1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.0
6 * The 'ptype' command now accepts a '/o' flag, which prints the
7 offsets and sizes of fields in a struct, like the pahole(1) tool.
9 * New "--readnever" command line option instructs GDB to not read each
10 symbol file's symbolic debug information. This makes startup faster
11 but at the expense of not being able to perform symbolic debugging.
12 This option is intended for use cases where symbolic debugging will
13 not be used, e.g., when you only need to dump the debuggee's core.
15 * GDB now uses the GNU MPFR library, if available, to emulate target
16 floating-point arithmetic during expression evaluation when the target
17 uses different floating-point formats than the host. At least version
18 3.1 of GNU MPFR is required.
20 * GDB now supports access to the guarded-storage-control registers and the
21 software-based guarded-storage broadcast control registers on IBM z14.
23 * On Unix systems, GDB now supports transmitting environment variables
24 that are to be set or unset to GDBserver. These variables will
25 affect the environment to be passed to the remote inferior.
27 To inform GDB of environment variables that are to be transmitted to
28 GDBserver, use the "set environment" command. Only user set
29 environment variables are sent to GDBserver.
31 To inform GDB of environment variables that are to be unset before
32 the remote inferior is started by the GDBserver, use the "unset
35 * Completion improvements
37 ** GDB can now complete function parameters in linespecs and
38 explicit locations without quoting. When setting breakpoints,
39 quoting around functions names to help with TAB-completion is
40 generally no longer necessary. For example, this now completes
43 (gdb) b function(in[TAB]
46 Related, GDB is no longer confused with completing functions in
47 C++ anonymous namespaces:
50 (gdb) b (anonymous namespace)::[TAB][TAB]
51 (anonymous namespace)::a_function()
52 (anonymous namespace)::b_function()
54 ** GDB now has much improved linespec and explicit locations TAB
55 completion support, that better understands what you're
56 completing and offers better suggestions. For example, GDB no
57 longer offers data symbols as possible completions when you're
60 ** GDB now TAB-completes label symbol names.
62 ** The "complete" command now mimics TAB completion accurately.
64 * New command line options (gcore)
67 Dump all memory mappings.
69 * Breakpoints on C++ functions are now set on all scopes by default
71 By default, breakpoints on functions/methods are now interpreted as
72 specifying all functions with the given name ignoring missing
73 leading scopes (namespaces and classes).
75 For example, assuming a C++ program with symbols named:
80 both commands "break func()" and "break B::func()" set a breakpoint
83 You can use the new flag "-qualified" to override this. This makes
84 GDB interpret the specified function name as a complete
85 fully-qualified name instead. For example, using the same C++
86 program, the "break -q B::func" command sets a breakpoint on
87 "B::func", only. A parameter has been added to the Python
88 gdb.Breakpoint constructor to achieve the same result when creating
89 a breakpoint from Python.
91 * Breakpoints on functions marked with C++ ABI tags
93 GDB can now set breakpoints on functions marked with C++ ABI tags
94 (e.g., [abi:cxx11]). See here for a description of ABI tags:
95 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
97 Functions with a C++11 abi tag are demangled/displayed like this:
99 function[abi:cxx11](int)
102 You can now set a breakpoint on such functions simply as if they had
105 (gdb) b function(int)
107 Or if you need to disambiguate between tags, like:
109 (gdb) b function[abi:other_tag](int)
111 Tab completion was adjusted accordingly as well.
115 ** New events gdb.new_inferior, gdb.inferior_deleted, and
116 gdb.new_thread are emitted. See the manual for further
117 description of these.
119 ** A new command, "rbreak" has been added to the Python API. This
120 command allows the setting of a large number of breakpoints via a
121 regex pattern in Python. See the manual for further details.
123 ** Python breakpoints can now accept explicit locations. See the
124 manual for a further description of this feature.
127 * New features in the GDB remote stub, GDBserver
129 ** GDBserver is now able to start inferior processes with a
130 specified initial working directory.
132 The user can set the desired working directory to be used from
133 GDB using the new "set cwd" command.
135 ** New "--selftest" command line option runs some GDBserver self
136 tests. These self tests are disabled in releases.
138 ** On Unix systems, GDBserver now does globbing expansion and variable
139 substitution in inferior command line arguments.
141 This is done by starting inferiors using a shell, like GDB does.
142 See "set startup-with-shell" in the user manual for how to disable
143 this from GDB when using "target extended-remote". When using
144 "target remote", you can disable the startup with shell by using the
145 new "--no-startup-with-shell" GDBserver command line option.
147 ** On Unix systems, GDBserver now supports receiving environment
148 variables that are to be set or unset from GDB. These variables
149 will affect the environment to be passed to the inferior.
151 * When catching an Ada exception raised with a message, GDB now prints
152 the message in the catchpoint hit notification. In GDB/MI mode, that
153 information is provided as an extra field named "exception-message"
154 in the *stopped notification.
156 * Trait objects can now be inspected When debugging Rust code. This
157 requires compiler support which will appear in Rust 1.24.
161 QEnvironmentHexEncoded
162 Inform GDBserver of an environment variable that is to be passed to
163 the inferior when starting it.
166 Inform GDBserver of an environment variable that is to be unset
167 before starting the remote inferior.
170 Inform GDBserver that the environment should be reset (i.e.,
171 user-set environment variables should be unset).
174 Indicates whether the inferior must be started with a shell or not.
177 Tell GDBserver that the inferior to be started should use a specific
180 * The "maintenance print c-tdesc" command now takes an optional
181 argument which is the file name of XML target description.
183 * The "maintenance selftest" command now takes an optional argument to
184 filter the tests to be run.
186 * The "enable", and "disable" commands now accept a range of
187 breakpoint locations, e.g. "enable 1.3-5".
192 Set and show the current working directory for the inferior.
195 Set and show compilation command used for compiling and injecting code
196 with the 'compile' commands.
198 set debug separate-debug-file
199 show debug separate-debug-file
200 Control the display of debug output about separate debug file search.
202 set dump-excluded-mappings
203 show dump-excluded-mappings
204 Control whether mappings marked with the VM_DONTDUMP flag should be
205 dumped when generating a core file.
208 List the registered selftests.
211 Start the debugged program stopping at the first instruction.
214 Control display of debugging messages related to OpenRISC targets.
216 set|show print type nested-type-limit
217 Set and show the limit of nesting level for nested types that the
218 type printer will show.
220 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
223 * Safer/improved support for debugging with no debug info
225 GDB no longer assumes functions with no debug information return
228 This means that GDB now refuses to call such functions unless you
229 tell it the function's type, by either casting the call to the
230 declared return type, or by casting the function to a function
231 pointer of the right type, and calling that:
233 (gdb) p getenv ("PATH")
234 'getenv' has unknown return type; cast the call to its declared return type
235 (gdb) p (char *) getenv ("PATH")
236 $1 = 0x7fffffffe "/usr/local/bin:/"...
237 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
238 $2 = 0x7fffffffe "/usr/local/bin:/"...
240 Similarly, GDB no longer assumes that global variables with no debug
241 info have type 'int', and refuses to print the variable's value
242 unless you tell it the variable's type:
245 'var' has unknown type; cast it to its declared type
249 * New native configurations
251 FreeBSD/aarch64 aarch64*-*-freebsd*
252 FreeBSD/arm arm*-*-freebsd*
256 FreeBSD/aarch64 aarch64*-*-freebsd*
257 FreeBSD/arm arm*-*-freebsd*
258 OpenRISC ELF or1k*-*-elf
260 * Removed targets and native configurations
262 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
264 *** Changes in GDB 8.0
266 * GDB now supports access to the PKU register on GNU/Linux. The register is
267 added by the Memory Protection Keys for Userspace feature which will be
268 available in future Intel CPUs.
270 * GDB now supports C++11 rvalue references.
274 ** New functions to start, stop and access a running btrace recording.
275 ** Rvalue references are now supported in gdb.Type.
277 * GDB now supports recording and replaying rdrand and rdseed Intel 64
280 * Building GDB and GDBserver now requires a C++11 compiler.
282 For example, GCC 4.8 or later.
284 It is no longer possible to build GDB or GDBserver with a C
285 compiler. The --disable-build-with-cxx configure option has been
288 * Building GDB and GDBserver now requires GNU make >= 3.81.
290 It is no longer supported to build GDB or GDBserver with another
291 implementation of the make program or an earlier version of GNU make.
293 * Native debugging on MS-Windows supports command-line redirection
295 Command-line arguments used for starting programs on MS-Windows can
296 now include redirection symbols supported by native Windows shells,
297 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
298 as "run", "start", and "set args", as well as the corresponding MI
301 * Support for thread names on MS-Windows.
303 GDB now catches and handles the special exception that programs
304 running on MS-Windows use to assign names to threads in the
307 * Support for Java programs compiled with gcj has been removed.
309 * User commands now accept an unlimited number of arguments.
310 Previously, only up to 10 was accepted.
312 * The "eval" command now expands user-defined command arguments.
314 This makes it easier to process a variable number of arguments:
319 eval "print $arg%d", $i
324 * Target descriptions can now describe registers for sparc32 and sparc64.
326 * GDB now supports DWARF version 5 (debug information format).
327 Its .debug_names index is not yet supported.
329 * New native configurations
331 FreeBSD/mips mips*-*-freebsd
335 Synopsys ARC arc*-*-elf32
336 FreeBSD/mips mips*-*-freebsd
338 * Removed targets and native configurations
340 Alpha running FreeBSD alpha*-*-freebsd*
341 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
346 Erases all the flash memory regions reported by the target.
348 maint print arc arc-instruction address
349 Print internal disassembler information about instruction at a given address.
353 set disassembler-options
354 show disassembler-options
355 Controls the passing of target specific information to the disassembler.
356 If it is necessary to specify more than one disassembler option then
357 multiple options can be placed together into a comma separated list.
358 The default value is the empty string. Currently, the only supported
359 targets are ARM, PowerPC and S/390.
364 Erases all the flash memory regions reported by the target. This is
365 equivalent to the CLI command flash-erase.
367 -file-list-shared-libraries
368 List the shared libraries in the program. This is
369 equivalent to the CLI command "info shared".
371 *** Changes in GDB 7.12
373 * GDB and GDBserver now build with a C++ compiler by default.
375 The --enable-build-with-cxx configure option is now enabled by
376 default. One must now explicitly configure with
377 --disable-build-with-cxx in order to build with a C compiler. This
378 option will be removed in a future release.
380 * GDBserver now supports recording btrace without maintaining an active
383 * GDB now supports a negative repeat count in the 'x' command to examine
384 memory backward from the given address. For example:
387 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
388 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
389 (gdb) x/-5i 0x0000000000400580
390 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
391 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
392 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
393 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
394 0x40057b <main(int, char**)+25>:
395 callq 0x400536 <Func1(int, char const*)>
397 * Fortran: Support structures with fields of dynamic types and
398 arrays of dynamic types.
400 * The symbol dumping maintenance commands have new syntax.
401 maint print symbols [-pc address] [--] [filename]
402 maint print symbols [-objfile objfile] [-source source] [--] [filename]
403 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
404 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
405 maint print msymbols [-objfile objfile] [--] [filename]
407 * GDB now supports multibit bitfields and enums in target register
410 * New Python-based convenience function $_as_string(val), which returns
411 the textual representation of a value. This function is especially
412 useful to obtain the text label of an enum value.
414 * Intel MPX bound violation handling.
416 Segmentation faults caused by a Intel MPX boundary violation
417 now display the kind of violation (upper or lower), the memory
418 address accessed and the memory bounds, along with the usual
419 signal received and code location.
423 Program received signal SIGSEGV, Segmentation fault
424 Upper bound violation while accessing address 0x7fffffffc3b3
425 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
426 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
428 * Rust language support.
429 GDB now supports debugging programs written in the Rust programming
430 language. See https://www.rust-lang.org/ for more information about
433 * Support for running interpreters on specified input/output devices
435 GDB now supports a new mechanism that allows frontends to provide
436 fully featured GDB console views, as a better alternative to
437 building such views on top of the "-interpreter-exec console"
438 command. See the new "new-ui" command below. With that command,
439 frontends can now start GDB in the traditional command-line mode
440 running in an embedded terminal emulator widget, and create a
441 separate MI interpreter running on a specified i/o device. In this
442 way, GDB handles line editing, history, tab completion, etc. in the
443 console all by itself, and the GUI uses the separate MI interpreter
444 for its own control and synchronization, invisible to the command
447 * The "catch syscall" command catches groups of related syscalls.
449 The "catch syscall" command now supports catching a group of related
450 syscalls using the 'group:' or 'g:' prefix.
455 skip -gfile file-glob-pattern
456 skip -function function
457 skip -rfunction regular-expression
458 A generalized form of the skip command, with new support for
459 glob-style file names and regular expressions for function names.
460 Additionally, a file spec and a function spec may now be combined.
462 maint info line-table REGEXP
463 Display the contents of GDB's internal line table data struture.
466 Run any GDB unit tests that were compiled in.
469 Start a new user interface instance running INTERP as interpreter,
470 using the TTY file for input/output.
474 ** gdb.Breakpoint objects have a new attribute "pending", which
475 indicates whether the breakpoint is pending.
476 ** Three new breakpoint-related events have been added:
477 gdb.breakpoint_created, gdb.breakpoint_modified, and
478 gdb.breakpoint_deleted.
481 Signal ("set") the given MS-Windows event object. This is used in
482 conjunction with the Windows JIT debugging (AeDebug) support, where
483 the OS suspends a crashing process until a debugger can attach to
484 it. Resuming the crashing process, in order to debug it, is done by
487 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
488 was added in GDBserver, including JIT compiling fast tracepoint's
489 conditional expression bytecode into native code.
491 * Support for various remote target protocols and ROM monitors has
494 target m32rsdi Remote M32R debugging over SDI
495 target mips MIPS remote debugging protocol
496 target pmon PMON ROM monitor
497 target ddb NEC's DDB variant of PMON for Vr4300
498 target rockhopper NEC RockHopper variant of PMON
499 target lsi LSI variant of PMO
501 * Support for tracepoints and fast tracepoints on powerpc-linux,
502 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
503 including JIT compiling fast tracepoint's conditional expression
504 bytecode into native code.
506 * MI async record =record-started now includes the method and format used for
507 recording. For example:
509 =record-started,thread-group="i1",method="btrace",format="bts"
511 * MI async record =thread-selected now includes the frame field. For example:
513 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
517 Andes NDS32 nds32*-*-elf
519 *** Changes in GDB 7.11
521 * GDB now supports debugging kernel-based threads on FreeBSD.
523 * Per-inferior thread numbers
525 Thread numbers are now per inferior instead of global. If you're
526 debugging multiple inferiors, GDB displays thread IDs using a
527 qualified INF_NUM.THR_NUM form. For example:
531 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
532 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
533 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
534 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
536 As consequence, thread numbers as visible in the $_thread
537 convenience variable and in Python's InferiorThread.num attribute
538 are no longer unique between inferiors.
540 GDB now maintains a second thread ID per thread, referred to as the
541 global thread ID, which is the new equivalent of thread numbers in
542 previous releases. See also $_gthread below.
544 For backwards compatibility, MI's thread IDs always refer to global
547 * Commands that accept thread IDs now accept the qualified
548 INF_NUM.THR_NUM form as well. For example:
551 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
554 * In commands that accept a list of thread IDs, you can now refer to
555 all threads of an inferior using a star wildcard. GDB accepts
556 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
557 refer to all threads of the current inferior. For example, "info
560 * You can use "info threads -gid" to display the global thread ID of
563 * The new convenience variable $_gthread holds the global number of
566 * The new convenience variable $_inferior holds the number of the
569 * GDB now displays the ID and name of the thread that hit a breakpoint
570 or received a signal, if your program is multi-threaded. For
573 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
574 Thread 1 "main" received signal SIGINT, Interrupt.
576 * Record btrace now supports non-stop mode.
578 * Support for tracepoints on aarch64-linux was added in GDBserver.
580 * The 'record instruction-history' command now indicates speculative execution
581 when using the Intel Processor Trace recording format.
583 * GDB now allows users to specify explicit locations, bypassing
584 the linespec parser. This feature is also available to GDB/MI
587 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
588 GDB now is able to debug both AArch64 applications and ARM applications
591 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
592 including JIT compiling fast tracepoint's conditional expression bytecode
595 * GDB now supports displaced stepping on AArch64 GNU/Linux.
597 * "info threads", "info inferiors", "info display", "info checkpoints"
598 and "maint info program-spaces" now list the corresponding items in
599 ascending ID order, for consistency with all other "info" commands.
601 * In Ada, the overloads selection menu has been enhanced to display the
602 parameter types and the return types for the matching overloaded subprograms.
606 maint set target-non-stop (on|off|auto)
607 maint show target-non-stop
608 Control whether GDB targets always operate in non-stop mode even if
609 "set non-stop" is "off". The default is "auto", meaning non-stop
610 mode is enabled if supported by the target.
612 maint set bfd-sharing
613 maint show bfd-sharing
614 Control the reuse of bfd objects.
618 Control display of debugging info regarding bfd caching.
622 Control display of debugging info regarding FreeBSD threads.
624 set remote multiprocess-extensions-packet
625 show remote multiprocess-extensions-packet
626 Set/show the use of the remote protocol multiprocess extensions.
628 set remote thread-events
629 show remote thread-events
630 Set/show the use of thread create/exit events.
632 set ada print-signatures on|off
633 show ada print-signatures"
634 Control whether parameter types and return types are displayed in overloads
635 selection menus. It is activaled (@code{on}) by default.
639 Controls the maximum size of memory, in bytes, that GDB will
640 allocate for value contents. Prevents incorrect programs from
641 causing GDB to allocate overly large buffers. Default is 64k.
643 * The "disassemble" command accepts a new modifier: /s.
644 It prints mixed source+disassembly like /m with two differences:
645 - disassembled instructions are now printed in program order, and
646 - and source for all relevant files is now printed.
647 The "/m" option is now considered deprecated: its "source-centric"
648 output hasn't proved useful in practice.
650 * The "record instruction-history" command accepts a new modifier: /s.
651 It behaves exactly like /m and prints mixed source+disassembly.
653 * The "set scheduler-locking" command supports a new mode "replay".
654 It behaves like "off" in record mode and like "on" in replay mode.
656 * Support for various ROM monitors has been removed:
658 target dbug dBUG ROM monitor for Motorola ColdFire
659 target picobug Motorola picobug monitor
660 target dink32 DINK32 ROM monitor for PowerPC
661 target m32r Renesas M32R/D ROM monitor
662 target mon2000 mon2000 ROM monitor
663 target ppcbug PPCBUG ROM monitor for PowerPC
665 * Support for reading/writing memory and extracting values on architectures
666 whose memory is addressable in units of any integral multiple of 8 bits.
671 Indicates that an exec system call was executed.
673 exec-events feature in qSupported
674 The qSupported packet allows GDB to request support for exec
675 events using the new 'gdbfeature' exec-event, and the qSupported
676 response can contain the corresponding 'stubfeature'. Set and
677 show commands can be used to display whether these features are enabled.
680 Equivalent to interrupting with the ^C character, but works in
683 thread created stop reason (T05 create:...)
684 Indicates that the thread was just created and is stopped at entry.
686 thread exit stop reply (w exitcode;tid)
687 Indicates that the thread has terminated.
690 Enables/disables thread create and exit event reporting. For
691 example, this is used in non-stop mode when GDB stops a set of
692 threads and synchronously waits for the their corresponding stop
693 replies. Without exit events, if one of the threads exits, GDB
694 would hang forever not knowing that it should no longer expect a
695 stop for that same thread.
698 Indicates that there are no resumed threads left in the target (all
699 threads are stopped). The remote stub reports support for this stop
700 reply to GDB's qSupported query.
703 Enables/disables catching syscalls from the inferior process.
704 The remote stub reports support for this packet to GDB's qSupported query.
706 syscall_entry stop reason
707 Indicates that a syscall was just called.
709 syscall_return stop reason
710 Indicates that a syscall just returned.
712 * Extended-remote exec events
714 ** GDB now has support for exec events on extended-remote Linux targets.
715 For such targets with Linux kernels 2.5.46 and later, this enables
716 follow-exec-mode and exec catchpoints.
718 set remote exec-event-feature-packet
719 show remote exec-event-feature-packet
720 Set/show the use of the remote exec event feature.
722 * Thread names in remote protocol
724 The reply to qXfer:threads:read may now include a name attribute for each
727 * Target remote mode fork and exec events
729 ** GDB now has support for fork and exec events on target remote mode
730 Linux targets. For such targets with Linux kernels 2.5.46 and later,
731 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
732 fork and exec catchpoints.
734 * Remote syscall events
736 ** GDB now has support for catch syscall on remote Linux targets,
737 currently enabled on x86/x86_64 architectures.
739 set remote catch-syscall-packet
740 show remote catch-syscall-packet
741 Set/show the use of the remote catch syscall feature.
745 ** The -var-set-format command now accepts the zero-hexadecimal
746 format. It outputs data in hexadecimal format with zero-padding on the
751 ** gdb.InferiorThread objects have a new attribute "global_num",
752 which refers to the thread's global thread ID. The existing
753 "num" attribute now refers to the thread's per-inferior number.
754 See "Per-inferior thread numbers" above.
755 ** gdb.InferiorThread objects have a new attribute "inferior", which
756 is the Inferior object the thread belongs to.
758 *** Changes in GDB 7.10
760 * Support for process record-replay and reverse debugging on aarch64*-linux*
761 targets has been added. GDB now supports recording of A64 instruction set
762 including advance SIMD instructions.
764 * Support for Sun's version of the "stabs" debug file format has been removed.
766 * GDB now honors the content of the file /proc/PID/coredump_filter
767 (PID is the process ID) on GNU/Linux systems. This file can be used
768 to specify the types of memory mappings that will be included in a
769 corefile. For more information, please refer to the manual page of
770 "core(5)". GDB also has a new command: "set use-coredump-filter
771 on|off". It allows to set whether GDB will read the content of the
772 /proc/PID/coredump_filter file when generating a corefile.
774 * The "info os" command on GNU/Linux can now display information on
776 "info os cpus" Listing of all cpus/cores on the system
778 * GDB has two new commands: "set serial parity odd|even|none" and
779 "show serial parity". These allows to set or show parity for the
782 * The "info source" command now displays the producer string if it was
783 present in the debug info. This typically includes the compiler version
784 and may include things like its command line arguments.
786 * The "info dll", an alias of the "info sharedlibrary" command,
787 is now available on all platforms.
789 * Directory names supplied to the "set sysroot" commands may be
790 prefixed with "target:" to tell GDB to access shared libraries from
791 the target system, be it local or remote. This replaces the prefix
792 "remote:". The default sysroot has been changed from "" to
793 "target:". "remote:" is automatically converted to "target:" for
794 backward compatibility.
796 * The system root specified by "set sysroot" will be prepended to the
797 filename of the main executable (if reported to GDB as absolute by
798 the operating system) when starting processes remotely, and when
799 attaching to already-running local or remote processes.
801 * GDB now supports automatic location and retrieval of executable
802 files from remote targets. Remote debugging can now be initiated
803 using only a "target remote" or "target extended-remote" command
804 (no "set sysroot" or "file" commands are required). See "New remote
807 * The "dump" command now supports verilog hex format.
809 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
811 * On GNU/Linux, GDB and gdbserver are now able to access executable
812 and shared library files without a "set sysroot" command when
813 attaching to processes running in different mount namespaces from
814 the debugger. This makes it possible to attach to processes in
815 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
816 See "New remote packets" below.
818 * The "tui reg" command now provides completion for all of the
819 available register groups, including target specific groups.
821 * The HISTSIZE environment variable is no longer read when determining
822 the size of GDB's command history. GDB now instead reads the dedicated
823 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
824 disables truncation of command history. Non-numeric values of GDBHISTSIZE
829 ** Memory ports can now be unbuffered.
833 ** gdb.Objfile objects have a new attribute "username",
834 which is the name of the objfile as specified by the user,
835 without, for example, resolving symlinks.
836 ** You can now write frame unwinders in Python.
837 ** gdb.Type objects have a new method "optimized_out",
838 returning optimized out gdb.Value instance of this type.
839 ** gdb.Value objects have new methods "reference_value" and
840 "const_value" which return a reference to the value and a
841 "const" version of the value respectively.
845 maint print symbol-cache
846 Print the contents of the symbol cache.
848 maint print symbol-cache-statistics
849 Print statistics of symbol cache usage.
851 maint flush-symbol-cache
852 Flush the contents of the symbol cache.
856 Start branch trace recording using Branch Trace Store (BTS) format.
859 Evaluate expression by using the compiler and print result.
863 Explicit commands for enabling and disabling tui mode.
866 set mpx bound on i386 and amd64
867 Support for bound table investigation on Intel MPX enabled applications.
871 Start branch trace recording using Intel Processor Trace format.
874 Print information about branch tracing internals.
876 maint btrace packet-history
877 Print the raw branch tracing data.
879 maint btrace clear-packet-history
880 Discard the stored raw branch tracing data.
883 Discard all branch tracing data. It will be fetched and processed
884 anew by the next "record" command.
889 Renamed from "set debug dwarf2-die".
891 Renamed from "show debug dwarf2-die".
894 Renamed from "set debug dwarf2-read".
895 show debug dwarf-read
896 Renamed from "show debug dwarf2-read".
898 maint set dwarf always-disassemble
899 Renamed from "maint set dwarf2 always-disassemble".
900 maint show dwarf always-disassemble
901 Renamed from "maint show dwarf2 always-disassemble".
903 maint set dwarf max-cache-age
904 Renamed from "maint set dwarf2 max-cache-age".
905 maint show dwarf max-cache-age
906 Renamed from "maint show dwarf2 max-cache-age".
909 show debug dwarf-line
910 Control display of debugging info regarding DWARF line processing.
914 Set the maximum number of candidates to be considered during
915 completion. The default value is 200. This limit allows GDB
916 to avoid generating large completion lists, the computation of
917 which can cause the debugger to become temporarily unresponsive.
919 set history remove-duplicates
920 show history remove-duplicates
921 Control the removal of duplicate history entries.
923 maint set symbol-cache-size
924 maint show symbol-cache-size
925 Control the size of the symbol cache.
927 set|show record btrace bts buffer-size
928 Set and show the size of the ring buffer used for branch tracing in
930 The obtained size may differ from the requested size. Use "info
931 record" to see the obtained buffer size.
933 set debug linux-namespaces
934 show debug linux-namespaces
935 Control display of debugging info regarding Linux namespaces.
937 set|show record btrace pt buffer-size
938 Set and show the size of the ring buffer used for branch tracing in
939 Intel Processor Trace format.
940 The obtained size may differ from the requested size. Use "info
941 record" to see the obtained buffer size.
943 maint set|show btrace pt skip-pad
944 Set and show whether PAD packets are skipped when computing the
947 * The command 'thread apply all' can now support new option '-ascending'
948 to call its specified command for all threads in ascending order.
950 * Python/Guile scripting
952 ** GDB now supports auto-loading of Python/Guile scripts contained in the
953 special section named `.debug_gdb_scripts'.
957 qXfer:btrace-conf:read
958 Return the branch trace configuration for the current thread.
960 Qbtrace-conf:bts:size
961 Set the requested ring buffer size for branch tracing in BTS format.
964 Enable Intel Procesor Trace-based branch tracing for the current
965 process. The remote stub reports support for this packet to GDB's
969 Set the requested ring buffer size for branch tracing in Intel Processor
973 Indicates a memory breakpoint instruction was executed, irrespective
974 of whether it was GDB that planted the breakpoint or the breakpoint
975 is hardcoded in the program. This is required for correct non-stop
979 Indicates the target stopped for a hardware breakpoint. This is
980 required for correct non-stop mode operation.
983 Return information about files on the remote system.
986 Return the full absolute name of the file that was executed to
987 create a process running on the remote system.
990 Select the filesystem on which vFile: operations with filename
991 arguments will operate. This is required for GDB to be able to
992 access files on remote targets where the remote stub does not
993 share a common filesystem with the inferior(s).
996 Indicates that a fork system call was executed.
999 Indicates that a vfork system call was executed.
1001 vforkdone stop reason
1002 Indicates that a vfork child of the specified process has executed
1003 an exec or exit, allowing the vfork parent to resume execution.
1005 fork-events and vfork-events features in qSupported
1006 The qSupported packet allows GDB to request support for fork and
1007 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1008 and the qSupported response can contain the corresponding
1009 'stubfeatures'. Set and show commands can be used to display
1010 whether these features are enabled.
1012 * Extended-remote fork events
1014 ** GDB now has support for fork events on extended-remote Linux
1015 targets. For targets with Linux kernels 2.5.60 and later, this
1016 enables follow-fork-mode and detach-on-fork for both fork and
1017 vfork, as well as fork and vfork catchpoints.
1019 * The info record command now shows the recording format and the
1020 branch tracing configuration for the current thread when using
1021 the btrace record target.
1022 For the BTS format, it shows the ring buffer size.
1024 * GDB now has support for DTrace USDT (Userland Static Defined
1025 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1027 * GDB now supports access to vector registers on S/390 GNU/Linux
1030 * Removed command line options
1032 -xdb HP-UX XDB compatibility mode.
1034 * Removed targets and native configurations
1036 HP/PA running HP-UX hppa*-*-hpux*
1037 Itanium running HP-UX ia64-*-hpux*
1039 * New configure options
1042 This configure option allows the user to build GDB with support for
1043 Intel Processor Trace (default: auto). This requires libipt.
1045 --with-libipt-prefix=PATH
1046 Specify the path to the version of libipt that GDB should use.
1047 $PATH/include should contain the intel-pt.h header and
1048 $PATH/lib should contain the libipt.so library.
1050 *** Changes in GDB 7.9.1
1054 ** Xmethods can now specify a result type.
1056 *** Changes in GDB 7.9
1058 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1062 ** You can now access frame registers from Python scripts.
1063 ** New attribute 'producer' for gdb.Symtab objects.
1064 ** gdb.Objfile objects have a new attribute "progspace",
1065 which is the gdb.Progspace object of the containing program space.
1066 ** gdb.Objfile objects have a new attribute "owner".
1067 ** gdb.Objfile objects have a new attribute "build_id",
1068 which is the build ID generated when the file was built.
1069 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1070 ** A new event "gdb.clear_objfiles" has been added, triggered when
1071 selecting a new file to debug.
1072 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1073 ** New function gdb.lookup_objfile.
1075 New events which are triggered when GDB modifies the state of the
1078 ** gdb.events.inferior_call_pre: Function call is about to be made.
1079 ** gdb.events.inferior_call_post: Function call has just been made.
1080 ** gdb.events.memory_changed: A memory location has been altered.
1081 ** gdb.events.register_changed: A register has been altered.
1083 * New Python-based convenience functions:
1085 ** $_caller_is(name [, number_of_frames])
1086 ** $_caller_matches(regexp [, number_of_frames])
1087 ** $_any_caller_is(name [, number_of_frames])
1088 ** $_any_caller_matches(regexp [, number_of_frames])
1090 * GDB now supports the compilation and injection of source code into
1091 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1092 to compile the source code to object code, and if successful, inject
1093 and execute that code within the current context of the inferior.
1094 Currently the C language is supported. The commands used to
1095 interface with this new feature are:
1097 compile code [-raw|-r] [--] [source code]
1098 compile file [-raw|-r] filename
1102 demangle [-l language] [--] name
1103 Demangle "name" in the specified language, or the current language
1104 if elided. This command is renamed from the "maint demangle" command.
1105 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1106 as "maint demangler-warning".
1108 queue-signal signal-name-or-number
1109 Queue a signal to be delivered to the thread when it is resumed.
1111 add-auto-load-scripts-directory directory
1112 Add entries to the list of directories from which to load auto-loaded
1115 maint print user-registers
1116 List all currently available "user" registers.
1118 compile code [-r|-raw] [--] [source code]
1119 Compile, inject, and execute in the inferior the executable object
1120 code produced by compiling the provided source code.
1122 compile file [-r|-raw] filename
1123 Compile and inject into the inferior the executable object code
1124 produced by compiling the source code stored in the filename
1127 * On resume, GDB now always passes the signal the program had stopped
1128 for to the thread the signal was sent to, even if the user changed
1129 threads before resuming. Previously GDB would often (but not
1130 always) deliver the signal to the thread that happens to be current
1133 * Conversely, the "signal" command now consistently delivers the
1134 requested signal to the current thread. GDB now asks for
1135 confirmation if the program had stopped for a signal and the user
1136 switched threads meanwhile.
1138 * "breakpoint always-inserted" modes "off" and "auto" merged.
1140 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1141 won't remove breakpoints from the target until all threads stop,
1142 even in non-stop mode. The "auto" mode has been removed, and "off"
1143 is now the default mode.
1147 set debug symbol-lookup
1148 show debug symbol-lookup
1149 Control display of debugging info regarding symbol lookup.
1153 ** The -list-thread-groups command outputs an exit-code field for
1154 inferiors that have exited.
1158 MIPS SDE mips*-sde*-elf*
1162 Support for these obsolete configurations has been removed.
1164 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1165 SGI Irix-5.x mips-*-irix5*
1166 SGI Irix-6.x mips-*-irix6*
1167 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1168 VAX running Ultrix vax-*-ultrix*
1170 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1171 and "assf"), have been removed. Use the "sharedlibrary" command, or
1172 its alias "share", instead.
1174 *** Changes in GDB 7.8
1176 * New command line options
1179 This is an alias for the --data-directory option.
1181 * GDB supports printing and modifying of variable length automatic arrays
1182 as specified in ISO C99.
1184 * The ARM simulator now supports instruction level tracing
1185 with or without disassembly.
1189 GDB now has support for scripting using Guile. Whether this is
1190 available is determined at configure time.
1191 Guile version 2.0 or greater is required.
1192 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1194 * New commands (for set/show, see "New options" below)
1198 Invoke CODE by passing it to the Guile interpreter.
1202 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1204 info auto-load guile-scripts [regexp]
1205 Print the list of automatically loaded Guile scripts.
1207 * The source command is now capable of sourcing Guile scripts.
1208 This feature is dependent on the debugger being built with Guile support.
1212 set print symbol-loading (off|brief|full)
1213 show print symbol-loading
1214 Control whether to print informational messages when loading symbol
1215 information for a file. The default is "full", but when debugging
1216 programs with large numbers of shared libraries the amount of output
1217 becomes less useful.
1219 set guile print-stack (none|message|full)
1220 show guile print-stack
1221 Show a stack trace when an error is encountered in a Guile script.
1223 set auto-load guile-scripts (on|off)
1224 show auto-load guile-scripts
1225 Control auto-loading of Guile script files.
1227 maint ada set ignore-descriptive-types (on|off)
1228 maint ada show ignore-descriptive-types
1229 Control whether the debugger should ignore descriptive types in Ada
1230 programs. The default is not to ignore the descriptive types. See
1231 the user manual for more details on descriptive types and the intended
1232 usage of this option.
1234 set auto-connect-native-target
1236 Control whether GDB is allowed to automatically connect to the
1237 native target for the run, attach, etc. commands when not connected
1238 to any target yet. See also "target native" below.
1240 set record btrace replay-memory-access (read-only|read-write)
1241 show record btrace replay-memory-access
1242 Control what memory accesses are allowed during replay.
1244 maint set target-async (on|off)
1245 maint show target-async
1246 This controls whether GDB targets operate in synchronous or
1247 asynchronous mode. Normally the default is asynchronous, if it is
1248 available; but this can be changed to more easily debug problems
1249 occurring only in synchronous mode.
1251 set mi-async (on|off)
1253 Control whether MI asynchronous mode is preferred. This supersedes
1254 "set target-async" of previous GDB versions.
1256 * "set target-async" is deprecated as a CLI option and is now an alias
1257 for "set mi-async" (only puts MI into async mode).
1259 * Background execution commands (e.g., "c&", "s&", etc.) are now
1260 possible ``out of the box'' if the target supports them. Previously
1261 the user would need to explicitly enable the possibility with the
1262 "set target-async on" command.
1264 * New features in the GDB remote stub, GDBserver
1266 ** New option --debug-format=option1[,option2,...] allows one to add
1267 additional text to each output. At present only timestamps
1268 are supported: --debug-format=timestamps.
1269 Timestamps can also be turned on with the
1270 "monitor set debug-format timestamps" command from GDB.
1272 * The 'record instruction-history' command now starts counting instructions
1273 at one. This also affects the instruction ranges reported by the
1274 'record function-call-history' command when given the /i modifier.
1276 * The command 'record function-call-history' supports a new modifier '/c' to
1277 indent the function names based on their call stack depth.
1278 The fields for the '/i' and '/l' modifier have been reordered.
1279 The source line range is now prefixed with 'at'.
1280 The instruction range is now prefixed with 'inst'.
1281 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1282 "record instruction-history" and "list" commands.
1284 * The ranges given as arguments to the 'record function-call-history' and
1285 'record instruction-history' commands are now inclusive.
1287 * The btrace record target now supports the 'record goto' command.
1288 For locations inside the execution trace, the back trace is computed
1289 based on the information stored in the execution trace.
1291 * The btrace record target supports limited reverse execution and replay.
1292 The target does not record data and therefore does not allow reading
1293 memory or registers.
1295 * The "catch syscall" command now works on s390*-linux* targets.
1297 * The "compare-sections" command is no longer specific to target
1298 remote. It now works with all targets.
1300 * All native targets are now consistently called "native".
1301 Consequently, the "target child", "target GNU", "target djgpp",
1302 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1303 commands have been replaced with "target native". The QNX/NTO port
1304 leaves the "procfs" target in place and adds a "native" target for
1305 consistency with other ports. The impact on users should be minimal
1306 as these commands previously either throwed an error, or were
1307 no-ops. The target's name is visible in the output of the following
1308 commands: "help target", "info target", "info files", "maint print
1311 * The "target native" command now connects to the native target. This
1312 can be used to launch native programs even when "set
1313 auto-connect-native-target" is set to off.
1315 * GDB now supports access to Intel MPX registers on GNU/Linux.
1317 * Support for Intel AVX-512 registers on GNU/Linux.
1318 Support displaying and modifying Intel AVX-512 registers
1319 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1321 * New remote packets
1323 qXfer:btrace:read's annex
1324 The qXfer:btrace:read packet supports a new annex 'delta' to read
1325 branch trace incrementally.
1329 ** Valid Python operations on gdb.Value objects representing
1330 structs/classes invoke the corresponding overloaded operators if
1332 ** New `Xmethods' feature in the Python API. Xmethods are
1333 additional methods or replacements for existing methods of a C++
1334 class. This feature is useful for those cases where a method
1335 defined in C++ source code could be inlined or optimized out by
1336 the compiler, making it unavailable to GDB.
1339 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1341 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1342 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1343 its alias "share", instead.
1345 * The commands "set remotebaud" and "show remotebaud" are no longer
1346 supported. Use "set serial baud" and "show serial baud" (respectively)
1351 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1352 target-async". The latter is left as a deprecated alias of the
1353 former for backward compatibility. If the target supports it,
1354 CLI background execution commands are now always possible by
1355 default, independently of whether the frontend stated a
1356 preference for asynchronous execution with "-gdb-set mi-async".
1357 Previously "-gdb-set target-async off" affected both MI execution
1358 commands and CLI execution commands.
1360 *** Changes in GDB 7.7
1362 * Improved support for process record-replay and reverse debugging on
1363 arm*-linux* targets. Support for thumb32 and syscall instruction
1364 recording has been added.
1366 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1368 * GDB now supports Fission DWP file format version 2.
1369 http://gcc.gnu.org/wiki/DebugFission
1371 * New convenience function "$_isvoid", to check whether an expression
1372 is void. A void expression is an expression where the type of the
1373 result is "void". For example, some convenience variables may be
1374 "void" when evaluated (e.g., "$_exitcode" before the execution of
1375 the program being debugged; or an undefined convenience variable).
1376 Another example, when calling a function whose return type is
1379 * The "maintenance print objfiles" command now takes an optional regexp.
1381 * The "catch syscall" command now works on arm*-linux* targets.
1383 * GDB now consistently shows "<not saved>" when printing values of
1384 registers the debug info indicates have not been saved in the frame
1385 and there's nowhere to retrieve them from
1386 (callee-saved/call-clobbered registers):
1391 (gdb) info registers rax
1394 Before, the former would print "<optimized out>", and the latter
1395 "*value not available*".
1397 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1402 ** Frame filters and frame decorators have been added.
1403 ** Temporary breakpoints are now supported.
1404 ** Line tables representation has been added.
1405 ** New attribute 'parent_type' for gdb.Field objects.
1406 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1407 ** New attribute 'name' for gdb.Type objects.
1411 Nios II ELF nios2*-*-elf
1412 Nios II GNU/Linux nios2*-*-linux
1413 Texas Instruments MSP430 msp430*-*-elf
1415 * Removed native configurations
1417 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1418 been removed. ELF variants of these configurations are kept supported.
1420 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1421 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1422 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1423 i[34567]86-*-openbsd3.[0-3]
1424 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1425 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1426 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1430 Like "catch throw", but catches a re-thrown exception.
1431 maint check-psymtabs
1432 Renamed from old "maint check-symtabs".
1434 Perform consistency checks on symtabs.
1435 maint expand-symtabs
1436 Expand symtabs matching an optional regexp.
1439 Display the details of GDB configure-time options.
1441 maint set|show per-command
1442 maint set|show per-command space
1443 maint set|show per-command time
1444 maint set|show per-command symtab
1445 Enable display of per-command gdb resource usage.
1447 remove-symbol-file FILENAME
1448 remove-symbol-file -a ADDRESS
1449 Remove a symbol file added via add-symbol-file. The file to remove
1450 can be identified by its filename or by an address that lies within
1451 the boundaries of this symbol file in memory.
1454 info exceptions REGEXP
1455 Display the list of Ada exceptions defined in the program being
1456 debugged. If provided, only the exceptions whose names match REGEXP
1461 set debug symfile off|on
1463 Control display of debugging info regarding reading symbol files and
1464 symbol tables within those files
1466 set print raw frame-arguments
1467 show print raw frame-arguments
1468 Set/show whether to print frame arguments in raw mode,
1469 disregarding any defined pretty-printers.
1471 set remote trace-status-packet
1472 show remote trace-status-packet
1473 Set/show the use of remote protocol qTStatus packet.
1477 Control display of debugging messages related to Nios II targets.
1481 Control whether target-assisted range stepping is enabled.
1483 set startup-with-shell
1484 show startup-with-shell
1485 Specifies whether Unix child processes are started via a shell or
1490 Use the target memory cache for accesses to the code segment. This
1491 improves performance of remote debugging (particularly disassembly).
1493 * You can now use a literal value 'unlimited' for options that
1494 interpret 0 or -1 as meaning "unlimited". E.g., "set
1495 trace-buffer-size unlimited" is now an alias for "set
1496 trace-buffer-size -1" and "set height unlimited" is now an alias for
1499 * The "set debug symtab-create" debugging option of GDB has been changed to
1500 accept a verbosity level. 0 means "off", 1 provides basic debugging
1501 output, and values of 2 or greater provides more verbose output.
1503 * New command-line options
1505 Display the details of GDB configure-time options.
1507 * The command 'tsave' can now support new option '-ctf' to save trace
1508 buffer in Common Trace Format.
1510 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1513 * GDB now implements the the C++ 'typeid' operator.
1515 * The new convenience variable $_exception holds the exception being
1516 thrown or caught at an exception-related catchpoint.
1518 * The exception-related catchpoints, like "catch throw", now accept a
1519 regular expression which can be used to filter exceptions by type.
1521 * The new convenience variable $_exitsignal is automatically set to
1522 the terminating signal number when the program being debugged dies
1523 due to an uncaught signal.
1527 ** All MI commands now accept an optional "--language" option.
1528 Support for this feature can be verified by using the "-list-features"
1529 command, which should contain "language-option".
1531 ** The new command -info-gdb-mi-command allows the user to determine
1532 whether a GDB/MI command is supported or not.
1534 ** The "^error" result record returned when trying to execute an undefined
1535 GDB/MI command now provides a variable named "code" whose content is the
1536 "undefined-command" error code. Support for this feature can be verified
1537 by using the "-list-features" command, which should contain
1538 "undefined-command-error-code".
1540 ** The -trace-save MI command can optionally save trace buffer in Common
1543 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1545 ** The command -data-list-register-values now accepts an optional
1546 "--skip-unavailable" option. When used, only the available registers
1549 ** The new command -trace-frame-collected dumps collected variables,
1550 computed expressions, tvars, memory and registers in a traceframe.
1552 ** The commands -stack-list-locals, -stack-list-arguments and
1553 -stack-list-variables now accept an option "--skip-unavailable".
1554 When used, only the available locals or arguments are displayed.
1556 ** The -exec-run command now accepts an optional "--start" option.
1557 When used, the command follows the same semantics as the "start"
1558 command, stopping the program's execution at the start of its
1559 main subprogram. Support for this feature can be verified using
1560 the "-list-features" command, which should contain
1561 "exec-run-start-option".
1563 ** The new commands -catch-assert and -catch-exceptions insert
1564 catchpoints stopping the program when Ada exceptions are raised.
1566 ** The new command -info-ada-exceptions provides the equivalent of
1567 the new "info exceptions" command.
1569 * New system-wide configuration scripts
1570 A GDB installation now provides scripts suitable for use as system-wide
1571 configuration scripts for the following systems:
1575 * GDB now supports target-assigned range stepping with remote targets.
1576 This improves the performance of stepping source lines by reducing
1577 the number of control packets from/to GDB. See "New remote packets"
1580 * GDB now understands the element 'tvar' in the XML traceframe info.
1581 It has the id of the collected trace state variables.
1583 * On S/390 targets that provide the transactional-execution feature,
1584 the program interruption transaction diagnostic block (TDB) is now
1585 represented as a number of additional "registers" in GDB.
1587 * New remote packets
1591 The vCont packet supports a new 'r' action, that tells the remote
1592 stub to step through an address range itself, without GDB
1593 involvemement at each single-step.
1595 qXfer:libraries-svr4:read's annex
1596 The previously unused annex of the qXfer:libraries-svr4:read packet
1597 is now used to support passing an argument list. The remote stub
1598 reports support for this argument list to GDB's qSupported query.
1599 The defined arguments are "start" and "prev", used to reduce work
1600 necessary for library list updating, resulting in significant
1603 * New features in the GDB remote stub, GDBserver
1605 ** GDBserver now supports target-assisted range stepping. Currently
1606 enabled on x86/x86_64 GNU/Linux targets.
1608 ** GDBserver now adds element 'tvar' in the XML in the reply to
1609 'qXfer:traceframe-info:read'. It has the id of the collected
1610 trace state variables.
1612 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1615 * New 'z' formatter for printing and examining memory, this displays the
1616 value as hexadecimal zero padded on the left to the size of the type.
1618 * GDB can now use Windows x64 unwinding data.
1620 * The "set remotebaud" command has been replaced by "set serial baud".
1621 Similarly, "show remotebaud" has been replaced by "show serial baud".
1622 The "set remotebaud" and "show remotebaud" commands are still available
1623 to provide backward compatibility with older versions of GDB.
1625 *** Changes in GDB 7.6
1627 * Target record has been renamed to record-full.
1628 Record/replay is now enabled with the "record full" command.
1629 This also affects settings that are associated with full record/replay
1630 that have been moved from "set/show record" to "set/show record full":
1632 set|show record full insn-number-max
1633 set|show record full stop-at-limit
1634 set|show record full memory-query
1636 * A new record target "record-btrace" has been added. The new target
1637 uses hardware support to record the control-flow of a process. It
1638 does not support replaying the execution, but it implements the
1639 below new commands for investigating the recorded execution log.
1640 This new recording method can be enabled using:
1644 The "record-btrace" target is only available on Intel Atom processors
1645 and requires a Linux kernel 2.6.32 or later.
1647 * Two new commands have been added for record/replay to give information
1648 about the recorded execution without having to replay the execution.
1649 The commands are only supported by "record btrace".
1651 record instruction-history prints the execution history at
1652 instruction granularity
1654 record function-call-history prints the execution history at
1655 function granularity
1657 * New native configurations
1659 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1660 FreeBSD/powerpc powerpc*-*-freebsd
1661 x86_64/Cygwin x86_64-*-cygwin*
1662 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1666 ARM AArch64 aarch64*-*-elf
1667 ARM AArch64 GNU/Linux aarch64*-*-linux
1668 Lynx 178 PowerPC powerpc-*-lynx*178
1669 x86_64/Cygwin x86_64-*-cygwin*
1670 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1672 * If the configured location of system.gdbinit file (as given by the
1673 --with-system-gdbinit option at configure time) is in the
1674 data-directory (as specified by --with-gdb-datadir at configure
1675 time) or in one of its subdirectories, then GDB will look for the
1676 system-wide init file in the directory specified by the
1677 --data-directory command-line option.
1679 * New command line options:
1681 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1682 other initialization files, unlike -nx which disables all of them.
1684 * Removed command line options
1686 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1689 * The 'ptype' and 'whatis' commands now accept an argument to control
1692 * 'info proc' now works on some core files.
1696 ** Vectors can be created with gdb.Type.vector.
1698 ** Python's atexit.register now works in GDB.
1700 ** Types can be pretty-printed via a Python API.
1702 ** Python 3 is now supported (in addition to Python 2.4 or later)
1704 ** New class gdb.Architecture exposes GDB's internal representation
1705 of architecture in the Python API.
1707 ** New method Frame.architecture returns the gdb.Architecture object
1708 corresponding to the frame's architecture.
1710 * New Python-based convenience functions:
1712 ** $_memeq(buf1, buf2, length)
1713 ** $_streq(str1, str2)
1715 ** $_regex(str, regex)
1717 * The 'cd' command now defaults to using '~' (the home directory) if not
1720 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1721 default for GCC since November 2000.
1723 * The command 'forward-search' can now be abbreviated as 'fo'.
1725 * The command 'info tracepoints' can now display 'installed on target'
1726 or 'not installed on target' for each non-pending location of tracepoint.
1728 * New configure options
1730 --enable-libmcheck/--disable-libmcheck
1731 By default, development versions are built with -lmcheck on hosts
1732 that support it, in order to help track memory corruption issues.
1733 Release versions, on the other hand, are built without -lmcheck
1734 by default. The --enable-libmcheck/--disable-libmcheck configure
1735 options allow the user to override that default.
1736 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1737 This configure option allows the user to build GDB with
1738 libbabeltrace using which GDB can read Common Trace Format data.
1740 * New commands (for set/show, see "New options" below)
1743 Catch signals. This is similar to "handle", but allows commands and
1744 conditions to be attached.
1747 List the BFDs known to GDB.
1749 python-interactive [command]
1751 Start a Python interactive prompt, or evaluate the optional command
1752 and print the result of expressions.
1755 "py" is a new alias for "python".
1757 enable type-printer [name]...
1758 disable type-printer [name]...
1759 Enable or disable type printers.
1763 ** For the Renesas Super-H architecture, the "regs" command has been removed
1764 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1769 set print type methods (on|off)
1770 show print type methods
1771 Control whether method declarations are displayed by "ptype".
1772 The default is to show them.
1774 set print type typedefs (on|off)
1775 show print type typedefs
1776 Control whether typedef definitions are displayed by "ptype".
1777 The default is to show them.
1779 set filename-display basename|relative|absolute
1780 show filename-display
1781 Control the way in which filenames is displayed.
1782 The default is "relative", which preserves previous behavior.
1784 set trace-buffer-size
1785 show trace-buffer-size
1786 Request target to change the size of trace buffer.
1788 set remote trace-buffer-size-packet auto|on|off
1789 show remote trace-buffer-size-packet
1790 Control the use of the remote protocol `QTBuffer:size' packet.
1794 Control display of debugging messages related to ARM AArch64.
1797 set debug coff-pe-read
1798 show debug coff-pe-read
1799 Control display of debugging messages related to reading of COFF/PE
1804 Control display of debugging messages related to Mach-O symbols
1807 set debug notification
1808 show debug notification
1809 Control display of debugging info for async remote notification.
1813 ** Command parameter changes are now notified using new async record
1814 "=cmd-param-changed".
1815 ** Trace frame changes caused by command "tfind" are now notified using
1816 new async record "=traceframe-changed".
1817 ** The creation, deletion and modification of trace state variables
1818 are now notified using new async records "=tsv-created",
1819 "=tsv-deleted" and "=tsv-modified".
1820 ** The start and stop of process record are now notified using new
1821 async record "=record-started" and "=record-stopped".
1822 ** Memory changes are now notified using new async record
1824 ** The data-disassemble command response will include a "fullname" field
1825 containing the absolute file name when source has been requested.
1826 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1827 command, to allow pattern filling of memory areas.
1828 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1829 library load/unload events.
1830 ** The response to breakpoint commands and breakpoint async records
1831 includes an "installed" field containing a boolean state about each
1832 non-pending tracepoint location is whether installed on target or not.
1833 ** Output of the "-trace-status" command includes a "trace-file" field
1834 containing the name of the trace file being examined. This field is
1835 optional, and only present when examining a trace file.
1836 ** The "fullname" field is now always present along with the "file" field,
1837 even if the file cannot be found by GDB.
1839 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1840 You must have the LZMA library available when configuring GDB for this
1841 feature to be enabled. For more information, see:
1842 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1844 * New remote packets
1847 Set the size of trace buffer. The remote stub reports support for this
1848 packet to gdb's qSupported query.
1851 Enable Branch Trace Store (BTS)-based branch tracing for the current
1852 thread. The remote stub reports support for this packet to gdb's
1856 Disable branch tracing for the current thread. The remote stub reports
1857 support for this packet to gdb's qSupported query.
1860 Read the traced branches for the current thread. The remote stub
1861 reports support for this packet to gdb's qSupported query.
1863 *** Changes in GDB 7.5
1865 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1866 for more x32 ABI info.
1868 * GDB now supports access to MIPS DSP registers on Linux targets.
1870 * GDB now supports debugging microMIPS binaries.
1872 * The "info os" command on GNU/Linux can now display information on
1873 several new classes of objects managed by the operating system:
1874 "info os procgroups" lists process groups
1875 "info os files" lists file descriptors
1876 "info os sockets" lists internet-domain sockets
1877 "info os shm" lists shared-memory regions
1878 "info os semaphores" lists semaphores
1879 "info os msg" lists message queues
1880 "info os modules" lists loaded kernel modules
1882 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1883 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1884 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1885 options and inspect the probe arguments using the new $_probe_arg family
1886 of convenience variables. You can obtain more information about SystemTap
1887 in <http://sourceware.org/systemtap/>.
1889 * GDB now supports reversible debugging on ARM, it allows you to
1890 debug basic ARM and THUMB instructions, and provides
1891 record/replay support.
1893 * The option "symbol-reloading" has been deleted as it is no longer used.
1897 ** GDB commands implemented in Python can now be put in command class
1900 ** The "maint set python print-stack on|off" is now deleted.
1902 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1903 apply "flag enum"-style pretty-printing to any enum.
1905 ** gdb.lookup_symbol can now work when there is no current frame.
1907 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1908 the source at which the symbol was defined.
1910 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1911 method 'value'. The former indicates whether the symbol needs a
1912 frame in order to compute its value, and the latter computes the
1915 ** A new method 'referenced_value' on gdb.Value objects which can
1916 dereference pointer as well as C++ reference values.
1918 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1919 which return the global and static blocks (as gdb.Block objects),
1920 of the underlying symbol table, respectively.
1922 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1923 object associated with a PC value.
1925 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1926 of the address range occupied by code for the current source line.
1928 * Go language support.
1929 GDB now supports debugging programs written in the Go programming
1932 * GDBserver now supports stdio connections.
1933 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1935 * The binary "gdbtui" can no longer be built or installed.
1936 Use "gdb -tui" instead.
1938 * GDB will now print "flag" enums specially. A flag enum is one where
1939 all the enumerator values have no bits in common when pairwise
1940 "and"ed. When printing a value whose type is a flag enum, GDB will
1941 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1942 (gdb) print (enum E) 3
1945 * The filename part of a linespec will now match trailing components
1946 of a source file name. For example, "break gcc/expr.c:1000" will
1947 now set a breakpoint in build/gcc/expr.c, but not
1948 build/libcpp/expr.c.
1950 * The "info proc" and "generate-core-file" commands will now also
1951 work on remote targets connected to GDBserver on Linux.
1953 * The command "info catch" has been removed. It has been disabled
1954 since December 2007.
1956 * The "catch exception" and "catch assert" commands now accept
1957 a condition at the end of the command, much like the "break"
1958 command does. For instance:
1960 (gdb) catch exception Constraint_Error if Barrier = True
1962 Previously, it was possible to add a condition to such catchpoints,
1963 but it had to be done as a second step, after the catchpoint had been
1964 created, using the "condition" command.
1966 * The "info static-tracepoint-marker" command will now also work on
1967 native Linux targets with in-process agent.
1969 * GDB can now set breakpoints on inlined functions.
1971 * The .gdb_index section has been updated to include symbols for
1972 inlined functions. GDB will ignore older .gdb_index sections by
1973 default, which could cause symbol files to be loaded more slowly
1974 until their .gdb_index sections can be recreated. The new command
1975 "set use-deprecated-index-sections on" will cause GDB to use any older
1976 .gdb_index sections it finds. This will restore performance, but the
1977 ability to set breakpoints on inlined functions will be lost in symbol
1978 files with older .gdb_index sections.
1980 The .gdb_index section has also been updated to record more information
1981 about each symbol. This speeds up the "info variables", "info functions"
1982 and "info types" commands when used with programs having the .gdb_index
1983 section, as well as speeding up debugging with shared libraries using
1984 the .gdb_index section.
1986 * Ada support for GDB/MI Variable Objects has been added.
1988 * GDB can now support 'breakpoint always-inserted mode' in 'record'
1993 ** New command -info-os is the MI equivalent of "info os".
1995 ** Output logs ("set logging" and related) now include MI output.
1999 ** "set use-deprecated-index-sections on|off"
2000 "show use-deprecated-index-sections on|off"
2001 Controls the use of deprecated .gdb_index sections.
2003 ** "catch load" and "catch unload" can be used to stop when a shared
2004 library is loaded or unloaded, respectively.
2006 ** "enable count" can be used to auto-disable a breakpoint after
2009 ** "info vtbl" can be used to show the virtual method tables for
2010 C++ and Java objects.
2012 ** "explore" and its sub commands "explore value" and "explore type"
2013 can be used to recursively explore values and types of
2014 expressions. These commands are available only if GDB is
2015 configured with '--with-python'.
2017 ** "info auto-load" shows status of all kinds of auto-loaded files,
2018 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2019 sequences of commands files, "info auto-load python-scripts"
2020 shows status of auto-loading Python script files,
2021 "info auto-load local-gdbinit" shows status of loading init file
2022 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2023 status of inferior specific thread debugging shared library loading.
2025 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2026 and "show auto-load-scripts" commands have been deprecated, use their
2027 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2028 and "show auto-load python-scripts" counterparts instead.
2030 ** "dprintf location,format,args..." creates a dynamic printf, which
2031 is basically a breakpoint that does a printf and immediately
2032 resumes your program's execution, so it is like a printf that you
2033 can insert dynamically at runtime instead of at compiletime.
2035 ** "set print symbol"
2037 Controls whether GDB attempts to display the symbol, if any,
2038 corresponding to addresses it prints. This defaults to "on", but
2039 you can set it to "off" to restore GDB's previous behavior.
2041 * Deprecated commands
2043 ** For the Renesas Super-H architecture, the "regs" command has been
2044 deprecated, and "info all-registers" should be used instead.
2048 Renesas RL78 rl78-*-elf
2049 HP OpenVMS ia64 ia64-hp-openvms*
2051 * GDBserver supports evaluation of breakpoint conditions. When
2052 support is advertised by GDBserver, GDB may be told to send the
2053 breakpoint conditions in bytecode form to GDBserver. GDBserver
2054 will only report the breakpoint trigger to GDB when its condition
2059 set mips compression
2060 show mips compression
2061 Select the compressed ISA encoding used in functions that have no symbol
2062 information available. The encoding can be set to either of:
2065 and is updated automatically from ELF file flags if available.
2067 set breakpoint condition-evaluation
2068 show breakpoint condition-evaluation
2069 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2070 GDBserver ("target"). Default option "auto" chooses the most efficient
2072 This option can improve debugger efficiency depending on the speed of the
2076 Disable auto-loading globally.
2079 Show auto-loading setting of all kinds of auto-loaded files.
2081 set auto-load gdb-scripts on|off
2082 show auto-load gdb-scripts
2083 Control auto-loading of GDB canned sequences of commands files.
2085 set auto-load python-scripts on|off
2086 show auto-load python-scripts
2087 Control auto-loading of Python script files.
2089 set auto-load local-gdbinit on|off
2090 show auto-load local-gdbinit
2091 Control loading of init file (.gdbinit) from current directory.
2093 set auto-load libthread-db on|off
2094 show auto-load libthread-db
2095 Control auto-loading of inferior specific thread debugging shared library.
2097 set auto-load scripts-directory <dir1>[:<dir2>...]
2098 show auto-load scripts-directory
2099 Set a list of directories from which to load auto-loaded scripts.
2100 Automatically loaded Python scripts and GDB scripts are located in one
2101 of the directories listed by this option.
2102 The delimiter (':' above) may differ according to the host platform.
2104 set auto-load safe-path <dir1>[:<dir2>...]
2105 show auto-load safe-path
2106 Set a list of directories from which it is safe to auto-load files.
2107 The delimiter (':' above) may differ according to the host platform.
2109 set debug auto-load on|off
2110 show debug auto-load
2111 Control display of debugging info for auto-loading the files above.
2113 set dprintf-style gdb|call|agent
2115 Control the way in which a dynamic printf is performed; "gdb"
2116 requests a GDB printf command, while "call" causes dprintf to call a
2117 function in the inferior. "agent" requests that the target agent
2118 (such as GDBserver) do the printing.
2120 set dprintf-function <expr>
2121 show dprintf-function
2122 set dprintf-channel <expr>
2123 show dprintf-channel
2124 Set the function and optional first argument to the call when using
2125 the "call" style of dynamic printf.
2127 set disconnected-dprintf on|off
2128 show disconnected-dprintf
2129 Control whether agent-style dynamic printfs continue to be in effect
2130 after GDB disconnects.
2132 * New configure options
2134 --with-auto-load-dir
2135 Configure default value for the 'set auto-load scripts-directory'
2136 setting above. It defaults to '$debugdir:$datadir/auto-load',
2137 $debugdir representing global debugging info directories (available
2138 via 'show debug-file-directory') and $datadir representing GDB's data
2139 directory (available via 'show data-directory').
2141 --with-auto-load-safe-path
2142 Configure default value for the 'set auto-load safe-path' setting
2143 above. It defaults to the --with-auto-load-dir setting.
2145 --without-auto-load-safe-path
2146 Set 'set auto-load safe-path' to '/', effectively disabling this
2149 * New remote packets
2151 z0/z1 conditional breakpoints extension
2153 The z0/z1 breakpoint insertion packets have been extended to carry
2154 a list of conditional expressions over to the remote stub depending on the
2155 condition evaluation mode. The use of this extension can be controlled
2156 via the "set remote conditional-breakpoints-packet" command.
2160 Specify the signals which the remote stub may pass to the debugged
2161 program without GDB involvement.
2163 * New command line options
2165 --init-command=FILE, -ix Like --command, -x but execute it
2166 before loading inferior.
2167 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2168 execute it before loading inferior.
2170 *** Changes in GDB 7.4
2172 * GDB now handles ambiguous linespecs more consistently; the existing
2173 FILE:LINE support has been expanded to other types of linespecs. A
2174 breakpoint will now be set on all matching locations in all
2175 inferiors, and locations will be added or removed according to
2178 * GDB now allows you to skip uninteresting functions and files when
2179 stepping with the "skip function" and "skip file" commands.
2181 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2182 and "show remote hardware-watchpoint-length-limit". These allows to
2183 set or show the maximum length limit (in bytes) of a remote
2184 target hardware watchpoint.
2186 This allows e.g. to use "unlimited" hardware watchpoints with the
2187 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2188 watchpoints are slower than real hardware watchpoints but are
2189 significantly faster than gdb software watchpoints.
2193 ** The register_pretty_printer function in module gdb.printing now takes
2194 an optional `replace' argument. If True, the new printer replaces any
2197 ** The "maint set python print-stack on|off" command has been
2198 deprecated and will be deleted in GDB 7.5.
2199 A new command: "set python print-stack none|full|message" has
2200 replaced it. Additionally, the default for "print-stack" is
2201 now "message", which just prints the error message without
2204 ** A prompt substitution hook (prompt_hook) is now available to the
2207 ** A new Python module, gdb.prompt has been added to the GDB Python
2208 modules library. This module provides functionality for
2209 escape sequences in prompts (used by set/show
2210 extended-prompt). These escape sequences are replaced by their
2211 corresponding value.
2213 ** Python commands and convenience-functions located in
2214 'data-directory'/python/gdb/command and
2215 'data-directory'/python/gdb/function are now automatically loaded
2218 ** Blocks now provide four new attributes. global_block and
2219 static_block will return the global and static blocks
2220 respectively. is_static and is_global are boolean attributes
2221 that indicate if the block is one of those two types.
2223 ** Symbols now provide the "type" attribute, the type of the symbol.
2225 ** The "gdb.breakpoint" function has been deprecated in favor of
2228 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2229 of a function. This class is based on the "finish" command
2230 available in the CLI.
2232 ** Type objects for struct and union types now allow access to
2233 the fields using standard Python dictionary (mapping) methods.
2234 For example, "some_type['myfield']" now works, as does
2235 "some_type.items()".
2237 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2240 ** A new function, "deep_items" has been added to the gdb.types
2241 module in the GDB Python modules library. This function returns
2242 an iterator over the fields of a struct or union type. Unlike
2243 the standard Python "iteritems" method, it will recursively traverse
2244 any anonymous fields.
2248 ** "*stopped" events can report several new "reason"s, such as
2251 ** Breakpoint changes are now notified using new async records, like
2252 "=breakpoint-modified".
2254 ** New command -ada-task-info.
2256 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2257 $sdir specifies the default system locations of shared libraries.
2258 $pdir specifies the directory where the libpthread used by the application
2261 GDB no longer looks in $sdir and $pdir after it has searched the directories
2262 mentioned in libthread-db-search-path. If you want to search those
2263 directories, they must be specified in libthread-db-search-path.
2264 The default value of libthread-db-search-path on GNU/Linux and Solaris
2265 systems is now "$sdir:$pdir".
2267 $pdir is not supported by gdbserver, it is currently ignored.
2268 $sdir is supported by gdbserver.
2270 * New configure option --with-iconv-bin.
2271 When using the internationalization support like the one in the GNU C
2272 library, GDB will invoke the "iconv" program to get a list of supported
2273 character sets. If this program lives in a non-standard location, one can
2274 use this option to specify where to find it.
2276 * When natively debugging programs on PowerPC BookE processors running
2277 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2278 watchpoints, which specify a mask in addition to an address to watch.
2279 The mask specifies that some bits of an address (the bits which are
2280 reset in the mask) should be ignored when matching the address accessed
2281 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2282 section in the user manual for more details.
2284 * The new option --once causes GDBserver to stop listening for connections once
2285 the first connection is made. The listening port used by GDBserver will
2286 become available after that.
2288 * New commands "info macros" and "alias" have been added.
2290 * New function parameters suffix @entry specifies value of function parameter
2291 at the time the function got called. Entry values are available only since
2297 "!" is now an alias of the "shell" command.
2298 Note that no space is needed between "!" and SHELL COMMAND.
2302 watch EXPRESSION mask MASK_VALUE
2303 The watch command now supports the mask argument which allows creation
2304 of masked watchpoints, if the current architecture supports this feature.
2306 info auto-load-scripts [REGEXP]
2307 This command was formerly named "maintenance print section-scripts".
2308 It is now generally useful and is no longer a maintenance-only command.
2310 info macro [-all] [--] MACRO
2311 The info macro command has new options `-all' and `--'. The first for
2312 printing all definitions of a macro. The second for explicitly specifying
2313 the end of arguments and the beginning of the macro name in case the macro
2314 name starts with a hyphen.
2316 collect[/s] EXPRESSIONS
2317 The tracepoint collect command now takes an optional modifier "/s"
2318 that directs it to dereference pointer-to-character types and
2319 collect the bytes of memory up to a zero byte. The behavior is
2320 similar to what you see when you use the regular print command on a
2321 string. An optional integer following the "/s" sets a bound on the
2322 number of bytes that will be collected.
2325 The trace start command now interprets any supplied arguments as a
2326 note to be recorded with the trace run, with an effect similar to
2327 setting the variable trace-notes.
2330 The trace stop command now interprets any arguments as a note to be
2331 mentioned along with the tstatus report that the trace was stopped
2332 with a command. The effect is similar to setting the variable
2335 * Tracepoints can now be enabled and disabled at any time after a trace
2336 experiment has been started using the standard "enable" and "disable"
2337 commands. It is now possible to start a trace experiment with no enabled
2338 tracepoints; GDB will display a warning, but will allow the experiment to
2339 begin, assuming that tracepoints will be enabled as needed while the trace
2342 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2343 locations with 4-byte instructions, when they were previously
2344 limited to locations with instructions of 5 bytes or longer.
2348 set debug dwarf2-read
2349 show debug dwarf2-read
2350 Turns on or off display of debugging messages related to reading
2351 DWARF debug info. The default is off.
2353 set debug symtab-create
2354 show debug symtab-create
2355 Turns on or off display of debugging messages related to symbol table
2356 creation. The default is off.
2359 show extended-prompt
2360 Set the GDB prompt, and allow escape sequences to be inserted to
2361 display miscellaneous information (see 'help set extended-prompt'
2362 for the list of sequences). This prompt (and any information
2363 accessed through the escape sequences) is updated every time the
2364 prompt is displayed.
2366 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2367 show print entry-values
2368 Set printing of frame argument values at function entry. In some cases
2369 GDB can determine the value of function argument which was passed by the
2370 function caller, even if the value was modified inside the called function.
2372 set debug entry-values
2373 show debug entry-values
2374 Control display of debugging info for determining frame argument values at
2375 function entry and virtual tail call frames.
2377 set basenames-may-differ
2378 show basenames-may-differ
2379 Set whether a source file may have multiple base names.
2380 (A "base name" is the name of a file with the directory part removed.
2381 Example: The base name of "/home/user/hello.c" is "hello.c".)
2382 If set, GDB will canonicalize file names (e.g., expand symlinks)
2383 before comparing them. Canonicalization is an expensive operation,
2384 but it allows the same file be known by more than one base name.
2385 If not set (the default), all source files are assumed to have just
2386 one base name, and gdb will do file name comparisons more efficiently.
2392 Set a user name and notes for the current and any future trace runs.
2393 This is useful for long-running and/or disconnected traces, to
2394 inform others (or yourself) as to who is running the trace, supply
2395 contact information, or otherwise explain what is going on.
2397 set trace-stop-notes
2398 show trace-stop-notes
2399 Set a note attached to the trace run, that is displayed when the
2400 trace has been stopped by a tstop command. This is useful for
2401 instance as an explanation, if you are stopping a trace run that was
2402 started by someone else.
2404 * New remote packets
2408 Dynamically enable a tracepoint in a started trace experiment.
2412 Dynamically disable a tracepoint in a started trace experiment.
2416 Set the user and notes of the trace run.
2420 Query the current status of a tracepoint.
2424 Query the minimum length of instruction at which a fast tracepoint may
2427 * Dcache size (number of lines) and line-size are now runtime-configurable
2428 via "set dcache line" and "set dcache line-size" commands.
2432 Texas Instruments TMS320C6x tic6x-*-*
2436 Renesas RL78 rl78-*-elf
2438 *** Changes in GDB 7.3.1
2440 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2442 *** Changes in GDB 7.3
2444 * GDB has a new command: "thread find [REGEXP]".
2445 It finds the thread id whose name, target id, or thread extra info
2446 matches the given regular expression.
2448 * The "catch syscall" command now works on mips*-linux* targets.
2450 * The -data-disassemble MI command now supports modes 2 and 3 for
2451 dumping the instruction opcodes.
2453 * New command line options
2455 -data-directory DIR Specify DIR as the "data-directory".
2456 This is mostly for testing purposes.
2458 * The "maint set python auto-load on|off" command has been renamed to
2459 "set auto-load-scripts on|off".
2461 * GDB has a new command: "set directories".
2462 It is like the "dir" command except that it replaces the
2463 source path list instead of augmenting it.
2465 * GDB now understands thread names.
2467 On GNU/Linux, "info threads" will display the thread name as set by
2468 prctl or pthread_setname_np.
2470 There is also a new command, "thread name", which can be used to
2471 assign a name internally for GDB to display.
2474 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2475 has been integrated into GDB.
2479 ** The function gdb.Write now accepts an optional keyword 'stream'.
2480 This keyword, when provided, will direct the output to either
2481 stdout, stderr, or GDB's logging output.
2483 ** Parameters can now be be sub-classed in Python, and in particular
2484 you may implement the get_set_doc and get_show_doc functions.
2485 This improves how Parameter set/show documentation is processed
2486 and allows for more dynamic content.
2488 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2489 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2490 have an is_valid method.
2492 ** Breakpoints can now be sub-classed in Python, and in particular
2493 you may implement a 'stop' function that is executed each time
2494 the inferior reaches that breakpoint.
2496 ** New function gdb.lookup_global_symbol looks up a global symbol.
2498 ** GDB values in Python are now callable if the value represents a
2499 function. For example, if 'some_value' represents a function that
2500 takes two integer parameters and returns a value, you can call
2501 that function like so:
2503 result = some_value (10,20)
2505 ** Module gdb.types has been added.
2506 It contains a collection of utilities for working with gdb.Types objects:
2507 get_basic_type, has_field, make_enum_dict.
2509 ** Module gdb.printing has been added.
2510 It contains utilities for writing and registering pretty-printers.
2511 New classes: PrettyPrinter, SubPrettyPrinter,
2512 RegexpCollectionPrettyPrinter.
2513 New function: register_pretty_printer.
2515 ** New commands "info pretty-printers", "enable pretty-printer" and
2516 "disable pretty-printer" have been added.
2518 ** gdb.parameter("directories") is now available.
2520 ** New function gdb.newest_frame returns the newest frame in the
2523 ** The gdb.InferiorThread class has a new "name" attribute. This
2524 holds the thread's name.
2526 ** Python Support for Inferior events.
2527 Python scripts can add observers to be notified of events
2528 occurring in the process being debugged.
2529 The following events are currently supported:
2530 - gdb.events.cont Continue event.
2531 - gdb.events.exited Inferior exited event.
2532 - gdb.events.stop Signal received, and Breakpoint hit events.
2536 ** GDB now puts template parameters in scope when debugging in an
2537 instantiation. For example, if you have:
2539 template<int X> int func (void) { return X; }
2541 then if you step into func<5>, "print X" will show "5". This
2542 feature requires proper debuginfo support from the compiler; it
2543 was added to GCC 4.5.
2545 ** The motion commands "next", "finish", "until", and "advance" now
2546 work better when exceptions are thrown. In particular, GDB will
2547 no longer lose control of the inferior; instead, the GDB will
2548 stop the inferior at the point at which the exception is caught.
2549 This functionality requires a change in the exception handling
2550 code that was introduced in GCC 4.5.
2552 * GDB now follows GCC's rules on accessing volatile objects when
2553 reading or writing target state during expression evaluation.
2554 One notable difference to prior behavior is that "print x = 0"
2555 no longer generates a read of x; the value of the assignment is
2556 now always taken directly from the value being assigned.
2558 * GDB now has some support for using labels in the program's source in
2559 linespecs. For instance, you can use "advance label" to continue
2560 execution to a label.
2562 * GDB now has support for reading and writing a new .gdb_index
2563 section. This section holds a fast index of DWARF debugging
2564 information and can be used to greatly speed up GDB startup and
2565 operation. See the documentation for `save gdb-index' for details.
2567 * The "watch" command now accepts an optional "-location" argument.
2568 When used, this causes GDB to watch the memory referred to by the
2569 expression. Such a watchpoint is never deleted due to it going out
2572 * GDB now supports thread debugging of core dumps on GNU/Linux.
2574 GDB now activates thread debugging using the libthread_db library
2575 when debugging GNU/Linux core dumps, similarly to when debugging
2576 live processes. As a result, when debugging a core dump file, GDB
2577 is now able to display pthread_t ids of threads. For example, "info
2578 threads" shows the same output as when debugging the process when it
2579 was live. In earlier releases, you'd see something like this:
2582 * 1 LWP 6780 main () at main.c:10
2584 While now you see this:
2587 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2589 It is also now possible to inspect TLS variables when debugging core
2592 When debugging a core dump generated on a machine other than the one
2593 used to run GDB, you may need to point GDB at the correct
2594 libthread_db library with the "set libthread-db-search-path"
2595 command. See the user manual for more details on this command.
2597 * When natively debugging programs on PowerPC BookE processors running
2598 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2599 which stop execution of the inferior whenever it executes an instruction
2600 at any address within the specified range. See the "PowerPC Embedded"
2601 section in the user manual for more details.
2603 * New features in the GDB remote stub, GDBserver
2605 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2606 and i686 LynxOS (version 5.x).
2608 ** GDBserver is now supported on Blackfin Linux.
2610 * New native configurations
2612 ia64 HP-UX ia64-*-hpux*
2616 Analog Devices, Inc. Blackfin Processor bfin-*
2618 * Ada task switching is now supported on sparc-elf targets when
2619 debugging a program using the Ravenscar Profile. For more information,
2620 see the "Tasking Support when using the Ravenscar Profile" section
2621 in the GDB user manual.
2623 * Guile support was removed.
2625 * New features in the GNU simulator
2627 ** The --map-info flag lists all known core mappings.
2629 ** CFI flashes may be simulated via the "cfi" device.
2631 *** Changes in GDB 7.2
2633 * Shared library support for remote targets by default
2635 When GDB is configured for a generic, non-OS specific target, like
2636 for example, --target=arm-eabi or one of the many *-*-elf targets,
2637 GDB now queries remote stubs for loaded shared libraries using the
2638 `qXfer:libraries:read' packet. Previously, shared library support
2639 was always disabled for such configurations.
2643 ** Argument Dependent Lookup (ADL)
2645 In C++ ADL lookup directs function search to the namespaces of its
2646 arguments even if the namespace has not been imported.
2656 Here the compiler will search for `foo' in the namespace of 'b'
2657 and find A::foo. GDB now supports this. This construct is commonly
2658 used in the Standard Template Library for operators.
2660 ** Improved User Defined Operator Support
2662 In addition to member operators, GDB now supports lookup of operators
2663 defined in a namespace and imported with a `using' directive, operators
2664 defined in the global scope, operators imported implicitly from an
2665 anonymous namespace, and the ADL operators mentioned in the previous
2667 GDB now also supports proper overload resolution for all the previously
2668 mentioned flavors of operators.
2670 ** static const class members
2672 Printing of static const class members that are initialized in the
2673 class definition has been fixed.
2675 * Windows Thread Information Block access.
2677 On Windows targets, GDB now supports displaying the Windows Thread
2678 Information Block (TIB) structure. This structure is visible either
2679 by using the new command `info w32 thread-information-block' or, by
2680 dereferencing the new convenience variable named `$_tlb', a
2681 thread-specific pointer to the TIB. This feature is also supported
2682 when remote debugging using GDBserver.
2684 * Static tracepoints
2686 Static tracepoints are calls in the user program into a tracing
2687 library. One such library is a port of the LTTng kernel tracer to
2688 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2689 When debugging with GDBserver, GDB now supports combining the GDB
2690 tracepoint machinery with such libraries. For example: the user can
2691 use GDB to probe a static tracepoint marker (a call from the user
2692 program into the tracing library) with the new "strace" command (see
2693 "New commands" below). This creates a "static tracepoint" in the
2694 breakpoint list, that can be manipulated with the same feature set
2695 as fast and regular tracepoints. E.g., collect registers, local and
2696 global variables, collect trace state variables, and define
2697 tracepoint conditions. In addition, the user can collect extra
2698 static tracepoint marker specific data, by collecting the new
2699 $_sdata internal variable. When analyzing the trace buffer, you can
2700 inspect $_sdata like any other variable available to GDB. For more
2701 information, see the "Tracepoints" chapter in GDB user manual. New
2702 remote packets have been defined to support static tracepoints, see
2703 the "New remote packets" section below.
2705 * Better reconstruction of tracepoints after disconnected tracing
2707 GDB will attempt to download the original source form of tracepoint
2708 definitions when starting a trace run, and then will upload these
2709 upon reconnection to the target, resulting in a more accurate
2710 reconstruction of the tracepoints that are in use on the target.
2714 You can now exercise direct control over the ways that GDB can
2715 affect your program. For instance, you can disallow the setting of
2716 breakpoints, so that the program can run continuously (assuming
2717 non-stop mode). In addition, the "observer" variable is available
2718 to switch all of the different controls; in observer mode, GDB
2719 cannot affect the target's behavior at all, which is useful for
2720 tasks like diagnosing live systems in the field.
2722 * The new convenience variable $_thread holds the number of the
2725 * New remote packets
2729 Return the address of the Windows Thread Information Block of a given thread.
2733 In response to several of the tracepoint packets, the target may now
2734 also respond with a number of intermediate `qRelocInsn' request
2735 packets before the final result packet, to have GDB handle
2736 relocating an instruction to execute at a different address. This
2737 is particularly useful for stubs that support fast tracepoints. GDB
2738 reports support for this feature in the qSupported packet.
2742 List static tracepoint markers in the target program.
2746 List static tracepoint markers at a given address in the target
2749 qXfer:statictrace:read
2751 Read the static trace data collected (by a `collect $_sdata'
2752 tracepoint action). The remote stub reports support for this packet
2753 to gdb's qSupported query.
2757 Send the current settings of GDB's permission flags.
2761 Send part of the source (textual) form of a tracepoint definition,
2762 which includes location, conditional, and action list.
2764 * The source command now accepts a -s option to force searching for the
2765 script in the source search path even if the script name specifies
2768 * New features in the GDB remote stub, GDBserver
2770 - GDBserver now support tracepoints (including fast tracepoints, and
2771 static tracepoints). The feature is currently supported by the
2772 i386-linux and amd64-linux builds. See the "Tracepoints support
2773 in gdbserver" section in the manual for more information.
2775 GDBserver JIT compiles the tracepoint's conditional agent
2776 expression bytecode into native code whenever possible for low
2777 overhead dynamic tracepoints conditionals. For such tracepoints,
2778 an expression that examines program state is evaluated when the
2779 tracepoint is reached, in order to determine whether to capture
2780 trace data. If the condition is simple and false, processing the
2781 tracepoint finishes very quickly and no data is gathered.
2783 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2784 for static tracepoints support.
2786 - GDBserver now supports x86_64 Windows 64-bit debugging.
2788 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2789 it understands register description.
2791 * The --batch flag now disables pagination and queries.
2793 * X86 general purpose registers
2795 GDB now supports reading/writing byte, word and double-word x86
2796 general purpose registers directly. This means you can use, say,
2797 $ah or $ax to refer, respectively, to the byte register AH and
2798 16-bit word register AX that are actually portions of the 32-bit
2799 register EAX or 64-bit register RAX.
2801 * The `commands' command now accepts a range of breakpoints to modify.
2802 A plain `commands' following a command that creates multiple
2803 breakpoints affects all the breakpoints set by that command. This
2804 applies to breakpoints set by `rbreak', and also applies when a
2805 single `break' command creates multiple breakpoints (e.g.,
2806 breakpoints on overloaded c++ functions).
2808 * The `rbreak' command now accepts a filename specification as part of
2809 its argument, limiting the functions selected by the regex to those
2810 in the specified file.
2812 * Support for remote debugging Windows and SymbianOS shared libraries
2813 from Unix hosts has been improved. Non Windows GDB builds now can
2814 understand target reported file names that follow MS-DOS based file
2815 system semantics, such as file names that include drive letters and
2816 use the backslash character as directory separator. This makes it
2817 possible to transparently use the "set sysroot" and "set
2818 solib-search-path" on Unix hosts to point as host copies of the
2819 target's shared libraries. See the new command "set
2820 target-file-system-kind" described below, and the "Commands to
2821 specify files" section in the user manual for more information.
2825 eval template, expressions...
2826 Convert the values of one or more expressions under the control
2827 of the string template to a command line, and call it.
2829 set target-file-system-kind unix|dos-based|auto
2830 show target-file-system-kind
2831 Set or show the assumed file system kind for target reported file
2834 save breakpoints <filename>
2835 Save all current breakpoint definitions to a file suitable for use
2836 in a later debugging session. To read the saved breakpoint
2837 definitions, use the `source' command.
2839 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2842 info static-tracepoint-markers
2843 Display information about static tracepoint markers in the target.
2845 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2846 Define a static tracepoint by probing a marker at the given
2847 function, line, address, or marker ID.
2851 Enable and disable observer mode.
2853 set may-write-registers on|off
2854 set may-write-memory on|off
2855 set may-insert-breakpoints on|off
2856 set may-insert-tracepoints on|off
2857 set may-insert-fast-tracepoints on|off
2858 set may-interrupt on|off
2859 Set individual permissions for GDB effects on the target. Note that
2860 some of these settings can have undesirable or surprising
2861 consequences, particularly when changed in the middle of a session.
2862 For instance, disabling the writing of memory can prevent
2863 breakpoints from being inserted, cause single-stepping to fail, or
2864 even crash your program, if you disable after breakpoints have been
2865 inserted. However, GDB should not crash.
2867 set record memory-query on|off
2868 show record memory-query
2869 Control whether to stop the inferior if memory changes caused
2870 by an instruction cannot be recorded.
2875 The disassemble command now supports "start,+length" form of two arguments.
2879 ** GDB now provides a new directory location, called the python directory,
2880 where Python scripts written for GDB can be installed. The location
2881 of that directory is <data-directory>/python, where <data-directory>
2882 is the GDB data directory. For more details, see section `Scripting
2883 GDB using Python' in the manual.
2885 ** The GDB Python API now has access to breakpoints, symbols, symbol
2886 tables, program spaces, inferiors, threads and frame's code blocks.
2887 Additionally, GDB Parameters can now be created from the API, and
2888 manipulated via set/show in the CLI.
2890 ** New functions gdb.target_charset, gdb.target_wide_charset,
2891 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2893 ** New exception gdb.GdbError.
2895 ** Pretty-printers are now also looked up in the current program space.
2897 ** Pretty-printers can now be individually enabled and disabled.
2899 ** GDB now looks for names of Python scripts to auto-load in a
2900 special section named `.debug_gdb_scripts', in addition to looking
2901 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2903 * Tracepoint actions were unified with breakpoint commands. In particular,
2904 there are no longer differences in "info break" output for breakpoints and
2905 tracepoints and the "commands" command can be used for both tracepoints and
2906 regular breakpoints.
2910 ARM Symbian arm*-*-symbianelf*
2912 * D language support.
2913 GDB now supports debugging programs written in the D programming
2916 * GDB now supports the extended ptrace interface for PowerPC which is
2917 available since Linux kernel version 2.6.34. This automatically enables
2918 any hardware breakpoints and additional hardware watchpoints available in
2919 the processor. The old ptrace interface exposes just one hardware
2920 watchpoint and no hardware breakpoints.
2922 * GDB is now able to use the Data Value Compare (DVC) register available on
2923 embedded PowerPC processors to implement in hardware simple watchpoint
2924 conditions of the form:
2926 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2928 This works in native GDB running on Linux kernels with the extended ptrace
2929 interface mentioned above.
2931 *** Changes in GDB 7.1
2935 ** Namespace Support
2937 GDB now supports importing of namespaces in C++. This enables the
2938 user to inspect variables from imported namespaces. Support for
2939 namepace aliasing has also been added. So, if a namespace is
2940 aliased in the current scope (e.g. namepace C=A; ) the user can
2941 print variables using the alias (e.g. (gdb) print C::x).
2945 All known bugs relating to the printing of virtual base class were
2946 fixed. It is now possible to call overloaded static methods using a
2951 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2952 and reinterpret_cast<> are now handled by the C++ expression parser.
2956 Xilinx MicroBlaze microblaze-*-*
2961 Xilinx MicroBlaze microblaze
2964 * Multi-program debugging.
2966 GDB now has support for multi-program (a.k.a. multi-executable or
2967 multi-exec) debugging. This allows for debugging multiple inferiors
2968 simultaneously each running a different program under the same GDB
2969 session. See "Debugging Multiple Inferiors and Programs" in the
2970 manual for more information. This implied some user visible changes
2971 in the multi-inferior support. For example, "info inferiors" now
2972 lists inferiors that are not running yet or that have exited
2973 already. See also "New commands" and "New options" below.
2975 * New tracing features
2977 GDB's tracepoint facility now includes several new features:
2979 ** Trace state variables
2981 GDB tracepoints now include support for trace state variables, which
2982 are variables managed by the target agent during a tracing
2983 experiment. They are useful for tracepoints that trigger each
2984 other, so for instance one tracepoint can count hits in a variable,
2985 and then a second tracepoint has a condition that is true when the
2986 count reaches a particular value. Trace state variables share the
2987 $-syntax of GDB convenience variables, and can appear in both
2988 tracepoint actions and condition expressions. Use the "tvariable"
2989 command to create, and "info tvariables" to view; see "Trace State
2990 Variables" in the manual for more detail.
2994 GDB now includes an option for defining fast tracepoints, which
2995 targets may implement more efficiently, such as by installing a jump
2996 into the target agent rather than a trap instruction. The resulting
2997 speedup can be by two orders of magnitude or more, although the
2998 tradeoff is that some program locations on some target architectures
2999 might not allow fast tracepoint installation, for instance if the
3000 instruction to be replaced is shorter than the jump. To request a
3001 fast tracepoint, use the "ftrace" command, with syntax identical to
3002 the regular trace command.
3004 ** Disconnected tracing
3006 It is now possible to detach GDB from the target while it is running
3007 a trace experiment, then reconnect later to see how the experiment
3008 is going. In addition, a new variable disconnected-tracing lets you
3009 tell the target agent whether to continue running a trace if the
3010 connection is lost unexpectedly.
3014 GDB now has the ability to save the trace buffer into a file, and
3015 then use that file as a target, similarly to you can do with
3016 corefiles. You can select trace frames, print data that was
3017 collected in them, and use tstatus to display the state of the
3018 tracing run at the moment that it was saved. To create a trace
3019 file, use "tsave <filename>", and to use it, do "target tfile
3022 ** Circular trace buffer
3024 You can ask the target agent to handle the trace buffer as a
3025 circular buffer, discarding the oldest trace frames to make room for
3026 newer ones, by setting circular-trace-buffer to on. This feature may
3027 not be available for all target agents.
3032 The disassemble command, when invoked with two arguments, now requires
3033 the arguments to be comma-separated.
3036 The info variables command now displays variable definitions. Files
3037 which only declare a variable are not shown.
3040 The source command is now capable of sourcing Python scripts.
3041 This feature is dependent on the debugger being build with Python
3044 Related to this enhancement is also the introduction of a new command
3045 "set script-extension" (see below).
3047 * New commands (for set/show, see "New options" below)
3049 record save [<FILENAME>]
3050 Save a file (in core file format) containing the process record
3051 execution log for replay debugging at a later time.
3053 record restore <FILENAME>
3054 Restore the process record execution log that was saved at an
3055 earlier time, for replay debugging.
3057 add-inferior [-copies <N>] [-exec <FILENAME>]
3060 clone-inferior [-copies <N>] [ID]
3061 Make a new inferior ready to execute the same program another
3062 inferior has loaded.
3067 maint info program-spaces
3068 List the program spaces loaded into GDB.
3070 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3071 show remote interrupt-sequence
3072 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3073 as the sequence to the remote target in order to interrupt the execution.
3074 Ctrl-C is a default. Some system prefers BREAK which is high level of
3075 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3076 Magic SysRq g. It is BREAK signal and character 'g'.
3078 set remote interrupt-on-connect [on | off]
3079 show remote interrupt-on-connect
3080 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3081 remote target when gdb connects to it. This is needed when you debug
3084 set remotebreak [on | off]
3086 Deprecated. Use "set/show remote interrupt-sequence" instead.
3088 tvariable $NAME [ = EXP ]
3089 Create or modify a trace state variable.
3092 List trace state variables and their values.
3094 delete tvariable $NAME ...
3095 Delete one or more trace state variables.
3098 Evaluate the given expressions without collecting anything into the
3099 trace buffer. (Valid in tracepoint actions only.)
3101 ftrace FN / FILE:LINE / *ADDR
3102 Define a fast tracepoint at the given function, line, or address.
3104 * New expression syntax
3106 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3107 GDB now parses 0b101010 identically with 42.
3111 set follow-exec-mode new|same
3112 show follow-exec-mode
3113 Control whether GDB reuses the same inferior across an exec call or
3114 creates a new one. This is useful to be able to restart the old
3115 executable after the inferior having done an exec call.
3117 set default-collect EXPR, ...
3118 show default-collect
3119 Define a list of expressions to be collected at each tracepoint.
3120 This is a useful way to ensure essential items are not overlooked,
3121 such as registers or a critical global variable.
3123 set disconnected-tracing
3124 show disconnected-tracing
3125 If set to 1, the target is instructed to continue tracing if it
3126 loses its connection to GDB. If 0, the target is to stop tracing
3129 set circular-trace-buffer
3130 show circular-trace-buffer
3131 If set to on, the target is instructed to use a circular trace buffer
3132 and discard the oldest trace frames instead of stopping the trace due
3133 to a full trace buffer. If set to off, the trace stops when the buffer
3134 fills up. Some targets may not support this.
3136 set script-extension off|soft|strict
3137 show script-extension
3138 If set to "off", the debugger does not perform any script language
3139 recognition, and all sourced files are assumed to be GDB scripts.
3140 If set to "soft" (the default), files are sourced according to
3141 filename extension, falling back to GDB scripts if the first
3143 If set to "strict", files are sourced according to filename extension.
3145 set ada trust-PAD-over-XVS on|off
3146 show ada trust-PAD-over-XVS
3147 If off, activate a workaround against a bug in the debugging information
3148 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3149 the GCC sources for more information about the GNAT encoding and
3150 PAD types in particular). It is always safe to set this option to
3151 off, but this introduces a slight performance penalty. The default
3154 * Python API Improvements
3156 ** GDB provides the new class gdb.LazyString. This is useful in
3157 some pretty-printing cases. The new method gdb.Value.lazy_string
3158 provides a simple way to create objects of this type.
3160 ** The fields returned by gdb.Type.fields now have an
3161 `is_base_class' attribute.
3163 ** The new method gdb.Type.range returns the range of an array type.
3165 ** The new method gdb.parse_and_eval can be used to parse and
3166 evaluate an expression.
3168 * New remote packets
3171 Define a trace state variable.
3174 Get the current value of a trace state variable.
3177 Set desired tracing behavior upon disconnection.
3180 Set the trace buffer to be linear or circular.
3183 Get data about the tracepoints currently in use.
3187 Process record now works correctly with hardware watchpoints.
3189 Multiple bug fixes have been made to the mips-irix port, making it
3190 much more reliable. In particular:
3191 - Debugging threaded applications is now possible again. Previously,
3192 GDB would hang while starting the program, or while waiting for
3193 the program to stop at a breakpoint.
3194 - Attaching to a running process no longer hangs.
3195 - An error occurring while loading a core file has been fixed.
3196 - Changing the value of the PC register now works again. This fixes
3197 problems observed when using the "jump" command, or when calling
3198 a function from GDB, or even when assigning a new value to $pc.
3199 - With the "finish" and "return" commands, the return value for functions
3200 returning a small array is now correctly printed.
3201 - It is now possible to break on shared library code which gets executed
3202 during a shared library init phase (code executed while executing
3203 their .init section). Previously, the breakpoint would have no effect.
3204 - GDB is now able to backtrace through the signal handler for
3205 non-threaded programs.
3207 PIE (Position Independent Executable) programs debugging is now supported.
3208 This includes debugging execution of PIC (Position Independent Code) shared
3209 libraries although for that, it should be possible to run such libraries as an
3212 *** Changes in GDB 7.0
3214 * GDB now has an interface for JIT compilation. Applications that
3215 dynamically generate code can create symbol files in memory and register
3216 them with GDB. For users, the feature should work transparently, and
3217 for JIT developers, the interface is documented in the GDB manual in the
3218 "JIT Compilation Interface" chapter.
3220 * Tracepoints may now be conditional. The syntax is as for
3221 breakpoints; either an "if" clause appended to the "trace" command,
3222 or the "condition" command is available. GDB sends the condition to
3223 the target for evaluation using the same bytecode format as is used
3224 for tracepoint actions.
3226 * The disassemble command now supports: an optional /r modifier, print the
3227 raw instructions in hex as well as in symbolic form, and an optional /m
3228 modifier to print mixed source+assembly.
3230 * Process record and replay
3232 In a architecture environment that supports ``process record and
3233 replay'', ``process record and replay'' target can record a log of
3234 the process execution, and replay it with both forward and reverse
3237 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3238 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3239 set execution-direction {forward|reverse}, for targets that support
3242 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3243 feature is available with a native GDB running on kernel version
3246 * GDB now has support for multi-byte and wide character sets on the
3247 target. Strings whose character type is wchar_t, char16_t, or
3248 char32_t are now correctly printed. GDB supports wide- and unicode-
3249 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3250 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3251 `printf'. This feature requires iconv to work properly; if your
3252 system does not have a working iconv, GDB can use GNU libiconv. See
3253 the installation instructions for more information.
3255 * GDB now supports automatic retrieval of shared library files from
3256 remote targets. To use this feature, specify a system root that begins
3257 with the `remote:' prefix, either via the `set sysroot' command or via
3258 the `--with-sysroot' configure-time option.
3260 * "info sharedlibrary" now takes an optional regex of libraries to show,
3261 and it now reports if a shared library has no debugging information.
3263 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3264 now complete on file names.
3266 * When completing in expressions, gdb will attempt to limit
3267 completions to allowable structure or union fields, where appropriate.
3268 For instance, consider:
3270 # struct example { int f1; double f2; };
3271 # struct example variable;
3274 If the user types TAB at the end of this command line, the available
3275 completions will be "f1" and "f2".
3277 * Inlined functions are now supported. They show up in backtraces, and
3278 the "step", "next", and "finish" commands handle them automatically.
3280 * GDB now supports the token-splicing (##) and stringification (#)
3281 operators when expanding macros. It also supports variable-arity
3284 * GDB now supports inspecting extra signal information, exported by
3285 the new $_siginfo convenience variable. The feature is currently
3286 implemented on linux ARM, i386 and amd64.
3288 * GDB can now display the VFP floating point registers and NEON vector
3289 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3290 can provide these registers (requires Linux 2.6.30 or later). Remote
3291 and simulator targets may also provide them.
3293 * New remote packets
3296 Search memory for a sequence of bytes.
3299 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3300 operation over reliable transport links. Use of this packet is
3301 controlled by the `set remote noack-packet' command.
3304 Kill the process with the specified process ID. Use this in preference
3305 to `k' when multiprocess protocol extensions are supported.
3308 Obtains additional operating system information
3312 Read or write additional signal information.
3314 * Removed remote protocol undocumented extension
3316 An undocumented extension to the remote protocol's `S' stop reply
3317 packet that permited the stub to pass a process id was removed.
3318 Remote servers should use the `T' stop reply packet instead.
3320 * GDB now supports multiple function calling conventions according to the
3321 DWARF-2 DW_AT_calling_convention function attribute.
3323 * The SH target utilizes the aforementioned change to distinguish between gcc
3324 and Renesas calling convention. It also adds the new CLI commands
3325 `set/show sh calling-convention'.
3327 * GDB can now read compressed debug sections, as produced by GNU gold
3328 with the --compress-debug-sections=zlib flag.
3330 * 64-bit core files are now supported on AIX.
3332 * Thread switching is now supported on Tru64.
3334 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3335 which will be allocated using malloc later in program execution.
3337 * The qXfer:libraries:read remote procotol packet now allows passing a
3338 list of section offsets.
3340 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3341 conditions handling signals delivered during attach or thread creation
3342 have also been fixed.
3344 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3345 From the user's standpoint, all unqualified instances of True and False
3346 are treated as the standard definitions, regardless of context.
3348 * GDB now parses C++ symbol and type names more flexibly. For
3351 template<typename T> class C { };
3354 GDB will now correctly handle all of:
3356 ptype C<char const *>
3357 ptype C<char const*>
3358 ptype C<const char *>
3359 ptype C<const char*>
3361 * New features in the GDB remote stub, gdbserver
3363 - The "--wrapper" command-line argument tells gdbserver to use a
3364 wrapper program to launch programs for debugging.
3366 - On PowerPC and S/390 targets, it is now possible to use a single
3367 gdbserver executable to debug both 32-bit and 64-bit programs.
3368 (This requires gdbserver itself to be built as a 64-bit executable.)
3370 - gdbserver uses the new noack protocol mode for TCP connections to
3371 reduce communications latency, if also supported and enabled in GDB.
3373 - Support for the sparc64-linux-gnu target is now included in
3376 - The amd64-linux build of gdbserver now supports debugging both
3377 32-bit and 64-bit programs.
3379 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3380 now support hardware watchpoints, and will use them automatically
3385 GDB now has support for scripting using Python. Whether this is
3386 available is determined at configure time.
3388 New GDB commands can now be written in Python.
3390 * Ada tasking support
3392 Ada tasks can now be inspected in GDB. The following commands have
3396 Print the list of Ada tasks.
3398 Print detailed information about task number N.
3400 Print the task number of the current task.
3402 Switch the context of debugging to task number N.
3404 * Support for user-defined prefixed commands. The "define" command can
3405 add new commands to existing prefixes, e.g. "target".
3407 * Multi-inferior, multi-process debugging.
3409 GDB now has generalized support for multi-inferior debugging. See
3410 "Debugging Multiple Inferiors" in the manual for more information.
3411 Although availability still depends on target support, the command
3412 set is more uniform now. The GNU/Linux specific multi-forks support
3413 has been migrated to this new framework. This implied some user
3414 visible changes; see "New commands" and also "Removed commands"
3417 * Target descriptions can now describe the target OS ABI. See the
3418 "Target Description Format" section in the user manual for more
3421 * Target descriptions can now describe "compatible" architectures
3422 to indicate that the target can execute applications for a different
3423 architecture in addition to those for the main target architecture.
3424 See the "Target Description Format" section in the user manual for
3427 * Multi-architecture debugging.
3429 GDB now includes general supports for debugging applications on
3430 hybrid systems that use more than one single processor architecture
3431 at the same time. Each such hybrid architecture still requires
3432 specific support to be added. The only hybrid architecture supported
3433 in this version of GDB is the Cell Broadband Engine.
3435 * GDB now supports integrated debugging of Cell/B.E. applications that
3436 use both the PPU and SPU architectures. To enable support for hybrid
3437 Cell/B.E. debugging, you need to configure GDB to support both the
3438 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3439 --enable-targets configure option.
3441 * Non-stop mode debugging.
3443 For some targets, GDB now supports an optional mode of operation in
3444 which you can examine stopped threads while other threads continue
3445 to execute freely. This is referred to as non-stop mode, with the
3446 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3447 section in the user manual for more information.
3449 To be able to support remote non-stop debugging, a remote stub needs
3450 to implement the non-stop mode remote protocol extensions, as
3451 described in the "Remote Non-Stop" section of the user manual. The
3452 GDB remote stub, gdbserver, has been adjusted to support these
3453 extensions on linux targets.
3455 * New commands (for set/show, see "New options" below)
3457 catch syscall [NAME(S) | NUMBER(S)]
3458 Catch system calls. Arguments, which should be names of system
3459 calls or their numbers, mean catch only those syscalls. Without
3460 arguments, every syscall will be caught. When the inferior issues
3461 any of the specified syscalls, GDB will stop and announce the system
3462 call, both when it is called and when its call returns. This
3463 feature is currently available with a native GDB running on the
3464 Linux Kernel, under the following architectures: x86, x86_64,
3465 PowerPC and PowerPC64.
3467 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3469 Search memory for a sequence of bytes.
3471 maint set python print-stack
3472 maint show python print-stack
3473 Show a stack trace when an error is encountered in a Python script.
3476 Invoke CODE by passing it to the Python interpreter.
3481 These allow macros to be defined, undefined, and listed
3485 Show operating system information about processes.
3488 List the inferiors currently under GDB's control.
3491 Switch focus to inferior number NUM.
3494 Detach from inferior number NUM.
3497 Kill inferior number NUM.
3501 set spu stop-on-load
3502 show spu stop-on-load
3503 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3505 set spu auto-flush-cache
3506 show spu auto-flush-cache
3507 Control whether to automatically flush the software-managed cache
3508 during Cell/B.E. debugging.
3510 set sh calling-convention
3511 show sh calling-convention
3512 Control the calling convention used when calling SH target functions.
3515 show debug timestamp
3516 Control display of timestamps with GDB debugging output.
3518 set disassemble-next-line
3519 show disassemble-next-line
3520 Control display of disassembled source lines or instructions when
3523 set remote noack-packet
3524 show remote noack-packet
3525 Set/show the use of remote protocol QStartNoAckMode packet. See above
3526 under "New remote packets."
3528 set remote query-attached-packet
3529 show remote query-attached-packet
3530 Control use of remote protocol `qAttached' (query-attached) packet.
3532 set remote read-siginfo-object
3533 show remote read-siginfo-object
3534 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3537 set remote write-siginfo-object
3538 show remote write-siginfo-object
3539 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3542 set remote reverse-continue
3543 show remote reverse-continue
3544 Control use of remote protocol 'bc' (reverse-continue) packet.
3546 set remote reverse-step
3547 show remote reverse-step
3548 Control use of remote protocol 'bs' (reverse-step) packet.
3550 set displaced-stepping
3551 show displaced-stepping
3552 Control displaced stepping mode. Displaced stepping is a way to
3553 single-step over breakpoints without removing them from the debuggee.
3554 Also known as "out-of-line single-stepping".
3557 show debug displaced
3558 Control display of debugging info for displaced stepping.
3560 maint set internal-error
3561 maint show internal-error
3562 Control what GDB does when an internal error is detected.
3564 maint set internal-warning
3565 maint show internal-warning
3566 Control what GDB does when an internal warning is detected.
3571 Use a wrapper program to launch programs for debugging.
3573 set multiple-symbols (all|ask|cancel)
3574 show multiple-symbols
3575 The value of this variable can be changed to adjust the debugger behavior
3576 when an expression or a breakpoint location contains an ambiguous symbol
3577 name (an overloaded function name, for instance).
3579 set breakpoint always-inserted
3580 show breakpoint always-inserted
3581 Keep breakpoints always inserted in the target, as opposed to inserting
3582 them when resuming the target, and removing them when the target stops.
3583 This option can improve debugger performance on slow remote targets.
3585 set arm fallback-mode (arm|thumb|auto)
3586 show arm fallback-mode
3587 set arm force-mode (arm|thumb|auto)
3589 These commands control how ARM GDB determines whether instructions
3590 are ARM or Thumb. The default for both settings is auto, which uses
3591 the current CPSR value for instructions without symbols; previous
3592 versions of GDB behaved as if "set arm fallback-mode arm".
3594 set disable-randomization
3595 show disable-randomization
3596 Standalone programs run with the virtual address space randomization enabled
3597 by default on some platforms. This option keeps the addresses stable across
3598 multiple debugging sessions.
3602 Control whether other threads are stopped or not when some thread hits
3607 Requests that asynchronous execution is enabled in the target, if available.
3608 In this case, it's possible to resume target in the background, and interact
3609 with GDB while the target is running. "show target-async" displays the
3610 current state of asynchronous execution of the target.
3612 set target-wide-charset
3613 show target-wide-charset
3614 The target-wide-charset is the name of the character set that GDB
3615 uses when printing characters whose type is wchar_t.
3617 set tcp auto-retry (on|off)
3619 set tcp connect-timeout
3620 show tcp connect-timeout
3621 These commands allow GDB to retry failed TCP connections to a remote stub
3622 with a specified timeout period; this is useful if the stub is launched
3623 in parallel with GDB but may not be ready to accept connections immediately.
3625 set libthread-db-search-path
3626 show libthread-db-search-path
3627 Control list of directories which GDB will search for appropriate
3630 set schedule-multiple (on|off)
3631 show schedule-multiple
3632 Allow GDB to resume all threads of all processes or only threads of
3633 the current process.
3637 Use more aggressive caching for accesses to the stack. This improves
3638 performance of remote debugging (particularly backtraces) without
3639 affecting correctness.
3641 set interactive-mode (on|off|auto)
3642 show interactive-mode
3643 Control whether GDB runs in interactive mode (on) or not (off).
3644 When in interactive mode, GDB waits for the user to answer all
3645 queries. Otherwise, GDB does not wait and assumes the default
3646 answer. When set to auto (the default), GDB determines which
3647 mode to use based on the stdin settings.
3652 For program forks, this is replaced by the new more generic `info
3653 inferiors' command. To list checkpoints, you can still use the
3654 `info checkpoints' command, which was an alias for the `info forks'
3658 Replaced by the new `inferior' command. To switch between
3659 checkpoints, you can still use the `restart' command, which was an
3660 alias for the `fork' command.
3663 This is removed, since some targets don't have a notion of
3664 processes. To switch between processes, you can still use the
3665 `inferior' command using GDB's own inferior number.
3668 For program forks, this is replaced by the new more generic `kill
3669 inferior' command. To delete a checkpoint, you can still use the
3670 `delete checkpoint' command, which was an alias for the `delete
3674 For program forks, this is replaced by the new more generic `detach
3675 inferior' command. To detach a checkpoint, you can still use the
3676 `detach checkpoint' command, which was an alias for the `detach
3679 * New native configurations
3681 x86/x86_64 Darwin i[34567]86-*-darwin*
3683 x86_64 MinGW x86_64-*-mingw*
3687 Lattice Mico32 lm32-*
3688 x86 DICOS i[34567]86-*-dicos*
3689 x86_64 DICOS x86_64-*-dicos*
3692 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3693 (mingw32ce) debugging.
3699 These commands were actually not implemented on any target.
3701 *** Changes in GDB 6.8
3703 * New native configurations
3705 NetBSD/hppa hppa*-*netbsd*
3706 Xtensa GNU/Linux xtensa*-*-linux*
3710 NetBSD/hppa hppa*-*-netbsd*
3711 Xtensa GNU/Lunux xtensa*-*-linux*
3713 * Change in command line behavior -- corefiles vs. process ids.
3715 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3716 attaching to process NUMBER fails, GDB no longer attempts to open a
3717 core file named NUMBER. Attaching to a program using the -c option
3718 is no longer supported. Instead, use the '-p' or '--pid' options.
3720 * GDB can now be built as a native debugger for debugging Windows x86
3721 (mingw32) Portable Executable (PE) programs.
3723 * Pending breakpoints no longer change their number when their address
3726 * GDB now supports breakpoints with multiple locations,
3727 including breakpoints on C++ constructors, inside C++ templates,
3728 and in inlined functions.
3730 * GDB's ability to debug optimized code has been improved. GDB more
3731 accurately identifies function bodies and lexical blocks that occupy
3732 more than one contiguous range of addresses.
3734 * Target descriptions can now describe registers for PowerPC.
3736 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3737 registers on PowerPC targets.
3739 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3740 targets even when the libthread_db library is not available.
3742 * The GDB remote stub, gdbserver, now supports the new file transfer
3743 commands (remote put, remote get, and remote delete).
3745 * The GDB remote stub, gdbserver, now supports run and attach in
3746 extended-remote mode.
3748 * hppa*64*-*-hpux11* target broken
3749 The debugger is unable to start a program and fails with the following
3750 error: "Error trying to get information about dynamic linker".
3751 The gdb-6.7 release is also affected.
3753 * GDB now supports the --enable-targets= configure option to allow
3754 building a single GDB executable that supports multiple remote
3755 target architectures.
3757 * GDB now supports debugging C and C++ programs which use the
3758 Decimal Floating Point extension. In addition, the PowerPC target
3759 now has a set of pseudo-registers to inspect decimal float values
3760 stored in two consecutive float registers.
3762 * The -break-insert MI command can optionally create pending
3765 * Improved support for debugging Ada
3766 Many improvements to the Ada language support have been made. These
3768 - Better support for Ada2005 interface types
3769 - Improved handling of arrays and slices in general
3770 - Better support for Taft-amendment types
3771 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3773 - Improved command completion in Ada
3776 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3781 set print frame-arguments (all|scalars|none)
3782 show print frame-arguments
3783 The value of this variable can be changed to control which argument
3784 values should be printed by the debugger when displaying a frame.
3789 Transfer files to and from a remote target, and delete remote files.
3796 Transfer files to and from a remote target, and delete remote files.
3798 * New remote packets
3805 Open, close, read, write, and delete files on the remote system.
3808 Attach to an existing process on the remote system, in extended-remote
3812 Run a new process on the remote system, in extended-remote mode.
3814 *** Changes in GDB 6.7
3816 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3817 bfd, libiberty and opcodes, as revealed by static analysis donated by
3818 Coverity, Inc. (http://scan.coverity.com).
3820 * When looking up multiply-defined global symbols, GDB will now prefer the
3821 symbol definition in the current shared library if it was built using the
3822 -Bsymbolic linker option.
3824 * When the Text User Interface (TUI) is not configured, GDB will now
3825 recognize the -tui command-line option and print a message that the TUI
3828 * The GDB remote stub, gdbserver, now has lower overhead for high
3829 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3831 * GDB for MIPS targets now autodetects whether a remote target provides
3832 32-bit or 64-bit register values.
3834 * Support for C++ member pointers has been improved.
3836 * GDB now understands XML target descriptions, which specify the
3837 target's overall architecture. GDB can read a description from
3838 a local file or over the remote serial protocol.
3840 * Vectors of single-byte data use a new integer type which is not
3841 automatically displayed as character or string data.
3843 * The /s format now works with the print command. It displays
3844 arrays of single-byte integers and pointers to single-byte integers
3847 * Target descriptions can now describe target-specific registers,
3848 for architectures which have implemented the support (currently
3849 only ARM, M68K, and MIPS).
3851 * GDB and the GDB remote stub, gdbserver, now support the XScale
3854 * The GDB remote stub, gdbserver, has been updated to support
3855 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3856 has been rewritten to use the standard GDB remote protocol.
3858 * GDB can now step into C++ functions which are called through thunks.
3860 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3862 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3863 layout. It also supports a TextSeg= and DataSeg= response when only
3864 segment base addresses (rather than offsets) are available.
3866 * The /i format now outputs any trailing branch delay slot instructions
3867 immediately following the last instruction within the count specified.
3869 * The GDB remote protocol "T" stop reply packet now supports a
3870 "library" response. Combined with the new "qXfer:libraries:read"
3871 packet, this response allows GDB to debug shared libraries on targets
3872 where the operating system manages the list of loaded libraries (e.g.
3873 Windows and SymbianOS).
3875 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3876 (DLLs) on Windows and Windows CE targets.
3878 * GDB now supports a faster verification that a .debug file matches its binary
3879 according to its build-id signature, if the signature is present.
3885 Enable or disable hardware flow control (RTS/CTS) on the serial port
3886 when debugging using remote targets.
3888 set mem inaccessible-by-default
3889 show mem inaccessible-by-default
3890 If the target supplies a memory map, for instance via the remote
3891 protocol's "qXfer:memory-map:read" packet, setting this variable
3892 prevents GDB from accessing memory outside the memory map. This
3893 is useful for targets with memory mapped registers or which react
3894 badly to accesses of unmapped address space.
3896 set breakpoint auto-hw
3897 show breakpoint auto-hw
3898 If the target supplies a memory map, for instance via the remote
3899 protocol's "qXfer:memory-map:read" packet, setting this variable
3900 lets GDB use hardware breakpoints automatically for memory regions
3901 where it can not use software breakpoints. This covers both the
3902 "break" command and internal breakpoints used for other commands
3903 including "next" and "finish".
3906 catch exception unhandled
3907 Stop the program execution when Ada exceptions are raised.
3910 Stop the program execution when an Ada assertion failed.
3914 Set an alternate system root for target files. This is a more
3915 general version of "set solib-absolute-prefix", which is now
3916 an alias to "set sysroot".
3919 Provide extended SPU facility status information. This set of
3920 commands is available only when debugging the Cell/B.E. SPU
3923 * New native configurations
3925 OpenBSD/sh sh*-*openbsd*
3928 unset tdesc filename
3930 Use the specified local file as an XML target description, and do
3931 not query the target for its built-in description.
3935 OpenBSD/sh sh*-*-openbsd*
3936 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3937 Toshiba Media Processor mep-elf
3939 * New remote packets
3942 Ignore the specified signals; pass them directly to the debugged program
3943 without stopping other threads or reporting them to GDB.
3945 qXfer:features:read:
3946 Read an XML target description from the target, which describes its
3951 Read or write contents of an spufs file on the target system. These
3952 packets are available only on the Cell/B.E. SPU architecture.
3954 qXfer:libraries:read:
3955 Report the loaded shared libraries. Combined with new "T" packet
3956 response, this packet allows GDB to debug shared libraries on
3957 targets where the operating system manages the list of loaded
3958 libraries (e.g. Windows and SymbianOS).
3962 Support for these obsolete configurations has been removed.
3970 i[34567]86-*-lynxos*
3971 i[34567]86-*-netware*
3972 i[34567]86-*-sco3.2v5*
3973 i[34567]86-*-sco3.2v4*
3975 i[34567]86-*-sysv4.2*
3978 i[34567]86-*-unixware2*
3979 i[34567]86-*-unixware*
3988 * Other removed features
3995 Various m68k-only ROM monitors.
4002 Various Renesas ROM monitors and debugging interfaces for SH and
4007 Support for a Macraigor serial interface to on-chip debugging.
4008 GDB does not directly support the newer parallel or USB
4013 A debug information format. The predecessor to DWARF 2 and
4014 DWARF 3, which are still supported.
4016 Support for the HP aCC compiler on HP-UX/PA-RISC
4018 SOM-encapsulated symbolic debugging information, automatic
4019 invocation of pxdb, and the aCC custom C++ ABI. This does not
4020 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4021 with aCC can still be debugged on an assembly level.
4023 MIPS ".pdr" sections
4025 A MIPS-specific format used to describe stack frame layout
4026 in debugging information.
4030 GDB could work with an older version of Guile to debug
4031 the interpreter and Scheme programs running in it.
4033 set mips stack-arg-size
4034 set mips saved-gpreg-size
4036 Use "set mips abi" to control parameter passing for MIPS.
4038 *** Changes in GDB 6.6
4043 Cell Broadband Engine SPU spu-elf
4045 * GDB can now be configured as a cross-debugger targeting native Windows
4046 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4047 running on a Windows system over TCP/IP to debug Windows programs.
4049 * The GDB remote stub, gdbserver, has been updated to support Windows and
4050 Cygwin debugging. Both single-threaded and multi-threaded programs are
4053 * The "set trust-readonly-sections" command works again. This command was
4054 broken in GDB 6.3, 6.4, and 6.5.
4056 * The "load" command now supports writing to flash memory, if the remote
4057 stub provides the required support.
4059 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4060 longer requires symbolic debug information (e.g. DWARF-2).
4065 unset substitute-path
4066 show substitute-path
4067 Manage a list of substitution rules that GDB uses to rewrite the name
4068 of the directories where the sources are located. This can be useful
4069 for instance when the sources were moved to a different location
4070 between compilation and debugging.
4074 Print each CLI command as it is executed. Each command is prefixed with
4075 a number of `+' symbols representing the nesting depth.
4076 The source command now has a `-v' option to enable the same feature.
4080 The ARM Demon monitor support (RDP protocol, "target rdp").
4082 Kernel Object Display, an embedded debugging feature which only worked with
4083 an obsolete version of Cisco IOS.
4085 The 'set download-write-size' and 'show download-write-size' commands.
4087 * New remote packets
4090 Tell a stub about GDB client features, and request remote target features.
4091 The first feature implemented is PacketSize, which allows the target to
4092 specify the size of packets it can handle - to minimize the number of
4093 packets required and improve performance when connected to a remote
4097 Fetch an OS auxilliary vector from the remote stub. This packet is a
4098 more efficient replacement for qPart:auxv:read.
4100 qXfer:memory-map:read:
4101 Fetch a memory map from the remote stub, including information about
4102 RAM, ROM, and flash memory devices.
4107 Erase and program a flash memory device.
4109 * Removed remote packets
4112 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4113 used it, and only gdbserver implemented it.
4115 *** Changes in GDB 6.5
4119 Renesas M32C/M16C m32c-elf
4121 Morpho Technologies ms1 ms1-elf
4125 init-if-undefined Initialize a convenience variable, but
4126 only if it doesn't already have a value.
4128 The following commands are presently only implemented for native GNU/Linux:
4130 checkpoint Save a snapshot of the program state.
4132 restart <n> Return the program state to a
4133 previously saved state.
4135 info checkpoints List currently saved checkpoints.
4137 delete-checkpoint <n> Delete a previously saved checkpoint.
4139 set|show detach-on-fork Tell gdb whether to detach from a newly
4140 forked process, or to keep debugging it.
4142 info forks List forks of the user program that
4143 are available to be debugged.
4145 fork <n> Switch to debugging one of several
4146 forks of the user program that are
4147 available to be debugged.
4149 delete-fork <n> Delete a fork from the list of forks
4150 that are available to be debugged (and
4151 kill the forked process).
4153 detach-fork <n> Delete a fork from the list of forks
4154 that are available to be debugged (and
4155 allow the process to continue).
4159 Morpho Technologies ms2 ms1-elf
4161 * Improved Windows host support
4163 GDB now builds as a cross debugger hosted on i686-mingw32, including
4164 native console support, and remote communications using either
4165 network sockets or serial ports.
4167 * Improved Modula-2 language support
4169 GDB can now print most types in the Modula-2 syntax. This includes:
4170 basic types, set types, record types, enumerated types, range types,
4171 pointer types and ARRAY types. Procedure var parameters are correctly
4172 printed and hexadecimal addresses and character constants are also
4173 written in the Modula-2 syntax. Best results can be obtained by using
4174 GNU Modula-2 together with the -gdwarf-2 command line option.
4178 The ARM rdi-share module.
4180 The Netware NLM debug server.
4182 *** Changes in GDB 6.4
4184 * New native configurations
4186 OpenBSD/arm arm*-*-openbsd*
4187 OpenBSD/mips64 mips64-*-openbsd*
4191 Morpho Technologies ms1 ms1-elf
4193 * New command line options
4195 --batch-silent As for --batch, but totally silent.
4196 --return-child-result The debugger will exist with the same value
4197 the child (debugged) program exited with.
4198 --eval-command COMMAND, -ex COMMAND
4199 Execute a single GDB CLI command. This may be
4200 specified multiple times and in conjunction
4201 with the --command (-x) option.
4203 * Deprecated commands removed
4205 The following commands, that were deprecated in 2000, have been
4209 set|show arm disassembly-flavor set|show arm disassembler
4210 othernames set arm disassembler
4211 set|show remotedebug set|show debug remote
4212 set|show archdebug set|show debug arch
4213 set|show eventdebug set|show debug event
4216 * New BSD user-level threads support
4218 It is now possible to debug programs using the user-level threads
4219 library on OpenBSD and FreeBSD. Currently supported (target)
4222 FreeBSD/amd64 x86_64-*-freebsd*
4223 FreeBSD/i386 i386-*-freebsd*
4224 OpenBSD/i386 i386-*-openbsd*
4226 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4227 are not yet supported.
4229 * New support for Matsushita MN10300 w/sim added
4230 (Work in progress). mn10300-elf.
4232 * REMOVED configurations and files
4234 VxWorks and the XDR protocol *-*-vxworks
4235 Motorola MCORE mcore-*-*
4236 National Semiconductor NS32000 ns32k-*-*
4238 * New "set print array-indexes" command
4240 After turning this setting "on", GDB prints the index of each element
4241 when displaying arrays. The default is "off" to preserve the previous
4244 * VAX floating point support
4246 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4248 * User-defined command support
4250 In addition to using $arg0..$arg9 for argument passing, it is now possible
4251 to use $argc to determine now many arguments have been passed. See the
4252 section on user-defined commands in the user manual for more information.
4254 *** Changes in GDB 6.3:
4256 * New command line option
4258 GDB now accepts -l followed by a number to set the timeout for remote
4261 * GDB works with GCC -feliminate-dwarf2-dups
4263 GDB now supports a more compact representation of DWARF-2 debug
4264 information using DW_FORM_ref_addr references. These are produced
4265 by GCC with the option -feliminate-dwarf2-dups and also by some
4266 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4267 to use -feliminate-dwarf2-dups.
4269 * Internationalization
4271 When supported by the host system, GDB will be built with
4272 internationalization (libintl). The task of marking up the sources is
4273 continued, we're looking forward to our first translation.
4277 Initial support for debugging programs compiled with the GNAT
4278 implementation of the Ada programming language has been integrated
4279 into GDB. In this release, support is limited to expression evaluation.
4281 * New native configurations
4283 GNU/Linux/m32r m32r-*-linux-gnu
4287 GDB's remote protocol now includes support for the 'p' packet. This
4288 packet is used to fetch individual registers from a remote inferior.
4290 * END-OF-LIFE registers[] compatibility module
4292 GDB's internal register infrastructure has been completely rewritten.
4293 The new infrastructure making possible the implementation of key new
4294 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4297 GDB 6.3 will be the last release to include the the registers[]
4298 compatibility module that allowed out-of-date configurations to
4299 continue to work. This change directly impacts the following
4309 powerpc bdm protocol
4311 Unless there is activity to revive these configurations, they will be
4312 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4314 * OBSOLETE configurations and files
4316 Configurations that have been declared obsolete in this release have
4317 been commented out. Unless there is activity to revive these
4318 configurations, the next release of GDB will have their sources
4319 permanently REMOVED.
4328 *** Changes in GDB 6.2.1:
4330 * MIPS `break main; run' gave an heuristic-fence-post warning
4332 When attempting to run even a simple program, a warning about
4333 heuristic-fence-post being hit would be reported. This problem has
4336 * MIPS IRIX 'long double' crashed GDB
4338 When examining a long double variable, GDB would get a segmentation
4339 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4340 IRIX long double values).
4344 A bug in the VAX stack code was causing problems with the "next"
4345 command. This problem has been fixed.
4347 *** Changes in GDB 6.2:
4349 * Fix for ``many threads''
4351 On GNU/Linux systems that use the NPTL threads library, a program
4352 rapidly creating and deleting threads would confuse GDB leading to the
4355 ptrace: No such process.
4356 thread_db_get_info: cannot get thread info: generic error
4358 This problem has been fixed.
4360 * "-async" and "-noasync" options removed.
4362 Support for the broken "-noasync" option has been removed (it caused
4365 * New ``start'' command.
4367 This command runs the program until the begining of the main procedure.
4369 * New BSD Kernel Data Access Library (libkvm) interface
4371 Using ``target kvm'' it is now possible to debug kernel core dumps and
4372 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4373 platforms. Currently supported (native-only) configurations are:
4375 FreeBSD/amd64 x86_64-*-freebsd*
4376 FreeBSD/i386 i?86-*-freebsd*
4377 NetBSD/i386 i?86-*-netbsd*
4378 NetBSD/m68k m68*-*-netbsd*
4379 NetBSD/sparc sparc-*-netbsd*
4380 OpenBSD/amd64 x86_64-*-openbsd*
4381 OpenBSD/i386 i?86-*-openbsd*
4382 OpenBSD/m68k m68*-openbsd*
4383 OpenBSD/sparc sparc-*-openbsd*
4385 * Signal trampoline code overhauled
4387 Many generic problems with GDB's signal handling code have been fixed.
4388 These include: backtraces through non-contiguous stacks; recognition
4389 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4390 call; backtrace through a signal trampoline; step into and out of
4391 signal handlers; and single-stepping in the signal trampoline.
4393 Please note that kernel bugs are a limiting factor here. These
4394 features have been shown to work on an s390 GNU/Linux system that
4395 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4397 * Cygwin support for DWARF 2 added.
4399 * New native configurations
4401 GNU/Linux/hppa hppa*-*-linux*
4402 OpenBSD/hppa hppa*-*-openbsd*
4403 OpenBSD/m68k m68*-*-openbsd*
4404 OpenBSD/m88k m88*-*-openbsd*
4405 OpenBSD/powerpc powerpc-*-openbsd*
4406 NetBSD/vax vax-*-netbsd*
4407 OpenBSD/vax vax-*-openbsd*
4409 * END-OF-LIFE frame compatibility module
4411 GDB's internal frame infrastructure has been completely rewritten.
4412 The new infrastructure making it possible to support key new features
4413 including DWARF 2 Call Frame Information. To aid in the task of
4414 migrating old configurations to this new infrastructure, a
4415 compatibility module, that allowed old configurations to continue to
4416 work, was also included.
4418 GDB 6.2 will be the last release to include this frame compatibility
4419 module. This change directly impacts the following configurations:
4429 Unless there is activity to revive these configurations, they will be
4430 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4432 * REMOVED configurations and files
4434 Sun 3, running SunOS 3 m68*-*-sunos3*
4435 Sun 3, running SunOS 4 m68*-*-sunos4*
4436 Sun 2, running SunOS 3 m68000-*-sunos3*
4437 Sun 2, running SunOS 4 m68000-*-sunos4*
4438 Motorola 680x0 running LynxOS m68*-*-lynxos*
4439 AT&T 3b1/Unix pc m68*-att-*
4440 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4441 decstation mips-dec-* mips-little-*
4442 riscos mips-*-riscos* mips-*-sysv*
4443 sonymips mips-sony-*
4444 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4446 *** Changes in GDB 6.1.1:
4448 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4450 The TUI (Text-mode User Interface) is now built as part of a default
4451 GDB configuration. It is enabled by either selecting the TUI with the
4452 command line option "-i=tui" or by running the separate "gdbtui"
4453 program. For more information on the TUI, see the manual "Debugging
4456 * Pending breakpoint support (also included in GDB 6.1)
4458 Support has been added to allow you to specify breakpoints in shared
4459 libraries that have not yet been loaded. If a breakpoint location
4460 cannot be found, and the "breakpoint pending" option is set to auto,
4461 GDB queries you if you wish to make the breakpoint pending on a future
4462 shared-library load. If and when GDB resolves the breakpoint symbol,
4463 the pending breakpoint is removed as one or more regular breakpoints
4466 Pending breakpoints are very useful for GCJ Java debugging.
4468 * Fixed ISO-C build problems
4470 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4471 non ISO-C code that stopped them being built using a more strict ISO-C
4472 compiler (e.g., IBM's C compiler).
4474 * Fixed build problem on IRIX 5
4476 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4477 wasn't able to compile compile on an IRIX 5 system.
4479 * Added execute permission to gdb/gdbserver/configure
4481 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4482 permission. This bug would cause configure to fail on a number of
4483 systems (Solaris, IRIX). Ref: server/519.
4485 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4487 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4488 has been updated to use constant array sizes.
4490 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4492 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4493 its generated DWARF Call Frame Info. This encoding was causing GDB to
4494 panic, that panic has been fixed. Ref: gdb/1628.
4496 * Fixed a problem when examining parameters in shared library code.
4498 When examining parameters in optimized shared library code generated
4499 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4500 not available''. GDB now correctly displays the variable's value.
4502 *** Changes in GDB 6.1:
4504 * Removed --with-mmalloc
4506 Support for the mmalloc memory manager has been removed, as it
4507 conflicted with the internal gdb byte cache.
4509 * Changes in AMD64 configurations
4511 The AMD64 target now includes the %cs and %ss registers. As a result
4512 the AMD64 remote protocol has changed; this affects the floating-point
4513 and SSE registers. If you rely on those registers for your debugging,
4514 you should upgrade gdbserver on the remote side.
4516 * Revised SPARC target
4518 The SPARC target has been completely revised, incorporating the
4519 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4520 support for LynxOS and SunOS 4 has been dropped. Calling functions
4521 from within GDB on operating systems with a non-executable stack
4522 (Solaris, OpenBSD) now works.
4526 GDB has a new C++ demangler which does a better job on the mangled
4527 names generated by current versions of g++. It also runs faster, so
4528 with this and other changes gdb should now start faster on large C++
4531 * DWARF 2 Location Expressions
4533 GDB support for location expressions has been extended to support function
4534 arguments and frame bases. Older versions of GDB could crash when they
4537 * C++ nested types and namespaces
4539 GDB's support for nested types and namespaces in C++ has been
4540 improved, especially if you use the DWARF 2 debugging format. (This
4541 is the default for recent versions of GCC on most platforms.)
4542 Specifically, if you have a class "Inner" defined within a class or
4543 namespace "Outer", then GDB realizes that the class's name is
4544 "Outer::Inner", not simply "Inner". This should greatly reduce the
4545 frequency of complaints about not finding RTTI symbols. In addition,
4546 if you are stopped at inside of a function defined within a namespace,
4547 GDB modifies its name lookup accordingly.
4549 * New native configurations
4551 NetBSD/amd64 x86_64-*-netbsd*
4552 OpenBSD/amd64 x86_64-*-openbsd*
4553 OpenBSD/alpha alpha*-*-openbsd*
4554 OpenBSD/sparc sparc-*-openbsd*
4555 OpenBSD/sparc64 sparc64-*-openbsd*
4557 * New debugging protocols
4559 M32R with SDI protocol m32r-*-elf*
4561 * "set prompt-escape-char" command deleted.
4563 The command "set prompt-escape-char" has been deleted. This command,
4564 and its very obscure effet on GDB's prompt, was never documented,
4565 tested, nor mentioned in the NEWS file.
4567 * OBSOLETE configurations and files
4569 Configurations that have been declared obsolete in this release have
4570 been commented out. Unless there is activity to revive these
4571 configurations, the next release of GDB will have their sources
4572 permanently REMOVED.
4574 Sun 3, running SunOS 3 m68*-*-sunos3*
4575 Sun 3, running SunOS 4 m68*-*-sunos4*
4576 Sun 2, running SunOS 3 m68000-*-sunos3*
4577 Sun 2, running SunOS 4 m68000-*-sunos4*
4578 Motorola 680x0 running LynxOS m68*-*-lynxos*
4579 AT&T 3b1/Unix pc m68*-att-*
4580 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4581 decstation mips-dec-* mips-little-*
4582 riscos mips-*-riscos* mips-*-sysv*
4583 sonymips mips-sony-*
4584 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4586 * REMOVED configurations and files
4588 SGI Irix-4.x mips-sgi-irix4 or iris4
4589 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4590 Z8000 simulator z8k-zilog-none or z8ksim
4591 Matsushita MN10200 w/simulator mn10200-*-*
4592 H8/500 simulator h8500-hitachi-hms or h8500hms
4593 HP/PA running BSD hppa*-*-bsd*
4594 HP/PA running OSF/1 hppa*-*-osf*
4595 HP/PA Pro target hppa*-*-pro*
4596 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4597 386BSD i[3456]86-*-bsd*
4598 Sequent family i[3456]86-sequent-sysv4*
4599 i[3456]86-sequent-sysv*
4600 i[3456]86-sequent-bsd*
4601 SPARC running LynxOS sparc-*-lynxos*
4602 SPARC running SunOS 4 sparc-*-sunos4*
4603 Tsqware Sparclet sparclet-*-*
4604 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4606 *** Changes in GDB 6.0:
4610 Support for debugging the Objective-C programming language has been
4611 integrated into GDB.
4613 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4615 DWARF 2's Call Frame Information makes available compiler generated
4616 information that more exactly describes the program's run-time stack.
4617 By using this information, GDB is able to provide more robust stack
4620 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4621 have been updated to use a new backtrace mechanism which includes
4622 DWARF 2 CFI support.
4626 GDB's remote protocol has been extended to include support for hosted
4627 file I/O (where the remote target uses GDB's file system). See GDB's
4628 remote protocol documentation for details.
4630 * All targets using the new architecture framework.
4632 All of GDB's targets have been updated to use the new internal
4633 architecture framework. The way is now open for future GDB releases
4634 to include cross-architecture native debugging support (i386 on amd64,
4637 * GNU/Linux's Thread Local Storage (TLS)
4639 GDB now includes support for for the GNU/Linux implementation of
4640 per-thread variables.
4642 * GNU/Linux's Native POSIX Thread Library (NPTL)
4644 GDB's thread code has been updated to work with either the new
4645 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4647 * Separate debug info.
4649 GDB, in conjunction with BINUTILS, now supports a mechanism for
4650 automatically loading debug information from a separate file. Instead
4651 of shipping full debug and non-debug versions of system libraries,
4652 system integrators can now instead ship just the stripped libraries
4653 and optional debug files.
4655 * DWARF 2 Location Expressions
4657 DWARF 2 Location Expressions allow the compiler to more completely
4658 describe the location of variables (even in optimized code) to the
4661 GDB now includes preliminary support for location expressions (support
4662 for DW_OP_piece is still missing).
4666 A number of long standing bugs that caused GDB to die while starting a
4667 Java application have been fixed. GDB's Java support is now
4668 considered "useable".
4670 * GNU/Linux support for fork, vfork, and exec.
4672 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4673 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4676 * GDB supports logging output to a file
4678 There are two new commands, "set logging" and "show logging", which can be
4679 used to capture GDB's output to a file.
4681 * The meaning of "detach" has changed for gdbserver
4683 The "detach" command will now resume the application, as documented. To
4684 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4687 * d10v, m68hc11 `regs' command deprecated
4689 The `info registers' command has been updated so that it displays the
4690 registers using a format identical to the old `regs' command.
4694 A new command, "maint set profile on/off", has been added. This command can
4695 be used to enable or disable profiling while running GDB, to profile a
4696 session or a set of commands. In addition there is a new configure switch,
4697 "--enable-profiling", which will cause GDB to be compiled with profiling
4698 data, for more informative profiling results.
4700 * Default MI syntax changed to "mi2".
4702 The default MI (machine interface) syntax, enabled by the command line
4703 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4704 "mi1", can be enabled by specifying the option "-i=mi1".
4706 Support for the original "mi0" syntax (included in GDB 5.0) has been
4709 Fix for gdb/192: removed extraneous space when displaying frame level.
4710 Fix for gdb/672: update changelist is now output in mi list format.
4711 Fix for gdb/702: a -var-assign that updates the value now shows up
4712 in a subsequent -var-update.
4714 * New native configurations.
4716 FreeBSD/amd64 x86_64-*-freebsd*
4718 * Multi-arched targets.
4720 HP/PA HPUX11 hppa*-*-hpux*
4721 Renesas M32R/D w/simulator m32r-*-elf*
4723 * OBSOLETE configurations and files
4725 Configurations that have been declared obsolete in this release have
4726 been commented out. Unless there is activity to revive these
4727 configurations, the next release of GDB will have their sources
4728 permanently REMOVED.
4730 Z8000 simulator z8k-zilog-none or z8ksim
4731 Matsushita MN10200 w/simulator mn10200-*-*
4732 H8/500 simulator h8500-hitachi-hms or h8500hms
4733 HP/PA running BSD hppa*-*-bsd*
4734 HP/PA running OSF/1 hppa*-*-osf*
4735 HP/PA Pro target hppa*-*-pro*
4736 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4737 Sequent family i[3456]86-sequent-sysv4*
4738 i[3456]86-sequent-sysv*
4739 i[3456]86-sequent-bsd*
4740 Tsqware Sparclet sparclet-*-*
4741 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4743 * REMOVED configurations and files
4746 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4747 IBM AIX PS/2 i[3456]86-*-aix
4748 i386 running Mach 3.0 i[3456]86-*-mach3*
4749 i386 running Mach i[3456]86-*-mach*
4750 i386 running OSF/1 i[3456]86-*osf1mk*
4751 HP/Apollo 68k Family m68*-apollo*-sysv*,
4753 m68*-hp-bsd*, m68*-hp-hpux*
4754 Argonaut Risc Chip (ARC) arc-*-*
4755 Mitsubishi D30V d30v-*-*
4756 Fujitsu FR30 fr30-*-elf*
4757 OS/9000 i[34]86-*-os9k
4758 I960 with MON960 i960-*-coff
4760 * MIPS $fp behavior changed
4762 The convenience variable $fp, for the MIPS, now consistently returns
4763 the address of the current frame's base. Previously, depending on the
4764 context, $fp could refer to either $sp or the current frame's base
4765 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4766 The GNU Source-Level Debugger''.
4768 *** Changes in GDB 5.3:
4770 * GNU/Linux shared library multi-threaded performance improved.
4772 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4773 `/proc', in preference to `ptrace' for memory reads. This may result
4774 in an improvement in the start-up time of multi-threaded, shared
4775 library applications when run under GDB. One GDB user writes: ``loads
4776 shared libs like mad''.
4778 * ``gdbserver'' now supports multi-threaded applications on some targets
4780 Support for debugging multi-threaded applications which use
4781 the GNU/Linux LinuxThreads package has been added for
4782 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4783 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4785 * GDB now supports C/C++ preprocessor macros.
4787 GDB now expands preprocessor macro invocations in C/C++ expressions,
4788 and provides various commands for showing macro definitions and how
4791 The new command `macro expand EXPRESSION' expands any macro
4792 invocations in expression, and shows the result.
4794 The new command `show macro MACRO-NAME' shows the definition of the
4795 macro named MACRO-NAME, and where it was defined.
4797 Most compilers don't include information about macros in the debugging
4798 information by default. In GCC 3.1, for example, you need to compile
4799 your program with the options `-gdwarf-2 -g3'. If the macro
4800 information is present in the executable, GDB will read it.
4802 * Multi-arched targets.
4804 DEC Alpha (partial) alpha*-*-*
4805 DEC VAX (partial) vax-*-*
4807 National Semiconductor NS32000 (partial) ns32k-*-*
4808 Motorola 68000 (partial) m68k-*-*
4809 Motorola MCORE mcore-*-*
4813 Fujitsu FRV architecture added by Red Hat frv*-*-*
4816 * New native configurations
4818 Alpha NetBSD alpha*-*-netbsd*
4819 SH NetBSD sh*-*-netbsdelf*
4820 MIPS NetBSD mips*-*-netbsd*
4821 UltraSPARC NetBSD sparc64-*-netbsd*
4823 * OBSOLETE configurations and files
4825 Configurations that have been declared obsolete in this release have
4826 been commented out. Unless there is activity to revive these
4827 configurations, the next release of GDB will have their sources
4828 permanently REMOVED.
4830 Mitsubishi D30V d30v-*-*
4831 OS/9000 i[34]86-*-os9k
4832 IBM AIX PS/2 i[3456]86-*-aix
4833 Fujitsu FR30 fr30-*-elf*
4834 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4835 Argonaut Risc Chip (ARC) arc-*-*
4836 i386 running Mach 3.0 i[3456]86-*-mach3*
4837 i386 running Mach i[3456]86-*-mach*
4838 i386 running OSF/1 i[3456]86-*osf1mk*
4839 HP/Apollo 68k Family m68*-apollo*-sysv*,
4841 m68*-hp-bsd*, m68*-hp-hpux*
4842 I960 with MON960 i960-*-coff
4844 * OBSOLETE languages
4846 CHILL, a Pascal like language used by telecommunications companies.
4848 * REMOVED configurations and files
4850 AMD 29k family via UDI a29k-amd-udi, udi29k
4851 A29K VxWorks a29k-*-vxworks
4852 AMD 29000 embedded, using EBMON a29k-none-none
4853 AMD 29000 embedded with COFF a29k-none-coff
4854 AMD 29000 embedded with a.out a29k-none-aout
4856 testsuite/gdb.hp/gdb.threads-hp/ directory
4858 * New command "set max-user-call-depth <nnn>"
4860 This command allows the user to limit the call depth of user-defined
4861 commands. The default is 1024.
4863 * Changes in FreeBSD/i386 native debugging.
4865 Support for the "generate-core-file" has been added.
4867 * New commands "dump", "append", and "restore".
4869 These commands allow data to be copied from target memory
4870 to a bfd-format or binary file (dump and append), and back
4871 from a file into memory (restore).
4873 * Improved "next/step" support on multi-processor Alpha Tru64.
4875 The previous single-step mechanism could cause unpredictable problems,
4876 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4877 of a software single-step mechanism prevents this.
4879 *** Changes in GDB 5.2.1:
4887 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4888 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4889 Fix, by Joel Brobecker imported from mainline.
4891 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4892 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4893 Fix, by Fred Fish, imported from mainline.
4895 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4896 Surprisingly enough, it works now.
4897 By Michal Ludvig, imported from mainline.
4899 i386 hardware watchpoint support:
4900 avoid misses on second run for some targets.
4901 By Pierre Muller, imported from mainline.
4903 *** Changes in GDB 5.2:
4905 * New command "set trust-readonly-sections on[off]".
4907 This command is a hint that tells gdb that read-only sections
4908 really are read-only (ie. that their contents will not change).
4909 In this mode, gdb will go to the object file rather than the
4910 target to read memory from read-only sections (such as ".text").
4911 This can be a significant performance improvement on some
4912 (notably embedded) targets.
4914 * New command "generate-core-file" (or "gcore").
4916 This new gdb command allows the user to drop a core file of the child
4917 process state at any time. So far it's been implemented only for
4918 GNU/Linux and Solaris, but should be relatively easily ported to other
4919 hosts. Argument is core file name (defaults to core.<pid>).
4921 * New command line option
4923 GDB now accepts --pid or -p followed by a process id.
4925 * Change in command line behavior -- corefiles vs. process ids.
4927 There is a subtle behavior in the way in which GDB handles
4928 command line arguments. The first non-flag argument is always
4929 a program to debug, but the second non-flag argument may either
4930 be a corefile or a process id. Previously, GDB would attempt to
4931 open the second argument as a corefile, and if that failed, would
4932 issue a superfluous error message and then attempt to attach it as
4933 a process. Now, if the second argument begins with a non-digit,
4934 it will be treated as a corefile. If it begins with a digit,
4935 GDB will attempt to attach it as a process, and if no such process
4936 is found, will then attempt to open it as a corefile.
4938 * Changes in ARM configurations.
4940 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4941 configuration is fully multi-arch.
4943 * New native configurations
4945 ARM NetBSD arm*-*-netbsd*
4946 x86 OpenBSD i[3456]86-*-openbsd*
4947 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4948 Sparc64 running FreeBSD sparc64-*-freebsd*
4952 Sanyo XStormy16 xstormy16-elf
4954 * OBSOLETE configurations and files
4956 Configurations that have been declared obsolete in this release have
4957 been commented out. Unless there is activity to revive these
4958 configurations, the next release of GDB will have their sources
4959 permanently REMOVED.
4961 AMD 29k family via UDI a29k-amd-udi, udi29k
4962 A29K VxWorks a29k-*-vxworks
4963 AMD 29000 embedded, using EBMON a29k-none-none
4964 AMD 29000 embedded with COFF a29k-none-coff
4965 AMD 29000 embedded with a.out a29k-none-aout
4967 testsuite/gdb.hp/gdb.threads-hp/ directory
4969 * REMOVED configurations and files
4971 TI TMS320C80 tic80-*-*
4973 PowerPC Solaris powerpcle-*-solaris*
4974 PowerPC Windows NT powerpcle-*-cygwin32
4975 PowerPC Netware powerpc-*-netware*
4976 Harris/CXUX m88k m88*-harris-cxux*
4977 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
4978 ns32k-utek-sysv* ns32k-utek-*
4979 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
4980 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
4981 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
4982 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
4983 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
4985 * Changes to command line processing
4987 The new `--args' feature can be used to specify command-line arguments
4988 for the inferior from gdb's command line.
4990 * Changes to key bindings
4992 There is a new `operate-and-get-next' function bound to `C-o'.
4994 *** Changes in GDB 5.1.1
4996 Fix compile problem on DJGPP.
4998 Fix a problem with floating-point registers on the i386 being
5001 Fix to stop GDB crashing on .debug_str debug info.
5003 Numerous documentation fixes.
5005 Numerous testsuite fixes.
5007 *** Changes in GDB 5.1:
5009 * New native configurations
5011 Alpha FreeBSD alpha*-*-freebsd*
5012 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5013 MIPS GNU/Linux mips*-*-linux*
5014 MIPS SGI Irix 6.x mips*-sgi-irix6*
5015 ia64 AIX ia64-*-aix*
5016 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5020 Motorola 68HC11 and 68HC12 m68hc11-elf
5022 UltraSparc running GNU/Linux sparc64-*-linux*
5024 * OBSOLETE configurations and files
5026 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5027 Harris/CXUX m88k m88*-harris-cxux*
5028 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5029 ns32k-utek-sysv* ns32k-utek-*
5030 TI TMS320C80 tic80-*-*
5032 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5033 PowerPC Solaris powerpcle-*-solaris*
5034 PowerPC Windows NT powerpcle-*-cygwin32
5035 PowerPC Netware powerpc-*-netware*
5036 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5037 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5038 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5039 Apple Macintosh (MPW) host N/A
5041 stuff.c (Program to stuff files into a specially prepared space in kdb)
5042 kdb-start.c (Main loop for the standalone kernel debugger)
5044 Configurations that have been declared obsolete in this release have
5045 been commented out. Unless there is activity to revive these
5046 configurations, the next release of GDB will have their sources
5047 permanently REMOVED.
5049 * REMOVED configurations and files
5051 Altos 3068 m68*-altos-*
5052 Convex c1-*-*, c2-*-*
5054 ARM RISCix arm-*-* (as host)
5058 * GDB has been converted to ISO C.
5060 GDB's source code has been converted to ISO C. In particular, the
5061 sources are fully protoized, and rely on standard headers being
5066 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5068 * The MI enabled by default.
5070 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5071 revised and enabled by default. Packages which use GDB as a debugging
5072 engine behind a UI or another front end are encouraged to switch to
5073 using the GDB/MI interface, instead of the old annotations interface
5074 which is now deprecated.
5076 * Support for debugging Pascal programs.
5078 GDB now includes support for debugging Pascal programs. The following
5079 main features are supported:
5081 - Pascal-specific data types such as sets;
5083 - automatic recognition of Pascal sources based on file-name
5086 - Pascal-style display of data types, variables, and functions;
5088 - a Pascal expression parser.
5090 However, some important features are not yet supported.
5092 - Pascal string operations are not supported at all;
5094 - there are some problems with boolean types;
5096 - Pascal type hexadecimal constants are not supported
5097 because they conflict with the internal variables format;
5099 - support for Pascal objects and classes is not full yet;
5101 - unlike Pascal, GDB is case-sensitive for symbol names.
5103 * Changes in completion.
5105 Commands such as `shell', `run' and `set args', which pass arguments
5106 to inferior programs, now complete on file names, similar to what
5107 users expect at the shell prompt.
5109 Commands which accept locations, such as `disassemble', `print',
5110 `breakpoint', `until', etc. now complete on filenames as well as
5111 program symbols. Thus, if you type "break foob TAB", and the source
5112 files linked into the programs include `foobar.c', that file name will
5113 be one of the candidates for completion. However, file names are not
5114 considered for completion after you typed a colon that delimits a file
5115 name from a name of a function in that file, as in "break foo.c:bar".
5117 `set demangle-style' completes on available demangling styles.
5119 * New platform-independent commands:
5121 It is now possible to define a post-hook for a command as well as a
5122 hook that runs before the command. For more details, see the
5123 documentation of `hookpost' in the GDB manual.
5125 * Changes in GNU/Linux native debugging.
5127 Support for debugging multi-threaded programs has been completely
5128 revised for all platforms except m68k and sparc. You can now debug as
5129 many threads as your system allows you to have.
5131 Attach/detach is supported for multi-threaded programs.
5133 Support for SSE registers was added for x86. This doesn't work for
5134 multi-threaded programs though.
5136 * Changes in MIPS configurations.
5138 Multi-arch support is enabled for all MIPS configurations.
5140 GDB can now be built as native debugger on SGI Irix 6.x systems for
5141 debugging n32 executables. (Debugging 64-bit executables is not yet
5144 * Unified support for hardware watchpoints in all x86 configurations.
5146 Most (if not all) native x86 configurations support hardware-assisted
5147 breakpoints and watchpoints in a unified manner. This support
5148 implements debug register sharing between watchpoints, which allows to
5149 put a virtually infinite number of watchpoints on the same address,
5150 and also supports watching regions up to 16 bytes with several debug
5153 The new maintenance command `maintenance show-debug-regs' toggles
5154 debugging print-outs in functions that insert, remove, and test
5155 watchpoints and hardware breakpoints.
5157 * Changes in the DJGPP native configuration.
5159 New command ``info dos sysinfo'' displays assorted information about
5160 the CPU, OS, memory, and DPMI server.
5162 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5163 display information about segment descriptors stored in GDT, LDT, and
5166 New commands ``info dos pde'' and ``info dos pte'' display entries
5167 from Page Directory and Page Tables (for now works with CWSDPMI only).
5168 New command ``info dos address-pte'' displays the Page Table entry for
5169 a given linear address.
5171 GDB can now pass command lines longer than 126 characters to the
5172 program being debugged (requires an update to the libdbg.a library
5173 which is part of the DJGPP development kit).
5175 DWARF2 debug info is now supported.
5177 It is now possible to `step' and `next' through calls to `longjmp'.
5179 * Changes in documentation.
5181 All GDB documentation was converted to GFDL, the GNU Free
5182 Documentation License.
5184 Tracepoints-related commands are now fully documented in the GDB
5187 TUI, the Text-mode User Interface, is now documented in the manual.
5189 Tracepoints-related commands are now fully documented in the GDB
5192 The "GDB Internals" manual now has an index. It also includes
5193 documentation of `ui_out' functions, GDB coding standards, x86
5194 hardware watchpoints, and memory region attributes.
5196 * GDB's version number moved to ``version.in''
5198 The Makefile variable VERSION has been replaced by the file
5199 ``version.in''. People creating GDB distributions should update the
5200 contents of this file.
5204 GUD support is now a standard part of the EMACS distribution.
5206 *** Changes in GDB 5.0:
5208 * Improved support for debugging FP programs on x86 targets
5210 Unified and much-improved support for debugging floating-point
5211 programs on all x86 targets. In particular, ``info float'' now
5212 displays the FP registers in the same format on all x86 targets, with
5213 greater level of detail.
5215 * Improvements and bugfixes in hardware-assisted watchpoints
5217 It is now possible to watch array elements, struct members, and
5218 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5219 on x86 targets no longer erroneously trigger when the address is
5222 * Improvements in the native DJGPP version of GDB
5224 The distribution now includes all the scripts and auxiliary files
5225 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5226 machines ``out of the box''.
5228 The DJGPP version can now debug programs that use signals. It is
5229 possible to catch signals that happened in the debuggee, deliver
5230 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5231 would kill the program being debugged.) Programs that hook hardware
5232 interrupts (keyboard, timer, etc.) can also be debugged.
5234 It is now possible to debug DJGPP programs that redirect their
5235 standard handles or switch them to raw (as opposed to cooked) mode, or
5236 even close them. The command ``run < foo > bar'' works as expected,
5237 and ``info terminal'' reports useful information about the debuggee's
5238 terminal, including raw/cooked mode, redirection, etc.
5240 The DJGPP version now uses termios functions for console I/O, which
5241 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5244 DOS-style file names with drive letters are now fully supported by
5247 It is now possible to debug DJGPP programs that switch their working
5248 directory. It is also possible to rerun the debuggee any number of
5249 times without restarting GDB; thus, you can use the same setup,
5250 breakpoints, etc. for many debugging sessions.
5252 * New native configurations
5254 ARM GNU/Linux arm*-*-linux*
5255 PowerPC GNU/Linux powerpc-*-linux*
5259 Motorola MCore mcore-*-*
5260 x86 VxWorks i[3456]86-*-vxworks*
5261 PowerPC VxWorks powerpc-*-vxworks*
5262 TI TMS320C80 tic80-*-*
5264 * OBSOLETE configurations
5266 Altos 3068 m68*-altos-*
5267 Convex c1-*-*, c2-*-*
5269 ARM RISCix arm-*-* (as host)
5272 Configurations that have been declared obsolete will be commented out,
5273 but the code will be left in place. If there is no activity to revive
5274 these configurations before the next release of GDB, the sources will
5275 be permanently REMOVED.
5277 * Gould support removed
5279 Support for the Gould PowerNode and NP1 has been removed.
5281 * New features for SVR4
5283 On SVR4 native platforms (such as Solaris), if you attach to a process
5284 without first loading a symbol file, GDB will now attempt to locate and
5285 load symbols from the running process's executable file.
5287 * Many C++ enhancements
5289 C++ support has been greatly improved. Overload resolution now works properly
5290 in almost all cases. RTTI support is on the way.
5292 * Remote targets can connect to a sub-program
5294 A popen(3) style serial-device has been added. This device starts a
5295 sub-process (such as a stand-alone simulator) and then communicates
5296 with that. The sub-program to run is specified using the syntax
5297 ``|<program> <args>'' vis:
5299 (gdb) set remotedebug 1
5300 (gdb) target extended-remote |mn10300-elf-sim program-args
5302 * MIPS 64 remote protocol
5304 A long standing bug in the mips64 remote protocol where by GDB
5305 expected certain 32 bit registers (ex SR) to be transfered as 32
5306 instead of 64 bits has been fixed.
5308 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5309 added to provide backward compatibility with older versions of GDB.
5311 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5313 The command ``set remotebinarydownload'' command has been replaced by
5314 ``set remote X-packet''. Other commands in ``set remote'' family
5315 include ``set remote P-packet''.
5317 * Breakpoint commands accept ranges.
5319 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5320 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5321 ``tracepoint passcount'' also accepts a range of tracepoints.
5323 * ``apropos'' command added.
5325 The ``apropos'' command searches through command names and
5326 documentation strings, printing out matches, making it much easier to
5327 try to find a command that does what you are looking for.
5331 A new machine oriented interface (MI) has been added to GDB. This
5332 interface is designed for debug environments running GDB as a separate
5333 process. This is part of the long term libGDB project. See the
5334 "GDB/MI" chapter of the GDB manual for further information. It can be
5335 enabled by configuring with:
5337 .../configure --enable-gdbmi
5339 *** Changes in GDB-4.18:
5341 * New native configurations
5343 HP-UX 10.20 hppa*-*-hpux10.20
5344 HP-UX 11.x hppa*-*-hpux11.0*
5345 M68K GNU/Linux m68*-*-linux*
5349 Fujitsu FR30 fr30-*-elf*
5350 Intel StrongARM strongarm-*-*
5351 Mitsubishi D30V d30v-*-*
5353 * OBSOLETE configurations
5355 Gould PowerNode, NP1 np1-*-*, pn-*-*
5357 Configurations that have been declared obsolete will be commented out,
5358 but the code will be left in place. If there is no activity to revive
5359 these configurations before the next release of GDB, the sources will
5360 be permanently REMOVED.
5364 As a compatibility experiment, GDB's source files buildsym.h and
5365 buildsym.c have been converted to pure standard C, no longer
5366 containing any K&R compatibility code. We believe that all systems in
5367 use today either come with a standard C compiler, or have a GCC port
5368 available. If this is not true, please report the affected
5369 configuration to bug-gdb@gnu.org immediately. See the README file for
5370 information about getting a standard C compiler if you don't have one
5375 GDB now uses readline 2.2.
5377 * set extension-language
5379 You can now control the mapping between filename extensions and source
5380 languages by using the `set extension-language' command. For instance,
5381 you can ask GDB to treat .c files as C++ by saying
5382 set extension-language .c c++
5383 The command `info extensions' lists all of the recognized extensions
5384 and their associated languages.
5386 * Setting processor type for PowerPC and RS/6000
5388 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5389 you can use the `set processor' command to specify what variant of the
5390 PowerPC family you are debugging. The command
5394 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5395 following PowerPC and RS6000 variants:
5397 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5398 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5400 403GC IBM PowerPC 403GC
5401 505 Motorola PowerPC 505
5402 860 Motorola PowerPC 860 or 850
5403 601 Motorola PowerPC 601
5404 602 Motorola PowerPC 602
5405 603 Motorola/IBM PowerPC 603 or 603e
5406 604 Motorola PowerPC 604 or 604e
5407 750 Motorola/IBM PowerPC 750 or 750
5409 At the moment, this command just tells GDB what to name the
5410 special-purpose processor registers. Since almost all the affected
5411 registers are inaccessible to user-level programs, this command is
5412 only useful for remote debugging in its present form.
5416 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5417 more extensive support for HP-UX. Added features include shared
5418 library support, kernel threads and hardware watchpoints for 11.00,
5419 support for HP's ANSI C and C++ compilers, and a compatibility mode
5420 for xdb and dbx commands.
5424 HP's donation includes the new concept of catchpoints, which is a
5425 generalization of the old catch command. On HP-UX, it is now possible
5426 to catch exec, fork, and vfork, as well as library loading.
5428 This means that the existing catch command has changed; its first
5429 argument now specifies the type of catch to be set up. See the
5430 output of "help catch" for a list of catchpoint types.
5432 * Debugging across forks
5434 On HP-UX, you can choose which process to debug when a fork() happens
5439 HP has donated a curses-based terminal user interface (TUI). To get
5440 it, build with --enable-tui. Although this can be enabled for any
5441 configuration, at present it only works for native HP debugging.
5443 * GDB remote protocol additions
5445 A new protocol packet 'X' that writes binary data is now available.
5446 Default behavior is to try 'X', then drop back to 'M' if the stub
5447 fails to respond. The settable variable `remotebinarydownload'
5448 allows explicit control over the use of 'X'.
5450 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5451 full 64-bit address. The command
5453 set remoteaddresssize 32
5455 can be used to revert to the old behaviour. For existing remote stubs
5456 the change should not be noticed, as the additional address information
5459 In order to assist in debugging stubs, you may use the maintenance
5460 command `packet' to send any text string to the stub. For instance,
5462 maint packet heythere
5464 sends the packet "$heythere#<checksum>". Note that it is very easy to
5465 disrupt a debugging session by sending the wrong packet at the wrong
5468 The compare-sections command allows you to compare section data on the
5469 target to what is in the executable file without uploading or
5470 downloading, by comparing CRC checksums.
5472 * Tracing can collect general expressions
5474 You may now collect general expressions at tracepoints. This requires
5475 further additions to the target-side stub; see tracepoint.c and
5476 doc/agentexpr.texi for further details.
5478 * mask-address variable for Mips
5480 For Mips targets, you may control the zeroing of the upper 32 bits of
5481 a 64-bit address by entering `set mask-address on'. This is mainly
5482 of interest to users of embedded R4xxx and R5xxx processors.
5484 * Higher serial baud rates
5486 GDB's serial code now allows you to specify baud rates 57600, 115200,
5487 230400, and 460800 baud. (Note that your host system may not be able
5488 to achieve all of these rates.)
5492 The i960 configuration now includes an initial implementation of a
5493 builtin simulator, contributed by Jim Wilson.
5496 *** Changes in GDB-4.17:
5498 * New native configurations
5500 Alpha GNU/Linux alpha*-*-linux*
5501 Unixware 2.x i[3456]86-unixware2*
5502 Irix 6.x mips*-sgi-irix6*
5503 PowerPC GNU/Linux powerpc-*-linux*
5504 PowerPC Solaris powerpcle-*-solaris*
5505 Sparc GNU/Linux sparc-*-linux*
5506 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5510 Argonaut Risc Chip (ARC) arc-*-*
5511 Hitachi H8/300S h8300*-*-*
5512 Matsushita MN10200 w/simulator mn10200-*-*
5513 Matsushita MN10300 w/simulator mn10300-*-*
5514 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5515 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5516 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5517 Mitsubishi D10V w/simulator d10v-*-*
5518 Mitsubishi M32R/D w/simulator m32r-*-elf*
5519 Tsqware Sparclet sparclet-*-*
5520 NEC V850 w/simulator v850-*-*
5522 * New debugging protocols
5524 ARM with RDI protocol arm*-*-*
5525 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5526 DDB and LSI variants of PMON protocol mips*-*-*
5527 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5528 PowerPC with SDS protocol powerpc{,le}-*-eabi
5529 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5533 All configurations can now understand and use the DWARF 2 debugging
5534 format. The choice is automatic, if the symbol file contains DWARF 2
5539 GDB now includes basic Java language support. This support is
5540 only useful with Java compilers that produce native machine code.
5542 * solib-absolute-prefix and solib-search-path
5544 For SunOS and SVR4 shared libraries, you may now set the prefix for
5545 loading absolute shared library symbol files, and the search path for
5546 locating non-absolute shared library symbol files.
5548 * Live range splitting
5550 GDB can now effectively debug code for which GCC has performed live
5551 range splitting as part of its optimization. See gdb/doc/LRS for
5552 more details on the expected format of the stabs information.
5556 GDB's support for the GNU Hurd, including thread debugging, has been
5557 updated to work with current versions of the Hurd.
5561 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5562 instruction set. ARM GDB automatically detects when Thumb
5563 instructions are in use, and adjusts disassembly and backtracing
5568 GDB's MIPS target configurations now handle the MIP16 16-bit
5573 GDB now includes support for overlays; if an executable has been
5574 linked such that multiple sections are based at the same address, GDB
5575 will decide which section to use for symbolic info. You can choose to
5576 control the decision manually, using overlay commands, or implement
5577 additional target-side support and use "overlay load-target" to bring
5578 in the overlay mapping. Do "help overlay" for more detail.
5582 The command "info symbol <address>" displays information about
5583 the symbol at the specified address.
5587 The standard remote protocol now includes an extension that allows
5588 asynchronous collection and display of trace data. This requires
5589 extensive support in the target-side debugging stub. Tracing mode
5590 includes a new interaction mode in GDB and new commands: see the
5591 file tracepoint.c for more details.
5595 Configurations for embedded MIPS now include a simulator contributed
5596 by Cygnus Solutions. The simulator supports the instruction sets
5597 of most MIPS variants.
5601 Sparc configurations may now include the ERC32 simulator contributed
5602 by the European Space Agency. The simulator is not built into
5603 Sparc targets by default; configure with --enable-sim to include it.
5607 For target configurations that may include multiple variants of a
5608 basic architecture (such as MIPS and SH), you may now set the
5609 architecture explicitly. "set arch" sets, "info arch" lists
5610 the possible architectures.
5612 *** Changes in GDB-4.16:
5614 * New native configurations
5616 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5617 M68K NetBSD m68k-*-netbsd*
5618 PowerPC AIX 4.x powerpc-*-aix*
5619 PowerPC MacOS powerpc-*-macos*
5620 PowerPC Windows NT powerpcle-*-cygwin32
5621 RS/6000 AIX 4.x rs6000-*-aix4*
5625 ARM with RDP protocol arm-*-*
5626 I960 with MON960 i960-*-coff
5627 MIPS VxWorks mips*-*-vxworks*
5628 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5629 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5631 Matra Sparclet sparclet-*-*
5635 The powerpc-eabi configuration now includes the PSIM simulator,
5636 contributed by Andrew Cagney, with assistance from Mike Meissner.
5637 PSIM is a very elaborate model of the PowerPC, including not only
5638 basic instruction set execution, but also details of execution unit
5639 performance and I/O hardware. See sim/ppc/README for more details.
5643 GDB now works with Solaris 2.5.
5645 * Windows 95/NT native
5647 GDB will now work as a native debugger on Windows 95 and Windows NT.
5648 To build it from source, you must use the "gnu-win32" environment,
5649 which uses a DLL to emulate enough of Unix to run the GNU tools.
5650 Further information, binaries, and sources are available at
5651 ftp.cygnus.com, under pub/gnu-win32.
5653 * dont-repeat command
5655 If a user-defined command includes the command `dont-repeat', then the
5656 command will not be repeated if the user just types return. This is
5657 useful if the command is time-consuming to run, so that accidental
5658 extra keystrokes don't run the same command many times.
5660 * Send break instead of ^C
5662 The standard remote protocol now includes an option to send a break
5663 rather than a ^C to the target in order to interrupt it. By default,
5664 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5666 * Remote protocol timeout
5668 The standard remote protocol includes a new variable `remotetimeout'
5669 that allows you to set the number of seconds before GDB gives up trying
5670 to read from the target. The default value is 2.
5672 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5674 By default GDB will automatically keep track of objects as they are
5675 loaded and unloaded by the dynamic linker. By using the command `set
5676 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5677 when shared library events occur, thus allowing you to set breakpoints
5678 in shared libraries which are explicitly loaded by the inferior.
5680 Note this feature does not work on hpux8. On hpux9 you must link
5681 /usr/lib/end.o into your program. This feature should work
5682 automatically on hpux10.
5684 * Irix 5.x hardware watchpoint support
5686 Irix 5 configurations now support the use of hardware watchpoints.
5688 * Mips protocol "SYN garbage limit"
5690 When debugging a Mips target using the `target mips' protocol, you
5691 may set the number of characters that GDB will ignore by setting
5692 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5693 every character. The default value is 1050.
5695 * Recording and replaying remote debug sessions
5697 If you set `remotelogfile' to the name of a file, gdb will write to it
5698 a recording of a remote debug session. This recording may then be
5699 replayed back to gdb using "gdbreplay". See gdbserver/README for
5700 details. This is useful when you have a problem with GDB while doing
5701 remote debugging; you can make a recording of the session and send it
5702 to someone else, who can then recreate the problem.
5704 * Speedups for remote debugging
5706 GDB includes speedups for downloading and stepping MIPS systems using
5707 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5708 and more efficient S-record downloading.
5710 * Memory use reductions and statistics collection
5712 GDB now uses less memory and reports statistics about memory usage.
5713 Try the `maint print statistics' command, for example.
5715 *** Changes in GDB-4.15:
5717 * Psymtabs for XCOFF
5719 The symbol reader for AIX GDB now uses partial symbol tables. This
5720 can greatly improve startup time, especially for large executables.
5722 * Remote targets use caching
5724 Remote targets now use a data cache to speed up communication with the
5725 remote side. The data cache could lead to incorrect results because
5726 it doesn't know about volatile variables, thus making it impossible to
5727 debug targets which use memory mapped I/O devices. `set remotecache
5728 off' turns the the data cache off.
5730 * Remote targets may have threads
5732 The standard remote protocol now includes support for multiple threads
5733 in the target system, using new protocol commands 'H' and 'T'. See
5734 gdb/remote.c for details.
5738 If GDB is configured with `--enable-netrom', then it will include
5739 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5740 acts as though it is a bank of ROM on the target board, but you can
5741 write into it over the network. GDB's support consists only of
5742 support for fast loading into the emulated ROM; to debug, you must use
5743 another protocol, such as standard remote protocol. The usual
5744 sequence is something like
5746 target nrom <netrom-hostname>
5748 target remote <netrom-hostname>:1235
5752 GDB now includes support for the Apple Macintosh, as a host only. It
5753 may be run as either an MPW tool or as a standalone application, and
5754 it can debug through the serial port. All the usual GDB commands are
5755 available, but to the target command, you must supply "serial" as the
5756 device type instead of "/dev/ttyXX". See mpw-README in the main
5757 directory for more information on how to build. The MPW configuration
5758 scripts */mpw-config.in support only a few targets, and only the
5759 mips-idt-ecoff target has been tested.
5763 GDB configuration now uses autoconf. This is not user-visible,
5764 but does simplify configuration and building.
5768 GDB now supports hpux10.
5770 *** Changes in GDB-4.14:
5772 * New native configurations
5774 x86 FreeBSD i[345]86-*-freebsd
5775 x86 NetBSD i[345]86-*-netbsd
5776 NS32k NetBSD ns32k-*-netbsd
5777 Sparc NetBSD sparc-*-netbsd
5781 A29K VxWorks a29k-*-vxworks
5782 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5783 CPU32 EST-300 emulator m68*-*-est*
5784 PowerPC ELF powerpc-*-elf
5787 * Alpha OSF/1 support for procfs
5789 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5790 possible to attach to running processes. As the mounting of the /proc
5791 filesystem is optional on the Alpha, GDB automatically determines
5792 the availability of /proc during startup. This can lead to problems
5793 if /proc is unmounted after GDB has been started.
5795 * Arguments to user-defined commands
5797 User commands may accept up to 10 arguments separated by whitespace.
5798 Arguments are accessed within the user command via $arg0..$arg9. A
5801 print $arg0 + $arg1 + $arg2
5803 To execute the command use:
5806 Defines the command "adder" which prints the sum of its three arguments.
5807 Note the arguments are text substitutions, so they may reference variables,
5808 use complex expressions, or even perform inferior function calls.
5810 * New `if' and `while' commands
5812 This makes it possible to write more sophisticated user-defined
5813 commands. Both commands take a single argument, which is the
5814 expression to evaluate, and must be followed by the commands to
5815 execute, one per line, if the expression is nonzero, the list being
5816 terminated by the word `end'. The `if' command list may include an
5817 `else' word, which causes the following commands to be executed only
5818 if the expression is zero.
5820 * Fortran source language mode
5822 GDB now includes partial support for Fortran 77. It will recognize
5823 Fortran programs and can evaluate a subset of Fortran expressions, but
5824 variables and functions may not be handled correctly. GDB will work
5825 with G77, but does not yet know much about symbols emitted by other
5828 * Better HPUX support
5830 Most debugging facilities now work on dynamic executables for HPPAs
5831 running hpux9 or later. You can attach to running dynamically linked
5832 processes, but by default the dynamic libraries will be read-only, so
5833 for instance you won't be able to put breakpoints in them. To change
5834 that behavior do the following before running the program:
5840 This will cause the libraries to be mapped private and read-write.
5841 To revert to the normal behavior, do this:
5847 You cannot set breakpoints or examine data in the library until after
5848 the library is loaded if the function/data symbols do not have
5851 GDB can now also read debug symbols produced by the HP C compiler on
5852 HPPAs (sorry, no C++, Fortran or 68k support).
5854 * Target byte order now dynamically selectable
5856 You can choose which byte order to use with a target system, via the
5857 commands "set endian big" and "set endian little", and you can see the
5858 current setting by using "show endian". You can also give the command
5859 "set endian auto", in which case GDB will use the byte order
5860 associated with the executable. Currently, only embedded MIPS
5861 configurations support dynamic selection of target byte order.
5863 * New DOS host serial code
5865 This version uses DPMI interrupts to handle buffered I/O, so you
5866 no longer need to run asynctsr when debugging boards connected to
5869 *** Changes in GDB-4.13:
5871 * New "complete" command
5873 This lists all the possible completions for the rest of the line, if it
5874 were to be given as a command itself. This is intended for use by emacs.
5876 * Trailing space optional in prompt
5878 "set prompt" no longer adds a space for you after the prompt you set. This
5879 allows you to set a prompt which ends in a space or one that does not.
5881 * Breakpoint hit counts
5883 "info break" now displays a count of the number of times the breakpoint
5884 has been hit. This is especially useful in conjunction with "ignore"; you
5885 can ignore a large number of breakpoint hits, look at the breakpoint info
5886 to see how many times the breakpoint was hit, then run again, ignoring one
5887 less than that number, and this will get you quickly to the last hit of
5890 * Ability to stop printing at NULL character
5892 "set print null-stop" will cause GDB to stop printing the characters of
5893 an array when the first NULL is encountered. This is useful when large
5894 arrays actually contain only short strings.
5896 * Shared library breakpoints
5898 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5899 breakpoints in shared libraries before the executable is run.
5901 * Hardware watchpoints
5903 There is a new hardware breakpoint for the watch command for sparclite
5904 targets. See gdb/sparclite/hw_breakpoint.note.
5906 Hardware watchpoints are also now supported under GNU/Linux.
5910 Annotations have been added. These are for use with graphical interfaces,
5911 and are still experimental. Currently only gdba.el uses these.
5913 * Improved Irix 5 support
5915 GDB now works properly with Irix 5.2.
5917 * Improved HPPA support
5919 GDB now works properly with the latest GCC and GAS.
5921 * New native configurations
5923 Sequent PTX4 i[34]86-sequent-ptx4
5924 HPPA running OSF/1 hppa*-*-osf*
5925 Atari TT running SVR4 m68*-*-sysv4*
5926 RS/6000 LynxOS rs6000-*-lynxos*
5930 OS/9000 i[34]86-*-os9k
5931 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5934 * Hitachi SH7000 and E7000-PC ICE support
5936 There is now support for communicating with the Hitachi E7000-PC ICE.
5937 This is available automatically when GDB is configured for the SH.
5941 As usual, a variety of small fixes and improvements, both generic
5942 and configuration-specific. See the ChangeLog for more detail.
5944 *** Changes in GDB-4.12:
5946 * Irix 5 is now supported
5950 GDB-4.12 on the HPPA has a number of changes which make it unable
5951 to debug the output from the currently released versions of GCC and
5952 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5953 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5954 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5957 *** Changes in GDB-4.11:
5959 * User visible changes:
5963 The "set remotedebug" option is now consistent between the mips remote
5964 target, remote targets using the gdb-specific protocol, UDI (AMD's
5965 debug protocol for the 29k) and the 88k bug monitor. It is now an
5966 integer specifying a debug level (normally 0 or 1, but 2 means more
5967 debugging info for the mips target).
5969 * DEC Alpha native support
5971 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
5972 debug info, but GDB works fairly well with the DEC compiler and should
5973 work with a future GCC release. See the README file for a few
5974 Alpha-specific notes.
5976 * Preliminary thread implementation
5978 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
5980 * LynxOS native and target support for 386
5982 This release has been hosted on LynxOS 2.2, and also can be configured
5983 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
5986 * Improvements in C++ mangling/demangling.
5988 This release has much better g++ debugging, specifically in name
5989 mangling/demangling, virtual function calls, print virtual table,
5990 call methods, ...etc.
5992 *** Changes in GDB-4.10:
5994 * User visible changes:
5996 Remote debugging using the GDB-specific (`target remote') protocol now
5997 supports the `load' command. This is only useful if you have some
5998 other way of getting the stub to the target system, and you can put it
5999 somewhere in memory where it won't get clobbered by the download.
6001 Filename completion now works.
6003 When run under emacs mode, the "info line" command now causes the
6004 arrow to point to the line specified. Also, "info line" prints
6005 addresses in symbolic form (as well as hex).
6007 All vxworks based targets now support a user settable option, called
6008 vxworks-timeout. This option represents the number of seconds gdb
6009 should wait for responses to rpc's. You might want to use this if
6010 your vxworks target is, perhaps, a slow software simulator or happens
6011 to be on the far side of a thin network line.
6015 This release contains support for using a DEC alpha as a GDB host for
6016 cross debugging. Native alpha debugging is not supported yet.
6019 *** Changes in GDB-4.9:
6023 This is the first GDB release which is accompanied by a matching testsuite.
6024 The testsuite requires installation of dejagnu, which should be available
6025 via ftp from most sites that carry GNU software.
6029 'Cfront' style demangling has had its name changed to 'ARM' style, to
6030 emphasize that it was written from the specifications in the C++ Annotated
6031 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6032 disclaimers, it still generated too much confusion with users attempting to
6033 use gdb with AT&T cfront.
6037 GDB now uses a standard remote interface to a simulator library.
6038 So far, the library contains simulators for the Zilog Z8001/2, the
6039 Hitachi H8/300, H8/500 and Super-H.
6041 * New targets supported
6043 H8/300 simulator h8300-hitachi-hms or h8300hms
6044 H8/500 simulator h8500-hitachi-hms or h8500hms
6045 SH simulator sh-hitachi-hms or sh
6046 Z8000 simulator z8k-zilog-none or z8ksim
6047 IDT MIPS board over serial line mips-idt-ecoff
6049 Cross-debugging to GO32 targets is supported. It requires a custom
6050 version of the i386-stub.c module which is integrated with the
6051 GO32 memory extender.
6053 * New remote protocols
6055 MIPS remote debugging protocol.
6057 * New source languages supported
6059 This version includes preliminary support for Chill, a Pascal like language
6060 used by telecommunications companies. Chill support is also being integrated
6061 into the GNU compiler, but we don't know when it will be publically available.
6064 *** Changes in GDB-4.8:
6066 * HP Precision Architecture supported
6068 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6069 version of this support was available as a set of patches from the
6070 University of Utah. GDB does not support debugging of programs
6071 compiled with the HP compiler, because HP will not document their file
6072 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6073 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6075 Many problems in the preliminary version have been fixed.
6077 * Faster and better demangling
6079 We have improved template demangling and fixed numerous bugs in the GNU style
6080 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6081 character types (wchar_t) are now supported. Demangling of each symbol is now
6082 only done once, and is cached when the symbol table for a file is read in.
6083 This results in a small increase in memory usage for C programs, a moderate
6084 increase in memory usage for C++ programs, and a fantastic speedup in
6087 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6088 from the specifications in the Annotated Reference Manual, which AT&T's
6089 compiler does not actually implement.
6091 * G++ multiple inheritance compiler problem
6093 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6094 inheritance lattices was reworked to properly discover ambiguities. We
6095 recently found an example which causes this new algorithm to fail in a
6096 very subtle way, producing bad debug information for those classes.
6097 The file 'gcc.patch' (in this directory) can be applied to gcc to
6098 circumvent the problem. A future GCC release will contain a complete
6101 The previous G++ debug info problem (mentioned below for the gdb-4.7
6102 release) is fixed in gcc version 2.3.2.
6104 * Improved configure script
6106 The `configure' script will now attempt to guess your system type if
6107 you don't supply a host system type. The old scheme of supplying a
6108 host system triplet is preferable over using this. All the magic is
6109 done in the new `config.guess' script. Examine it for details.
6111 We have also brought our configure script much more in line with the FSF's
6112 version. It now supports the --with-xxx options. In particular,
6113 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6114 The resulting GDB will not be able to read arbitrary object file formats --
6115 only the format ``expected'' to be used on the configured target system.
6116 We hope to make this the default in a future release.
6118 * Documentation improvements
6120 There's new internal documentation on how to modify GDB, and how to
6121 produce clean changes to the code. We implore people to read it
6122 before submitting changes.
6124 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6125 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6126 `info' files are also provided. To build `info' files from scratch,
6127 you will need the latest `makeinfo' release, which will be available in
6128 a future texinfo-X.Y release.
6130 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6131 We're not sure exactly which versions have this problem, but it has
6132 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6133 or better. If that isn't possible, there is a patch in
6134 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6135 around this problem.
6139 GDB now supports array constants that can be used in expressions typed in by
6140 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6141 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6144 The new directory `gdb/sparclite' contains a program that demonstrates
6145 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6147 * New native hosts supported
6149 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6150 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6152 * New targets supported
6154 AMD 29k family via UDI a29k-amd-udi or udi29k
6156 * New file formats supported
6158 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6159 HPUX core files, and SCO 3.2v2 core files.
6163 Attaching to processes now works again; thanks for the many bug reports.
6165 We have also stomped on a bunch of core dumps caused by
6166 printf_filtered("%s") problems.
6168 We eliminated a copyright problem on the rpc and ptrace header files
6169 for VxWorks, which was discovered at the last minute during the 4.7
6170 release. You should now be able to build a VxWorks GDB.
6172 You can now interrupt gdb while an attached process is running. This
6173 will cause the attached process to stop, and give control back to GDB.
6175 We fixed problems caused by using too many file descriptors
6176 for reading symbols from object files and libraries. This was
6177 especially a problem for programs that used many (~100) shared
6180 The `step' command now only enters a subroutine if there is line number
6181 information for the subroutine. Otherwise it acts like the `next'
6182 command. Previously, `step' would enter subroutines if there was
6183 any debugging information about the routine. This avoids problems
6184 when using `cc -g1' on MIPS machines.
6186 * Internal improvements
6188 GDB's internal interfaces have been improved to make it easier to support
6189 debugging of multiple languages in the future.
6191 GDB now uses a common structure for symbol information internally.
6192 Minimal symbols (derived from linkage symbols in object files), partial
6193 symbols (from a quick scan of debug information), and full symbols
6194 contain a common subset of information, making it easier to write
6195 shared code that handles any of them.
6197 * New command line options
6199 We now accept --silent as an alias for --quiet.
6203 The memory-mapped-malloc library is now licensed under the GNU Library
6204 General Public License.
6206 *** Changes in GDB-4.7:
6208 * Host/native/target split
6210 GDB has had some major internal surgery to untangle the support for
6211 hosts and remote targets. Now, when you configure GDB for a remote
6212 target, it will no longer load in all of the support for debugging
6213 local programs on the host. When fully completed and tested, this will
6214 ensure that arbitrary host/target combinations are possible.
6216 The primary conceptual shift is to separate the non-portable code in
6217 GDB into three categories. Host specific code is required any time GDB
6218 is compiled on that host, regardless of the target. Target specific
6219 code relates to the peculiarities of the target, but can be compiled on
6220 any host. Native specific code is everything else: it can only be
6221 built when the host and target are the same system. Child process
6222 handling and core file support are two common `native' examples.
6224 GDB's use of /proc for controlling Unix child processes is now cleaner.
6225 It has been split out into a single module under the `target_ops' vector,
6226 plus two native-dependent functions for each system that uses /proc.
6228 * New hosts supported
6230 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6231 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6232 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6234 * New targets supported
6236 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6237 68030 and CPU32 m68030-*-*, m68332-*-*
6239 * New native hosts supported
6241 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6242 (386bsd is not well tested yet)
6243 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6245 * New file formats supported
6247 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6248 supports reading of `a.out.adobe' object files, which are an a.out
6249 format extended with minimal information about multiple sections.
6253 `show copying' is the same as the old `info copying'.
6254 `show warranty' is the same as `info warrantee'.
6255 These were renamed for consistency. The old commands continue to work.
6257 `info handle' is a new alias for `info signals'.
6259 You can now define pre-command hooks, which attach arbitrary command
6260 scripts to any command. The commands in the hook will be executed
6261 prior to the user's command. You can also create a hook which will be
6262 executed whenever the program stops. See gdb.texinfo.
6266 We now deal with Cfront style name mangling, and can even extract type
6267 info from mangled symbols. GDB can automatically figure out which
6268 symbol mangling style your C++ compiler uses.
6270 Calling of methods and virtual functions has been improved as well.
6274 The crash that occured when debugging Sun Ansi-C compiled binaries is
6275 fixed. This was due to mishandling of the extra N_SO stabs output
6278 We also finally got Ultrix 4.2 running in house, and fixed core file
6279 support, with help from a dozen people on the net.
6281 John M. Farrell discovered that the reason that single-stepping was so
6282 slow on all of the Mips based platforms (primarily SGI and DEC) was
6283 that we were trying to demangle and lookup a symbol used for internal
6284 purposes on every instruction that was being stepped through. Changing
6285 the name of that symbol so that it couldn't be mistaken for a C++
6286 mangled symbol sped things up a great deal.
6288 Rich Pixley sped up symbol lookups in general by getting much smarter
6289 about when C++ symbol mangling is necessary. This should make symbol
6290 completion (TAB on the command line) much faster. It's not as fast as
6291 we'd like, but it's significantly faster than gdb-4.6.
6295 A new user controllable variable 'call_scratch_address' can
6296 specify the location of a scratch area to be used when GDB
6297 calls a function in the target. This is necessary because the
6298 usual method of putting the scratch area on the stack does not work
6299 in systems that have separate instruction and data spaces.
6301 We integrated changes to support the 29k UDI (Universal Debugger
6302 Interface), but discovered at the last minute that we didn't have all
6303 of the appropriate copyright paperwork. We are working with AMD to
6304 resolve this, and hope to have it available soon.
6308 We have sped up the remote serial line protocol, especially for targets
6309 with lots of registers. It now supports a new `expedited status' ('T')
6310 message which can be used in place of the existing 'S' status message.
6311 This allows the remote stub to send only the registers that GDB
6312 needs to make a quick decision about single-stepping or conditional
6313 breakpoints, eliminating the need to fetch the entire register set for
6314 each instruction being stepped through.
6316 The GDB remote serial protocol now implements a write-through cache for
6317 registers, only re-reading the registers if the target has run.
6319 There is also a new remote serial stub for SPARC processors. You can
6320 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6321 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6322 processor with a serial port.
6326 Configure.in files have become much easier to read and modify. A new
6327 `table driven' format makes it more obvious what configurations are
6328 supported, and what files each one uses.
6332 There is a new opcodes library which will eventually contain all of the
6333 disassembly routines and opcode tables. At present, it only contains
6334 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6335 disassembler (binutils/objdump) to share these routines.
6337 The libiberty library is now copylefted under the GNU Library General
6338 Public License. This allows more liberal use, and was done so libg++
6339 can use it. This makes no difference to GDB, since the Library License
6340 grants all the rights from the General Public License.
6344 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6345 reference to the stabs symbol info used by the debugger. It is (as far
6346 as we know) the only published document on this fascinating topic. We
6347 encourage you to read it, compare it to the stabs information on your
6348 system, and send improvements on the document in general (to
6349 bug-gdb@prep.ai.mit.edu).
6351 And, of course, many bugs have been fixed.
6354 *** Changes in GDB-4.6:
6356 * Better support for C++ function names
6358 GDB now accepts as input the "demangled form" of C++ overloaded function
6359 names and member function names, and can do command completion on such names
6360 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6361 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6362 Make use of command completion, it is your friend.
6364 GDB also now accepts a variety of C++ mangled symbol formats. They are
6365 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6366 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6367 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6368 for the list of formats.
6370 * G++ symbol mangling problem
6372 Recent versions of gcc have a bug in how they emit debugging information for
6373 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6374 directory) can be applied to gcc to fix the problem. Alternatively, if you
6375 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6376 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6377 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6380 * New 'maintenance' command
6382 All of the commands related to hacking GDB internals have been moved out of
6383 the main command set, and now live behind the 'maintenance' command. This
6384 can also be abbreviated as 'mt'. The following changes were made:
6386 dump-me -> maintenance dump-me
6387 info all-breakpoints -> maintenance info breakpoints
6388 printmsyms -> maintenance print msyms
6389 printobjfiles -> maintenance print objfiles
6390 printpsyms -> maintenance print psymbols
6391 printsyms -> maintenance print symbols
6393 The following commands are new:
6395 maintenance demangle Call internal GDB demangler routine to
6396 demangle a C++ link name and prints the result.
6397 maintenance print type Print a type chain for a given symbol
6399 * Change to .gdbinit file processing
6401 We now read the $HOME/.gdbinit file before processing the argv arguments
6402 (e.g. reading symbol files or core files). This allows global parameters to
6403 be set, which will apply during the symbol reading. The ./.gdbinit is still
6404 read after argv processing.
6406 * New hosts supported
6408 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6410 GNU/Linux support i386-unknown-linux or linux
6412 We are also including code to support the HP/PA running BSD and HPUX. This
6413 is almost guaranteed not to work, as we didn't have time to test or build it
6414 for this release. We are including it so that the more adventurous (or
6415 masochistic) of you can play with it. We also had major problems with the
6416 fact that the compiler that we got from HP doesn't support the -g option.
6419 * New targets supported
6421 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6423 * More smarts about finding #include files
6425 GDB now remembers the compilation directory for all include files, and for
6426 all files from which C is generated (like yacc and lex sources). This
6427 greatly improves GDB's ability to find yacc/lex sources, and include files,
6428 especially if you are debugging your program from a directory different from
6429 the one that contains your sources.
6431 We also fixed a bug which caused difficulty with listing and setting
6432 breakpoints in include files which contain C code. (In the past, you had to
6433 try twice in order to list an include file that you hadn't looked at before.)
6435 * Interesting infernals change
6437 GDB now deals with arbitrary numbers of sections, where the symbols for each
6438 section must be relocated relative to that section's landing place in the
6439 target's address space. This work was needed to support ELF with embedded
6440 stabs used by Solaris-2.0.
6442 * Bug fixes (of course!)
6444 There have been loads of fixes for the following things:
6445 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6446 i960, stabs, DOS(GO32), procfs, etc...
6448 See the ChangeLog for details.
6450 *** Changes in GDB-4.5:
6452 * New machines supported (host and target)
6454 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6456 SGI Irix-4.x mips-sgi-irix4 or iris4
6458 * New malloc package
6460 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6461 Mmalloc is capable of handling mutiple heaps of memory. It is also
6462 capable of saving a heap to a file, and then mapping it back in later.
6463 This can be used to greatly speedup the startup of GDB by using a
6464 pre-parsed symbol table which lives in a mmalloc managed heap. For
6465 more details, please read mmalloc/mmalloc.texi.
6469 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6470 'help info proc' for details.
6472 * MIPS ecoff symbol table format
6474 The code that reads MIPS symbol table format is now supported on all hosts.
6475 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6478 * File name changes for MS-DOS
6480 Many files in the config directories have been renamed to make it easier to
6481 support GDB on MS-DOSe systems (which have very restrictive file name
6482 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6483 environment) is close to working but has some remaining problems. Note
6484 that debugging of DOS programs is not supported, due to limitations
6485 in the ``operating system'', but it can be used to host cross-debugging.
6487 * Cross byte order fixes
6489 Many fixes have been made to support cross debugging of Sparc and MIPS
6490 targets from hosts whose byte order differs.
6492 * New -mapped and -readnow options
6494 If memory-mapped files are available on your system through the 'mmap'
6495 system call, you can use the -mapped option on the `file' or
6496 `symbol-file' commands to cause GDB to write the symbols from your
6497 program into a reusable file. If the program you are debugging is
6498 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6499 Future GDB debugging sessions will notice the presence of this file,
6500 and will quickly map in symbol information from it, rather than reading
6501 the symbol table from the executable program. Using the '-mapped'
6502 option in a GDB `file' or `symbol-file' command has the same effect as
6503 starting GDB with the '-mapped' command-line option.
6505 You can cause GDB to read the entire symbol table immediately by using
6506 the '-readnow' option with any of the commands that load symbol table
6507 information (or on the GDB command line). This makes the command
6508 slower, but makes future operations faster.
6510 The -mapped and -readnow options are typically combined in order to
6511 build a `fred.syms' file that contains complete symbol information.
6512 A simple GDB invocation to do nothing but build a `.syms' file for future
6515 gdb -batch -nx -mapped -readnow programname
6517 The `.syms' file is specific to the host machine on which GDB is run.
6518 It holds an exact image of GDB's internal symbol table. It cannot be
6519 shared across multiple host platforms.
6521 * longjmp() handling
6523 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6524 siglongjmp() without losing control. This feature has not yet been ported to
6525 all systems. It currently works on many 386 platforms, all MIPS-based
6526 platforms (SGI, DECstation, etc), and Sun3/4.
6530 Preliminary work has been put in to support the new Solaris OS from Sun. At
6531 this time, it can control and debug processes, but it is not capable of
6536 As always, many many bug fixes. The major areas were with g++, and mipsread.
6537 People using the MIPS-based platforms should experience fewer mysterious
6538 crashes and trashed symbol tables.
6540 *** Changes in GDB-4.4:
6542 * New machines supported (host and target)
6544 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6546 BSD Reno on Vax vax-dec-bsd
6547 Ultrix on Vax vax-dec-ultrix
6549 * New machines supported (target)
6551 AMD 29000 embedded, using EBMON a29k-none-none
6555 GDB continues to improve its handling of C++. `References' work better.
6556 The demangler has also been improved, and now deals with symbols mangled as
6557 per the Annotated C++ Reference Guide.
6559 GDB also now handles `stabs' symbol information embedded in MIPS
6560 `ecoff' symbol tables. Since the ecoff format was not easily
6561 extensible to handle new languages such as C++, this appeared to be a
6562 good way to put C++ debugging info into MIPS binaries. This option
6563 will be supported in the GNU C compiler, version 2, when it is
6566 * New features for SVR4
6568 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6569 shared libraries. Debugging dynamically linked programs should present
6570 only minor differences from debugging statically linked programs.
6572 The `info proc' command will print out information about any process
6573 on an SVR4 system (including the one you are debugging). At the moment,
6574 it prints the address mappings of the process.
6576 If you bring up GDB on another SVR4 system, please send mail to
6577 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6579 * Better dynamic linking support in SunOS
6581 Reading symbols from shared libraries which contain debugging symbols
6582 now works properly. However, there remain issues such as automatic
6583 skipping of `transfer vector' code during function calls, which
6584 make it harder to debug code in a shared library, than to debug the
6585 same code linked statically.
6589 GDB is now using the latest `getopt' routines from the FSF. This
6590 version accepts the -- prefix for options with long names. GDB will
6591 continue to accept the old forms (-option and +option) as well.
6592 Various single letter abbreviations for options have been explicity
6593 added to the option table so that they won't get overshadowed in the
6594 future by other options that begin with the same letter.
6598 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6599 Many assorted bugs have been handled. Many more remain to be handled.
6600 See the various ChangeLog files (primarily in gdb and bfd) for details.
6603 *** Changes in GDB-4.3:
6605 * New machines supported (host and target)
6607 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6608 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6609 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6611 * Almost SCO Unix support
6613 We had hoped to support:
6614 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6615 (except for core file support), but we discovered very late in the release
6616 that it has problems with process groups that render gdb unusable. Sorry
6617 about that. I encourage people to fix it and post the fixes.
6619 * Preliminary ELF and DWARF support
6621 GDB can read ELF object files on System V Release 4, and can handle
6622 debugging records for C, in DWARF format, in ELF files. This support
6623 is preliminary. If you bring up GDB on another SVR4 system, please
6624 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6629 GDB now uses the latest `readline' library. One user-visible change
6630 is that two tabs will list possible command completions, which previously
6631 required typing M-? (meta-question mark, or ESC ?).
6635 The `stepi' bug that many of you noticed has been squashed.
6636 Many bugs in C++ have been handled. Many more remain to be handled.
6637 See the various ChangeLog files (primarily in gdb and bfd) for details.
6639 * State of the MIPS world (in case you wondered):
6641 GDB can understand the symbol tables emitted by the compilers
6642 supplied by most vendors of MIPS-based machines, including DEC. These
6643 symbol tables are in a format that essentially nobody else uses.
6645 Some versions of gcc come with an assembler post-processor called
6646 mips-tfile. This program is required if you want to do source-level
6647 debugging of gcc-compiled programs. I believe FSF does not ship
6648 mips-tfile with gcc version 1, but it will eventually come with gcc
6651 Debugging of g++ output remains a problem. g++ version 1.xx does not
6652 really support it at all. (If you're lucky, you should be able to get
6653 line numbers and stack traces to work, but no parameters or local
6654 variables.) With some work it should be possible to improve the
6657 When gcc version 2 is released, you will have somewhat better luck.
6658 However, even then you will get confusing results for inheritance and
6661 We will eventually provide full debugging of g++ output on
6662 DECstations. This will probably involve some kind of stabs-in-ecoff
6663 encapulation, but the details have not been worked out yet.
6666 *** Changes in GDB-4.2:
6668 * Improved configuration
6670 Only one copy of `configure' exists now, and it is not self-modifying.
6671 Porting BFD is simpler.
6675 The `step' and `next' commands now only stop at the first instruction
6676 of a source line. This prevents the multiple stops that used to occur
6677 in switch statements, for-loops, etc. `Step' continues to stop if a
6678 function that has debugging information is called within the line.
6682 Lots of small bugs fixed. More remain.
6684 * New host supported (not target)
6686 Intel 386 PC clone running Mach i386-none-mach
6689 *** Changes in GDB-4.1:
6691 * Multiple source language support
6693 GDB now has internal scaffolding to handle several source languages.
6694 It determines the type of each source file from its filename extension,
6695 and will switch expression parsing and number formatting to match the
6696 language of the function in the currently selected stack frame.
6697 You can also specifically set the language to be used, with
6698 `set language c' or `set language modula-2'.
6702 GDB now has preliminary support for the GNU Modula-2 compiler,
6703 currently under development at the State University of New York at
6704 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6705 continue through the fall of 1991 and into 1992.
6707 Other Modula-2 compilers are currently not supported, and attempting to
6708 debug programs compiled with them will likely result in an error as the
6709 symbol table is read. Feel free to work on it, though!
6711 There are hooks in GDB for strict type checking and range checking,
6712 in the `Modula-2 philosophy', but they do not currently work.
6716 GDB can now write to executable and core files (e.g. patch
6717 a variable's value). You must turn this switch on, specify
6718 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6719 by assigning a new value to a variable. Modifications take
6722 * Automatic SunOS shared library reading
6724 When you run your program, GDB automatically determines where its
6725 shared libraries (if any) have been loaded, and reads their symbols.
6726 The `share' command is no longer needed. This also works when
6727 examining core files.
6731 You can specify the number of lines that the `list' command shows.
6734 * New machines supported (host and target)
6736 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6737 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6738 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6740 * New hosts supported (not targets)
6742 IBM RT/PC: romp-ibm-aix or rtpc
6744 * New targets supported (not hosts)
6746 AMD 29000 embedded with COFF a29k-none-coff
6747 AMD 29000 embedded with a.out a29k-none-aout
6748 Ultracomputer remote kernel debug a29k-nyu-kern
6750 * New remote interfaces
6756 *** Changes in GDB-4.0:
6760 Wide output is wrapped at good places to make the output more readable.
6762 Gdb now supports cross-debugging from a host machine of one type to a
6763 target machine of another type. Communication with the target system
6764 is over serial lines. The ``target'' command handles connecting to the
6765 remote system; the ``load'' command will download a program into the
6766 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6767 also supports debugging of realtime processes running under VxWorks,
6768 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6769 stub on the target system.
6771 New CPUs supported include the AMD 29000 and Intel 960.
6773 GDB now reads object files and symbol tables via a ``binary file''
6774 library, which allows a single copy of GDB to debug programs of multiple
6775 object file types such as a.out and coff.
6777 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6778 refcard.dvi and refcard.ps are available to format it).
6781 * Control-Variable user interface simplified
6783 All variables that control the operation of the debugger can be set
6784 by the ``set'' command, and displayed by the ``show'' command.
6786 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6787 ``Show prompt'' produces the response:
6788 Gdb's prompt is new-gdb=>.
6790 What follows are the NEW set commands. The command ``help set'' will
6791 print a complete list of old and new set commands. ``help set FOO''
6792 will give a longer description of the variable FOO. ``show'' will show
6793 all of the variable descriptions and their current settings.
6795 confirm on/off: Enables warning questions for operations that are
6796 hard to recover from, e.g. rerunning the program while
6797 it is already running. Default is ON.
6799 editing on/off: Enables EMACS style command line editing
6800 of input. Previous lines can be recalled with
6801 control-P, the current line can be edited with control-B,
6802 you can search for commands with control-R, etc.
6805 history filename NAME: NAME is where the gdb command history
6806 will be stored. The default is .gdb_history,
6807 or the value of the environment variable
6810 history size N: The size, in commands, of the command history. The
6811 default is 256, or the value of the environment variable
6814 history save on/off: If this value is set to ON, the history file will
6815 be saved after exiting gdb. If set to OFF, the
6816 file will not be saved. The default is OFF.
6818 history expansion on/off: If this value is set to ON, then csh-like
6819 history expansion will be performed on
6820 command line input. The default is OFF.
6822 radix N: Sets the default radix for input and output. It can be set
6823 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6824 in the current radix, so "set radix 10" is always a no-op.
6826 height N: This integer value is the number of lines on a page. Default
6827 is 24, the current `stty rows'' setting, or the ``li#''
6828 setting from the termcap entry matching the environment
6831 width N: This integer value is the number of characters on a line.
6832 Default is 80, the current `stty cols'' setting, or the ``co#''
6833 setting from the termcap entry matching the environment
6836 Note: ``set screensize'' is obsolete. Use ``set height'' and
6837 ``set width'' instead.
6839 print address on/off: Print memory addresses in various command displays,
6840 such as stack traces and structure values. Gdb looks
6841 more ``symbolic'' if you turn this off; it looks more
6842 ``machine level'' with it on. Default is ON.
6844 print array on/off: Prettyprint arrays. New convenient format! Default
6847 print demangle on/off: Print C++ symbols in "source" form if on,
6850 print asm-demangle on/off: Same, for assembler level printouts
6853 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6856 * Support for Epoch Environment.
6858 The epoch environment is a version of Emacs v18 with windowing. One
6859 new command, ``inspect'', is identical to ``print'', except that if you
6860 are running in the epoch environment, the value is printed in its own
6864 * Support for Shared Libraries
6866 GDB can now debug programs and core files that use SunOS shared libraries.
6867 Symbols from a shared library cannot be referenced
6868 before the shared library has been linked with the program (this
6869 happens after you type ``run'' and before the function main() is entered).
6870 At any time after this linking (including when examining core files
6871 from dynamically linked programs), gdb reads the symbols from each
6872 shared library when you type the ``sharedlibrary'' command.
6873 It can be abbreviated ``share''.
6875 sharedlibrary REGEXP: Load shared object library symbols for files
6876 matching a unix regular expression. No argument
6877 indicates to load symbols for all shared libraries.
6879 info sharedlibrary: Status of loaded shared libraries.
6884 A watchpoint stops execution of a program whenever the value of an
6885 expression changes. Checking for this slows down execution
6886 tremendously whenever you are in the scope of the expression, but is
6887 quite useful for catching tough ``bit-spreader'' or pointer misuse
6888 problems. Some machines such as the 386 have hardware for doing this
6889 more quickly, and future versions of gdb will use this hardware.
6891 watch EXP: Set a watchpoint (breakpoint) for an expression.
6893 info watchpoints: Information about your watchpoints.
6895 delete N: Deletes watchpoint number N (same as breakpoints).
6896 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6897 enable N: Re-enables watchpoint number N (same as breakpoints).
6900 * C++ multiple inheritance
6902 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6905 * C++ exception handling
6907 Gdb now supports limited C++ exception handling. Besides the existing
6908 ability to breakpoint on an exception handler, gdb can breakpoint on
6909 the raising of an exception (before the stack is peeled back to the
6912 catch FOO: If there is a FOO exception handler in the dynamic scope,
6913 set a breakpoint to catch exceptions which may be raised there.
6914 Multiple exceptions (``catch foo bar baz'') may be caught.
6916 info catch: Lists all exceptions which may be caught in the
6917 current stack frame.
6920 * Minor command changes
6922 The command ``call func (arg, arg, ...)'' now acts like the print
6923 command, except it does not print or save a value if the function's result
6924 is void. This is similar to dbx usage.
6926 The ``up'' and ``down'' commands now always print the frame they end up
6927 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6928 frames without printing.
6930 * New directory command
6932 'dir' now adds directories to the FRONT of the source search path.
6933 The path starts off empty. Source files that contain debug information
6934 about the directory in which they were compiled can be found even
6935 with an empty path; Sun CC and GCC include this information. If GDB can't
6936 find your source file in the current directory, type "dir .".
6938 * Configuring GDB for compilation
6940 For normal use, type ``./configure host''. See README or gdb.texinfo
6943 GDB now handles cross debugging. If you are remotely debugging between
6944 two different machines, type ``./configure host -target=targ''.
6945 Host is the machine where GDB will run; targ is the machine
6946 where the program that you are debugging will run.