1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.1
6 * The commands 'info variables/functions/types' now show the source line
7 numbers of symbol definitions when available.
9 * 'info proc' now works on running processes on FreeBSD systems and core
10 files created on FreeBSD systems.
16 Control display of debugging info regarding the FreeBSD native target.
18 set|show varsize-limit
19 This new setting allows the user to control the maximum size of Ada
20 objects being printed when those objects have a variable type,
21 instead of that maximum size being hardcoded to 65536 bytes.
23 set|show record btrace cpu
24 Controls the processor to be used for enabling errata workarounds for
29 RiscV ELF riscv*-*-elf
31 * Removed targets and native configurations
33 m88k running OpenBSD m88*-*-openbsd*
35 *** Changes in GDB 8.1
37 * GDB now supports dynamically creating arbitrary register groups specified
38 in XML target descriptions. This allows for finer grain grouping of
39 registers on systems with a large amount of registers.
41 * The 'ptype' command now accepts a '/o' flag, which prints the
42 offsets and sizes of fields in a struct, like the pahole(1) tool.
44 * New "--readnever" command line option instructs GDB to not read each
45 symbol file's symbolic debug information. This makes startup faster
46 but at the expense of not being able to perform symbolic debugging.
47 This option is intended for use cases where symbolic debugging will
48 not be used, e.g., when you only need to dump the debuggee's core.
50 * GDB now uses the GNU MPFR library, if available, to emulate target
51 floating-point arithmetic during expression evaluation when the target
52 uses different floating-point formats than the host. At least version
53 3.1 of GNU MPFR is required.
55 * GDB now supports access to the guarded-storage-control registers and the
56 software-based guarded-storage broadcast control registers on IBM z14.
58 * On Unix systems, GDB now supports transmitting environment variables
59 that are to be set or unset to GDBserver. These variables will
60 affect the environment to be passed to the remote inferior.
62 To inform GDB of environment variables that are to be transmitted to
63 GDBserver, use the "set environment" command. Only user set
64 environment variables are sent to GDBserver.
66 To inform GDB of environment variables that are to be unset before
67 the remote inferior is started by the GDBserver, use the "unset
70 * Completion improvements
72 ** GDB can now complete function parameters in linespecs and
73 explicit locations without quoting. When setting breakpoints,
74 quoting around functions names to help with TAB-completion is
75 generally no longer necessary. For example, this now completes
78 (gdb) b function(in[TAB]
81 Related, GDB is no longer confused with completing functions in
82 C++ anonymous namespaces:
85 (gdb) b (anonymous namespace)::[TAB][TAB]
86 (anonymous namespace)::a_function()
87 (anonymous namespace)::b_function()
89 ** GDB now has much improved linespec and explicit locations TAB
90 completion support, that better understands what you're
91 completing and offers better suggestions. For example, GDB no
92 longer offers data symbols as possible completions when you're
95 ** GDB now TAB-completes label symbol names.
97 ** The "complete" command now mimics TAB completion accurately.
99 * New command line options (gcore)
102 Dump all memory mappings.
104 * Breakpoints on C++ functions are now set on all scopes by default
106 By default, breakpoints on functions/methods are now interpreted as
107 specifying all functions with the given name ignoring missing
108 leading scopes (namespaces and classes).
110 For example, assuming a C++ program with symbols named:
115 both commands "break func()" and "break B::func()" set a breakpoint
118 You can use the new flag "-qualified" to override this. This makes
119 GDB interpret the specified function name as a complete
120 fully-qualified name instead. For example, using the same C++
121 program, the "break -q B::func" command sets a breakpoint on
122 "B::func", only. A parameter has been added to the Python
123 gdb.Breakpoint constructor to achieve the same result when creating
124 a breakpoint from Python.
126 * Breakpoints on functions marked with C++ ABI tags
128 GDB can now set breakpoints on functions marked with C++ ABI tags
129 (e.g., [abi:cxx11]). See here for a description of ABI tags:
130 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
132 Functions with a C++11 abi tag are demangled/displayed like this:
134 function[abi:cxx11](int)
137 You can now set a breakpoint on such functions simply as if they had
140 (gdb) b function(int)
142 Or if you need to disambiguate between tags, like:
144 (gdb) b function[abi:other_tag](int)
146 Tab completion was adjusted accordingly as well.
150 ** New events gdb.new_inferior, gdb.inferior_deleted, and
151 gdb.new_thread are emitted. See the manual for further
152 description of these.
154 ** A new function, "gdb.rbreak" has been added to the Python API.
155 This function allows the setting of a large number of breakpoints
156 via a regex pattern in Python. See the manual for further details.
158 ** Python breakpoints can now accept explicit locations. See the
159 manual for a further description of this feature.
162 * New features in the GDB remote stub, GDBserver
164 ** GDBserver is now able to start inferior processes with a
165 specified initial working directory.
167 The user can set the desired working directory to be used from
168 GDB using the new "set cwd" command.
170 ** New "--selftest" command line option runs some GDBserver self
171 tests. These self tests are disabled in releases.
173 ** On Unix systems, GDBserver now does globbing expansion and variable
174 substitution in inferior command line arguments.
176 This is done by starting inferiors using a shell, like GDB does.
177 See "set startup-with-shell" in the user manual for how to disable
178 this from GDB when using "target extended-remote". When using
179 "target remote", you can disable the startup with shell by using the
180 new "--no-startup-with-shell" GDBserver command line option.
182 ** On Unix systems, GDBserver now supports receiving environment
183 variables that are to be set or unset from GDB. These variables
184 will affect the environment to be passed to the inferior.
186 * When catching an Ada exception raised with a message, GDB now prints
187 the message in the catchpoint hit notification. In GDB/MI mode, that
188 information is provided as an extra field named "exception-message"
189 in the *stopped notification.
191 * Trait objects can now be inspected When debugging Rust code. This
192 requires compiler support which will appear in Rust 1.24.
196 QEnvironmentHexEncoded
197 Inform GDBserver of an environment variable that is to be passed to
198 the inferior when starting it.
201 Inform GDBserver of an environment variable that is to be unset
202 before starting the remote inferior.
205 Inform GDBserver that the environment should be reset (i.e.,
206 user-set environment variables should be unset).
209 Indicates whether the inferior must be started with a shell or not.
212 Tell GDBserver that the inferior to be started should use a specific
215 * The "maintenance print c-tdesc" command now takes an optional
216 argument which is the file name of XML target description.
218 * The "maintenance selftest" command now takes an optional argument to
219 filter the tests to be run.
221 * The "enable", and "disable" commands now accept a range of
222 breakpoint locations, e.g. "enable 1.3-5".
227 Set and show the current working directory for the inferior.
230 Set and show compilation command used for compiling and injecting code
231 with the 'compile' commands.
233 set debug separate-debug-file
234 show debug separate-debug-file
235 Control the display of debug output about separate debug file search.
237 set dump-excluded-mappings
238 show dump-excluded-mappings
239 Control whether mappings marked with the VM_DONTDUMP flag should be
240 dumped when generating a core file.
243 List the registered selftests.
246 Start the debugged program stopping at the first instruction.
249 Control display of debugging messages related to OpenRISC targets.
251 set|show print type nested-type-limit
252 Set and show the limit of nesting level for nested types that the
253 type printer will show.
255 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
258 * Safer/improved support for debugging with no debug info
260 GDB no longer assumes functions with no debug information return
263 This means that GDB now refuses to call such functions unless you
264 tell it the function's type, by either casting the call to the
265 declared return type, or by casting the function to a function
266 pointer of the right type, and calling that:
268 (gdb) p getenv ("PATH")
269 'getenv' has unknown return type; cast the call to its declared return type
270 (gdb) p (char *) getenv ("PATH")
271 $1 = 0x7fffffffe "/usr/local/bin:/"...
272 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
273 $2 = 0x7fffffffe "/usr/local/bin:/"...
275 Similarly, GDB no longer assumes that global variables with no debug
276 info have type 'int', and refuses to print the variable's value
277 unless you tell it the variable's type:
280 'var' has unknown type; cast it to its declared type
284 * New native configurations
286 FreeBSD/aarch64 aarch64*-*-freebsd*
287 FreeBSD/arm arm*-*-freebsd*
291 FreeBSD/aarch64 aarch64*-*-freebsd*
292 FreeBSD/arm arm*-*-freebsd*
293 OpenRISC ELF or1k*-*-elf
295 * Removed targets and native configurations
297 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
299 *** Changes in GDB 8.0
301 * GDB now supports access to the PKU register on GNU/Linux. The register is
302 added by the Memory Protection Keys for Userspace feature which will be
303 available in future Intel CPUs.
305 * GDB now supports C++11 rvalue references.
309 ** New functions to start, stop and access a running btrace recording.
310 ** Rvalue references are now supported in gdb.Type.
312 * GDB now supports recording and replaying rdrand and rdseed Intel 64
315 * Building GDB and GDBserver now requires a C++11 compiler.
317 For example, GCC 4.8 or later.
319 It is no longer possible to build GDB or GDBserver with a C
320 compiler. The --disable-build-with-cxx configure option has been
323 * Building GDB and GDBserver now requires GNU make >= 3.81.
325 It is no longer supported to build GDB or GDBserver with another
326 implementation of the make program or an earlier version of GNU make.
328 * Native debugging on MS-Windows supports command-line redirection
330 Command-line arguments used for starting programs on MS-Windows can
331 now include redirection symbols supported by native Windows shells,
332 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
333 as "run", "start", and "set args", as well as the corresponding MI
336 * Support for thread names on MS-Windows.
338 GDB now catches and handles the special exception that programs
339 running on MS-Windows use to assign names to threads in the
342 * Support for Java programs compiled with gcj has been removed.
344 * User commands now accept an unlimited number of arguments.
345 Previously, only up to 10 was accepted.
347 * The "eval" command now expands user-defined command arguments.
349 This makes it easier to process a variable number of arguments:
354 eval "print $arg%d", $i
359 * Target descriptions can now describe registers for sparc32 and sparc64.
361 * GDB now supports DWARF version 5 (debug information format).
362 Its .debug_names index is not yet supported.
364 * New native configurations
366 FreeBSD/mips mips*-*-freebsd
370 Synopsys ARC arc*-*-elf32
371 FreeBSD/mips mips*-*-freebsd
373 * Removed targets and native configurations
375 Alpha running FreeBSD alpha*-*-freebsd*
376 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
381 Erases all the flash memory regions reported by the target.
383 maint print arc arc-instruction address
384 Print internal disassembler information about instruction at a given address.
388 set disassembler-options
389 show disassembler-options
390 Controls the passing of target specific information to the disassembler.
391 If it is necessary to specify more than one disassembler option then
392 multiple options can be placed together into a comma separated list.
393 The default value is the empty string. Currently, the only supported
394 targets are ARM, PowerPC and S/390.
399 Erases all the flash memory regions reported by the target. This is
400 equivalent to the CLI command flash-erase.
402 -file-list-shared-libraries
403 List the shared libraries in the program. This is
404 equivalent to the CLI command "info shared".
407 Catchpoints stopping the program when Ada exceptions are
408 handled. This is equivalent to the CLI command "catch handlers".
410 *** Changes in GDB 7.12
412 * GDB and GDBserver now build with a C++ compiler by default.
414 The --enable-build-with-cxx configure option is now enabled by
415 default. One must now explicitly configure with
416 --disable-build-with-cxx in order to build with a C compiler. This
417 option will be removed in a future release.
419 * GDBserver now supports recording btrace without maintaining an active
422 * GDB now supports a negative repeat count in the 'x' command to examine
423 memory backward from the given address. For example:
426 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
427 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
428 (gdb) x/-5i 0x0000000000400580
429 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
430 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
431 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
432 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
433 0x40057b <main(int, char**)+25>:
434 callq 0x400536 <Func1(int, char const*)>
436 * Fortran: Support structures with fields of dynamic types and
437 arrays of dynamic types.
439 * The symbol dumping maintenance commands have new syntax.
440 maint print symbols [-pc address] [--] [filename]
441 maint print symbols [-objfile objfile] [-source source] [--] [filename]
442 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
443 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
444 maint print msymbols [-objfile objfile] [--] [filename]
446 * GDB now supports multibit bitfields and enums in target register
449 * New Python-based convenience function $_as_string(val), which returns
450 the textual representation of a value. This function is especially
451 useful to obtain the text label of an enum value.
453 * Intel MPX bound violation handling.
455 Segmentation faults caused by a Intel MPX boundary violation
456 now display the kind of violation (upper or lower), the memory
457 address accessed and the memory bounds, along with the usual
458 signal received and code location.
462 Program received signal SIGSEGV, Segmentation fault
463 Upper bound violation while accessing address 0x7fffffffc3b3
464 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
465 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
467 * Rust language support.
468 GDB now supports debugging programs written in the Rust programming
469 language. See https://www.rust-lang.org/ for more information about
472 * Support for running interpreters on specified input/output devices
474 GDB now supports a new mechanism that allows frontends to provide
475 fully featured GDB console views, as a better alternative to
476 building such views on top of the "-interpreter-exec console"
477 command. See the new "new-ui" command below. With that command,
478 frontends can now start GDB in the traditional command-line mode
479 running in an embedded terminal emulator widget, and create a
480 separate MI interpreter running on a specified i/o device. In this
481 way, GDB handles line editing, history, tab completion, etc. in the
482 console all by itself, and the GUI uses the separate MI interpreter
483 for its own control and synchronization, invisible to the command
486 * The "catch syscall" command catches groups of related syscalls.
488 The "catch syscall" command now supports catching a group of related
489 syscalls using the 'group:' or 'g:' prefix.
494 skip -gfile file-glob-pattern
495 skip -function function
496 skip -rfunction regular-expression
497 A generalized form of the skip command, with new support for
498 glob-style file names and regular expressions for function names.
499 Additionally, a file spec and a function spec may now be combined.
501 maint info line-table REGEXP
502 Display the contents of GDB's internal line table data struture.
505 Run any GDB unit tests that were compiled in.
508 Start a new user interface instance running INTERP as interpreter,
509 using the TTY file for input/output.
513 ** gdb.Breakpoint objects have a new attribute "pending", which
514 indicates whether the breakpoint is pending.
515 ** Three new breakpoint-related events have been added:
516 gdb.breakpoint_created, gdb.breakpoint_modified, and
517 gdb.breakpoint_deleted.
520 Signal ("set") the given MS-Windows event object. This is used in
521 conjunction with the Windows JIT debugging (AeDebug) support, where
522 the OS suspends a crashing process until a debugger can attach to
523 it. Resuming the crashing process, in order to debug it, is done by
526 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
527 was added in GDBserver, including JIT compiling fast tracepoint's
528 conditional expression bytecode into native code.
530 * Support for various remote target protocols and ROM monitors has
533 target m32rsdi Remote M32R debugging over SDI
534 target mips MIPS remote debugging protocol
535 target pmon PMON ROM monitor
536 target ddb NEC's DDB variant of PMON for Vr4300
537 target rockhopper NEC RockHopper variant of PMON
538 target lsi LSI variant of PMO
540 * Support for tracepoints and fast tracepoints on powerpc-linux,
541 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
542 including JIT compiling fast tracepoint's conditional expression
543 bytecode into native code.
545 * MI async record =record-started now includes the method and format used for
546 recording. For example:
548 =record-started,thread-group="i1",method="btrace",format="bts"
550 * MI async record =thread-selected now includes the frame field. For example:
552 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
556 Andes NDS32 nds32*-*-elf
558 *** Changes in GDB 7.11
560 * GDB now supports debugging kernel-based threads on FreeBSD.
562 * Per-inferior thread numbers
564 Thread numbers are now per inferior instead of global. If you're
565 debugging multiple inferiors, GDB displays thread IDs using a
566 qualified INF_NUM.THR_NUM form. For example:
570 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
571 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
572 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
573 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
575 As consequence, thread numbers as visible in the $_thread
576 convenience variable and in Python's InferiorThread.num attribute
577 are no longer unique between inferiors.
579 GDB now maintains a second thread ID per thread, referred to as the
580 global thread ID, which is the new equivalent of thread numbers in
581 previous releases. See also $_gthread below.
583 For backwards compatibility, MI's thread IDs always refer to global
586 * Commands that accept thread IDs now accept the qualified
587 INF_NUM.THR_NUM form as well. For example:
590 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
593 * In commands that accept a list of thread IDs, you can now refer to
594 all threads of an inferior using a star wildcard. GDB accepts
595 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
596 refer to all threads of the current inferior. For example, "info
599 * You can use "info threads -gid" to display the global thread ID of
602 * The new convenience variable $_gthread holds the global number of
605 * The new convenience variable $_inferior holds the number of the
608 * GDB now displays the ID and name of the thread that hit a breakpoint
609 or received a signal, if your program is multi-threaded. For
612 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
613 Thread 1 "main" received signal SIGINT, Interrupt.
615 * Record btrace now supports non-stop mode.
617 * Support for tracepoints on aarch64-linux was added in GDBserver.
619 * The 'record instruction-history' command now indicates speculative execution
620 when using the Intel Processor Trace recording format.
622 * GDB now allows users to specify explicit locations, bypassing
623 the linespec parser. This feature is also available to GDB/MI
626 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
627 GDB now is able to debug both AArch64 applications and ARM applications
630 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
631 including JIT compiling fast tracepoint's conditional expression bytecode
634 * GDB now supports displaced stepping on AArch64 GNU/Linux.
636 * "info threads", "info inferiors", "info display", "info checkpoints"
637 and "maint info program-spaces" now list the corresponding items in
638 ascending ID order, for consistency with all other "info" commands.
640 * In Ada, the overloads selection menu has been enhanced to display the
641 parameter types and the return types for the matching overloaded subprograms.
645 maint set target-non-stop (on|off|auto)
646 maint show target-non-stop
647 Control whether GDB targets always operate in non-stop mode even if
648 "set non-stop" is "off". The default is "auto", meaning non-stop
649 mode is enabled if supported by the target.
651 maint set bfd-sharing
652 maint show bfd-sharing
653 Control the reuse of bfd objects.
657 Control display of debugging info regarding bfd caching.
661 Control display of debugging info regarding FreeBSD threads.
663 set remote multiprocess-extensions-packet
664 show remote multiprocess-extensions-packet
665 Set/show the use of the remote protocol multiprocess extensions.
667 set remote thread-events
668 show remote thread-events
669 Set/show the use of thread create/exit events.
671 set ada print-signatures on|off
672 show ada print-signatures"
673 Control whether parameter types and return types are displayed in overloads
674 selection menus. It is activaled (@code{on}) by default.
678 Controls the maximum size of memory, in bytes, that GDB will
679 allocate for value contents. Prevents incorrect programs from
680 causing GDB to allocate overly large buffers. Default is 64k.
682 * The "disassemble" command accepts a new modifier: /s.
683 It prints mixed source+disassembly like /m with two differences:
684 - disassembled instructions are now printed in program order, and
685 - and source for all relevant files is now printed.
686 The "/m" option is now considered deprecated: its "source-centric"
687 output hasn't proved useful in practice.
689 * The "record instruction-history" command accepts a new modifier: /s.
690 It behaves exactly like /m and prints mixed source+disassembly.
692 * The "set scheduler-locking" command supports a new mode "replay".
693 It behaves like "off" in record mode and like "on" in replay mode.
695 * Support for various ROM monitors has been removed:
697 target dbug dBUG ROM monitor for Motorola ColdFire
698 target picobug Motorola picobug monitor
699 target dink32 DINK32 ROM monitor for PowerPC
700 target m32r Renesas M32R/D ROM monitor
701 target mon2000 mon2000 ROM monitor
702 target ppcbug PPCBUG ROM monitor for PowerPC
704 * Support for reading/writing memory and extracting values on architectures
705 whose memory is addressable in units of any integral multiple of 8 bits.
708 Allows to break when an Ada exception is handled.
713 Indicates that an exec system call was executed.
715 exec-events feature in qSupported
716 The qSupported packet allows GDB to request support for exec
717 events using the new 'gdbfeature' exec-event, and the qSupported
718 response can contain the corresponding 'stubfeature'. Set and
719 show commands can be used to display whether these features are enabled.
722 Equivalent to interrupting with the ^C character, but works in
725 thread created stop reason (T05 create:...)
726 Indicates that the thread was just created and is stopped at entry.
728 thread exit stop reply (w exitcode;tid)
729 Indicates that the thread has terminated.
732 Enables/disables thread create and exit event reporting. For
733 example, this is used in non-stop mode when GDB stops a set of
734 threads and synchronously waits for the their corresponding stop
735 replies. Without exit events, if one of the threads exits, GDB
736 would hang forever not knowing that it should no longer expect a
737 stop for that same thread.
740 Indicates that there are no resumed threads left in the target (all
741 threads are stopped). The remote stub reports support for this stop
742 reply to GDB's qSupported query.
745 Enables/disables catching syscalls from the inferior process.
746 The remote stub reports support for this packet to GDB's qSupported query.
748 syscall_entry stop reason
749 Indicates that a syscall was just called.
751 syscall_return stop reason
752 Indicates that a syscall just returned.
754 * Extended-remote exec events
756 ** GDB now has support for exec events on extended-remote Linux targets.
757 For such targets with Linux kernels 2.5.46 and later, this enables
758 follow-exec-mode and exec catchpoints.
760 set remote exec-event-feature-packet
761 show remote exec-event-feature-packet
762 Set/show the use of the remote exec event feature.
764 * Thread names in remote protocol
766 The reply to qXfer:threads:read may now include a name attribute for each
769 * Target remote mode fork and exec events
771 ** GDB now has support for fork and exec events on target remote mode
772 Linux targets. For such targets with Linux kernels 2.5.46 and later,
773 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
774 fork and exec catchpoints.
776 * Remote syscall events
778 ** GDB now has support for catch syscall on remote Linux targets,
779 currently enabled on x86/x86_64 architectures.
781 set remote catch-syscall-packet
782 show remote catch-syscall-packet
783 Set/show the use of the remote catch syscall feature.
787 ** The -var-set-format command now accepts the zero-hexadecimal
788 format. It outputs data in hexadecimal format with zero-padding on the
793 ** gdb.InferiorThread objects have a new attribute "global_num",
794 which refers to the thread's global thread ID. The existing
795 "num" attribute now refers to the thread's per-inferior number.
796 See "Per-inferior thread numbers" above.
797 ** gdb.InferiorThread objects have a new attribute "inferior", which
798 is the Inferior object the thread belongs to.
800 *** Changes in GDB 7.10
802 * Support for process record-replay and reverse debugging on aarch64*-linux*
803 targets has been added. GDB now supports recording of A64 instruction set
804 including advance SIMD instructions.
806 * Support for Sun's version of the "stabs" debug file format has been removed.
808 * GDB now honors the content of the file /proc/PID/coredump_filter
809 (PID is the process ID) on GNU/Linux systems. This file can be used
810 to specify the types of memory mappings that will be included in a
811 corefile. For more information, please refer to the manual page of
812 "core(5)". GDB also has a new command: "set use-coredump-filter
813 on|off". It allows to set whether GDB will read the content of the
814 /proc/PID/coredump_filter file when generating a corefile.
816 * The "info os" command on GNU/Linux can now display information on
818 "info os cpus" Listing of all cpus/cores on the system
820 * GDB has two new commands: "set serial parity odd|even|none" and
821 "show serial parity". These allows to set or show parity for the
824 * The "info source" command now displays the producer string if it was
825 present in the debug info. This typically includes the compiler version
826 and may include things like its command line arguments.
828 * The "info dll", an alias of the "info sharedlibrary" command,
829 is now available on all platforms.
831 * Directory names supplied to the "set sysroot" commands may be
832 prefixed with "target:" to tell GDB to access shared libraries from
833 the target system, be it local or remote. This replaces the prefix
834 "remote:". The default sysroot has been changed from "" to
835 "target:". "remote:" is automatically converted to "target:" for
836 backward compatibility.
838 * The system root specified by "set sysroot" will be prepended to the
839 filename of the main executable (if reported to GDB as absolute by
840 the operating system) when starting processes remotely, and when
841 attaching to already-running local or remote processes.
843 * GDB now supports automatic location and retrieval of executable
844 files from remote targets. Remote debugging can now be initiated
845 using only a "target remote" or "target extended-remote" command
846 (no "set sysroot" or "file" commands are required). See "New remote
849 * The "dump" command now supports verilog hex format.
851 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
853 * On GNU/Linux, GDB and gdbserver are now able to access executable
854 and shared library files without a "set sysroot" command when
855 attaching to processes running in different mount namespaces from
856 the debugger. This makes it possible to attach to processes in
857 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
858 See "New remote packets" below.
860 * The "tui reg" command now provides completion for all of the
861 available register groups, including target specific groups.
863 * The HISTSIZE environment variable is no longer read when determining
864 the size of GDB's command history. GDB now instead reads the dedicated
865 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
866 disables truncation of command history. Non-numeric values of GDBHISTSIZE
871 ** Memory ports can now be unbuffered.
875 ** gdb.Objfile objects have a new attribute "username",
876 which is the name of the objfile as specified by the user,
877 without, for example, resolving symlinks.
878 ** You can now write frame unwinders in Python.
879 ** gdb.Type objects have a new method "optimized_out",
880 returning optimized out gdb.Value instance of this type.
881 ** gdb.Value objects have new methods "reference_value" and
882 "const_value" which return a reference to the value and a
883 "const" version of the value respectively.
887 maint print symbol-cache
888 Print the contents of the symbol cache.
890 maint print symbol-cache-statistics
891 Print statistics of symbol cache usage.
893 maint flush-symbol-cache
894 Flush the contents of the symbol cache.
898 Start branch trace recording using Branch Trace Store (BTS) format.
901 Evaluate expression by using the compiler and print result.
905 Explicit commands for enabling and disabling tui mode.
908 set mpx bound on i386 and amd64
909 Support for bound table investigation on Intel MPX enabled applications.
913 Start branch trace recording using Intel Processor Trace format.
916 Print information about branch tracing internals.
918 maint btrace packet-history
919 Print the raw branch tracing data.
921 maint btrace clear-packet-history
922 Discard the stored raw branch tracing data.
925 Discard all branch tracing data. It will be fetched and processed
926 anew by the next "record" command.
931 Renamed from "set debug dwarf2-die".
933 Renamed from "show debug dwarf2-die".
936 Renamed from "set debug dwarf2-read".
937 show debug dwarf-read
938 Renamed from "show debug dwarf2-read".
940 maint set dwarf always-disassemble
941 Renamed from "maint set dwarf2 always-disassemble".
942 maint show dwarf always-disassemble
943 Renamed from "maint show dwarf2 always-disassemble".
945 maint set dwarf max-cache-age
946 Renamed from "maint set dwarf2 max-cache-age".
947 maint show dwarf max-cache-age
948 Renamed from "maint show dwarf2 max-cache-age".
951 show debug dwarf-line
952 Control display of debugging info regarding DWARF line processing.
956 Set the maximum number of candidates to be considered during
957 completion. The default value is 200. This limit allows GDB
958 to avoid generating large completion lists, the computation of
959 which can cause the debugger to become temporarily unresponsive.
961 set history remove-duplicates
962 show history remove-duplicates
963 Control the removal of duplicate history entries.
965 maint set symbol-cache-size
966 maint show symbol-cache-size
967 Control the size of the symbol cache.
969 set|show record btrace bts buffer-size
970 Set and show the size of the ring buffer used for branch tracing in
972 The obtained size may differ from the requested size. Use "info
973 record" to see the obtained buffer size.
975 set debug linux-namespaces
976 show debug linux-namespaces
977 Control display of debugging info regarding Linux namespaces.
979 set|show record btrace pt buffer-size
980 Set and show the size of the ring buffer used for branch tracing in
981 Intel Processor Trace format.
982 The obtained size may differ from the requested size. Use "info
983 record" to see the obtained buffer size.
985 maint set|show btrace pt skip-pad
986 Set and show whether PAD packets are skipped when computing the
989 * The command 'thread apply all' can now support new option '-ascending'
990 to call its specified command for all threads in ascending order.
992 * Python/Guile scripting
994 ** GDB now supports auto-loading of Python/Guile scripts contained in the
995 special section named `.debug_gdb_scripts'.
999 qXfer:btrace-conf:read
1000 Return the branch trace configuration for the current thread.
1002 Qbtrace-conf:bts:size
1003 Set the requested ring buffer size for branch tracing in BTS format.
1006 Enable Intel Procesor Trace-based branch tracing for the current
1007 process. The remote stub reports support for this packet to GDB's
1010 Qbtrace-conf:pt:size
1011 Set the requested ring buffer size for branch tracing in Intel Processor
1015 Indicates a memory breakpoint instruction was executed, irrespective
1016 of whether it was GDB that planted the breakpoint or the breakpoint
1017 is hardcoded in the program. This is required for correct non-stop
1021 Indicates the target stopped for a hardware breakpoint. This is
1022 required for correct non-stop mode operation.
1025 Return information about files on the remote system.
1027 qXfer:exec-file:read
1028 Return the full absolute name of the file that was executed to
1029 create a process running on the remote system.
1032 Select the filesystem on which vFile: operations with filename
1033 arguments will operate. This is required for GDB to be able to
1034 access files on remote targets where the remote stub does not
1035 share a common filesystem with the inferior(s).
1038 Indicates that a fork system call was executed.
1041 Indicates that a vfork system call was executed.
1043 vforkdone stop reason
1044 Indicates that a vfork child of the specified process has executed
1045 an exec or exit, allowing the vfork parent to resume execution.
1047 fork-events and vfork-events features in qSupported
1048 The qSupported packet allows GDB to request support for fork and
1049 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1050 and the qSupported response can contain the corresponding
1051 'stubfeatures'. Set and show commands can be used to display
1052 whether these features are enabled.
1054 * Extended-remote fork events
1056 ** GDB now has support for fork events on extended-remote Linux
1057 targets. For targets with Linux kernels 2.5.60 and later, this
1058 enables follow-fork-mode and detach-on-fork for both fork and
1059 vfork, as well as fork and vfork catchpoints.
1061 * The info record command now shows the recording format and the
1062 branch tracing configuration for the current thread when using
1063 the btrace record target.
1064 For the BTS format, it shows the ring buffer size.
1066 * GDB now has support for DTrace USDT (Userland Static Defined
1067 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1069 * GDB now supports access to vector registers on S/390 GNU/Linux
1072 * Removed command line options
1074 -xdb HP-UX XDB compatibility mode.
1076 * Removed targets and native configurations
1078 HP/PA running HP-UX hppa*-*-hpux*
1079 Itanium running HP-UX ia64-*-hpux*
1081 * New configure options
1084 This configure option allows the user to build GDB with support for
1085 Intel Processor Trace (default: auto). This requires libipt.
1087 --with-libipt-prefix=PATH
1088 Specify the path to the version of libipt that GDB should use.
1089 $PATH/include should contain the intel-pt.h header and
1090 $PATH/lib should contain the libipt.so library.
1092 *** Changes in GDB 7.9.1
1096 ** Xmethods can now specify a result type.
1098 *** Changes in GDB 7.9
1100 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1104 ** You can now access frame registers from Python scripts.
1105 ** New attribute 'producer' for gdb.Symtab objects.
1106 ** gdb.Objfile objects have a new attribute "progspace",
1107 which is the gdb.Progspace object of the containing program space.
1108 ** gdb.Objfile objects have a new attribute "owner".
1109 ** gdb.Objfile objects have a new attribute "build_id",
1110 which is the build ID generated when the file was built.
1111 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1112 ** A new event "gdb.clear_objfiles" has been added, triggered when
1113 selecting a new file to debug.
1114 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1115 ** New function gdb.lookup_objfile.
1117 New events which are triggered when GDB modifies the state of the
1120 ** gdb.events.inferior_call_pre: Function call is about to be made.
1121 ** gdb.events.inferior_call_post: Function call has just been made.
1122 ** gdb.events.memory_changed: A memory location has been altered.
1123 ** gdb.events.register_changed: A register has been altered.
1125 * New Python-based convenience functions:
1127 ** $_caller_is(name [, number_of_frames])
1128 ** $_caller_matches(regexp [, number_of_frames])
1129 ** $_any_caller_is(name [, number_of_frames])
1130 ** $_any_caller_matches(regexp [, number_of_frames])
1132 * GDB now supports the compilation and injection of source code into
1133 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1134 to compile the source code to object code, and if successful, inject
1135 and execute that code within the current context of the inferior.
1136 Currently the C language is supported. The commands used to
1137 interface with this new feature are:
1139 compile code [-raw|-r] [--] [source code]
1140 compile file [-raw|-r] filename
1144 demangle [-l language] [--] name
1145 Demangle "name" in the specified language, or the current language
1146 if elided. This command is renamed from the "maint demangle" command.
1147 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1148 as "maint demangler-warning".
1150 queue-signal signal-name-or-number
1151 Queue a signal to be delivered to the thread when it is resumed.
1153 add-auto-load-scripts-directory directory
1154 Add entries to the list of directories from which to load auto-loaded
1157 maint print user-registers
1158 List all currently available "user" registers.
1160 compile code [-r|-raw] [--] [source code]
1161 Compile, inject, and execute in the inferior the executable object
1162 code produced by compiling the provided source code.
1164 compile file [-r|-raw] filename
1165 Compile and inject into the inferior the executable object code
1166 produced by compiling the source code stored in the filename
1169 * On resume, GDB now always passes the signal the program had stopped
1170 for to the thread the signal was sent to, even if the user changed
1171 threads before resuming. Previously GDB would often (but not
1172 always) deliver the signal to the thread that happens to be current
1175 * Conversely, the "signal" command now consistently delivers the
1176 requested signal to the current thread. GDB now asks for
1177 confirmation if the program had stopped for a signal and the user
1178 switched threads meanwhile.
1180 * "breakpoint always-inserted" modes "off" and "auto" merged.
1182 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1183 won't remove breakpoints from the target until all threads stop,
1184 even in non-stop mode. The "auto" mode has been removed, and "off"
1185 is now the default mode.
1189 set debug symbol-lookup
1190 show debug symbol-lookup
1191 Control display of debugging info regarding symbol lookup.
1195 ** The -list-thread-groups command outputs an exit-code field for
1196 inferiors that have exited.
1200 MIPS SDE mips*-sde*-elf*
1204 Support for these obsolete configurations has been removed.
1206 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1207 SGI Irix-5.x mips-*-irix5*
1208 SGI Irix-6.x mips-*-irix6*
1209 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1210 VAX running Ultrix vax-*-ultrix*
1212 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1213 and "assf"), have been removed. Use the "sharedlibrary" command, or
1214 its alias "share", instead.
1216 *** Changes in GDB 7.8
1218 * New command line options
1221 This is an alias for the --data-directory option.
1223 * GDB supports printing and modifying of variable length automatic arrays
1224 as specified in ISO C99.
1226 * The ARM simulator now supports instruction level tracing
1227 with or without disassembly.
1231 GDB now has support for scripting using Guile. Whether this is
1232 available is determined at configure time.
1233 Guile version 2.0 or greater is required.
1234 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1236 * New commands (for set/show, see "New options" below)
1240 Invoke CODE by passing it to the Guile interpreter.
1244 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1246 info auto-load guile-scripts [regexp]
1247 Print the list of automatically loaded Guile scripts.
1249 * The source command is now capable of sourcing Guile scripts.
1250 This feature is dependent on the debugger being built with Guile support.
1254 set print symbol-loading (off|brief|full)
1255 show print symbol-loading
1256 Control whether to print informational messages when loading symbol
1257 information for a file. The default is "full", but when debugging
1258 programs with large numbers of shared libraries the amount of output
1259 becomes less useful.
1261 set guile print-stack (none|message|full)
1262 show guile print-stack
1263 Show a stack trace when an error is encountered in a Guile script.
1265 set auto-load guile-scripts (on|off)
1266 show auto-load guile-scripts
1267 Control auto-loading of Guile script files.
1269 maint ada set ignore-descriptive-types (on|off)
1270 maint ada show ignore-descriptive-types
1271 Control whether the debugger should ignore descriptive types in Ada
1272 programs. The default is not to ignore the descriptive types. See
1273 the user manual for more details on descriptive types and the intended
1274 usage of this option.
1276 set auto-connect-native-target
1278 Control whether GDB is allowed to automatically connect to the
1279 native target for the run, attach, etc. commands when not connected
1280 to any target yet. See also "target native" below.
1282 set record btrace replay-memory-access (read-only|read-write)
1283 show record btrace replay-memory-access
1284 Control what memory accesses are allowed during replay.
1286 maint set target-async (on|off)
1287 maint show target-async
1288 This controls whether GDB targets operate in synchronous or
1289 asynchronous mode. Normally the default is asynchronous, if it is
1290 available; but this can be changed to more easily debug problems
1291 occurring only in synchronous mode.
1293 set mi-async (on|off)
1295 Control whether MI asynchronous mode is preferred. This supersedes
1296 "set target-async" of previous GDB versions.
1298 * "set target-async" is deprecated as a CLI option and is now an alias
1299 for "set mi-async" (only puts MI into async mode).
1301 * Background execution commands (e.g., "c&", "s&", etc.) are now
1302 possible ``out of the box'' if the target supports them. Previously
1303 the user would need to explicitly enable the possibility with the
1304 "set target-async on" command.
1306 * New features in the GDB remote stub, GDBserver
1308 ** New option --debug-format=option1[,option2,...] allows one to add
1309 additional text to each output. At present only timestamps
1310 are supported: --debug-format=timestamps.
1311 Timestamps can also be turned on with the
1312 "monitor set debug-format timestamps" command from GDB.
1314 * The 'record instruction-history' command now starts counting instructions
1315 at one. This also affects the instruction ranges reported by the
1316 'record function-call-history' command when given the /i modifier.
1318 * The command 'record function-call-history' supports a new modifier '/c' to
1319 indent the function names based on their call stack depth.
1320 The fields for the '/i' and '/l' modifier have been reordered.
1321 The source line range is now prefixed with 'at'.
1322 The instruction range is now prefixed with 'inst'.
1323 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1324 "record instruction-history" and "list" commands.
1326 * The ranges given as arguments to the 'record function-call-history' and
1327 'record instruction-history' commands are now inclusive.
1329 * The btrace record target now supports the 'record goto' command.
1330 For locations inside the execution trace, the back trace is computed
1331 based on the information stored in the execution trace.
1333 * The btrace record target supports limited reverse execution and replay.
1334 The target does not record data and therefore does not allow reading
1335 memory or registers.
1337 * The "catch syscall" command now works on s390*-linux* targets.
1339 * The "compare-sections" command is no longer specific to target
1340 remote. It now works with all targets.
1342 * All native targets are now consistently called "native".
1343 Consequently, the "target child", "target GNU", "target djgpp",
1344 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1345 commands have been replaced with "target native". The QNX/NTO port
1346 leaves the "procfs" target in place and adds a "native" target for
1347 consistency with other ports. The impact on users should be minimal
1348 as these commands previously either throwed an error, or were
1349 no-ops. The target's name is visible in the output of the following
1350 commands: "help target", "info target", "info files", "maint print
1353 * The "target native" command now connects to the native target. This
1354 can be used to launch native programs even when "set
1355 auto-connect-native-target" is set to off.
1357 * GDB now supports access to Intel MPX registers on GNU/Linux.
1359 * Support for Intel AVX-512 registers on GNU/Linux.
1360 Support displaying and modifying Intel AVX-512 registers
1361 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1363 * New remote packets
1365 qXfer:btrace:read's annex
1366 The qXfer:btrace:read packet supports a new annex 'delta' to read
1367 branch trace incrementally.
1371 ** Valid Python operations on gdb.Value objects representing
1372 structs/classes invoke the corresponding overloaded operators if
1374 ** New `Xmethods' feature in the Python API. Xmethods are
1375 additional methods or replacements for existing methods of a C++
1376 class. This feature is useful for those cases where a method
1377 defined in C++ source code could be inlined or optimized out by
1378 the compiler, making it unavailable to GDB.
1381 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1383 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1384 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1385 its alias "share", instead.
1387 * The commands "set remotebaud" and "show remotebaud" are no longer
1388 supported. Use "set serial baud" and "show serial baud" (respectively)
1393 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1394 target-async". The latter is left as a deprecated alias of the
1395 former for backward compatibility. If the target supports it,
1396 CLI background execution commands are now always possible by
1397 default, independently of whether the frontend stated a
1398 preference for asynchronous execution with "-gdb-set mi-async".
1399 Previously "-gdb-set target-async off" affected both MI execution
1400 commands and CLI execution commands.
1402 *** Changes in GDB 7.7
1404 * Improved support for process record-replay and reverse debugging on
1405 arm*-linux* targets. Support for thumb32 and syscall instruction
1406 recording has been added.
1408 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1410 * GDB now supports Fission DWP file format version 2.
1411 http://gcc.gnu.org/wiki/DebugFission
1413 * New convenience function "$_isvoid", to check whether an expression
1414 is void. A void expression is an expression where the type of the
1415 result is "void". For example, some convenience variables may be
1416 "void" when evaluated (e.g., "$_exitcode" before the execution of
1417 the program being debugged; or an undefined convenience variable).
1418 Another example, when calling a function whose return type is
1421 * The "maintenance print objfiles" command now takes an optional regexp.
1423 * The "catch syscall" command now works on arm*-linux* targets.
1425 * GDB now consistently shows "<not saved>" when printing values of
1426 registers the debug info indicates have not been saved in the frame
1427 and there's nowhere to retrieve them from
1428 (callee-saved/call-clobbered registers):
1433 (gdb) info registers rax
1436 Before, the former would print "<optimized out>", and the latter
1437 "*value not available*".
1439 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1444 ** Frame filters and frame decorators have been added.
1445 ** Temporary breakpoints are now supported.
1446 ** Line tables representation has been added.
1447 ** New attribute 'parent_type' for gdb.Field objects.
1448 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1449 ** New attribute 'name' for gdb.Type objects.
1453 Nios II ELF nios2*-*-elf
1454 Nios II GNU/Linux nios2*-*-linux
1455 Texas Instruments MSP430 msp430*-*-elf
1457 * Removed native configurations
1459 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1460 been removed. ELF variants of these configurations are kept supported.
1462 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1463 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1464 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1465 i[34567]86-*-openbsd3.[0-3]
1466 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1467 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1468 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1472 Like "catch throw", but catches a re-thrown exception.
1473 maint check-psymtabs
1474 Renamed from old "maint check-symtabs".
1476 Perform consistency checks on symtabs.
1477 maint expand-symtabs
1478 Expand symtabs matching an optional regexp.
1481 Display the details of GDB configure-time options.
1483 maint set|show per-command
1484 maint set|show per-command space
1485 maint set|show per-command time
1486 maint set|show per-command symtab
1487 Enable display of per-command gdb resource usage.
1489 remove-symbol-file FILENAME
1490 remove-symbol-file -a ADDRESS
1491 Remove a symbol file added via add-symbol-file. The file to remove
1492 can be identified by its filename or by an address that lies within
1493 the boundaries of this symbol file in memory.
1496 info exceptions REGEXP
1497 Display the list of Ada exceptions defined in the program being
1498 debugged. If provided, only the exceptions whose names match REGEXP
1503 set debug symfile off|on
1505 Control display of debugging info regarding reading symbol files and
1506 symbol tables within those files
1508 set print raw frame-arguments
1509 show print raw frame-arguments
1510 Set/show whether to print frame arguments in raw mode,
1511 disregarding any defined pretty-printers.
1513 set remote trace-status-packet
1514 show remote trace-status-packet
1515 Set/show the use of remote protocol qTStatus packet.
1519 Control display of debugging messages related to Nios II targets.
1523 Control whether target-assisted range stepping is enabled.
1525 set startup-with-shell
1526 show startup-with-shell
1527 Specifies whether Unix child processes are started via a shell or
1532 Use the target memory cache for accesses to the code segment. This
1533 improves performance of remote debugging (particularly disassembly).
1535 * You can now use a literal value 'unlimited' for options that
1536 interpret 0 or -1 as meaning "unlimited". E.g., "set
1537 trace-buffer-size unlimited" is now an alias for "set
1538 trace-buffer-size -1" and "set height unlimited" is now an alias for
1541 * The "set debug symtab-create" debugging option of GDB has been changed to
1542 accept a verbosity level. 0 means "off", 1 provides basic debugging
1543 output, and values of 2 or greater provides more verbose output.
1545 * New command-line options
1547 Display the details of GDB configure-time options.
1549 * The command 'tsave' can now support new option '-ctf' to save trace
1550 buffer in Common Trace Format.
1552 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1555 * GDB now implements the the C++ 'typeid' operator.
1557 * The new convenience variable $_exception holds the exception being
1558 thrown or caught at an exception-related catchpoint.
1560 * The exception-related catchpoints, like "catch throw", now accept a
1561 regular expression which can be used to filter exceptions by type.
1563 * The new convenience variable $_exitsignal is automatically set to
1564 the terminating signal number when the program being debugged dies
1565 due to an uncaught signal.
1569 ** All MI commands now accept an optional "--language" option.
1570 Support for this feature can be verified by using the "-list-features"
1571 command, which should contain "language-option".
1573 ** The new command -info-gdb-mi-command allows the user to determine
1574 whether a GDB/MI command is supported or not.
1576 ** The "^error" result record returned when trying to execute an undefined
1577 GDB/MI command now provides a variable named "code" whose content is the
1578 "undefined-command" error code. Support for this feature can be verified
1579 by using the "-list-features" command, which should contain
1580 "undefined-command-error-code".
1582 ** The -trace-save MI command can optionally save trace buffer in Common
1585 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1587 ** The command -data-list-register-values now accepts an optional
1588 "--skip-unavailable" option. When used, only the available registers
1591 ** The new command -trace-frame-collected dumps collected variables,
1592 computed expressions, tvars, memory and registers in a traceframe.
1594 ** The commands -stack-list-locals, -stack-list-arguments and
1595 -stack-list-variables now accept an option "--skip-unavailable".
1596 When used, only the available locals or arguments are displayed.
1598 ** The -exec-run command now accepts an optional "--start" option.
1599 When used, the command follows the same semantics as the "start"
1600 command, stopping the program's execution at the start of its
1601 main subprogram. Support for this feature can be verified using
1602 the "-list-features" command, which should contain
1603 "exec-run-start-option".
1605 ** The new commands -catch-assert and -catch-exceptions insert
1606 catchpoints stopping the program when Ada exceptions are raised.
1608 ** The new command -info-ada-exceptions provides the equivalent of
1609 the new "info exceptions" command.
1611 * New system-wide configuration scripts
1612 A GDB installation now provides scripts suitable for use as system-wide
1613 configuration scripts for the following systems:
1617 * GDB now supports target-assigned range stepping with remote targets.
1618 This improves the performance of stepping source lines by reducing
1619 the number of control packets from/to GDB. See "New remote packets"
1622 * GDB now understands the element 'tvar' in the XML traceframe info.
1623 It has the id of the collected trace state variables.
1625 * On S/390 targets that provide the transactional-execution feature,
1626 the program interruption transaction diagnostic block (TDB) is now
1627 represented as a number of additional "registers" in GDB.
1629 * New remote packets
1633 The vCont packet supports a new 'r' action, that tells the remote
1634 stub to step through an address range itself, without GDB
1635 involvemement at each single-step.
1637 qXfer:libraries-svr4:read's annex
1638 The previously unused annex of the qXfer:libraries-svr4:read packet
1639 is now used to support passing an argument list. The remote stub
1640 reports support for this argument list to GDB's qSupported query.
1641 The defined arguments are "start" and "prev", used to reduce work
1642 necessary for library list updating, resulting in significant
1645 * New features in the GDB remote stub, GDBserver
1647 ** GDBserver now supports target-assisted range stepping. Currently
1648 enabled on x86/x86_64 GNU/Linux targets.
1650 ** GDBserver now adds element 'tvar' in the XML in the reply to
1651 'qXfer:traceframe-info:read'. It has the id of the collected
1652 trace state variables.
1654 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1657 * New 'z' formatter for printing and examining memory, this displays the
1658 value as hexadecimal zero padded on the left to the size of the type.
1660 * GDB can now use Windows x64 unwinding data.
1662 * The "set remotebaud" command has been replaced by "set serial baud".
1663 Similarly, "show remotebaud" has been replaced by "show serial baud".
1664 The "set remotebaud" and "show remotebaud" commands are still available
1665 to provide backward compatibility with older versions of GDB.
1667 *** Changes in GDB 7.6
1669 * Target record has been renamed to record-full.
1670 Record/replay is now enabled with the "record full" command.
1671 This also affects settings that are associated with full record/replay
1672 that have been moved from "set/show record" to "set/show record full":
1674 set|show record full insn-number-max
1675 set|show record full stop-at-limit
1676 set|show record full memory-query
1678 * A new record target "record-btrace" has been added. The new target
1679 uses hardware support to record the control-flow of a process. It
1680 does not support replaying the execution, but it implements the
1681 below new commands for investigating the recorded execution log.
1682 This new recording method can be enabled using:
1686 The "record-btrace" target is only available on Intel Atom processors
1687 and requires a Linux kernel 2.6.32 or later.
1689 * Two new commands have been added for record/replay to give information
1690 about the recorded execution without having to replay the execution.
1691 The commands are only supported by "record btrace".
1693 record instruction-history prints the execution history at
1694 instruction granularity
1696 record function-call-history prints the execution history at
1697 function granularity
1699 * New native configurations
1701 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1702 FreeBSD/powerpc powerpc*-*-freebsd
1703 x86_64/Cygwin x86_64-*-cygwin*
1704 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1708 ARM AArch64 aarch64*-*-elf
1709 ARM AArch64 GNU/Linux aarch64*-*-linux
1710 Lynx 178 PowerPC powerpc-*-lynx*178
1711 x86_64/Cygwin x86_64-*-cygwin*
1712 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1714 * If the configured location of system.gdbinit file (as given by the
1715 --with-system-gdbinit option at configure time) is in the
1716 data-directory (as specified by --with-gdb-datadir at configure
1717 time) or in one of its subdirectories, then GDB will look for the
1718 system-wide init file in the directory specified by the
1719 --data-directory command-line option.
1721 * New command line options:
1723 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1724 other initialization files, unlike -nx which disables all of them.
1726 * Removed command line options
1728 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1731 * The 'ptype' and 'whatis' commands now accept an argument to control
1734 * 'info proc' now works on some core files.
1738 ** Vectors can be created with gdb.Type.vector.
1740 ** Python's atexit.register now works in GDB.
1742 ** Types can be pretty-printed via a Python API.
1744 ** Python 3 is now supported (in addition to Python 2.4 or later)
1746 ** New class gdb.Architecture exposes GDB's internal representation
1747 of architecture in the Python API.
1749 ** New method Frame.architecture returns the gdb.Architecture object
1750 corresponding to the frame's architecture.
1752 * New Python-based convenience functions:
1754 ** $_memeq(buf1, buf2, length)
1755 ** $_streq(str1, str2)
1757 ** $_regex(str, regex)
1759 * The 'cd' command now defaults to using '~' (the home directory) if not
1762 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1763 default for GCC since November 2000.
1765 * The command 'forward-search' can now be abbreviated as 'fo'.
1767 * The command 'info tracepoints' can now display 'installed on target'
1768 or 'not installed on target' for each non-pending location of tracepoint.
1770 * New configure options
1772 --enable-libmcheck/--disable-libmcheck
1773 By default, development versions are built with -lmcheck on hosts
1774 that support it, in order to help track memory corruption issues.
1775 Release versions, on the other hand, are built without -lmcheck
1776 by default. The --enable-libmcheck/--disable-libmcheck configure
1777 options allow the user to override that default.
1778 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1779 This configure option allows the user to build GDB with
1780 libbabeltrace using which GDB can read Common Trace Format data.
1782 * New commands (for set/show, see "New options" below)
1785 Catch signals. This is similar to "handle", but allows commands and
1786 conditions to be attached.
1789 List the BFDs known to GDB.
1791 python-interactive [command]
1793 Start a Python interactive prompt, or evaluate the optional command
1794 and print the result of expressions.
1797 "py" is a new alias for "python".
1799 enable type-printer [name]...
1800 disable type-printer [name]...
1801 Enable or disable type printers.
1805 ** For the Renesas Super-H architecture, the "regs" command has been removed
1806 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1811 set print type methods (on|off)
1812 show print type methods
1813 Control whether method declarations are displayed by "ptype".
1814 The default is to show them.
1816 set print type typedefs (on|off)
1817 show print type typedefs
1818 Control whether typedef definitions are displayed by "ptype".
1819 The default is to show them.
1821 set filename-display basename|relative|absolute
1822 show filename-display
1823 Control the way in which filenames is displayed.
1824 The default is "relative", which preserves previous behavior.
1826 set trace-buffer-size
1827 show trace-buffer-size
1828 Request target to change the size of trace buffer.
1830 set remote trace-buffer-size-packet auto|on|off
1831 show remote trace-buffer-size-packet
1832 Control the use of the remote protocol `QTBuffer:size' packet.
1836 Control display of debugging messages related to ARM AArch64.
1839 set debug coff-pe-read
1840 show debug coff-pe-read
1841 Control display of debugging messages related to reading of COFF/PE
1846 Control display of debugging messages related to Mach-O symbols
1849 set debug notification
1850 show debug notification
1851 Control display of debugging info for async remote notification.
1855 ** Command parameter changes are now notified using new async record
1856 "=cmd-param-changed".
1857 ** Trace frame changes caused by command "tfind" are now notified using
1858 new async record "=traceframe-changed".
1859 ** The creation, deletion and modification of trace state variables
1860 are now notified using new async records "=tsv-created",
1861 "=tsv-deleted" and "=tsv-modified".
1862 ** The start and stop of process record are now notified using new
1863 async record "=record-started" and "=record-stopped".
1864 ** Memory changes are now notified using new async record
1866 ** The data-disassemble command response will include a "fullname" field
1867 containing the absolute file name when source has been requested.
1868 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1869 command, to allow pattern filling of memory areas.
1870 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1871 library load/unload events.
1872 ** The response to breakpoint commands and breakpoint async records
1873 includes an "installed" field containing a boolean state about each
1874 non-pending tracepoint location is whether installed on target or not.
1875 ** Output of the "-trace-status" command includes a "trace-file" field
1876 containing the name of the trace file being examined. This field is
1877 optional, and only present when examining a trace file.
1878 ** The "fullname" field is now always present along with the "file" field,
1879 even if the file cannot be found by GDB.
1881 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1882 You must have the LZMA library available when configuring GDB for this
1883 feature to be enabled. For more information, see:
1884 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1886 * New remote packets
1889 Set the size of trace buffer. The remote stub reports support for this
1890 packet to gdb's qSupported query.
1893 Enable Branch Trace Store (BTS)-based branch tracing for the current
1894 thread. The remote stub reports support for this packet to gdb's
1898 Disable branch tracing for the current thread. The remote stub reports
1899 support for this packet to gdb's qSupported query.
1902 Read the traced branches for the current thread. The remote stub
1903 reports support for this packet to gdb's qSupported query.
1905 *** Changes in GDB 7.5
1907 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1908 for more x32 ABI info.
1910 * GDB now supports access to MIPS DSP registers on Linux targets.
1912 * GDB now supports debugging microMIPS binaries.
1914 * The "info os" command on GNU/Linux can now display information on
1915 several new classes of objects managed by the operating system:
1916 "info os procgroups" lists process groups
1917 "info os files" lists file descriptors
1918 "info os sockets" lists internet-domain sockets
1919 "info os shm" lists shared-memory regions
1920 "info os semaphores" lists semaphores
1921 "info os msg" lists message queues
1922 "info os modules" lists loaded kernel modules
1924 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1925 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1926 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1927 options and inspect the probe arguments using the new $_probe_arg family
1928 of convenience variables. You can obtain more information about SystemTap
1929 in <http://sourceware.org/systemtap/>.
1931 * GDB now supports reversible debugging on ARM, it allows you to
1932 debug basic ARM and THUMB instructions, and provides
1933 record/replay support.
1935 * The option "symbol-reloading" has been deleted as it is no longer used.
1939 ** GDB commands implemented in Python can now be put in command class
1942 ** The "maint set python print-stack on|off" is now deleted.
1944 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1945 apply "flag enum"-style pretty-printing to any enum.
1947 ** gdb.lookup_symbol can now work when there is no current frame.
1949 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1950 the source at which the symbol was defined.
1952 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1953 method 'value'. The former indicates whether the symbol needs a
1954 frame in order to compute its value, and the latter computes the
1957 ** A new method 'referenced_value' on gdb.Value objects which can
1958 dereference pointer as well as C++ reference values.
1960 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1961 which return the global and static blocks (as gdb.Block objects),
1962 of the underlying symbol table, respectively.
1964 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1965 object associated with a PC value.
1967 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1968 of the address range occupied by code for the current source line.
1970 * Go language support.
1971 GDB now supports debugging programs written in the Go programming
1974 * GDBserver now supports stdio connections.
1975 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1977 * The binary "gdbtui" can no longer be built or installed.
1978 Use "gdb -tui" instead.
1980 * GDB will now print "flag" enums specially. A flag enum is one where
1981 all the enumerator values have no bits in common when pairwise
1982 "and"ed. When printing a value whose type is a flag enum, GDB will
1983 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1984 (gdb) print (enum E) 3
1987 * The filename part of a linespec will now match trailing components
1988 of a source file name. For example, "break gcc/expr.c:1000" will
1989 now set a breakpoint in build/gcc/expr.c, but not
1990 build/libcpp/expr.c.
1992 * The "info proc" and "generate-core-file" commands will now also
1993 work on remote targets connected to GDBserver on Linux.
1995 * The command "info catch" has been removed. It has been disabled
1996 since December 2007.
1998 * The "catch exception" and "catch assert" commands now accept
1999 a condition at the end of the command, much like the "break"
2000 command does. For instance:
2002 (gdb) catch exception Constraint_Error if Barrier = True
2004 Previously, it was possible to add a condition to such catchpoints,
2005 but it had to be done as a second step, after the catchpoint had been
2006 created, using the "condition" command.
2008 * The "info static-tracepoint-marker" command will now also work on
2009 native Linux targets with in-process agent.
2011 * GDB can now set breakpoints on inlined functions.
2013 * The .gdb_index section has been updated to include symbols for
2014 inlined functions. GDB will ignore older .gdb_index sections by
2015 default, which could cause symbol files to be loaded more slowly
2016 until their .gdb_index sections can be recreated. The new command
2017 "set use-deprecated-index-sections on" will cause GDB to use any older
2018 .gdb_index sections it finds. This will restore performance, but the
2019 ability to set breakpoints on inlined functions will be lost in symbol
2020 files with older .gdb_index sections.
2022 The .gdb_index section has also been updated to record more information
2023 about each symbol. This speeds up the "info variables", "info functions"
2024 and "info types" commands when used with programs having the .gdb_index
2025 section, as well as speeding up debugging with shared libraries using
2026 the .gdb_index section.
2028 * Ada support for GDB/MI Variable Objects has been added.
2030 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2035 ** New command -info-os is the MI equivalent of "info os".
2037 ** Output logs ("set logging" and related) now include MI output.
2041 ** "set use-deprecated-index-sections on|off"
2042 "show use-deprecated-index-sections on|off"
2043 Controls the use of deprecated .gdb_index sections.
2045 ** "catch load" and "catch unload" can be used to stop when a shared
2046 library is loaded or unloaded, respectively.
2048 ** "enable count" can be used to auto-disable a breakpoint after
2051 ** "info vtbl" can be used to show the virtual method tables for
2052 C++ and Java objects.
2054 ** "explore" and its sub commands "explore value" and "explore type"
2055 can be used to recursively explore values and types of
2056 expressions. These commands are available only if GDB is
2057 configured with '--with-python'.
2059 ** "info auto-load" shows status of all kinds of auto-loaded files,
2060 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2061 sequences of commands files, "info auto-load python-scripts"
2062 shows status of auto-loading Python script files,
2063 "info auto-load local-gdbinit" shows status of loading init file
2064 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2065 status of inferior specific thread debugging shared library loading.
2067 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2068 and "show auto-load-scripts" commands have been deprecated, use their
2069 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2070 and "show auto-load python-scripts" counterparts instead.
2072 ** "dprintf location,format,args..." creates a dynamic printf, which
2073 is basically a breakpoint that does a printf and immediately
2074 resumes your program's execution, so it is like a printf that you
2075 can insert dynamically at runtime instead of at compiletime.
2077 ** "set print symbol"
2079 Controls whether GDB attempts to display the symbol, if any,
2080 corresponding to addresses it prints. This defaults to "on", but
2081 you can set it to "off" to restore GDB's previous behavior.
2083 * Deprecated commands
2085 ** For the Renesas Super-H architecture, the "regs" command has been
2086 deprecated, and "info all-registers" should be used instead.
2090 Renesas RL78 rl78-*-elf
2091 HP OpenVMS ia64 ia64-hp-openvms*
2093 * GDBserver supports evaluation of breakpoint conditions. When
2094 support is advertised by GDBserver, GDB may be told to send the
2095 breakpoint conditions in bytecode form to GDBserver. GDBserver
2096 will only report the breakpoint trigger to GDB when its condition
2101 set mips compression
2102 show mips compression
2103 Select the compressed ISA encoding used in functions that have no symbol
2104 information available. The encoding can be set to either of:
2107 and is updated automatically from ELF file flags if available.
2109 set breakpoint condition-evaluation
2110 show breakpoint condition-evaluation
2111 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2112 GDBserver ("target"). Default option "auto" chooses the most efficient
2114 This option can improve debugger efficiency depending on the speed of the
2118 Disable auto-loading globally.
2121 Show auto-loading setting of all kinds of auto-loaded files.
2123 set auto-load gdb-scripts on|off
2124 show auto-load gdb-scripts
2125 Control auto-loading of GDB canned sequences of commands files.
2127 set auto-load python-scripts on|off
2128 show auto-load python-scripts
2129 Control auto-loading of Python script files.
2131 set auto-load local-gdbinit on|off
2132 show auto-load local-gdbinit
2133 Control loading of init file (.gdbinit) from current directory.
2135 set auto-load libthread-db on|off
2136 show auto-load libthread-db
2137 Control auto-loading of inferior specific thread debugging shared library.
2139 set auto-load scripts-directory <dir1>[:<dir2>...]
2140 show auto-load scripts-directory
2141 Set a list of directories from which to load auto-loaded scripts.
2142 Automatically loaded Python scripts and GDB scripts are located in one
2143 of the directories listed by this option.
2144 The delimiter (':' above) may differ according to the host platform.
2146 set auto-load safe-path <dir1>[:<dir2>...]
2147 show auto-load safe-path
2148 Set a list of directories from which it is safe to auto-load files.
2149 The delimiter (':' above) may differ according to the host platform.
2151 set debug auto-load on|off
2152 show debug auto-load
2153 Control display of debugging info for auto-loading the files above.
2155 set dprintf-style gdb|call|agent
2157 Control the way in which a dynamic printf is performed; "gdb"
2158 requests a GDB printf command, while "call" causes dprintf to call a
2159 function in the inferior. "agent" requests that the target agent
2160 (such as GDBserver) do the printing.
2162 set dprintf-function <expr>
2163 show dprintf-function
2164 set dprintf-channel <expr>
2165 show dprintf-channel
2166 Set the function and optional first argument to the call when using
2167 the "call" style of dynamic printf.
2169 set disconnected-dprintf on|off
2170 show disconnected-dprintf
2171 Control whether agent-style dynamic printfs continue to be in effect
2172 after GDB disconnects.
2174 * New configure options
2176 --with-auto-load-dir
2177 Configure default value for the 'set auto-load scripts-directory'
2178 setting above. It defaults to '$debugdir:$datadir/auto-load',
2179 $debugdir representing global debugging info directories (available
2180 via 'show debug-file-directory') and $datadir representing GDB's data
2181 directory (available via 'show data-directory').
2183 --with-auto-load-safe-path
2184 Configure default value for the 'set auto-load safe-path' setting
2185 above. It defaults to the --with-auto-load-dir setting.
2187 --without-auto-load-safe-path
2188 Set 'set auto-load safe-path' to '/', effectively disabling this
2191 * New remote packets
2193 z0/z1 conditional breakpoints extension
2195 The z0/z1 breakpoint insertion packets have been extended to carry
2196 a list of conditional expressions over to the remote stub depending on the
2197 condition evaluation mode. The use of this extension can be controlled
2198 via the "set remote conditional-breakpoints-packet" command.
2202 Specify the signals which the remote stub may pass to the debugged
2203 program without GDB involvement.
2205 * New command line options
2207 --init-command=FILE, -ix Like --command, -x but execute it
2208 before loading inferior.
2209 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2210 execute it before loading inferior.
2212 *** Changes in GDB 7.4
2214 * GDB now handles ambiguous linespecs more consistently; the existing
2215 FILE:LINE support has been expanded to other types of linespecs. A
2216 breakpoint will now be set on all matching locations in all
2217 inferiors, and locations will be added or removed according to
2220 * GDB now allows you to skip uninteresting functions and files when
2221 stepping with the "skip function" and "skip file" commands.
2223 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2224 and "show remote hardware-watchpoint-length-limit". These allows to
2225 set or show the maximum length limit (in bytes) of a remote
2226 target hardware watchpoint.
2228 This allows e.g. to use "unlimited" hardware watchpoints with the
2229 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2230 watchpoints are slower than real hardware watchpoints but are
2231 significantly faster than gdb software watchpoints.
2235 ** The register_pretty_printer function in module gdb.printing now takes
2236 an optional `replace' argument. If True, the new printer replaces any
2239 ** The "maint set python print-stack on|off" command has been
2240 deprecated and will be deleted in GDB 7.5.
2241 A new command: "set python print-stack none|full|message" has
2242 replaced it. Additionally, the default for "print-stack" is
2243 now "message", which just prints the error message without
2246 ** A prompt substitution hook (prompt_hook) is now available to the
2249 ** A new Python module, gdb.prompt has been added to the GDB Python
2250 modules library. This module provides functionality for
2251 escape sequences in prompts (used by set/show
2252 extended-prompt). These escape sequences are replaced by their
2253 corresponding value.
2255 ** Python commands and convenience-functions located in
2256 'data-directory'/python/gdb/command and
2257 'data-directory'/python/gdb/function are now automatically loaded
2260 ** Blocks now provide four new attributes. global_block and
2261 static_block will return the global and static blocks
2262 respectively. is_static and is_global are boolean attributes
2263 that indicate if the block is one of those two types.
2265 ** Symbols now provide the "type" attribute, the type of the symbol.
2267 ** The "gdb.breakpoint" function has been deprecated in favor of
2270 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2271 of a function. This class is based on the "finish" command
2272 available in the CLI.
2274 ** Type objects for struct and union types now allow access to
2275 the fields using standard Python dictionary (mapping) methods.
2276 For example, "some_type['myfield']" now works, as does
2277 "some_type.items()".
2279 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2282 ** A new function, "deep_items" has been added to the gdb.types
2283 module in the GDB Python modules library. This function returns
2284 an iterator over the fields of a struct or union type. Unlike
2285 the standard Python "iteritems" method, it will recursively traverse
2286 any anonymous fields.
2290 ** "*stopped" events can report several new "reason"s, such as
2293 ** Breakpoint changes are now notified using new async records, like
2294 "=breakpoint-modified".
2296 ** New command -ada-task-info.
2298 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2299 $sdir specifies the default system locations of shared libraries.
2300 $pdir specifies the directory where the libpthread used by the application
2303 GDB no longer looks in $sdir and $pdir after it has searched the directories
2304 mentioned in libthread-db-search-path. If you want to search those
2305 directories, they must be specified in libthread-db-search-path.
2306 The default value of libthread-db-search-path on GNU/Linux and Solaris
2307 systems is now "$sdir:$pdir".
2309 $pdir is not supported by gdbserver, it is currently ignored.
2310 $sdir is supported by gdbserver.
2312 * New configure option --with-iconv-bin.
2313 When using the internationalization support like the one in the GNU C
2314 library, GDB will invoke the "iconv" program to get a list of supported
2315 character sets. If this program lives in a non-standard location, one can
2316 use this option to specify where to find it.
2318 * When natively debugging programs on PowerPC BookE processors running
2319 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2320 watchpoints, which specify a mask in addition to an address to watch.
2321 The mask specifies that some bits of an address (the bits which are
2322 reset in the mask) should be ignored when matching the address accessed
2323 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2324 section in the user manual for more details.
2326 * The new option --once causes GDBserver to stop listening for connections once
2327 the first connection is made. The listening port used by GDBserver will
2328 become available after that.
2330 * New commands "info macros" and "alias" have been added.
2332 * New function parameters suffix @entry specifies value of function parameter
2333 at the time the function got called. Entry values are available only since
2339 "!" is now an alias of the "shell" command.
2340 Note that no space is needed between "!" and SHELL COMMAND.
2344 watch EXPRESSION mask MASK_VALUE
2345 The watch command now supports the mask argument which allows creation
2346 of masked watchpoints, if the current architecture supports this feature.
2348 info auto-load-scripts [REGEXP]
2349 This command was formerly named "maintenance print section-scripts".
2350 It is now generally useful and is no longer a maintenance-only command.
2352 info macro [-all] [--] MACRO
2353 The info macro command has new options `-all' and `--'. The first for
2354 printing all definitions of a macro. The second for explicitly specifying
2355 the end of arguments and the beginning of the macro name in case the macro
2356 name starts with a hyphen.
2358 collect[/s] EXPRESSIONS
2359 The tracepoint collect command now takes an optional modifier "/s"
2360 that directs it to dereference pointer-to-character types and
2361 collect the bytes of memory up to a zero byte. The behavior is
2362 similar to what you see when you use the regular print command on a
2363 string. An optional integer following the "/s" sets a bound on the
2364 number of bytes that will be collected.
2367 The trace start command now interprets any supplied arguments as a
2368 note to be recorded with the trace run, with an effect similar to
2369 setting the variable trace-notes.
2372 The trace stop command now interprets any arguments as a note to be
2373 mentioned along with the tstatus report that the trace was stopped
2374 with a command. The effect is similar to setting the variable
2377 * Tracepoints can now be enabled and disabled at any time after a trace
2378 experiment has been started using the standard "enable" and "disable"
2379 commands. It is now possible to start a trace experiment with no enabled
2380 tracepoints; GDB will display a warning, but will allow the experiment to
2381 begin, assuming that tracepoints will be enabled as needed while the trace
2384 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2385 locations with 4-byte instructions, when they were previously
2386 limited to locations with instructions of 5 bytes or longer.
2390 set debug dwarf2-read
2391 show debug dwarf2-read
2392 Turns on or off display of debugging messages related to reading
2393 DWARF debug info. The default is off.
2395 set debug symtab-create
2396 show debug symtab-create
2397 Turns on or off display of debugging messages related to symbol table
2398 creation. The default is off.
2401 show extended-prompt
2402 Set the GDB prompt, and allow escape sequences to be inserted to
2403 display miscellaneous information (see 'help set extended-prompt'
2404 for the list of sequences). This prompt (and any information
2405 accessed through the escape sequences) is updated every time the
2406 prompt is displayed.
2408 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2409 show print entry-values
2410 Set printing of frame argument values at function entry. In some cases
2411 GDB can determine the value of function argument which was passed by the
2412 function caller, even if the value was modified inside the called function.
2414 set debug entry-values
2415 show debug entry-values
2416 Control display of debugging info for determining frame argument values at
2417 function entry and virtual tail call frames.
2419 set basenames-may-differ
2420 show basenames-may-differ
2421 Set whether a source file may have multiple base names.
2422 (A "base name" is the name of a file with the directory part removed.
2423 Example: The base name of "/home/user/hello.c" is "hello.c".)
2424 If set, GDB will canonicalize file names (e.g., expand symlinks)
2425 before comparing them. Canonicalization is an expensive operation,
2426 but it allows the same file be known by more than one base name.
2427 If not set (the default), all source files are assumed to have just
2428 one base name, and gdb will do file name comparisons more efficiently.
2434 Set a user name and notes for the current and any future trace runs.
2435 This is useful for long-running and/or disconnected traces, to
2436 inform others (or yourself) as to who is running the trace, supply
2437 contact information, or otherwise explain what is going on.
2439 set trace-stop-notes
2440 show trace-stop-notes
2441 Set a note attached to the trace run, that is displayed when the
2442 trace has been stopped by a tstop command. This is useful for
2443 instance as an explanation, if you are stopping a trace run that was
2444 started by someone else.
2446 * New remote packets
2450 Dynamically enable a tracepoint in a started trace experiment.
2454 Dynamically disable a tracepoint in a started trace experiment.
2458 Set the user and notes of the trace run.
2462 Query the current status of a tracepoint.
2466 Query the minimum length of instruction at which a fast tracepoint may
2469 * Dcache size (number of lines) and line-size are now runtime-configurable
2470 via "set dcache line" and "set dcache line-size" commands.
2474 Texas Instruments TMS320C6x tic6x-*-*
2478 Renesas RL78 rl78-*-elf
2480 *** Changes in GDB 7.3.1
2482 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2484 *** Changes in GDB 7.3
2486 * GDB has a new command: "thread find [REGEXP]".
2487 It finds the thread id whose name, target id, or thread extra info
2488 matches the given regular expression.
2490 * The "catch syscall" command now works on mips*-linux* targets.
2492 * The -data-disassemble MI command now supports modes 2 and 3 for
2493 dumping the instruction opcodes.
2495 * New command line options
2497 -data-directory DIR Specify DIR as the "data-directory".
2498 This is mostly for testing purposes.
2500 * The "maint set python auto-load on|off" command has been renamed to
2501 "set auto-load-scripts on|off".
2503 * GDB has a new command: "set directories".
2504 It is like the "dir" command except that it replaces the
2505 source path list instead of augmenting it.
2507 * GDB now understands thread names.
2509 On GNU/Linux, "info threads" will display the thread name as set by
2510 prctl or pthread_setname_np.
2512 There is also a new command, "thread name", which can be used to
2513 assign a name internally for GDB to display.
2516 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2517 has been integrated into GDB.
2521 ** The function gdb.Write now accepts an optional keyword 'stream'.
2522 This keyword, when provided, will direct the output to either
2523 stdout, stderr, or GDB's logging output.
2525 ** Parameters can now be be sub-classed in Python, and in particular
2526 you may implement the get_set_doc and get_show_doc functions.
2527 This improves how Parameter set/show documentation is processed
2528 and allows for more dynamic content.
2530 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2531 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2532 have an is_valid method.
2534 ** Breakpoints can now be sub-classed in Python, and in particular
2535 you may implement a 'stop' function that is executed each time
2536 the inferior reaches that breakpoint.
2538 ** New function gdb.lookup_global_symbol looks up a global symbol.
2540 ** GDB values in Python are now callable if the value represents a
2541 function. For example, if 'some_value' represents a function that
2542 takes two integer parameters and returns a value, you can call
2543 that function like so:
2545 result = some_value (10,20)
2547 ** Module gdb.types has been added.
2548 It contains a collection of utilities for working with gdb.Types objects:
2549 get_basic_type, has_field, make_enum_dict.
2551 ** Module gdb.printing has been added.
2552 It contains utilities for writing and registering pretty-printers.
2553 New classes: PrettyPrinter, SubPrettyPrinter,
2554 RegexpCollectionPrettyPrinter.
2555 New function: register_pretty_printer.
2557 ** New commands "info pretty-printers", "enable pretty-printer" and
2558 "disable pretty-printer" have been added.
2560 ** gdb.parameter("directories") is now available.
2562 ** New function gdb.newest_frame returns the newest frame in the
2565 ** The gdb.InferiorThread class has a new "name" attribute. This
2566 holds the thread's name.
2568 ** Python Support for Inferior events.
2569 Python scripts can add observers to be notified of events
2570 occurring in the process being debugged.
2571 The following events are currently supported:
2572 - gdb.events.cont Continue event.
2573 - gdb.events.exited Inferior exited event.
2574 - gdb.events.stop Signal received, and Breakpoint hit events.
2578 ** GDB now puts template parameters in scope when debugging in an
2579 instantiation. For example, if you have:
2581 template<int X> int func (void) { return X; }
2583 then if you step into func<5>, "print X" will show "5". This
2584 feature requires proper debuginfo support from the compiler; it
2585 was added to GCC 4.5.
2587 ** The motion commands "next", "finish", "until", and "advance" now
2588 work better when exceptions are thrown. In particular, GDB will
2589 no longer lose control of the inferior; instead, the GDB will
2590 stop the inferior at the point at which the exception is caught.
2591 This functionality requires a change in the exception handling
2592 code that was introduced in GCC 4.5.
2594 * GDB now follows GCC's rules on accessing volatile objects when
2595 reading or writing target state during expression evaluation.
2596 One notable difference to prior behavior is that "print x = 0"
2597 no longer generates a read of x; the value of the assignment is
2598 now always taken directly from the value being assigned.
2600 * GDB now has some support for using labels in the program's source in
2601 linespecs. For instance, you can use "advance label" to continue
2602 execution to a label.
2604 * GDB now has support for reading and writing a new .gdb_index
2605 section. This section holds a fast index of DWARF debugging
2606 information and can be used to greatly speed up GDB startup and
2607 operation. See the documentation for `save gdb-index' for details.
2609 * The "watch" command now accepts an optional "-location" argument.
2610 When used, this causes GDB to watch the memory referred to by the
2611 expression. Such a watchpoint is never deleted due to it going out
2614 * GDB now supports thread debugging of core dumps on GNU/Linux.
2616 GDB now activates thread debugging using the libthread_db library
2617 when debugging GNU/Linux core dumps, similarly to when debugging
2618 live processes. As a result, when debugging a core dump file, GDB
2619 is now able to display pthread_t ids of threads. For example, "info
2620 threads" shows the same output as when debugging the process when it
2621 was live. In earlier releases, you'd see something like this:
2624 * 1 LWP 6780 main () at main.c:10
2626 While now you see this:
2629 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2631 It is also now possible to inspect TLS variables when debugging core
2634 When debugging a core dump generated on a machine other than the one
2635 used to run GDB, you may need to point GDB at the correct
2636 libthread_db library with the "set libthread-db-search-path"
2637 command. See the user manual for more details on this command.
2639 * When natively debugging programs on PowerPC BookE processors running
2640 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2641 which stop execution of the inferior whenever it executes an instruction
2642 at any address within the specified range. See the "PowerPC Embedded"
2643 section in the user manual for more details.
2645 * New features in the GDB remote stub, GDBserver
2647 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2648 and i686 LynxOS (version 5.x).
2650 ** GDBserver is now supported on Blackfin Linux.
2652 * New native configurations
2654 ia64 HP-UX ia64-*-hpux*
2658 Analog Devices, Inc. Blackfin Processor bfin-*
2660 * Ada task switching is now supported on sparc-elf targets when
2661 debugging a program using the Ravenscar Profile. For more information,
2662 see the "Tasking Support when using the Ravenscar Profile" section
2663 in the GDB user manual.
2665 * Guile support was removed.
2667 * New features in the GNU simulator
2669 ** The --map-info flag lists all known core mappings.
2671 ** CFI flashes may be simulated via the "cfi" device.
2673 *** Changes in GDB 7.2
2675 * Shared library support for remote targets by default
2677 When GDB is configured for a generic, non-OS specific target, like
2678 for example, --target=arm-eabi or one of the many *-*-elf targets,
2679 GDB now queries remote stubs for loaded shared libraries using the
2680 `qXfer:libraries:read' packet. Previously, shared library support
2681 was always disabled for such configurations.
2685 ** Argument Dependent Lookup (ADL)
2687 In C++ ADL lookup directs function search to the namespaces of its
2688 arguments even if the namespace has not been imported.
2698 Here the compiler will search for `foo' in the namespace of 'b'
2699 and find A::foo. GDB now supports this. This construct is commonly
2700 used in the Standard Template Library for operators.
2702 ** Improved User Defined Operator Support
2704 In addition to member operators, GDB now supports lookup of operators
2705 defined in a namespace and imported with a `using' directive, operators
2706 defined in the global scope, operators imported implicitly from an
2707 anonymous namespace, and the ADL operators mentioned in the previous
2709 GDB now also supports proper overload resolution for all the previously
2710 mentioned flavors of operators.
2712 ** static const class members
2714 Printing of static const class members that are initialized in the
2715 class definition has been fixed.
2717 * Windows Thread Information Block access.
2719 On Windows targets, GDB now supports displaying the Windows Thread
2720 Information Block (TIB) structure. This structure is visible either
2721 by using the new command `info w32 thread-information-block' or, by
2722 dereferencing the new convenience variable named `$_tlb', a
2723 thread-specific pointer to the TIB. This feature is also supported
2724 when remote debugging using GDBserver.
2726 * Static tracepoints
2728 Static tracepoints are calls in the user program into a tracing
2729 library. One such library is a port of the LTTng kernel tracer to
2730 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2731 When debugging with GDBserver, GDB now supports combining the GDB
2732 tracepoint machinery with such libraries. For example: the user can
2733 use GDB to probe a static tracepoint marker (a call from the user
2734 program into the tracing library) with the new "strace" command (see
2735 "New commands" below). This creates a "static tracepoint" in the
2736 breakpoint list, that can be manipulated with the same feature set
2737 as fast and regular tracepoints. E.g., collect registers, local and
2738 global variables, collect trace state variables, and define
2739 tracepoint conditions. In addition, the user can collect extra
2740 static tracepoint marker specific data, by collecting the new
2741 $_sdata internal variable. When analyzing the trace buffer, you can
2742 inspect $_sdata like any other variable available to GDB. For more
2743 information, see the "Tracepoints" chapter in GDB user manual. New
2744 remote packets have been defined to support static tracepoints, see
2745 the "New remote packets" section below.
2747 * Better reconstruction of tracepoints after disconnected tracing
2749 GDB will attempt to download the original source form of tracepoint
2750 definitions when starting a trace run, and then will upload these
2751 upon reconnection to the target, resulting in a more accurate
2752 reconstruction of the tracepoints that are in use on the target.
2756 You can now exercise direct control over the ways that GDB can
2757 affect your program. For instance, you can disallow the setting of
2758 breakpoints, so that the program can run continuously (assuming
2759 non-stop mode). In addition, the "observer" variable is available
2760 to switch all of the different controls; in observer mode, GDB
2761 cannot affect the target's behavior at all, which is useful for
2762 tasks like diagnosing live systems in the field.
2764 * The new convenience variable $_thread holds the number of the
2767 * New remote packets
2771 Return the address of the Windows Thread Information Block of a given thread.
2775 In response to several of the tracepoint packets, the target may now
2776 also respond with a number of intermediate `qRelocInsn' request
2777 packets before the final result packet, to have GDB handle
2778 relocating an instruction to execute at a different address. This
2779 is particularly useful for stubs that support fast tracepoints. GDB
2780 reports support for this feature in the qSupported packet.
2784 List static tracepoint markers in the target program.
2788 List static tracepoint markers at a given address in the target
2791 qXfer:statictrace:read
2793 Read the static trace data collected (by a `collect $_sdata'
2794 tracepoint action). The remote stub reports support for this packet
2795 to gdb's qSupported query.
2799 Send the current settings of GDB's permission flags.
2803 Send part of the source (textual) form of a tracepoint definition,
2804 which includes location, conditional, and action list.
2806 * The source command now accepts a -s option to force searching for the
2807 script in the source search path even if the script name specifies
2810 * New features in the GDB remote stub, GDBserver
2812 - GDBserver now support tracepoints (including fast tracepoints, and
2813 static tracepoints). The feature is currently supported by the
2814 i386-linux and amd64-linux builds. See the "Tracepoints support
2815 in gdbserver" section in the manual for more information.
2817 GDBserver JIT compiles the tracepoint's conditional agent
2818 expression bytecode into native code whenever possible for low
2819 overhead dynamic tracepoints conditionals. For such tracepoints,
2820 an expression that examines program state is evaluated when the
2821 tracepoint is reached, in order to determine whether to capture
2822 trace data. If the condition is simple and false, processing the
2823 tracepoint finishes very quickly and no data is gathered.
2825 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2826 for static tracepoints support.
2828 - GDBserver now supports x86_64 Windows 64-bit debugging.
2830 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2831 it understands register description.
2833 * The --batch flag now disables pagination and queries.
2835 * X86 general purpose registers
2837 GDB now supports reading/writing byte, word and double-word x86
2838 general purpose registers directly. This means you can use, say,
2839 $ah or $ax to refer, respectively, to the byte register AH and
2840 16-bit word register AX that are actually portions of the 32-bit
2841 register EAX or 64-bit register RAX.
2843 * The `commands' command now accepts a range of breakpoints to modify.
2844 A plain `commands' following a command that creates multiple
2845 breakpoints affects all the breakpoints set by that command. This
2846 applies to breakpoints set by `rbreak', and also applies when a
2847 single `break' command creates multiple breakpoints (e.g.,
2848 breakpoints on overloaded c++ functions).
2850 * The `rbreak' command now accepts a filename specification as part of
2851 its argument, limiting the functions selected by the regex to those
2852 in the specified file.
2854 * Support for remote debugging Windows and SymbianOS shared libraries
2855 from Unix hosts has been improved. Non Windows GDB builds now can
2856 understand target reported file names that follow MS-DOS based file
2857 system semantics, such as file names that include drive letters and
2858 use the backslash character as directory separator. This makes it
2859 possible to transparently use the "set sysroot" and "set
2860 solib-search-path" on Unix hosts to point as host copies of the
2861 target's shared libraries. See the new command "set
2862 target-file-system-kind" described below, and the "Commands to
2863 specify files" section in the user manual for more information.
2867 eval template, expressions...
2868 Convert the values of one or more expressions under the control
2869 of the string template to a command line, and call it.
2871 set target-file-system-kind unix|dos-based|auto
2872 show target-file-system-kind
2873 Set or show the assumed file system kind for target reported file
2876 save breakpoints <filename>
2877 Save all current breakpoint definitions to a file suitable for use
2878 in a later debugging session. To read the saved breakpoint
2879 definitions, use the `source' command.
2881 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2884 info static-tracepoint-markers
2885 Display information about static tracepoint markers in the target.
2887 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2888 Define a static tracepoint by probing a marker at the given
2889 function, line, address, or marker ID.
2893 Enable and disable observer mode.
2895 set may-write-registers on|off
2896 set may-write-memory on|off
2897 set may-insert-breakpoints on|off
2898 set may-insert-tracepoints on|off
2899 set may-insert-fast-tracepoints on|off
2900 set may-interrupt on|off
2901 Set individual permissions for GDB effects on the target. Note that
2902 some of these settings can have undesirable or surprising
2903 consequences, particularly when changed in the middle of a session.
2904 For instance, disabling the writing of memory can prevent
2905 breakpoints from being inserted, cause single-stepping to fail, or
2906 even crash your program, if you disable after breakpoints have been
2907 inserted. However, GDB should not crash.
2909 set record memory-query on|off
2910 show record memory-query
2911 Control whether to stop the inferior if memory changes caused
2912 by an instruction cannot be recorded.
2917 The disassemble command now supports "start,+length" form of two arguments.
2921 ** GDB now provides a new directory location, called the python directory,
2922 where Python scripts written for GDB can be installed. The location
2923 of that directory is <data-directory>/python, where <data-directory>
2924 is the GDB data directory. For more details, see section `Scripting
2925 GDB using Python' in the manual.
2927 ** The GDB Python API now has access to breakpoints, symbols, symbol
2928 tables, program spaces, inferiors, threads and frame's code blocks.
2929 Additionally, GDB Parameters can now be created from the API, and
2930 manipulated via set/show in the CLI.
2932 ** New functions gdb.target_charset, gdb.target_wide_charset,
2933 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2935 ** New exception gdb.GdbError.
2937 ** Pretty-printers are now also looked up in the current program space.
2939 ** Pretty-printers can now be individually enabled and disabled.
2941 ** GDB now looks for names of Python scripts to auto-load in a
2942 special section named `.debug_gdb_scripts', in addition to looking
2943 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2945 * Tracepoint actions were unified with breakpoint commands. In particular,
2946 there are no longer differences in "info break" output for breakpoints and
2947 tracepoints and the "commands" command can be used for both tracepoints and
2948 regular breakpoints.
2952 ARM Symbian arm*-*-symbianelf*
2954 * D language support.
2955 GDB now supports debugging programs written in the D programming
2958 * GDB now supports the extended ptrace interface for PowerPC which is
2959 available since Linux kernel version 2.6.34. This automatically enables
2960 any hardware breakpoints and additional hardware watchpoints available in
2961 the processor. The old ptrace interface exposes just one hardware
2962 watchpoint and no hardware breakpoints.
2964 * GDB is now able to use the Data Value Compare (DVC) register available on
2965 embedded PowerPC processors to implement in hardware simple watchpoint
2966 conditions of the form:
2968 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2970 This works in native GDB running on Linux kernels with the extended ptrace
2971 interface mentioned above.
2973 *** Changes in GDB 7.1
2977 ** Namespace Support
2979 GDB now supports importing of namespaces in C++. This enables the
2980 user to inspect variables from imported namespaces. Support for
2981 namepace aliasing has also been added. So, if a namespace is
2982 aliased in the current scope (e.g. namepace C=A; ) the user can
2983 print variables using the alias (e.g. (gdb) print C::x).
2987 All known bugs relating to the printing of virtual base class were
2988 fixed. It is now possible to call overloaded static methods using a
2993 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2994 and reinterpret_cast<> are now handled by the C++ expression parser.
2998 Xilinx MicroBlaze microblaze-*-*
3003 Xilinx MicroBlaze microblaze
3006 * Multi-program debugging.
3008 GDB now has support for multi-program (a.k.a. multi-executable or
3009 multi-exec) debugging. This allows for debugging multiple inferiors
3010 simultaneously each running a different program under the same GDB
3011 session. See "Debugging Multiple Inferiors and Programs" in the
3012 manual for more information. This implied some user visible changes
3013 in the multi-inferior support. For example, "info inferiors" now
3014 lists inferiors that are not running yet or that have exited
3015 already. See also "New commands" and "New options" below.
3017 * New tracing features
3019 GDB's tracepoint facility now includes several new features:
3021 ** Trace state variables
3023 GDB tracepoints now include support for trace state variables, which
3024 are variables managed by the target agent during a tracing
3025 experiment. They are useful for tracepoints that trigger each
3026 other, so for instance one tracepoint can count hits in a variable,
3027 and then a second tracepoint has a condition that is true when the
3028 count reaches a particular value. Trace state variables share the
3029 $-syntax of GDB convenience variables, and can appear in both
3030 tracepoint actions and condition expressions. Use the "tvariable"
3031 command to create, and "info tvariables" to view; see "Trace State
3032 Variables" in the manual for more detail.
3036 GDB now includes an option for defining fast tracepoints, which
3037 targets may implement more efficiently, such as by installing a jump
3038 into the target agent rather than a trap instruction. The resulting
3039 speedup can be by two orders of magnitude or more, although the
3040 tradeoff is that some program locations on some target architectures
3041 might not allow fast tracepoint installation, for instance if the
3042 instruction to be replaced is shorter than the jump. To request a
3043 fast tracepoint, use the "ftrace" command, with syntax identical to
3044 the regular trace command.
3046 ** Disconnected tracing
3048 It is now possible to detach GDB from the target while it is running
3049 a trace experiment, then reconnect later to see how the experiment
3050 is going. In addition, a new variable disconnected-tracing lets you
3051 tell the target agent whether to continue running a trace if the
3052 connection is lost unexpectedly.
3056 GDB now has the ability to save the trace buffer into a file, and
3057 then use that file as a target, similarly to you can do with
3058 corefiles. You can select trace frames, print data that was
3059 collected in them, and use tstatus to display the state of the
3060 tracing run at the moment that it was saved. To create a trace
3061 file, use "tsave <filename>", and to use it, do "target tfile
3064 ** Circular trace buffer
3066 You can ask the target agent to handle the trace buffer as a
3067 circular buffer, discarding the oldest trace frames to make room for
3068 newer ones, by setting circular-trace-buffer to on. This feature may
3069 not be available for all target agents.
3074 The disassemble command, when invoked with two arguments, now requires
3075 the arguments to be comma-separated.
3078 The info variables command now displays variable definitions. Files
3079 which only declare a variable are not shown.
3082 The source command is now capable of sourcing Python scripts.
3083 This feature is dependent on the debugger being build with Python
3086 Related to this enhancement is also the introduction of a new command
3087 "set script-extension" (see below).
3089 * New commands (for set/show, see "New options" below)
3091 record save [<FILENAME>]
3092 Save a file (in core file format) containing the process record
3093 execution log for replay debugging at a later time.
3095 record restore <FILENAME>
3096 Restore the process record execution log that was saved at an
3097 earlier time, for replay debugging.
3099 add-inferior [-copies <N>] [-exec <FILENAME>]
3102 clone-inferior [-copies <N>] [ID]
3103 Make a new inferior ready to execute the same program another
3104 inferior has loaded.
3109 maint info program-spaces
3110 List the program spaces loaded into GDB.
3112 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3113 show remote interrupt-sequence
3114 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3115 as the sequence to the remote target in order to interrupt the execution.
3116 Ctrl-C is a default. Some system prefers BREAK which is high level of
3117 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3118 Magic SysRq g. It is BREAK signal and character 'g'.
3120 set remote interrupt-on-connect [on | off]
3121 show remote interrupt-on-connect
3122 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3123 remote target when gdb connects to it. This is needed when you debug
3126 set remotebreak [on | off]
3128 Deprecated. Use "set/show remote interrupt-sequence" instead.
3130 tvariable $NAME [ = EXP ]
3131 Create or modify a trace state variable.
3134 List trace state variables and their values.
3136 delete tvariable $NAME ...
3137 Delete one or more trace state variables.
3140 Evaluate the given expressions without collecting anything into the
3141 trace buffer. (Valid in tracepoint actions only.)
3143 ftrace FN / FILE:LINE / *ADDR
3144 Define a fast tracepoint at the given function, line, or address.
3146 * New expression syntax
3148 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3149 GDB now parses 0b101010 identically with 42.
3153 set follow-exec-mode new|same
3154 show follow-exec-mode
3155 Control whether GDB reuses the same inferior across an exec call or
3156 creates a new one. This is useful to be able to restart the old
3157 executable after the inferior having done an exec call.
3159 set default-collect EXPR, ...
3160 show default-collect
3161 Define a list of expressions to be collected at each tracepoint.
3162 This is a useful way to ensure essential items are not overlooked,
3163 such as registers or a critical global variable.
3165 set disconnected-tracing
3166 show disconnected-tracing
3167 If set to 1, the target is instructed to continue tracing if it
3168 loses its connection to GDB. If 0, the target is to stop tracing
3171 set circular-trace-buffer
3172 show circular-trace-buffer
3173 If set to on, the target is instructed to use a circular trace buffer
3174 and discard the oldest trace frames instead of stopping the trace due
3175 to a full trace buffer. If set to off, the trace stops when the buffer
3176 fills up. Some targets may not support this.
3178 set script-extension off|soft|strict
3179 show script-extension
3180 If set to "off", the debugger does not perform any script language
3181 recognition, and all sourced files are assumed to be GDB scripts.
3182 If set to "soft" (the default), files are sourced according to
3183 filename extension, falling back to GDB scripts if the first
3185 If set to "strict", files are sourced according to filename extension.
3187 set ada trust-PAD-over-XVS on|off
3188 show ada trust-PAD-over-XVS
3189 If off, activate a workaround against a bug in the debugging information
3190 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3191 the GCC sources for more information about the GNAT encoding and
3192 PAD types in particular). It is always safe to set this option to
3193 off, but this introduces a slight performance penalty. The default
3196 * Python API Improvements
3198 ** GDB provides the new class gdb.LazyString. This is useful in
3199 some pretty-printing cases. The new method gdb.Value.lazy_string
3200 provides a simple way to create objects of this type.
3202 ** The fields returned by gdb.Type.fields now have an
3203 `is_base_class' attribute.
3205 ** The new method gdb.Type.range returns the range of an array type.
3207 ** The new method gdb.parse_and_eval can be used to parse and
3208 evaluate an expression.
3210 * New remote packets
3213 Define a trace state variable.
3216 Get the current value of a trace state variable.
3219 Set desired tracing behavior upon disconnection.
3222 Set the trace buffer to be linear or circular.
3225 Get data about the tracepoints currently in use.
3229 Process record now works correctly with hardware watchpoints.
3231 Multiple bug fixes have been made to the mips-irix port, making it
3232 much more reliable. In particular:
3233 - Debugging threaded applications is now possible again. Previously,
3234 GDB would hang while starting the program, or while waiting for
3235 the program to stop at a breakpoint.
3236 - Attaching to a running process no longer hangs.
3237 - An error occurring while loading a core file has been fixed.
3238 - Changing the value of the PC register now works again. This fixes
3239 problems observed when using the "jump" command, or when calling
3240 a function from GDB, or even when assigning a new value to $pc.
3241 - With the "finish" and "return" commands, the return value for functions
3242 returning a small array is now correctly printed.
3243 - It is now possible to break on shared library code which gets executed
3244 during a shared library init phase (code executed while executing
3245 their .init section). Previously, the breakpoint would have no effect.
3246 - GDB is now able to backtrace through the signal handler for
3247 non-threaded programs.
3249 PIE (Position Independent Executable) programs debugging is now supported.
3250 This includes debugging execution of PIC (Position Independent Code) shared
3251 libraries although for that, it should be possible to run such libraries as an
3254 *** Changes in GDB 7.0
3256 * GDB now has an interface for JIT compilation. Applications that
3257 dynamically generate code can create symbol files in memory and register
3258 them with GDB. For users, the feature should work transparently, and
3259 for JIT developers, the interface is documented in the GDB manual in the
3260 "JIT Compilation Interface" chapter.
3262 * Tracepoints may now be conditional. The syntax is as for
3263 breakpoints; either an "if" clause appended to the "trace" command,
3264 or the "condition" command is available. GDB sends the condition to
3265 the target for evaluation using the same bytecode format as is used
3266 for tracepoint actions.
3268 * The disassemble command now supports: an optional /r modifier, print the
3269 raw instructions in hex as well as in symbolic form, and an optional /m
3270 modifier to print mixed source+assembly.
3272 * Process record and replay
3274 In a architecture environment that supports ``process record and
3275 replay'', ``process record and replay'' target can record a log of
3276 the process execution, and replay it with both forward and reverse
3279 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3280 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3281 set execution-direction {forward|reverse}, for targets that support
3284 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3285 feature is available with a native GDB running on kernel version
3288 * GDB now has support for multi-byte and wide character sets on the
3289 target. Strings whose character type is wchar_t, char16_t, or
3290 char32_t are now correctly printed. GDB supports wide- and unicode-
3291 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3292 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3293 `printf'. This feature requires iconv to work properly; if your
3294 system does not have a working iconv, GDB can use GNU libiconv. See
3295 the installation instructions for more information.
3297 * GDB now supports automatic retrieval of shared library files from
3298 remote targets. To use this feature, specify a system root that begins
3299 with the `remote:' prefix, either via the `set sysroot' command or via
3300 the `--with-sysroot' configure-time option.
3302 * "info sharedlibrary" now takes an optional regex of libraries to show,
3303 and it now reports if a shared library has no debugging information.
3305 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3306 now complete on file names.
3308 * When completing in expressions, gdb will attempt to limit
3309 completions to allowable structure or union fields, where appropriate.
3310 For instance, consider:
3312 # struct example { int f1; double f2; };
3313 # struct example variable;
3316 If the user types TAB at the end of this command line, the available
3317 completions will be "f1" and "f2".
3319 * Inlined functions are now supported. They show up in backtraces, and
3320 the "step", "next", and "finish" commands handle them automatically.
3322 * GDB now supports the token-splicing (##) and stringification (#)
3323 operators when expanding macros. It also supports variable-arity
3326 * GDB now supports inspecting extra signal information, exported by
3327 the new $_siginfo convenience variable. The feature is currently
3328 implemented on linux ARM, i386 and amd64.
3330 * GDB can now display the VFP floating point registers and NEON vector
3331 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3332 can provide these registers (requires Linux 2.6.30 or later). Remote
3333 and simulator targets may also provide them.
3335 * New remote packets
3338 Search memory for a sequence of bytes.
3341 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3342 operation over reliable transport links. Use of this packet is
3343 controlled by the `set remote noack-packet' command.
3346 Kill the process with the specified process ID. Use this in preference
3347 to `k' when multiprocess protocol extensions are supported.
3350 Obtains additional operating system information
3354 Read or write additional signal information.
3356 * Removed remote protocol undocumented extension
3358 An undocumented extension to the remote protocol's `S' stop reply
3359 packet that permited the stub to pass a process id was removed.
3360 Remote servers should use the `T' stop reply packet instead.
3362 * GDB now supports multiple function calling conventions according to the
3363 DWARF-2 DW_AT_calling_convention function attribute.
3365 * The SH target utilizes the aforementioned change to distinguish between gcc
3366 and Renesas calling convention. It also adds the new CLI commands
3367 `set/show sh calling-convention'.
3369 * GDB can now read compressed debug sections, as produced by GNU gold
3370 with the --compress-debug-sections=zlib flag.
3372 * 64-bit core files are now supported on AIX.
3374 * Thread switching is now supported on Tru64.
3376 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3377 which will be allocated using malloc later in program execution.
3379 * The qXfer:libraries:read remote procotol packet now allows passing a
3380 list of section offsets.
3382 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3383 conditions handling signals delivered during attach or thread creation
3384 have also been fixed.
3386 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3387 From the user's standpoint, all unqualified instances of True and False
3388 are treated as the standard definitions, regardless of context.
3390 * GDB now parses C++ symbol and type names more flexibly. For
3393 template<typename T> class C { };
3396 GDB will now correctly handle all of:
3398 ptype C<char const *>
3399 ptype C<char const*>
3400 ptype C<const char *>
3401 ptype C<const char*>
3403 * New features in the GDB remote stub, gdbserver
3405 - The "--wrapper" command-line argument tells gdbserver to use a
3406 wrapper program to launch programs for debugging.
3408 - On PowerPC and S/390 targets, it is now possible to use a single
3409 gdbserver executable to debug both 32-bit and 64-bit programs.
3410 (This requires gdbserver itself to be built as a 64-bit executable.)
3412 - gdbserver uses the new noack protocol mode for TCP connections to
3413 reduce communications latency, if also supported and enabled in GDB.
3415 - Support for the sparc64-linux-gnu target is now included in
3418 - The amd64-linux build of gdbserver now supports debugging both
3419 32-bit and 64-bit programs.
3421 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3422 now support hardware watchpoints, and will use them automatically
3427 GDB now has support for scripting using Python. Whether this is
3428 available is determined at configure time.
3430 New GDB commands can now be written in Python.
3432 * Ada tasking support
3434 Ada tasks can now be inspected in GDB. The following commands have
3438 Print the list of Ada tasks.
3440 Print detailed information about task number N.
3442 Print the task number of the current task.
3444 Switch the context of debugging to task number N.
3446 * Support for user-defined prefixed commands. The "define" command can
3447 add new commands to existing prefixes, e.g. "target".
3449 * Multi-inferior, multi-process debugging.
3451 GDB now has generalized support for multi-inferior debugging. See
3452 "Debugging Multiple Inferiors" in the manual for more information.
3453 Although availability still depends on target support, the command
3454 set is more uniform now. The GNU/Linux specific multi-forks support
3455 has been migrated to this new framework. This implied some user
3456 visible changes; see "New commands" and also "Removed commands"
3459 * Target descriptions can now describe the target OS ABI. See the
3460 "Target Description Format" section in the user manual for more
3463 * Target descriptions can now describe "compatible" architectures
3464 to indicate that the target can execute applications for a different
3465 architecture in addition to those for the main target architecture.
3466 See the "Target Description Format" section in the user manual for
3469 * Multi-architecture debugging.
3471 GDB now includes general supports for debugging applications on
3472 hybrid systems that use more than one single processor architecture
3473 at the same time. Each such hybrid architecture still requires
3474 specific support to be added. The only hybrid architecture supported
3475 in this version of GDB is the Cell Broadband Engine.
3477 * GDB now supports integrated debugging of Cell/B.E. applications that
3478 use both the PPU and SPU architectures. To enable support for hybrid
3479 Cell/B.E. debugging, you need to configure GDB to support both the
3480 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3481 --enable-targets configure option.
3483 * Non-stop mode debugging.
3485 For some targets, GDB now supports an optional mode of operation in
3486 which you can examine stopped threads while other threads continue
3487 to execute freely. This is referred to as non-stop mode, with the
3488 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3489 section in the user manual for more information.
3491 To be able to support remote non-stop debugging, a remote stub needs
3492 to implement the non-stop mode remote protocol extensions, as
3493 described in the "Remote Non-Stop" section of the user manual. The
3494 GDB remote stub, gdbserver, has been adjusted to support these
3495 extensions on linux targets.
3497 * New commands (for set/show, see "New options" below)
3499 catch syscall [NAME(S) | NUMBER(S)]
3500 Catch system calls. Arguments, which should be names of system
3501 calls or their numbers, mean catch only those syscalls. Without
3502 arguments, every syscall will be caught. When the inferior issues
3503 any of the specified syscalls, GDB will stop and announce the system
3504 call, both when it is called and when its call returns. This
3505 feature is currently available with a native GDB running on the
3506 Linux Kernel, under the following architectures: x86, x86_64,
3507 PowerPC and PowerPC64.
3509 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3511 Search memory for a sequence of bytes.
3513 maint set python print-stack
3514 maint show python print-stack
3515 Show a stack trace when an error is encountered in a Python script.
3518 Invoke CODE by passing it to the Python interpreter.
3523 These allow macros to be defined, undefined, and listed
3527 Show operating system information about processes.
3530 List the inferiors currently under GDB's control.
3533 Switch focus to inferior number NUM.
3536 Detach from inferior number NUM.
3539 Kill inferior number NUM.
3543 set spu stop-on-load
3544 show spu stop-on-load
3545 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3547 set spu auto-flush-cache
3548 show spu auto-flush-cache
3549 Control whether to automatically flush the software-managed cache
3550 during Cell/B.E. debugging.
3552 set sh calling-convention
3553 show sh calling-convention
3554 Control the calling convention used when calling SH target functions.
3557 show debug timestamp
3558 Control display of timestamps with GDB debugging output.
3560 set disassemble-next-line
3561 show disassemble-next-line
3562 Control display of disassembled source lines or instructions when
3565 set remote noack-packet
3566 show remote noack-packet
3567 Set/show the use of remote protocol QStartNoAckMode packet. See above
3568 under "New remote packets."
3570 set remote query-attached-packet
3571 show remote query-attached-packet
3572 Control use of remote protocol `qAttached' (query-attached) packet.
3574 set remote read-siginfo-object
3575 show remote read-siginfo-object
3576 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3579 set remote write-siginfo-object
3580 show remote write-siginfo-object
3581 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3584 set remote reverse-continue
3585 show remote reverse-continue
3586 Control use of remote protocol 'bc' (reverse-continue) packet.
3588 set remote reverse-step
3589 show remote reverse-step
3590 Control use of remote protocol 'bs' (reverse-step) packet.
3592 set displaced-stepping
3593 show displaced-stepping
3594 Control displaced stepping mode. Displaced stepping is a way to
3595 single-step over breakpoints without removing them from the debuggee.
3596 Also known as "out-of-line single-stepping".
3599 show debug displaced
3600 Control display of debugging info for displaced stepping.
3602 maint set internal-error
3603 maint show internal-error
3604 Control what GDB does when an internal error is detected.
3606 maint set internal-warning
3607 maint show internal-warning
3608 Control what GDB does when an internal warning is detected.
3613 Use a wrapper program to launch programs for debugging.
3615 set multiple-symbols (all|ask|cancel)
3616 show multiple-symbols
3617 The value of this variable can be changed to adjust the debugger behavior
3618 when an expression or a breakpoint location contains an ambiguous symbol
3619 name (an overloaded function name, for instance).
3621 set breakpoint always-inserted
3622 show breakpoint always-inserted
3623 Keep breakpoints always inserted in the target, as opposed to inserting
3624 them when resuming the target, and removing them when the target stops.
3625 This option can improve debugger performance on slow remote targets.
3627 set arm fallback-mode (arm|thumb|auto)
3628 show arm fallback-mode
3629 set arm force-mode (arm|thumb|auto)
3631 These commands control how ARM GDB determines whether instructions
3632 are ARM or Thumb. The default for both settings is auto, which uses
3633 the current CPSR value for instructions without symbols; previous
3634 versions of GDB behaved as if "set arm fallback-mode arm".
3636 set disable-randomization
3637 show disable-randomization
3638 Standalone programs run with the virtual address space randomization enabled
3639 by default on some platforms. This option keeps the addresses stable across
3640 multiple debugging sessions.
3644 Control whether other threads are stopped or not when some thread hits
3649 Requests that asynchronous execution is enabled in the target, if available.
3650 In this case, it's possible to resume target in the background, and interact
3651 with GDB while the target is running. "show target-async" displays the
3652 current state of asynchronous execution of the target.
3654 set target-wide-charset
3655 show target-wide-charset
3656 The target-wide-charset is the name of the character set that GDB
3657 uses when printing characters whose type is wchar_t.
3659 set tcp auto-retry (on|off)
3661 set tcp connect-timeout
3662 show tcp connect-timeout
3663 These commands allow GDB to retry failed TCP connections to a remote stub
3664 with a specified timeout period; this is useful if the stub is launched
3665 in parallel with GDB but may not be ready to accept connections immediately.
3667 set libthread-db-search-path
3668 show libthread-db-search-path
3669 Control list of directories which GDB will search for appropriate
3672 set schedule-multiple (on|off)
3673 show schedule-multiple
3674 Allow GDB to resume all threads of all processes or only threads of
3675 the current process.
3679 Use more aggressive caching for accesses to the stack. This improves
3680 performance of remote debugging (particularly backtraces) without
3681 affecting correctness.
3683 set interactive-mode (on|off|auto)
3684 show interactive-mode
3685 Control whether GDB runs in interactive mode (on) or not (off).
3686 When in interactive mode, GDB waits for the user to answer all
3687 queries. Otherwise, GDB does not wait and assumes the default
3688 answer. When set to auto (the default), GDB determines which
3689 mode to use based on the stdin settings.
3694 For program forks, this is replaced by the new more generic `info
3695 inferiors' command. To list checkpoints, you can still use the
3696 `info checkpoints' command, which was an alias for the `info forks'
3700 Replaced by the new `inferior' command. To switch between
3701 checkpoints, you can still use the `restart' command, which was an
3702 alias for the `fork' command.
3705 This is removed, since some targets don't have a notion of
3706 processes. To switch between processes, you can still use the
3707 `inferior' command using GDB's own inferior number.
3710 For program forks, this is replaced by the new more generic `kill
3711 inferior' command. To delete a checkpoint, you can still use the
3712 `delete checkpoint' command, which was an alias for the `delete
3716 For program forks, this is replaced by the new more generic `detach
3717 inferior' command. To detach a checkpoint, you can still use the
3718 `detach checkpoint' command, which was an alias for the `detach
3721 * New native configurations
3723 x86/x86_64 Darwin i[34567]86-*-darwin*
3725 x86_64 MinGW x86_64-*-mingw*
3729 Lattice Mico32 lm32-*
3730 x86 DICOS i[34567]86-*-dicos*
3731 x86_64 DICOS x86_64-*-dicos*
3734 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3735 (mingw32ce) debugging.
3741 These commands were actually not implemented on any target.
3743 *** Changes in GDB 6.8
3745 * New native configurations
3747 NetBSD/hppa hppa*-*netbsd*
3748 Xtensa GNU/Linux xtensa*-*-linux*
3752 NetBSD/hppa hppa*-*-netbsd*
3753 Xtensa GNU/Lunux xtensa*-*-linux*
3755 * Change in command line behavior -- corefiles vs. process ids.
3757 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3758 attaching to process NUMBER fails, GDB no longer attempts to open a
3759 core file named NUMBER. Attaching to a program using the -c option
3760 is no longer supported. Instead, use the '-p' or '--pid' options.
3762 * GDB can now be built as a native debugger for debugging Windows x86
3763 (mingw32) Portable Executable (PE) programs.
3765 * Pending breakpoints no longer change their number when their address
3768 * GDB now supports breakpoints with multiple locations,
3769 including breakpoints on C++ constructors, inside C++ templates,
3770 and in inlined functions.
3772 * GDB's ability to debug optimized code has been improved. GDB more
3773 accurately identifies function bodies and lexical blocks that occupy
3774 more than one contiguous range of addresses.
3776 * Target descriptions can now describe registers for PowerPC.
3778 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3779 registers on PowerPC targets.
3781 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3782 targets even when the libthread_db library is not available.
3784 * The GDB remote stub, gdbserver, now supports the new file transfer
3785 commands (remote put, remote get, and remote delete).
3787 * The GDB remote stub, gdbserver, now supports run and attach in
3788 extended-remote mode.
3790 * hppa*64*-*-hpux11* target broken
3791 The debugger is unable to start a program and fails with the following
3792 error: "Error trying to get information about dynamic linker".
3793 The gdb-6.7 release is also affected.
3795 * GDB now supports the --enable-targets= configure option to allow
3796 building a single GDB executable that supports multiple remote
3797 target architectures.
3799 * GDB now supports debugging C and C++ programs which use the
3800 Decimal Floating Point extension. In addition, the PowerPC target
3801 now has a set of pseudo-registers to inspect decimal float values
3802 stored in two consecutive float registers.
3804 * The -break-insert MI command can optionally create pending
3807 * Improved support for debugging Ada
3808 Many improvements to the Ada language support have been made. These
3810 - Better support for Ada2005 interface types
3811 - Improved handling of arrays and slices in general
3812 - Better support for Taft-amendment types
3813 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3815 - Improved command completion in Ada
3818 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3823 set print frame-arguments (all|scalars|none)
3824 show print frame-arguments
3825 The value of this variable can be changed to control which argument
3826 values should be printed by the debugger when displaying a frame.
3831 Transfer files to and from a remote target, and delete remote files.
3838 Transfer files to and from a remote target, and delete remote files.
3840 * New remote packets
3847 Open, close, read, write, and delete files on the remote system.
3850 Attach to an existing process on the remote system, in extended-remote
3854 Run a new process on the remote system, in extended-remote mode.
3856 *** Changes in GDB 6.7
3858 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3859 bfd, libiberty and opcodes, as revealed by static analysis donated by
3860 Coverity, Inc. (http://scan.coverity.com).
3862 * When looking up multiply-defined global symbols, GDB will now prefer the
3863 symbol definition in the current shared library if it was built using the
3864 -Bsymbolic linker option.
3866 * When the Text User Interface (TUI) is not configured, GDB will now
3867 recognize the -tui command-line option and print a message that the TUI
3870 * The GDB remote stub, gdbserver, now has lower overhead for high
3871 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3873 * GDB for MIPS targets now autodetects whether a remote target provides
3874 32-bit or 64-bit register values.
3876 * Support for C++ member pointers has been improved.
3878 * GDB now understands XML target descriptions, which specify the
3879 target's overall architecture. GDB can read a description from
3880 a local file or over the remote serial protocol.
3882 * Vectors of single-byte data use a new integer type which is not
3883 automatically displayed as character or string data.
3885 * The /s format now works with the print command. It displays
3886 arrays of single-byte integers and pointers to single-byte integers
3889 * Target descriptions can now describe target-specific registers,
3890 for architectures which have implemented the support (currently
3891 only ARM, M68K, and MIPS).
3893 * GDB and the GDB remote stub, gdbserver, now support the XScale
3896 * The GDB remote stub, gdbserver, has been updated to support
3897 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3898 has been rewritten to use the standard GDB remote protocol.
3900 * GDB can now step into C++ functions which are called through thunks.
3902 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3904 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3905 layout. It also supports a TextSeg= and DataSeg= response when only
3906 segment base addresses (rather than offsets) are available.
3908 * The /i format now outputs any trailing branch delay slot instructions
3909 immediately following the last instruction within the count specified.
3911 * The GDB remote protocol "T" stop reply packet now supports a
3912 "library" response. Combined with the new "qXfer:libraries:read"
3913 packet, this response allows GDB to debug shared libraries on targets
3914 where the operating system manages the list of loaded libraries (e.g.
3915 Windows and SymbianOS).
3917 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3918 (DLLs) on Windows and Windows CE targets.
3920 * GDB now supports a faster verification that a .debug file matches its binary
3921 according to its build-id signature, if the signature is present.
3927 Enable or disable hardware flow control (RTS/CTS) on the serial port
3928 when debugging using remote targets.
3930 set mem inaccessible-by-default
3931 show mem inaccessible-by-default
3932 If the target supplies a memory map, for instance via the remote
3933 protocol's "qXfer:memory-map:read" packet, setting this variable
3934 prevents GDB from accessing memory outside the memory map. This
3935 is useful for targets with memory mapped registers or which react
3936 badly to accesses of unmapped address space.
3938 set breakpoint auto-hw
3939 show breakpoint auto-hw
3940 If the target supplies a memory map, for instance via the remote
3941 protocol's "qXfer:memory-map:read" packet, setting this variable
3942 lets GDB use hardware breakpoints automatically for memory regions
3943 where it can not use software breakpoints. This covers both the
3944 "break" command and internal breakpoints used for other commands
3945 including "next" and "finish".
3948 catch exception unhandled
3949 Stop the program execution when Ada exceptions are raised.
3952 Stop the program execution when an Ada assertion failed.
3956 Set an alternate system root for target files. This is a more
3957 general version of "set solib-absolute-prefix", which is now
3958 an alias to "set sysroot".
3961 Provide extended SPU facility status information. This set of
3962 commands is available only when debugging the Cell/B.E. SPU
3965 * New native configurations
3967 OpenBSD/sh sh*-*openbsd*
3970 unset tdesc filename
3972 Use the specified local file as an XML target description, and do
3973 not query the target for its built-in description.
3977 OpenBSD/sh sh*-*-openbsd*
3978 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3979 Toshiba Media Processor mep-elf
3981 * New remote packets
3984 Ignore the specified signals; pass them directly to the debugged program
3985 without stopping other threads or reporting them to GDB.
3987 qXfer:features:read:
3988 Read an XML target description from the target, which describes its
3993 Read or write contents of an spufs file on the target system. These
3994 packets are available only on the Cell/B.E. SPU architecture.
3996 qXfer:libraries:read:
3997 Report the loaded shared libraries. Combined with new "T" packet
3998 response, this packet allows GDB to debug shared libraries on
3999 targets where the operating system manages the list of loaded
4000 libraries (e.g. Windows and SymbianOS).
4004 Support for these obsolete configurations has been removed.
4012 i[34567]86-*-lynxos*
4013 i[34567]86-*-netware*
4014 i[34567]86-*-sco3.2v5*
4015 i[34567]86-*-sco3.2v4*
4017 i[34567]86-*-sysv4.2*
4020 i[34567]86-*-unixware2*
4021 i[34567]86-*-unixware*
4030 * Other removed features
4037 Various m68k-only ROM monitors.
4044 Various Renesas ROM monitors and debugging interfaces for SH and
4049 Support for a Macraigor serial interface to on-chip debugging.
4050 GDB does not directly support the newer parallel or USB
4055 A debug information format. The predecessor to DWARF 2 and
4056 DWARF 3, which are still supported.
4058 Support for the HP aCC compiler on HP-UX/PA-RISC
4060 SOM-encapsulated symbolic debugging information, automatic
4061 invocation of pxdb, and the aCC custom C++ ABI. This does not
4062 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4063 with aCC can still be debugged on an assembly level.
4065 MIPS ".pdr" sections
4067 A MIPS-specific format used to describe stack frame layout
4068 in debugging information.
4072 GDB could work with an older version of Guile to debug
4073 the interpreter and Scheme programs running in it.
4075 set mips stack-arg-size
4076 set mips saved-gpreg-size
4078 Use "set mips abi" to control parameter passing for MIPS.
4080 *** Changes in GDB 6.6
4085 Cell Broadband Engine SPU spu-elf
4087 * GDB can now be configured as a cross-debugger targeting native Windows
4088 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4089 running on a Windows system over TCP/IP to debug Windows programs.
4091 * The GDB remote stub, gdbserver, has been updated to support Windows and
4092 Cygwin debugging. Both single-threaded and multi-threaded programs are
4095 * The "set trust-readonly-sections" command works again. This command was
4096 broken in GDB 6.3, 6.4, and 6.5.
4098 * The "load" command now supports writing to flash memory, if the remote
4099 stub provides the required support.
4101 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4102 longer requires symbolic debug information (e.g. DWARF-2).
4107 unset substitute-path
4108 show substitute-path
4109 Manage a list of substitution rules that GDB uses to rewrite the name
4110 of the directories where the sources are located. This can be useful
4111 for instance when the sources were moved to a different location
4112 between compilation and debugging.
4116 Print each CLI command as it is executed. Each command is prefixed with
4117 a number of `+' symbols representing the nesting depth.
4118 The source command now has a `-v' option to enable the same feature.
4122 The ARM Demon monitor support (RDP protocol, "target rdp").
4124 Kernel Object Display, an embedded debugging feature which only worked with
4125 an obsolete version of Cisco IOS.
4127 The 'set download-write-size' and 'show download-write-size' commands.
4129 * New remote packets
4132 Tell a stub about GDB client features, and request remote target features.
4133 The first feature implemented is PacketSize, which allows the target to
4134 specify the size of packets it can handle - to minimize the number of
4135 packets required and improve performance when connected to a remote
4139 Fetch an OS auxilliary vector from the remote stub. This packet is a
4140 more efficient replacement for qPart:auxv:read.
4142 qXfer:memory-map:read:
4143 Fetch a memory map from the remote stub, including information about
4144 RAM, ROM, and flash memory devices.
4149 Erase and program a flash memory device.
4151 * Removed remote packets
4154 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4155 used it, and only gdbserver implemented it.
4157 *** Changes in GDB 6.5
4161 Renesas M32C/M16C m32c-elf
4163 Morpho Technologies ms1 ms1-elf
4167 init-if-undefined Initialize a convenience variable, but
4168 only if it doesn't already have a value.
4170 The following commands are presently only implemented for native GNU/Linux:
4172 checkpoint Save a snapshot of the program state.
4174 restart <n> Return the program state to a
4175 previously saved state.
4177 info checkpoints List currently saved checkpoints.
4179 delete-checkpoint <n> Delete a previously saved checkpoint.
4181 set|show detach-on-fork Tell gdb whether to detach from a newly
4182 forked process, or to keep debugging it.
4184 info forks List forks of the user program that
4185 are available to be debugged.
4187 fork <n> Switch to debugging one of several
4188 forks of the user program that are
4189 available to be debugged.
4191 delete-fork <n> Delete a fork from the list of forks
4192 that are available to be debugged (and
4193 kill the forked process).
4195 detach-fork <n> Delete a fork from the list of forks
4196 that are available to be debugged (and
4197 allow the process to continue).
4201 Morpho Technologies ms2 ms1-elf
4203 * Improved Windows host support
4205 GDB now builds as a cross debugger hosted on i686-mingw32, including
4206 native console support, and remote communications using either
4207 network sockets or serial ports.
4209 * Improved Modula-2 language support
4211 GDB can now print most types in the Modula-2 syntax. This includes:
4212 basic types, set types, record types, enumerated types, range types,
4213 pointer types and ARRAY types. Procedure var parameters are correctly
4214 printed and hexadecimal addresses and character constants are also
4215 written in the Modula-2 syntax. Best results can be obtained by using
4216 GNU Modula-2 together with the -gdwarf-2 command line option.
4220 The ARM rdi-share module.
4222 The Netware NLM debug server.
4224 *** Changes in GDB 6.4
4226 * New native configurations
4228 OpenBSD/arm arm*-*-openbsd*
4229 OpenBSD/mips64 mips64-*-openbsd*
4233 Morpho Technologies ms1 ms1-elf
4235 * New command line options
4237 --batch-silent As for --batch, but totally silent.
4238 --return-child-result The debugger will exist with the same value
4239 the child (debugged) program exited with.
4240 --eval-command COMMAND, -ex COMMAND
4241 Execute a single GDB CLI command. This may be
4242 specified multiple times and in conjunction
4243 with the --command (-x) option.
4245 * Deprecated commands removed
4247 The following commands, that were deprecated in 2000, have been
4251 set|show arm disassembly-flavor set|show arm disassembler
4252 othernames set arm disassembler
4253 set|show remotedebug set|show debug remote
4254 set|show archdebug set|show debug arch
4255 set|show eventdebug set|show debug event
4258 * New BSD user-level threads support
4260 It is now possible to debug programs using the user-level threads
4261 library on OpenBSD and FreeBSD. Currently supported (target)
4264 FreeBSD/amd64 x86_64-*-freebsd*
4265 FreeBSD/i386 i386-*-freebsd*
4266 OpenBSD/i386 i386-*-openbsd*
4268 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4269 are not yet supported.
4271 * New support for Matsushita MN10300 w/sim added
4272 (Work in progress). mn10300-elf.
4274 * REMOVED configurations and files
4276 VxWorks and the XDR protocol *-*-vxworks
4277 Motorola MCORE mcore-*-*
4278 National Semiconductor NS32000 ns32k-*-*
4280 * New "set print array-indexes" command
4282 After turning this setting "on", GDB prints the index of each element
4283 when displaying arrays. The default is "off" to preserve the previous
4286 * VAX floating point support
4288 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4290 * User-defined command support
4292 In addition to using $arg0..$arg9 for argument passing, it is now possible
4293 to use $argc to determine now many arguments have been passed. See the
4294 section on user-defined commands in the user manual for more information.
4296 *** Changes in GDB 6.3:
4298 * New command line option
4300 GDB now accepts -l followed by a number to set the timeout for remote
4303 * GDB works with GCC -feliminate-dwarf2-dups
4305 GDB now supports a more compact representation of DWARF-2 debug
4306 information using DW_FORM_ref_addr references. These are produced
4307 by GCC with the option -feliminate-dwarf2-dups and also by some
4308 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4309 to use -feliminate-dwarf2-dups.
4311 * Internationalization
4313 When supported by the host system, GDB will be built with
4314 internationalization (libintl). The task of marking up the sources is
4315 continued, we're looking forward to our first translation.
4319 Initial support for debugging programs compiled with the GNAT
4320 implementation of the Ada programming language has been integrated
4321 into GDB. In this release, support is limited to expression evaluation.
4323 * New native configurations
4325 GNU/Linux/m32r m32r-*-linux-gnu
4329 GDB's remote protocol now includes support for the 'p' packet. This
4330 packet is used to fetch individual registers from a remote inferior.
4332 * END-OF-LIFE registers[] compatibility module
4334 GDB's internal register infrastructure has been completely rewritten.
4335 The new infrastructure making possible the implementation of key new
4336 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4339 GDB 6.3 will be the last release to include the the registers[]
4340 compatibility module that allowed out-of-date configurations to
4341 continue to work. This change directly impacts the following
4351 powerpc bdm protocol
4353 Unless there is activity to revive these configurations, they will be
4354 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4356 * OBSOLETE configurations and files
4358 Configurations that have been declared obsolete in this release have
4359 been commented out. Unless there is activity to revive these
4360 configurations, the next release of GDB will have their sources
4361 permanently REMOVED.
4370 *** Changes in GDB 6.2.1:
4372 * MIPS `break main; run' gave an heuristic-fence-post warning
4374 When attempting to run even a simple program, a warning about
4375 heuristic-fence-post being hit would be reported. This problem has
4378 * MIPS IRIX 'long double' crashed GDB
4380 When examining a long double variable, GDB would get a segmentation
4381 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4382 IRIX long double values).
4386 A bug in the VAX stack code was causing problems with the "next"
4387 command. This problem has been fixed.
4389 *** Changes in GDB 6.2:
4391 * Fix for ``many threads''
4393 On GNU/Linux systems that use the NPTL threads library, a program
4394 rapidly creating and deleting threads would confuse GDB leading to the
4397 ptrace: No such process.
4398 thread_db_get_info: cannot get thread info: generic error
4400 This problem has been fixed.
4402 * "-async" and "-noasync" options removed.
4404 Support for the broken "-noasync" option has been removed (it caused
4407 * New ``start'' command.
4409 This command runs the program until the begining of the main procedure.
4411 * New BSD Kernel Data Access Library (libkvm) interface
4413 Using ``target kvm'' it is now possible to debug kernel core dumps and
4414 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4415 platforms. Currently supported (native-only) configurations are:
4417 FreeBSD/amd64 x86_64-*-freebsd*
4418 FreeBSD/i386 i?86-*-freebsd*
4419 NetBSD/i386 i?86-*-netbsd*
4420 NetBSD/m68k m68*-*-netbsd*
4421 NetBSD/sparc sparc-*-netbsd*
4422 OpenBSD/amd64 x86_64-*-openbsd*
4423 OpenBSD/i386 i?86-*-openbsd*
4424 OpenBSD/m68k m68*-openbsd*
4425 OpenBSD/sparc sparc-*-openbsd*
4427 * Signal trampoline code overhauled
4429 Many generic problems with GDB's signal handling code have been fixed.
4430 These include: backtraces through non-contiguous stacks; recognition
4431 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4432 call; backtrace through a signal trampoline; step into and out of
4433 signal handlers; and single-stepping in the signal trampoline.
4435 Please note that kernel bugs are a limiting factor here. These
4436 features have been shown to work on an s390 GNU/Linux system that
4437 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4439 * Cygwin support for DWARF 2 added.
4441 * New native configurations
4443 GNU/Linux/hppa hppa*-*-linux*
4444 OpenBSD/hppa hppa*-*-openbsd*
4445 OpenBSD/m68k m68*-*-openbsd*
4446 OpenBSD/m88k m88*-*-openbsd*
4447 OpenBSD/powerpc powerpc-*-openbsd*
4448 NetBSD/vax vax-*-netbsd*
4449 OpenBSD/vax vax-*-openbsd*
4451 * END-OF-LIFE frame compatibility module
4453 GDB's internal frame infrastructure has been completely rewritten.
4454 The new infrastructure making it possible to support key new features
4455 including DWARF 2 Call Frame Information. To aid in the task of
4456 migrating old configurations to this new infrastructure, a
4457 compatibility module, that allowed old configurations to continue to
4458 work, was also included.
4460 GDB 6.2 will be the last release to include this frame compatibility
4461 module. This change directly impacts the following configurations:
4471 Unless there is activity to revive these configurations, they will be
4472 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4474 * REMOVED configurations and files
4476 Sun 3, running SunOS 3 m68*-*-sunos3*
4477 Sun 3, running SunOS 4 m68*-*-sunos4*
4478 Sun 2, running SunOS 3 m68000-*-sunos3*
4479 Sun 2, running SunOS 4 m68000-*-sunos4*
4480 Motorola 680x0 running LynxOS m68*-*-lynxos*
4481 AT&T 3b1/Unix pc m68*-att-*
4482 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4483 decstation mips-dec-* mips-little-*
4484 riscos mips-*-riscos* mips-*-sysv*
4485 sonymips mips-sony-*
4486 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4488 *** Changes in GDB 6.1.1:
4490 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4492 The TUI (Text-mode User Interface) is now built as part of a default
4493 GDB configuration. It is enabled by either selecting the TUI with the
4494 command line option "-i=tui" or by running the separate "gdbtui"
4495 program. For more information on the TUI, see the manual "Debugging
4498 * Pending breakpoint support (also included in GDB 6.1)
4500 Support has been added to allow you to specify breakpoints in shared
4501 libraries that have not yet been loaded. If a breakpoint location
4502 cannot be found, and the "breakpoint pending" option is set to auto,
4503 GDB queries you if you wish to make the breakpoint pending on a future
4504 shared-library load. If and when GDB resolves the breakpoint symbol,
4505 the pending breakpoint is removed as one or more regular breakpoints
4508 Pending breakpoints are very useful for GCJ Java debugging.
4510 * Fixed ISO-C build problems
4512 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4513 non ISO-C code that stopped them being built using a more strict ISO-C
4514 compiler (e.g., IBM's C compiler).
4516 * Fixed build problem on IRIX 5
4518 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4519 wasn't able to compile compile on an IRIX 5 system.
4521 * Added execute permission to gdb/gdbserver/configure
4523 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4524 permission. This bug would cause configure to fail on a number of
4525 systems (Solaris, IRIX). Ref: server/519.
4527 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4529 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4530 has been updated to use constant array sizes.
4532 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4534 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4535 its generated DWARF Call Frame Info. This encoding was causing GDB to
4536 panic, that panic has been fixed. Ref: gdb/1628.
4538 * Fixed a problem when examining parameters in shared library code.
4540 When examining parameters in optimized shared library code generated
4541 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4542 not available''. GDB now correctly displays the variable's value.
4544 *** Changes in GDB 6.1:
4546 * Removed --with-mmalloc
4548 Support for the mmalloc memory manager has been removed, as it
4549 conflicted with the internal gdb byte cache.
4551 * Changes in AMD64 configurations
4553 The AMD64 target now includes the %cs and %ss registers. As a result
4554 the AMD64 remote protocol has changed; this affects the floating-point
4555 and SSE registers. If you rely on those registers for your debugging,
4556 you should upgrade gdbserver on the remote side.
4558 * Revised SPARC target
4560 The SPARC target has been completely revised, incorporating the
4561 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4562 support for LynxOS and SunOS 4 has been dropped. Calling functions
4563 from within GDB on operating systems with a non-executable stack
4564 (Solaris, OpenBSD) now works.
4568 GDB has a new C++ demangler which does a better job on the mangled
4569 names generated by current versions of g++. It also runs faster, so
4570 with this and other changes gdb should now start faster on large C++
4573 * DWARF 2 Location Expressions
4575 GDB support for location expressions has been extended to support function
4576 arguments and frame bases. Older versions of GDB could crash when they
4579 * C++ nested types and namespaces
4581 GDB's support for nested types and namespaces in C++ has been
4582 improved, especially if you use the DWARF 2 debugging format. (This
4583 is the default for recent versions of GCC on most platforms.)
4584 Specifically, if you have a class "Inner" defined within a class or
4585 namespace "Outer", then GDB realizes that the class's name is
4586 "Outer::Inner", not simply "Inner". This should greatly reduce the
4587 frequency of complaints about not finding RTTI symbols. In addition,
4588 if you are stopped at inside of a function defined within a namespace,
4589 GDB modifies its name lookup accordingly.
4591 * New native configurations
4593 NetBSD/amd64 x86_64-*-netbsd*
4594 OpenBSD/amd64 x86_64-*-openbsd*
4595 OpenBSD/alpha alpha*-*-openbsd*
4596 OpenBSD/sparc sparc-*-openbsd*
4597 OpenBSD/sparc64 sparc64-*-openbsd*
4599 * New debugging protocols
4601 M32R with SDI protocol m32r-*-elf*
4603 * "set prompt-escape-char" command deleted.
4605 The command "set prompt-escape-char" has been deleted. This command,
4606 and its very obscure effet on GDB's prompt, was never documented,
4607 tested, nor mentioned in the NEWS file.
4609 * OBSOLETE configurations and files
4611 Configurations that have been declared obsolete in this release have
4612 been commented out. Unless there is activity to revive these
4613 configurations, the next release of GDB will have their sources
4614 permanently REMOVED.
4616 Sun 3, running SunOS 3 m68*-*-sunos3*
4617 Sun 3, running SunOS 4 m68*-*-sunos4*
4618 Sun 2, running SunOS 3 m68000-*-sunos3*
4619 Sun 2, running SunOS 4 m68000-*-sunos4*
4620 Motorola 680x0 running LynxOS m68*-*-lynxos*
4621 AT&T 3b1/Unix pc m68*-att-*
4622 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4623 decstation mips-dec-* mips-little-*
4624 riscos mips-*-riscos* mips-*-sysv*
4625 sonymips mips-sony-*
4626 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4628 * REMOVED configurations and files
4630 SGI Irix-4.x mips-sgi-irix4 or iris4
4631 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4632 Z8000 simulator z8k-zilog-none or z8ksim
4633 Matsushita MN10200 w/simulator mn10200-*-*
4634 H8/500 simulator h8500-hitachi-hms or h8500hms
4635 HP/PA running BSD hppa*-*-bsd*
4636 HP/PA running OSF/1 hppa*-*-osf*
4637 HP/PA Pro target hppa*-*-pro*
4638 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4639 386BSD i[3456]86-*-bsd*
4640 Sequent family i[3456]86-sequent-sysv4*
4641 i[3456]86-sequent-sysv*
4642 i[3456]86-sequent-bsd*
4643 SPARC running LynxOS sparc-*-lynxos*
4644 SPARC running SunOS 4 sparc-*-sunos4*
4645 Tsqware Sparclet sparclet-*-*
4646 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4648 *** Changes in GDB 6.0:
4652 Support for debugging the Objective-C programming language has been
4653 integrated into GDB.
4655 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4657 DWARF 2's Call Frame Information makes available compiler generated
4658 information that more exactly describes the program's run-time stack.
4659 By using this information, GDB is able to provide more robust stack
4662 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4663 have been updated to use a new backtrace mechanism which includes
4664 DWARF 2 CFI support.
4668 GDB's remote protocol has been extended to include support for hosted
4669 file I/O (where the remote target uses GDB's file system). See GDB's
4670 remote protocol documentation for details.
4672 * All targets using the new architecture framework.
4674 All of GDB's targets have been updated to use the new internal
4675 architecture framework. The way is now open for future GDB releases
4676 to include cross-architecture native debugging support (i386 on amd64,
4679 * GNU/Linux's Thread Local Storage (TLS)
4681 GDB now includes support for for the GNU/Linux implementation of
4682 per-thread variables.
4684 * GNU/Linux's Native POSIX Thread Library (NPTL)
4686 GDB's thread code has been updated to work with either the new
4687 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4689 * Separate debug info.
4691 GDB, in conjunction with BINUTILS, now supports a mechanism for
4692 automatically loading debug information from a separate file. Instead
4693 of shipping full debug and non-debug versions of system libraries,
4694 system integrators can now instead ship just the stripped libraries
4695 and optional debug files.
4697 * DWARF 2 Location Expressions
4699 DWARF 2 Location Expressions allow the compiler to more completely
4700 describe the location of variables (even in optimized code) to the
4703 GDB now includes preliminary support for location expressions (support
4704 for DW_OP_piece is still missing).
4708 A number of long standing bugs that caused GDB to die while starting a
4709 Java application have been fixed. GDB's Java support is now
4710 considered "useable".
4712 * GNU/Linux support for fork, vfork, and exec.
4714 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4715 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4718 * GDB supports logging output to a file
4720 There are two new commands, "set logging" and "show logging", which can be
4721 used to capture GDB's output to a file.
4723 * The meaning of "detach" has changed for gdbserver
4725 The "detach" command will now resume the application, as documented. To
4726 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4729 * d10v, m68hc11 `regs' command deprecated
4731 The `info registers' command has been updated so that it displays the
4732 registers using a format identical to the old `regs' command.
4736 A new command, "maint set profile on/off", has been added. This command can
4737 be used to enable or disable profiling while running GDB, to profile a
4738 session or a set of commands. In addition there is a new configure switch,
4739 "--enable-profiling", which will cause GDB to be compiled with profiling
4740 data, for more informative profiling results.
4742 * Default MI syntax changed to "mi2".
4744 The default MI (machine interface) syntax, enabled by the command line
4745 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4746 "mi1", can be enabled by specifying the option "-i=mi1".
4748 Support for the original "mi0" syntax (included in GDB 5.0) has been
4751 Fix for gdb/192: removed extraneous space when displaying frame level.
4752 Fix for gdb/672: update changelist is now output in mi list format.
4753 Fix for gdb/702: a -var-assign that updates the value now shows up
4754 in a subsequent -var-update.
4756 * New native configurations.
4758 FreeBSD/amd64 x86_64-*-freebsd*
4760 * Multi-arched targets.
4762 HP/PA HPUX11 hppa*-*-hpux*
4763 Renesas M32R/D w/simulator m32r-*-elf*
4765 * OBSOLETE configurations and files
4767 Configurations that have been declared obsolete in this release have
4768 been commented out. Unless there is activity to revive these
4769 configurations, the next release of GDB will have their sources
4770 permanently REMOVED.
4772 Z8000 simulator z8k-zilog-none or z8ksim
4773 Matsushita MN10200 w/simulator mn10200-*-*
4774 H8/500 simulator h8500-hitachi-hms or h8500hms
4775 HP/PA running BSD hppa*-*-bsd*
4776 HP/PA running OSF/1 hppa*-*-osf*
4777 HP/PA Pro target hppa*-*-pro*
4778 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4779 Sequent family i[3456]86-sequent-sysv4*
4780 i[3456]86-sequent-sysv*
4781 i[3456]86-sequent-bsd*
4782 Tsqware Sparclet sparclet-*-*
4783 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4785 * REMOVED configurations and files
4788 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4789 IBM AIX PS/2 i[3456]86-*-aix
4790 i386 running Mach 3.0 i[3456]86-*-mach3*
4791 i386 running Mach i[3456]86-*-mach*
4792 i386 running OSF/1 i[3456]86-*osf1mk*
4793 HP/Apollo 68k Family m68*-apollo*-sysv*,
4795 m68*-hp-bsd*, m68*-hp-hpux*
4796 Argonaut Risc Chip (ARC) arc-*-*
4797 Mitsubishi D30V d30v-*-*
4798 Fujitsu FR30 fr30-*-elf*
4799 OS/9000 i[34]86-*-os9k
4800 I960 with MON960 i960-*-coff
4802 * MIPS $fp behavior changed
4804 The convenience variable $fp, for the MIPS, now consistently returns
4805 the address of the current frame's base. Previously, depending on the
4806 context, $fp could refer to either $sp or the current frame's base
4807 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4808 The GNU Source-Level Debugger''.
4810 *** Changes in GDB 5.3:
4812 * GNU/Linux shared library multi-threaded performance improved.
4814 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4815 `/proc', in preference to `ptrace' for memory reads. This may result
4816 in an improvement in the start-up time of multi-threaded, shared
4817 library applications when run under GDB. One GDB user writes: ``loads
4818 shared libs like mad''.
4820 * ``gdbserver'' now supports multi-threaded applications on some targets
4822 Support for debugging multi-threaded applications which use
4823 the GNU/Linux LinuxThreads package has been added for
4824 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4825 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4827 * GDB now supports C/C++ preprocessor macros.
4829 GDB now expands preprocessor macro invocations in C/C++ expressions,
4830 and provides various commands for showing macro definitions and how
4833 The new command `macro expand EXPRESSION' expands any macro
4834 invocations in expression, and shows the result.
4836 The new command `show macro MACRO-NAME' shows the definition of the
4837 macro named MACRO-NAME, and where it was defined.
4839 Most compilers don't include information about macros in the debugging
4840 information by default. In GCC 3.1, for example, you need to compile
4841 your program with the options `-gdwarf-2 -g3'. If the macro
4842 information is present in the executable, GDB will read it.
4844 * Multi-arched targets.
4846 DEC Alpha (partial) alpha*-*-*
4847 DEC VAX (partial) vax-*-*
4849 National Semiconductor NS32000 (partial) ns32k-*-*
4850 Motorola 68000 (partial) m68k-*-*
4851 Motorola MCORE mcore-*-*
4855 Fujitsu FRV architecture added by Red Hat frv*-*-*
4858 * New native configurations
4860 Alpha NetBSD alpha*-*-netbsd*
4861 SH NetBSD sh*-*-netbsdelf*
4862 MIPS NetBSD mips*-*-netbsd*
4863 UltraSPARC NetBSD sparc64-*-netbsd*
4865 * OBSOLETE configurations and files
4867 Configurations that have been declared obsolete in this release have
4868 been commented out. Unless there is activity to revive these
4869 configurations, the next release of GDB will have their sources
4870 permanently REMOVED.
4872 Mitsubishi D30V d30v-*-*
4873 OS/9000 i[34]86-*-os9k
4874 IBM AIX PS/2 i[3456]86-*-aix
4875 Fujitsu FR30 fr30-*-elf*
4876 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4877 Argonaut Risc Chip (ARC) arc-*-*
4878 i386 running Mach 3.0 i[3456]86-*-mach3*
4879 i386 running Mach i[3456]86-*-mach*
4880 i386 running OSF/1 i[3456]86-*osf1mk*
4881 HP/Apollo 68k Family m68*-apollo*-sysv*,
4883 m68*-hp-bsd*, m68*-hp-hpux*
4884 I960 with MON960 i960-*-coff
4886 * OBSOLETE languages
4888 CHILL, a Pascal like language used by telecommunications companies.
4890 * REMOVED configurations and files
4892 AMD 29k family via UDI a29k-amd-udi, udi29k
4893 A29K VxWorks a29k-*-vxworks
4894 AMD 29000 embedded, using EBMON a29k-none-none
4895 AMD 29000 embedded with COFF a29k-none-coff
4896 AMD 29000 embedded with a.out a29k-none-aout
4898 testsuite/gdb.hp/gdb.threads-hp/ directory
4900 * New command "set max-user-call-depth <nnn>"
4902 This command allows the user to limit the call depth of user-defined
4903 commands. The default is 1024.
4905 * Changes in FreeBSD/i386 native debugging.
4907 Support for the "generate-core-file" has been added.
4909 * New commands "dump", "append", and "restore".
4911 These commands allow data to be copied from target memory
4912 to a bfd-format or binary file (dump and append), and back
4913 from a file into memory (restore).
4915 * Improved "next/step" support on multi-processor Alpha Tru64.
4917 The previous single-step mechanism could cause unpredictable problems,
4918 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4919 of a software single-step mechanism prevents this.
4921 *** Changes in GDB 5.2.1:
4929 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4930 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4931 Fix, by Joel Brobecker imported from mainline.
4933 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4934 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4935 Fix, by Fred Fish, imported from mainline.
4937 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4938 Surprisingly enough, it works now.
4939 By Michal Ludvig, imported from mainline.
4941 i386 hardware watchpoint support:
4942 avoid misses on second run for some targets.
4943 By Pierre Muller, imported from mainline.
4945 *** Changes in GDB 5.2:
4947 * New command "set trust-readonly-sections on[off]".
4949 This command is a hint that tells gdb that read-only sections
4950 really are read-only (ie. that their contents will not change).
4951 In this mode, gdb will go to the object file rather than the
4952 target to read memory from read-only sections (such as ".text").
4953 This can be a significant performance improvement on some
4954 (notably embedded) targets.
4956 * New command "generate-core-file" (or "gcore").
4958 This new gdb command allows the user to drop a core file of the child
4959 process state at any time. So far it's been implemented only for
4960 GNU/Linux and Solaris, but should be relatively easily ported to other
4961 hosts. Argument is core file name (defaults to core.<pid>).
4963 * New command line option
4965 GDB now accepts --pid or -p followed by a process id.
4967 * Change in command line behavior -- corefiles vs. process ids.
4969 There is a subtle behavior in the way in which GDB handles
4970 command line arguments. The first non-flag argument is always
4971 a program to debug, but the second non-flag argument may either
4972 be a corefile or a process id. Previously, GDB would attempt to
4973 open the second argument as a corefile, and if that failed, would
4974 issue a superfluous error message and then attempt to attach it as
4975 a process. Now, if the second argument begins with a non-digit,
4976 it will be treated as a corefile. If it begins with a digit,
4977 GDB will attempt to attach it as a process, and if no such process
4978 is found, will then attempt to open it as a corefile.
4980 * Changes in ARM configurations.
4982 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4983 configuration is fully multi-arch.
4985 * New native configurations
4987 ARM NetBSD arm*-*-netbsd*
4988 x86 OpenBSD i[3456]86-*-openbsd*
4989 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4990 Sparc64 running FreeBSD sparc64-*-freebsd*
4994 Sanyo XStormy16 xstormy16-elf
4996 * OBSOLETE configurations and files
4998 Configurations that have been declared obsolete in this release have
4999 been commented out. Unless there is activity to revive these
5000 configurations, the next release of GDB will have their sources
5001 permanently REMOVED.
5003 AMD 29k family via UDI a29k-amd-udi, udi29k
5004 A29K VxWorks a29k-*-vxworks
5005 AMD 29000 embedded, using EBMON a29k-none-none
5006 AMD 29000 embedded with COFF a29k-none-coff
5007 AMD 29000 embedded with a.out a29k-none-aout
5009 testsuite/gdb.hp/gdb.threads-hp/ directory
5011 * REMOVED configurations and files
5013 TI TMS320C80 tic80-*-*
5015 PowerPC Solaris powerpcle-*-solaris*
5016 PowerPC Windows NT powerpcle-*-cygwin32
5017 PowerPC Netware powerpc-*-netware*
5018 Harris/CXUX m88k m88*-harris-cxux*
5019 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5020 ns32k-utek-sysv* ns32k-utek-*
5021 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5022 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5023 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5024 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5025 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5027 * Changes to command line processing
5029 The new `--args' feature can be used to specify command-line arguments
5030 for the inferior from gdb's command line.
5032 * Changes to key bindings
5034 There is a new `operate-and-get-next' function bound to `C-o'.
5036 *** Changes in GDB 5.1.1
5038 Fix compile problem on DJGPP.
5040 Fix a problem with floating-point registers on the i386 being
5043 Fix to stop GDB crashing on .debug_str debug info.
5045 Numerous documentation fixes.
5047 Numerous testsuite fixes.
5049 *** Changes in GDB 5.1:
5051 * New native configurations
5053 Alpha FreeBSD alpha*-*-freebsd*
5054 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5055 MIPS GNU/Linux mips*-*-linux*
5056 MIPS SGI Irix 6.x mips*-sgi-irix6*
5057 ia64 AIX ia64-*-aix*
5058 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5062 Motorola 68HC11 and 68HC12 m68hc11-elf
5064 UltraSparc running GNU/Linux sparc64-*-linux*
5066 * OBSOLETE configurations and files
5068 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5069 Harris/CXUX m88k m88*-harris-cxux*
5070 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5071 ns32k-utek-sysv* ns32k-utek-*
5072 TI TMS320C80 tic80-*-*
5074 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5075 PowerPC Solaris powerpcle-*-solaris*
5076 PowerPC Windows NT powerpcle-*-cygwin32
5077 PowerPC Netware powerpc-*-netware*
5078 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5079 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5080 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5081 Apple Macintosh (MPW) host N/A
5083 stuff.c (Program to stuff files into a specially prepared space in kdb)
5084 kdb-start.c (Main loop for the standalone kernel debugger)
5086 Configurations that have been declared obsolete in this release have
5087 been commented out. Unless there is activity to revive these
5088 configurations, the next release of GDB will have their sources
5089 permanently REMOVED.
5091 * REMOVED configurations and files
5093 Altos 3068 m68*-altos-*
5094 Convex c1-*-*, c2-*-*
5096 ARM RISCix arm-*-* (as host)
5100 * GDB has been converted to ISO C.
5102 GDB's source code has been converted to ISO C. In particular, the
5103 sources are fully protoized, and rely on standard headers being
5108 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5110 * The MI enabled by default.
5112 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5113 revised and enabled by default. Packages which use GDB as a debugging
5114 engine behind a UI or another front end are encouraged to switch to
5115 using the GDB/MI interface, instead of the old annotations interface
5116 which is now deprecated.
5118 * Support for debugging Pascal programs.
5120 GDB now includes support for debugging Pascal programs. The following
5121 main features are supported:
5123 - Pascal-specific data types such as sets;
5125 - automatic recognition of Pascal sources based on file-name
5128 - Pascal-style display of data types, variables, and functions;
5130 - a Pascal expression parser.
5132 However, some important features are not yet supported.
5134 - Pascal string operations are not supported at all;
5136 - there are some problems with boolean types;
5138 - Pascal type hexadecimal constants are not supported
5139 because they conflict with the internal variables format;
5141 - support for Pascal objects and classes is not full yet;
5143 - unlike Pascal, GDB is case-sensitive for symbol names.
5145 * Changes in completion.
5147 Commands such as `shell', `run' and `set args', which pass arguments
5148 to inferior programs, now complete on file names, similar to what
5149 users expect at the shell prompt.
5151 Commands which accept locations, such as `disassemble', `print',
5152 `breakpoint', `until', etc. now complete on filenames as well as
5153 program symbols. Thus, if you type "break foob TAB", and the source
5154 files linked into the programs include `foobar.c', that file name will
5155 be one of the candidates for completion. However, file names are not
5156 considered for completion after you typed a colon that delimits a file
5157 name from a name of a function in that file, as in "break foo.c:bar".
5159 `set demangle-style' completes on available demangling styles.
5161 * New platform-independent commands:
5163 It is now possible to define a post-hook for a command as well as a
5164 hook that runs before the command. For more details, see the
5165 documentation of `hookpost' in the GDB manual.
5167 * Changes in GNU/Linux native debugging.
5169 Support for debugging multi-threaded programs has been completely
5170 revised for all platforms except m68k and sparc. You can now debug as
5171 many threads as your system allows you to have.
5173 Attach/detach is supported for multi-threaded programs.
5175 Support for SSE registers was added for x86. This doesn't work for
5176 multi-threaded programs though.
5178 * Changes in MIPS configurations.
5180 Multi-arch support is enabled for all MIPS configurations.
5182 GDB can now be built as native debugger on SGI Irix 6.x systems for
5183 debugging n32 executables. (Debugging 64-bit executables is not yet
5186 * Unified support for hardware watchpoints in all x86 configurations.
5188 Most (if not all) native x86 configurations support hardware-assisted
5189 breakpoints and watchpoints in a unified manner. This support
5190 implements debug register sharing between watchpoints, which allows to
5191 put a virtually infinite number of watchpoints on the same address,
5192 and also supports watching regions up to 16 bytes with several debug
5195 The new maintenance command `maintenance show-debug-regs' toggles
5196 debugging print-outs in functions that insert, remove, and test
5197 watchpoints and hardware breakpoints.
5199 * Changes in the DJGPP native configuration.
5201 New command ``info dos sysinfo'' displays assorted information about
5202 the CPU, OS, memory, and DPMI server.
5204 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5205 display information about segment descriptors stored in GDT, LDT, and
5208 New commands ``info dos pde'' and ``info dos pte'' display entries
5209 from Page Directory and Page Tables (for now works with CWSDPMI only).
5210 New command ``info dos address-pte'' displays the Page Table entry for
5211 a given linear address.
5213 GDB can now pass command lines longer than 126 characters to the
5214 program being debugged (requires an update to the libdbg.a library
5215 which is part of the DJGPP development kit).
5217 DWARF2 debug info is now supported.
5219 It is now possible to `step' and `next' through calls to `longjmp'.
5221 * Changes in documentation.
5223 All GDB documentation was converted to GFDL, the GNU Free
5224 Documentation License.
5226 Tracepoints-related commands are now fully documented in the GDB
5229 TUI, the Text-mode User Interface, is now documented in the manual.
5231 Tracepoints-related commands are now fully documented in the GDB
5234 The "GDB Internals" manual now has an index. It also includes
5235 documentation of `ui_out' functions, GDB coding standards, x86
5236 hardware watchpoints, and memory region attributes.
5238 * GDB's version number moved to ``version.in''
5240 The Makefile variable VERSION has been replaced by the file
5241 ``version.in''. People creating GDB distributions should update the
5242 contents of this file.
5246 GUD support is now a standard part of the EMACS distribution.
5248 *** Changes in GDB 5.0:
5250 * Improved support for debugging FP programs on x86 targets
5252 Unified and much-improved support for debugging floating-point
5253 programs on all x86 targets. In particular, ``info float'' now
5254 displays the FP registers in the same format on all x86 targets, with
5255 greater level of detail.
5257 * Improvements and bugfixes in hardware-assisted watchpoints
5259 It is now possible to watch array elements, struct members, and
5260 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5261 on x86 targets no longer erroneously trigger when the address is
5264 * Improvements in the native DJGPP version of GDB
5266 The distribution now includes all the scripts and auxiliary files
5267 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5268 machines ``out of the box''.
5270 The DJGPP version can now debug programs that use signals. It is
5271 possible to catch signals that happened in the debuggee, deliver
5272 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5273 would kill the program being debugged.) Programs that hook hardware
5274 interrupts (keyboard, timer, etc.) can also be debugged.
5276 It is now possible to debug DJGPP programs that redirect their
5277 standard handles or switch them to raw (as opposed to cooked) mode, or
5278 even close them. The command ``run < foo > bar'' works as expected,
5279 and ``info terminal'' reports useful information about the debuggee's
5280 terminal, including raw/cooked mode, redirection, etc.
5282 The DJGPP version now uses termios functions for console I/O, which
5283 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5286 DOS-style file names with drive letters are now fully supported by
5289 It is now possible to debug DJGPP programs that switch their working
5290 directory. It is also possible to rerun the debuggee any number of
5291 times without restarting GDB; thus, you can use the same setup,
5292 breakpoints, etc. for many debugging sessions.
5294 * New native configurations
5296 ARM GNU/Linux arm*-*-linux*
5297 PowerPC GNU/Linux powerpc-*-linux*
5301 Motorola MCore mcore-*-*
5302 x86 VxWorks i[3456]86-*-vxworks*
5303 PowerPC VxWorks powerpc-*-vxworks*
5304 TI TMS320C80 tic80-*-*
5306 * OBSOLETE configurations
5308 Altos 3068 m68*-altos-*
5309 Convex c1-*-*, c2-*-*
5311 ARM RISCix arm-*-* (as host)
5314 Configurations that have been declared obsolete will be commented out,
5315 but the code will be left in place. If there is no activity to revive
5316 these configurations before the next release of GDB, the sources will
5317 be permanently REMOVED.
5319 * Gould support removed
5321 Support for the Gould PowerNode and NP1 has been removed.
5323 * New features for SVR4
5325 On SVR4 native platforms (such as Solaris), if you attach to a process
5326 without first loading a symbol file, GDB will now attempt to locate and
5327 load symbols from the running process's executable file.
5329 * Many C++ enhancements
5331 C++ support has been greatly improved. Overload resolution now works properly
5332 in almost all cases. RTTI support is on the way.
5334 * Remote targets can connect to a sub-program
5336 A popen(3) style serial-device has been added. This device starts a
5337 sub-process (such as a stand-alone simulator) and then communicates
5338 with that. The sub-program to run is specified using the syntax
5339 ``|<program> <args>'' vis:
5341 (gdb) set remotedebug 1
5342 (gdb) target extended-remote |mn10300-elf-sim program-args
5344 * MIPS 64 remote protocol
5346 A long standing bug in the mips64 remote protocol where by GDB
5347 expected certain 32 bit registers (ex SR) to be transfered as 32
5348 instead of 64 bits has been fixed.
5350 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5351 added to provide backward compatibility with older versions of GDB.
5353 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5355 The command ``set remotebinarydownload'' command has been replaced by
5356 ``set remote X-packet''. Other commands in ``set remote'' family
5357 include ``set remote P-packet''.
5359 * Breakpoint commands accept ranges.
5361 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5362 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5363 ``tracepoint passcount'' also accepts a range of tracepoints.
5365 * ``apropos'' command added.
5367 The ``apropos'' command searches through command names and
5368 documentation strings, printing out matches, making it much easier to
5369 try to find a command that does what you are looking for.
5373 A new machine oriented interface (MI) has been added to GDB. This
5374 interface is designed for debug environments running GDB as a separate
5375 process. This is part of the long term libGDB project. See the
5376 "GDB/MI" chapter of the GDB manual for further information. It can be
5377 enabled by configuring with:
5379 .../configure --enable-gdbmi
5381 *** Changes in GDB-4.18:
5383 * New native configurations
5385 HP-UX 10.20 hppa*-*-hpux10.20
5386 HP-UX 11.x hppa*-*-hpux11.0*
5387 M68K GNU/Linux m68*-*-linux*
5391 Fujitsu FR30 fr30-*-elf*
5392 Intel StrongARM strongarm-*-*
5393 Mitsubishi D30V d30v-*-*
5395 * OBSOLETE configurations
5397 Gould PowerNode, NP1 np1-*-*, pn-*-*
5399 Configurations that have been declared obsolete will be commented out,
5400 but the code will be left in place. If there is no activity to revive
5401 these configurations before the next release of GDB, the sources will
5402 be permanently REMOVED.
5406 As a compatibility experiment, GDB's source files buildsym.h and
5407 buildsym.c have been converted to pure standard C, no longer
5408 containing any K&R compatibility code. We believe that all systems in
5409 use today either come with a standard C compiler, or have a GCC port
5410 available. If this is not true, please report the affected
5411 configuration to bug-gdb@gnu.org immediately. See the README file for
5412 information about getting a standard C compiler if you don't have one
5417 GDB now uses readline 2.2.
5419 * set extension-language
5421 You can now control the mapping between filename extensions and source
5422 languages by using the `set extension-language' command. For instance,
5423 you can ask GDB to treat .c files as C++ by saying
5424 set extension-language .c c++
5425 The command `info extensions' lists all of the recognized extensions
5426 and their associated languages.
5428 * Setting processor type for PowerPC and RS/6000
5430 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5431 you can use the `set processor' command to specify what variant of the
5432 PowerPC family you are debugging. The command
5436 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5437 following PowerPC and RS6000 variants:
5439 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5440 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5442 403GC IBM PowerPC 403GC
5443 505 Motorola PowerPC 505
5444 860 Motorola PowerPC 860 or 850
5445 601 Motorola PowerPC 601
5446 602 Motorola PowerPC 602
5447 603 Motorola/IBM PowerPC 603 or 603e
5448 604 Motorola PowerPC 604 or 604e
5449 750 Motorola/IBM PowerPC 750 or 750
5451 At the moment, this command just tells GDB what to name the
5452 special-purpose processor registers. Since almost all the affected
5453 registers are inaccessible to user-level programs, this command is
5454 only useful for remote debugging in its present form.
5458 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5459 more extensive support for HP-UX. Added features include shared
5460 library support, kernel threads and hardware watchpoints for 11.00,
5461 support for HP's ANSI C and C++ compilers, and a compatibility mode
5462 for xdb and dbx commands.
5466 HP's donation includes the new concept of catchpoints, which is a
5467 generalization of the old catch command. On HP-UX, it is now possible
5468 to catch exec, fork, and vfork, as well as library loading.
5470 This means that the existing catch command has changed; its first
5471 argument now specifies the type of catch to be set up. See the
5472 output of "help catch" for a list of catchpoint types.
5474 * Debugging across forks
5476 On HP-UX, you can choose which process to debug when a fork() happens
5481 HP has donated a curses-based terminal user interface (TUI). To get
5482 it, build with --enable-tui. Although this can be enabled for any
5483 configuration, at present it only works for native HP debugging.
5485 * GDB remote protocol additions
5487 A new protocol packet 'X' that writes binary data is now available.
5488 Default behavior is to try 'X', then drop back to 'M' if the stub
5489 fails to respond. The settable variable `remotebinarydownload'
5490 allows explicit control over the use of 'X'.
5492 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5493 full 64-bit address. The command
5495 set remoteaddresssize 32
5497 can be used to revert to the old behaviour. For existing remote stubs
5498 the change should not be noticed, as the additional address information
5501 In order to assist in debugging stubs, you may use the maintenance
5502 command `packet' to send any text string to the stub. For instance,
5504 maint packet heythere
5506 sends the packet "$heythere#<checksum>". Note that it is very easy to
5507 disrupt a debugging session by sending the wrong packet at the wrong
5510 The compare-sections command allows you to compare section data on the
5511 target to what is in the executable file without uploading or
5512 downloading, by comparing CRC checksums.
5514 * Tracing can collect general expressions
5516 You may now collect general expressions at tracepoints. This requires
5517 further additions to the target-side stub; see tracepoint.c and
5518 doc/agentexpr.texi for further details.
5520 * mask-address variable for Mips
5522 For Mips targets, you may control the zeroing of the upper 32 bits of
5523 a 64-bit address by entering `set mask-address on'. This is mainly
5524 of interest to users of embedded R4xxx and R5xxx processors.
5526 * Higher serial baud rates
5528 GDB's serial code now allows you to specify baud rates 57600, 115200,
5529 230400, and 460800 baud. (Note that your host system may not be able
5530 to achieve all of these rates.)
5534 The i960 configuration now includes an initial implementation of a
5535 builtin simulator, contributed by Jim Wilson.
5538 *** Changes in GDB-4.17:
5540 * New native configurations
5542 Alpha GNU/Linux alpha*-*-linux*
5543 Unixware 2.x i[3456]86-unixware2*
5544 Irix 6.x mips*-sgi-irix6*
5545 PowerPC GNU/Linux powerpc-*-linux*
5546 PowerPC Solaris powerpcle-*-solaris*
5547 Sparc GNU/Linux sparc-*-linux*
5548 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5552 Argonaut Risc Chip (ARC) arc-*-*
5553 Hitachi H8/300S h8300*-*-*
5554 Matsushita MN10200 w/simulator mn10200-*-*
5555 Matsushita MN10300 w/simulator mn10300-*-*
5556 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5557 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5558 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5559 Mitsubishi D10V w/simulator d10v-*-*
5560 Mitsubishi M32R/D w/simulator m32r-*-elf*
5561 Tsqware Sparclet sparclet-*-*
5562 NEC V850 w/simulator v850-*-*
5564 * New debugging protocols
5566 ARM with RDI protocol arm*-*-*
5567 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5568 DDB and LSI variants of PMON protocol mips*-*-*
5569 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5570 PowerPC with SDS protocol powerpc{,le}-*-eabi
5571 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5575 All configurations can now understand and use the DWARF 2 debugging
5576 format. The choice is automatic, if the symbol file contains DWARF 2
5581 GDB now includes basic Java language support. This support is
5582 only useful with Java compilers that produce native machine code.
5584 * solib-absolute-prefix and solib-search-path
5586 For SunOS and SVR4 shared libraries, you may now set the prefix for
5587 loading absolute shared library symbol files, and the search path for
5588 locating non-absolute shared library symbol files.
5590 * Live range splitting
5592 GDB can now effectively debug code for which GCC has performed live
5593 range splitting as part of its optimization. See gdb/doc/LRS for
5594 more details on the expected format of the stabs information.
5598 GDB's support for the GNU Hurd, including thread debugging, has been
5599 updated to work with current versions of the Hurd.
5603 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5604 instruction set. ARM GDB automatically detects when Thumb
5605 instructions are in use, and adjusts disassembly and backtracing
5610 GDB's MIPS target configurations now handle the MIP16 16-bit
5615 GDB now includes support for overlays; if an executable has been
5616 linked such that multiple sections are based at the same address, GDB
5617 will decide which section to use for symbolic info. You can choose to
5618 control the decision manually, using overlay commands, or implement
5619 additional target-side support and use "overlay load-target" to bring
5620 in the overlay mapping. Do "help overlay" for more detail.
5624 The command "info symbol <address>" displays information about
5625 the symbol at the specified address.
5629 The standard remote protocol now includes an extension that allows
5630 asynchronous collection and display of trace data. This requires
5631 extensive support in the target-side debugging stub. Tracing mode
5632 includes a new interaction mode in GDB and new commands: see the
5633 file tracepoint.c for more details.
5637 Configurations for embedded MIPS now include a simulator contributed
5638 by Cygnus Solutions. The simulator supports the instruction sets
5639 of most MIPS variants.
5643 Sparc configurations may now include the ERC32 simulator contributed
5644 by the European Space Agency. The simulator is not built into
5645 Sparc targets by default; configure with --enable-sim to include it.
5649 For target configurations that may include multiple variants of a
5650 basic architecture (such as MIPS and SH), you may now set the
5651 architecture explicitly. "set arch" sets, "info arch" lists
5652 the possible architectures.
5654 *** Changes in GDB-4.16:
5656 * New native configurations
5658 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5659 M68K NetBSD m68k-*-netbsd*
5660 PowerPC AIX 4.x powerpc-*-aix*
5661 PowerPC MacOS powerpc-*-macos*
5662 PowerPC Windows NT powerpcle-*-cygwin32
5663 RS/6000 AIX 4.x rs6000-*-aix4*
5667 ARM with RDP protocol arm-*-*
5668 I960 with MON960 i960-*-coff
5669 MIPS VxWorks mips*-*-vxworks*
5670 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5671 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5673 Matra Sparclet sparclet-*-*
5677 The powerpc-eabi configuration now includes the PSIM simulator,
5678 contributed by Andrew Cagney, with assistance from Mike Meissner.
5679 PSIM is a very elaborate model of the PowerPC, including not only
5680 basic instruction set execution, but also details of execution unit
5681 performance and I/O hardware. See sim/ppc/README for more details.
5685 GDB now works with Solaris 2.5.
5687 * Windows 95/NT native
5689 GDB will now work as a native debugger on Windows 95 and Windows NT.
5690 To build it from source, you must use the "gnu-win32" environment,
5691 which uses a DLL to emulate enough of Unix to run the GNU tools.
5692 Further information, binaries, and sources are available at
5693 ftp.cygnus.com, under pub/gnu-win32.
5695 * dont-repeat command
5697 If a user-defined command includes the command `dont-repeat', then the
5698 command will not be repeated if the user just types return. This is
5699 useful if the command is time-consuming to run, so that accidental
5700 extra keystrokes don't run the same command many times.
5702 * Send break instead of ^C
5704 The standard remote protocol now includes an option to send a break
5705 rather than a ^C to the target in order to interrupt it. By default,
5706 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5708 * Remote protocol timeout
5710 The standard remote protocol includes a new variable `remotetimeout'
5711 that allows you to set the number of seconds before GDB gives up trying
5712 to read from the target. The default value is 2.
5714 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5716 By default GDB will automatically keep track of objects as they are
5717 loaded and unloaded by the dynamic linker. By using the command `set
5718 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5719 when shared library events occur, thus allowing you to set breakpoints
5720 in shared libraries which are explicitly loaded by the inferior.
5722 Note this feature does not work on hpux8. On hpux9 you must link
5723 /usr/lib/end.o into your program. This feature should work
5724 automatically on hpux10.
5726 * Irix 5.x hardware watchpoint support
5728 Irix 5 configurations now support the use of hardware watchpoints.
5730 * Mips protocol "SYN garbage limit"
5732 When debugging a Mips target using the `target mips' protocol, you
5733 may set the number of characters that GDB will ignore by setting
5734 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5735 every character. The default value is 1050.
5737 * Recording and replaying remote debug sessions
5739 If you set `remotelogfile' to the name of a file, gdb will write to it
5740 a recording of a remote debug session. This recording may then be
5741 replayed back to gdb using "gdbreplay". See gdbserver/README for
5742 details. This is useful when you have a problem with GDB while doing
5743 remote debugging; you can make a recording of the session and send it
5744 to someone else, who can then recreate the problem.
5746 * Speedups for remote debugging
5748 GDB includes speedups for downloading and stepping MIPS systems using
5749 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5750 and more efficient S-record downloading.
5752 * Memory use reductions and statistics collection
5754 GDB now uses less memory and reports statistics about memory usage.
5755 Try the `maint print statistics' command, for example.
5757 *** Changes in GDB-4.15:
5759 * Psymtabs for XCOFF
5761 The symbol reader for AIX GDB now uses partial symbol tables. This
5762 can greatly improve startup time, especially for large executables.
5764 * Remote targets use caching
5766 Remote targets now use a data cache to speed up communication with the
5767 remote side. The data cache could lead to incorrect results because
5768 it doesn't know about volatile variables, thus making it impossible to
5769 debug targets which use memory mapped I/O devices. `set remotecache
5770 off' turns the the data cache off.
5772 * Remote targets may have threads
5774 The standard remote protocol now includes support for multiple threads
5775 in the target system, using new protocol commands 'H' and 'T'. See
5776 gdb/remote.c for details.
5780 If GDB is configured with `--enable-netrom', then it will include
5781 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5782 acts as though it is a bank of ROM on the target board, but you can
5783 write into it over the network. GDB's support consists only of
5784 support for fast loading into the emulated ROM; to debug, you must use
5785 another protocol, such as standard remote protocol. The usual
5786 sequence is something like
5788 target nrom <netrom-hostname>
5790 target remote <netrom-hostname>:1235
5794 GDB now includes support for the Apple Macintosh, as a host only. It
5795 may be run as either an MPW tool or as a standalone application, and
5796 it can debug through the serial port. All the usual GDB commands are
5797 available, but to the target command, you must supply "serial" as the
5798 device type instead of "/dev/ttyXX". See mpw-README in the main
5799 directory for more information on how to build. The MPW configuration
5800 scripts */mpw-config.in support only a few targets, and only the
5801 mips-idt-ecoff target has been tested.
5805 GDB configuration now uses autoconf. This is not user-visible,
5806 but does simplify configuration and building.
5810 GDB now supports hpux10.
5812 *** Changes in GDB-4.14:
5814 * New native configurations
5816 x86 FreeBSD i[345]86-*-freebsd
5817 x86 NetBSD i[345]86-*-netbsd
5818 NS32k NetBSD ns32k-*-netbsd
5819 Sparc NetBSD sparc-*-netbsd
5823 A29K VxWorks a29k-*-vxworks
5824 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5825 CPU32 EST-300 emulator m68*-*-est*
5826 PowerPC ELF powerpc-*-elf
5829 * Alpha OSF/1 support for procfs
5831 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5832 possible to attach to running processes. As the mounting of the /proc
5833 filesystem is optional on the Alpha, GDB automatically determines
5834 the availability of /proc during startup. This can lead to problems
5835 if /proc is unmounted after GDB has been started.
5837 * Arguments to user-defined commands
5839 User commands may accept up to 10 arguments separated by whitespace.
5840 Arguments are accessed within the user command via $arg0..$arg9. A
5843 print $arg0 + $arg1 + $arg2
5845 To execute the command use:
5848 Defines the command "adder" which prints the sum of its three arguments.
5849 Note the arguments are text substitutions, so they may reference variables,
5850 use complex expressions, or even perform inferior function calls.
5852 * New `if' and `while' commands
5854 This makes it possible to write more sophisticated user-defined
5855 commands. Both commands take a single argument, which is the
5856 expression to evaluate, and must be followed by the commands to
5857 execute, one per line, if the expression is nonzero, the list being
5858 terminated by the word `end'. The `if' command list may include an
5859 `else' word, which causes the following commands to be executed only
5860 if the expression is zero.
5862 * Fortran source language mode
5864 GDB now includes partial support for Fortran 77. It will recognize
5865 Fortran programs and can evaluate a subset of Fortran expressions, but
5866 variables and functions may not be handled correctly. GDB will work
5867 with G77, but does not yet know much about symbols emitted by other
5870 * Better HPUX support
5872 Most debugging facilities now work on dynamic executables for HPPAs
5873 running hpux9 or later. You can attach to running dynamically linked
5874 processes, but by default the dynamic libraries will be read-only, so
5875 for instance you won't be able to put breakpoints in them. To change
5876 that behavior do the following before running the program:
5882 This will cause the libraries to be mapped private and read-write.
5883 To revert to the normal behavior, do this:
5889 You cannot set breakpoints or examine data in the library until after
5890 the library is loaded if the function/data symbols do not have
5893 GDB can now also read debug symbols produced by the HP C compiler on
5894 HPPAs (sorry, no C++, Fortran or 68k support).
5896 * Target byte order now dynamically selectable
5898 You can choose which byte order to use with a target system, via the
5899 commands "set endian big" and "set endian little", and you can see the
5900 current setting by using "show endian". You can also give the command
5901 "set endian auto", in which case GDB will use the byte order
5902 associated with the executable. Currently, only embedded MIPS
5903 configurations support dynamic selection of target byte order.
5905 * New DOS host serial code
5907 This version uses DPMI interrupts to handle buffered I/O, so you
5908 no longer need to run asynctsr when debugging boards connected to
5911 *** Changes in GDB-4.13:
5913 * New "complete" command
5915 This lists all the possible completions for the rest of the line, if it
5916 were to be given as a command itself. This is intended for use by emacs.
5918 * Trailing space optional in prompt
5920 "set prompt" no longer adds a space for you after the prompt you set. This
5921 allows you to set a prompt which ends in a space or one that does not.
5923 * Breakpoint hit counts
5925 "info break" now displays a count of the number of times the breakpoint
5926 has been hit. This is especially useful in conjunction with "ignore"; you
5927 can ignore a large number of breakpoint hits, look at the breakpoint info
5928 to see how many times the breakpoint was hit, then run again, ignoring one
5929 less than that number, and this will get you quickly to the last hit of
5932 * Ability to stop printing at NULL character
5934 "set print null-stop" will cause GDB to stop printing the characters of
5935 an array when the first NULL is encountered. This is useful when large
5936 arrays actually contain only short strings.
5938 * Shared library breakpoints
5940 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5941 breakpoints in shared libraries before the executable is run.
5943 * Hardware watchpoints
5945 There is a new hardware breakpoint for the watch command for sparclite
5946 targets. See gdb/sparclite/hw_breakpoint.note.
5948 Hardware watchpoints are also now supported under GNU/Linux.
5952 Annotations have been added. These are for use with graphical interfaces,
5953 and are still experimental. Currently only gdba.el uses these.
5955 * Improved Irix 5 support
5957 GDB now works properly with Irix 5.2.
5959 * Improved HPPA support
5961 GDB now works properly with the latest GCC and GAS.
5963 * New native configurations
5965 Sequent PTX4 i[34]86-sequent-ptx4
5966 HPPA running OSF/1 hppa*-*-osf*
5967 Atari TT running SVR4 m68*-*-sysv4*
5968 RS/6000 LynxOS rs6000-*-lynxos*
5972 OS/9000 i[34]86-*-os9k
5973 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5976 * Hitachi SH7000 and E7000-PC ICE support
5978 There is now support for communicating with the Hitachi E7000-PC ICE.
5979 This is available automatically when GDB is configured for the SH.
5983 As usual, a variety of small fixes and improvements, both generic
5984 and configuration-specific. See the ChangeLog for more detail.
5986 *** Changes in GDB-4.12:
5988 * Irix 5 is now supported
5992 GDB-4.12 on the HPPA has a number of changes which make it unable
5993 to debug the output from the currently released versions of GCC and
5994 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5995 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5996 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5999 *** Changes in GDB-4.11:
6001 * User visible changes:
6005 The "set remotedebug" option is now consistent between the mips remote
6006 target, remote targets using the gdb-specific protocol, UDI (AMD's
6007 debug protocol for the 29k) and the 88k bug monitor. It is now an
6008 integer specifying a debug level (normally 0 or 1, but 2 means more
6009 debugging info for the mips target).
6011 * DEC Alpha native support
6013 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6014 debug info, but GDB works fairly well with the DEC compiler and should
6015 work with a future GCC release. See the README file for a few
6016 Alpha-specific notes.
6018 * Preliminary thread implementation
6020 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6022 * LynxOS native and target support for 386
6024 This release has been hosted on LynxOS 2.2, and also can be configured
6025 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6028 * Improvements in C++ mangling/demangling.
6030 This release has much better g++ debugging, specifically in name
6031 mangling/demangling, virtual function calls, print virtual table,
6032 call methods, ...etc.
6034 *** Changes in GDB-4.10:
6036 * User visible changes:
6038 Remote debugging using the GDB-specific (`target remote') protocol now
6039 supports the `load' command. This is only useful if you have some
6040 other way of getting the stub to the target system, and you can put it
6041 somewhere in memory where it won't get clobbered by the download.
6043 Filename completion now works.
6045 When run under emacs mode, the "info line" command now causes the
6046 arrow to point to the line specified. Also, "info line" prints
6047 addresses in symbolic form (as well as hex).
6049 All vxworks based targets now support a user settable option, called
6050 vxworks-timeout. This option represents the number of seconds gdb
6051 should wait for responses to rpc's. You might want to use this if
6052 your vxworks target is, perhaps, a slow software simulator or happens
6053 to be on the far side of a thin network line.
6057 This release contains support for using a DEC alpha as a GDB host for
6058 cross debugging. Native alpha debugging is not supported yet.
6061 *** Changes in GDB-4.9:
6065 This is the first GDB release which is accompanied by a matching testsuite.
6066 The testsuite requires installation of dejagnu, which should be available
6067 via ftp from most sites that carry GNU software.
6071 'Cfront' style demangling has had its name changed to 'ARM' style, to
6072 emphasize that it was written from the specifications in the C++ Annotated
6073 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6074 disclaimers, it still generated too much confusion with users attempting to
6075 use gdb with AT&T cfront.
6079 GDB now uses a standard remote interface to a simulator library.
6080 So far, the library contains simulators for the Zilog Z8001/2, the
6081 Hitachi H8/300, H8/500 and Super-H.
6083 * New targets supported
6085 H8/300 simulator h8300-hitachi-hms or h8300hms
6086 H8/500 simulator h8500-hitachi-hms or h8500hms
6087 SH simulator sh-hitachi-hms or sh
6088 Z8000 simulator z8k-zilog-none or z8ksim
6089 IDT MIPS board over serial line mips-idt-ecoff
6091 Cross-debugging to GO32 targets is supported. It requires a custom
6092 version of the i386-stub.c module which is integrated with the
6093 GO32 memory extender.
6095 * New remote protocols
6097 MIPS remote debugging protocol.
6099 * New source languages supported
6101 This version includes preliminary support for Chill, a Pascal like language
6102 used by telecommunications companies. Chill support is also being integrated
6103 into the GNU compiler, but we don't know when it will be publically available.
6106 *** Changes in GDB-4.8:
6108 * HP Precision Architecture supported
6110 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6111 version of this support was available as a set of patches from the
6112 University of Utah. GDB does not support debugging of programs
6113 compiled with the HP compiler, because HP will not document their file
6114 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6115 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6117 Many problems in the preliminary version have been fixed.
6119 * Faster and better demangling
6121 We have improved template demangling and fixed numerous bugs in the GNU style
6122 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6123 character types (wchar_t) are now supported. Demangling of each symbol is now
6124 only done once, and is cached when the symbol table for a file is read in.
6125 This results in a small increase in memory usage for C programs, a moderate
6126 increase in memory usage for C++ programs, and a fantastic speedup in
6129 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6130 from the specifications in the Annotated Reference Manual, which AT&T's
6131 compiler does not actually implement.
6133 * G++ multiple inheritance compiler problem
6135 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6136 inheritance lattices was reworked to properly discover ambiguities. We
6137 recently found an example which causes this new algorithm to fail in a
6138 very subtle way, producing bad debug information for those classes.
6139 The file 'gcc.patch' (in this directory) can be applied to gcc to
6140 circumvent the problem. A future GCC release will contain a complete
6143 The previous G++ debug info problem (mentioned below for the gdb-4.7
6144 release) is fixed in gcc version 2.3.2.
6146 * Improved configure script
6148 The `configure' script will now attempt to guess your system type if
6149 you don't supply a host system type. The old scheme of supplying a
6150 host system triplet is preferable over using this. All the magic is
6151 done in the new `config.guess' script. Examine it for details.
6153 We have also brought our configure script much more in line with the FSF's
6154 version. It now supports the --with-xxx options. In particular,
6155 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6156 The resulting GDB will not be able to read arbitrary object file formats --
6157 only the format ``expected'' to be used on the configured target system.
6158 We hope to make this the default in a future release.
6160 * Documentation improvements
6162 There's new internal documentation on how to modify GDB, and how to
6163 produce clean changes to the code. We implore people to read it
6164 before submitting changes.
6166 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6167 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6168 `info' files are also provided. To build `info' files from scratch,
6169 you will need the latest `makeinfo' release, which will be available in
6170 a future texinfo-X.Y release.
6172 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6173 We're not sure exactly which versions have this problem, but it has
6174 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6175 or better. If that isn't possible, there is a patch in
6176 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6177 around this problem.
6181 GDB now supports array constants that can be used in expressions typed in by
6182 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6183 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6186 The new directory `gdb/sparclite' contains a program that demonstrates
6187 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6189 * New native hosts supported
6191 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6192 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6194 * New targets supported
6196 AMD 29k family via UDI a29k-amd-udi or udi29k
6198 * New file formats supported
6200 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6201 HPUX core files, and SCO 3.2v2 core files.
6205 Attaching to processes now works again; thanks for the many bug reports.
6207 We have also stomped on a bunch of core dumps caused by
6208 printf_filtered("%s") problems.
6210 We eliminated a copyright problem on the rpc and ptrace header files
6211 for VxWorks, which was discovered at the last minute during the 4.7
6212 release. You should now be able to build a VxWorks GDB.
6214 You can now interrupt gdb while an attached process is running. This
6215 will cause the attached process to stop, and give control back to GDB.
6217 We fixed problems caused by using too many file descriptors
6218 for reading symbols from object files and libraries. This was
6219 especially a problem for programs that used many (~100) shared
6222 The `step' command now only enters a subroutine if there is line number
6223 information for the subroutine. Otherwise it acts like the `next'
6224 command. Previously, `step' would enter subroutines if there was
6225 any debugging information about the routine. This avoids problems
6226 when using `cc -g1' on MIPS machines.
6228 * Internal improvements
6230 GDB's internal interfaces have been improved to make it easier to support
6231 debugging of multiple languages in the future.
6233 GDB now uses a common structure for symbol information internally.
6234 Minimal symbols (derived from linkage symbols in object files), partial
6235 symbols (from a quick scan of debug information), and full symbols
6236 contain a common subset of information, making it easier to write
6237 shared code that handles any of them.
6239 * New command line options
6241 We now accept --silent as an alias for --quiet.
6245 The memory-mapped-malloc library is now licensed under the GNU Library
6246 General Public License.
6248 *** Changes in GDB-4.7:
6250 * Host/native/target split
6252 GDB has had some major internal surgery to untangle the support for
6253 hosts and remote targets. Now, when you configure GDB for a remote
6254 target, it will no longer load in all of the support for debugging
6255 local programs on the host. When fully completed and tested, this will
6256 ensure that arbitrary host/target combinations are possible.
6258 The primary conceptual shift is to separate the non-portable code in
6259 GDB into three categories. Host specific code is required any time GDB
6260 is compiled on that host, regardless of the target. Target specific
6261 code relates to the peculiarities of the target, but can be compiled on
6262 any host. Native specific code is everything else: it can only be
6263 built when the host and target are the same system. Child process
6264 handling and core file support are two common `native' examples.
6266 GDB's use of /proc for controlling Unix child processes is now cleaner.
6267 It has been split out into a single module under the `target_ops' vector,
6268 plus two native-dependent functions for each system that uses /proc.
6270 * New hosts supported
6272 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6273 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6274 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6276 * New targets supported
6278 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6279 68030 and CPU32 m68030-*-*, m68332-*-*
6281 * New native hosts supported
6283 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6284 (386bsd is not well tested yet)
6285 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6287 * New file formats supported
6289 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6290 supports reading of `a.out.adobe' object files, which are an a.out
6291 format extended with minimal information about multiple sections.
6295 `show copying' is the same as the old `info copying'.
6296 `show warranty' is the same as `info warrantee'.
6297 These were renamed for consistency. The old commands continue to work.
6299 `info handle' is a new alias for `info signals'.
6301 You can now define pre-command hooks, which attach arbitrary command
6302 scripts to any command. The commands in the hook will be executed
6303 prior to the user's command. You can also create a hook which will be
6304 executed whenever the program stops. See gdb.texinfo.
6308 We now deal with Cfront style name mangling, and can even extract type
6309 info from mangled symbols. GDB can automatically figure out which
6310 symbol mangling style your C++ compiler uses.
6312 Calling of methods and virtual functions has been improved as well.
6316 The crash that occured when debugging Sun Ansi-C compiled binaries is
6317 fixed. This was due to mishandling of the extra N_SO stabs output
6320 We also finally got Ultrix 4.2 running in house, and fixed core file
6321 support, with help from a dozen people on the net.
6323 John M. Farrell discovered that the reason that single-stepping was so
6324 slow on all of the Mips based platforms (primarily SGI and DEC) was
6325 that we were trying to demangle and lookup a symbol used for internal
6326 purposes on every instruction that was being stepped through. Changing
6327 the name of that symbol so that it couldn't be mistaken for a C++
6328 mangled symbol sped things up a great deal.
6330 Rich Pixley sped up symbol lookups in general by getting much smarter
6331 about when C++ symbol mangling is necessary. This should make symbol
6332 completion (TAB on the command line) much faster. It's not as fast as
6333 we'd like, but it's significantly faster than gdb-4.6.
6337 A new user controllable variable 'call_scratch_address' can
6338 specify the location of a scratch area to be used when GDB
6339 calls a function in the target. This is necessary because the
6340 usual method of putting the scratch area on the stack does not work
6341 in systems that have separate instruction and data spaces.
6343 We integrated changes to support the 29k UDI (Universal Debugger
6344 Interface), but discovered at the last minute that we didn't have all
6345 of the appropriate copyright paperwork. We are working with AMD to
6346 resolve this, and hope to have it available soon.
6350 We have sped up the remote serial line protocol, especially for targets
6351 with lots of registers. It now supports a new `expedited status' ('T')
6352 message which can be used in place of the existing 'S' status message.
6353 This allows the remote stub to send only the registers that GDB
6354 needs to make a quick decision about single-stepping or conditional
6355 breakpoints, eliminating the need to fetch the entire register set for
6356 each instruction being stepped through.
6358 The GDB remote serial protocol now implements a write-through cache for
6359 registers, only re-reading the registers if the target has run.
6361 There is also a new remote serial stub for SPARC processors. You can
6362 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6363 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6364 processor with a serial port.
6368 Configure.in files have become much easier to read and modify. A new
6369 `table driven' format makes it more obvious what configurations are
6370 supported, and what files each one uses.
6374 There is a new opcodes library which will eventually contain all of the
6375 disassembly routines and opcode tables. At present, it only contains
6376 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6377 disassembler (binutils/objdump) to share these routines.
6379 The libiberty library is now copylefted under the GNU Library General
6380 Public License. This allows more liberal use, and was done so libg++
6381 can use it. This makes no difference to GDB, since the Library License
6382 grants all the rights from the General Public License.
6386 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6387 reference to the stabs symbol info used by the debugger. It is (as far
6388 as we know) the only published document on this fascinating topic. We
6389 encourage you to read it, compare it to the stabs information on your
6390 system, and send improvements on the document in general (to
6391 bug-gdb@prep.ai.mit.edu).
6393 And, of course, many bugs have been fixed.
6396 *** Changes in GDB-4.6:
6398 * Better support for C++ function names
6400 GDB now accepts as input the "demangled form" of C++ overloaded function
6401 names and member function names, and can do command completion on such names
6402 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6403 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6404 Make use of command completion, it is your friend.
6406 GDB also now accepts a variety of C++ mangled symbol formats. They are
6407 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6408 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6409 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6410 for the list of formats.
6412 * G++ symbol mangling problem
6414 Recent versions of gcc have a bug in how they emit debugging information for
6415 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6416 directory) can be applied to gcc to fix the problem. Alternatively, if you
6417 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6418 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6419 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6422 * New 'maintenance' command
6424 All of the commands related to hacking GDB internals have been moved out of
6425 the main command set, and now live behind the 'maintenance' command. This
6426 can also be abbreviated as 'mt'. The following changes were made:
6428 dump-me -> maintenance dump-me
6429 info all-breakpoints -> maintenance info breakpoints
6430 printmsyms -> maintenance print msyms
6431 printobjfiles -> maintenance print objfiles
6432 printpsyms -> maintenance print psymbols
6433 printsyms -> maintenance print symbols
6435 The following commands are new:
6437 maintenance demangle Call internal GDB demangler routine to
6438 demangle a C++ link name and prints the result.
6439 maintenance print type Print a type chain for a given symbol
6441 * Change to .gdbinit file processing
6443 We now read the $HOME/.gdbinit file before processing the argv arguments
6444 (e.g. reading symbol files or core files). This allows global parameters to
6445 be set, which will apply during the symbol reading. The ./.gdbinit is still
6446 read after argv processing.
6448 * New hosts supported
6450 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6452 GNU/Linux support i386-unknown-linux or linux
6454 We are also including code to support the HP/PA running BSD and HPUX. This
6455 is almost guaranteed not to work, as we didn't have time to test or build it
6456 for this release. We are including it so that the more adventurous (or
6457 masochistic) of you can play with it. We also had major problems with the
6458 fact that the compiler that we got from HP doesn't support the -g option.
6461 * New targets supported
6463 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6465 * More smarts about finding #include files
6467 GDB now remembers the compilation directory for all include files, and for
6468 all files from which C is generated (like yacc and lex sources). This
6469 greatly improves GDB's ability to find yacc/lex sources, and include files,
6470 especially if you are debugging your program from a directory different from
6471 the one that contains your sources.
6473 We also fixed a bug which caused difficulty with listing and setting
6474 breakpoints in include files which contain C code. (In the past, you had to
6475 try twice in order to list an include file that you hadn't looked at before.)
6477 * Interesting infernals change
6479 GDB now deals with arbitrary numbers of sections, where the symbols for each
6480 section must be relocated relative to that section's landing place in the
6481 target's address space. This work was needed to support ELF with embedded
6482 stabs used by Solaris-2.0.
6484 * Bug fixes (of course!)
6486 There have been loads of fixes for the following things:
6487 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6488 i960, stabs, DOS(GO32), procfs, etc...
6490 See the ChangeLog for details.
6492 *** Changes in GDB-4.5:
6494 * New machines supported (host and target)
6496 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6498 SGI Irix-4.x mips-sgi-irix4 or iris4
6500 * New malloc package
6502 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6503 Mmalloc is capable of handling mutiple heaps of memory. It is also
6504 capable of saving a heap to a file, and then mapping it back in later.
6505 This can be used to greatly speedup the startup of GDB by using a
6506 pre-parsed symbol table which lives in a mmalloc managed heap. For
6507 more details, please read mmalloc/mmalloc.texi.
6511 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6512 'help info proc' for details.
6514 * MIPS ecoff symbol table format
6516 The code that reads MIPS symbol table format is now supported on all hosts.
6517 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6520 * File name changes for MS-DOS
6522 Many files in the config directories have been renamed to make it easier to
6523 support GDB on MS-DOSe systems (which have very restrictive file name
6524 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6525 environment) is close to working but has some remaining problems. Note
6526 that debugging of DOS programs is not supported, due to limitations
6527 in the ``operating system'', but it can be used to host cross-debugging.
6529 * Cross byte order fixes
6531 Many fixes have been made to support cross debugging of Sparc and MIPS
6532 targets from hosts whose byte order differs.
6534 * New -mapped and -readnow options
6536 If memory-mapped files are available on your system through the 'mmap'
6537 system call, you can use the -mapped option on the `file' or
6538 `symbol-file' commands to cause GDB to write the symbols from your
6539 program into a reusable file. If the program you are debugging is
6540 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6541 Future GDB debugging sessions will notice the presence of this file,
6542 and will quickly map in symbol information from it, rather than reading
6543 the symbol table from the executable program. Using the '-mapped'
6544 option in a GDB `file' or `symbol-file' command has the same effect as
6545 starting GDB with the '-mapped' command-line option.
6547 You can cause GDB to read the entire symbol table immediately by using
6548 the '-readnow' option with any of the commands that load symbol table
6549 information (or on the GDB command line). This makes the command
6550 slower, but makes future operations faster.
6552 The -mapped and -readnow options are typically combined in order to
6553 build a `fred.syms' file that contains complete symbol information.
6554 A simple GDB invocation to do nothing but build a `.syms' file for future
6557 gdb -batch -nx -mapped -readnow programname
6559 The `.syms' file is specific to the host machine on which GDB is run.
6560 It holds an exact image of GDB's internal symbol table. It cannot be
6561 shared across multiple host platforms.
6563 * longjmp() handling
6565 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6566 siglongjmp() without losing control. This feature has not yet been ported to
6567 all systems. It currently works on many 386 platforms, all MIPS-based
6568 platforms (SGI, DECstation, etc), and Sun3/4.
6572 Preliminary work has been put in to support the new Solaris OS from Sun. At
6573 this time, it can control and debug processes, but it is not capable of
6578 As always, many many bug fixes. The major areas were with g++, and mipsread.
6579 People using the MIPS-based platforms should experience fewer mysterious
6580 crashes and trashed symbol tables.
6582 *** Changes in GDB-4.4:
6584 * New machines supported (host and target)
6586 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6588 BSD Reno on Vax vax-dec-bsd
6589 Ultrix on Vax vax-dec-ultrix
6591 * New machines supported (target)
6593 AMD 29000 embedded, using EBMON a29k-none-none
6597 GDB continues to improve its handling of C++. `References' work better.
6598 The demangler has also been improved, and now deals with symbols mangled as
6599 per the Annotated C++ Reference Guide.
6601 GDB also now handles `stabs' symbol information embedded in MIPS
6602 `ecoff' symbol tables. Since the ecoff format was not easily
6603 extensible to handle new languages such as C++, this appeared to be a
6604 good way to put C++ debugging info into MIPS binaries. This option
6605 will be supported in the GNU C compiler, version 2, when it is
6608 * New features for SVR4
6610 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6611 shared libraries. Debugging dynamically linked programs should present
6612 only minor differences from debugging statically linked programs.
6614 The `info proc' command will print out information about any process
6615 on an SVR4 system (including the one you are debugging). At the moment,
6616 it prints the address mappings of the process.
6618 If you bring up GDB on another SVR4 system, please send mail to
6619 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6621 * Better dynamic linking support in SunOS
6623 Reading symbols from shared libraries which contain debugging symbols
6624 now works properly. However, there remain issues such as automatic
6625 skipping of `transfer vector' code during function calls, which
6626 make it harder to debug code in a shared library, than to debug the
6627 same code linked statically.
6631 GDB is now using the latest `getopt' routines from the FSF. This
6632 version accepts the -- prefix for options with long names. GDB will
6633 continue to accept the old forms (-option and +option) as well.
6634 Various single letter abbreviations for options have been explicity
6635 added to the option table so that they won't get overshadowed in the
6636 future by other options that begin with the same letter.
6640 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6641 Many assorted bugs have been handled. Many more remain to be handled.
6642 See the various ChangeLog files (primarily in gdb and bfd) for details.
6645 *** Changes in GDB-4.3:
6647 * New machines supported (host and target)
6649 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6650 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6651 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6653 * Almost SCO Unix support
6655 We had hoped to support:
6656 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6657 (except for core file support), but we discovered very late in the release
6658 that it has problems with process groups that render gdb unusable. Sorry
6659 about that. I encourage people to fix it and post the fixes.
6661 * Preliminary ELF and DWARF support
6663 GDB can read ELF object files on System V Release 4, and can handle
6664 debugging records for C, in DWARF format, in ELF files. This support
6665 is preliminary. If you bring up GDB on another SVR4 system, please
6666 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6671 GDB now uses the latest `readline' library. One user-visible change
6672 is that two tabs will list possible command completions, which previously
6673 required typing M-? (meta-question mark, or ESC ?).
6677 The `stepi' bug that many of you noticed has been squashed.
6678 Many bugs in C++ have been handled. Many more remain to be handled.
6679 See the various ChangeLog files (primarily in gdb and bfd) for details.
6681 * State of the MIPS world (in case you wondered):
6683 GDB can understand the symbol tables emitted by the compilers
6684 supplied by most vendors of MIPS-based machines, including DEC. These
6685 symbol tables are in a format that essentially nobody else uses.
6687 Some versions of gcc come with an assembler post-processor called
6688 mips-tfile. This program is required if you want to do source-level
6689 debugging of gcc-compiled programs. I believe FSF does not ship
6690 mips-tfile with gcc version 1, but it will eventually come with gcc
6693 Debugging of g++ output remains a problem. g++ version 1.xx does not
6694 really support it at all. (If you're lucky, you should be able to get
6695 line numbers and stack traces to work, but no parameters or local
6696 variables.) With some work it should be possible to improve the
6699 When gcc version 2 is released, you will have somewhat better luck.
6700 However, even then you will get confusing results for inheritance and
6703 We will eventually provide full debugging of g++ output on
6704 DECstations. This will probably involve some kind of stabs-in-ecoff
6705 encapulation, but the details have not been worked out yet.
6708 *** Changes in GDB-4.2:
6710 * Improved configuration
6712 Only one copy of `configure' exists now, and it is not self-modifying.
6713 Porting BFD is simpler.
6717 The `step' and `next' commands now only stop at the first instruction
6718 of a source line. This prevents the multiple stops that used to occur
6719 in switch statements, for-loops, etc. `Step' continues to stop if a
6720 function that has debugging information is called within the line.
6724 Lots of small bugs fixed. More remain.
6726 * New host supported (not target)
6728 Intel 386 PC clone running Mach i386-none-mach
6731 *** Changes in GDB-4.1:
6733 * Multiple source language support
6735 GDB now has internal scaffolding to handle several source languages.
6736 It determines the type of each source file from its filename extension,
6737 and will switch expression parsing and number formatting to match the
6738 language of the function in the currently selected stack frame.
6739 You can also specifically set the language to be used, with
6740 `set language c' or `set language modula-2'.
6744 GDB now has preliminary support for the GNU Modula-2 compiler,
6745 currently under development at the State University of New York at
6746 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6747 continue through the fall of 1991 and into 1992.
6749 Other Modula-2 compilers are currently not supported, and attempting to
6750 debug programs compiled with them will likely result in an error as the
6751 symbol table is read. Feel free to work on it, though!
6753 There are hooks in GDB for strict type checking and range checking,
6754 in the `Modula-2 philosophy', but they do not currently work.
6758 GDB can now write to executable and core files (e.g. patch
6759 a variable's value). You must turn this switch on, specify
6760 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6761 by assigning a new value to a variable. Modifications take
6764 * Automatic SunOS shared library reading
6766 When you run your program, GDB automatically determines where its
6767 shared libraries (if any) have been loaded, and reads their symbols.
6768 The `share' command is no longer needed. This also works when
6769 examining core files.
6773 You can specify the number of lines that the `list' command shows.
6776 * New machines supported (host and target)
6778 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6779 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6780 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6782 * New hosts supported (not targets)
6784 IBM RT/PC: romp-ibm-aix or rtpc
6786 * New targets supported (not hosts)
6788 AMD 29000 embedded with COFF a29k-none-coff
6789 AMD 29000 embedded with a.out a29k-none-aout
6790 Ultracomputer remote kernel debug a29k-nyu-kern
6792 * New remote interfaces
6798 *** Changes in GDB-4.0:
6802 Wide output is wrapped at good places to make the output more readable.
6804 Gdb now supports cross-debugging from a host machine of one type to a
6805 target machine of another type. Communication with the target system
6806 is over serial lines. The ``target'' command handles connecting to the
6807 remote system; the ``load'' command will download a program into the
6808 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6809 also supports debugging of realtime processes running under VxWorks,
6810 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6811 stub on the target system.
6813 New CPUs supported include the AMD 29000 and Intel 960.
6815 GDB now reads object files and symbol tables via a ``binary file''
6816 library, which allows a single copy of GDB to debug programs of multiple
6817 object file types such as a.out and coff.
6819 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6820 refcard.dvi and refcard.ps are available to format it).
6823 * Control-Variable user interface simplified
6825 All variables that control the operation of the debugger can be set
6826 by the ``set'' command, and displayed by the ``show'' command.
6828 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6829 ``Show prompt'' produces the response:
6830 Gdb's prompt is new-gdb=>.
6832 What follows are the NEW set commands. The command ``help set'' will
6833 print a complete list of old and new set commands. ``help set FOO''
6834 will give a longer description of the variable FOO. ``show'' will show
6835 all of the variable descriptions and their current settings.
6837 confirm on/off: Enables warning questions for operations that are
6838 hard to recover from, e.g. rerunning the program while
6839 it is already running. Default is ON.
6841 editing on/off: Enables EMACS style command line editing
6842 of input. Previous lines can be recalled with
6843 control-P, the current line can be edited with control-B,
6844 you can search for commands with control-R, etc.
6847 history filename NAME: NAME is where the gdb command history
6848 will be stored. The default is .gdb_history,
6849 or the value of the environment variable
6852 history size N: The size, in commands, of the command history. The
6853 default is 256, or the value of the environment variable
6856 history save on/off: If this value is set to ON, the history file will
6857 be saved after exiting gdb. If set to OFF, the
6858 file will not be saved. The default is OFF.
6860 history expansion on/off: If this value is set to ON, then csh-like
6861 history expansion will be performed on
6862 command line input. The default is OFF.
6864 radix N: Sets the default radix for input and output. It can be set
6865 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6866 in the current radix, so "set radix 10" is always a no-op.
6868 height N: This integer value is the number of lines on a page. Default
6869 is 24, the current `stty rows'' setting, or the ``li#''
6870 setting from the termcap entry matching the environment
6873 width N: This integer value is the number of characters on a line.
6874 Default is 80, the current `stty cols'' setting, or the ``co#''
6875 setting from the termcap entry matching the environment
6878 Note: ``set screensize'' is obsolete. Use ``set height'' and
6879 ``set width'' instead.
6881 print address on/off: Print memory addresses in various command displays,
6882 such as stack traces and structure values. Gdb looks
6883 more ``symbolic'' if you turn this off; it looks more
6884 ``machine level'' with it on. Default is ON.
6886 print array on/off: Prettyprint arrays. New convenient format! Default
6889 print demangle on/off: Print C++ symbols in "source" form if on,
6892 print asm-demangle on/off: Same, for assembler level printouts
6895 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6898 * Support for Epoch Environment.
6900 The epoch environment is a version of Emacs v18 with windowing. One
6901 new command, ``inspect'', is identical to ``print'', except that if you
6902 are running in the epoch environment, the value is printed in its own
6906 * Support for Shared Libraries
6908 GDB can now debug programs and core files that use SunOS shared libraries.
6909 Symbols from a shared library cannot be referenced
6910 before the shared library has been linked with the program (this
6911 happens after you type ``run'' and before the function main() is entered).
6912 At any time after this linking (including when examining core files
6913 from dynamically linked programs), gdb reads the symbols from each
6914 shared library when you type the ``sharedlibrary'' command.
6915 It can be abbreviated ``share''.
6917 sharedlibrary REGEXP: Load shared object library symbols for files
6918 matching a unix regular expression. No argument
6919 indicates to load symbols for all shared libraries.
6921 info sharedlibrary: Status of loaded shared libraries.
6926 A watchpoint stops execution of a program whenever the value of an
6927 expression changes. Checking for this slows down execution
6928 tremendously whenever you are in the scope of the expression, but is
6929 quite useful for catching tough ``bit-spreader'' or pointer misuse
6930 problems. Some machines such as the 386 have hardware for doing this
6931 more quickly, and future versions of gdb will use this hardware.
6933 watch EXP: Set a watchpoint (breakpoint) for an expression.
6935 info watchpoints: Information about your watchpoints.
6937 delete N: Deletes watchpoint number N (same as breakpoints).
6938 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6939 enable N: Re-enables watchpoint number N (same as breakpoints).
6942 * C++ multiple inheritance
6944 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6947 * C++ exception handling
6949 Gdb now supports limited C++ exception handling. Besides the existing
6950 ability to breakpoint on an exception handler, gdb can breakpoint on
6951 the raising of an exception (before the stack is peeled back to the
6954 catch FOO: If there is a FOO exception handler in the dynamic scope,
6955 set a breakpoint to catch exceptions which may be raised there.
6956 Multiple exceptions (``catch foo bar baz'') may be caught.
6958 info catch: Lists all exceptions which may be caught in the
6959 current stack frame.
6962 * Minor command changes
6964 The command ``call func (arg, arg, ...)'' now acts like the print
6965 command, except it does not print or save a value if the function's result
6966 is void. This is similar to dbx usage.
6968 The ``up'' and ``down'' commands now always print the frame they end up
6969 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6970 frames without printing.
6972 * New directory command
6974 'dir' now adds directories to the FRONT of the source search path.
6975 The path starts off empty. Source files that contain debug information
6976 about the directory in which they were compiled can be found even
6977 with an empty path; Sun CC and GCC include this information. If GDB can't
6978 find your source file in the current directory, type "dir .".
6980 * Configuring GDB for compilation
6982 For normal use, type ``./configure host''. See README or gdb.texinfo
6985 GDB now handles cross debugging. If you are remotely debugging between
6986 two different machines, type ``./configure host -target=targ''.
6987 Host is the machine where GDB will run; targ is the machine
6988 where the program that you are debugging will run.