-readonly-sections" command works again. This command was
3911 broken in GDB 6.3, 6.4, and 6.5.
3913 * The "load" command now supports writing to flash memory, if the remote
3914 stub provides the required support.
3916 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
3917 longer requires symbolic debug information (e.g. DWARF-2).
3922 unset substitute-path
3923 show substitute-path
3924 Manage a list of substitution rules that GDB uses to rewrite the name
3925 of the directories where the sources are located. This can be useful
3926 for instance when the sources were moved to a different location
3927 between compilation and debugging.
3931 Print each CLI command as it is executed. Each command is prefixed with
3932 a number of `+' symbols representing the nesting depth.
3933 The source command now has a `-v' option to enable the same feature.
3937 The ARM Demon monitor support (RDP protocol, "target rdp").
3939 Kernel Object Display, an embedded debugging feature which only worked with
3940 an obsolete version of Cisco IOS.
3942 The 'set download-write-size' and 'show download-write-size' commands.
3944 * New remote packets
3947 Tell a stub about GDB client features, and request remote target features.
3948 The first feature implemented is PacketSize, which allows the target to
3949 specify the size of packets it can handle - to minimize the number of
3950 packets required and improve performance when connected to a remote
3954 Fetch an OS auxilliary vector from the remote stub. This packet is a
3955 more efficient replacement for qPart:auxv:read.
3957 qXfer:memory-map:read:
3958 Fetch a memory map from the remote stub, including information about
3959 RAM, ROM, and flash memory devices.
3964 Erase and program a flash memory device.
3966 * Removed remote packets
3969 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
3970 used it, and only gdbserver implemented it.
3972 *** Changes in GDB 6.5
3976 Renesas M32C/M16C m32c-elf
3978 Morpho Technologies ms1 ms1-elf
3982 init-if-undefined Initialize a convenience variable, but
3983 only if it doesn't already have a value.
3985 The following commands are presently only implemented for native GNU/Linux:
3987 checkpoint Save a snapshot of the program state.
3989 restart <n> Return the program state to a
3990 previously saved state.
3992 info checkpoints List currently saved checkpoints.
3994 delete-checkpoint <n> Delete a previously saved checkpoint.
3996 set|show detach-on-fork Tell gdb whether to detach from a newly
3997 forked process, or to keep debugging it.
3999 info forks List forks of the user program that
4000 are available to be debugged.
4002 fork <n> Switch to debugging one of several
4003 forks of the user program that are
4004 available to be debugged.
4006 delete-fork <n> Delete a fork from the list of forks
4007 that are available to be debugged (and
4008 kill the forked process).
4010 detach-fork <n> Delete a fork from the list of forks
4011 that are available to be debugged (and
4012 allow the process to continue).
4016 Morpho Technologies ms2 ms1-elf
4018 * Improved Windows host support
4020 GDB now builds as a cross debugger hosted on i686-mingw32, including
4021 native console support, and remote communications using either
4022 network sockets or serial ports.
4024 * Improved Modula-2 language support
4026 GDB can now print most types in the Modula-2 syntax. This includes:
4027 basic types, set types, record types, enumerated types, range types,
4028 pointer types and ARRAY types. Procedure var parameters are correctly
4029 printed and hexadecimal addresses and character constants are also
4030 written in the Modula-2 syntax. Best results can be obtained by using
4031 GNU Modula-2 together with the -gdwarf-2 command line option.
4035 The ARM rdi-share module.
4037 The Netware NLM debug server.
4039 *** Changes in GDB 6.4
4041 * New native configurations
4043 OpenBSD/arm arm*-*-openbsd*
4044 OpenBSD/mips64 mips64-*-openbsd*
4048 Morpho Technologies ms1 ms1-elf
4050 * New command line options
4052 --batch-silent As for --batch, but totally silent.
4053 --return-child-result The debugger will exist with the same value
4054 the child (debugged) program exited with.
4055 --eval-command COMMAND, -ex COMMAND
4056 Execute a single GDB CLI command. This may be
4057 specified multiple times and in conjunction
4058 with the --command (-x) option.
4060 * Deprecated commands removed
4062 The following commands, that were deprecated in 2000, have been
4066 set|show arm disassembly-flavor set|show arm disassembler
4067 othernames set arm disassembler
4068 set|show remotedebug set|show debug remote
4069 set|show archdebug set|show debug arch
4070 set|show eventdebug set|show debug event
4073 * New BSD user-level threads support
4075 It is now possible to debug programs using the user-level threads
4076 library on OpenBSD and FreeBSD. Currently supported (target)
4079 FreeBSD/amd64 x86_64-*-freebsd*
4080 FreeBSD/i386 i386-*-freebsd*
4081 OpenBSD/i386 i386-*-openbsd*
4083 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4084 are not yet supported.
4086 * New support for Matsushita MN10300 w/sim added
4087 (Work in progress). mn10300-elf.
4089 * REMOVED configurations and files
4091 VxWorks and the XDR protocol *-*-vxworks
4092 Motorola MCORE mcore-*-*
4093 National Semiconductor NS32000 ns32k-*-*
4095 * New "set print array-indexes" command
4097 After turning this setting "on", GDB prints the index of each element
4098 when displaying arrays. The default is "off" to preserve the previous
4101 * VAX floating point support
4103 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4105 * User-defined command support
4107 In addition to using $arg0..$arg9 for argument passing, it is now possible
4108 to use $argc to determine now many arguments have been passed. See the
4109 section on user-defined commands in the user manual for more information.
4111 *** Changes in GDB 6.3:
4113 * New command line option
4115 GDB now accepts -l followed by a number to set the timeout for remote
4118 * GDB works with GCC -feliminate-dwarf2-dups
4120 GDB now supports a more compact representation of DWARF-2 debug
4121 information using DW_FORM_ref_addr references. These are produced
4122 by GCC with the option -feliminate-dwarf2-dups and also by some
4123 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4124 to use -feliminate-dwarf2-dups.
4126 * Internationalization
4128 When supported by the host system, GDB will be built with
4129 internationalization (libintl). The task of marking up the sources is
4130 continued, we're looking forward to our first translation.
4134 Initial support for debugging programs compiled with the GNAT
4135 implementation of the Ada programming language has been integrated
4136 into GDB. In this release, support is limited to expression evaluation.
4138 * New native configurations
4140 GNU/Linux/m32r m32r-*-linux-gnu
4144 GDB's remote protocol now includes support for the 'p' packet. This
4145 packet is used to fetch individual registers from a remote inferior.
4147 * END-OF-LIFE registers[] compatibility module
4149 GDB's internal register infrastructure has been completely rewritten.
4150 The new infrastructure making possible the implementation of key new
4151 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4154 GDB 6.3 will be the last release to include the the registers[]
4155 compatibility module that allowed out-of-date configurations to
4156 continue to work. This change directly impacts the following
4166 powerpc bdm protocol
4168 Unless there is activity to revive these configurations, they will be
4169 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4171 * OBSOLETE configurations and files
4173 Configurations that have been declared obsolete in this release have
4174 been commented out. Unless there is activity to revive these
4175 configurations, the next release of GDB will have their sources
4176 permanently REMOVED.
4185 *** Changes in GDB 6.2.1:
4187 * MIPS `break main; run' gave an heuristic-fence-post warning
4189 When attempting to run even a simple program, a warning about
4190 heuristic-fence-post being hit would be reported. This problem has
4193 * MIPS IRIX 'long double' crashed GDB
4195 When examining a long double variable, GDB would get a segmentation
4196 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4197 IRIX long double values).
4201 A bug in the VAX stack code was causing problems with the "next"
4202 command. This problem has been fixed.
4204 *** Changes in GDB 6.2:
4206 * Fix for ``many threads''
4208 On GNU/Linux systems that use the NPTL threads library, a program
4209 rapidly creating and deleting threads would confuse GDB leading to the
4212 ptrace: No such process.
4213 thread_db_get_info: cannot get thread info: generic error
4215 This problem has been fixed.
4217 * "-async" and "-noasync" options removed.
4219 Support for the broken "-noasync" option has been removed (it caused
4222 * New ``start'' command.
4224 This command runs the program until the begining of the main procedure.
4226 * New BSD Kernel Data Access Library (libkvm) interface
4228 Using ``target kvm'' it is now possible to debug kernel core dumps and
4229 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4230 platforms. Currently supported (native-only) configurations are:
4232 FreeBSD/amd64 x86_64-*-freebsd*
4233 FreeBSD/i386 i?86-*-freebsd*
4234 NetBSD/i386 i?86-*-netbsd*
4235 NetBSD/m68k m68*-*-netbsd*
4236 NetBSD/sparc sparc-*-netbsd*
4237 OpenBSD/amd64 x86_64-*-openbsd*
4238 OpenBSD/i386 i?86-*-openbsd*
4239 OpenBSD/m68k m68*-openbsd*
4240 OpenBSD/sparc sparc-*-openbsd*
4242 * Signal trampoline code overhauled
4244 Many generic problems with GDB's signal handling code have been fixed.
4245 These include: backtraces through non-contiguous stacks; recognition
4246 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4247 call; backtrace through a signal trampoline; step into and out of
4248 signal handlers; and single-stepping in the signal trampoline.
4250 Please note that kernel bugs are a limiting factor here. These
4251 features have been shown to work on an s390 GNU/Linux system that
4252 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4254 * Cygwin support for DWARF 2 added.
4256 * New native configurations
4258 GNU/Linux/hppa hppa*-*-linux*
4259 OpenBSD/hppa hppa*-*-openbsd*
4260 OpenBSD/m68k m68*-*-openbsd*
4261 OpenBSD/m88k m88*-*-openbsd*
4262 OpenBSD/powerpc powerpc-*-openbsd*
4263 NetBSD/vax vax-*-netbsd*
4264 OpenBSD/vax vax-*-openbsd*
4266 * END-OF-LIFE frame compatibility module
4268 GDB's internal frame infrastructure has been completely rewritten.
4269 The new infrastructure making it possible to support key new features
4270 including DWARF 2 Call Frame Information. To aid in the task of
4271 migrating old configurations to this new infrastructure, a
4272 compatibility module, that allowed old configurations to continue to
4273 work, was also included.
4275 GDB 6.2 will be the last release to include this frame compatibility
4276 module. This change directly impacts the following configurations:
4286 Unless there is activity to revive these configurations, they will be
4287 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4289 * REMOVED configurations and files
4291 Sun 3, running SunOS 3 m68*-*-sunos3*
4292 Sun 3, running SunOS 4 m68*-*-sunos4*
4293 Sun 2, running SunOS 3 m68000-*-sunos3*
4294 Sun 2, running SunOS 4 m68000-*-sunos4*
4295 Motorola 680x0 running LynxOS m68*-*-lynxos*
4296 AT&T 3b1/Unix pc m68*-att-*
4297 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4298 decstation mips-dec-* mips-little-*
4299 riscos mips-*-riscos* mips-*-sysv*
4300 sonymips mips-sony-*
4301 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4303 *** Changes in GDB 6.1.1:
4305 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4307 The TUI (Text-mode User Interface) is now built as part of a default
4308 GDB configuration. It is enabled by either selecting the TUI with the
4309 command line option "-i=tui" or by running the separate "gdbtui"
4310 program. For more information on the TUI, see the manual "Debugging
4313 * Pending breakpoint support (also included in GDB 6.1)
4315 Support has been added to allow you to specify breakpoints in shared
4316 libraries that have not yet been loaded. If a breakpoint location
4317 cannot be found, and the "breakpoint pending" option is set to auto,
4318 GDB queries you if you wish to make the breakpoint pending on a future
4319 shared-library load. If and when GDB resolves the breakpoint symbol,
4320 the pending breakpoint is removed as one or more regular breakpoints
4323 Pending breakpoints are very useful for GCJ Java debugging.
4325 * Fixed ISO-C build problems
4327 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4328 non ISO-C code that stopped them being built using a more strict ISO-C
4329 compiler (e.g., IBM's C compiler).
4331 * Fixed build problem on IRIX 5
4333 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4334 wasn't able to compile compile on an IRIX 5 system.
4336 * Added execute permission to gdb/gdbserver/configure
4338 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4339 permission. This bug would cause configure to fail on a number of
4340 systems (Solaris, IRIX). Ref: server/519.
4342 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4344 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4345 has been updated to use constant array sizes.
4347 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4349 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4350 its generated DWARF Call Frame Info. This encoding was causing GDB to
4351 panic, that panic has been fixed. Ref: gdb/1628.
4353 * Fixed a problem when examining parameters in shared library code.
4355 When examining parameters in optimized shared library code generated
4356 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4357 not available''. GDB now correctly displays the variable's value.
4359 *** Changes in GDB 6.1:
4361 * Removed --with-mmalloc
4363 Support for the mmalloc memory manager has been removed, as it
4364 conflicted with the internal gdb byte cache.
4366 * Changes in AMD64 configurations
4368 The AMD64 target now includes the %cs and %ss registers. As a result
4369 the AMD64 remote protocol has changed; this affects the floating-point
4370 and SSE registers. If you rely on those registers for your debugging,
4371 you should upgrade gdbserver on the remote side.
4373 * Revised SPARC target
4375 The SPARC target has been completely revised, incorporating the
4376 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4377 support for LynxOS and SunOS 4 has been dropped. Calling functions
4378 from within GDB on operating systems with a non-executable stack
4379 (Solaris, OpenBSD) now works.
4383 GDB has a new C++ demangler which does a better job on the mangled
4384 names generated by current versions of g++. It also runs faster, so
4385 with this and other changes gdb should now start faster on large C++
4388 * DWARF 2 Location Expressions
4390 GDB support for location expressions has been extended to support function
4391 arguments and frame bases. Older versions of GDB could crash when they
4394 * C++ nested types and namespaces
4396 GDB's support for nested types and namespaces in C++ has been
4397 improved, especially if you use the DWARF 2 debugging format. (This
4398 is the default for recent versions of GCC on most platforms.)
4399 Specifically, if you have a class "Inner" defined within a class or
4400 namespace "Outer", then GDB realizes that the class's name is
4401 "Outer::Inner", not simply "Inner". This should greatly reduce the
4402 frequency of complaints about not finding RTTI symbols. In addition,
4403 if you are stopped at inside of a function defined within a namespace,
4404 GDB modifies its name lookup accordingly.
4406 * New native configurations
4408 NetBSD/amd64 x86_64-*-netbsd*
4409 OpenBSD/amd64 x86_64-*-openbsd*
4410 OpenBSD/alpha alpha*-*-openbsd*
4411 OpenBSD/sparc sparc-*-openbsd*
4412 OpenBSD/sparc64 sparc64-*-openbsd*
4414 * New debugging protocols
4416 M32R with SDI protocol m32r-*-elf*
4418 * "set prompt-escape-char" command deleted.
4420 The command "set prompt-escape-char" has been deleted. This command,
4421 and its very obscure effet on GDB's prompt, was never documented,
4422 tested, nor mentioned in the NEWS file.
4424 * OBSOLETE configurations and files
4426 Configurations that have been declared obsolete in this release have
4427 been commented out. Unless there is activity to revive these
4428 configurations, the next release of GDB will have their sources
4429 permanently REMOVED.
4431 Sun 3, running SunOS 3 m68*-*-sunos3*
4432 Sun 3, running SunOS 4 m68*-*-sunos4*
4433 Sun 2, running SunOS 3 m68000-*-sunos3*
4434 Sun 2, running SunOS 4 m68000-*-sunos4*
4435 Motorola 680x0 running LynxOS m68*-*-lynxos*
4436 AT&T 3b1/Unix pc m68*-att-*
4437 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4438 decstation mips-dec-* mips-little-*
4439 riscos mips-*-riscos* mips-*-sysv*
4440 sonymips mips-sony-*
4441 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4443 * REMOVED configurations and files
4445 SGI Irix-4.x mips-sgi-irix4 or iris4
4446 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4447 Z8000 simulator z8k-zilog-none or z8ksim
4448 Matsushita MN10200 w/simulator mn10200-*-*
4449 H8/500 simulator h8500-hitachi-hms or h8500hms
4450 HP/PA running BSD hppa*-*-bsd*
4451 HP/PA running OSF/1 hppa*-*-osf*
4452 HP/PA Pro target hppa*-*-pro*
4453 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4454 386BSD i[3456]86-*-bsd*
4455 Sequent family i[3456]86-sequent-sysv4*
4456 i[3456]86-sequent-sysv*
4457 i[3456]86-sequent-bsd*
4458 SPARC running LynxOS sparc-*-lynxos*
4459 SPARC running SunOS 4 sparc-*-sunos4*
4460 Tsqware Sparclet sparclet-*-*
4461 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4463 *** Changes in GDB 6.0:
4467 Support for debugging the Objective-C programming language has been
4468 integrated into GDB.
4470 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4472 DWARF 2's Call Frame Information makes available compiler generated
4473 information that more exactly describes the program's run-time stack.
4474 By using this information, GDB is able to provide more robust stack
4477 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4478 have been updated to use a new backtrace mechanism which includes
4479 DWARF 2 CFI support.
4483 GDB's remote protocol has been extended to include support for hosted
4484 file I/O (where the remote target uses GDB's file system). See GDB's
4485 remote protocol documentation for details.
4487 * All targets using the new architecture framework.
4489 All of GDB's targets have been updated to use the new internal
4490 architecture framework. The way is now open for future GDB releases
4491 to include cross-architecture native debugging support (i386 on amd64,
4494 * GNU/Linux's Thread Local Storage (TLS)
4496 GDB now includes support for for the GNU/Linux implementation of
4497 per-thread variables.
4499 * GNU/Linux's Native POSIX Thread Library (NPTL)
4501 GDB's thread code has been updated to work with either the new
4502 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4504 * Separate debug info.
4506 GDB, in conjunction with BINUTILS, now supports a mechanism for
4507 automatically loading debug information from a separate file. Instead
4508 of shipping full debug and non-debug versions of system libraries,
4509 system integrators can now instead ship just the stripped libraries
4510 and optional debug files.
4512 * DWARF 2 Location Expressions
4514 DWARF 2 Location Expressions allow the compiler to more completely
4515 describe the location of variables (even in optimized code) to the
4518 GDB now includes preliminary support for location expressions (support
4519 for DW_OP_piece is still missing).
4523 A number of long standing bugs that caused GDB to die while starting a
4524 Java application have been fixed. GDB's Java support is now
4525 considered "useable".
4527 * GNU/Linux support for fork, vfork, and exec.
4529 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4530 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4533 * GDB supports logging output to a file
4535 There are two new commands, "set logging" and "show logging", which can be
4536 used to capture GDB's output to a file.
4538 * The meaning of "detach" has changed for gdbserver
4540 The "detach" command will now resume the application, as documented. To
4541 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4544 * d10v, m68hc11 `regs' command deprecated
4546 The `info registers' command has been updated so that it displays the
4547 registers using a format identical to the old `regs' command.
4551 A new command, "maint set profile on/off", has been added. This command can
4552 be used to enable or disable profiling while running GDB, to profile a
4553 session or a set of commands. In addition there is a new configure switch,
4554 "--enable-profiling", which will cause GDB to be compiled with profiling
4555 data, for more informative profiling results.
4557 * Default MI syntax changed to "mi2".
4559 The default MI (machine interface) syntax, enabled by the command line
4560 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4561 "mi1", can be enabled by specifying the option "-i=mi1".
4563 Support for the original "mi0" syntax (included in GDB 5.0) has been
4566 Fix for gdb/192: removed extraneous space when displaying frame level.
4567 Fix for gdb/672: update changelist is now output in mi list format.
4568 Fix for gdb/702: a -var-assign that updates the value now shows up
4569 in a subsequent -var-update.
4571 * New native configurations.
4573 FreeBSD/amd64 x86_64-*-freebsd*
4575 * Multi-arched targets.
4577 HP/PA HPUX11 hppa*-*-hpux*
4578 Renesas M32R/D w/simulator m32r-*-elf*
4580 * OBSOLETE configurations and files
4582 Configurations that have been declared obsolete in this release have
4583 been commented out. Unless there is activity to revive these
4584 configurations, the next release of GDB will have their sources
4585 permanently REMOVED.
4587 Z8000 simulator z8k-zilog-none or z8ksim
4588 Matsushita MN10200 w/simulator mn10200-*-*
4589 H8/500 simulator h8500-hitachi-hms or h8500hms
4590 HP/PA running BSD hppa*-*-bsd*
4591 HP/PA running OSF/1 hppa*-*-osf*
4592 HP/PA Pro target hppa*-*-pro*
4593 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4594 Sequent family i[3456]86-sequent-sysv4*
4595 i[3456]86-sequent-sysv*
4596 i[3456]86-sequent-bsd*
4597 Tsqware Sparclet sparclet-*-*
4598 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4600 * REMOVED configurations and files
4603 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4604 IBM AIX PS/2 i[3456]86-*-aix
4605 i386 running Mach 3.0 i[3456]86-*-mach3*
4606 i386 running Mach i[3456]86-*-mach*
4607 i386 running OSF/1 i[3456]86-*osf1mk*
4608 HP/Apollo 68k Family m68*-apollo*-sysv*,
4610 m68*-hp-bsd*, m68*-hp-hpux*
4611 Argonaut Risc Chip (ARC) arc-*-*
4612 Mitsubishi D30V d30v-*-*
4613 Fujitsu FR30 fr30-*-elf*
4614 OS/9000 i[34]86-*-os9k
4615 I960 with MON960 i960-*-coff
4617 * MIPS $fp behavior changed
4619 The convenience variable $fp, for the MIPS, now consistently returns
4620 the address of the current frame's base. Previously, depending on the
4621 context, $fp could refer to either $sp or the current frame's base
4622 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4623 The GNU Source-Level Debugger''.
4625 *** Changes in GDB 5.3:
4627 * GNU/Linux shared library multi-threaded performance improved.
4629 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4630 `/proc', in preference to `ptrace' for memory reads. This may result
4631 in an improvement in the start-up time of multi-threaded, shared
4632 library applications when run under GDB. One GDB user writes: ``loads
4633 shared libs like mad''.
4635 * ``gdbserver'' now supports multi-threaded applications on some targets
4637 Support for debugging multi-threaded applications which use
4638 the GNU/Linux LinuxThreads package has been added for
4639 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4640 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4642 * GDB now supports C/C++ preprocessor macros.
4644 GDB now expands preprocessor macro invocations in C/C++ expressions,
4645 and provides various commands for showing macro definitions and how
4648 The new command `macro expand EXPRESSION' expands any macro
4649 invocations in expression, and shows the result.
4651 The new command `show macro MACRO-NAME' shows the definition of the
4652 macro named MACRO-NAME, and where it was defined.
4654 Most compilers don't include information about macros in the debugging
4655 information by default. In GCC 3.1, for example, you need to compile
4656 your program with the options `-gdwarf-2 -g3'. If the macro
4657 information is present in the executable, GDB will read it.
4659 * Multi-arched targets.
4661 DEC Alpha (partial) alpha*-*-*
4662 DEC VAX (partial) vax-*-*
4664 National Semiconductor NS32000 (partial) ns32k-*-*
4665 Motorola 68000 (partial) m68k-*-*
4666 Motorola MCORE mcore-*-*
4670 Fujitsu FRV architecture added by Red Hat frv*-*-*
4673 * New native configurations
4675 Alpha NetBSD alpha*-*-netbsd*
4676 SH NetBSD sh*-*-netbsdelf*
4677 MIPS NetBSD mips*-*-netbsd*
4678 UltraSPARC NetBSD sparc64-*-netbsd*
4680 * OBSOLETE configurations and files
4682 Configurations that have been declared obsolete in this release have
4683 been commented out. Unless there is activity to revive these
4684 configurations, the next release of GDB will have their sources
4685 permanently REMOVED.
4687 Mitsubishi D30V d30v-*-*
4688 OS/9000 i[34]86-*-os9k
4689 IBM AIX PS/2 i[3456]86-*-aix
4690 Fujitsu FR30 fr30-*-elf*
4691 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4692 Argonaut Risc Chip (ARC) arc-*-*
4693 i386 running Mach 3.0 i[3456]86-*-mach3*
4694 i386 running Mach i[3456]86-*-mach*
4695 i386 running OSF/1 i[3456]86-*osf1mk*
4696 HP/Apollo 68k Family m68*-apollo*-sysv*,
4698 m68*-hp-bsd*, m68*-hp-hpux*
4699 I960 with MON960 i960-*-coff
4701 * OBSOLETE languages
4703 CHILL, a Pascal like language used by telecommunications companies.
4705 * REMOVED configurations and files
4707 AMD 29k family via UDI a29k-amd-udi, udi29k
4708 A29K VxWorks a29k-*-vxworks
4709 AMD 29000 embedded, using EBMON a29k-none-none
4710 AMD 29000 embedded with COFF a29k-none-coff
4711 AMD 29000 embedded with a.out a29k-none-aout
4713 testsuite/gdb.hp/gdb.threads-hp/ directory
4715 * New command "set max-user-call-depth <nnn>"
4717 This command allows the user to limit the call depth of user-defined
4718 commands. The default is 1024.
4720 * Changes in FreeBSD/i386 native debugging.
4722 Support for the "generate-core-file" has been added.
4724 * New commands "dump", "append", and "restore".
4726 These commands allow data to be copied from target memory
4727 to a bfd-format or binary file (dump and append), and back
4728 from a file into memory (restore).
4730 * Improved "next/step" support on multi-processor Alpha Tru64.
4732 The previous single-step mechanism could cause unpredictable problems,
4733 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4734 of a software single-step mechanism prevents this.
4736 *** Changes in GDB 5.2.1:
4744 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4745 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4746 Fix, by Joel Brobecker imported from mainline.
4748 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4749 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4750 Fix, by Fred Fish, imported from mainline.
4752 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4753 Surprisingly enough, it works now.
4754 By Michal Ludvig, imported from mainline.
4756 i386 hardware watchpoint support:
4757 avoid misses on second run for some targets.
4758 By Pierre Muller, imported from mainline.
4760 *** Changes in GDB 5.2:
4762 * New command "set trust-readonly-sections on[off]".
4764 This command is a hint that tells gdb that read-only sections
4765 really are read-only (ie. that their contents will not change).
4766 In this mode, gdb will go to the object file rather than the
4767 target to read memory from read-only sections (such as ".text").
4768 This can be a significant performance improvement on some
4769 (notably embedded) targets.
4771 * New command "generate-core-file" (or "gcore").
4773 This new gdb command allows the user to drop a core file of the child
4774 process state at any time. So far it's been implemented only for
4775 GNU/Linux and Solaris, but should be relatively easily ported to other
4776 hosts. Argument is core file name (defaults to core.<pid>).
4778 * New command line option
4780 GDB now accepts --pid or -p followed by a process id.
4782 * Change in command line behavior -- corefiles vs. process ids.
4784 There is a subtle behavior in the way in which GDB handles
4785 command line arguments. The first non-flag argument is always
4786 a program to debug, but the second non-flag argument may either
4787 be a corefile or a process id. Previously, GDB would attempt to
4788 open the second argument as a corefile, and if that failed, would
4789 issue a superfluous error message and then attempt to attach it as
4790 a process. Now, if the second argument begins with a non-digit,
4791 it will be treated as a corefile. If it begins with a digit,
4792 GDB will attempt to attach it as a process, and if no such process
4793 is found, will then attempt to open it as a corefile.
4795 * Changes in ARM configurations.
4797 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4798 configuration is fully multi-arch.
4800 * New native configurations
4802 ARM NetBSD arm*-*-netbsd*
4803 x86 OpenBSD i[3456]86-*-openbsd*
4804 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4805 Sparc64 running FreeBSD sparc64-*-freebsd*
4809 Sanyo XStormy16 xstormy16-elf
4811 * OBSOLETE configurations and files
4813 Configurations that have been declared obsolete in this release have
4814 been commented out. Unless there is activity to revive these
4815 configurations, the next release of GDB will have their sources
4816 permanently REMOVED.
4818 AMD 29k family via UDI a29k-amd-udi, udi29k
4819 A29K VxWorks a29k-*-vxworks
4820 AMD 29000 embedded, using EBMON a29k-none-none
4821 AMD 29000 embedded with COFF a29k-none-coff
4822 AMD 29000 embedded with a.out a29k-none-aout
4824 testsuite/gdb.hp/gdb.threads-hp/ directory
4826 * REMOVED configurations and files
4828 TI TMS320C80 tic80-*-*
4830 PowerPC Solaris powerpcle-*-solaris*
4831 PowerPC Windows NT powerpcle-*-cygwin32
4832 PowerPC Netware powerpc-*-netware*
4833 Harris/CXUX m88k m88*-harris-cxux*
4834 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4835 ns32k-utek-sysv* ns32k-utek-*
4836 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4837 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4838 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4839 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4840 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4842 * Changes to command line processing
4844 The new `--args' feature can be used to specify command-line arguments
4845 for the inferior from gdb's command line.
4847 * Changes to key bindings
4849 There is a new `operate-and-get-next' function bound to `C-o'.
4851 *** Changes in GDB 5.1.1
4853 Fix compile problem on DJGPP.
4855 Fix a problem with floating-point registers on the i386 being
4858 Fix to stop GDB crashing on .debug_str debug info.
4860 Numerous documentation fixes.
4862 Numerous testsuite fixes.
4864 *** Changes in GDB 5.1:
4866 * New native configurations
4868 Alpha FreeBSD alpha*-*-freebsd*
4869 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
4870 MIPS GNU/Linux mips*-*-linux*
4871 MIPS SGI Irix 6.x mips*-sgi-irix6*
4872 ia64 AIX ia64-*-aix*
4873 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
4877 Motorola 68HC11 and 68HC12 m68hc11-elf
4879 UltraSparc running GNU/Linux sparc64-*-linux*
4881 * OBSOLETE configurations and files
4883 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
4884 Harris/CXUX m88k m88*-harris-cxux*
4885 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4886 ns32k-utek-sysv* ns32k-utek-*
4887 TI TMS320C80 tic80-*-*
4889 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4890 PowerPC Solaris powerpcle-*-solaris*
4891 PowerPC Windows NT powerpcle-*-cygwin32
4892 PowerPC Netware powerpc-*-netware*
4893 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4894 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4895 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4896 Apple Macintosh (MPW) host N/A
4898 stuff.c (Program to stuff files into a specially prepared space in kdb)
4899 kdb-start.c (Main loop for the standalone kernel debugger)
4901 Configurations that have been declared obsolete in this release have
4902 been commented out. Unless there is activity to revive these
4903 configurations, the next release of GDB will have their sources
4904 permanently REMOVED.
4906 * REMOVED configurations and files
4908 Altos 3068 m68*-altos-*
4909 Convex c1-*-*, c2-*-*
4911 ARM RISCix arm-*-* (as host)
4915 * GDB has been converted to ISO C.
4917 GDB's source code has been converted to ISO C. In particular, the
4918 sources are fully protoized, and rely on standard headers being
4923 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
4925 * The MI enabled by default.
4927 The new machine oriented interface (MI) introduced in GDB 5.0 has been
4928 revised and enabled by default. Packages which use GDB as a debugging
4929 engine behind a UI or another front end are encouraged to switch to
4930 using the GDB/MI interface, instead of the old annotations interface
4931 which is now deprecated.
4933 * Support for debugging Pascal programs.
4935 GDB now includes support for debugging Pascal programs. The following
4936 main features are supported:
4938 - Pascal-specific data types such as sets;
4940 - automatic recognition of Pascal sources based on file-name
4943 - Pascal-style display of data types, variables, and functions;
4945 - a Pascal expression parser.
4947 However, some important features are not yet supported.
4949 - Pascal string operations are not supported at all;
4951 - there are some problems with boolean types;
4953 - Pascal type hexadecimal constants are not supported
4954 because they conflict with the internal variables format;
4956 - support for Pascal objects and classes is not full yet;
4958 - unlike Pascal, GDB is case-sensitive for symbol names.
4960 * Changes in completion.
4962 Commands such as `shell', `run' and `set args', which pass arguments
4963 to inferior programs, now complete on file names, similar to what
4964 users expect at the shell prompt.
4966 Commands which accept locations, such as `disassemble', `print',
4967 `breakpoint', `until', etc. now complete on filenames as well as
4968 program symbols. Thus, if you type "break foob TAB", and the source
4969 files linked into the programs include `foobar.c', that file name will
4970 be one of the candidates for completion. However, file names are not
4971 considered for completion after you typed a colon that delimits a file
4972 name from a name of a function in that file, as in "break foo.c:bar".
4974 `set demangle-style' completes on available demangling styles.
4976 * New platform-independent commands:
4978 It is now possible to define a post-hook for a command as well as a
4979 hook that runs before the command. For more details, see the
4980 documentation of `hookpost' in the GDB manual.
4982 * Changes in GNU/Linux native debugging.
4984 Support for debugging multi-threaded programs has been completely
4985 revised for all platforms except m68k and sparc. You can now debug as
4986 many threads as your system allows you to have.
4988 Attach/detach is supported for multi-threaded programs.
4990 Support for SSE registers was added for x86. This doesn't work for
4991 multi-threaded programs though.
4993 * Changes in MIPS configurations.
4995 Multi-arch support is enabled for all MIPS configurations.
4997 GDB can now be built as native debugger on SGI Irix 6.x systems for
4998 debugging n32 executables. (Debugging 64-bit executables is not yet
5001 * Unified support for hardware watchpoints in all x86 configurations.
5003 Most (if not all) native x86 configurations support hardware-assisted
5004 breakpoints and watchpoints in a unified manner. This support
5005 implements debug register sharing between watchpoints, which allows to
5006 put a virtually infinite number of watchpoints on the same address,
5007 and also supports watching regions up to 16 bytes with several debug
5010 The new maintenance command `maintenance show-debug-regs' toggles
5011 debugging print-outs in functions that insert, remove, and test
5012 watchpoints and hardware breakpoints.
5014 * Changes in the DJGPP native configuration.
5016 New command ``info dos sysinfo'' displays assorted information about
5017 the CPU, OS, memory, and DPMI server.
5019 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5020 display information about segment descriptors stored in GDT, LDT, and
5023 New commands ``info dos pde'' and ``info dos pte'' display entries
5024 from Page Directory and Page Tables (for now works with CWSDPMI only).
5025 New command ``info dos address-pte'' displays the Page Table entry for
5026 a given linear address.
5028 GDB can now pass command lines longer than 126 characters to the
5029 program being debugged (requires an update to the libdbg.a library
5030 which is part of the DJGPP development kit).
5032 DWARF2 debug info is now supported.
5034 It is now possible to `step' and `next' through calls to `longjmp'.
5036 * Changes in documentation.
5038 All GDB documentation was converted to GFDL, the GNU Free
5039 Documentation License.
5041 Tracepoints-related commands are now fully documented in the GDB
5044 TUI, the Text-mode User Interface, is now documented in the manual.
5046 Tracepoints-related commands are now fully documented in the GDB
5049 The "GDB Internals" manual now has an index. It also includes
5050 documentation of `ui_out' functions, GDB coding standards, x86
5051 hardware watchpoints, and memory region attributes.
5053 * GDB's version number moved to ``version.in''
5055 The Makefile variable VERSION has been replaced by the file
5056 ``version.in''. People creating GDB distributions should update the
5057 contents of this file.
5061 GUD support is now a standard part of the EMACS distribution.
5063 *** Changes in GDB 5.0:
5065 * Improved support for debugging FP programs on x86 targets
5067 Unified and much-improved support for debugging floating-point
5068 programs on all x86 targets. In particular, ``info float'' now
5069 displays the FP registers in the same format on all x86 targets, with
5070 greater level of detail.
5072 * Improvements and bugfixes in hardware-assisted watchpoints
5074 It is now possible to watch array elements, struct members, and
5075 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5076 on x86 targets no longer erroneously trigger when the address is
5079 * Improvements in the native DJGPP version of GDB
5081 The distribution now includes all the scripts and auxiliary files
5082 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5083 machines ``out of the box''.
5085 The DJGPP version can now debug programs that use signals. It is
5086 possible to catch signals that happened in the debuggee, deliver
5087 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5088 would kill the program being debugged.) Programs that hook hardware
5089 interrupts (keyboard, timer, etc.) can also be debugged.
5091 It is now possible to debug DJGPP programs that redirect their
5092 standard handles or switch them to raw (as opposed to cooked) mode, or
5093 even close them. The command ``run < foo > bar'' works as expected,
5094 and ``info terminal'' reports useful information about the debuggee's
5095 terminal, including raw/cooked mode, redirection, etc.
5097 The DJGPP version now uses termios functions for console I/O, which
5098 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5101 DOS-style file names with drive letters are now fully supported by
5104 It is now possible to debug DJGPP programs that switch their working
5105 directory. It is also possible to rerun the debuggee any number of
5106 times without restarting GDB; thus, you can use the same setup,
5107 breakpoints, etc. for many debugging sessions.
5109 * New native configurations
5111 ARM GNU/Linux arm*-*-linux*
5112 PowerPC GNU/Linux powerpc-*-linux*
5116 Motorola MCore mcore-*-*
5117 x86 VxWorks i[3456]86-*-vxworks*
5118 PowerPC VxWorks powerpc-*-vxworks*
5119 TI TMS320C80 tic80-*-*
5121 * OBSOLETE configurations
5123 Altos 3068 m68*-altos-*
5124 Convex c1-*-*, c2-*-*
5126 ARM RISCix arm-*-* (as host)
5129 Configurations that have been declared obsolete will be commented out,
5130 but the code will be left in place. If there is no activity to revive
5131 these configurations before the next release of GDB, the sources will
5132 be permanently REMOVED.
5134 * Gould support removed
5136 Support for the Gould PowerNode and NP1 has been removed.
5138 * New features for SVR4
5140 On SVR4 native platforms (such as Solaris), if you attach to a process
5141 without first loading a symbol file, GDB will now attempt to locate and
5142 load symbols from the running process's executable file.
5144 * Many C++ enhancements
5146 C++ support has been greatly improved. Overload resolution now works properly
5147 in almost all cases. RTTI support is on the way.
5149 * Remote targets can connect to a sub-program
5151 A popen(3) style serial-device has been added. This device starts a
5152 sub-process (such as a stand-alone simulator) and then communicates
5153 with that. The sub-program to run is specified using the syntax
5154 ``|<program> <args>'' vis:
5156 (gdb) set remotedebug 1
5157 (gdb) target extended-remote |mn10300-elf-sim program-args
5159 * MIPS 64 remote protocol
5161 A long standing bug in the mips64 remote protocol where by GDB
5162 expected certain 32 bit registers (ex SR) to be transfered as 32
5163 instead of 64 bits has been fixed.
5165 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5166 added to provide backward compatibility with older versions of GDB.
5168 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5170 The command ``set remotebinarydownload'' command has been replaced by
5171 ``set remote X-packet''. Other commands in ``set remote'' family
5172 include ``set remote P-packet''.
5174 * Breakpoint commands accept ranges.
5176 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5177 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5178 ``tracepoint passcount'' also accepts a range of tracepoints.
5180 * ``apropos'' command added.
5182 The ``apropos'' command searches through command names and
5183 documentation strings, printing out matches, making it much easier to
5184 try to find a command that does what you are looking for.
5188 A new machine oriented interface (MI) has been added to GDB. This
5189 interface is designed for debug environments running GDB as a separate
5190 process. This is part of the long term libGDB project. See the
5191 "GDB/MI" chapter of the GDB manual for further information. It can be
5192 enabled by configuring with:
5194 .../configure --enable-gdbmi
5196 *** Changes in GDB-4.18:
5198 * New native configurations
5200 HP-UX 10.20 hppa*-*-hpux10.20
5201 HP-UX 11.x hppa*-*-hpux11.0*
5202 M68K GNU/Linux m68*-*-linux*
5206 Fujitsu FR30 fr30-*-elf*
5207 Intel StrongARM strongarm-*-*
5208 Mitsubishi D30V d30v-*-*
5210 * OBSOLETE configurations
5212 Gould PowerNode, NP1 np1-*-*, pn-*-*
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.
5221 As a compatibility experiment, GDB's source files buildsym.h and
5222 buildsym.c have been converted to pure standard C, no longer
5223 containing any K&R compatibility code. We believe that all systems in
5224 use today either come with a standard C compiler, or have a GCC port
5225 available. If this is not true, please report the affected
5226 configuration to bug-gdb@gnu.org immediately. See the README file for
5227 information about getting a standard C compiler if you don't have one
5232 GDB now uses readline 2.2.
5234 * set extension-language
5236 You can now control the mapping between filename extensions and source
5237 languages by using the `set extension-language' command. For instance,
5238 you can ask GDB to treat .c files as C++ by saying
5239 set extension-language .c c++
5240 The command `info extensions' lists all of the recognized extensions
5241 and their associated languages.
5243 * Setting processor type for PowerPC and RS/6000
5245 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5246 you can use the `set processor' command to specify what variant of the
5247 PowerPC family you are debugging. The command
5251 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5252 following PowerPC and RS6000 variants:
5254 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5255 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5257 403GC IBM PowerPC 403GC
5258 505 Motorola PowerPC 505
5259 860 Motorola PowerPC 860 or 850
5260 601 Motorola PowerPC 601
5261 602 Motorola PowerPC 602
5262 603 Motorola/IBM PowerPC 603 or 603e
5263 604 Motorola PowerPC 604 or 604e
5264 750 Motorola/IBM PowerPC 750 or 750
5266 At the moment, this command just tells GDB what to name the
5267 special-purpose processor registers. Since almost all the affected
5268 registers are inaccessible to user-level programs, this command is
5269 only useful for remote debugging in its present form.
5273 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5274 more extensive support for HP-UX. Added features include shared
5275 library support, kernel threads and hardware watchpoints for 11.00,
5276 support for HP's ANSI C and C++ compilers, and a compatibility mode
5277 for xdb and dbx commands.
5281 HP's donation includes the new concept of catchpoints, which is a
5282 generalization of the old catch command. On HP-UX, it is now possible
5283 to catch exec, fork, and vfork, as well as library loading.
5285 This means that the existing catch command has changed; its first
5286 argument now specifies the type of catch to be set up. See the
5287 output of "help catch" for a list of catchpoint types.
5289 * Debugging across forks
5291 On HP-UX, you can choose which process to debug when a fork() happens
5296 HP has donated a curses-based terminal user interface (TUI). To get
5297 it, build with --enable-tui. Although this can be enabled for any
5298 configuration, at present it only works for native HP debugging.
5300 * GDB remote protocol additions
5302 A new protocol packet 'X' that writes binary data is now available.
5303 Default behavior is to try 'X', then drop back to 'M' if the stub
5304 fails to respond. The settable variable `remotebinarydownload'
5305 allows explicit control over the use of 'X'.
5307 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5308 full 64-bit address. The command
5310 set remoteaddresssize 32
5312 can be used to revert to the old behaviour. For existing remote stubs
5313 the change should not be noticed, as the additional address information
5316 In order to assist in debugging stubs, you may use the maintenance
5317 command `packet' to send any text string to the stub. For instance,
5319 maint packet heythere
5321 sends the packet "$heythere#<checksum>". Note that it is very easy to
5322 disrupt a debugging session by sending the wrong packet at the wrong
5325 The compare-sections command allows you to compare section data on the
5326 target to what is in the executable file without uploading or
5327 downloading, by comparing CRC checksums.
5329 * Tracing can collect general expressions
5331 You may now collect general expressions at tracepoints. This requires
5332 further additions to the target-side stub; see tracepoint.c and
5333 doc/agentexpr.texi for further details.
5335 * mask-address variable for Mips
5337 For Mips targets, you may control the zeroing of the upper 32 bits of
5338 a 64-bit address by entering `set mask-address on'. This is mainly
5339 of interest to users of embedded R4xxx and R5xxx processors.
5341 * Higher serial baud rates
5343 GDB's serial code now allows you to specify baud rates 57600, 115200,
5344 230400, and 460800 baud. (Note that your host system may not be able
5345 to achieve all of these rates.)
5349 The i960 configuration now includes an initial implementation of a
5350 builtin simulator, contributed by Jim Wilson.
5353 *** Changes in GDB-4.17:
5355 * New native configurations
5357 Alpha GNU/Linux alpha*-*-linux*
5358 Unixware 2.x i[3456]86-unixware2*
5359 Irix 6.x mips*-sgi-irix6*
5360 PowerPC GNU/Linux powerpc-*-linux*
5361 PowerPC Solaris powerpcle-*-solaris*
5362 Sparc GNU/Linux sparc-*-linux*
5363 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5367 Argonaut Risc Chip (ARC) arc-*-*
5368 Hitachi H8/300S h8300*-*-*
5369 Matsushita MN10200 w/simulator mn10200-*-*
5370 Matsushita MN10300 w/simulator mn10300-*-*
5371 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5372 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5373 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5374 Mitsubishi D10V w/simulator d10v-*-*
5375 Mitsubishi M32R/D w/simulator m32r-*-elf*
5376 Tsqware Sparclet sparclet-*-*
5377 NEC V850 w/simulator v850-*-*
5379 * New debugging protocols
5381 ARM with RDI protocol arm*-*-*
5382 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5383 DDB and LSI variants of PMON protocol mips*-*-*
5384 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5385 PowerPC with SDS protocol powerpc{,le}-*-eabi
5386 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5390 All configurations can now understand and use the DWARF 2 debugging
5391 format. The choice is automatic, if the symbol file contains DWARF 2
5396 GDB now includes basic Java language support. This support is
5397 only useful with Java compilers that produce native machine code.
5399 * solib-absolute-prefix and solib-search-path
5401 For SunOS and SVR4 shared libraries, you may now set the prefix for
5402 loading absolute shared library symbol files, and the search path for
5403 locating non-absolute shared library symbol files.
5405 * Live range splitting
5407 GDB can now effectively debug code for which GCC has performed live
5408 range splitting as part of its optimization. See gdb/doc/LRS for
5409 more details on the expected format of the stabs information.
5413 GDB's support for the GNU Hurd, including thread debugging, has been
5414 updated to work with current versions of the Hurd.
5418 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5419 instruction set. ARM GDB automatically detects when Thumb
5420 instructions are in use, and adjusts disassembly and backtracing
5425 GDB's MIPS target configurations now handle the MIP16 16-bit
5430 GDB now includes support for overlays; if an executable has been
5431 linked such that multiple sections are based at the same address, GDB
5432 will decide which section to use for symbolic info. You can choose to
5433 control the decision manually, using overlay commands, or implement
5434 additional target-side support and use "overlay load-target" to bring
5435 in the overlay mapping. Do "help overlay" for more detail.
5439 The command "info symbol <address>" displays information about
5440 the symbol at the specified address.
5444 The standard remote protocol now includes an extension that allows
5445 asynchronous collection and display of trace data. This requires
5446 extensive support in the target-side debugging stub. Tracing mode
5447 includes a new interaction mode in GDB and new commands: see the
5448 file tracepoint.c for more details.
5452 Configurations for embedded MIPS now include a simulator contributed
5453 by Cygnus Solutions. The simulator supports the instruction sets
5454 of most MIPS variants.
5458 Sparc configurations may now include the ERC32 simulator contributed
5459 by the European Space Agency. The simulator is not built into
5460 Sparc targets by default; configure with --enable-sim to include it.
5464 For target configurations that may include multiple variants of a
5465 basic architecture (such as MIPS and SH), you may now set the
5466 architecture explicitly. "set arch" sets, "info arch" lists
5467 the possible architectures.
5469 *** Changes in GDB-4.16:
5471 * New native configurations
5473 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5474 M68K NetBSD m68k-*-netbsd*
5475 PowerPC AIX 4.x powerpc-*-aix*
5476 PowerPC MacOS powerpc-*-macos*
5477 PowerPC Windows NT powerpcle-*-cygwin32
5478 RS/6000 AIX 4.x rs6000-*-aix4*
5482 ARM with RDP protocol arm-*-*
5483 I960 with MON960 i960-*-coff
5484 MIPS VxWorks mips*-*-vxworks*
5485 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5486 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5488 Matra Sparclet sparclet-*-*
5492 The powerpc-eabi configuration now includes the PSIM simulator,
5493 contributed by Andrew Cagney, with assistance from Mike Meissner.
5494 PSIM is a very elaborate model of the PowerPC, including not only
5495 basic instruction set execution, but also details of execution unit
5496 performance and I/O hardware. See sim/ppc/README for more details.
5500 GDB now works with Solaris 2.5.
5502 * Windows 95/NT native
5504 GDB will now work as a native debugger on Windows 95 and Windows NT.
5505 To build it from source, you must use the "gnu-win32" environment,
5506 which uses a DLL to emulate enough of Unix to run the GNU tools.
5507 Further information, binaries, and sources are available at
5508 ftp.cygnus.com, under pub/gnu-win32.
5510 * dont-repeat command
5512 If a user-defined command includes the command `dont-repeat', then the
5513 command will not be repeated if the user just types return. This is
5514 useful if the command is time-consuming to run, so that accidental
5515 extra keystrokes don't run the same command many times.
5517 * Send break instead of ^C
5519 The standard remote protocol now includes an option to send a break
5520 rather than a ^C to the target in order to interrupt it. By default,
5521 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5523 * Remote protocol timeout
5525 The standard remote protocol includes a new variable `remotetimeout'
5526 that allows you to set the number of seconds before GDB gives up trying
5527 to read from the target. The default value is 2.
5529 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5531 By default GDB will automatically keep track of objects as they are
5532 loaded and unloaded by the dynamic linker. By using the command `set
5533 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5534 when shared library events occur, thus allowing you to set breakpoints
5535 in shared libraries which are explicitly loaded by the inferior.
5537 Note this feature does not work on hpux8. On hpux9 you must link
5538 /usr/lib/end.o into your program. This feature should work
5539 automatically on hpux10.
5541 * Irix 5.x hardware watchpoint support
5543 Irix 5 configurations now support the use of hardware watchpoints.
5545 * Mips protocol "SYN garbage limit"
5547 When debugging a Mips target using the `target mips' protocol, you
5548 may set the number of characters that GDB will ignore by setting
5549 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5550 every character. The default value is 1050.
5552 * Recording and replaying remote debug sessions
5554 If you set `remotelogfile' to the name of a file, gdb will write to it
5555 a recording of a remote debug session. This recording may then be
5556 replayed back to gdb using "gdbreplay". See gdbserver/README for
5557 details. This is useful when you have a problem with GDB while doing
5558 remote debugging; you can make a recording of the session and send it
5559 to someone else, who can then recreate the problem.
5561 * Speedups for remote debugging
5563 GDB includes speedups for downloading and stepping MIPS systems using
5564 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5565 and more efficient S-record downloading.
5567 * Memory use reductions and statistics collection
5569 GDB now uses less memory and reports statistics about memory usage.
5570 Try the `maint print statistics' command, for example.
5572 *** Changes in GDB-4.15:
5574 * Psymtabs for XCOFF
5576 The symbol reader for AIX GDB now uses partial symbol tables. This
5577 can greatly improve startup time, especially for large executables.
5579 * Remote targets use caching
5581 Remote targets now use a data cache to speed up communication with the
5582 remote side. The data cache could lead to incorrect results because
5583 it doesn't know about volatile variables, thus making it impossible to
5584 debug targets which use memory mapped I/O devices. `set remotecache
5585 off' turns the the data cache off.
5587 * Remote targets may have threads
5589 The standard remote protocol now includes support for multiple threads
5590 in the target system, using new protocol commands 'H' and 'T'. See
5591 gdb/remote.c for details.
5595 If GDB is configured with `--enable-netrom', then it will include
5596 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5597 acts as though it is a bank of ROM on the target board, but you can
5598 write into it over the network. GDB's support consists only of
5599 support for fast loading into the emulated ROM; to debug, you must use
5600 another protocol, such as standard remote protocol. The usual
5601 sequence is something like
5603 target nrom <netrom-hostname>
5605 target remote <netrom-hostname>:1235
5609 GDB now includes support for the Apple Macintosh, as a host only. It
5610 may be run as either an MPW tool or as a standalone application, and
5611 it can debug through the serial port. All the usual GDB commands are
5612 available, but to the target command, you must supply "serial" as the
5613 device type instead of "/dev/ttyXX". See mpw-README in the main
5614 directory for more information on how to build. The MPW configuration
5615 scripts */mpw-config.in support only a few targets, and only the
5616 mips-idt-ecoff target has been tested.
5620 GDB configuration now uses autoconf. This is not user-visible,
5621 but does simplify configuration and building.
5625 GDB now supports hpux10.
5627 *** Changes in GDB-4.14:
5629 * New native configurations
5631 x86 FreeBSD i[345]86-*-freebsd
5632 x86 NetBSD i[345]86-*-netbsd
5633 NS32k NetBSD ns32k-*-netbsd
5634 Sparc NetBSD sparc-*-netbsd
5638 A29K VxWorks a29k-*-vxworks
5639 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5640 CPU32 EST-300 emulator m68*-*-est*
5641 PowerPC ELF powerpc-*-elf
5644 * Alpha OSF/1 support for procfs
5646 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5647 possible to attach to running processes. As the mounting of the /proc
5648 filesystem is optional on the Alpha, GDB automatically determines
5649 the availability of /proc during startup. This can lead to problems
5650 if /proc is unmounted after GDB has been started.
5652 * Arguments to user-defined commands
5654 User commands may accept up to 10 arguments separated by whitespace.
5655 Arguments are accessed within the user command via $arg0..$arg9. A
5658 print $arg0 + $arg1 + $arg2
5660 To execute the command use:
5663 Defines the command "adder" which prints the sum of its three arguments.
5664 Note the arguments are text substitutions, so they may reference variables,
5665 use complex expressions, or even perform inferior function calls.
5667 * New `if' and `while' commands
5669 This makes it possible to write more sophisticated user-defined
5670 commands. Both commands take a single argument, which is the
5671 expression to evaluate, and must be followed by the commands to
5672 execute, one per line, if the expression is nonzero, the list being
5673 terminated by the word `end'. The `if' command list may include an
5674 `else' word, which causes the following commands to be executed only
5675 if the expression is zero.
5677 * Fortran source language mode
5679 GDB now includes partial support for Fortran 77. It will recognize
5680 Fortran programs and can evaluate a subset of Fortran expressions, but
5681 variables and functions may not be handled correctly. GDB will work
5682 with G77, but does not yet know much about symbols emitted by other
5685 * Better HPUX support
5687 Most debugging facilities now work on dynamic executables for HPPAs
5688 running hpux9 or later. You can attach to running dynamically linked
5689 processes, but by default the dynamic libraries will be read-only, so
5690 for instance you won't be able to put breakpoints in them. To change
5691 that behavior do the following before running the program:
5697 This will cause the libraries to be mapped private and read-write.
5698 To revert to the normal behavior, do this:
5704 You cannot set breakpoints or examine data in the library until after
5705 the library is loaded if the function/data symbols do not have
5708 GDB can now also read debug symbols produced by the HP C compiler on
5709 HPPAs (sorry, no C++, Fortran or 68k support).
5711 * Target byte order now dynamically selectable
5713 You can choose which byte order to use with a target system, via the
5714 commands "set endian big" and "set endian little", and you can see the
5715 current setting by using "show endian". You can also give the command
5716 "set endian auto", in which case GDB will use the byte order
5717 associated with the executable. Currently, only embedded MIPS
5718 configurations support dynamic selection of target byte order.
5720 * New DOS host serial code
5722 This version uses DPMI interrupts to handle buffered I/O, so you
5723 no longer need to run asynctsr when debugging boards connected to
5726 *** Changes in GDB-4.13:
5728 * New "complete" command
5730 This lists all the possible completions for the rest of the line, if it
5731 were to be given as a command itself. This is intended for use by emacs.
5733 * Trailing space optional in prompt
5735 "set prompt" no longer adds a space for you after the prompt you set. This
5736 allows you to set a prompt which ends in a space or one that does not.
5738 * Breakpoint hit counts
5740 "info break" now displays a count of the number of times the breakpoint
5741 has been hit. This is especially useful in conjunction with "ignore"; you
5742 can ignore a large number of breakpoint hits, look at the breakpoint info
5743 to see how many times the breakpoint was hit, then run again, ignoring one
5744 less than that number, and this will get you quickly to the last hit of
5747 * Ability to stop printing at NULL character
5749 "set print null-stop" will cause GDB to stop printing the characters of
5750 an array when the first NULL is encountered. This is useful when large
5751 arrays actually contain only short strings.
5753 * Shared library breakpoints
5755 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5756 breakpoints in shared libraries before the executable is run.
5758 * Hardware watchpoints
5760 There is a new hardware breakpoint for the watch command for sparclite
5761 targets. See gdb/sparclite/hw_breakpoint.note.
5763 Hardware watchpoints are also now supported under GNU/Linux.
5767 Annotations have been added. These are for use with graphical interfaces,
5768 and are still experimental. Currently only gdba.el uses these.
5770 * Improved Irix 5 support
5772 GDB now works properly with Irix 5.2.
5774 * Improved HPPA support
5776 GDB now works properly with the latest GCC and GAS.
5778 * New native configurations
5780 Sequent PTX4 i[34]86-sequent-ptx4
5781 HPPA running OSF/1 hppa*-*-osf*
5782 Atari TT running SVR4 m68*-*-sysv4*
5783 RS/6000 LynxOS rs6000-*-lynxos*
5787 OS/9000 i[34]86-*-os9k
5788 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5791 * Hitachi SH7000 and E7000-PC ICE support
5793 There is now support for communicating with the Hitachi E7000-PC ICE.
5794 This is available automatically when GDB is configured for the SH.
5798 As usual, a variety of small fixes and improvements, both generic
5799 and configuration-specific. See the ChangeLog for more detail.
5801 *** Changes in GDB-4.12:
5803 * Irix 5 is now supported
5807 GDB-4.12 on the HPPA has a number of changes which make it unable
5808 to debug the output from the currently released versions of GCC and
5809 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5810 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5811 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5814 *** Changes in GDB-4.11:
5816 * User visible changes:
5820 The "set remotedebug" option is now consistent between the mips remote
5821 target, remote targets using the gdb-specific protocol, UDI (AMD's
5822 debug protocol for the 29k) and the 88k bug monitor. It is now an
5823 integer specifying a debug level (normally 0 or 1, but 2 means more
5824 debugging info for the mips target).
5826 * DEC Alpha native support
5828 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5829 debug info, but GDB works fairly well with the DEC compiler and should
5830 work with a future GCC release. See the README file for a few
5831 Alpha-specific notes.
5833 * Preliminary thread implementation
5835 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5837 * LynxOS native and target support for 386
5839 This release has been hosted on LynxOS 2.2, and also can be configured
5840 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5843 * Improvements in C++ mangling/demangling.
5845 This release has much better g++ debugging, specifically in name
5846 mangling/demangling, virtual function calls, print virtual table,
5847 call methods, ...etc.
5849 *** Changes in GDB-4.10:
5851 * User visible changes:
5853 Remote debugging using the GDB-specific (`target remote') protocol now
5854 supports the `load' command. This is only useful if you have some
5855 other way of getting the stub to the target system, and you can put it
5856 somewhere in memory where it won't get clobbered by the download.
5858 Filename completion now works.
5860 When run under emacs mode, the "info line" command now causes the
5861 arrow to point to the line specified. Also, "info line" prints
5862 addresses in symbolic form (as well as hex).
5864 All vxworks based targets now support a user settable option, called
5865 vxworks-timeout. This option represents the number of seconds gdb
5866 should wait for responses to rpc's. You might want to use this if
5867 your vxworks target is, perhaps, a slow software simulator or happens
5868 to be on the far side of a thin network line.
5872 This release contains support for using a DEC alpha as a GDB host for
5873 cross debugging. Native alpha debugging is not supported yet.
5876 *** Changes in GDB-4.9:
5880 This is the first GDB release which is accompanied by a matching testsuite.
5881 The testsuite requires installation of dejagnu, which should be available
5882 via ftp from most sites that carry GNU software.
5886 'Cfront' style demangling has had its name changed to 'ARM' style, to
5887 emphasize that it was written from the specifications in the C++ Annotated
5888 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
5889 disclaimers, it still generated too much confusion with users attempting to
5890 use gdb with AT&T cfront.
5894 GDB now uses a standard remote interface to a simulator library.
5895 So far, the library contains simulators for the Zilog Z8001/2, the
5896 Hitachi H8/300, H8/500 and Super-H.
5898 * New targets supported
5900 H8/300 simulator h8300-hitachi-hms or h8300hms
5901 H8/500 simulator h8500-hitachi-hms or h8500hms
5902 SH simulator sh-hitachi-hms or sh
5903 Z8000 simulator z8k-zilog-none or z8ksim
5904 IDT MIPS board over serial line mips-idt-ecoff
5906 Cross-debugging to GO32 targets is supported. It requires a custom
5907 version of the i386-stub.c module which is integrated with the
5908 GO32 memory extender.
5910 * New remote protocols
5912 MIPS remote debugging protocol.
5914 * New source languages supported
5916 This version includes preliminary support for Chill, a Pascal like language
5917 used by telecommunications companies. Chill support is also being integrated
5918 into the GNU compiler, but we don't know when it will be publically available.
5921 *** Changes in GDB-4.8:
5923 * HP Precision Architecture supported
5925 GDB now supports HP PA-RISC machines running HPUX. A preliminary
5926 version of this support was available as a set of patches from the
5927 University of Utah. GDB does not support debugging of programs
5928 compiled with the HP compiler, because HP will not document their file
5929 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
5930 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
5932 Many problems in the preliminary version have been fixed.
5934 * Faster and better demangling
5936 We have improved template demangling and fixed numerous bugs in the GNU style
5937 demangler. It can now handle type modifiers such as `static' or `const'. Wide
5938 character types (wchar_t) are now supported. Demangling of each symbol is now
5939 only done once, and is cached when the symbol table for a file is read in.
5940 This results in a small increase in memory usage for C programs, a moderate
5941 increase in memory usage for C++ programs, and a fantastic speedup in
5944 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
5945 from the specifications in the Annotated Reference Manual, which AT&T's
5946 compiler does not actually implement.
5948 * G++ multiple inheritance compiler problem
5950 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
5951 inheritance lattices was reworked to properly discover ambiguities. We
5952 recently found an example which causes this new algorithm to fail in a
5953 very subtle way, producing bad debug information for those classes.
5954 The file 'gcc.patch' (in this directory) can be applied to gcc to
5955 circumvent the problem. A future GCC release will contain a complete
5958 The previous G++ debug info problem (mentioned below for the gdb-4.7
5959 release) is fixed in gcc version 2.3.2.
5961 * Improved configure script
5963 The `configure' script will now attempt to guess your system type if
5964 you don't supply a host system type. The old scheme of supplying a
5965 host system triplet is preferable over using this. All the magic is
5966 done in the new `config.guess' script. Examine it for details.
5968 We have also brought our configure script much more in line with the FSF's
5969 version. It now supports the --with-xxx options. In particular,
5970 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
5971 The resulting GDB will not be able to read arbitrary object file formats --
5972 only the format ``expected'' to be used on the configured target system.
5973 We hope to make this the default in a future release.
5975 * Documentation improvements
5977 There's new internal documentation on how to modify GDB, and how to
5978 produce clean changes to the code. We implore people to read it
5979 before submitting changes.
5981 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
5982 M4 macros. The new texinfo.tex is provided in this release. Pre-built
5983 `info' files are also provided. To build `info' files from scratch,
5984 you will need the latest `makeinfo' release, which will be available in
5985 a future texinfo-X.Y release.
5987 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
5988 We're not sure exactly which versions have this problem, but it has
5989 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
5990 or better. If that isn't possible, there is a patch in
5991 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
5992 around this problem.
5996 GDB now supports array constants that can be used in expressions typed in by
5997 the user. The syntax is `{element, element, ...}'. Ie: you can now type
5998 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6001 The new directory `gdb/sparclite' contains a program that demonstrates
6002 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6004 * New native hosts supported
6006 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6007 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6009 * New targets supported
6011 AMD 29k family via UDI a29k-amd-udi or udi29k
6013 * New file formats supported
6015 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6016 HPUX core files, and SCO 3.2v2 core files.
6020 Attaching to processes now works again; thanks for the many bug reports.
6022 We have also stomped on a bunch of core dumps caused by
6023 printf_filtered("%s") problems.
6025 We eliminated a copyright problem on the rpc and ptrace header files
6026 for VxWorks, which was discovered at the last minute during the 4.7
6027 release. You should now be able to build a VxWorks GDB.
6029 You can now interrupt gdb while an attached process is running. This
6030 will cause the attached process to stop, and give control back to GDB.
6032 We fixed problems caused by using too many file descriptors
6033 for reading symbols from object files and libraries. This was
6034 especially a problem for programs that used many (~100) shared
6037 The `step' command now only enters a subroutine if there is line number
6038 information for the subroutine. Otherwise it acts like the `next'
6039 command. Previously, `step' would enter subroutines if there was
6040 any debugging information about the routine. This avoids problems
6041 when using `cc -g1' on MIPS machines.
6043 * Internal improvements
6045 GDB's internal interfaces have been improved to make it easier to support
6046 debugging of multiple languages in the future.
6048 GDB now uses a common structure for symbol information internally.
6049 Minimal symbols (derived from linkage symbols in object files), partial
6050 symbols (from a quick scan of debug information), and full symbols
6051 contain a common subset of information, making it easier to write
6052 shared code that handles any of them.
6054 * New command line options
6056 We now accept --silent as an alias for --quiet.
6060 The memory-mapped-malloc library is now licensed under the GNU Library
6061 General Public License.
6063 *** Changes in GDB-4.7:
6065 * Host/native/target split
6067 GDB has had some major internal surgery to untangle the support for
6068 hosts and remote targets. Now, when you configure GDB for a remote
6069 target, it will no longer load in all of the support for debugging
6070 local programs on the host. When fully completed and tested, this will
6071 ensure that arbitrary host/target combinations are possible.
6073 The primary conceptual shift is to separate the non-portable code in
6074 GDB into three categories. Host specific code is required any time GDB
6075 is compiled on that host, regardless of the target. Target specific
6076 code relates to the peculiarities of the target, but can be compiled on
6077 any host. Native specific code is everything else: it can only be
6078 built when the host and target are the same system. Child process
6079 handling and core file support are two common `native' examples.
6081 GDB's use of /proc for controlling Unix child processes is now cleaner.
6082 It has been split out into a single module under the `target_ops' vector,
6083 plus two native-dependent functions for each system that uses /proc.
6085 * New hosts supported
6087 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6088 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6089 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6091 * New targets supported
6093 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6094 68030 and CPU32 m68030-*-*, m68332-*-*
6096 * New native hosts supported
6098 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6099 (386bsd is not well tested yet)
6100 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6102 * New file formats supported
6104 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6105 supports reading of `a.out.adobe' object files, which are an a.out
6106 format extended with minimal information about multiple sections.
6110 `show copying' is the same as the old `info copying'.
6111 `show warranty' is the same as `info warrantee'.
6112 These were renamed for consistency. The old commands continue to work.
6114 `info handle' is a new alias for `info signals'.
6116 You can now define pre-command hooks, which attach arbitrary command
6117 scripts to any command. The commands in the hook will be executed
6118 prior to the user's command. You can also create a hook which will be
6119 executed whenever the program stops. See gdb.texinfo.
6123 We now deal with Cfront style name mangling, and can even extract type
6124 info from mangled symbols. GDB can automatically figure out which
6125 symbol mangling style your C++ compiler uses.
6127 Calling of methods and virtual functions has been improved as well.
6131 The crash that occured when debugging Sun Ansi-C compiled binaries is
6132 fixed. This was due to mishandling of the extra N_SO stabs output
6135 We also finally got Ultrix 4.2 running in house, and fixed core file
6136 support, with help from a dozen people on the net.
6138 John M. Farrell discovered that the reason that single-stepping was so
6139 slow on all of the Mips based platforms (primarily SGI and DEC) was
6140 that we were trying to demangle and lookup a symbol used for internal
6141 purposes on every instruction that was being stepped through. Changing
6142 the name of that symbol so that it couldn't be mistaken for a C++
6143 mangled symbol sped things up a great deal.
6145 Rich Pixley sped up symbol lookups in general by getting much smarter
6146 about when C++ symbol mangling is necessary. This should make symbol
6147 completion (TAB on the command line) much faster. It's not as fast as
6148 we'd like, but it's significantly faster than gdb-4.6.
6152 A new user controllable variable 'call_scratch_address' can
6153 specify the location of a scratch area to be used when GDB
6154 calls a function in the target. This is necessary because the
6155 usual method of putting the scratch area on the stack does not work
6156 in systems that have separate instruction and data spaces.
6158 We integrated changes to support the 29k UDI (Universal Debugger
6159 Interface), but discovered at the last minute that we didn't have all
6160 of the appropriate copyright paperwork. We are working with AMD to
6161 resolve this, and hope to have it available soon.
6165 We have sped up the remote serial line protocol, especially for targets
6166 with lots of registers. It now supports a new `expedited status' ('T')
6167 message which can be used in place of the existing 'S' status message.
6168 This allows the remote stub to send only the registers that GDB
6169 needs to make a quick decision about single-stepping or conditional
6170 breakpoints, eliminating the need to fetch the entire register set for
6171 each instruction being stepped through.
6173 The GDB remote serial protocol now implements a write-through cache for
6174 registers, only re-reading the registers if the target has run.
6176 There is also a new remote serial stub for SPARC processors. You can
6177 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6178 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6179 processor with a serial port.
6183 Configure.in files have become much easier to read and modify. A new
6184 `table driven' format makes it more obvious what configurations are
6185 supported, and what files each one uses.
6189 There is a new opcodes library which will eventually contain all of the
6190 disassembly routines and opcode tables. At present, it only contains
6191 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6192 disassembler (binutils/objdump) to share these routines.
6194 The libiberty library is now copylefted under the GNU Library General
6195 Public License. This allows more liberal use, and was done so libg++
6196 can use it. This makes no difference to GDB, since the Library License
6197 grants all the rights from the General Public License.
6201 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6202 reference to the stabs symbol info used by the debugger. It is (as far
6203 as we know) the only published document on this fascinating topic. We
6204 encourage you to read it, compare it to the stabs information on your
6205 system, and send improvements on the document in general (to
6206 bug-gdb@prep.ai.mit.edu).
6208 And, of course, many bugs have been fixed.
6211 *** Changes in GDB-4.6:
6213 * Better support for C++ function names
6215 GDB now accepts as input the "demangled form" of C++ overloaded function
6216 names and member function names, and can do command completion on such names
6217 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6218 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6219 Make use of command completion, it is your friend.
6221 GDB also now accepts a variety of C++ mangled symbol formats. They are
6222 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6223 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6224 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6225 for the list of formats.
6227 * G++ symbol mangling problem
6229 Recent versions of gcc have a bug in how they emit debugging information for
6230 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6231 directory) can be applied to gcc to fix the problem. Alternatively, if you
6232 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6233 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6234 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6237 * New 'maintenance' command
6239 All of the commands related to hacking GDB internals have been moved out of
6240 the main command set, and now live behind the 'maintenance' command. This
6241 can also be abbreviated as 'mt'. The following changes were made:
6243 dump-me -> maintenance dump-me
6244 info all-breakpoints -> maintenance info breakpoints
6245 printmsyms -> maintenance print msyms
6246 printobjfiles -> maintenance print objfiles
6247 printpsyms -> maintenance print psymbols
6248 printsyms -> maintenance print symbols
6250 The following commands are new:
6252 maintenance demangle Call internal GDB demangler routine to
6253 demangle a C++ link name and prints the result.
6254 maintenance print type Print a type chain for a given symbol
6256 * Change to .gdbinit file processing
6258 We now read the $HOME/.gdbinit file before processing the argv arguments
6259 (e.g. reading symbol files or core files). This allows global parameters to
6260 be set, which will apply during the symbol reading. The ./.gdbinit is still
6261 read after argv processing.
6263 * New hosts supported
6265 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6267 GNU/Linux support i386-unknown-linux or linux
6269 We are also including code to support the HP/PA running BSD and HPUX. This
6270 is almost guaranteed not to work, as we didn't have time to test or build it
6271 for this release. We are including it so that the more adventurous (or
6272 masochistic) of you can play with it. We also had major problems with the
6273 fact that the compiler that we got from HP doesn't support the -g option.
6276 * New targets supported
6278 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6280 * More smarts about finding #include files
6282 GDB now remembers the compilation directory for all include files, and for
6283 all files from which C is generated (like yacc and lex sources). This
6284 greatly improves GDB's ability to find yacc/lex sources, and include files,
6285 especially if you are debugging your program from a directory different from
6286 the one that contains your sources.
6288 We also fixed a bug which caused difficulty with listing and setting
6289 breakpoints in include files which contain C code. (In the past, you had to
6290 try twice in order to list an include file that you hadn't looked at before.)
6292 * Interesting infernals change
6294 GDB now deals with arbitrary numbers of sections, where the symbols for each
6295 section must be relocated relative to that section's landing place in the
6296 target's address space. This work was needed to support ELF with embedded
6297 stabs used by Solaris-2.0.
6299 * Bug fixes (of course!)
6301 There have been loads of fixes for the following things:
6302 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6303 i960, stabs, DOS(GO32), procfs, etc...
6305 See the ChangeLog for details.
6307 *** Changes in GDB-4.5:
6309 * New machines supported (host and target)
6311 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6313 SGI Irix-4.x mips-sgi-irix4 or iris4
6315 * New malloc package
6317 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6318 Mmalloc is capable of handling mutiple heaps of memory. It is also
6319 capable of saving a heap to a file, and then mapping it back in later.
6320 This can be used to greatly speedup the startup of GDB by using a
6321 pre-parsed symbol table which lives in a mmalloc managed heap. For
6322 more details, please read mmalloc/mmalloc.texi.
6326 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6327 'help info proc' for details.
6329 * MIPS ecoff symbol table format
6331 The code that reads MIPS symbol table format is now supported on all hosts.
6332 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6335 * File name changes for MS-DOS
6337 Many files in the config directories have been renamed to make it easier to
6338 support GDB on MS-DOSe systems (which have very restrictive file name
6339 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6340 environment) is close to working but has some remaining problems. Note
6341 that debugging of DOS programs is not supported, due to limitations
6342 in the ``operating system'', but it can be used to host cross-debugging.
6344 * Cross byte order fixes
6346 Many fixes have been made to support cross debugging of Sparc and MIPS
6347 targets from hosts whose byte order differs.
6349 * New -mapped and -readnow options
6351 If memory-mapped files are available on your system through the 'mmap'
6352 system call, you can use the -mapped option on the `file' or
6353 `symbol-file' commands to cause GDB to write the symbols from your
6354 program into a reusable file. If the program you are debugging is
6355 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6356 Future GDB debugging sessions will notice the presence of this file,
6357 and will quickly map in symbol information from it, rather than reading
6358 the symbol table from the executable program. Using the '-mapped'
6359 option in a GDB `file' or `symbol-file' command has the same effect as
6360 starting GDB with the '-mapped' command-line option.
6362 You can cause GDB to read the entire symbol table immediately by using
6363 the '-readnow' option with any of the commands that load symbol table
6364 information (or on the GDB command line). This makes the command
6365 slower, but makes future operations faster.
6367 The -mapped and -readnow options are typically combined in order to
6368 build a `fred.syms' file that contains complete symbol information.
6369 A simple GDB invocation to do nothing but build a `.syms' file for future
6372 gdb -batch -nx -mapped -readnow programname
6374 The `.syms' file is specific to the host machine on which GDB is run.
6375 It holds an exact image of GDB's internal symbol table. It cannot be
6376 shared across multiple host platforms.
6378 * longjmp() handling
6380 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6381 siglongjmp() without losing control. This feature has not yet been ported to
6382 all systems. It currently works on many 386 platforms, all MIPS-based
6383 platforms (SGI, DECstation, etc), and Sun3/4.
6387 Preliminary work has been put in to support the new Solaris OS from Sun. At
6388 this time, it can control and debug processes, but it is not capable of
6393 As always, many many bug fixes. The major areas were with g++, and mipsread.
6394 People using the MIPS-based platforms should experience fewer mysterious
6395 crashes and trashed symbol tables.
6397 *** Changes in GDB-4.4:
6399 * New machines supported (host and target)
6401 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6403 BSD Reno on Vax vax-dec-bsd
6404 Ultrix on Vax vax-dec-ultrix
6406 * New machines supported (target)
6408 AMD 29000 embedded, using EBMON a29k-none-none
6412 GDB continues to improve its handling of C++. `References' work better.
6413 The demangler has also been improved, and now deals with symbols mangled as
6414 per the Annotated C++ Reference Guide.
6416 GDB also now handles `stabs' symbol information embedded in MIPS
6417 `ecoff' symbol tables. Since the ecoff format was not easily
6418 extensible to handle new languages such as C++, this appeared to be a
6419 good way to put C++ debugging info into MIPS binaries. This option
6420 will be supported in the GNU C compiler, version 2, when it is
6423 * New features for SVR4
6425 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6426 shared libraries. Debugging dynamically linked programs should present
6427 only minor differences from debugging statically linked programs.
6429 The `info proc' command will print out information about any process
6430 on an SVR4 system (including the one you are debugging). At the moment,
6431 it prints the address mappings of the process.
6433 If you bring up GDB on another SVR4 system, please send mail to
6434 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6436 * Better dynamic linking support in SunOS
6438 Reading symbols from shared libraries which contain debugging symbols
6439 now works properly. However, there remain issues such as automatic
6440 skipping of `transfer vector' code during function calls, which
6441 make it harder to debug code in a shared library, than to debug the
6442 same code linked statically.
6446 GDB is now using the latest `getopt' routines from the FSF. This
6447 version accepts the -- prefix for options with long names. GDB will
6448 continue to accept the old forms (-option and +option) as well.
6449 Various single letter abbreviations for options have been explicity
6450 added to the option table so that they won't get overshadowed in the
6451 future by other options that begin with the same letter.
6455 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6456 Many assorted bugs have been handled. Many more remain to be handled.
6457 See the various ChangeLog files (primarily in gdb and bfd) for details.
6460 *** Changes in GDB-4.3:
6462 * New machines supported (host and target)
6464 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6465 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6466 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6468 * Almost SCO Unix support
6470 We had hoped to support:
6471 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6472 (except for core file support), but we discovered very late in the release
6473 that it has problems with process groups that render gdb unusable. Sorry
6474 about that. I encourage people to fix it and post the fixes.
6476 * Preliminary ELF and DWARF support
6478 GDB can read ELF object files on System V Release 4, and can handle
6479 debugging records for C, in DWARF format, in ELF files. This support
6480 is preliminary. If you bring up GDB on another SVR4 system, please
6481 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6486 GDB now uses the latest `readline' library. One user-visible change
6487 is that two tabs will list possible command completions, which previously
6488 required typing M-? (meta-question mark, or ESC ?).
6492 The `stepi' bug that many of you noticed has been squashed.
6493 Many bugs in C++ have been handled. Many more remain to be handled.
6494 See the various ChangeLog files (primarily in gdb and bfd) for details.
6496 * State of the MIPS world (in case you wondered):
6498 GDB can understand the symbol tables emitted by the compilers
6499 supplied by most vendors of MIPS-based machines, including DEC. These
6500 symbol tables are in a format that essentially nobody else uses.
6502 Some versions of gcc come with an assembler post-processor called
6503 mips-tfile. This program is required if you want to do source-level
6504 debugging of gcc-compiled programs. I believe FSF does not ship
6505 mips-tfile with gcc version 1, but it will eventually come with gcc
6508 Debugging of g++ output remains a problem. g++ version 1.xx does not
6509 really support it at all. (If you're lucky, you should be able to get
6510 line numbers and stack traces to work, but no parameters or local
6511 variables.) With some work it should be possible to improve the
6514 When gcc version 2 is released, you will have somewhat better luck.
6515 However, even then you will get confusing results for inheritance and
6518 We will eventually provide full debugging of g++ output on
6519 DECstations. This will probably involve some kind of stabs-in-ecoff
6520 encapulation, but the details have not been worked out yet.
6523 *** Changes in GDB-4.2:
6525 * Improved configuration
6527 Only one copy of `configure' exists now, and it is not self-modifying.
6528 Porting BFD is simpler.
6532 The `step' and `next' commands now only stop at the first instruction
6533 of a source line. This prevents the multiple stops that used to occur
6534 in switch statements, for-loops, etc. `Step' continues to stop if a
6535 function that has debugging information is called within the line.
6539 Lots of small bugs fixed. More remain.
6541 * New host supported (not target)
6543 Intel 386 PC clone running Mach i386-none-mach
6546 *** Changes in GDB-4.1:
6548 * Multiple source language support
6550 GDB now has internal scaffolding to handle several source languages.
6551 It determines the type of each source file from its filename extension,
6552 and will switch expression parsing and number formatting to match the
6553 language of the function in the currently selected stack frame.
6554 You can also specifically set the language to be used, with
6555 `set language c' or `set language modula-2'.
6559 GDB now has preliminary support for the GNU Modula-2 compiler,
6560 currently under development at the State University of New York at
6561 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6562 continue through the fall of 1991 and into 1992.
6564 Other Modula-2 compilers are currently not supported, and attempting to
6565 debug programs compiled with them will likely result in an error as the
6566 symbol table is read. Feel free to work on it, though!
6568 There are hooks in GDB for strict type checking and range checking,
6569 in the `Modula-2 philosophy', but they do not currently work.
6573 GDB can now write to executable and core files (e.g. patch
6574 a variable's value). You must turn this switch on, specify
6575 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6576 by assigning a new value to a variable. Modifications take
6579 * Automatic SunOS shared library reading
6581 When you run your program, GDB automatically determines where its
6582 shared libraries (if any) have been loaded, and reads their symbols.
6583 The `share' command is no longer needed. This also works when
6584 examining core files.
6588 You can specify the number of lines that the `list' command shows.
6591 * New machines supported (host and target)
6593 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6594 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6595 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6597 * New hosts supported (not targets)
6599 IBM RT/PC: romp-ibm-aix or rtpc
6601 * New targets supported (not hosts)
6603 AMD 29000 embedded with COFF a29k-none-coff
6604 AMD 29000 embedded with a.out a29k-none-aout
6605 Ultracomputer remote kernel debug a29k-nyu-kern
6607 * New remote interfaces
6613 *** Changes in GDB-4.0:
6617 Wide output is wrapped at good places to make the output more readable.
6619 Gdb now supports cross-debugging from a host machine of one type to a
6620 target machine of another type. Communication with the target system
6621 is over serial lines. The ``target'' command handles connecting to the
6622 remote system; the ``load'' command will download a program into the
6623 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6624 also supports debugging of realtime processes running under VxWorks,
6625 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6626 stub on the target system.
6628 New CPUs supported include the AMD 29000 and Intel 960.
6630 GDB now reads object files and symbol tables via a ``binary file''
6631 library, which allows a single copy of GDB to debug programs of multiple
6632 object file types such as a.out and coff.
6634 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6635 refcard.dvi and refcard.ps are available to format it).
6638 * Control-Variable user interface simplified
6640 All variables that control the operation of the debugger can be set
6641 by the ``set'' command, and displayed by the ``show'' command.
6643 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6644 ``Show prompt'' produces the response:
6645 Gdb's prompt is new-gdb=>.
6647 What follows are the NEW set commands. The command ``help set'' will
6648 print a complete list of old and new set commands. ``help set FOO''
6649 will give a longer description of the variable FOO. ``show'' will show
6650 all of the variable descriptions and their current settings.
6652 confirm on/off: Enables warning questions for operations that are
6653 hard to recover from, e.g. rerunning the program while
6654 it is already running. Default is ON.
6656 editing on/off: Enables EMACS style command line editing
6657 of input. Previous lines can be recalled with
6658 control-P, the current line can be edited with control-B,
6659 you can search for commands with control-R, etc.
6662 history filename NAME: NAME is where the gdb command history
6663 will be stored. The default is .gdb_history,
6664 or the value of the environment variable
6667 history size N: The size, in commands, of the command history. The
6668 default is 256, or the value of the environment variable
6671 history save on/off: If this value is set to ON, the history file will
6672 be saved after exiting gdb. If set to OFF, the
6673 file will not be saved. The default is OFF.
6675 history expansion on/off: If this value is set to ON, then csh-like
6676 history expansion will be performed on
6677 command line input. The default is OFF.
6679 radix N: Sets the default radix for input and output. It can be set
6680 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6681 in the current radix, so "set radix 10" is always a no-op.
6683 height N: This integer value is the number of lines on a page. Default
6684 is 24, the current `stty rows'' setting, or the ``li#''
6685 setting from the termcap entry matching the environment
6688 width N: This integer value is the number of characters on a line.
6689 Default is 80, the current `stty cols'' setting, or the ``co#''
6690 setting from the termcap entry matching the environment
6693 Note: ``set screensize'' is obsolete. Use ``set height'' and
6694 ``set width'' instead.
6696 print address on/off: Print memory addresses in various command displays,
6697 such as stack traces and structure values. Gdb looks
6698 more ``symbolic'' if you turn this off; it looks more
6699 ``machine level'' with it on. Default is ON.
6701 print array on/off: Prettyprint arrays. New convenient format! Default
6704 print demangle on/off: Print C++ symbols in "source" form if on,
6707 print asm-demangle on/off: Same, for assembler level printouts
6710 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6713 * Support for Epoch Environment.
6715 The epoch environment is a version of Emacs v18 with windowing. One
6716 new command, ``inspect'', is identical to ``print'', except that if you
6717 are running in the epoch environment, the value is printed in its own
6721 * Support for Shared Libraries
6723 GDB can now debug programs and core files that use SunOS shared libraries.
6724 Symbols from a shared library cannot be referenced
6725 before the shared library has been linked with the program (this
6726 happens after you type ``run'' and before the function main() is entered).
6727 At any time after this linking (including when examining core files
6728 from dynamically linked programs), gdb reads the symbols from each
6729 shared library when you type the ``sharedlibrary'' command.
6730 It can be abbreviated ``share''.
6732 sharedlibrary REGEXP: Load shared object library symbols for files
6733 matching a unix regular expression. No argument
6734 indicates to load symbols for all shared libraries.
6736 info sharedlibrary: Status of loaded shared libraries.
6741 A watchpoint stops execution of a program whenever the value of an
6742 expression changes. Checking for this slows down execution
6743 tremendously whenever you are in the scope of the expression, but is
6744 quite useful for catching tough ``bit-spreader'' or pointer misuse
6745 problems. Some machines such as the 386 have hardware for doing this
6746 more quickly, and future versions of gdb will use this hardware.
6748 watch EXP: Set a watchpoint (breakpoint) for an expression.
6750 info watchpoints: Information about your watchpoints.
6752 delete N: Deletes watchpoint number N (same as breakpoints).
6753 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6754 enable N: Re-enables watchpoint number N (same as breakpoints).
6757 * C++ multiple inheritance
6759 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6762 * C++ exception handling
6764 Gdb now supports limited C++ exception handling. Besides the existing
6765 ability to breakpoint on an exception handler, gdb can breakpoint on
6766 the raising of an exception (before the stack is peeled back to the
6769 catch FOO: If there is a FOO exception handler in the dynamic scope,
6770 set a breakpoint to catch exceptions which may be raised there.
6771 Multiple exceptions (``catch foo bar baz'') may be caught.
6773 info catch: Lists all exceptions which may be caught in the
6774 current stack frame.
6777 * Minor command changes
6779 The command ``call func (arg, arg, ...)'' now acts like the print
6780 command, except it does not print or save a value if the function's result
6781 is void. This is similar to dbx usage.
6783 The ``up'' and ``down'' commands now always print the frame they end up
6784 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6785 frames without printing.
6787 * New directory command
6789 'dir' now adds directories to the FRONT of the source search path.
6790 The path starts off empty. Source files that contain debug information
6791 about the directory in which they were compiled can be found even
6792 with an empty path; Sun CC and GCC include this information. If GDB can't
6793 find your source file in the current directory, type "dir .".
6795 * Configuring GDB for compilation
6797 For normal use, type ``./configure host''. See README or gdb.texinfo
6800 GDB now handles cross debugging. If you are remotely debugging between
6801 two different machines, type ``./configure host -target=targ''.
6802 Host is the machine where GDB will run; targ is the machine
6803 where the program that you are debugging will run.