1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.1
6 * The commands 'info variables/functions/types' now show the source line
7 numbers of symbol definitions when available.
9 * 'info proc' now works on running processes on FreeBSD systems and core
10 files created on FreeBSD systems.
12 * C expressions can now use _Alignof, and C++ expressions can now use
19 Control display of debugging info regarding the FreeBSD native target.
21 set|show varsize-limit
22 This new setting allows the user to control the maximum size of Ada
23 objects being printed when those objects have a variable type,
24 instead of that maximum size being hardcoded to 65536 bytes.
26 set|show record btrace cpu
27 Controls the processor to be used for enabling errata workarounds for
32 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
34 ** The commands attached to a breakpoint can be set by assigning to
35 the breakpoint's "commands" field.
39 RiscV ELF riscv*-*-elf
41 * Removed targets and native configurations
43 m88k running OpenBSD m88*-*-openbsd*
44 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
45 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
46 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
48 * Aarch64/Linux hardware watchpoints improvements
50 Hardware watchpoints on unaligned addresses are now properly
51 supported when running Linux kernel 4.10 or higher: read and access
52 watchpoints are no longer spuriously missed, and all watchpoints
53 lengths between 1 and 8 bytes are supported. On older kernels,
54 watchpoints set on unaligned addresses are no longer missed, with
55 the tradeoff that there is a possibility of false hits being
58 *** Changes in GDB 8.1
60 * GDB now supports dynamically creating arbitrary register groups specified
61 in XML target descriptions. This allows for finer grain grouping of
62 registers on systems with a large amount of registers.
64 * The 'ptype' command now accepts a '/o' flag, which prints the
65 offsets and sizes of fields in a struct, like the pahole(1) tool.
67 * New "--readnever" command line option instructs GDB to not read each
68 symbol file's symbolic debug information. This makes startup faster
69 but at the expense of not being able to perform symbolic debugging.
70 This option is intended for use cases where symbolic debugging will
71 not be used, e.g., when you only need to dump the debuggee's core.
73 * GDB now uses the GNU MPFR library, if available, to emulate target
74 floating-point arithmetic during expression evaluation when the target
75 uses different floating-point formats than the host. At least version
76 3.1 of GNU MPFR is required.
78 * GDB now supports access to the guarded-storage-control registers and the
79 software-based guarded-storage broadcast control registers on IBM z14.
81 * On Unix systems, GDB now supports transmitting environment variables
82 that are to be set or unset to GDBserver. These variables will
83 affect the environment to be passed to the remote inferior.
85 To inform GDB of environment variables that are to be transmitted to
86 GDBserver, use the "set environment" command. Only user set
87 environment variables are sent to GDBserver.
89 To inform GDB of environment variables that are to be unset before
90 the remote inferior is started by the GDBserver, use the "unset
93 * Completion improvements
95 ** GDB can now complete function parameters in linespecs and
96 explicit locations without quoting. When setting breakpoints,
97 quoting around functions names to help with TAB-completion is
98 generally no longer necessary. For example, this now completes
101 (gdb) b function(in[TAB]
102 (gdb) b function(int)
104 Related, GDB is no longer confused with completing functions in
105 C++ anonymous namespaces:
108 (gdb) b (anonymous namespace)::[TAB][TAB]
109 (anonymous namespace)::a_function()
110 (anonymous namespace)::b_function()
112 ** GDB now has much improved linespec and explicit locations TAB
113 completion support, that better understands what you're
114 completing and offers better suggestions. For example, GDB no
115 longer offers data symbols as possible completions when you're
116 setting a breakpoint.
118 ** GDB now TAB-completes label symbol names.
120 ** The "complete" command now mimics TAB completion accurately.
122 * New command line options (gcore)
125 Dump all memory mappings.
127 * Breakpoints on C++ functions are now set on all scopes by default
129 By default, breakpoints on functions/methods are now interpreted as
130 specifying all functions with the given name ignoring missing
131 leading scopes (namespaces and classes).
133 For example, assuming a C++ program with symbols named:
138 both commands "break func()" and "break B::func()" set a breakpoint
141 You can use the new flag "-qualified" to override this. This makes
142 GDB interpret the specified function name as a complete
143 fully-qualified name instead. For example, using the same C++
144 program, the "break -q B::func" command sets a breakpoint on
145 "B::func", only. A parameter has been added to the Python
146 gdb.Breakpoint constructor to achieve the same result when creating
147 a breakpoint from Python.
149 * Breakpoints on functions marked with C++ ABI tags
151 GDB can now set breakpoints on functions marked with C++ ABI tags
152 (e.g., [abi:cxx11]). See here for a description of ABI tags:
153 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
155 Functions with a C++11 abi tag are demangled/displayed like this:
157 function[abi:cxx11](int)
160 You can now set a breakpoint on such functions simply as if they had
163 (gdb) b function(int)
165 Or if you need to disambiguate between tags, like:
167 (gdb) b function[abi:other_tag](int)
169 Tab completion was adjusted accordingly as well.
173 ** New events gdb.new_inferior, gdb.inferior_deleted, and
174 gdb.new_thread are emitted. See the manual for further
175 description of these.
177 ** A new function, "gdb.rbreak" has been added to the Python API.
178 This function allows the setting of a large number of breakpoints
179 via a regex pattern in Python. See the manual for further details.
181 ** Python breakpoints can now accept explicit locations. See the
182 manual for a further description of this feature.
185 * New features in the GDB remote stub, GDBserver
187 ** GDBserver is now able to start inferior processes with a
188 specified initial working directory.
190 The user can set the desired working directory to be used from
191 GDB using the new "set cwd" command.
193 ** New "--selftest" command line option runs some GDBserver self
194 tests. These self tests are disabled in releases.
196 ** On Unix systems, GDBserver now does globbing expansion and variable
197 substitution in inferior command line arguments.
199 This is done by starting inferiors using a shell, like GDB does.
200 See "set startup-with-shell" in the user manual for how to disable
201 this from GDB when using "target extended-remote". When using
202 "target remote", you can disable the startup with shell by using the
203 new "--no-startup-with-shell" GDBserver command line option.
205 ** On Unix systems, GDBserver now supports receiving environment
206 variables that are to be set or unset from GDB. These variables
207 will affect the environment to be passed to the inferior.
209 * When catching an Ada exception raised with a message, GDB now prints
210 the message in the catchpoint hit notification. In GDB/MI mode, that
211 information is provided as an extra field named "exception-message"
212 in the *stopped notification.
214 * Trait objects can now be inspected When debugging Rust code. This
215 requires compiler support which will appear in Rust 1.24.
219 QEnvironmentHexEncoded
220 Inform GDBserver of an environment variable that is to be passed to
221 the inferior when starting it.
224 Inform GDBserver of an environment variable that is to be unset
225 before starting the remote inferior.
228 Inform GDBserver that the environment should be reset (i.e.,
229 user-set environment variables should be unset).
232 Indicates whether the inferior must be started with a shell or not.
235 Tell GDBserver that the inferior to be started should use a specific
238 * The "maintenance print c-tdesc" command now takes an optional
239 argument which is the file name of XML target description.
241 * The "maintenance selftest" command now takes an optional argument to
242 filter the tests to be run.
244 * The "enable", and "disable" commands now accept a range of
245 breakpoint locations, e.g. "enable 1.3-5".
250 Set and show the current working directory for the inferior.
253 Set and show compilation command used for compiling and injecting code
254 with the 'compile' commands.
256 set debug separate-debug-file
257 show debug separate-debug-file
258 Control the display of debug output about separate debug file search.
260 set dump-excluded-mappings
261 show dump-excluded-mappings
262 Control whether mappings marked with the VM_DONTDUMP flag should be
263 dumped when generating a core file.
266 List the registered selftests.
269 Start the debugged program stopping at the first instruction.
272 Control display of debugging messages related to OpenRISC targets.
274 set|show print type nested-type-limit
275 Set and show the limit of nesting level for nested types that the
276 type printer will show.
278 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
281 * Safer/improved support for debugging with no debug info
283 GDB no longer assumes functions with no debug information return
286 This means that GDB now refuses to call such functions unless you
287 tell it the function's type, by either casting the call to the
288 declared return type, or by casting the function to a function
289 pointer of the right type, and calling that:
291 (gdb) p getenv ("PATH")
292 'getenv' has unknown return type; cast the call to its declared return type
293 (gdb) p (char *) getenv ("PATH")
294 $1 = 0x7fffffffe "/usr/local/bin:/"...
295 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
296 $2 = 0x7fffffffe "/usr/local/bin:/"...
298 Similarly, GDB no longer assumes that global variables with no debug
299 info have type 'int', and refuses to print the variable's value
300 unless you tell it the variable's type:
303 'var' has unknown type; cast it to its declared type
307 * New native configurations
309 FreeBSD/aarch64 aarch64*-*-freebsd*
310 FreeBSD/arm arm*-*-freebsd*
314 FreeBSD/aarch64 aarch64*-*-freebsd*
315 FreeBSD/arm arm*-*-freebsd*
316 OpenRISC ELF or1k*-*-elf
318 * Removed targets and native configurations
320 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
322 *** Changes in GDB 8.0
324 * GDB now supports access to the PKU register on GNU/Linux. The register is
325 added by the Memory Protection Keys for Userspace feature which will be
326 available in future Intel CPUs.
328 * GDB now supports C++11 rvalue references.
332 ** New functions to start, stop and access a running btrace recording.
333 ** Rvalue references are now supported in gdb.Type.
335 * GDB now supports recording and replaying rdrand and rdseed Intel 64
338 * Building GDB and GDBserver now requires a C++11 compiler.
340 For example, GCC 4.8 or later.
342 It is no longer possible to build GDB or GDBserver with a C
343 compiler. The --disable-build-with-cxx configure option has been
346 * Building GDB and GDBserver now requires GNU make >= 3.81.
348 It is no longer supported to build GDB or GDBserver with another
349 implementation of the make program or an earlier version of GNU make.
351 * Native debugging on MS-Windows supports command-line redirection
353 Command-line arguments used for starting programs on MS-Windows can
354 now include redirection symbols supported by native Windows shells,
355 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
356 as "run", "start", and "set args", as well as the corresponding MI
359 * Support for thread names on MS-Windows.
361 GDB now catches and handles the special exception that programs
362 running on MS-Windows use to assign names to threads in the
365 * Support for Java programs compiled with gcj has been removed.
367 * User commands now accept an unlimited number of arguments.
368 Previously, only up to 10 was accepted.
370 * The "eval" command now expands user-defined command arguments.
372 This makes it easier to process a variable number of arguments:
377 eval "print $arg%d", $i
382 * Target descriptions can now describe registers for sparc32 and sparc64.
384 * GDB now supports DWARF version 5 (debug information format).
385 Its .debug_names index is not yet supported.
387 * New native configurations
389 FreeBSD/mips mips*-*-freebsd
393 Synopsys ARC arc*-*-elf32
394 FreeBSD/mips mips*-*-freebsd
396 * Removed targets and native configurations
398 Alpha running FreeBSD alpha*-*-freebsd*
399 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
404 Erases all the flash memory regions reported by the target.
406 maint print arc arc-instruction address
407 Print internal disassembler information about instruction at a given address.
411 set disassembler-options
412 show disassembler-options
413 Controls the passing of target specific information to the disassembler.
414 If it is necessary to specify more than one disassembler option then
415 multiple options can be placed together into a comma separated list.
416 The default value is the empty string. Currently, the only supported
417 targets are ARM, PowerPC and S/390.
422 Erases all the flash memory regions reported by the target. This is
423 equivalent to the CLI command flash-erase.
425 -file-list-shared-libraries
426 List the shared libraries in the program. This is
427 equivalent to the CLI command "info shared".
430 Catchpoints stopping the program when Ada exceptions are
431 handled. This is equivalent to the CLI command "catch handlers".
433 *** Changes in GDB 7.12
435 * GDB and GDBserver now build with a C++ compiler by default.
437 The --enable-build-with-cxx configure option is now enabled by
438 default. One must now explicitly configure with
439 --disable-build-with-cxx in order to build with a C compiler. This
440 option will be removed in a future release.
442 * GDBserver now supports recording btrace without maintaining an active
445 * GDB now supports a negative repeat count in the 'x' command to examine
446 memory backward from the given address. For example:
449 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
450 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
451 (gdb) x/-5i 0x0000000000400580
452 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
453 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
454 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
455 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
456 0x40057b <main(int, char**)+25>:
457 callq 0x400536 <Func1(int, char const*)>
459 * Fortran: Support structures with fields of dynamic types and
460 arrays of dynamic types.
462 * The symbol dumping maintenance commands have new syntax.
463 maint print symbols [-pc address] [--] [filename]
464 maint print symbols [-objfile objfile] [-source source] [--] [filename]
465 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
466 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
467 maint print msymbols [-objfile objfile] [--] [filename]
469 * GDB now supports multibit bitfields and enums in target register
472 * New Python-based convenience function $_as_string(val), which returns
473 the textual representation of a value. This function is especially
474 useful to obtain the text label of an enum value.
476 * Intel MPX bound violation handling.
478 Segmentation faults caused by a Intel MPX boundary violation
479 now display the kind of violation (upper or lower), the memory
480 address accessed and the memory bounds, along with the usual
481 signal received and code location.
485 Program received signal SIGSEGV, Segmentation fault
486 Upper bound violation while accessing address 0x7fffffffc3b3
487 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
488 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
490 * Rust language support.
491 GDB now supports debugging programs written in the Rust programming
492 language. See https://www.rust-lang.org/ for more information about
495 * Support for running interpreters on specified input/output devices
497 GDB now supports a new mechanism that allows frontends to provide
498 fully featured GDB console views, as a better alternative to
499 building such views on top of the "-interpreter-exec console"
500 command. See the new "new-ui" command below. With that command,
501 frontends can now start GDB in the traditional command-line mode
502 running in an embedded terminal emulator widget, and create a
503 separate MI interpreter running on a specified i/o device. In this
504 way, GDB handles line editing, history, tab completion, etc. in the
505 console all by itself, and the GUI uses the separate MI interpreter
506 for its own control and synchronization, invisible to the command
509 * The "catch syscall" command catches groups of related syscalls.
511 The "catch syscall" command now supports catching a group of related
512 syscalls using the 'group:' or 'g:' prefix.
517 skip -gfile file-glob-pattern
518 skip -function function
519 skip -rfunction regular-expression
520 A generalized form of the skip command, with new support for
521 glob-style file names and regular expressions for function names.
522 Additionally, a file spec and a function spec may now be combined.
524 maint info line-table REGEXP
525 Display the contents of GDB's internal line table data struture.
528 Run any GDB unit tests that were compiled in.
531 Start a new user interface instance running INTERP as interpreter,
532 using the TTY file for input/output.
536 ** gdb.Breakpoint objects have a new attribute "pending", which
537 indicates whether the breakpoint is pending.
538 ** Three new breakpoint-related events have been added:
539 gdb.breakpoint_created, gdb.breakpoint_modified, and
540 gdb.breakpoint_deleted.
543 Signal ("set") the given MS-Windows event object. This is used in
544 conjunction with the Windows JIT debugging (AeDebug) support, where
545 the OS suspends a crashing process until a debugger can attach to
546 it. Resuming the crashing process, in order to debug it, is done by
549 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
550 was added in GDBserver, including JIT compiling fast tracepoint's
551 conditional expression bytecode into native code.
553 * Support for various remote target protocols and ROM monitors has
556 target m32rsdi Remote M32R debugging over SDI
557 target mips MIPS remote debugging protocol
558 target pmon PMON ROM monitor
559 target ddb NEC's DDB variant of PMON for Vr4300
560 target rockhopper NEC RockHopper variant of PMON
561 target lsi LSI variant of PMO
563 * Support for tracepoints and fast tracepoints on powerpc-linux,
564 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
565 including JIT compiling fast tracepoint's conditional expression
566 bytecode into native code.
568 * MI async record =record-started now includes the method and format used for
569 recording. For example:
571 =record-started,thread-group="i1",method="btrace",format="bts"
573 * MI async record =thread-selected now includes the frame field. For example:
575 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
579 Andes NDS32 nds32*-*-elf
581 *** Changes in GDB 7.11
583 * GDB now supports debugging kernel-based threads on FreeBSD.
585 * Per-inferior thread numbers
587 Thread numbers are now per inferior instead of global. If you're
588 debugging multiple inferiors, GDB displays thread IDs using a
589 qualified INF_NUM.THR_NUM form. For example:
593 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
594 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
595 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
596 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
598 As consequence, thread numbers as visible in the $_thread
599 convenience variable and in Python's InferiorThread.num attribute
600 are no longer unique between inferiors.
602 GDB now maintains a second thread ID per thread, referred to as the
603 global thread ID, which is the new equivalent of thread numbers in
604 previous releases. See also $_gthread below.
606 For backwards compatibility, MI's thread IDs always refer to global
609 * Commands that accept thread IDs now accept the qualified
610 INF_NUM.THR_NUM form as well. For example:
613 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
616 * In commands that accept a list of thread IDs, you can now refer to
617 all threads of an inferior using a star wildcard. GDB accepts
618 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
619 refer to all threads of the current inferior. For example, "info
622 * You can use "info threads -gid" to display the global thread ID of
625 * The new convenience variable $_gthread holds the global number of
628 * The new convenience variable $_inferior holds the number of the
631 * GDB now displays the ID and name of the thread that hit a breakpoint
632 or received a signal, if your program is multi-threaded. For
635 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
636 Thread 1 "main" received signal SIGINT, Interrupt.
638 * Record btrace now supports non-stop mode.
640 * Support for tracepoints on aarch64-linux was added in GDBserver.
642 * The 'record instruction-history' command now indicates speculative execution
643 when using the Intel Processor Trace recording format.
645 * GDB now allows users to specify explicit locations, bypassing
646 the linespec parser. This feature is also available to GDB/MI
649 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
650 GDB now is able to debug both AArch64 applications and ARM applications
653 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
654 including JIT compiling fast tracepoint's conditional expression bytecode
657 * GDB now supports displaced stepping on AArch64 GNU/Linux.
659 * "info threads", "info inferiors", "info display", "info checkpoints"
660 and "maint info program-spaces" now list the corresponding items in
661 ascending ID order, for consistency with all other "info" commands.
663 * In Ada, the overloads selection menu has been enhanced to display the
664 parameter types and the return types for the matching overloaded subprograms.
668 maint set target-non-stop (on|off|auto)
669 maint show target-non-stop
670 Control whether GDB targets always operate in non-stop mode even if
671 "set non-stop" is "off". The default is "auto", meaning non-stop
672 mode is enabled if supported by the target.
674 maint set bfd-sharing
675 maint show bfd-sharing
676 Control the reuse of bfd objects.
680 Control display of debugging info regarding bfd caching.
684 Control display of debugging info regarding FreeBSD threads.
686 set remote multiprocess-extensions-packet
687 show remote multiprocess-extensions-packet
688 Set/show the use of the remote protocol multiprocess extensions.
690 set remote thread-events
691 show remote thread-events
692 Set/show the use of thread create/exit events.
694 set ada print-signatures on|off
695 show ada print-signatures"
696 Control whether parameter types and return types are displayed in overloads
697 selection menus. It is activaled (@code{on}) by default.
701 Controls the maximum size of memory, in bytes, that GDB will
702 allocate for value contents. Prevents incorrect programs from
703 causing GDB to allocate overly large buffers. Default is 64k.
705 * The "disassemble" command accepts a new modifier: /s.
706 It prints mixed source+disassembly like /m with two differences:
707 - disassembled instructions are now printed in program order, and
708 - and source for all relevant files is now printed.
709 The "/m" option is now considered deprecated: its "source-centric"
710 output hasn't proved useful in practice.
712 * The "record instruction-history" command accepts a new modifier: /s.
713 It behaves exactly like /m and prints mixed source+disassembly.
715 * The "set scheduler-locking" command supports a new mode "replay".
716 It behaves like "off" in record mode and like "on" in replay mode.
718 * Support for various ROM monitors has been removed:
720 target dbug dBUG ROM monitor for Motorola ColdFire
721 target picobug Motorola picobug monitor
722 target dink32 DINK32 ROM monitor for PowerPC
723 target m32r Renesas M32R/D ROM monitor
724 target mon2000 mon2000 ROM monitor
725 target ppcbug PPCBUG ROM monitor for PowerPC
727 * Support for reading/writing memory and extracting values on architectures
728 whose memory is addressable in units of any integral multiple of 8 bits.
731 Allows to break when an Ada exception is handled.
736 Indicates that an exec system call was executed.
738 exec-events feature in qSupported
739 The qSupported packet allows GDB to request support for exec
740 events using the new 'gdbfeature' exec-event, and the qSupported
741 response can contain the corresponding 'stubfeature'. Set and
742 show commands can be used to display whether these features are enabled.
745 Equivalent to interrupting with the ^C character, but works in
748 thread created stop reason (T05 create:...)
749 Indicates that the thread was just created and is stopped at entry.
751 thread exit stop reply (w exitcode;tid)
752 Indicates that the thread has terminated.
755 Enables/disables thread create and exit event reporting. For
756 example, this is used in non-stop mode when GDB stops a set of
757 threads and synchronously waits for the their corresponding stop
758 replies. Without exit events, if one of the threads exits, GDB
759 would hang forever not knowing that it should no longer expect a
760 stop for that same thread.
763 Indicates that there are no resumed threads left in the target (all
764 threads are stopped). The remote stub reports support for this stop
765 reply to GDB's qSupported query.
768 Enables/disables catching syscalls from the inferior process.
769 The remote stub reports support for this packet to GDB's qSupported query.
771 syscall_entry stop reason
772 Indicates that a syscall was just called.
774 syscall_return stop reason
775 Indicates that a syscall just returned.
777 * Extended-remote exec events
779 ** GDB now has support for exec events on extended-remote Linux targets.
780 For such targets with Linux kernels 2.5.46 and later, this enables
781 follow-exec-mode and exec catchpoints.
783 set remote exec-event-feature-packet
784 show remote exec-event-feature-packet
785 Set/show the use of the remote exec event feature.
787 * Thread names in remote protocol
789 The reply to qXfer:threads:read may now include a name attribute for each
792 * Target remote mode fork and exec events
794 ** GDB now has support for fork and exec events on target remote mode
795 Linux targets. For such targets with Linux kernels 2.5.46 and later,
796 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
797 fork and exec catchpoints.
799 * Remote syscall events
801 ** GDB now has support for catch syscall on remote Linux targets,
802 currently enabled on x86/x86_64 architectures.
804 set remote catch-syscall-packet
805 show remote catch-syscall-packet
806 Set/show the use of the remote catch syscall feature.
810 ** The -var-set-format command now accepts the zero-hexadecimal
811 format. It outputs data in hexadecimal format with zero-padding on the
816 ** gdb.InferiorThread objects have a new attribute "global_num",
817 which refers to the thread's global thread ID. The existing
818 "num" attribute now refers to the thread's per-inferior number.
819 See "Per-inferior thread numbers" above.
820 ** gdb.InferiorThread objects have a new attribute "inferior", which
821 is the Inferior object the thread belongs to.
823 *** Changes in GDB 7.10
825 * Support for process record-replay and reverse debugging on aarch64*-linux*
826 targets has been added. GDB now supports recording of A64 instruction set
827 including advance SIMD instructions.
829 * Support for Sun's version of the "stabs" debug file format has been removed.
831 * GDB now honors the content of the file /proc/PID/coredump_filter
832 (PID is the process ID) on GNU/Linux systems. This file can be used
833 to specify the types of memory mappings that will be included in a
834 corefile. For more information, please refer to the manual page of
835 "core(5)". GDB also has a new command: "set use-coredump-filter
836 on|off". It allows to set whether GDB will read the content of the
837 /proc/PID/coredump_filter file when generating a corefile.
839 * The "info os" command on GNU/Linux can now display information on
841 "info os cpus" Listing of all cpus/cores on the system
843 * GDB has two new commands: "set serial parity odd|even|none" and
844 "show serial parity". These allows to set or show parity for the
847 * The "info source" command now displays the producer string if it was
848 present in the debug info. This typically includes the compiler version
849 and may include things like its command line arguments.
851 * The "info dll", an alias of the "info sharedlibrary" command,
852 is now available on all platforms.
854 * Directory names supplied to the "set sysroot" commands may be
855 prefixed with "target:" to tell GDB to access shared libraries from
856 the target system, be it local or remote. This replaces the prefix
857 "remote:". The default sysroot has been changed from "" to
858 "target:". "remote:" is automatically converted to "target:" for
859 backward compatibility.
861 * The system root specified by "set sysroot" will be prepended to the
862 filename of the main executable (if reported to GDB as absolute by
863 the operating system) when starting processes remotely, and when
864 attaching to already-running local or remote processes.
866 * GDB now supports automatic location and retrieval of executable
867 files from remote targets. Remote debugging can now be initiated
868 using only a "target remote" or "target extended-remote" command
869 (no "set sysroot" or "file" commands are required). See "New remote
872 * The "dump" command now supports verilog hex format.
874 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
876 * On GNU/Linux, GDB and gdbserver are now able to access executable
877 and shared library files without a "set sysroot" command when
878 attaching to processes running in different mount namespaces from
879 the debugger. This makes it possible to attach to processes in
880 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
881 See "New remote packets" below.
883 * The "tui reg" command now provides completion for all of the
884 available register groups, including target specific groups.
886 * The HISTSIZE environment variable is no longer read when determining
887 the size of GDB's command history. GDB now instead reads the dedicated
888 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
889 disables truncation of command history. Non-numeric values of GDBHISTSIZE
894 ** Memory ports can now be unbuffered.
898 ** gdb.Objfile objects have a new attribute "username",
899 which is the name of the objfile as specified by the user,
900 without, for example, resolving symlinks.
901 ** You can now write frame unwinders in Python.
902 ** gdb.Type objects have a new method "optimized_out",
903 returning optimized out gdb.Value instance of this type.
904 ** gdb.Value objects have new methods "reference_value" and
905 "const_value" which return a reference to the value and a
906 "const" version of the value respectively.
910 maint print symbol-cache
911 Print the contents of the symbol cache.
913 maint print symbol-cache-statistics
914 Print statistics of symbol cache usage.
916 maint flush-symbol-cache
917 Flush the contents of the symbol cache.
921 Start branch trace recording using Branch Trace Store (BTS) format.
924 Evaluate expression by using the compiler and print result.
928 Explicit commands for enabling and disabling tui mode.
931 set mpx bound on i386 and amd64
932 Support for bound table investigation on Intel MPX enabled applications.
936 Start branch trace recording using Intel Processor Trace format.
939 Print information about branch tracing internals.
941 maint btrace packet-history
942 Print the raw branch tracing data.
944 maint btrace clear-packet-history
945 Discard the stored raw branch tracing data.
948 Discard all branch tracing data. It will be fetched and processed
949 anew by the next "record" command.
954 Renamed from "set debug dwarf2-die".
956 Renamed from "show debug dwarf2-die".
959 Renamed from "set debug dwarf2-read".
960 show debug dwarf-read
961 Renamed from "show debug dwarf2-read".
963 maint set dwarf always-disassemble
964 Renamed from "maint set dwarf2 always-disassemble".
965 maint show dwarf always-disassemble
966 Renamed from "maint show dwarf2 always-disassemble".
968 maint set dwarf max-cache-age
969 Renamed from "maint set dwarf2 max-cache-age".
970 maint show dwarf max-cache-age
971 Renamed from "maint show dwarf2 max-cache-age".
974 show debug dwarf-line
975 Control display of debugging info regarding DWARF line processing.
979 Set the maximum number of candidates to be considered during
980 completion. The default value is 200. This limit allows GDB
981 to avoid generating large completion lists, the computation of
982 which can cause the debugger to become temporarily unresponsive.
984 set history remove-duplicates
985 show history remove-duplicates
986 Control the removal of duplicate history entries.
988 maint set symbol-cache-size
989 maint show symbol-cache-size
990 Control the size of the symbol cache.
992 set|show record btrace bts buffer-size
993 Set and show the size of the ring buffer used for branch tracing in
995 The obtained size may differ from the requested size. Use "info
996 record" to see the obtained buffer size.
998 set debug linux-namespaces
999 show debug linux-namespaces
1000 Control display of debugging info regarding Linux namespaces.
1002 set|show record btrace pt buffer-size
1003 Set and show the size of the ring buffer used for branch tracing in
1004 Intel Processor Trace format.
1005 The obtained size may differ from the requested size. Use "info
1006 record" to see the obtained buffer size.
1008 maint set|show btrace pt skip-pad
1009 Set and show whether PAD packets are skipped when computing the
1012 * The command 'thread apply all' can now support new option '-ascending'
1013 to call its specified command for all threads in ascending order.
1015 * Python/Guile scripting
1017 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1018 special section named `.debug_gdb_scripts'.
1020 * New remote packets
1022 qXfer:btrace-conf:read
1023 Return the branch trace configuration for the current thread.
1025 Qbtrace-conf:bts:size
1026 Set the requested ring buffer size for branch tracing in BTS format.
1029 Enable Intel Procesor Trace-based branch tracing for the current
1030 process. The remote stub reports support for this packet to GDB's
1033 Qbtrace-conf:pt:size
1034 Set the requested ring buffer size for branch tracing in Intel Processor
1038 Indicates a memory breakpoint instruction was executed, irrespective
1039 of whether it was GDB that planted the breakpoint or the breakpoint
1040 is hardcoded in the program. This is required for correct non-stop
1044 Indicates the target stopped for a hardware breakpoint. This is
1045 required for correct non-stop mode operation.
1048 Return information about files on the remote system.
1050 qXfer:exec-file:read
1051 Return the full absolute name of the file that was executed to
1052 create a process running on the remote system.
1055 Select the filesystem on which vFile: operations with filename
1056 arguments will operate. This is required for GDB to be able to
1057 access files on remote targets where the remote stub does not
1058 share a common filesystem with the inferior(s).
1061 Indicates that a fork system call was executed.
1064 Indicates that a vfork system call was executed.
1066 vforkdone stop reason
1067 Indicates that a vfork child of the specified process has executed
1068 an exec or exit, allowing the vfork parent to resume execution.
1070 fork-events and vfork-events features in qSupported
1071 The qSupported packet allows GDB to request support for fork and
1072 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1073 and the qSupported response can contain the corresponding
1074 'stubfeatures'. Set and show commands can be used to display
1075 whether these features are enabled.
1077 * Extended-remote fork events
1079 ** GDB now has support for fork events on extended-remote Linux
1080 targets. For targets with Linux kernels 2.5.60 and later, this
1081 enables follow-fork-mode and detach-on-fork for both fork and
1082 vfork, as well as fork and vfork catchpoints.
1084 * The info record command now shows the recording format and the
1085 branch tracing configuration for the current thread when using
1086 the btrace record target.
1087 For the BTS format, it shows the ring buffer size.
1089 * GDB now has support for DTrace USDT (Userland Static Defined
1090 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1092 * GDB now supports access to vector registers on S/390 GNU/Linux
1095 * Removed command line options
1097 -xdb HP-UX XDB compatibility mode.
1099 * Removed targets and native configurations
1101 HP/PA running HP-UX hppa*-*-hpux*
1102 Itanium running HP-UX ia64-*-hpux*
1104 * New configure options
1107 This configure option allows the user to build GDB with support for
1108 Intel Processor Trace (default: auto). This requires libipt.
1110 --with-libipt-prefix=PATH
1111 Specify the path to the version of libipt that GDB should use.
1112 $PATH/include should contain the intel-pt.h header and
1113 $PATH/lib should contain the libipt.so library.
1115 *** Changes in GDB 7.9.1
1119 ** Xmethods can now specify a result type.
1121 *** Changes in GDB 7.9
1123 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1127 ** You can now access frame registers from Python scripts.
1128 ** New attribute 'producer' for gdb.Symtab objects.
1129 ** gdb.Objfile objects have a new attribute "progspace",
1130 which is the gdb.Progspace object of the containing program space.
1131 ** gdb.Objfile objects have a new attribute "owner".
1132 ** gdb.Objfile objects have a new attribute "build_id",
1133 which is the build ID generated when the file was built.
1134 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1135 ** A new event "gdb.clear_objfiles" has been added, triggered when
1136 selecting a new file to debug.
1137 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1138 ** New function gdb.lookup_objfile.
1140 New events which are triggered when GDB modifies the state of the
1143 ** gdb.events.inferior_call_pre: Function call is about to be made.
1144 ** gdb.events.inferior_call_post: Function call has just been made.
1145 ** gdb.events.memory_changed: A memory location has been altered.
1146 ** gdb.events.register_changed: A register has been altered.
1148 * New Python-based convenience functions:
1150 ** $_caller_is(name [, number_of_frames])
1151 ** $_caller_matches(regexp [, number_of_frames])
1152 ** $_any_caller_is(name [, number_of_frames])
1153 ** $_any_caller_matches(regexp [, number_of_frames])
1155 * GDB now supports the compilation and injection of source code into
1156 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1157 to compile the source code to object code, and if successful, inject
1158 and execute that code within the current context of the inferior.
1159 Currently the C language is supported. The commands used to
1160 interface with this new feature are:
1162 compile code [-raw|-r] [--] [source code]
1163 compile file [-raw|-r] filename
1167 demangle [-l language] [--] name
1168 Demangle "name" in the specified language, or the current language
1169 if elided. This command is renamed from the "maint demangle" command.
1170 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1171 as "maint demangler-warning".
1173 queue-signal signal-name-or-number
1174 Queue a signal to be delivered to the thread when it is resumed.
1176 add-auto-load-scripts-directory directory
1177 Add entries to the list of directories from which to load auto-loaded
1180 maint print user-registers
1181 List all currently available "user" registers.
1183 compile code [-r|-raw] [--] [source code]
1184 Compile, inject, and execute in the inferior the executable object
1185 code produced by compiling the provided source code.
1187 compile file [-r|-raw] filename
1188 Compile and inject into the inferior the executable object code
1189 produced by compiling the source code stored in the filename
1192 * On resume, GDB now always passes the signal the program had stopped
1193 for to the thread the signal was sent to, even if the user changed
1194 threads before resuming. Previously GDB would often (but not
1195 always) deliver the signal to the thread that happens to be current
1198 * Conversely, the "signal" command now consistently delivers the
1199 requested signal to the current thread. GDB now asks for
1200 confirmation if the program had stopped for a signal and the user
1201 switched threads meanwhile.
1203 * "breakpoint always-inserted" modes "off" and "auto" merged.
1205 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1206 won't remove breakpoints from the target until all threads stop,
1207 even in non-stop mode. The "auto" mode has been removed, and "off"
1208 is now the default mode.
1212 set debug symbol-lookup
1213 show debug symbol-lookup
1214 Control display of debugging info regarding symbol lookup.
1218 ** The -list-thread-groups command outputs an exit-code field for
1219 inferiors that have exited.
1223 MIPS SDE mips*-sde*-elf*
1227 Support for these obsolete configurations has been removed.
1229 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1230 SGI Irix-5.x mips-*-irix5*
1231 SGI Irix-6.x mips-*-irix6*
1232 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1233 VAX running Ultrix vax-*-ultrix*
1235 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1236 and "assf"), have been removed. Use the "sharedlibrary" command, or
1237 its alias "share", instead.
1239 *** Changes in GDB 7.8
1241 * New command line options
1244 This is an alias for the --data-directory option.
1246 * GDB supports printing and modifying of variable length automatic arrays
1247 as specified in ISO C99.
1249 * The ARM simulator now supports instruction level tracing
1250 with or without disassembly.
1254 GDB now has support for scripting using Guile. Whether this is
1255 available is determined at configure time.
1256 Guile version 2.0 or greater is required.
1257 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1259 * New commands (for set/show, see "New options" below)
1263 Invoke CODE by passing it to the Guile interpreter.
1267 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1269 info auto-load guile-scripts [regexp]
1270 Print the list of automatically loaded Guile scripts.
1272 * The source command is now capable of sourcing Guile scripts.
1273 This feature is dependent on the debugger being built with Guile support.
1277 set print symbol-loading (off|brief|full)
1278 show print symbol-loading
1279 Control whether to print informational messages when loading symbol
1280 information for a file. The default is "full", but when debugging
1281 programs with large numbers of shared libraries the amount of output
1282 becomes less useful.
1284 set guile print-stack (none|message|full)
1285 show guile print-stack
1286 Show a stack trace when an error is encountered in a Guile script.
1288 set auto-load guile-scripts (on|off)
1289 show auto-load guile-scripts
1290 Control auto-loading of Guile script files.
1292 maint ada set ignore-descriptive-types (on|off)
1293 maint ada show ignore-descriptive-types
1294 Control whether the debugger should ignore descriptive types in Ada
1295 programs. The default is not to ignore the descriptive types. See
1296 the user manual for more details on descriptive types and the intended
1297 usage of this option.
1299 set auto-connect-native-target
1301 Control whether GDB is allowed to automatically connect to the
1302 native target for the run, attach, etc. commands when not connected
1303 to any target yet. See also "target native" below.
1305 set record btrace replay-memory-access (read-only|read-write)
1306 show record btrace replay-memory-access
1307 Control what memory accesses are allowed during replay.
1309 maint set target-async (on|off)
1310 maint show target-async
1311 This controls whether GDB targets operate in synchronous or
1312 asynchronous mode. Normally the default is asynchronous, if it is
1313 available; but this can be changed to more easily debug problems
1314 occurring only in synchronous mode.
1316 set mi-async (on|off)
1318 Control whether MI asynchronous mode is preferred. This supersedes
1319 "set target-async" of previous GDB versions.
1321 * "set target-async" is deprecated as a CLI option and is now an alias
1322 for "set mi-async" (only puts MI into async mode).
1324 * Background execution commands (e.g., "c&", "s&", etc.) are now
1325 possible ``out of the box'' if the target supports them. Previously
1326 the user would need to explicitly enable the possibility with the
1327 "set target-async on" command.
1329 * New features in the GDB remote stub, GDBserver
1331 ** New option --debug-format=option1[,option2,...] allows one to add
1332 additional text to each output. At present only timestamps
1333 are supported: --debug-format=timestamps.
1334 Timestamps can also be turned on with the
1335 "monitor set debug-format timestamps" command from GDB.
1337 * The 'record instruction-history' command now starts counting instructions
1338 at one. This also affects the instruction ranges reported by the
1339 'record function-call-history' command when given the /i modifier.
1341 * The command 'record function-call-history' supports a new modifier '/c' to
1342 indent the function names based on their call stack depth.
1343 The fields for the '/i' and '/l' modifier have been reordered.
1344 The source line range is now prefixed with 'at'.
1345 The instruction range is now prefixed with 'inst'.
1346 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1347 "record instruction-history" and "list" commands.
1349 * The ranges given as arguments to the 'record function-call-history' and
1350 'record instruction-history' commands are now inclusive.
1352 * The btrace record target now supports the 'record goto' command.
1353 For locations inside the execution trace, the back trace is computed
1354 based on the information stored in the execution trace.
1356 * The btrace record target supports limited reverse execution and replay.
1357 The target does not record data and therefore does not allow reading
1358 memory or registers.
1360 * The "catch syscall" command now works on s390*-linux* targets.
1362 * The "compare-sections" command is no longer specific to target
1363 remote. It now works with all targets.
1365 * All native targets are now consistently called "native".
1366 Consequently, the "target child", "target GNU", "target djgpp",
1367 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1368 commands have been replaced with "target native". The QNX/NTO port
1369 leaves the "procfs" target in place and adds a "native" target for
1370 consistency with other ports. The impact on users should be minimal
1371 as these commands previously either throwed an error, or were
1372 no-ops. The target's name is visible in the output of the following
1373 commands: "help target", "info target", "info files", "maint print
1376 * The "target native" command now connects to the native target. This
1377 can be used to launch native programs even when "set
1378 auto-connect-native-target" is set to off.
1380 * GDB now supports access to Intel MPX registers on GNU/Linux.
1382 * Support for Intel AVX-512 registers on GNU/Linux.
1383 Support displaying and modifying Intel AVX-512 registers
1384 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1386 * New remote packets
1388 qXfer:btrace:read's annex
1389 The qXfer:btrace:read packet supports a new annex 'delta' to read
1390 branch trace incrementally.
1394 ** Valid Python operations on gdb.Value objects representing
1395 structs/classes invoke the corresponding overloaded operators if
1397 ** New `Xmethods' feature in the Python API. Xmethods are
1398 additional methods or replacements for existing methods of a C++
1399 class. This feature is useful for those cases where a method
1400 defined in C++ source code could be inlined or optimized out by
1401 the compiler, making it unavailable to GDB.
1404 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1406 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1407 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1408 its alias "share", instead.
1410 * The commands "set remotebaud" and "show remotebaud" are no longer
1411 supported. Use "set serial baud" and "show serial baud" (respectively)
1416 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1417 target-async". The latter is left as a deprecated alias of the
1418 former for backward compatibility. If the target supports it,
1419 CLI background execution commands are now always possible by
1420 default, independently of whether the frontend stated a
1421 preference for asynchronous execution with "-gdb-set mi-async".
1422 Previously "-gdb-set target-async off" affected both MI execution
1423 commands and CLI execution commands.
1425 *** Changes in GDB 7.7
1427 * Improved support for process record-replay and reverse debugging on
1428 arm*-linux* targets. Support for thumb32 and syscall instruction
1429 recording has been added.
1431 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1433 * GDB now supports Fission DWP file format version 2.
1434 http://gcc.gnu.org/wiki/DebugFission
1436 * New convenience function "$_isvoid", to check whether an expression
1437 is void. A void expression is an expression where the type of the
1438 result is "void". For example, some convenience variables may be
1439 "void" when evaluated (e.g., "$_exitcode" before the execution of
1440 the program being debugged; or an undefined convenience variable).
1441 Another example, when calling a function whose return type is
1444 * The "maintenance print objfiles" command now takes an optional regexp.
1446 * The "catch syscall" command now works on arm*-linux* targets.
1448 * GDB now consistently shows "<not saved>" when printing values of
1449 registers the debug info indicates have not been saved in the frame
1450 and there's nowhere to retrieve them from
1451 (callee-saved/call-clobbered registers):
1456 (gdb) info registers rax
1459 Before, the former would print "<optimized out>", and the latter
1460 "*value not available*".
1462 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1467 ** Frame filters and frame decorators have been added.
1468 ** Temporary breakpoints are now supported.
1469 ** Line tables representation has been added.
1470 ** New attribute 'parent_type' for gdb.Field objects.
1471 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1472 ** New attribute 'name' for gdb.Type objects.
1476 Nios II ELF nios2*-*-elf
1477 Nios II GNU/Linux nios2*-*-linux
1478 Texas Instruments MSP430 msp430*-*-elf
1480 * Removed native configurations
1482 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1483 been removed. ELF variants of these configurations are kept supported.
1485 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1486 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1487 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1488 i[34567]86-*-openbsd3.[0-3]
1489 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1490 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1491 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1495 Like "catch throw", but catches a re-thrown exception.
1496 maint check-psymtabs
1497 Renamed from old "maint check-symtabs".
1499 Perform consistency checks on symtabs.
1500 maint expand-symtabs
1501 Expand symtabs matching an optional regexp.
1504 Display the details of GDB configure-time options.
1506 maint set|show per-command
1507 maint set|show per-command space
1508 maint set|show per-command time
1509 maint set|show per-command symtab
1510 Enable display of per-command gdb resource usage.
1512 remove-symbol-file FILENAME
1513 remove-symbol-file -a ADDRESS
1514 Remove a symbol file added via add-symbol-file. The file to remove
1515 can be identified by its filename or by an address that lies within
1516 the boundaries of this symbol file in memory.
1519 info exceptions REGEXP
1520 Display the list of Ada exceptions defined in the program being
1521 debugged. If provided, only the exceptions whose names match REGEXP
1526 set debug symfile off|on
1528 Control display of debugging info regarding reading symbol files and
1529 symbol tables within those files
1531 set print raw frame-arguments
1532 show print raw frame-arguments
1533 Set/show whether to print frame arguments in raw mode,
1534 disregarding any defined pretty-printers.
1536 set remote trace-status-packet
1537 show remote trace-status-packet
1538 Set/show the use of remote protocol qTStatus packet.
1542 Control display of debugging messages related to Nios II targets.
1546 Control whether target-assisted range stepping is enabled.
1548 set startup-with-shell
1549 show startup-with-shell
1550 Specifies whether Unix child processes are started via a shell or
1555 Use the target memory cache for accesses to the code segment. This
1556 improves performance of remote debugging (particularly disassembly).
1558 * You can now use a literal value 'unlimited' for options that
1559 interpret 0 or -1 as meaning "unlimited". E.g., "set
1560 trace-buffer-size unlimited" is now an alias for "set
1561 trace-buffer-size -1" and "set height unlimited" is now an alias for
1564 * The "set debug symtab-create" debugging option of GDB has been changed to
1565 accept a verbosity level. 0 means "off", 1 provides basic debugging
1566 output, and values of 2 or greater provides more verbose output.
1568 * New command-line options
1570 Display the details of GDB configure-time options.
1572 * The command 'tsave' can now support new option '-ctf' to save trace
1573 buffer in Common Trace Format.
1575 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1578 * GDB now implements the the C++ 'typeid' operator.
1580 * The new convenience variable $_exception holds the exception being
1581 thrown or caught at an exception-related catchpoint.
1583 * The exception-related catchpoints, like "catch throw", now accept a
1584 regular expression which can be used to filter exceptions by type.
1586 * The new convenience variable $_exitsignal is automatically set to
1587 the terminating signal number when the program being debugged dies
1588 due to an uncaught signal.
1592 ** All MI commands now accept an optional "--language" option.
1593 Support for this feature can be verified by using the "-list-features"
1594 command, which should contain "language-option".
1596 ** The new command -info-gdb-mi-command allows the user to determine
1597 whether a GDB/MI command is supported or not.
1599 ** The "^error" result record returned when trying to execute an undefined
1600 GDB/MI command now provides a variable named "code" whose content is the
1601 "undefined-command" error code. Support for this feature can be verified
1602 by using the "-list-features" command, which should contain
1603 "undefined-command-error-code".
1605 ** The -trace-save MI command can optionally save trace buffer in Common
1608 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1610 ** The command -data-list-register-values now accepts an optional
1611 "--skip-unavailable" option. When used, only the available registers
1614 ** The new command -trace-frame-collected dumps collected variables,
1615 computed expressions, tvars, memory and registers in a traceframe.
1617 ** The commands -stack-list-locals, -stack-list-arguments and
1618 -stack-list-variables now accept an option "--skip-unavailable".
1619 When used, only the available locals or arguments are displayed.
1621 ** The -exec-run command now accepts an optional "--start" option.
1622 When used, the command follows the same semantics as the "start"
1623 command, stopping the program's execution at the start of its
1624 main subprogram. Support for this feature can be verified using
1625 the "-list-features" command, which should contain
1626 "exec-run-start-option".
1628 ** The new commands -catch-assert and -catch-exceptions insert
1629 catchpoints stopping the program when Ada exceptions are raised.
1631 ** The new command -info-ada-exceptions provides the equivalent of
1632 the new "info exceptions" command.
1634 * New system-wide configuration scripts
1635 A GDB installation now provides scripts suitable for use as system-wide
1636 configuration scripts for the following systems:
1640 * GDB now supports target-assigned range stepping with remote targets.
1641 This improves the performance of stepping source lines by reducing
1642 the number of control packets from/to GDB. See "New remote packets"
1645 * GDB now understands the element 'tvar' in the XML traceframe info.
1646 It has the id of the collected trace state variables.
1648 * On S/390 targets that provide the transactional-execution feature,
1649 the program interruption transaction diagnostic block (TDB) is now
1650 represented as a number of additional "registers" in GDB.
1652 * New remote packets
1656 The vCont packet supports a new 'r' action, that tells the remote
1657 stub to step through an address range itself, without GDB
1658 involvemement at each single-step.
1660 qXfer:libraries-svr4:read's annex
1661 The previously unused annex of the qXfer:libraries-svr4:read packet
1662 is now used to support passing an argument list. The remote stub
1663 reports support for this argument list to GDB's qSupported query.
1664 The defined arguments are "start" and "prev", used to reduce work
1665 necessary for library list updating, resulting in significant
1668 * New features in the GDB remote stub, GDBserver
1670 ** GDBserver now supports target-assisted range stepping. Currently
1671 enabled on x86/x86_64 GNU/Linux targets.
1673 ** GDBserver now adds element 'tvar' in the XML in the reply to
1674 'qXfer:traceframe-info:read'. It has the id of the collected
1675 trace state variables.
1677 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1680 * New 'z' formatter for printing and examining memory, this displays the
1681 value as hexadecimal zero padded on the left to the size of the type.
1683 * GDB can now use Windows x64 unwinding data.
1685 * The "set remotebaud" command has been replaced by "set serial baud".
1686 Similarly, "show remotebaud" has been replaced by "show serial baud".
1687 The "set remotebaud" and "show remotebaud" commands are still available
1688 to provide backward compatibility with older versions of GDB.
1690 *** Changes in GDB 7.6
1692 * Target record has been renamed to record-full.
1693 Record/replay is now enabled with the "record full" command.
1694 This also affects settings that are associated with full record/replay
1695 that have been moved from "set/show record" to "set/show record full":
1697 set|show record full insn-number-max
1698 set|show record full stop-at-limit
1699 set|show record full memory-query
1701 * A new record target "record-btrace" has been added. The new target
1702 uses hardware support to record the control-flow of a process. It
1703 does not support replaying the execution, but it implements the
1704 below new commands for investigating the recorded execution log.
1705 This new recording method can be enabled using:
1709 The "record-btrace" target is only available on Intel Atom processors
1710 and requires a Linux kernel 2.6.32 or later.
1712 * Two new commands have been added for record/replay to give information
1713 about the recorded execution without having to replay the execution.
1714 The commands are only supported by "record btrace".
1716 record instruction-history prints the execution history at
1717 instruction granularity
1719 record function-call-history prints the execution history at
1720 function granularity
1722 * New native configurations
1724 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1725 FreeBSD/powerpc powerpc*-*-freebsd
1726 x86_64/Cygwin x86_64-*-cygwin*
1727 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1731 ARM AArch64 aarch64*-*-elf
1732 ARM AArch64 GNU/Linux aarch64*-*-linux
1733 Lynx 178 PowerPC powerpc-*-lynx*178
1734 x86_64/Cygwin x86_64-*-cygwin*
1735 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1737 * If the configured location of system.gdbinit file (as given by the
1738 --with-system-gdbinit option at configure time) is in the
1739 data-directory (as specified by --with-gdb-datadir at configure
1740 time) or in one of its subdirectories, then GDB will look for the
1741 system-wide init file in the directory specified by the
1742 --data-directory command-line option.
1744 * New command line options:
1746 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1747 other initialization files, unlike -nx which disables all of them.
1749 * Removed command line options
1751 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1754 * The 'ptype' and 'whatis' commands now accept an argument to control
1757 * 'info proc' now works on some core files.
1761 ** Vectors can be created with gdb.Type.vector.
1763 ** Python's atexit.register now works in GDB.
1765 ** Types can be pretty-printed via a Python API.
1767 ** Python 3 is now supported (in addition to Python 2.4 or later)
1769 ** New class gdb.Architecture exposes GDB's internal representation
1770 of architecture in the Python API.
1772 ** New method Frame.architecture returns the gdb.Architecture object
1773 corresponding to the frame's architecture.
1775 * New Python-based convenience functions:
1777 ** $_memeq(buf1, buf2, length)
1778 ** $_streq(str1, str2)
1780 ** $_regex(str, regex)
1782 * The 'cd' command now defaults to using '~' (the home directory) if not
1785 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1786 default for GCC since November 2000.
1788 * The command 'forward-search' can now be abbreviated as 'fo'.
1790 * The command 'info tracepoints' can now display 'installed on target'
1791 or 'not installed on target' for each non-pending location of tracepoint.
1793 * New configure options
1795 --enable-libmcheck/--disable-libmcheck
1796 By default, development versions are built with -lmcheck on hosts
1797 that support it, in order to help track memory corruption issues.
1798 Release versions, on the other hand, are built without -lmcheck
1799 by default. The --enable-libmcheck/--disable-libmcheck configure
1800 options allow the user to override that default.
1801 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1802 This configure option allows the user to build GDB with
1803 libbabeltrace using which GDB can read Common Trace Format data.
1805 * New commands (for set/show, see "New options" below)
1808 Catch signals. This is similar to "handle", but allows commands and
1809 conditions to be attached.
1812 List the BFDs known to GDB.
1814 python-interactive [command]
1816 Start a Python interactive prompt, or evaluate the optional command
1817 and print the result of expressions.
1820 "py" is a new alias for "python".
1822 enable type-printer [name]...
1823 disable type-printer [name]...
1824 Enable or disable type printers.
1828 ** For the Renesas Super-H architecture, the "regs" command has been removed
1829 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1834 set print type methods (on|off)
1835 show print type methods
1836 Control whether method declarations are displayed by "ptype".
1837 The default is to show them.
1839 set print type typedefs (on|off)
1840 show print type typedefs
1841 Control whether typedef definitions are displayed by "ptype".
1842 The default is to show them.
1844 set filename-display basename|relative|absolute
1845 show filename-display
1846 Control the way in which filenames is displayed.
1847 The default is "relative", which preserves previous behavior.
1849 set trace-buffer-size
1850 show trace-buffer-size
1851 Request target to change the size of trace buffer.
1853 set remote trace-buffer-size-packet auto|on|off
1854 show remote trace-buffer-size-packet
1855 Control the use of the remote protocol `QTBuffer:size' packet.
1859 Control display of debugging messages related to ARM AArch64.
1862 set debug coff-pe-read
1863 show debug coff-pe-read
1864 Control display of debugging messages related to reading of COFF/PE
1869 Control display of debugging messages related to Mach-O symbols
1872 set debug notification
1873 show debug notification
1874 Control display of debugging info for async remote notification.
1878 ** Command parameter changes are now notified using new async record
1879 "=cmd-param-changed".
1880 ** Trace frame changes caused by command "tfind" are now notified using
1881 new async record "=traceframe-changed".
1882 ** The creation, deletion and modification of trace state variables
1883 are now notified using new async records "=tsv-created",
1884 "=tsv-deleted" and "=tsv-modified".
1885 ** The start and stop of process record are now notified using new
1886 async record "=record-started" and "=record-stopped".
1887 ** Memory changes are now notified using new async record
1889 ** The data-disassemble command response will include a "fullname" field
1890 containing the absolute file name when source has been requested.
1891 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1892 command, to allow pattern filling of memory areas.
1893 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1894 library load/unload events.
1895 ** The response to breakpoint commands and breakpoint async records
1896 includes an "installed" field containing a boolean state about each
1897 non-pending tracepoint location is whether installed on target or not.
1898 ** Output of the "-trace-status" command includes a "trace-file" field
1899 containing the name of the trace file being examined. This field is
1900 optional, and only present when examining a trace file.
1901 ** The "fullname" field is now always present along with the "file" field,
1902 even if the file cannot be found by GDB.
1904 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1905 You must have the LZMA library available when configuring GDB for this
1906 feature to be enabled. For more information, see:
1907 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1909 * New remote packets
1912 Set the size of trace buffer. The remote stub reports support for this
1913 packet to gdb's qSupported query.
1916 Enable Branch Trace Store (BTS)-based branch tracing for the current
1917 thread. The remote stub reports support for this packet to gdb's
1921 Disable branch tracing for the current thread. The remote stub reports
1922 support for this packet to gdb's qSupported query.
1925 Read the traced branches for the current thread. The remote stub
1926 reports support for this packet to gdb's qSupported query.
1928 *** Changes in GDB 7.5
1930 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1931 for more x32 ABI info.
1933 * GDB now supports access to MIPS DSP registers on Linux targets.
1935 * GDB now supports debugging microMIPS binaries.
1937 * The "info os" command on GNU/Linux can now display information on
1938 several new classes of objects managed by the operating system:
1939 "info os procgroups" lists process groups
1940 "info os files" lists file descriptors
1941 "info os sockets" lists internet-domain sockets
1942 "info os shm" lists shared-memory regions
1943 "info os semaphores" lists semaphores
1944 "info os msg" lists message queues
1945 "info os modules" lists loaded kernel modules
1947 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1948 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1949 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1950 options and inspect the probe arguments using the new $_probe_arg family
1951 of convenience variables. You can obtain more information about SystemTap
1952 in <http://sourceware.org/systemtap/>.
1954 * GDB now supports reversible debugging on ARM, it allows you to
1955 debug basic ARM and THUMB instructions, and provides
1956 record/replay support.
1958 * The option "symbol-reloading" has been deleted as it is no longer used.
1962 ** GDB commands implemented in Python can now be put in command class
1965 ** The "maint set python print-stack on|off" is now deleted.
1967 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1968 apply "flag enum"-style pretty-printing to any enum.
1970 ** gdb.lookup_symbol can now work when there is no current frame.
1972 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1973 the source at which the symbol was defined.
1975 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1976 method 'value'. The former indicates whether the symbol needs a
1977 frame in order to compute its value, and the latter computes the
1980 ** A new method 'referenced_value' on gdb.Value objects which can
1981 dereference pointer as well as C++ reference values.
1983 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1984 which return the global and static blocks (as gdb.Block objects),
1985 of the underlying symbol table, respectively.
1987 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1988 object associated with a PC value.
1990 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1991 of the address range occupied by code for the current source line.
1993 * Go language support.
1994 GDB now supports debugging programs written in the Go programming
1997 * GDBserver now supports stdio connections.
1998 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2000 * The binary "gdbtui" can no longer be built or installed.
2001 Use "gdb -tui" instead.
2003 * GDB will now print "flag" enums specially. A flag enum is one where
2004 all the enumerator values have no bits in common when pairwise
2005 "and"ed. When printing a value whose type is a flag enum, GDB will
2006 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2007 (gdb) print (enum E) 3
2010 * The filename part of a linespec will now match trailing components
2011 of a source file name. For example, "break gcc/expr.c:1000" will
2012 now set a breakpoint in build/gcc/expr.c, but not
2013 build/libcpp/expr.c.
2015 * The "info proc" and "generate-core-file" commands will now also
2016 work on remote targets connected to GDBserver on Linux.
2018 * The command "info catch" has been removed. It has been disabled
2019 since December 2007.
2021 * The "catch exception" and "catch assert" commands now accept
2022 a condition at the end of the command, much like the "break"
2023 command does. For instance:
2025 (gdb) catch exception Constraint_Error if Barrier = True
2027 Previously, it was possible to add a condition to such catchpoints,
2028 but it had to be done as a second step, after the catchpoint had been
2029 created, using the "condition" command.
2031 * The "info static-tracepoint-marker" command will now also work on
2032 native Linux targets with in-process agent.
2034 * GDB can now set breakpoints on inlined functions.
2036 * The .gdb_index section has been updated to include symbols for
2037 inlined functions. GDB will ignore older .gdb_index sections by
2038 default, which could cause symbol files to be loaded more slowly
2039 until their .gdb_index sections can be recreated. The new command
2040 "set use-deprecated-index-sections on" will cause GDB to use any older
2041 .gdb_index sections it finds. This will restore performance, but the
2042 ability to set breakpoints on inlined functions will be lost in symbol
2043 files with older .gdb_index sections.
2045 The .gdb_index section has also been updated to record more information
2046 about each symbol. This speeds up the "info variables", "info functions"
2047 and "info types" commands when used with programs having the .gdb_index
2048 section, as well as speeding up debugging with shared libraries using
2049 the .gdb_index section.
2051 * Ada support for GDB/MI Variable Objects has been added.
2053 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2058 ** New command -info-os is the MI equivalent of "info os".
2060 ** Output logs ("set logging" and related) now include MI output.
2064 ** "set use-deprecated-index-sections on|off"
2065 "show use-deprecated-index-sections on|off"
2066 Controls the use of deprecated .gdb_index sections.
2068 ** "catch load" and "catch unload" can be used to stop when a shared
2069 library is loaded or unloaded, respectively.
2071 ** "enable count" can be used to auto-disable a breakpoint after
2074 ** "info vtbl" can be used to show the virtual method tables for
2075 C++ and Java objects.
2077 ** "explore" and its sub commands "explore value" and "explore type"
2078 can be used to recursively explore values and types of
2079 expressions. These commands are available only if GDB is
2080 configured with '--with-python'.
2082 ** "info auto-load" shows status of all kinds of auto-loaded files,
2083 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2084 sequences of commands files, "info auto-load python-scripts"
2085 shows status of auto-loading Python script files,
2086 "info auto-load local-gdbinit" shows status of loading init file
2087 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2088 status of inferior specific thread debugging shared library loading.
2090 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2091 and "show auto-load-scripts" commands have been deprecated, use their
2092 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2093 and "show auto-load python-scripts" counterparts instead.
2095 ** "dprintf location,format,args..." creates a dynamic printf, which
2096 is basically a breakpoint that does a printf and immediately
2097 resumes your program's execution, so it is like a printf that you
2098 can insert dynamically at runtime instead of at compiletime.
2100 ** "set print symbol"
2102 Controls whether GDB attempts to display the symbol, if any,
2103 corresponding to addresses it prints. This defaults to "on", but
2104 you can set it to "off" to restore GDB's previous behavior.
2106 * Deprecated commands
2108 ** For the Renesas Super-H architecture, the "regs" command has been
2109 deprecated, and "info all-registers" should be used instead.
2113 Renesas RL78 rl78-*-elf
2114 HP OpenVMS ia64 ia64-hp-openvms*
2116 * GDBserver supports evaluation of breakpoint conditions. When
2117 support is advertised by GDBserver, GDB may be told to send the
2118 breakpoint conditions in bytecode form to GDBserver. GDBserver
2119 will only report the breakpoint trigger to GDB when its condition
2124 set mips compression
2125 show mips compression
2126 Select the compressed ISA encoding used in functions that have no symbol
2127 information available. The encoding can be set to either of:
2130 and is updated automatically from ELF file flags if available.
2132 set breakpoint condition-evaluation
2133 show breakpoint condition-evaluation
2134 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2135 GDBserver ("target"). Default option "auto" chooses the most efficient
2137 This option can improve debugger efficiency depending on the speed of the
2141 Disable auto-loading globally.
2144 Show auto-loading setting of all kinds of auto-loaded files.
2146 set auto-load gdb-scripts on|off
2147 show auto-load gdb-scripts
2148 Control auto-loading of GDB canned sequences of commands files.
2150 set auto-load python-scripts on|off
2151 show auto-load python-scripts
2152 Control auto-loading of Python script files.
2154 set auto-load local-gdbinit on|off
2155 show auto-load local-gdbinit
2156 Control loading of init file (.gdbinit) from current directory.
2158 set auto-load libthread-db on|off
2159 show auto-load libthread-db
2160 Control auto-loading of inferior specific thread debugging shared library.
2162 set auto-load scripts-directory <dir1>[:<dir2>...]
2163 show auto-load scripts-directory
2164 Set a list of directories from which to load auto-loaded scripts.
2165 Automatically loaded Python scripts and GDB scripts are located in one
2166 of the directories listed by this option.
2167 The delimiter (':' above) may differ according to the host platform.
2169 set auto-load safe-path <dir1>[:<dir2>...]
2170 show auto-load safe-path
2171 Set a list of directories from which it is safe to auto-load files.
2172 The delimiter (':' above) may differ according to the host platform.
2174 set debug auto-load on|off
2175 show debug auto-load
2176 Control display of debugging info for auto-loading the files above.
2178 set dprintf-style gdb|call|agent
2180 Control the way in which a dynamic printf is performed; "gdb"
2181 requests a GDB printf command, while "call" causes dprintf to call a
2182 function in the inferior. "agent" requests that the target agent
2183 (such as GDBserver) do the printing.
2185 set dprintf-function <expr>
2186 show dprintf-function
2187 set dprintf-channel <expr>
2188 show dprintf-channel
2189 Set the function and optional first argument to the call when using
2190 the "call" style of dynamic printf.
2192 set disconnected-dprintf on|off
2193 show disconnected-dprintf
2194 Control whether agent-style dynamic printfs continue to be in effect
2195 after GDB disconnects.
2197 * New configure options
2199 --with-auto-load-dir
2200 Configure default value for the 'set auto-load scripts-directory'
2201 setting above. It defaults to '$debugdir:$datadir/auto-load',
2202 $debugdir representing global debugging info directories (available
2203 via 'show debug-file-directory') and $datadir representing GDB's data
2204 directory (available via 'show data-directory').
2206 --with-auto-load-safe-path
2207 Configure default value for the 'set auto-load safe-path' setting
2208 above. It defaults to the --with-auto-load-dir setting.
2210 --without-auto-load-safe-path
2211 Set 'set auto-load safe-path' to '/', effectively disabling this
2214 * New remote packets
2216 z0/z1 conditional breakpoints extension
2218 The z0/z1 breakpoint insertion packets have been extended to carry
2219 a list of conditional expressions over to the remote stub depending on the
2220 condition evaluation mode. The use of this extension can be controlled
2221 via the "set remote conditional-breakpoints-packet" command.
2225 Specify the signals which the remote stub may pass to the debugged
2226 program without GDB involvement.
2228 * New command line options
2230 --init-command=FILE, -ix Like --command, -x but execute it
2231 before loading inferior.
2232 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2233 execute it before loading inferior.
2235 *** Changes in GDB 7.4
2237 * GDB now handles ambiguous linespecs more consistently; the existing
2238 FILE:LINE support has been expanded to other types of linespecs. A
2239 breakpoint will now be set on all matching locations in all
2240 inferiors, and locations will be added or removed according to
2243 * GDB now allows you to skip uninteresting functions and files when
2244 stepping with the "skip function" and "skip file" commands.
2246 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2247 and "show remote hardware-watchpoint-length-limit". These allows to
2248 set or show the maximum length limit (in bytes) of a remote
2249 target hardware watchpoint.
2251 This allows e.g. to use "unlimited" hardware watchpoints with the
2252 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2253 watchpoints are slower than real hardware watchpoints but are
2254 significantly faster than gdb software watchpoints.
2258 ** The register_pretty_printer function in module gdb.printing now takes
2259 an optional `replace' argument. If True, the new printer replaces any
2262 ** The "maint set python print-stack on|off" command has been
2263 deprecated and will be deleted in GDB 7.5.
2264 A new command: "set python print-stack none|full|message" has
2265 replaced it. Additionally, the default for "print-stack" is
2266 now "message", which just prints the error message without
2269 ** A prompt substitution hook (prompt_hook) is now available to the
2272 ** A new Python module, gdb.prompt has been added to the GDB Python
2273 modules library. This module provides functionality for
2274 escape sequences in prompts (used by set/show
2275 extended-prompt). These escape sequences are replaced by their
2276 corresponding value.
2278 ** Python commands and convenience-functions located in
2279 'data-directory'/python/gdb/command and
2280 'data-directory'/python/gdb/function are now automatically loaded
2283 ** Blocks now provide four new attributes. global_block and
2284 static_block will return the global and static blocks
2285 respectively. is_static and is_global are boolean attributes
2286 that indicate if the block is one of those two types.
2288 ** Symbols now provide the "type" attribute, the type of the symbol.
2290 ** The "gdb.breakpoint" function has been deprecated in favor of
2293 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2294 of a function. This class is based on the "finish" command
2295 available in the CLI.
2297 ** Type objects for struct and union types now allow access to
2298 the fields using standard Python dictionary (mapping) methods.
2299 For example, "some_type['myfield']" now works, as does
2300 "some_type.items()".
2302 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2305 ** A new function, "deep_items" has been added to the gdb.types
2306 module in the GDB Python modules library. This function returns
2307 an iterator over the fields of a struct or union type. Unlike
2308 the standard Python "iteritems" method, it will recursively traverse
2309 any anonymous fields.
2313 ** "*stopped" events can report several new "reason"s, such as
2316 ** Breakpoint changes are now notified using new async records, like
2317 "=breakpoint-modified".
2319 ** New command -ada-task-info.
2321 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2322 $sdir specifies the default system locations of shared libraries.
2323 $pdir specifies the directory where the libpthread used by the application
2326 GDB no longer looks in $sdir and $pdir after it has searched the directories
2327 mentioned in libthread-db-search-path. If you want to search those
2328 directories, they must be specified in libthread-db-search-path.
2329 The default value of libthread-db-search-path on GNU/Linux and Solaris
2330 systems is now "$sdir:$pdir".
2332 $pdir is not supported by gdbserver, it is currently ignored.
2333 $sdir is supported by gdbserver.
2335 * New configure option --with-iconv-bin.
2336 When using the internationalization support like the one in the GNU C
2337 library, GDB will invoke the "iconv" program to get a list of supported
2338 character sets. If this program lives in a non-standard location, one can
2339 use this option to specify where to find it.
2341 * When natively debugging programs on PowerPC BookE processors running
2342 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2343 watchpoints, which specify a mask in addition to an address to watch.
2344 The mask specifies that some bits of an address (the bits which are
2345 reset in the mask) should be ignored when matching the address accessed
2346 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2347 section in the user manual for more details.
2349 * The new option --once causes GDBserver to stop listening for connections once
2350 the first connection is made. The listening port used by GDBserver will
2351 become available after that.
2353 * New commands "info macros" and "alias" have been added.
2355 * New function parameters suffix @entry specifies value of function parameter
2356 at the time the function got called. Entry values are available only since
2362 "!" is now an alias of the "shell" command.
2363 Note that no space is needed between "!" and SHELL COMMAND.
2367 watch EXPRESSION mask MASK_VALUE
2368 The watch command now supports the mask argument which allows creation
2369 of masked watchpoints, if the current architecture supports this feature.
2371 info auto-load-scripts [REGEXP]
2372 This command was formerly named "maintenance print section-scripts".
2373 It is now generally useful and is no longer a maintenance-only command.
2375 info macro [-all] [--] MACRO
2376 The info macro command has new options `-all' and `--'. The first for
2377 printing all definitions of a macro. The second for explicitly specifying
2378 the end of arguments and the beginning of the macro name in case the macro
2379 name starts with a hyphen.
2381 collect[/s] EXPRESSIONS
2382 The tracepoint collect command now takes an optional modifier "/s"
2383 that directs it to dereference pointer-to-character types and
2384 collect the bytes of memory up to a zero byte. The behavior is
2385 similar to what you see when you use the regular print command on a
2386 string. An optional integer following the "/s" sets a bound on the
2387 number of bytes that will be collected.
2390 The trace start command now interprets any supplied arguments as a
2391 note to be recorded with the trace run, with an effect similar to
2392 setting the variable trace-notes.
2395 The trace stop command now interprets any arguments as a note to be
2396 mentioned along with the tstatus report that the trace was stopped
2397 with a command. The effect is similar to setting the variable
2400 * Tracepoints can now be enabled and disabled at any time after a trace
2401 experiment has been started using the standard "enable" and "disable"
2402 commands. It is now possible to start a trace experiment with no enabled
2403 tracepoints; GDB will display a warning, but will allow the experiment to
2404 begin, assuming that tracepoints will be enabled as needed while the trace
2407 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2408 locations with 4-byte instructions, when they were previously
2409 limited to locations with instructions of 5 bytes or longer.
2413 set debug dwarf2-read
2414 show debug dwarf2-read
2415 Turns on or off display of debugging messages related to reading
2416 DWARF debug info. The default is off.
2418 set debug symtab-create
2419 show debug symtab-create
2420 Turns on or off display of debugging messages related to symbol table
2421 creation. The default is off.
2424 show extended-prompt
2425 Set the GDB prompt, and allow escape sequences to be inserted to
2426 display miscellaneous information (see 'help set extended-prompt'
2427 for the list of sequences). This prompt (and any information
2428 accessed through the escape sequences) is updated every time the
2429 prompt is displayed.
2431 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2432 show print entry-values
2433 Set printing of frame argument values at function entry. In some cases
2434 GDB can determine the value of function argument which was passed by the
2435 function caller, even if the value was modified inside the called function.
2437 set debug entry-values
2438 show debug entry-values
2439 Control display of debugging info for determining frame argument values at
2440 function entry and virtual tail call frames.
2442 set basenames-may-differ
2443 show basenames-may-differ
2444 Set whether a source file may have multiple base names.
2445 (A "base name" is the name of a file with the directory part removed.
2446 Example: The base name of "/home/user/hello.c" is "hello.c".)
2447 If set, GDB will canonicalize file names (e.g., expand symlinks)
2448 before comparing them. Canonicalization is an expensive operation,
2449 but it allows the same file be known by more than one base name.
2450 If not set (the default), all source files are assumed to have just
2451 one base name, and gdb will do file name comparisons more efficiently.
2457 Set a user name and notes for the current and any future trace runs.
2458 This is useful for long-running and/or disconnected traces, to
2459 inform others (or yourself) as to who is running the trace, supply
2460 contact information, or otherwise explain what is going on.
2462 set trace-stop-notes
2463 show trace-stop-notes
2464 Set a note attached to the trace run, that is displayed when the
2465 trace has been stopped by a tstop command. This is useful for
2466 instance as an explanation, if you are stopping a trace run that was
2467 started by someone else.
2469 * New remote packets
2473 Dynamically enable a tracepoint in a started trace experiment.
2477 Dynamically disable a tracepoint in a started trace experiment.
2481 Set the user and notes of the trace run.
2485 Query the current status of a tracepoint.
2489 Query the minimum length of instruction at which a fast tracepoint may
2492 * Dcache size (number of lines) and line-size are now runtime-configurable
2493 via "set dcache line" and "set dcache line-size" commands.
2497 Texas Instruments TMS320C6x tic6x-*-*
2501 Renesas RL78 rl78-*-elf
2503 *** Changes in GDB 7.3.1
2505 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2507 *** Changes in GDB 7.3
2509 * GDB has a new command: "thread find [REGEXP]".
2510 It finds the thread id whose name, target id, or thread extra info
2511 matches the given regular expression.
2513 * The "catch syscall" command now works on mips*-linux* targets.
2515 * The -data-disassemble MI command now supports modes 2 and 3 for
2516 dumping the instruction opcodes.
2518 * New command line options
2520 -data-directory DIR Specify DIR as the "data-directory".
2521 This is mostly for testing purposes.
2523 * The "maint set python auto-load on|off" command has been renamed to
2524 "set auto-load-scripts on|off".
2526 * GDB has a new command: "set directories".
2527 It is like the "dir" command except that it replaces the
2528 source path list instead of augmenting it.
2530 * GDB now understands thread names.
2532 On GNU/Linux, "info threads" will display the thread name as set by
2533 prctl or pthread_setname_np.
2535 There is also a new command, "thread name", which can be used to
2536 assign a name internally for GDB to display.
2539 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2540 has been integrated into GDB.
2544 ** The function gdb.Write now accepts an optional keyword 'stream'.
2545 This keyword, when provided, will direct the output to either
2546 stdout, stderr, or GDB's logging output.
2548 ** Parameters can now be be sub-classed in Python, and in particular
2549 you may implement the get_set_doc and get_show_doc functions.
2550 This improves how Parameter set/show documentation is processed
2551 and allows for more dynamic content.
2553 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2554 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2555 have an is_valid method.
2557 ** Breakpoints can now be sub-classed in Python, and in particular
2558 you may implement a 'stop' function that is executed each time
2559 the inferior reaches that breakpoint.
2561 ** New function gdb.lookup_global_symbol looks up a global symbol.
2563 ** GDB values in Python are now callable if the value represents a
2564 function. For example, if 'some_value' represents a function that
2565 takes two integer parameters and returns a value, you can call
2566 that function like so:
2568 result = some_value (10,20)
2570 ** Module gdb.types has been added.
2571 It contains a collection of utilities for working with gdb.Types objects:
2572 get_basic_type, has_field, make_enum_dict.
2574 ** Module gdb.printing has been added.
2575 It contains utilities for writing and registering pretty-printers.
2576 New classes: PrettyPrinter, SubPrettyPrinter,
2577 RegexpCollectionPrettyPrinter.
2578 New function: register_pretty_printer.
2580 ** New commands "info pretty-printers", "enable pretty-printer" and
2581 "disable pretty-printer" have been added.
2583 ** gdb.parameter("directories") is now available.
2585 ** New function gdb.newest_frame returns the newest frame in the
2588 ** The gdb.InferiorThread class has a new "name" attribute. This
2589 holds the thread's name.
2591 ** Python Support for Inferior events.
2592 Python scripts can add observers to be notified of events
2593 occurring in the process being debugged.
2594 The following events are currently supported:
2595 - gdb.events.cont Continue event.
2596 - gdb.events.exited Inferior exited event.
2597 - gdb.events.stop Signal received, and Breakpoint hit events.
2601 ** GDB now puts template parameters in scope when debugging in an
2602 instantiation. For example, if you have:
2604 template<int X> int func (void) { return X; }
2606 then if you step into func<5>, "print X" will show "5". This
2607 feature requires proper debuginfo support from the compiler; it
2608 was added to GCC 4.5.
2610 ** The motion commands "next", "finish", "until", and "advance" now
2611 work better when exceptions are thrown. In particular, GDB will
2612 no longer lose control of the inferior; instead, the GDB will
2613 stop the inferior at the point at which the exception is caught.
2614 This functionality requires a change in the exception handling
2615 code that was introduced in GCC 4.5.
2617 * GDB now follows GCC's rules on accessing volatile objects when
2618 reading or writing target state during expression evaluation.
2619 One notable difference to prior behavior is that "print x = 0"
2620 no longer generates a read of x; the value of the assignment is
2621 now always taken directly from the value being assigned.
2623 * GDB now has some support for using labels in the program's source in
2624 linespecs. For instance, you can use "advance label" to continue
2625 execution to a label.
2627 * GDB now has support for reading and writing a new .gdb_index
2628 section. This section holds a fast index of DWARF debugging
2629 information and can be used to greatly speed up GDB startup and
2630 operation. See the documentation for `save gdb-index' for details.
2632 * The "watch" command now accepts an optional "-location" argument.
2633 When used, this causes GDB to watch the memory referred to by the
2634 expression. Such a watchpoint is never deleted due to it going out
2637 * GDB now supports thread debugging of core dumps on GNU/Linux.
2639 GDB now activates thread debugging using the libthread_db library
2640 when debugging GNU/Linux core dumps, similarly to when debugging
2641 live processes. As a result, when debugging a core dump file, GDB
2642 is now able to display pthread_t ids of threads. For example, "info
2643 threads" shows the same output as when debugging the process when it
2644 was live. In earlier releases, you'd see something like this:
2647 * 1 LWP 6780 main () at main.c:10
2649 While now you see this:
2652 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2654 It is also now possible to inspect TLS variables when debugging core
2657 When debugging a core dump generated on a machine other than the one
2658 used to run GDB, you may need to point GDB at the correct
2659 libthread_db library with the "set libthread-db-search-path"
2660 command. See the user manual for more details on this command.
2662 * When natively debugging programs on PowerPC BookE processors running
2663 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2664 which stop execution of the inferior whenever it executes an instruction
2665 at any address within the specified range. See the "PowerPC Embedded"
2666 section in the user manual for more details.
2668 * New features in the GDB remote stub, GDBserver
2670 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2671 and i686 LynxOS (version 5.x).
2673 ** GDBserver is now supported on Blackfin Linux.
2675 * New native configurations
2677 ia64 HP-UX ia64-*-hpux*
2681 Analog Devices, Inc. Blackfin Processor bfin-*
2683 * Ada task switching is now supported on sparc-elf targets when
2684 debugging a program using the Ravenscar Profile. For more information,
2685 see the "Tasking Support when using the Ravenscar Profile" section
2686 in the GDB user manual.
2688 * Guile support was removed.
2690 * New features in the GNU simulator
2692 ** The --map-info flag lists all known core mappings.
2694 ** CFI flashes may be simulated via the "cfi" device.
2696 *** Changes in GDB 7.2
2698 * Shared library support for remote targets by default
2700 When GDB is configured for a generic, non-OS specific target, like
2701 for example, --target=arm-eabi or one of the many *-*-elf targets,
2702 GDB now queries remote stubs for loaded shared libraries using the
2703 `qXfer:libraries:read' packet. Previously, shared library support
2704 was always disabled for such configurations.
2708 ** Argument Dependent Lookup (ADL)
2710 In C++ ADL lookup directs function search to the namespaces of its
2711 arguments even if the namespace has not been imported.
2721 Here the compiler will search for `foo' in the namespace of 'b'
2722 and find A::foo. GDB now supports this. This construct is commonly
2723 used in the Standard Template Library for operators.
2725 ** Improved User Defined Operator Support
2727 In addition to member operators, GDB now supports lookup of operators
2728 defined in a namespace and imported with a `using' directive, operators
2729 defined in the global scope, operators imported implicitly from an
2730 anonymous namespace, and the ADL operators mentioned in the previous
2732 GDB now also supports proper overload resolution for all the previously
2733 mentioned flavors of operators.
2735 ** static const class members
2737 Printing of static const class members that are initialized in the
2738 class definition has been fixed.
2740 * Windows Thread Information Block access.
2742 On Windows targets, GDB now supports displaying the Windows Thread
2743 Information Block (TIB) structure. This structure is visible either
2744 by using the new command `info w32 thread-information-block' or, by
2745 dereferencing the new convenience variable named `$_tlb', a
2746 thread-specific pointer to the TIB. This feature is also supported
2747 when remote debugging using GDBserver.
2749 * Static tracepoints
2751 Static tracepoints are calls in the user program into a tracing
2752 library. One such library is a port of the LTTng kernel tracer to
2753 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2754 When debugging with GDBserver, GDB now supports combining the GDB
2755 tracepoint machinery with such libraries. For example: the user can
2756 use GDB to probe a static tracepoint marker (a call from the user
2757 program into the tracing library) with the new "strace" command (see
2758 "New commands" below). This creates a "static tracepoint" in the
2759 breakpoint list, that can be manipulated with the same feature set
2760 as fast and regular tracepoints. E.g., collect registers, local and
2761 global variables, collect trace state variables, and define
2762 tracepoint conditions. In addition, the user can collect extra
2763 static tracepoint marker specific data, by collecting the new
2764 $_sdata internal variable. When analyzing the trace buffer, you can
2765 inspect $_sdata like any other variable available to GDB. For more
2766 information, see the "Tracepoints" chapter in GDB user manual. New
2767 remote packets have been defined to support static tracepoints, see
2768 the "New remote packets" section below.
2770 * Better reconstruction of tracepoints after disconnected tracing
2772 GDB will attempt to download the original source form of tracepoint
2773 definitions when starting a trace run, and then will upload these
2774 upon reconnection to the target, resulting in a more accurate
2775 reconstruction of the tracepoints that are in use on the target.
2779 You can now exercise direct control over the ways that GDB can
2780 affect your program. For instance, you can disallow the setting of
2781 breakpoints, so that the program can run continuously (assuming
2782 non-stop mode). In addition, the "observer" variable is available
2783 to switch all of the different controls; in observer mode, GDB
2784 cannot affect the target's behavior at all, which is useful for
2785 tasks like diagnosing live systems in the field.
2787 * The new convenience variable $_thread holds the number of the
2790 * New remote packets
2794 Return the address of the Windows Thread Information Block of a given thread.
2798 In response to several of the tracepoint packets, the target may now
2799 also respond with a number of intermediate `qRelocInsn' request
2800 packets before the final result packet, to have GDB handle
2801 relocating an instruction to execute at a different address. This
2802 is particularly useful for stubs that support fast tracepoints. GDB
2803 reports support for this feature in the qSupported packet.
2807 List static tracepoint markers in the target program.
2811 List static tracepoint markers at a given address in the target
2814 qXfer:statictrace:read
2816 Read the static trace data collected (by a `collect $_sdata'
2817 tracepoint action). The remote stub reports support for this packet
2818 to gdb's qSupported query.
2822 Send the current settings of GDB's permission flags.
2826 Send part of the source (textual) form of a tracepoint definition,
2827 which includes location, conditional, and action list.
2829 * The source command now accepts a -s option to force searching for the
2830 script in the source search path even if the script name specifies
2833 * New features in the GDB remote stub, GDBserver
2835 - GDBserver now support tracepoints (including fast tracepoints, and
2836 static tracepoints). The feature is currently supported by the
2837 i386-linux and amd64-linux builds. See the "Tracepoints support
2838 in gdbserver" section in the manual for more information.
2840 GDBserver JIT compiles the tracepoint's conditional agent
2841 expression bytecode into native code whenever possible for low
2842 overhead dynamic tracepoints conditionals. For such tracepoints,
2843 an expression that examines program state is evaluated when the
2844 tracepoint is reached, in order to determine whether to capture
2845 trace data. If the condition is simple and false, processing the
2846 tracepoint finishes very quickly and no data is gathered.
2848 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2849 for static tracepoints support.
2851 - GDBserver now supports x86_64 Windows 64-bit debugging.
2853 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2854 it understands register description.
2856 * The --batch flag now disables pagination and queries.
2858 * X86 general purpose registers
2860 GDB now supports reading/writing byte, word and double-word x86
2861 general purpose registers directly. This means you can use, say,
2862 $ah or $ax to refer, respectively, to the byte register AH and
2863 16-bit word register AX that are actually portions of the 32-bit
2864 register EAX or 64-bit register RAX.
2866 * The `commands' command now accepts a range of breakpoints to modify.
2867 A plain `commands' following a command that creates multiple
2868 breakpoints affects all the breakpoints set by that command. This
2869 applies to breakpoints set by `rbreak', and also applies when a
2870 single `break' command creates multiple breakpoints (e.g.,
2871 breakpoints on overloaded c++ functions).
2873 * The `rbreak' command now accepts a filename specification as part of
2874 its argument, limiting the functions selected by the regex to those
2875 in the specified file.
2877 * Support for remote debugging Windows and SymbianOS shared libraries
2878 from Unix hosts has been improved. Non Windows GDB builds now can
2879 understand target reported file names that follow MS-DOS based file
2880 system semantics, such as file names that include drive letters and
2881 use the backslash character as directory separator. This makes it
2882 possible to transparently use the "set sysroot" and "set
2883 solib-search-path" on Unix hosts to point as host copies of the
2884 target's shared libraries. See the new command "set
2885 target-file-system-kind" described below, and the "Commands to
2886 specify files" section in the user manual for more information.
2890 eval template, expressions...
2891 Convert the values of one or more expressions under the control
2892 of the string template to a command line, and call it.
2894 set target-file-system-kind unix|dos-based|auto
2895 show target-file-system-kind
2896 Set or show the assumed file system kind for target reported file
2899 save breakpoints <filename>
2900 Save all current breakpoint definitions to a file suitable for use
2901 in a later debugging session. To read the saved breakpoint
2902 definitions, use the `source' command.
2904 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2907 info static-tracepoint-markers
2908 Display information about static tracepoint markers in the target.
2910 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2911 Define a static tracepoint by probing a marker at the given
2912 function, line, address, or marker ID.
2916 Enable and disable observer mode.
2918 set may-write-registers on|off
2919 set may-write-memory on|off
2920 set may-insert-breakpoints on|off
2921 set may-insert-tracepoints on|off
2922 set may-insert-fast-tracepoints on|off
2923 set may-interrupt on|off
2924 Set individual permissions for GDB effects on the target. Note that
2925 some of these settings can have undesirable or surprising
2926 consequences, particularly when changed in the middle of a session.
2927 For instance, disabling the writing of memory can prevent
2928 breakpoints from being inserted, cause single-stepping to fail, or
2929 even crash your program, if you disable after breakpoints have been
2930 inserted. However, GDB should not crash.
2932 set record memory-query on|off
2933 show record memory-query
2934 Control whether to stop the inferior if memory changes caused
2935 by an instruction cannot be recorded.
2940 The disassemble command now supports "start,+length" form of two arguments.
2944 ** GDB now provides a new directory location, called the python directory,
2945 where Python scripts written for GDB can be installed. The location
2946 of that directory is <data-directory>/python, where <data-directory>
2947 is the GDB data directory. For more details, see section `Scripting
2948 GDB using Python' in the manual.
2950 ** The GDB Python API now has access to breakpoints, symbols, symbol
2951 tables, program spaces, inferiors, threads and frame's code blocks.
2952 Additionally, GDB Parameters can now be created from the API, and
2953 manipulated via set/show in the CLI.
2955 ** New functions gdb.target_charset, gdb.target_wide_charset,
2956 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2958 ** New exception gdb.GdbError.
2960 ** Pretty-printers are now also looked up in the current program space.
2962 ** Pretty-printers can now be individually enabled and disabled.
2964 ** GDB now looks for names of Python scripts to auto-load in a
2965 special section named `.debug_gdb_scripts', in addition to looking
2966 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2968 * Tracepoint actions were unified with breakpoint commands. In particular,
2969 there are no longer differences in "info break" output for breakpoints and
2970 tracepoints and the "commands" command can be used for both tracepoints and
2971 regular breakpoints.
2975 ARM Symbian arm*-*-symbianelf*
2977 * D language support.
2978 GDB now supports debugging programs written in the D programming
2981 * GDB now supports the extended ptrace interface for PowerPC which is
2982 available since Linux kernel version 2.6.34. This automatically enables
2983 any hardware breakpoints and additional hardware watchpoints available in
2984 the processor. The old ptrace interface exposes just one hardware
2985 watchpoint and no hardware breakpoints.
2987 * GDB is now able to use the Data Value Compare (DVC) register available on
2988 embedded PowerPC processors to implement in hardware simple watchpoint
2989 conditions of the form:
2991 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2993 This works in native GDB running on Linux kernels with the extended ptrace
2994 interface mentioned above.
2996 *** Changes in GDB 7.1
3000 ** Namespace Support
3002 GDB now supports importing of namespaces in C++. This enables the
3003 user to inspect variables from imported namespaces. Support for
3004 namepace aliasing has also been added. So, if a namespace is
3005 aliased in the current scope (e.g. namepace C=A; ) the user can
3006 print variables using the alias (e.g. (gdb) print C::x).
3010 All known bugs relating to the printing of virtual base class were
3011 fixed. It is now possible to call overloaded static methods using a
3016 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3017 and reinterpret_cast<> are now handled by the C++ expression parser.
3021 Xilinx MicroBlaze microblaze-*-*
3026 Xilinx MicroBlaze microblaze
3029 * Multi-program debugging.
3031 GDB now has support for multi-program (a.k.a. multi-executable or
3032 multi-exec) debugging. This allows for debugging multiple inferiors
3033 simultaneously each running a different program under the same GDB
3034 session. See "Debugging Multiple Inferiors and Programs" in the
3035 manual for more information. This implied some user visible changes
3036 in the multi-inferior support. For example, "info inferiors" now
3037 lists inferiors that are not running yet or that have exited
3038 already. See also "New commands" and "New options" below.
3040 * New tracing features
3042 GDB's tracepoint facility now includes several new features:
3044 ** Trace state variables
3046 GDB tracepoints now include support for trace state variables, which
3047 are variables managed by the target agent during a tracing
3048 experiment. They are useful for tracepoints that trigger each
3049 other, so for instance one tracepoint can count hits in a variable,
3050 and then a second tracepoint has a condition that is true when the
3051 count reaches a particular value. Trace state variables share the
3052 $-syntax of GDB convenience variables, and can appear in both
3053 tracepoint actions and condition expressions. Use the "tvariable"
3054 command to create, and "info tvariables" to view; see "Trace State
3055 Variables" in the manual for more detail.
3059 GDB now includes an option for defining fast tracepoints, which
3060 targets may implement more efficiently, such as by installing a jump
3061 into the target agent rather than a trap instruction. The resulting
3062 speedup can be by two orders of magnitude or more, although the
3063 tradeoff is that some program locations on some target architectures
3064 might not allow fast tracepoint installation, for instance if the
3065 instruction to be replaced is shorter than the jump. To request a
3066 fast tracepoint, use the "ftrace" command, with syntax identical to
3067 the regular trace command.
3069 ** Disconnected tracing
3071 It is now possible to detach GDB from the target while it is running
3072 a trace experiment, then reconnect later to see how the experiment
3073 is going. In addition, a new variable disconnected-tracing lets you
3074 tell the target agent whether to continue running a trace if the
3075 connection is lost unexpectedly.
3079 GDB now has the ability to save the trace buffer into a file, and
3080 then use that file as a target, similarly to you can do with
3081 corefiles. You can select trace frames, print data that was
3082 collected in them, and use tstatus to display the state of the
3083 tracing run at the moment that it was saved. To create a trace
3084 file, use "tsave <filename>", and to use it, do "target tfile
3087 ** Circular trace buffer
3089 You can ask the target agent to handle the trace buffer as a
3090 circular buffer, discarding the oldest trace frames to make room for
3091 newer ones, by setting circular-trace-buffer to on. This feature may
3092 not be available for all target agents.
3097 The disassemble command, when invoked with two arguments, now requires
3098 the arguments to be comma-separated.
3101 The info variables command now displays variable definitions. Files
3102 which only declare a variable are not shown.
3105 The source command is now capable of sourcing Python scripts.
3106 This feature is dependent on the debugger being build with Python
3109 Related to this enhancement is also the introduction of a new command
3110 "set script-extension" (see below).
3112 * New commands (for set/show, see "New options" below)
3114 record save [<FILENAME>]
3115 Save a file (in core file format) containing the process record
3116 execution log for replay debugging at a later time.
3118 record restore <FILENAME>
3119 Restore the process record execution log that was saved at an
3120 earlier time, for replay debugging.
3122 add-inferior [-copies <N>] [-exec <FILENAME>]
3125 clone-inferior [-copies <N>] [ID]
3126 Make a new inferior ready to execute the same program another
3127 inferior has loaded.
3132 maint info program-spaces
3133 List the program spaces loaded into GDB.
3135 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3136 show remote interrupt-sequence
3137 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3138 as the sequence to the remote target in order to interrupt the execution.
3139 Ctrl-C is a default. Some system prefers BREAK which is high level of
3140 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3141 Magic SysRq g. It is BREAK signal and character 'g'.
3143 set remote interrupt-on-connect [on | off]
3144 show remote interrupt-on-connect
3145 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3146 remote target when gdb connects to it. This is needed when you debug
3149 set remotebreak [on | off]
3151 Deprecated. Use "set/show remote interrupt-sequence" instead.
3153 tvariable $NAME [ = EXP ]
3154 Create or modify a trace state variable.
3157 List trace state variables and their values.
3159 delete tvariable $NAME ...
3160 Delete one or more trace state variables.
3163 Evaluate the given expressions without collecting anything into the
3164 trace buffer. (Valid in tracepoint actions only.)
3166 ftrace FN / FILE:LINE / *ADDR
3167 Define a fast tracepoint at the given function, line, or address.
3169 * New expression syntax
3171 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3172 GDB now parses 0b101010 identically with 42.
3176 set follow-exec-mode new|same
3177 show follow-exec-mode
3178 Control whether GDB reuses the same inferior across an exec call or
3179 creates a new one. This is useful to be able to restart the old
3180 executable after the inferior having done an exec call.
3182 set default-collect EXPR, ...
3183 show default-collect
3184 Define a list of expressions to be collected at each tracepoint.
3185 This is a useful way to ensure essential items are not overlooked,
3186 such as registers or a critical global variable.
3188 set disconnected-tracing
3189 show disconnected-tracing
3190 If set to 1, the target is instructed to continue tracing if it
3191 loses its connection to GDB. If 0, the target is to stop tracing
3194 set circular-trace-buffer
3195 show circular-trace-buffer
3196 If set to on, the target is instructed to use a circular trace buffer
3197 and discard the oldest trace frames instead of stopping the trace due
3198 to a full trace buffer. If set to off, the trace stops when the buffer
3199 fills up. Some targets may not support this.
3201 set script-extension off|soft|strict
3202 show script-extension
3203 If set to "off", the debugger does not perform any script language
3204 recognition, and all sourced files are assumed to be GDB scripts.
3205 If set to "soft" (the default), files are sourced according to
3206 filename extension, falling back to GDB scripts if the first
3208 If set to "strict", files are sourced according to filename extension.
3210 set ada trust-PAD-over-XVS on|off
3211 show ada trust-PAD-over-XVS
3212 If off, activate a workaround against a bug in the debugging information
3213 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3214 the GCC sources for more information about the GNAT encoding and
3215 PAD types in particular). It is always safe to set this option to
3216 off, but this introduces a slight performance penalty. The default
3219 * Python API Improvements
3221 ** GDB provides the new class gdb.LazyString. This is useful in
3222 some pretty-printing cases. The new method gdb.Value.lazy_string
3223 provides a simple way to create objects of this type.
3225 ** The fields returned by gdb.Type.fields now have an
3226 `is_base_class' attribute.
3228 ** The new method gdb.Type.range returns the range of an array type.
3230 ** The new method gdb.parse_and_eval can be used to parse and
3231 evaluate an expression.
3233 * New remote packets
3236 Define a trace state variable.
3239 Get the current value of a trace state variable.
3242 Set desired tracing behavior upon disconnection.
3245 Set the trace buffer to be linear or circular.
3248 Get data about the tracepoints currently in use.
3252 Process record now works correctly with hardware watchpoints.
3254 Multiple bug fixes have been made to the mips-irix port, making it
3255 much more reliable. In particular:
3256 - Debugging threaded applications is now possible again. Previously,
3257 GDB would hang while starting the program, or while waiting for
3258 the program to stop at a breakpoint.
3259 - Attaching to a running process no longer hangs.
3260 - An error occurring while loading a core file has been fixed.
3261 - Changing the value of the PC register now works again. This fixes
3262 problems observed when using the "jump" command, or when calling
3263 a function from GDB, or even when assigning a new value to $pc.
3264 - With the "finish" and "return" commands, the return value for functions
3265 returning a small array is now correctly printed.
3266 - It is now possible to break on shared library code which gets executed
3267 during a shared library init phase (code executed while executing
3268 their .init section). Previously, the breakpoint would have no effect.
3269 - GDB is now able to backtrace through the signal handler for
3270 non-threaded programs.
3272 PIE (Position Independent Executable) programs debugging is now supported.
3273 This includes debugging execution of PIC (Position Independent Code) shared
3274 libraries although for that, it should be possible to run such libraries as an
3277 *** Changes in GDB 7.0
3279 * GDB now has an interface for JIT compilation. Applications that
3280 dynamically generate code can create symbol files in memory and register
3281 them with GDB. For users, the feature should work transparently, and
3282 for JIT developers, the interface is documented in the GDB manual in the
3283 "JIT Compilation Interface" chapter.
3285 * Tracepoints may now be conditional. The syntax is as for
3286 breakpoints; either an "if" clause appended to the "trace" command,
3287 or the "condition" command is available. GDB sends the condition to
3288 the target for evaluation using the same bytecode format as is used
3289 for tracepoint actions.
3291 * The disassemble command now supports: an optional /r modifier, print the
3292 raw instructions in hex as well as in symbolic form, and an optional /m
3293 modifier to print mixed source+assembly.
3295 * Process record and replay
3297 In a architecture environment that supports ``process record and
3298 replay'', ``process record and replay'' target can record a log of
3299 the process execution, and replay it with both forward and reverse
3302 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3303 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3304 set execution-direction {forward|reverse}, for targets that support
3307 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3308 feature is available with a native GDB running on kernel version
3311 * GDB now has support for multi-byte and wide character sets on the
3312 target. Strings whose character type is wchar_t, char16_t, or
3313 char32_t are now correctly printed. GDB supports wide- and unicode-
3314 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3315 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3316 `printf'. This feature requires iconv to work properly; if your
3317 system does not have a working iconv, GDB can use GNU libiconv. See
3318 the installation instructions for more information.
3320 * GDB now supports automatic retrieval of shared library files from
3321 remote targets. To use this feature, specify a system root that begins
3322 with the `remote:' prefix, either via the `set sysroot' command or via
3323 the `--with-sysroot' configure-time option.
3325 * "info sharedlibrary" now takes an optional regex of libraries to show,
3326 and it now reports if a shared library has no debugging information.
3328 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3329 now complete on file names.
3331 * When completing in expressions, gdb will attempt to limit
3332 completions to allowable structure or union fields, where appropriate.
3333 For instance, consider:
3335 # struct example { int f1; double f2; };
3336 # struct example variable;
3339 If the user types TAB at the end of this command line, the available
3340 completions will be "f1" and "f2".
3342 * Inlined functions are now supported. They show up in backtraces, and
3343 the "step", "next", and "finish" commands handle them automatically.
3345 * GDB now supports the token-splicing (##) and stringification (#)
3346 operators when expanding macros. It also supports variable-arity
3349 * GDB now supports inspecting extra signal information, exported by
3350 the new $_siginfo convenience variable. The feature is currently
3351 implemented on linux ARM, i386 and amd64.
3353 * GDB can now display the VFP floating point registers and NEON vector
3354 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3355 can provide these registers (requires Linux 2.6.30 or later). Remote
3356 and simulator targets may also provide them.
3358 * New remote packets
3361 Search memory for a sequence of bytes.
3364 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3365 operation over reliable transport links. Use of this packet is
3366 controlled by the `set remote noack-packet' command.
3369 Kill the process with the specified process ID. Use this in preference
3370 to `k' when multiprocess protocol extensions are supported.
3373 Obtains additional operating system information
3377 Read or write additional signal information.
3379 * Removed remote protocol undocumented extension
3381 An undocumented extension to the remote protocol's `S' stop reply
3382 packet that permited the stub to pass a process id was removed.
3383 Remote servers should use the `T' stop reply packet instead.
3385 * GDB now supports multiple function calling conventions according to the
3386 DWARF-2 DW_AT_calling_convention function attribute.
3388 * The SH target utilizes the aforementioned change to distinguish between gcc
3389 and Renesas calling convention. It also adds the new CLI commands
3390 `set/show sh calling-convention'.
3392 * GDB can now read compressed debug sections, as produced by GNU gold
3393 with the --compress-debug-sections=zlib flag.
3395 * 64-bit core files are now supported on AIX.
3397 * Thread switching is now supported on Tru64.
3399 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3400 which will be allocated using malloc later in program execution.
3402 * The qXfer:libraries:read remote procotol packet now allows passing a
3403 list of section offsets.
3405 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3406 conditions handling signals delivered during attach or thread creation
3407 have also been fixed.
3409 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3410 From the user's standpoint, all unqualified instances of True and False
3411 are treated as the standard definitions, regardless of context.
3413 * GDB now parses C++ symbol and type names more flexibly. For
3416 template<typename T> class C { };
3419 GDB will now correctly handle all of:
3421 ptype C<char const *>
3422 ptype C<char const*>
3423 ptype C<const char *>
3424 ptype C<const char*>
3426 * New features in the GDB remote stub, gdbserver
3428 - The "--wrapper" command-line argument tells gdbserver to use a
3429 wrapper program to launch programs for debugging.
3431 - On PowerPC and S/390 targets, it is now possible to use a single
3432 gdbserver executable to debug both 32-bit and 64-bit programs.
3433 (This requires gdbserver itself to be built as a 64-bit executable.)
3435 - gdbserver uses the new noack protocol mode for TCP connections to
3436 reduce communications latency, if also supported and enabled in GDB.
3438 - Support for the sparc64-linux-gnu target is now included in
3441 - The amd64-linux build of gdbserver now supports debugging both
3442 32-bit and 64-bit programs.
3444 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3445 now support hardware watchpoints, and will use them automatically
3450 GDB now has support for scripting using Python. Whether this is
3451 available is determined at configure time.
3453 New GDB commands can now be written in Python.
3455 * Ada tasking support
3457 Ada tasks can now be inspected in GDB. The following commands have
3461 Print the list of Ada tasks.
3463 Print detailed information about task number N.
3465 Print the task number of the current task.
3467 Switch the context of debugging to task number N.
3469 * Support for user-defined prefixed commands. The "define" command can
3470 add new commands to existing prefixes, e.g. "target".
3472 * Multi-inferior, multi-process debugging.
3474 GDB now has generalized support for multi-inferior debugging. See
3475 "Debugging Multiple Inferiors" in the manual for more information.
3476 Although availability still depends on target support, the command
3477 set is more uniform now. The GNU/Linux specific multi-forks support
3478 has been migrated to this new framework. This implied some user
3479 visible changes; see "New commands" and also "Removed commands"
3482 * Target descriptions can now describe the target OS ABI. See the
3483 "Target Description Format" section in the user manual for more
3486 * Target descriptions can now describe "compatible" architectures
3487 to indicate that the target can execute applications for a different
3488 architecture in addition to those for the main target architecture.
3489 See the "Target Description Format" section in the user manual for
3492 * Multi-architecture debugging.
3494 GDB now includes general supports for debugging applications on
3495 hybrid systems that use more than one single processor architecture
3496 at the same time. Each such hybrid architecture still requires
3497 specific support to be added. The only hybrid architecture supported
3498 in this version of GDB is the Cell Broadband Engine.
3500 * GDB now supports integrated debugging of Cell/B.E. applications that
3501 use both the PPU and SPU architectures. To enable support for hybrid
3502 Cell/B.E. debugging, you need to configure GDB to support both the
3503 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3504 --enable-targets configure option.
3506 * Non-stop mode debugging.
3508 For some targets, GDB now supports an optional mode of operation in
3509 which you can examine stopped threads while other threads continue
3510 to execute freely. This is referred to as non-stop mode, with the
3511 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3512 section in the user manual for more information.
3514 To be able to support remote non-stop debugging, a remote stub needs
3515 to implement the non-stop mode remote protocol extensions, as
3516 described in the "Remote Non-Stop" section of the user manual. The
3517 GDB remote stub, gdbserver, has been adjusted to support these
3518 extensions on linux targets.
3520 * New commands (for set/show, see "New options" below)
3522 catch syscall [NAME(S) | NUMBER(S)]
3523 Catch system calls. Arguments, which should be names of system
3524 calls or their numbers, mean catch only those syscalls. Without
3525 arguments, every syscall will be caught. When the inferior issues
3526 any of the specified syscalls, GDB will stop and announce the system
3527 call, both when it is called and when its call returns. This
3528 feature is currently available with a native GDB running on the
3529 Linux Kernel, under the following architectures: x86, x86_64,
3530 PowerPC and PowerPC64.
3532 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3534 Search memory for a sequence of bytes.
3536 maint set python print-stack
3537 maint show python print-stack
3538 Show a stack trace when an error is encountered in a Python script.
3541 Invoke CODE by passing it to the Python interpreter.
3546 These allow macros to be defined, undefined, and listed
3550 Show operating system information about processes.
3553 List the inferiors currently under GDB's control.
3556 Switch focus to inferior number NUM.
3559 Detach from inferior number NUM.
3562 Kill inferior number NUM.
3566 set spu stop-on-load
3567 show spu stop-on-load
3568 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3570 set spu auto-flush-cache
3571 show spu auto-flush-cache
3572 Control whether to automatically flush the software-managed cache
3573 during Cell/B.E. debugging.
3575 set sh calling-convention
3576 show sh calling-convention
3577 Control the calling convention used when calling SH target functions.
3580 show debug timestamp
3581 Control display of timestamps with GDB debugging output.
3583 set disassemble-next-line
3584 show disassemble-next-line
3585 Control display of disassembled source lines or instructions when
3588 set remote noack-packet
3589 show remote noack-packet
3590 Set/show the use of remote protocol QStartNoAckMode packet. See above
3591 under "New remote packets."
3593 set remote query-attached-packet
3594 show remote query-attached-packet
3595 Control use of remote protocol `qAttached' (query-attached) packet.
3597 set remote read-siginfo-object
3598 show remote read-siginfo-object
3599 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3602 set remote write-siginfo-object
3603 show remote write-siginfo-object
3604 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3607 set remote reverse-continue
3608 show remote reverse-continue
3609 Control use of remote protocol 'bc' (reverse-continue) packet.
3611 set remote reverse-step
3612 show remote reverse-step
3613 Control use of remote protocol 'bs' (reverse-step) packet.
3615 set displaced-stepping
3616 show displaced-stepping
3617 Control displaced stepping mode. Displaced stepping is a way to
3618 single-step over breakpoints without removing them from the debuggee.
3619 Also known as "out-of-line single-stepping".
3622 show debug displaced
3623 Control display of debugging info for displaced stepping.
3625 maint set internal-error
3626 maint show internal-error
3627 Control what GDB does when an internal error is detected.
3629 maint set internal-warning
3630 maint show internal-warning
3631 Control what GDB does when an internal warning is detected.
3636 Use a wrapper program to launch programs for debugging.
3638 set multiple-symbols (all|ask|cancel)
3639 show multiple-symbols
3640 The value of this variable can be changed to adjust the debugger behavior
3641 when an expression or a breakpoint location contains an ambiguous symbol
3642 name (an overloaded function name, for instance).
3644 set breakpoint always-inserted
3645 show breakpoint always-inserted
3646 Keep breakpoints always inserted in the target, as opposed to inserting
3647 them when resuming the target, and removing them when the target stops.
3648 This option can improve debugger performance on slow remote targets.
3650 set arm fallback-mode (arm|thumb|auto)
3651 show arm fallback-mode
3652 set arm force-mode (arm|thumb|auto)
3654 These commands control how ARM GDB determines whether instructions
3655 are ARM or Thumb. The default for both settings is auto, which uses
3656 the current CPSR value for instructions without symbols; previous
3657 versions of GDB behaved as if "set arm fallback-mode arm".
3659 set disable-randomization
3660 show disable-randomization
3661 Standalone programs run with the virtual address space randomization enabled
3662 by default on some platforms. This option keeps the addresses stable across
3663 multiple debugging sessions.
3667 Control whether other threads are stopped or not when some thread hits
3672 Requests that asynchronous execution is enabled in the target, if available.
3673 In this case, it's possible to resume target in the background, and interact
3674 with GDB while the target is running. "show target-async" displays the
3675 current state of asynchronous execution of the target.
3677 set target-wide-charset
3678 show target-wide-charset
3679 The target-wide-charset is the name of the character set that GDB
3680 uses when printing characters whose type is wchar_t.
3682 set tcp auto-retry (on|off)
3684 set tcp connect-timeout
3685 show tcp connect-timeout
3686 These commands allow GDB to retry failed TCP connections to a remote stub
3687 with a specified timeout period; this is useful if the stub is launched
3688 in parallel with GDB but may not be ready to accept connections immediately.
3690 set libthread-db-search-path
3691 show libthread-db-search-path
3692 Control list of directories which GDB will search for appropriate
3695 set schedule-multiple (on|off)
3696 show schedule-multiple
3697 Allow GDB to resume all threads of all processes or only threads of
3698 the current process.
3702 Use more aggressive caching for accesses to the stack. This improves
3703 performance of remote debugging (particularly backtraces) without
3704 affecting correctness.
3706 set interactive-mode (on|off|auto)
3707 show interactive-mode
3708 Control whether GDB runs in interactive mode (on) or not (off).
3709 When in interactive mode, GDB waits for the user to answer all
3710 queries. Otherwise, GDB does not wait and assumes the default
3711 answer. When set to auto (the default), GDB determines which
3712 mode to use based on the stdin settings.
3717 For program forks, this is replaced by the new more generic `info
3718 inferiors' command. To list checkpoints, you can still use the
3719 `info checkpoints' command, which was an alias for the `info forks'
3723 Replaced by the new `inferior' command. To switch between
3724 checkpoints, you can still use the `restart' command, which was an
3725 alias for the `fork' command.
3728 This is removed, since some targets don't have a notion of
3729 processes. To switch between processes, you can still use the
3730 `inferior' command using GDB's own inferior number.
3733 For program forks, this is replaced by the new more generic `kill
3734 inferior' command. To delete a checkpoint, you can still use the
3735 `delete checkpoint' command, which was an alias for the `delete
3739 For program forks, this is replaced by the new more generic `detach
3740 inferior' command. To detach a checkpoint, you can still use the
3741 `detach checkpoint' command, which was an alias for the `detach
3744 * New native configurations
3746 x86/x86_64 Darwin i[34567]86-*-darwin*
3748 x86_64 MinGW x86_64-*-mingw*
3752 Lattice Mico32 lm32-*
3753 x86 DICOS i[34567]86-*-dicos*
3754 x86_64 DICOS x86_64-*-dicos*
3757 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3758 (mingw32ce) debugging.
3764 These commands were actually not implemented on any target.
3766 *** Changes in GDB 6.8
3768 * New native configurations
3770 NetBSD/hppa hppa*-*netbsd*
3771 Xtensa GNU/Linux xtensa*-*-linux*
3775 NetBSD/hppa hppa*-*-netbsd*
3776 Xtensa GNU/Lunux xtensa*-*-linux*
3778 * Change in command line behavior -- corefiles vs. process ids.
3780 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3781 attaching to process NUMBER fails, GDB no longer attempts to open a
3782 core file named NUMBER. Attaching to a program using the -c option
3783 is no longer supported. Instead, use the '-p' or '--pid' options.
3785 * GDB can now be built as a native debugger for debugging Windows x86
3786 (mingw32) Portable Executable (PE) programs.
3788 * Pending breakpoints no longer change their number when their address
3791 * GDB now supports breakpoints with multiple locations,
3792 including breakpoints on C++ constructors, inside C++ templates,
3793 and in inlined functions.
3795 * GDB's ability to debug optimized code has been improved. GDB more
3796 accurately identifies function bodies and lexical blocks that occupy
3797 more than one contiguous range of addresses.
3799 * Target descriptions can now describe registers for PowerPC.
3801 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3802 registers on PowerPC targets.
3804 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3805 targets even when the libthread_db library is not available.
3807 * The GDB remote stub, gdbserver, now supports the new file transfer
3808 commands (remote put, remote get, and remote delete).
3810 * The GDB remote stub, gdbserver, now supports run and attach in
3811 extended-remote mode.
3813 * hppa*64*-*-hpux11* target broken
3814 The debugger is unable to start a program and fails with the following
3815 error: "Error trying to get information about dynamic linker".
3816 The gdb-6.7 release is also affected.
3818 * GDB now supports the --enable-targets= configure option to allow
3819 building a single GDB executable that supports multiple remote
3820 target architectures.
3822 * GDB now supports debugging C and C++ programs which use the
3823 Decimal Floating Point extension. In addition, the PowerPC target
3824 now has a set of pseudo-registers to inspect decimal float values
3825 stored in two consecutive float registers.
3827 * The -break-insert MI command can optionally create pending
3830 * Improved support for debugging Ada
3831 Many improvements to the Ada language support have been made. These
3833 - Better support for Ada2005 interface types
3834 - Improved handling of arrays and slices in general
3835 - Better support for Taft-amendment types
3836 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3838 - Improved command completion in Ada
3841 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3846 set print frame-arguments (all|scalars|none)
3847 show print frame-arguments
3848 The value of this variable can be changed to control which argument
3849 values should be printed by the debugger when displaying a frame.
3854 Transfer files to and from a remote target, and delete remote files.
3861 Transfer files to and from a remote target, and delete remote files.
3863 * New remote packets
3870 Open, close, read, write, and delete files on the remote system.
3873 Attach to an existing process on the remote system, in extended-remote
3877 Run a new process on the remote system, in extended-remote mode.
3879 *** Changes in GDB 6.7
3881 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3882 bfd, libiberty and opcodes, as revealed by static analysis donated by
3883 Coverity, Inc. (http://scan.coverity.com).
3885 * When looking up multiply-defined global symbols, GDB will now prefer the
3886 symbol definition in the current shared library if it was built using the
3887 -Bsymbolic linker option.
3889 * When the Text User Interface (TUI) is not configured, GDB will now
3890 recognize the -tui command-line option and print a message that the TUI
3893 * The GDB remote stub, gdbserver, now has lower overhead for high
3894 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3896 * GDB for MIPS targets now autodetects whether a remote target provides
3897 32-bit or 64-bit register values.
3899 * Support for C++ member pointers has been improved.
3901 * GDB now understands XML target descriptions, which specify the
3902 target's overall architecture. GDB can read a description from
3903 a local file or over the remote serial protocol.
3905 * Vectors of single-byte data use a new integer type which is not
3906 automatically displayed as character or string data.
3908 * The /s format now works with the print command. It displays
3909 arrays of single-byte integers and pointers to single-byte integers
3912 * Target descriptions can now describe target-specific registers,
3913 for architectures which have implemented the support (currently
3914 only ARM, M68K, and MIPS).
3916 * GDB and the GDB remote stub, gdbserver, now support the XScale
3919 * The GDB remote stub, gdbserver, has been updated to support
3920 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3921 has been rewritten to use the standard GDB remote protocol.
3923 * GDB can now step into C++ functions which are called through thunks.
3925 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3927 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3928 layout. It also supports a TextSeg= and DataSeg= response when only
3929 segment base addresses (rather than offsets) are available.
3931 * The /i format now outputs any trailing branch delay slot instructions
3932 immediately following the last instruction within the count specified.
3934 * The GDB remote protocol "T" stop reply packet now supports a
3935 "library" response. Combined with the new "qXfer:libraries:read"
3936 packet, this response allows GDB to debug shared libraries on targets
3937 where the operating system manages the list of loaded libraries (e.g.
3938 Windows and SymbianOS).
3940 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3941 (DLLs) on Windows and Windows CE targets.
3943 * GDB now supports a faster verification that a .debug file matches its binary
3944 according to its build-id signature, if the signature is present.
3950 Enable or disable hardware flow control (RTS/CTS) on the serial port
3951 when debugging using remote targets.
3953 set mem inaccessible-by-default
3954 show mem inaccessible-by-default
3955 If the target supplies a memory map, for instance via the remote
3956 protocol's "qXfer:memory-map:read" packet, setting this variable
3957 prevents GDB from accessing memory outside the memory map. This
3958 is useful for targets with memory mapped registers or which react
3959 badly to accesses of unmapped address space.
3961 set breakpoint auto-hw
3962 show breakpoint auto-hw
3963 If the target supplies a memory map, for instance via the remote
3964 protocol's "qXfer:memory-map:read" packet, setting this variable
3965 lets GDB use hardware breakpoints automatically for memory regions
3966 where it can not use software breakpoints. This covers both the
3967 "break" command and internal breakpoints used for other commands
3968 including "next" and "finish".
3971 catch exception unhandled
3972 Stop the program execution when Ada exceptions are raised.
3975 Stop the program execution when an Ada assertion failed.
3979 Set an alternate system root for target files. This is a more
3980 general version of "set solib-absolute-prefix", which is now
3981 an alias to "set sysroot".
3984 Provide extended SPU facility status information. This set of
3985 commands is available only when debugging the Cell/B.E. SPU
3988 * New native configurations
3990 OpenBSD/sh sh*-*openbsd*
3993 unset tdesc filename
3995 Use the specified local file as an XML target description, and do
3996 not query the target for its built-in description.
4000 OpenBSD/sh sh*-*-openbsd*
4001 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4002 Toshiba Media Processor mep-elf
4004 * New remote packets
4007 Ignore the specified signals; pass them directly to the debugged program
4008 without stopping other threads or reporting them to GDB.
4010 qXfer:features:read:
4011 Read an XML target description from the target, which describes its
4016 Read or write contents of an spufs file on the target system. These
4017 packets are available only on the Cell/B.E. SPU architecture.
4019 qXfer:libraries:read:
4020 Report the loaded shared libraries. Combined with new "T" packet
4021 response, this packet allows GDB to debug shared libraries on
4022 targets where the operating system manages the list of loaded
4023 libraries (e.g. Windows and SymbianOS).
4027 Support for these obsolete configurations has been removed.
4035 i[34567]86-*-lynxos*
4036 i[34567]86-*-netware*
4037 i[34567]86-*-sco3.2v5*
4038 i[34567]86-*-sco3.2v4*
4040 i[34567]86-*-sysv4.2*
4043 i[34567]86-*-unixware2*
4044 i[34567]86-*-unixware*
4053 * Other removed features
4060 Various m68k-only ROM monitors.
4067 Various Renesas ROM monitors and debugging interfaces for SH and
4072 Support for a Macraigor serial interface to on-chip debugging.
4073 GDB does not directly support the newer parallel or USB
4078 A debug information format. The predecessor to DWARF 2 and
4079 DWARF 3, which are still supported.
4081 Support for the HP aCC compiler on HP-UX/PA-RISC
4083 SOM-encapsulated symbolic debugging information, automatic
4084 invocation of pxdb, and the aCC custom C++ ABI. This does not
4085 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4086 with aCC can still be debugged on an assembly level.
4088 MIPS ".pdr" sections
4090 A MIPS-specific format used to describe stack frame layout
4091 in debugging information.
4095 GDB could work with an older version of Guile to debug
4096 the interpreter and Scheme programs running in it.
4098 set mips stack-arg-size
4099 set mips saved-gpreg-size
4101 Use "set mips abi" to control parameter passing for MIPS.
4103 *** Changes in GDB 6.6
4108 Cell Broadband Engine SPU spu-elf
4110 * GDB can now be configured as a cross-debugger targeting native Windows
4111 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4112 running on a Windows system over TCP/IP to debug Windows programs.
4114 * The GDB remote stub, gdbserver, has been updated to support Windows and
4115 Cygwin debugging. Both single-threaded and multi-threaded programs are
4118 * The "set trust-readonly-sections" command works again. This command was
4119 broken in GDB 6.3, 6.4, and 6.5.
4121 * The "load" command now supports writing to flash memory, if the remote
4122 stub provides the required support.
4124 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4125 longer requires symbolic debug information (e.g. DWARF-2).
4130 unset substitute-path
4131 show substitute-path
4132 Manage a list of substitution rules that GDB uses to rewrite the name
4133 of the directories where the sources are located. This can be useful
4134 for instance when the sources were moved to a different location
4135 between compilation and debugging.
4139 Print each CLI command as it is executed. Each command is prefixed with
4140 a number of `+' symbols representing the nesting depth.
4141 The source command now has a `-v' option to enable the same feature.
4145 The ARM Demon monitor support (RDP protocol, "target rdp").
4147 Kernel Object Display, an embedded debugging feature which only worked with
4148 an obsolete version of Cisco IOS.
4150 The 'set download-write-size' and 'show download-write-size' commands.
4152 * New remote packets
4155 Tell a stub about GDB client features, and request remote target features.
4156 The first feature implemented is PacketSize, which allows the target to
4157 specify the size of packets it can handle - to minimize the number of
4158 packets required and improve performance when connected to a remote
4162 Fetch an OS auxilliary vector from the remote stub. This packet is a
4163 more efficient replacement for qPart:auxv:read.
4165 qXfer:memory-map:read:
4166 Fetch a memory map from the remote stub, including information about
4167 RAM, ROM, and flash memory devices.
4172 Erase and program a flash memory device.
4174 * Removed remote packets
4177 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4178 used it, and only gdbserver implemented it.
4180 *** Changes in GDB 6.5
4184 Renesas M32C/M16C m32c-elf
4186 Morpho Technologies ms1 ms1-elf
4190 init-if-undefined Initialize a convenience variable, but
4191 only if it doesn't already have a value.
4193 The following commands are presently only implemented for native GNU/Linux:
4195 checkpoint Save a snapshot of the program state.
4197 restart <n> Return the program state to a
4198 previously saved state.
4200 info checkpoints List currently saved checkpoints.
4202 delete-checkpoint <n> Delete a previously saved checkpoint.
4204 set|show detach-on-fork Tell gdb whether to detach from a newly
4205 forked process, or to keep debugging it.
4207 info forks List forks of the user program that
4208 are available to be debugged.
4210 fork <n> Switch to debugging one of several
4211 forks of the user program that are
4212 available to be debugged.
4214 delete-fork <n> Delete a fork from the list of forks
4215 that are available to be debugged (and
4216 kill the forked process).
4218 detach-fork <n> Delete a fork from the list of forks
4219 that are available to be debugged (and
4220 allow the process to continue).
4224 Morpho Technologies ms2 ms1-elf
4226 * Improved Windows host support
4228 GDB now builds as a cross debugger hosted on i686-mingw32, including
4229 native console support, and remote communications using either
4230 network sockets or serial ports.
4232 * Improved Modula-2 language support
4234 GDB can now print most types in the Modula-2 syntax. This includes:
4235 basic types, set types, record types, enumerated types, range types,
4236 pointer types and ARRAY types. Procedure var parameters are correctly
4237 printed and hexadecimal addresses and character constants are also
4238 written in the Modula-2 syntax. Best results can be obtained by using
4239 GNU Modula-2 together with the -gdwarf-2 command line option.
4243 The ARM rdi-share module.
4245 The Netware NLM debug server.
4247 *** Changes in GDB 6.4
4249 * New native configurations
4251 OpenBSD/arm arm*-*-openbsd*
4252 OpenBSD/mips64 mips64-*-openbsd*
4256 Morpho Technologies ms1 ms1-elf
4258 * New command line options
4260 --batch-silent As for --batch, but totally silent.
4261 --return-child-result The debugger will exist with the same value
4262 the child (debugged) program exited with.
4263 --eval-command COMMAND, -ex COMMAND
4264 Execute a single GDB CLI command. This may be
4265 specified multiple times and in conjunction
4266 with the --command (-x) option.
4268 * Deprecated commands removed
4270 The following commands, that were deprecated in 2000, have been
4274 set|show arm disassembly-flavor set|show arm disassembler
4275 othernames set arm disassembler
4276 set|show remotedebug set|show debug remote
4277 set|show archdebug set|show debug arch
4278 set|show eventdebug set|show debug event
4281 * New BSD user-level threads support
4283 It is now possible to debug programs using the user-level threads
4284 library on OpenBSD and FreeBSD. Currently supported (target)
4287 FreeBSD/amd64 x86_64-*-freebsd*
4288 FreeBSD/i386 i386-*-freebsd*
4289 OpenBSD/i386 i386-*-openbsd*
4291 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4292 are not yet supported.
4294 * New support for Matsushita MN10300 w/sim added
4295 (Work in progress). mn10300-elf.
4297 * REMOVED configurations and files
4299 VxWorks and the XDR protocol *-*-vxworks
4300 Motorola MCORE mcore-*-*
4301 National Semiconductor NS32000 ns32k-*-*
4303 * New "set print array-indexes" command
4305 After turning this setting "on", GDB prints the index of each element
4306 when displaying arrays. The default is "off" to preserve the previous
4309 * VAX floating point support
4311 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4313 * User-defined command support
4315 In addition to using $arg0..$arg9 for argument passing, it is now possible
4316 to use $argc to determine now many arguments have been passed. See the
4317 section on user-defined commands in the user manual for more information.
4319 *** Changes in GDB 6.3:
4321 * New command line option
4323 GDB now accepts -l followed by a number to set the timeout for remote
4326 * GDB works with GCC -feliminate-dwarf2-dups
4328 GDB now supports a more compact representation of DWARF-2 debug
4329 information using DW_FORM_ref_addr references. These are produced
4330 by GCC with the option -feliminate-dwarf2-dups and also by some
4331 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4332 to use -feliminate-dwarf2-dups.
4334 * Internationalization
4336 When supported by the host system, GDB will be built with
4337 internationalization (libintl). The task of marking up the sources is
4338 continued, we're looking forward to our first translation.
4342 Initial support for debugging programs compiled with the GNAT
4343 implementation of the Ada programming language has been integrated
4344 into GDB. In this release, support is limited to expression evaluation.
4346 * New native configurations
4348 GNU/Linux/m32r m32r-*-linux-gnu
4352 GDB's remote protocol now includes support for the 'p' packet. This
4353 packet is used to fetch individual registers from a remote inferior.
4355 * END-OF-LIFE registers[] compatibility module
4357 GDB's internal register infrastructure has been completely rewritten.
4358 The new infrastructure making possible the implementation of key new
4359 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4362 GDB 6.3 will be the last release to include the the registers[]
4363 compatibility module that allowed out-of-date configurations to
4364 continue to work. This change directly impacts the following
4374 powerpc bdm protocol
4376 Unless there is activity to revive these configurations, they will be
4377 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4379 * OBSOLETE configurations and files
4381 Configurations that have been declared obsolete in this release have
4382 been commented out. Unless there is activity to revive these
4383 configurations, the next release of GDB will have their sources
4384 permanently REMOVED.
4393 *** Changes in GDB 6.2.1:
4395 * MIPS `break main; run' gave an heuristic-fence-post warning
4397 When attempting to run even a simple program, a warning about
4398 heuristic-fence-post being hit would be reported. This problem has
4401 * MIPS IRIX 'long double' crashed GDB
4403 When examining a long double variable, GDB would get a segmentation
4404 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4405 IRIX long double values).
4409 A bug in the VAX stack code was causing problems with the "next"
4410 command. This problem has been fixed.
4412 *** Changes in GDB 6.2:
4414 * Fix for ``many threads''
4416 On GNU/Linux systems that use the NPTL threads library, a program
4417 rapidly creating and deleting threads would confuse GDB leading to the
4420 ptrace: No such process.
4421 thread_db_get_info: cannot get thread info: generic error
4423 This problem has been fixed.
4425 * "-async" and "-noasync" options removed.
4427 Support for the broken "-noasync" option has been removed (it caused
4430 * New ``start'' command.
4432 This command runs the program until the begining of the main procedure.
4434 * New BSD Kernel Data Access Library (libkvm) interface
4436 Using ``target kvm'' it is now possible to debug kernel core dumps and
4437 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4438 platforms. Currently supported (native-only) configurations are:
4440 FreeBSD/amd64 x86_64-*-freebsd*
4441 FreeBSD/i386 i?86-*-freebsd*
4442 NetBSD/i386 i?86-*-netbsd*
4443 NetBSD/m68k m68*-*-netbsd*
4444 NetBSD/sparc sparc-*-netbsd*
4445 OpenBSD/amd64 x86_64-*-openbsd*
4446 OpenBSD/i386 i?86-*-openbsd*
4447 OpenBSD/m68k m68*-openbsd*
4448 OpenBSD/sparc sparc-*-openbsd*
4450 * Signal trampoline code overhauled
4452 Many generic problems with GDB's signal handling code have been fixed.
4453 These include: backtraces through non-contiguous stacks; recognition
4454 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4455 call; backtrace through a signal trampoline; step into and out of
4456 signal handlers; and single-stepping in the signal trampoline.
4458 Please note that kernel bugs are a limiting factor here. These
4459 features have been shown to work on an s390 GNU/Linux system that
4460 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4462 * Cygwin support for DWARF 2 added.
4464 * New native configurations
4466 GNU/Linux/hppa hppa*-*-linux*
4467 OpenBSD/hppa hppa*-*-openbsd*
4468 OpenBSD/m68k m68*-*-openbsd*
4469 OpenBSD/m88k m88*-*-openbsd*
4470 OpenBSD/powerpc powerpc-*-openbsd*
4471 NetBSD/vax vax-*-netbsd*
4472 OpenBSD/vax vax-*-openbsd*
4474 * END-OF-LIFE frame compatibility module
4476 GDB's internal frame infrastructure has been completely rewritten.
4477 The new infrastructure making it possible to support key new features
4478 including DWARF 2 Call Frame Information. To aid in the task of
4479 migrating old configurations to this new infrastructure, a
4480 compatibility module, that allowed old configurations to continue to
4481 work, was also included.
4483 GDB 6.2 will be the last release to include this frame compatibility
4484 module. This change directly impacts the following configurations:
4494 Unless there is activity to revive these configurations, they will be
4495 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4497 * REMOVED configurations and files
4499 Sun 3, running SunOS 3 m68*-*-sunos3*
4500 Sun 3, running SunOS 4 m68*-*-sunos4*
4501 Sun 2, running SunOS 3 m68000-*-sunos3*
4502 Sun 2, running SunOS 4 m68000-*-sunos4*
4503 Motorola 680x0 running LynxOS m68*-*-lynxos*
4504 AT&T 3b1/Unix pc m68*-att-*
4505 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4506 decstation mips-dec-* mips-little-*
4507 riscos mips-*-riscos* mips-*-sysv*
4508 sonymips mips-sony-*
4509 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4511 *** Changes in GDB 6.1.1:
4513 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4515 The TUI (Text-mode User Interface) is now built as part of a default
4516 GDB configuration. It is enabled by either selecting the TUI with the
4517 command line option "-i=tui" or by running the separate "gdbtui"
4518 program. For more information on the TUI, see the manual "Debugging
4521 * Pending breakpoint support (also included in GDB 6.1)
4523 Support has been added to allow you to specify breakpoints in shared
4524 libraries that have not yet been loaded. If a breakpoint location
4525 cannot be found, and the "breakpoint pending" option is set to auto,
4526 GDB queries you if you wish to make the breakpoint pending on a future
4527 shared-library load. If and when GDB resolves the breakpoint symbol,
4528 the pending breakpoint is removed as one or more regular breakpoints
4531 Pending breakpoints are very useful for GCJ Java debugging.
4533 * Fixed ISO-C build problems
4535 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4536 non ISO-C code that stopped them being built using a more strict ISO-C
4537 compiler (e.g., IBM's C compiler).
4539 * Fixed build problem on IRIX 5
4541 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4542 wasn't able to compile compile on an IRIX 5 system.
4544 * Added execute permission to gdb/gdbserver/configure
4546 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4547 permission. This bug would cause configure to fail on a number of
4548 systems (Solaris, IRIX). Ref: server/519.
4550 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4552 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4553 has been updated to use constant array sizes.
4555 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4557 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4558 its generated DWARF Call Frame Info. This encoding was causing GDB to
4559 panic, that panic has been fixed. Ref: gdb/1628.
4561 * Fixed a problem when examining parameters in shared library code.
4563 When examining parameters in optimized shared library code generated
4564 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4565 not available''. GDB now correctly displays the variable's value.
4567 *** Changes in GDB 6.1:
4569 * Removed --with-mmalloc
4571 Support for the mmalloc memory manager has been removed, as it
4572 conflicted with the internal gdb byte cache.
4574 * Changes in AMD64 configurations
4576 The AMD64 target now includes the %cs and %ss registers. As a result
4577 the AMD64 remote protocol has changed; this affects the floating-point
4578 and SSE registers. If you rely on those registers for your debugging,
4579 you should upgrade gdbserver on the remote side.
4581 * Revised SPARC target
4583 The SPARC target has been completely revised, incorporating the
4584 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4585 support for LynxOS and SunOS 4 has been dropped. Calling functions
4586 from within GDB on operating systems with a non-executable stack
4587 (Solaris, OpenBSD) now works.
4591 GDB has a new C++ demangler which does a better job on the mangled
4592 names generated by current versions of g++. It also runs faster, so
4593 with this and other changes gdb should now start faster on large C++
4596 * DWARF 2 Location Expressions
4598 GDB support for location expressions has been extended to support function
4599 arguments and frame bases. Older versions of GDB could crash when they
4602 * C++ nested types and namespaces
4604 GDB's support for nested types and namespaces in C++ has been
4605 improved, especially if you use the DWARF 2 debugging format. (This
4606 is the default for recent versions of GCC on most platforms.)
4607 Specifically, if you have a class "Inner" defined within a class or
4608 namespace "Outer", then GDB realizes that the class's name is
4609 "Outer::Inner", not simply "Inner". This should greatly reduce the
4610 frequency of complaints about not finding RTTI symbols. In addition,
4611 if you are stopped at inside of a function defined within a namespace,
4612 GDB modifies its name lookup accordingly.
4614 * New native configurations
4616 NetBSD/amd64 x86_64-*-netbsd*
4617 OpenBSD/amd64 x86_64-*-openbsd*
4618 OpenBSD/alpha alpha*-*-openbsd*
4619 OpenBSD/sparc sparc-*-openbsd*
4620 OpenBSD/sparc64 sparc64-*-openbsd*
4622 * New debugging protocols
4624 M32R with SDI protocol m32r-*-elf*
4626 * "set prompt-escape-char" command deleted.
4628 The command "set prompt-escape-char" has been deleted. This command,
4629 and its very obscure effet on GDB's prompt, was never documented,
4630 tested, nor mentioned in the NEWS file.
4632 * OBSOLETE configurations and files
4634 Configurations that have been declared obsolete in this release have
4635 been commented out. Unless there is activity to revive these
4636 configurations, the next release of GDB will have their sources
4637 permanently REMOVED.
4639 Sun 3, running SunOS 3 m68*-*-sunos3*
4640 Sun 3, running SunOS 4 m68*-*-sunos4*
4641 Sun 2, running SunOS 3 m68000-*-sunos3*
4642 Sun 2, running SunOS 4 m68000-*-sunos4*
4643 Motorola 680x0 running LynxOS m68*-*-lynxos*
4644 AT&T 3b1/Unix pc m68*-att-*
4645 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4646 decstation mips-dec-* mips-little-*
4647 riscos mips-*-riscos* mips-*-sysv*
4648 sonymips mips-sony-*
4649 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4651 * REMOVED configurations and files
4653 SGI Irix-4.x mips-sgi-irix4 or iris4
4654 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4655 Z8000 simulator z8k-zilog-none or z8ksim
4656 Matsushita MN10200 w/simulator mn10200-*-*
4657 H8/500 simulator h8500-hitachi-hms or h8500hms
4658 HP/PA running BSD hppa*-*-bsd*
4659 HP/PA running OSF/1 hppa*-*-osf*
4660 HP/PA Pro target hppa*-*-pro*
4661 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4662 386BSD i[3456]86-*-bsd*
4663 Sequent family i[3456]86-sequent-sysv4*
4664 i[3456]86-sequent-sysv*
4665 i[3456]86-sequent-bsd*
4666 SPARC running LynxOS sparc-*-lynxos*
4667 SPARC running SunOS 4 sparc-*-sunos4*
4668 Tsqware Sparclet sparclet-*-*
4669 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4671 *** Changes in GDB 6.0:
4675 Support for debugging the Objective-C programming language has been
4676 integrated into GDB.
4678 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4680 DWARF 2's Call Frame Information makes available compiler generated
4681 information that more exactly describes the program's run-time stack.
4682 By using this information, GDB is able to provide more robust stack
4685 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4686 have been updated to use a new backtrace mechanism which includes
4687 DWARF 2 CFI support.
4691 GDB's remote protocol has been extended to include support for hosted
4692 file I/O (where the remote target uses GDB's file system). See GDB's
4693 remote protocol documentation for details.
4695 * All targets using the new architecture framework.
4697 All of GDB's targets have been updated to use the new internal
4698 architecture framework. The way is now open for future GDB releases
4699 to include cross-architecture native debugging support (i386 on amd64,
4702 * GNU/Linux's Thread Local Storage (TLS)
4704 GDB now includes support for for the GNU/Linux implementation of
4705 per-thread variables.
4707 * GNU/Linux's Native POSIX Thread Library (NPTL)
4709 GDB's thread code has been updated to work with either the new
4710 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4712 * Separate debug info.
4714 GDB, in conjunction with BINUTILS, now supports a mechanism for
4715 automatically loading debug information from a separate file. Instead
4716 of shipping full debug and non-debug versions of system libraries,
4717 system integrators can now instead ship just the stripped libraries
4718 and optional debug files.
4720 * DWARF 2 Location Expressions
4722 DWARF 2 Location Expressions allow the compiler to more completely
4723 describe the location of variables (even in optimized code) to the
4726 GDB now includes preliminary support for location expressions (support
4727 for DW_OP_piece is still missing).
4731 A number of long standing bugs that caused GDB to die while starting a
4732 Java application have been fixed. GDB's Java support is now
4733 considered "useable".
4735 * GNU/Linux support for fork, vfork, and exec.
4737 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4738 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4741 * GDB supports logging output to a file
4743 There are two new commands, "set logging" and "show logging", which can be
4744 used to capture GDB's output to a file.
4746 * The meaning of "detach" has changed for gdbserver
4748 The "detach" command will now resume the application, as documented. To
4749 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4752 * d10v, m68hc11 `regs' command deprecated
4754 The `info registers' command has been updated so that it displays the
4755 registers using a format identical to the old `regs' command.
4759 A new command, "maint set profile on/off", has been added. This command can
4760 be used to enable or disable profiling while running GDB, to profile a
4761 session or a set of commands. In addition there is a new configure switch,
4762 "--enable-profiling", which will cause GDB to be compiled with profiling
4763 data, for more informative profiling results.
4765 * Default MI syntax changed to "mi2".
4767 The default MI (machine interface) syntax, enabled by the command line
4768 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4769 "mi1", can be enabled by specifying the option "-i=mi1".
4771 Support for the original "mi0" syntax (included in GDB 5.0) has been
4774 Fix for gdb/192: removed extraneous space when displaying frame level.
4775 Fix for gdb/672: update changelist is now output in mi list format.
4776 Fix for gdb/702: a -var-assign that updates the value now shows up
4777 in a subsequent -var-update.
4779 * New native configurations.
4781 FreeBSD/amd64 x86_64-*-freebsd*
4783 * Multi-arched targets.
4785 HP/PA HPUX11 hppa*-*-hpux*
4786 Renesas M32R/D w/simulator m32r-*-elf*
4788 * OBSOLETE configurations and files
4790 Configurations that have been declared obsolete in this release have
4791 been commented out. Unless there is activity to revive these
4792 configurations, the next release of GDB will have their sources
4793 permanently REMOVED.
4795 Z8000 simulator z8k-zilog-none or z8ksim
4796 Matsushita MN10200 w/simulator mn10200-*-*
4797 H8/500 simulator h8500-hitachi-hms or h8500hms
4798 HP/PA running BSD hppa*-*-bsd*
4799 HP/PA running OSF/1 hppa*-*-osf*
4800 HP/PA Pro target hppa*-*-pro*
4801 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4802 Sequent family i[3456]86-sequent-sysv4*
4803 i[3456]86-sequent-sysv*
4804 i[3456]86-sequent-bsd*
4805 Tsqware Sparclet sparclet-*-*
4806 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4808 * REMOVED configurations and files
4811 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4812 IBM AIX PS/2 i[3456]86-*-aix
4813 i386 running Mach 3.0 i[3456]86-*-mach3*
4814 i386 running Mach i[3456]86-*-mach*
4815 i386 running OSF/1 i[3456]86-*osf1mk*
4816 HP/Apollo 68k Family m68*-apollo*-sysv*,
4818 m68*-hp-bsd*, m68*-hp-hpux*
4819 Argonaut Risc Chip (ARC) arc-*-*
4820 Mitsubishi D30V d30v-*-*
4821 Fujitsu FR30 fr30-*-elf*
4822 OS/9000 i[34]86-*-os9k
4823 I960 with MON960 i960-*-coff
4825 * MIPS $fp behavior changed
4827 The convenience variable $fp, for the MIPS, now consistently returns
4828 the address of the current frame's base. Previously, depending on the
4829 context, $fp could refer to either $sp or the current frame's base
4830 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4831 The GNU Source-Level Debugger''.
4833 *** Changes in GDB 5.3:
4835 * GNU/Linux shared library multi-threaded performance improved.
4837 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4838 `/proc', in preference to `ptrace' for memory reads. This may result
4839 in an improvement in the start-up time of multi-threaded, shared
4840 library applications when run under GDB. One GDB user writes: ``loads
4841 shared libs like mad''.
4843 * ``gdbserver'' now supports multi-threaded applications on some targets
4845 Support for debugging multi-threaded applications which use
4846 the GNU/Linux LinuxThreads package has been added for
4847 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4848 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4850 * GDB now supports C/C++ preprocessor macros.
4852 GDB now expands preprocessor macro invocations in C/C++ expressions,
4853 and provides various commands for showing macro definitions and how
4856 The new command `macro expand EXPRESSION' expands any macro
4857 invocations in expression, and shows the result.
4859 The new command `show macro MACRO-NAME' shows the definition of the
4860 macro named MACRO-NAME, and where it was defined.
4862 Most compilers don't include information about macros in the debugging
4863 information by default. In GCC 3.1, for example, you need to compile
4864 your program with the options `-gdwarf-2 -g3'. If the macro
4865 information is present in the executable, GDB will read it.
4867 * Multi-arched targets.
4869 DEC Alpha (partial) alpha*-*-*
4870 DEC VAX (partial) vax-*-*
4872 National Semiconductor NS32000 (partial) ns32k-*-*
4873 Motorola 68000 (partial) m68k-*-*
4874 Motorola MCORE mcore-*-*
4878 Fujitsu FRV architecture added by Red Hat frv*-*-*
4881 * New native configurations
4883 Alpha NetBSD alpha*-*-netbsd*
4884 SH NetBSD sh*-*-netbsdelf*
4885 MIPS NetBSD mips*-*-netbsd*
4886 UltraSPARC NetBSD sparc64-*-netbsd*
4888 * OBSOLETE configurations and files
4890 Configurations that have been declared obsolete in this release have
4891 been commented out. Unless there is activity to revive these
4892 configurations, the next release of GDB will have their sources
4893 permanently REMOVED.
4895 Mitsubishi D30V d30v-*-*
4896 OS/9000 i[34]86-*-os9k
4897 IBM AIX PS/2 i[3456]86-*-aix
4898 Fujitsu FR30 fr30-*-elf*
4899 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4900 Argonaut Risc Chip (ARC) arc-*-*
4901 i386 running Mach 3.0 i[3456]86-*-mach3*
4902 i386 running Mach i[3456]86-*-mach*
4903 i386 running OSF/1 i[3456]86-*osf1mk*
4904 HP/Apollo 68k Family m68*-apollo*-sysv*,
4906 m68*-hp-bsd*, m68*-hp-hpux*
4907 I960 with MON960 i960-*-coff
4909 * OBSOLETE languages
4911 CHILL, a Pascal like language used by telecommunications companies.
4913 * REMOVED configurations and files
4915 AMD 29k family via UDI a29k-amd-udi, udi29k
4916 A29K VxWorks a29k-*-vxworks
4917 AMD 29000 embedded, using EBMON a29k-none-none
4918 AMD 29000 embedded with COFF a29k-none-coff
4919 AMD 29000 embedded with a.out a29k-none-aout
4921 testsuite/gdb.hp/gdb.threads-hp/ directory
4923 * New command "set max-user-call-depth <nnn>"
4925 This command allows the user to limit the call depth of user-defined
4926 commands. The default is 1024.
4928 * Changes in FreeBSD/i386 native debugging.
4930 Support for the "generate-core-file" has been added.
4932 * New commands "dump", "append", and "restore".
4934 These commands allow data to be copied from target memory
4935 to a bfd-format or binary file (dump and append), and back
4936 from a file into memory (restore).
4938 * Improved "next/step" support on multi-processor Alpha Tru64.
4940 The previous single-step mechanism could cause unpredictable problems,
4941 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4942 of a software single-step mechanism prevents this.
4944 *** Changes in GDB 5.2.1:
4952 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4953 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4954 Fix, by Joel Brobecker imported from mainline.
4956 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4957 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4958 Fix, by Fred Fish, imported from mainline.
4960 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4961 Surprisingly enough, it works now.
4962 By Michal Ludvig, imported from mainline.
4964 i386 hardware watchpoint support:
4965 avoid misses on second run for some targets.
4966 By Pierre Muller, imported from mainline.
4968 *** Changes in GDB 5.2:
4970 * New command "set trust-readonly-sections on[off]".
4972 This command is a hint that tells gdb that read-only sections
4973 really are read-only (ie. that their contents will not change).
4974 In this mode, gdb will go to the object file rather than the
4975 target to read memory from read-only sections (such as ".text").
4976 This can be a significant performance improvement on some
4977 (notably embedded) targets.
4979 * New command "generate-core-file" (or "gcore").
4981 This new gdb command allows the user to drop a core file of the child
4982 process state at any time. So far it's been implemented only for
4983 GNU/Linux and Solaris, but should be relatively easily ported to other
4984 hosts. Argument is core file name (defaults to core.<pid>).
4986 * New command line option
4988 GDB now accepts --pid or -p followed by a process id.
4990 * Change in command line behavior -- corefiles vs. process ids.
4992 There is a subtle behavior in the way in which GDB handles
4993 command line arguments. The first non-flag argument is always
4994 a program to debug, but the second non-flag argument may either
4995 be a corefile or a process id. Previously, GDB would attempt to
4996 open the second argument as a corefile, and if that failed, would
4997 issue a superfluous error message and then attempt to attach it as
4998 a process. Now, if the second argument begins with a non-digit,
4999 it will be treated as a corefile. If it begins with a digit,
5000 GDB will attempt to attach it as a process, and if no such process
5001 is found, will then attempt to open it as a corefile.
5003 * Changes in ARM configurations.
5005 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5006 configuration is fully multi-arch.
5008 * New native configurations
5010 ARM NetBSD arm*-*-netbsd*
5011 x86 OpenBSD i[3456]86-*-openbsd*
5012 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5013 Sparc64 running FreeBSD sparc64-*-freebsd*
5017 Sanyo XStormy16 xstormy16-elf
5019 * OBSOLETE configurations and files
5021 Configurations that have been declared obsolete in this release have
5022 been commented out. Unless there is activity to revive these
5023 configurations, the next release of GDB will have their sources
5024 permanently REMOVED.
5026 AMD 29k family via UDI a29k-amd-udi, udi29k
5027 A29K VxWorks a29k-*-vxworks
5028 AMD 29000 embedded, using EBMON a29k-none-none
5029 AMD 29000 embedded with COFF a29k-none-coff
5030 AMD 29000 embedded with a.out a29k-none-aout
5032 testsuite/gdb.hp/gdb.threads-hp/ directory
5034 * REMOVED configurations and files
5036 TI TMS320C80 tic80-*-*
5038 PowerPC Solaris powerpcle-*-solaris*
5039 PowerPC Windows NT powerpcle-*-cygwin32
5040 PowerPC Netware powerpc-*-netware*
5041 Harris/CXUX m88k m88*-harris-cxux*
5042 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5043 ns32k-utek-sysv* ns32k-utek-*
5044 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5045 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5046 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5047 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5048 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5050 * Changes to command line processing
5052 The new `--args' feature can be used to specify command-line arguments
5053 for the inferior from gdb's command line.
5055 * Changes to key bindings
5057 There is a new `operate-and-get-next' function bound to `C-o'.
5059 *** Changes in GDB 5.1.1
5061 Fix compile problem on DJGPP.
5063 Fix a problem with floating-point registers on the i386 being
5066 Fix to stop GDB crashing on .debug_str debug info.
5068 Numerous documentation fixes.
5070 Numerous testsuite fixes.
5072 *** Changes in GDB 5.1:
5074 * New native configurations
5076 Alpha FreeBSD alpha*-*-freebsd*
5077 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5078 MIPS GNU/Linux mips*-*-linux*
5079 MIPS SGI Irix 6.x mips*-sgi-irix6*
5080 ia64 AIX ia64-*-aix*
5081 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5085 Motorola 68HC11 and 68HC12 m68hc11-elf
5087 UltraSparc running GNU/Linux sparc64-*-linux*
5089 * OBSOLETE configurations and files
5091 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5092 Harris/CXUX m88k m88*-harris-cxux*
5093 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5094 ns32k-utek-sysv* ns32k-utek-*
5095 TI TMS320C80 tic80-*-*
5097 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5098 PowerPC Solaris powerpcle-*-solaris*
5099 PowerPC Windows NT powerpcle-*-cygwin32
5100 PowerPC Netware powerpc-*-netware*
5101 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5102 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5103 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5104 Apple Macintosh (MPW) host N/A
5106 stuff.c (Program to stuff files into a specially prepared space in kdb)
5107 kdb-start.c (Main loop for the standalone kernel debugger)
5109 Configurations that have been declared obsolete in this release have
5110 been commented out. Unless there is activity to revive these
5111 configurations, the next release of GDB will have their sources
5112 permanently REMOVED.
5114 * REMOVED configurations and files
5116 Altos 3068 m68*-altos-*
5117 Convex c1-*-*, c2-*-*
5119 ARM RISCix arm-*-* (as host)
5123 * GDB has been converted to ISO C.
5125 GDB's source code has been converted to ISO C. In particular, the
5126 sources are fully protoized, and rely on standard headers being
5131 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5133 * The MI enabled by default.
5135 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5136 revised and enabled by default. Packages which use GDB as a debugging
5137 engine behind a UI or another front end are encouraged to switch to
5138 using the GDB/MI interface, instead of the old annotations interface
5139 which is now deprecated.
5141 * Support for debugging Pascal programs.
5143 GDB now includes support for debugging Pascal programs. The following
5144 main features are supported:
5146 - Pascal-specific data types such as sets;
5148 - automatic recognition of Pascal sources based on file-name
5151 - Pascal-style display of data types, variables, and functions;
5153 - a Pascal expression parser.
5155 However, some important features are not yet supported.
5157 - Pascal string operations are not supported at all;
5159 - there are some problems with boolean types;
5161 - Pascal type hexadecimal constants are not supported
5162 because they conflict with the internal variables format;
5164 - support for Pascal objects and classes is not full yet;
5166 - unlike Pascal, GDB is case-sensitive for symbol names.
5168 * Changes in completion.
5170 Commands such as `shell', `run' and `set args', which pass arguments
5171 to inferior programs, now complete on file names, similar to what
5172 users expect at the shell prompt.
5174 Commands which accept locations, such as `disassemble', `print',
5175 `breakpoint', `until', etc. now complete on filenames as well as
5176 program symbols. Thus, if you type "break foob TAB", and the source
5177 files linked into the programs include `foobar.c', that file name will
5178 be one of the candidates for completion. However, file names are not
5179 considered for completion after you typed a colon that delimits a file
5180 name from a name of a function in that file, as in "break foo.c:bar".
5182 `set demangle-style' completes on available demangling styles.
5184 * New platform-independent commands:
5186 It is now possible to define a post-hook for a command as well as a
5187 hook that runs before the command. For more details, see the
5188 documentation of `hookpost' in the GDB manual.
5190 * Changes in GNU/Linux native debugging.
5192 Support for debugging multi-threaded programs has been completely
5193 revised for all platforms except m68k and sparc. You can now debug as
5194 many threads as your system allows you to have.
5196 Attach/detach is supported for multi-threaded programs.
5198 Support for SSE registers was added for x86. This doesn't work for
5199 multi-threaded programs though.
5201 * Changes in MIPS configurations.
5203 Multi-arch support is enabled for all MIPS configurations.
5205 GDB can now be built as native debugger on SGI Irix 6.x systems for
5206 debugging n32 executables. (Debugging 64-bit executables is not yet
5209 * Unified support for hardware watchpoints in all x86 configurations.
5211 Most (if not all) native x86 configurations support hardware-assisted
5212 breakpoints and watchpoints in a unified manner. This support
5213 implements debug register sharing between watchpoints, which allows to
5214 put a virtually infinite number of watchpoints on the same address,
5215 and also supports watching regions up to 16 bytes with several debug
5218 The new maintenance command `maintenance show-debug-regs' toggles
5219 debugging print-outs in functions that insert, remove, and test
5220 watchpoints and hardware breakpoints.
5222 * Changes in the DJGPP native configuration.
5224 New command ``info dos sysinfo'' displays assorted information about
5225 the CPU, OS, memory, and DPMI server.
5227 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5228 display information about segment descriptors stored in GDT, LDT, and
5231 New commands ``info dos pde'' and ``info dos pte'' display entries
5232 from Page Directory and Page Tables (for now works with CWSDPMI only).
5233 New command ``info dos address-pte'' displays the Page Table entry for
5234 a given linear address.
5236 GDB can now pass command lines longer than 126 characters to the
5237 program being debugged (requires an update to the libdbg.a library
5238 which is part of the DJGPP development kit).
5240 DWARF2 debug info is now supported.
5242 It is now possible to `step' and `next' through calls to `longjmp'.
5244 * Changes in documentation.
5246 All GDB documentation was converted to GFDL, the GNU Free
5247 Documentation License.
5249 Tracepoints-related commands are now fully documented in the GDB
5252 TUI, the Text-mode User Interface, is now documented in the manual.
5254 Tracepoints-related commands are now fully documented in the GDB
5257 The "GDB Internals" manual now has an index. It also includes
5258 documentation of `ui_out' functions, GDB coding standards, x86
5259 hardware watchpoints, and memory region attributes.
5261 * GDB's version number moved to ``version.in''
5263 The Makefile variable VERSION has been replaced by the file
5264 ``version.in''. People creating GDB distributions should update the
5265 contents of this file.
5269 GUD support is now a standard part of the EMACS distribution.
5271 *** Changes in GDB 5.0:
5273 * Improved support for debugging FP programs on x86 targets
5275 Unified and much-improved support for debugging floating-point
5276 programs on all x86 targets. In particular, ``info float'' now
5277 displays the FP registers in the same format on all x86 targets, with
5278 greater level of detail.
5280 * Improvements and bugfixes in hardware-assisted watchpoints
5282 It is now possible to watch array elements, struct members, and
5283 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5284 on x86 targets no longer erroneously trigger when the address is
5287 * Improvements in the native DJGPP version of GDB
5289 The distribution now includes all the scripts and auxiliary files
5290 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5291 machines ``out of the box''.
5293 The DJGPP version can now debug programs that use signals. It is
5294 possible to catch signals that happened in the debuggee, deliver
5295 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5296 would kill the program being debugged.) Programs that hook hardware
5297 interrupts (keyboard, timer, etc.) can also be debugged.
5299 It is now possible to debug DJGPP programs that redirect their
5300 standard handles or switch them to raw (as opposed to cooked) mode, or
5301 even close them. The command ``run < foo > bar'' works as expected,
5302 and ``info terminal'' reports useful information about the debuggee's
5303 terminal, including raw/cooked mode, redirection, etc.
5305 The DJGPP version now uses termios functions for console I/O, which
5306 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5309 DOS-style file names with drive letters are now fully supported by
5312 It is now possible to debug DJGPP programs that switch their working
5313 directory. It is also possible to rerun the debuggee any number of
5314 times without restarting GDB; thus, you can use the same setup,
5315 breakpoints, etc. for many debugging sessions.
5317 * New native configurations
5319 ARM GNU/Linux arm*-*-linux*
5320 PowerPC GNU/Linux powerpc-*-linux*
5324 Motorola MCore mcore-*-*
5325 x86 VxWorks i[3456]86-*-vxworks*
5326 PowerPC VxWorks powerpc-*-vxworks*
5327 TI TMS320C80 tic80-*-*
5329 * OBSOLETE configurations
5331 Altos 3068 m68*-altos-*
5332 Convex c1-*-*, c2-*-*
5334 ARM RISCix arm-*-* (as host)
5337 Configurations that have been declared obsolete will be commented out,
5338 but the code will be left in place. If there is no activity to revive
5339 these configurations before the next release of GDB, the sources will
5340 be permanently REMOVED.
5342 * Gould support removed
5344 Support for the Gould PowerNode and NP1 has been removed.
5346 * New features for SVR4
5348 On SVR4 native platforms (such as Solaris), if you attach to a process
5349 without first loading a symbol file, GDB will now attempt to locate and
5350 load symbols from the running process's executable file.
5352 * Many C++ enhancements
5354 C++ support has been greatly improved. Overload resolution now works properly
5355 in almost all cases. RTTI support is on the way.
5357 * Remote targets can connect to a sub-program
5359 A popen(3) style serial-device has been added. This device starts a
5360 sub-process (such as a stand-alone simulator) and then communicates
5361 with that. The sub-program to run is specified using the syntax
5362 ``|<program> <args>'' vis:
5364 (gdb) set remotedebug 1
5365 (gdb) target extended-remote |mn10300-elf-sim program-args
5367 * MIPS 64 remote protocol
5369 A long standing bug in the mips64 remote protocol where by GDB
5370 expected certain 32 bit registers (ex SR) to be transfered as 32
5371 instead of 64 bits has been fixed.
5373 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5374 added to provide backward compatibility with older versions of GDB.
5376 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5378 The command ``set remotebinarydownload'' command has been replaced by
5379 ``set remote X-packet''. Other commands in ``set remote'' family
5380 include ``set remote P-packet''.
5382 * Breakpoint commands accept ranges.
5384 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5385 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5386 ``tracepoint passcount'' also accepts a range of tracepoints.
5388 * ``apropos'' command added.
5390 The ``apropos'' command searches through command names and
5391 documentation strings, printing out matches, making it much easier to
5392 try to find a command that does what you are looking for.
5396 A new machine oriented interface (MI) has been added to GDB. This
5397 interface is designed for debug environments running GDB as a separate
5398 process. This is part of the long term libGDB project. See the
5399 "GDB/MI" chapter of the GDB manual for further information. It can be
5400 enabled by configuring with:
5402 .../configure --enable-gdbmi
5404 *** Changes in GDB-4.18:
5406 * New native configurations
5408 HP-UX 10.20 hppa*-*-hpux10.20
5409 HP-UX 11.x hppa*-*-hpux11.0*
5410 M68K GNU/Linux m68*-*-linux*
5414 Fujitsu FR30 fr30-*-elf*
5415 Intel StrongARM strongarm-*-*
5416 Mitsubishi D30V d30v-*-*
5418 * OBSOLETE configurations
5420 Gould PowerNode, NP1 np1-*-*, pn-*-*
5422 Configurations that have been declared obsolete will be commented out,
5423 but the code will be left in place. If there is no activity to revive
5424 these configurations before the next release of GDB, the sources will
5425 be permanently REMOVED.
5429 As a compatibility experiment, GDB's source files buildsym.h and
5430 buildsym.c have been converted to pure standard C, no longer
5431 containing any K&R compatibility code. We believe that all systems in
5432 use today either come with a standard C compiler, or have a GCC port
5433 available. If this is not true, please report the affected
5434 configuration to bug-gdb@gnu.org immediately. See the README file for
5435 information about getting a standard C compiler if you don't have one
5440 GDB now uses readline 2.2.
5442 * set extension-language
5444 You can now control the mapping between filename extensions and source
5445 languages by using the `set extension-language' command. For instance,
5446 you can ask GDB to treat .c files as C++ by saying
5447 set extension-language .c c++
5448 The command `info extensions' lists all of the recognized extensions
5449 and their associated languages.
5451 * Setting processor type for PowerPC and RS/6000
5453 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5454 you can use the `set processor' command to specify what variant of the
5455 PowerPC family you are debugging. The command
5459 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5460 following PowerPC and RS6000 variants:
5462 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5463 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5465 403GC IBM PowerPC 403GC
5466 505 Motorola PowerPC 505
5467 860 Motorola PowerPC 860 or 850
5468 601 Motorola PowerPC 601
5469 602 Motorola PowerPC 602
5470 603 Motorola/IBM PowerPC 603 or 603e
5471 604 Motorola PowerPC 604 or 604e
5472 750 Motorola/IBM PowerPC 750 or 750
5474 At the moment, this command just tells GDB what to name the
5475 special-purpose processor registers. Since almost all the affected
5476 registers are inaccessible to user-level programs, this command is
5477 only useful for remote debugging in its present form.
5481 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5482 more extensive support for HP-UX. Added features include shared
5483 library support, kernel threads and hardware watchpoints for 11.00,
5484 support for HP's ANSI C and C++ compilers, and a compatibility mode
5485 for xdb and dbx commands.
5489 HP's donation includes the new concept of catchpoints, which is a
5490 generalization of the old catch command. On HP-UX, it is now possible
5491 to catch exec, fork, and vfork, as well as library loading.
5493 This means that the existing catch command has changed; its first
5494 argument now specifies the type of catch to be set up. See the
5495 output of "help catch" for a list of catchpoint types.
5497 * Debugging across forks
5499 On HP-UX, you can choose which process to debug when a fork() happens
5504 HP has donated a curses-based terminal user interface (TUI). To get
5505 it, build with --enable-tui. Although this can be enabled for any
5506 configuration, at present it only works for native HP debugging.
5508 * GDB remote protocol additions
5510 A new protocol packet 'X' that writes binary data is now available.
5511 Default behavior is to try 'X', then drop back to 'M' if the stub
5512 fails to respond. The settable variable `remotebinarydownload'
5513 allows explicit control over the use of 'X'.
5515 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5516 full 64-bit address. The command
5518 set remoteaddresssize 32
5520 can be used to revert to the old behaviour. For existing remote stubs
5521 the change should not be noticed, as the additional address information
5524 In order to assist in debugging stubs, you may use the maintenance
5525 command `packet' to send any text string to the stub. For instance,
5527 maint packet heythere
5529 sends the packet "$heythere#<checksum>". Note that it is very easy to
5530 disrupt a debugging session by sending the wrong packet at the wrong
5533 The compare-sections command allows you to compare section data on the
5534 target to what is in the executable file without uploading or
5535 downloading, by comparing CRC checksums.
5537 * Tracing can collect general expressions
5539 You may now collect general expressions at tracepoints. This requires
5540 further additions to the target-side stub; see tracepoint.c and
5541 doc/agentexpr.texi for further details.
5543 * mask-address variable for Mips
5545 For Mips targets, you may control the zeroing of the upper 32 bits of
5546 a 64-bit address by entering `set mask-address on'. This is mainly
5547 of interest to users of embedded R4xxx and R5xxx processors.
5549 * Higher serial baud rates
5551 GDB's serial code now allows you to specify baud rates 57600, 115200,
5552 230400, and 460800 baud. (Note that your host system may not be able
5553 to achieve all of these rates.)
5557 The i960 configuration now includes an initial implementation of a
5558 builtin simulator, contributed by Jim Wilson.
5561 *** Changes in GDB-4.17:
5563 * New native configurations
5565 Alpha GNU/Linux alpha*-*-linux*
5566 Unixware 2.x i[3456]86-unixware2*
5567 Irix 6.x mips*-sgi-irix6*
5568 PowerPC GNU/Linux powerpc-*-linux*
5569 PowerPC Solaris powerpcle-*-solaris*
5570 Sparc GNU/Linux sparc-*-linux*
5571 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5575 Argonaut Risc Chip (ARC) arc-*-*
5576 Hitachi H8/300S h8300*-*-*
5577 Matsushita MN10200 w/simulator mn10200-*-*
5578 Matsushita MN10300 w/simulator mn10300-*-*
5579 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5580 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5581 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5582 Mitsubishi D10V w/simulator d10v-*-*
5583 Mitsubishi M32R/D w/simulator m32r-*-elf*
5584 Tsqware Sparclet sparclet-*-*
5585 NEC V850 w/simulator v850-*-*
5587 * New debugging protocols
5589 ARM with RDI protocol arm*-*-*
5590 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5591 DDB and LSI variants of PMON protocol mips*-*-*
5592 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5593 PowerPC with SDS protocol powerpc{,le}-*-eabi
5594 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5598 All configurations can now understand and use the DWARF 2 debugging
5599 format. The choice is automatic, if the symbol file contains DWARF 2
5604 GDB now includes basic Java language support. This support is
5605 only useful with Java compilers that produce native machine code.
5607 * solib-absolute-prefix and solib-search-path
5609 For SunOS and SVR4 shared libraries, you may now set the prefix for
5610 loading absolute shared library symbol files, and the search path for
5611 locating non-absolute shared library symbol files.
5613 * Live range splitting
5615 GDB can now effectively debug code for which GCC has performed live
5616 range splitting as part of its optimization. See gdb/doc/LRS for
5617 more details on the expected format of the stabs information.
5621 GDB's support for the GNU Hurd, including thread debugging, has been
5622 updated to work with current versions of the Hurd.
5626 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5627 instruction set. ARM GDB automatically detects when Thumb
5628 instructions are in use, and adjusts disassembly and backtracing
5633 GDB's MIPS target configurations now handle the MIP16 16-bit
5638 GDB now includes support for overlays; if an executable has been
5639 linked such that multiple sections are based at the same address, GDB
5640 will decide which section to use for symbolic info. You can choose to
5641 control the decision manually, using overlay commands, or implement
5642 additional target-side support and use "overlay load-target" to bring
5643 in the overlay mapping. Do "help overlay" for more detail.
5647 The command "info symbol <address>" displays information about
5648 the symbol at the specified address.
5652 The standard remote protocol now includes an extension that allows
5653 asynchronous collection and display of trace data. This requires
5654 extensive support in the target-side debugging stub. Tracing mode
5655 includes a new interaction mode in GDB and new commands: see the
5656 file tracepoint.c for more details.
5660 Configurations for embedded MIPS now include a simulator contributed
5661 by Cygnus Solutions. The simulator supports the instruction sets
5662 of most MIPS variants.
5666 Sparc configurations may now include the ERC32 simulator contributed
5667 by the European Space Agency. The simulator is not built into
5668 Sparc targets by default; configure with --enable-sim to include it.
5672 For target configurations that may include multiple variants of a
5673 basic architecture (such as MIPS and SH), you may now set the
5674 architecture explicitly. "set arch" sets, "info arch" lists
5675 the possible architectures.
5677 *** Changes in GDB-4.16:
5679 * New native configurations
5681 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5682 M68K NetBSD m68k-*-netbsd*
5683 PowerPC AIX 4.x powerpc-*-aix*
5684 PowerPC MacOS powerpc-*-macos*
5685 PowerPC Windows NT powerpcle-*-cygwin32
5686 RS/6000 AIX 4.x rs6000-*-aix4*
5690 ARM with RDP protocol arm-*-*
5691 I960 with MON960 i960-*-coff
5692 MIPS VxWorks mips*-*-vxworks*
5693 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5694 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5696 Matra Sparclet sparclet-*-*
5700 The powerpc-eabi configuration now includes the PSIM simulator,
5701 contributed by Andrew Cagney, with assistance from Mike Meissner.
5702 PSIM is a very elaborate model of the PowerPC, including not only
5703 basic instruction set execution, but also details of execution unit
5704 performance and I/O hardware. See sim/ppc/README for more details.
5708 GDB now works with Solaris 2.5.
5710 * Windows 95/NT native
5712 GDB will now work as a native debugger on Windows 95 and Windows NT.
5713 To build it from source, you must use the "gnu-win32" environment,
5714 which uses a DLL to emulate enough of Unix to run the GNU tools.
5715 Further information, binaries, and sources are available at
5716 ftp.cygnus.com, under pub/gnu-win32.
5718 * dont-repeat command
5720 If a user-defined command includes the command `dont-repeat', then the
5721 command will not be repeated if the user just types return. This is
5722 useful if the command is time-consuming to run, so that accidental
5723 extra keystrokes don't run the same command many times.
5725 * Send break instead of ^C
5727 The standard remote protocol now includes an option to send a break
5728 rather than a ^C to the target in order to interrupt it. By default,
5729 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5731 * Remote protocol timeout
5733 The standard remote protocol includes a new variable `remotetimeout'
5734 that allows you to set the number of seconds before GDB gives up trying
5735 to read from the target. The default value is 2.
5737 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5739 By default GDB will automatically keep track of objects as they are
5740 loaded and unloaded by the dynamic linker. By using the command `set
5741 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5742 when shared library events occur, thus allowing you to set breakpoints
5743 in shared libraries which are explicitly loaded by the inferior.
5745 Note this feature does not work on hpux8. On hpux9 you must link
5746 /usr/lib/end.o into your program. This feature should work
5747 automatically on hpux10.
5749 * Irix 5.x hardware watchpoint support
5751 Irix 5 configurations now support the use of hardware watchpoints.
5753 * Mips protocol "SYN garbage limit"
5755 When debugging a Mips target using the `target mips' protocol, you
5756 may set the number of characters that GDB will ignore by setting
5757 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5758 every character. The default value is 1050.
5760 * Recording and replaying remote debug sessions
5762 If you set `remotelogfile' to the name of a file, gdb will write to it
5763 a recording of a remote debug session. This recording may then be
5764 replayed back to gdb using "gdbreplay". See gdbserver/README for
5765 details. This is useful when you have a problem with GDB while doing
5766 remote debugging; you can make a recording of the session and send it
5767 to someone else, who can then recreate the problem.
5769 * Speedups for remote debugging
5771 GDB includes speedups for downloading and stepping MIPS systems using
5772 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5773 and more efficient S-record downloading.
5775 * Memory use reductions and statistics collection
5777 GDB now uses less memory and reports statistics about memory usage.
5778 Try the `maint print statistics' command, for example.
5780 *** Changes in GDB-4.15:
5782 * Psymtabs for XCOFF
5784 The symbol reader for AIX GDB now uses partial symbol tables. This
5785 can greatly improve startup time, especially for large executables.
5787 * Remote targets use caching
5789 Remote targets now use a data cache to speed up communication with the
5790 remote side. The data cache could lead to incorrect results because
5791 it doesn't know about volatile variables, thus making it impossible to
5792 debug targets which use memory mapped I/O devices. `set remotecache
5793 off' turns the the data cache off.
5795 * Remote targets may have threads
5797 The standard remote protocol now includes support for multiple threads
5798 in the target system, using new protocol commands 'H' and 'T'. See
5799 gdb/remote.c for details.
5803 If GDB is configured with `--enable-netrom', then it will include
5804 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5805 acts as though it is a bank of ROM on the target board, but you can
5806 write into it over the network. GDB's support consists only of
5807 support for fast loading into the emulated ROM; to debug, you must use
5808 another protocol, such as standard remote protocol. The usual
5809 sequence is something like
5811 target nrom <netrom-hostname>
5813 target remote <netrom-hostname>:1235
5817 GDB now includes support for the Apple Macintosh, as a host only. It
5818 may be run as either an MPW tool or as a standalone application, and
5819 it can debug through the serial port. All the usual GDB commands are
5820 available, but to the target command, you must supply "serial" as the
5821 device type instead of "/dev/ttyXX". See mpw-README in the main
5822 directory for more information on how to build. The MPW configuration
5823 scripts */mpw-config.in support only a few targets, and only the
5824 mips-idt-ecoff target has been tested.
5828 GDB configuration now uses autoconf. This is not user-visible,
5829 but does simplify configuration and building.
5833 GDB now supports hpux10.
5835 *** Changes in GDB-4.14:
5837 * New native configurations
5839 x86 FreeBSD i[345]86-*-freebsd
5840 x86 NetBSD i[345]86-*-netbsd
5841 NS32k NetBSD ns32k-*-netbsd
5842 Sparc NetBSD sparc-*-netbsd
5846 A29K VxWorks a29k-*-vxworks
5847 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5848 CPU32 EST-300 emulator m68*-*-est*
5849 PowerPC ELF powerpc-*-elf
5852 * Alpha OSF/1 support for procfs
5854 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5855 possible to attach to running processes. As the mounting of the /proc
5856 filesystem is optional on the Alpha, GDB automatically determines
5857 the availability of /proc during startup. This can lead to problems
5858 if /proc is unmounted after GDB has been started.
5860 * Arguments to user-defined commands
5862 User commands may accept up to 10 arguments separated by whitespace.
5863 Arguments are accessed within the user command via $arg0..$arg9. A
5866 print $arg0 + $arg1 + $arg2
5868 To execute the command use:
5871 Defines the command "adder" which prints the sum of its three arguments.
5872 Note the arguments are text substitutions, so they may reference variables,
5873 use complex expressions, or even perform inferior function calls.
5875 * New `if' and `while' commands
5877 This makes it possible to write more sophisticated user-defined
5878 commands. Both commands take a single argument, which is the
5879 expression to evaluate, and must be followed by the commands to
5880 execute, one per line, if the expression is nonzero, the list being
5881 terminated by the word `end'. The `if' command list may include an
5882 `else' word, which causes the following commands to be executed only
5883 if the expression is zero.
5885 * Fortran source language mode
5887 GDB now includes partial support for Fortran 77. It will recognize
5888 Fortran programs and can evaluate a subset of Fortran expressions, but
5889 variables and functions may not be handled correctly. GDB will work
5890 with G77, but does not yet know much about symbols emitted by other
5893 * Better HPUX support
5895 Most debugging facilities now work on dynamic executables for HPPAs
5896 running hpux9 or later. You can attach to running dynamically linked
5897 processes, but by default the dynamic libraries will be read-only, so
5898 for instance you won't be able to put breakpoints in them. To change
5899 that behavior do the following before running the program:
5905 This will cause the libraries to be mapped private and read-write.
5906 To revert to the normal behavior, do this:
5912 You cannot set breakpoints or examine data in the library until after
5913 the library is loaded if the function/data symbols do not have
5916 GDB can now also read debug symbols produced by the HP C compiler on
5917 HPPAs (sorry, no C++, Fortran or 68k support).
5919 * Target byte order now dynamically selectable
5921 You can choose which byte order to use with a target system, via the
5922 commands "set endian big" and "set endian little", and you can see the
5923 current setting by using "show endian". You can also give the command
5924 "set endian auto", in which case GDB will use the byte order
5925 associated with the executable. Currently, only embedded MIPS
5926 configurations support dynamic selection of target byte order.
5928 * New DOS host serial code
5930 This version uses DPMI interrupts to handle buffered I/O, so you
5931 no longer need to run asynctsr when debugging boards connected to
5934 *** Changes in GDB-4.13:
5936 * New "complete" command
5938 This lists all the possible completions for the rest of the line, if it
5939 were to be given as a command itself. This is intended for use by emacs.
5941 * Trailing space optional in prompt
5943 "set prompt" no longer adds a space for you after the prompt you set. This
5944 allows you to set a prompt which ends in a space or one that does not.
5946 * Breakpoint hit counts
5948 "info break" now displays a count of the number of times the breakpoint
5949 has been hit. This is especially useful in conjunction with "ignore"; you
5950 can ignore a large number of breakpoint hits, look at the breakpoint info
5951 to see how many times the breakpoint was hit, then run again, ignoring one
5952 less than that number, and this will get you quickly to the last hit of
5955 * Ability to stop printing at NULL character
5957 "set print null-stop" will cause GDB to stop printing the characters of
5958 an array when the first NULL is encountered. This is useful when large
5959 arrays actually contain only short strings.
5961 * Shared library breakpoints
5963 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5964 breakpoints in shared libraries before the executable is run.
5966 * Hardware watchpoints
5968 There is a new hardware breakpoint for the watch command for sparclite
5969 targets. See gdb/sparclite/hw_breakpoint.note.
5971 Hardware watchpoints are also now supported under GNU/Linux.
5975 Annotations have been added. These are for use with graphical interfaces,
5976 and are still experimental. Currently only gdba.el uses these.
5978 * Improved Irix 5 support
5980 GDB now works properly with Irix 5.2.
5982 * Improved HPPA support
5984 GDB now works properly with the latest GCC and GAS.
5986 * New native configurations
5988 Sequent PTX4 i[34]86-sequent-ptx4
5989 HPPA running OSF/1 hppa*-*-osf*
5990 Atari TT running SVR4 m68*-*-sysv4*
5991 RS/6000 LynxOS rs6000-*-lynxos*
5995 OS/9000 i[34]86-*-os9k
5996 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5999 * Hitachi SH7000 and E7000-PC ICE support
6001 There is now support for communicating with the Hitachi E7000-PC ICE.
6002 This is available automatically when GDB is configured for the SH.
6006 As usual, a variety of small fixes and improvements, both generic
6007 and configuration-specific. See the ChangeLog for more detail.
6009 *** Changes in GDB-4.12:
6011 * Irix 5 is now supported
6015 GDB-4.12 on the HPPA has a number of changes which make it unable
6016 to debug the output from the currently released versions of GCC and
6017 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6018 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6019 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6022 *** Changes in GDB-4.11:
6024 * User visible changes:
6028 The "set remotedebug" option is now consistent between the mips remote
6029 target, remote targets using the gdb-specific protocol, UDI (AMD's
6030 debug protocol for the 29k) and the 88k bug monitor. It is now an
6031 integer specifying a debug level (normally 0 or 1, but 2 means more
6032 debugging info for the mips target).
6034 * DEC Alpha native support
6036 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6037 debug info, but GDB works fairly well with the DEC compiler and should
6038 work with a future GCC release. See the README file for a few
6039 Alpha-specific notes.
6041 * Preliminary thread implementation
6043 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6045 * LynxOS native and target support for 386
6047 This release has been hosted on LynxOS 2.2, and also can be configured
6048 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6051 * Improvements in C++ mangling/demangling.
6053 This release has much better g++ debugging, specifically in name
6054 mangling/demangling, virtual function calls, print virtual table,
6055 call methods, ...etc.
6057 *** Changes in GDB-4.10:
6059 * User visible changes:
6061 Remote debugging using the GDB-specific (`target remote') protocol now
6062 supports the `load' command. This is only useful if you have some
6063 other way of getting the stub to the target system, and you can put it
6064 somewhere in memory where it won't get clobbered by the download.
6066 Filename completion now works.
6068 When run under emacs mode, the "info line" command now causes the
6069 arrow to point to the line specified. Also, "info line" prints
6070 addresses in symbolic form (as well as hex).
6072 All vxworks based targets now support a user settable option, called
6073 vxworks-timeout. This option represents the number of seconds gdb
6074 should wait for responses to rpc's. You might want to use this if
6075 your vxworks target is, perhaps, a slow software simulator or happens
6076 to be on the far side of a thin network line.
6080 This release contains support for using a DEC alpha as a GDB host for
6081 cross debugging. Native alpha debugging is not supported yet.
6084 *** Changes in GDB-4.9:
6088 This is the first GDB release which is accompanied by a matching testsuite.
6089 The testsuite requires installation of dejagnu, which should be available
6090 via ftp from most sites that carry GNU software.
6094 'Cfront' style demangling has had its name changed to 'ARM' style, to
6095 emphasize that it was written from the specifications in the C++ Annotated
6096 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6097 disclaimers, it still generated too much confusion with users attempting to
6098 use gdb with AT&T cfront.
6102 GDB now uses a standard remote interface to a simulator library.
6103 So far, the library contains simulators for the Zilog Z8001/2, the
6104 Hitachi H8/300, H8/500 and Super-H.
6106 * New targets supported
6108 H8/300 simulator h8300-hitachi-hms or h8300hms
6109 H8/500 simulator h8500-hitachi-hms or h8500hms
6110 SH simulator sh-hitachi-hms or sh
6111 Z8000 simulator z8k-zilog-none or z8ksim
6112 IDT MIPS board over serial line mips-idt-ecoff
6114 Cross-debugging to GO32 targets is supported. It requires a custom
6115 version of the i386-stub.c module which is integrated with the
6116 GO32 memory extender.
6118 * New remote protocols
6120 MIPS remote debugging protocol.
6122 * New source languages supported
6124 This version includes preliminary support for Chill, a Pascal like language
6125 used by telecommunications companies. Chill support is also being integrated
6126 into the GNU compiler, but we don't know when it will be publically available.
6129 *** Changes in GDB-4.8:
6131 * HP Precision Architecture supported
6133 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6134 version of this support was available as a set of patches from the
6135 University of Utah. GDB does not support debugging of programs
6136 compiled with the HP compiler, because HP will not document their file
6137 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6138 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6140 Many problems in the preliminary version have been fixed.
6142 * Faster and better demangling
6144 We have improved template demangling and fixed numerous bugs in the GNU style
6145 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6146 character types (wchar_t) are now supported. Demangling of each symbol is now
6147 only done once, and is cached when the symbol table for a file is read in.
6148 This results in a small increase in memory usage for C programs, a moderate
6149 increase in memory usage for C++ programs, and a fantastic speedup in
6152 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6153 from the specifications in the Annotated Reference Manual, which AT&T's
6154 compiler does not actually implement.
6156 * G++ multiple inheritance compiler problem
6158 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6159 inheritance lattices was reworked to properly discover ambiguities. We
6160 recently found an example which causes this new algorithm to fail in a
6161 very subtle way, producing bad debug information for those classes.
6162 The file 'gcc.patch' (in this directory) can be applied to gcc to
6163 circumvent the problem. A future GCC release will contain a complete
6166 The previous G++ debug info problem (mentioned below for the gdb-4.7
6167 release) is fixed in gcc version 2.3.2.
6169 * Improved configure script
6171 The `configure' script will now attempt to guess your system type if
6172 you don't supply a host system type. The old scheme of supplying a
6173 host system triplet is preferable over using this. All the magic is
6174 done in the new `config.guess' script. Examine it for details.
6176 We have also brought our configure script much more in line with the FSF's
6177 version. It now supports the --with-xxx options. In particular,
6178 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6179 The resulting GDB will not be able to read arbitrary object file formats --
6180 only the format ``expected'' to be used on the configured target system.
6181 We hope to make this the default in a future release.
6183 * Documentation improvements
6185 There's new internal documentation on how to modify GDB, and how to
6186 produce clean changes to the code. We implore people to read it
6187 before submitting changes.
6189 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6190 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6191 `info' files are also provided. To build `info' files from scratch,
6192 you will need the latest `makeinfo' release, which will be available in
6193 a future texinfo-X.Y release.
6195 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6196 We're not sure exactly which versions have this problem, but it has
6197 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6198 or better. If that isn't possible, there is a patch in
6199 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6200 around this problem.
6204 GDB now supports array constants that can be used in expressions typed in by
6205 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6206 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6209 The new directory `gdb/sparclite' contains a program that demonstrates
6210 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6212 * New native hosts supported
6214 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6215 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6217 * New targets supported
6219 AMD 29k family via UDI a29k-amd-udi or udi29k
6221 * New file formats supported
6223 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6224 HPUX core files, and SCO 3.2v2 core files.
6228 Attaching to processes now works again; thanks for the many bug reports.
6230 We have also stomped on a bunch of core dumps caused by
6231 printf_filtered("%s") problems.
6233 We eliminated a copyright problem on the rpc and ptrace header files
6234 for VxWorks, which was discovered at the last minute during the 4.7
6235 release. You should now be able to build a VxWorks GDB.
6237 You can now interrupt gdb while an attached process is running. This
6238 will cause the attached process to stop, and give control back to GDB.
6240 We fixed problems caused by using too many file descriptors
6241 for reading symbols from object files and libraries. This was
6242 especially a problem for programs that used many (~100) shared
6245 The `step' command now only enters a subroutine if there is line number
6246 information for the subroutine. Otherwise it acts like the `next'
6247 command. Previously, `step' would enter subroutines if there was
6248 any debugging information about the routine. This avoids problems
6249 when using `cc -g1' on MIPS machines.
6251 * Internal improvements
6253 GDB's internal interfaces have been improved to make it easier to support
6254 debugging of multiple languages in the future.
6256 GDB now uses a common structure for symbol information internally.
6257 Minimal symbols (derived from linkage symbols in object files), partial
6258 symbols (from a quick scan of debug information), and full symbols
6259 contain a common subset of information, making it easier to write
6260 shared code that handles any of them.
6262 * New command line options
6264 We now accept --silent as an alias for --quiet.
6268 The memory-mapped-malloc library is now licensed under the GNU Library
6269 General Public License.
6271 *** Changes in GDB-4.7:
6273 * Host/native/target split
6275 GDB has had some major internal surgery to untangle the support for
6276 hosts and remote targets. Now, when you configure GDB for a remote
6277 target, it will no longer load in all of the support for debugging
6278 local programs on the host. When fully completed and tested, this will
6279 ensure that arbitrary host/target combinations are possible.
6281 The primary conceptual shift is to separate the non-portable code in
6282 GDB into three categories. Host specific code is required any time GDB
6283 is compiled on that host, regardless of the target. Target specific
6284 code relates to the peculiarities of the target, but can be compiled on
6285 any host. Native specific code is everything else: it can only be
6286 built when the host and target are the same system. Child process
6287 handling and core file support are two common `native' examples.
6289 GDB's use of /proc for controlling Unix child processes is now cleaner.
6290 It has been split out into a single module under the `target_ops' vector,
6291 plus two native-dependent functions for each system that uses /proc.
6293 * New hosts supported
6295 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6296 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6297 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6299 * New targets supported
6301 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6302 68030 and CPU32 m68030-*-*, m68332-*-*
6304 * New native hosts supported
6306 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6307 (386bsd is not well tested yet)
6308 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6310 * New file formats supported
6312 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6313 supports reading of `a.out.adobe' object files, which are an a.out
6314 format extended with minimal information about multiple sections.
6318 `show copying' is the same as the old `info copying'.
6319 `show warranty' is the same as `info warrantee'.
6320 These were renamed for consistency. The old commands continue to work.
6322 `info handle' is a new alias for `info signals'.
6324 You can now define pre-command hooks, which attach arbitrary command
6325 scripts to any command. The commands in the hook will be executed
6326 prior to the user's command. You can also create a hook which will be
6327 executed whenever the program stops. See gdb.texinfo.
6331 We now deal with Cfront style name mangling, and can even extract type
6332 info from mangled symbols. GDB can automatically figure out which
6333 symbol mangling style your C++ compiler uses.
6335 Calling of methods and virtual functions has been improved as well.
6339 The crash that occured when debugging Sun Ansi-C compiled binaries is
6340 fixed. This was due to mishandling of the extra N_SO stabs output
6343 We also finally got Ultrix 4.2 running in house, and fixed core file
6344 support, with help from a dozen people on the net.
6346 John M. Farrell discovered that the reason that single-stepping was so
6347 slow on all of the Mips based platforms (primarily SGI and DEC) was
6348 that we were trying to demangle and lookup a symbol used for internal
6349 purposes on every instruction that was being stepped through. Changing
6350 the name of that symbol so that it couldn't be mistaken for a C++
6351 mangled symbol sped things up a great deal.
6353 Rich Pixley sped up symbol lookups in general by getting much smarter
6354 about when C++ symbol mangling is necessary. This should make symbol
6355 completion (TAB on the command line) much faster. It's not as fast as
6356 we'd like, but it's significantly faster than gdb-4.6.
6360 A new user controllable variable 'call_scratch_address' can
6361 specify the location of a scratch area to be used when GDB
6362 calls a function in the target. This is necessary because the
6363 usual method of putting the scratch area on the stack does not work
6364 in systems that have separate instruction and data spaces.
6366 We integrated changes to support the 29k UDI (Universal Debugger
6367 Interface), but discovered at the last minute that we didn't have all
6368 of the appropriate copyright paperwork. We are working with AMD to
6369 resolve this, and hope to have it available soon.
6373 We have sped up the remote serial line protocol, especially for targets
6374 with lots of registers. It now supports a new `expedited status' ('T')
6375 message which can be used in place of the existing 'S' status message.
6376 This allows the remote stub to send only the registers that GDB
6377 needs to make a quick decision about single-stepping or conditional
6378 breakpoints, eliminating the need to fetch the entire register set for
6379 each instruction being stepped through.
6381 The GDB remote serial protocol now implements a write-through cache for
6382 registers, only re-reading the registers if the target has run.
6384 There is also a new remote serial stub for SPARC processors. You can
6385 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6386 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6387 processor with a serial port.
6391 Configure.in files have become much easier to read and modify. A new
6392 `table driven' format makes it more obvious what configurations are
6393 supported, and what files each one uses.
6397 There is a new opcodes library which will eventually contain all of the
6398 disassembly routines and opcode tables. At present, it only contains
6399 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6400 disassembler (binutils/objdump) to share these routines.
6402 The libiberty library is now copylefted under the GNU Library General
6403 Public License. This allows more liberal use, and was done so libg++
6404 can use it. This makes no difference to GDB, since the Library License
6405 grants all the rights from the General Public License.
6409 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6410 reference to the stabs symbol info used by the debugger. It is (as far
6411 as we know) the only published document on this fascinating topic. We
6412 encourage you to read it, compare it to the stabs information on your
6413 system, and send improvements on the document in general (to
6414 bug-gdb@prep.ai.mit.edu).
6416 And, of course, many bugs have been fixed.
6419 *** Changes in GDB-4.6:
6421 * Better support for C++ function names
6423 GDB now accepts as input the "demangled form" of C++ overloaded function
6424 names and member function names, and can do command completion on such names
6425 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6426 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6427 Make use of command completion, it is your friend.
6429 GDB also now accepts a variety of C++ mangled symbol formats. They are
6430 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6431 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6432 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6433 for the list of formats.
6435 * G++ symbol mangling problem
6437 Recent versions of gcc have a bug in how they emit debugging information for
6438 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6439 directory) can be applied to gcc to fix the problem. Alternatively, if you
6440 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6441 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6442 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6445 * New 'maintenance' command
6447 All of the commands related to hacking GDB internals have been moved out of
6448 the main command set, and now live behind the 'maintenance' command. This
6449 can also be abbreviated as 'mt'. The following changes were made:
6451 dump-me -> maintenance dump-me
6452 info all-breakpoints -> maintenance info breakpoints
6453 printmsyms -> maintenance print msyms
6454 printobjfiles -> maintenance print objfiles
6455 printpsyms -> maintenance print psymbols
6456 printsyms -> maintenance print symbols
6458 The following commands are new:
6460 maintenance demangle Call internal GDB demangler routine to
6461 demangle a C++ link name and prints the result.
6462 maintenance print type Print a type chain for a given symbol
6464 * Change to .gdbinit file processing
6466 We now read the $HOME/.gdbinit file before processing the argv arguments
6467 (e.g. reading symbol files or core files). This allows global parameters to
6468 be set, which will apply during the symbol reading. The ./.gdbinit is still
6469 read after argv processing.
6471 * New hosts supported
6473 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6475 GNU/Linux support i386-unknown-linux or linux
6477 We are also including code to support the HP/PA running BSD and HPUX. This
6478 is almost guaranteed not to work, as we didn't have time to test or build it
6479 for this release. We are including it so that the more adventurous (or
6480 masochistic) of you can play with it. We also had major problems with the
6481 fact that the compiler that we got from HP doesn't support the -g option.
6484 * New targets supported
6486 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6488 * More smarts about finding #include files
6490 GDB now remembers the compilation directory for all include files, and for
6491 all files from which C is generated (like yacc and lex sources). This
6492 greatly improves GDB's ability to find yacc/lex sources, and include files,
6493 especially if you are debugging your program from a directory different from
6494 the one that contains your sources.
6496 We also fixed a bug which caused difficulty with listing and setting
6497 breakpoints in include files which contain C code. (In the past, you had to
6498 try twice in order to list an include file that you hadn't looked at before.)
6500 * Interesting infernals change
6502 GDB now deals with arbitrary numbers of sections, where the symbols for each
6503 section must be relocated relative to that section's landing place in the
6504 target's address space. This work was needed to support ELF with embedded
6505 stabs used by Solaris-2.0.
6507 * Bug fixes (of course!)
6509 There have been loads of fixes for the following things:
6510 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6511 i960, stabs, DOS(GO32), procfs, etc...
6513 See the ChangeLog for details.
6515 *** Changes in GDB-4.5:
6517 * New machines supported (host and target)
6519 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6521 SGI Irix-4.x mips-sgi-irix4 or iris4
6523 * New malloc package
6525 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6526 Mmalloc is capable of handling mutiple heaps of memory. It is also
6527 capable of saving a heap to a file, and then mapping it back in later.
6528 This can be used to greatly speedup the startup of GDB by using a
6529 pre-parsed symbol table which lives in a mmalloc managed heap. For
6530 more details, please read mmalloc/mmalloc.texi.
6534 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6535 'help info proc' for details.
6537 * MIPS ecoff symbol table format
6539 The code that reads MIPS symbol table format is now supported on all hosts.
6540 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6543 * File name changes for MS-DOS
6545 Many files in the config directories have been renamed to make it easier to
6546 support GDB on MS-DOSe systems (which have very restrictive file name
6547 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6548 environment) is close to working but has some remaining problems. Note
6549 that debugging of DOS programs is not supported, due to limitations
6550 in the ``operating system'', but it can be used to host cross-debugging.
6552 * Cross byte order fixes
6554 Many fixes have been made to support cross debugging of Sparc and MIPS
6555 targets from hosts whose byte order differs.
6557 * New -mapped and -readnow options
6559 If memory-mapped files are available on your system through the 'mmap'
6560 system call, you can use the -mapped option on the `file' or
6561 `symbol-file' commands to cause GDB to write the symbols from your
6562 program into a reusable file. If the program you are debugging is
6563 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6564 Future GDB debugging sessions will notice the presence of this file,
6565 and will quickly map in symbol information from it, rather than reading
6566 the symbol table from the executable program. Using the '-mapped'
6567 option in a GDB `file' or `symbol-file' command has the same effect as
6568 starting GDB with the '-mapped' command-line option.
6570 You can cause GDB to read the entire symbol table immediately by using
6571 the '-readnow' option with any of the commands that load symbol table
6572 information (or on the GDB command line). This makes the command
6573 slower, but makes future operations faster.
6575 The -mapped and -readnow options are typically combined in order to
6576 build a `fred.syms' file that contains complete symbol information.
6577 A simple GDB invocation to do nothing but build a `.syms' file for future
6580 gdb -batch -nx -mapped -readnow programname
6582 The `.syms' file is specific to the host machine on which GDB is run.
6583 It holds an exact image of GDB's internal symbol table. It cannot be
6584 shared across multiple host platforms.
6586 * longjmp() handling
6588 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6589 siglongjmp() without losing control. This feature has not yet been ported to
6590 all systems. It currently works on many 386 platforms, all MIPS-based
6591 platforms (SGI, DECstation, etc), and Sun3/4.
6595 Preliminary work has been put in to support the new Solaris OS from Sun. At
6596 this time, it can control and debug processes, but it is not capable of
6601 As always, many many bug fixes. The major areas were with g++, and mipsread.
6602 People using the MIPS-based platforms should experience fewer mysterious
6603 crashes and trashed symbol tables.
6605 *** Changes in GDB-4.4:
6607 * New machines supported (host and target)
6609 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6611 BSD Reno on Vax vax-dec-bsd
6612 Ultrix on Vax vax-dec-ultrix
6614 * New machines supported (target)
6616 AMD 29000 embedded, using EBMON a29k-none-none
6620 GDB continues to improve its handling of C++. `References' work better.
6621 The demangler has also been improved, and now deals with symbols mangled as
6622 per the Annotated C++ Reference Guide.
6624 GDB also now handles `stabs' symbol information embedded in MIPS
6625 `ecoff' symbol tables. Since the ecoff format was not easily
6626 extensible to handle new languages such as C++, this appeared to be a
6627 good way to put C++ debugging info into MIPS binaries. This option
6628 will be supported in the GNU C compiler, version 2, when it is
6631 * New features for SVR4
6633 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6634 shared libraries. Debugging dynamically linked programs should present
6635 only minor differences from debugging statically linked programs.
6637 The `info proc' command will print out information about any process
6638 on an SVR4 system (including the one you are debugging). At the moment,
6639 it prints the address mappings of the process.
6641 If you bring up GDB on another SVR4 system, please send mail to
6642 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6644 * Better dynamic linking support in SunOS
6646 Reading symbols from shared libraries which contain debugging symbols
6647 now works properly. However, there remain issues such as automatic
6648 skipping of `transfer vector' code during function calls, which
6649 make it harder to debug code in a shared library, than to debug the
6650 same code linked statically.
6654 GDB is now using the latest `getopt' routines from the FSF. This
6655 version accepts the -- prefix for options with long names. GDB will
6656 continue to accept the old forms (-option and +option) as well.
6657 Various single letter abbreviations for options have been explicity
6658 added to the option table so that they won't get overshadowed in the
6659 future by other options that begin with the same letter.
6663 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6664 Many assorted bugs have been handled. Many more remain to be handled.
6665 See the various ChangeLog files (primarily in gdb and bfd) for details.
6668 *** Changes in GDB-4.3:
6670 * New machines supported (host and target)
6672 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6673 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6674 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6676 * Almost SCO Unix support
6678 We had hoped to support:
6679 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6680 (except for core file support), but we discovered very late in the release
6681 that it has problems with process groups that render gdb unusable. Sorry
6682 about that. I encourage people to fix it and post the fixes.
6684 * Preliminary ELF and DWARF support
6686 GDB can read ELF object files on System V Release 4, and can handle
6687 debugging records for C, in DWARF format, in ELF files. This support
6688 is preliminary. If you bring up GDB on another SVR4 system, please
6689 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6694 GDB now uses the latest `readline' library. One user-visible change
6695 is that two tabs will list possible command completions, which previously
6696 required typing M-? (meta-question mark, or ESC ?).
6700 The `stepi' bug that many of you noticed has been squashed.
6701 Many bugs in C++ have been handled. Many more remain to be handled.
6702 See the various ChangeLog files (primarily in gdb and bfd) for details.
6704 * State of the MIPS world (in case you wondered):
6706 GDB can understand the symbol tables emitted by the compilers
6707 supplied by most vendors of MIPS-based machines, including DEC. These
6708 symbol tables are in a format that essentially nobody else uses.
6710 Some versions of gcc come with an assembler post-processor called
6711 mips-tfile. This program is required if you want to do source-level
6712 debugging of gcc-compiled programs. I believe FSF does not ship
6713 mips-tfile with gcc version 1, but it will eventually come with gcc
6716 Debugging of g++ output remains a problem. g++ version 1.xx does not
6717 really support it at all. (If you're lucky, you should be able to get
6718 line numbers and stack traces to work, but no parameters or local
6719 variables.) With some work it should be possible to improve the
6722 When gcc version 2 is released, you will have somewhat better luck.
6723 However, even then you will get confusing results for inheritance and
6726 We will eventually provide full debugging of g++ output on
6727 DECstations. This will probably involve some kind of stabs-in-ecoff
6728 encapulation, but the details have not been worked out yet.
6731 *** Changes in GDB-4.2:
6733 * Improved configuration
6735 Only one copy of `configure' exists now, and it is not self-modifying.
6736 Porting BFD is simpler.
6740 The `step' and `next' commands now only stop at the first instruction
6741 of a source line. This prevents the multiple stops that used to occur
6742 in switch statements, for-loops, etc. `Step' continues to stop if a
6743 function that has debugging information is called within the line.
6747 Lots of small bugs fixed. More remain.
6749 * New host supported (not target)
6751 Intel 386 PC clone running Mach i386-none-mach
6754 *** Changes in GDB-4.1:
6756 * Multiple source language support
6758 GDB now has internal scaffolding to handle several source languages.
6759 It determines the type of each source file from its filename extension,
6760 and will switch expression parsing and number formatting to match the
6761 language of the function in the currently selected stack frame.
6762 You can also specifically set the language to be used, with
6763 `set language c' or `set language modula-2'.
6767 GDB now has preliminary support for the GNU Modula-2 compiler,
6768 currently under development at the State University of New York at
6769 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6770 continue through the fall of 1991 and into 1992.
6772 Other Modula-2 compilers are currently not supported, and attempting to
6773 debug programs compiled with them will likely result in an error as the
6774 symbol table is read. Feel free to work on it, though!
6776 There are hooks in GDB for strict type checking and range checking,
6777 in the `Modula-2 philosophy', but they do not currently work.
6781 GDB can now write to executable and core files (e.g. patch
6782 a variable's value). You must turn this switch on, specify
6783 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6784 by assigning a new value to a variable. Modifications take
6787 * Automatic SunOS shared library reading
6789 When you run your program, GDB automatically determines where its
6790 shared libraries (if any) have been loaded, and reads their symbols.
6791 The `share' command is no longer needed. This also works when
6792 examining core files.
6796 You can specify the number of lines that the `list' command shows.
6799 * New machines supported (host and target)
6801 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6802 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6803 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6805 * New hosts supported (not targets)
6807 IBM RT/PC: romp-ibm-aix or rtpc
6809 * New targets supported (not hosts)
6811 AMD 29000 embedded with COFF a29k-none-coff
6812 AMD 29000 embedded with a.out a29k-none-aout
6813 Ultracomputer remote kernel debug a29k-nyu-kern
6815 * New remote interfaces
6821 *** Changes in GDB-4.0:
6825 Wide output is wrapped at good places to make the output more readable.
6827 Gdb now supports cross-debugging from a host machine of one type to a
6828 target machine of another type. Communication with the target system
6829 is over serial lines. The ``target'' command handles connecting to the
6830 remote system; the ``load'' command will download a program into the
6831 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6832 also supports debugging of realtime processes running under VxWorks,
6833 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6834 stub on the target system.
6836 New CPUs supported include the AMD 29000 and Intel 960.
6838 GDB now reads object files and symbol tables via a ``binary file''
6839 library, which allows a single copy of GDB to debug programs of multiple
6840 object file types such as a.out and coff.
6842 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6843 refcard.dvi and refcard.ps are available to format it).
6846 * Control-Variable user interface simplified
6848 All variables that control the operation of the debugger can be set
6849 by the ``set'' command, and displayed by the ``show'' command.
6851 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6852 ``Show prompt'' produces the response:
6853 Gdb's prompt is new-gdb=>.
6855 What follows are the NEW set commands. The command ``help set'' will
6856 print a complete list of old and new set commands. ``help set FOO''
6857 will give a longer description of the variable FOO. ``show'' will show
6858 all of the variable descriptions and their current settings.
6860 confirm on/off: Enables warning questions for operations that are
6861 hard to recover from, e.g. rerunning the program while
6862 it is already running. Default is ON.
6864 editing on/off: Enables EMACS style command line editing
6865 of input. Previous lines can be recalled with
6866 control-P, the current line can be edited with control-B,
6867 you can search for commands with control-R, etc.
6870 history filename NAME: NAME is where the gdb command history
6871 will be stored. The default is .gdb_history,
6872 or the value of the environment variable
6875 history size N: The size, in commands, of the command history. The
6876 default is 256, or the value of the environment variable
6879 history save on/off: If this value is set to ON, the history file will
6880 be saved after exiting gdb. If set to OFF, the
6881 file will not be saved. The default is OFF.
6883 history expansion on/off: If this value is set to ON, then csh-like
6884 history expansion will be performed on
6885 command line input. The default is OFF.
6887 radix N: Sets the default radix for input and output. It can be set
6888 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6889 in the current radix, so "set radix 10" is always a no-op.
6891 height N: This integer value is the number of lines on a page. Default
6892 is 24, the current `stty rows'' setting, or the ``li#''
6893 setting from the termcap entry matching the environment
6896 width N: This integer value is the number of characters on a line.
6897 Default is 80, the current `stty cols'' setting, or the ``co#''
6898 setting from the termcap entry matching the environment
6901 Note: ``set screensize'' is obsolete. Use ``set height'' and
6902 ``set width'' instead.
6904 print address on/off: Print memory addresses in various command displays,
6905 such as stack traces and structure values. Gdb looks
6906 more ``symbolic'' if you turn this off; it looks more
6907 ``machine level'' with it on. Default is ON.
6909 print array on/off: Prettyprint arrays. New convenient format! Default
6912 print demangle on/off: Print C++ symbols in "source" form if on,
6915 print asm-demangle on/off: Same, for assembler level printouts
6918 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6921 * Support for Epoch Environment.
6923 The epoch environment is a version of Emacs v18 with windowing. One
6924 new command, ``inspect'', is identical to ``print'', except that if you
6925 are running in the epoch environment, the value is printed in its own
6929 * Support for Shared Libraries
6931 GDB can now debug programs and core files that use SunOS shared libraries.
6932 Symbols from a shared library cannot be referenced
6933 before the shared library has been linked with the program (this
6934 happens after you type ``run'' and before the function main() is entered).
6935 At any time after this linking (including when examining core files
6936 from dynamically linked programs), gdb reads the symbols from each
6937 shared library when you type the ``sharedlibrary'' command.
6938 It can be abbreviated ``share''.
6940 sharedlibrary REGEXP: Load shared object library symbols for files
6941 matching a unix regular expression. No argument
6942 indicates to load symbols for all shared libraries.
6944 info sharedlibrary: Status of loaded shared libraries.
6949 A watchpoint stops execution of a program whenever the value of an
6950 expression changes. Checking for this slows down execution
6951 tremendously whenever you are in the scope of the expression, but is
6952 quite useful for catching tough ``bit-spreader'' or pointer misuse
6953 problems. Some machines such as the 386 have hardware for doing this
6954 more quickly, and future versions of gdb will use this hardware.
6956 watch EXP: Set a watchpoint (breakpoint) for an expression.
6958 info watchpoints: Information about your watchpoints.
6960 delete N: Deletes watchpoint number N (same as breakpoints).
6961 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6962 enable N: Re-enables watchpoint number N (same as breakpoints).
6965 * C++ multiple inheritance
6967 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6970 * C++ exception handling
6972 Gdb now supports limited C++ exception handling. Besides the existing
6973 ability to breakpoint on an exception handler, gdb can breakpoint on
6974 the raising of an exception (before the stack is peeled back to the
6977 catch FOO: If there is a FOO exception handler in the dynamic scope,
6978 set a breakpoint to catch exceptions which may be raised there.
6979 Multiple exceptions (``catch foo bar baz'') may be caught.
6981 info catch: Lists all exceptions which may be caught in the
6982 current stack frame.
6985 * Minor command changes
6987 The command ``call func (arg, arg, ...)'' now acts like the print
6988 command, except it does not print or save a value if the function's result
6989 is void. This is similar to dbx usage.
6991 The ``up'' and ``down'' commands now always print the frame they end up
6992 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6993 frames without printing.
6995 * New directory command
6997 'dir' now adds directories to the FRONT of the source search path.
6998 The path starts off empty. Source files that contain debug information
6999 about the directory in which they were compiled can be found even
7000 with an empty path; Sun CC and GCC include this information. If GDB can't
7001 find your source file in the current directory, type "dir .".
7003 * Configuring GDB for compilation
7005 For normal use, type ``./configure host''. See README or gdb.texinfo
7008 GDB now handles cross debugging. If you are remotely debugging between
7009 two different machines, type ``./configure host -target=targ''.
7010 Host is the machine where GDB will run; targ is the machine
7011 where the program that you are debugging will run.