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.
36 RiscV ELF riscv*-*-elf
38 * Removed targets and native configurations
40 m88k running OpenBSD m88*-*-openbsd*
41 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
42 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
43 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
45 * Aarch64/Linux hardware watchpoints improvements
47 Hardware watchpoints on unaligned addresses are now properly
48 supported when running Linux kernel 4.10 or higher: read and access
49 watchpoints are no longer spuriously missed, and all watchpoints
50 lengths between 1 and 8 bytes are supported. On older kernels,
51 watchpoints set on unaligned addresses are no longer missed, with
52 the tradeoff that there is a possibility of false hits being
55 *** Changes in GDB 8.1
57 * GDB now supports dynamically creating arbitrary register groups specified
58 in XML target descriptions. This allows for finer grain grouping of
59 registers on systems with a large amount of registers.
61 * The 'ptype' command now accepts a '/o' flag, which prints the
62 offsets and sizes of fields in a struct, like the pahole(1) tool.
64 * New "--readnever" command line option instructs GDB to not read each
65 symbol file's symbolic debug information. This makes startup faster
66 but at the expense of not being able to perform symbolic debugging.
67 This option is intended for use cases where symbolic debugging will
68 not be used, e.g., when you only need to dump the debuggee's core.
70 * GDB now uses the GNU MPFR library, if available, to emulate target
71 floating-point arithmetic during expression evaluation when the target
72 uses different floating-point formats than the host. At least version
73 3.1 of GNU MPFR is required.
75 * GDB now supports access to the guarded-storage-control registers and the
76 software-based guarded-storage broadcast control registers on IBM z14.
78 * On Unix systems, GDB now supports transmitting environment variables
79 that are to be set or unset to GDBserver. These variables will
80 affect the environment to be passed to the remote inferior.
82 To inform GDB of environment variables that are to be transmitted to
83 GDBserver, use the "set environment" command. Only user set
84 environment variables are sent to GDBserver.
86 To inform GDB of environment variables that are to be unset before
87 the remote inferior is started by the GDBserver, use the "unset
90 * Completion improvements
92 ** GDB can now complete function parameters in linespecs and
93 explicit locations without quoting. When setting breakpoints,
94 quoting around functions names to help with TAB-completion is
95 generally no longer necessary. For example, this now completes
98 (gdb) b function(in[TAB]
101 Related, GDB is no longer confused with completing functions in
102 C++ anonymous namespaces:
105 (gdb) b (anonymous namespace)::[TAB][TAB]
106 (anonymous namespace)::a_function()
107 (anonymous namespace)::b_function()
109 ** GDB now has much improved linespec and explicit locations TAB
110 completion support, that better understands what you're
111 completing and offers better suggestions. For example, GDB no
112 longer offers data symbols as possible completions when you're
113 setting a breakpoint.
115 ** GDB now TAB-completes label symbol names.
117 ** The "complete" command now mimics TAB completion accurately.
119 * New command line options (gcore)
122 Dump all memory mappings.
124 * Breakpoints on C++ functions are now set on all scopes by default
126 By default, breakpoints on functions/methods are now interpreted as
127 specifying all functions with the given name ignoring missing
128 leading scopes (namespaces and classes).
130 For example, assuming a C++ program with symbols named:
135 both commands "break func()" and "break B::func()" set a breakpoint
138 You can use the new flag "-qualified" to override this. This makes
139 GDB interpret the specified function name as a complete
140 fully-qualified name instead. For example, using the same C++
141 program, the "break -q B::func" command sets a breakpoint on
142 "B::func", only. A parameter has been added to the Python
143 gdb.Breakpoint constructor to achieve the same result when creating
144 a breakpoint from Python.
146 * Breakpoints on functions marked with C++ ABI tags
148 GDB can now set breakpoints on functions marked with C++ ABI tags
149 (e.g., [abi:cxx11]). See here for a description of ABI tags:
150 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
152 Functions with a C++11 abi tag are demangled/displayed like this:
154 function[abi:cxx11](int)
157 You can now set a breakpoint on such functions simply as if they had
160 (gdb) b function(int)
162 Or if you need to disambiguate between tags, like:
164 (gdb) b function[abi:other_tag](int)
166 Tab completion was adjusted accordingly as well.
170 ** New events gdb.new_inferior, gdb.inferior_deleted, and
171 gdb.new_thread are emitted. See the manual for further
172 description of these.
174 ** A new function, "gdb.rbreak" has been added to the Python API.
175 This function allows the setting of a large number of breakpoints
176 via a regex pattern in Python. See the manual for further details.
178 ** Python breakpoints can now accept explicit locations. See the
179 manual for a further description of this feature.
182 * New features in the GDB remote stub, GDBserver
184 ** GDBserver is now able to start inferior processes with a
185 specified initial working directory.
187 The user can set the desired working directory to be used from
188 GDB using the new "set cwd" command.
190 ** New "--selftest" command line option runs some GDBserver self
191 tests. These self tests are disabled in releases.
193 ** On Unix systems, GDBserver now does globbing expansion and variable
194 substitution in inferior command line arguments.
196 This is done by starting inferiors using a shell, like GDB does.
197 See "set startup-with-shell" in the user manual for how to disable
198 this from GDB when using "target extended-remote". When using
199 "target remote", you can disable the startup with shell by using the
200 new "--no-startup-with-shell" GDBserver command line option.
202 ** On Unix systems, GDBserver now supports receiving environment
203 variables that are to be set or unset from GDB. These variables
204 will affect the environment to be passed to the inferior.
206 * When catching an Ada exception raised with a message, GDB now prints
207 the message in the catchpoint hit notification. In GDB/MI mode, that
208 information is provided as an extra field named "exception-message"
209 in the *stopped notification.
211 * Trait objects can now be inspected When debugging Rust code. This
212 requires compiler support which will appear in Rust 1.24.
216 QEnvironmentHexEncoded
217 Inform GDBserver of an environment variable that is to be passed to
218 the inferior when starting it.
221 Inform GDBserver of an environment variable that is to be unset
222 before starting the remote inferior.
225 Inform GDBserver that the environment should be reset (i.e.,
226 user-set environment variables should be unset).
229 Indicates whether the inferior must be started with a shell or not.
232 Tell GDBserver that the inferior to be started should use a specific
235 * The "maintenance print c-tdesc" command now takes an optional
236 argument which is the file name of XML target description.
238 * The "maintenance selftest" command now takes an optional argument to
239 filter the tests to be run.
241 * The "enable", and "disable" commands now accept a range of
242 breakpoint locations, e.g. "enable 1.3-5".
247 Set and show the current working directory for the inferior.
250 Set and show compilation command used for compiling and injecting code
251 with the 'compile' commands.
253 set debug separate-debug-file
254 show debug separate-debug-file
255 Control the display of debug output about separate debug file search.
257 set dump-excluded-mappings
258 show dump-excluded-mappings
259 Control whether mappings marked with the VM_DONTDUMP flag should be
260 dumped when generating a core file.
263 List the registered selftests.
266 Start the debugged program stopping at the first instruction.
269 Control display of debugging messages related to OpenRISC targets.
271 set|show print type nested-type-limit
272 Set and show the limit of nesting level for nested types that the
273 type printer will show.
275 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
278 * Safer/improved support for debugging with no debug info
280 GDB no longer assumes functions with no debug information return
283 This means that GDB now refuses to call such functions unless you
284 tell it the function's type, by either casting the call to the
285 declared return type, or by casting the function to a function
286 pointer of the right type, and calling that:
288 (gdb) p getenv ("PATH")
289 'getenv' has unknown return type; cast the call to its declared return type
290 (gdb) p (char *) getenv ("PATH")
291 $1 = 0x7fffffffe "/usr/local/bin:/"...
292 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
293 $2 = 0x7fffffffe "/usr/local/bin:/"...
295 Similarly, GDB no longer assumes that global variables with no debug
296 info have type 'int', and refuses to print the variable's value
297 unless you tell it the variable's type:
300 'var' has unknown type; cast it to its declared type
304 * New native configurations
306 FreeBSD/aarch64 aarch64*-*-freebsd*
307 FreeBSD/arm arm*-*-freebsd*
311 FreeBSD/aarch64 aarch64*-*-freebsd*
312 FreeBSD/arm arm*-*-freebsd*
313 OpenRISC ELF or1k*-*-elf
315 * Removed targets and native configurations
317 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
319 *** Changes in GDB 8.0
321 * GDB now supports access to the PKU register on GNU/Linux. The register is
322 added by the Memory Protection Keys for Userspace feature which will be
323 available in future Intel CPUs.
325 * GDB now supports C++11 rvalue references.
329 ** New functions to start, stop and access a running btrace recording.
330 ** Rvalue references are now supported in gdb.Type.
332 * GDB now supports recording and replaying rdrand and rdseed Intel 64
335 * Building GDB and GDBserver now requires a C++11 compiler.
337 For example, GCC 4.8 or later.
339 It is no longer possible to build GDB or GDBserver with a C
340 compiler. The --disable-build-with-cxx configure option has been
343 * Building GDB and GDBserver now requires GNU make >= 3.81.
345 It is no longer supported to build GDB or GDBserver with another
346 implementation of the make program or an earlier version of GNU make.
348 * Native debugging on MS-Windows supports command-line redirection
350 Command-line arguments used for starting programs on MS-Windows can
351 now include redirection symbols supported by native Windows shells,
352 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
353 as "run", "start", and "set args", as well as the corresponding MI
356 * Support for thread names on MS-Windows.
358 GDB now catches and handles the special exception that programs
359 running on MS-Windows use to assign names to threads in the
362 * Support for Java programs compiled with gcj has been removed.
364 * User commands now accept an unlimited number of arguments.
365 Previously, only up to 10 was accepted.
367 * The "eval" command now expands user-defined command arguments.
369 This makes it easier to process a variable number of arguments:
374 eval "print $arg%d", $i
379 * Target descriptions can now describe registers for sparc32 and sparc64.
381 * GDB now supports DWARF version 5 (debug information format).
382 Its .debug_names index is not yet supported.
384 * New native configurations
386 FreeBSD/mips mips*-*-freebsd
390 Synopsys ARC arc*-*-elf32
391 FreeBSD/mips mips*-*-freebsd
393 * Removed targets and native configurations
395 Alpha running FreeBSD alpha*-*-freebsd*
396 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
401 Erases all the flash memory regions reported by the target.
403 maint print arc arc-instruction address
404 Print internal disassembler information about instruction at a given address.
408 set disassembler-options
409 show disassembler-options
410 Controls the passing of target specific information to the disassembler.
411 If it is necessary to specify more than one disassembler option then
412 multiple options can be placed together into a comma separated list.
413 The default value is the empty string. Currently, the only supported
414 targets are ARM, PowerPC and S/390.
419 Erases all the flash memory regions reported by the target. This is
420 equivalent to the CLI command flash-erase.
422 -file-list-shared-libraries
423 List the shared libraries in the program. This is
424 equivalent to the CLI command "info shared".
427 Catchpoints stopping the program when Ada exceptions are
428 handled. This is equivalent to the CLI command "catch handlers".
430 *** Changes in GDB 7.12
432 * GDB and GDBserver now build with a C++ compiler by default.
434 The --enable-build-with-cxx configure option is now enabled by
435 default. One must now explicitly configure with
436 --disable-build-with-cxx in order to build with a C compiler. This
437 option will be removed in a future release.
439 * GDBserver now supports recording btrace without maintaining an active
442 * GDB now supports a negative repeat count in the 'x' command to examine
443 memory backward from the given address. For example:
446 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
447 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
448 (gdb) x/-5i 0x0000000000400580
449 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
450 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
451 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
452 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
453 0x40057b <main(int, char**)+25>:
454 callq 0x400536 <Func1(int, char const*)>
456 * Fortran: Support structures with fields of dynamic types and
457 arrays of dynamic types.
459 * The symbol dumping maintenance commands have new syntax.
460 maint print symbols [-pc address] [--] [filename]
461 maint print symbols [-objfile objfile] [-source source] [--] [filename]
462 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
463 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
464 maint print msymbols [-objfile objfile] [--] [filename]
466 * GDB now supports multibit bitfields and enums in target register
469 * New Python-based convenience function $_as_string(val), which returns
470 the textual representation of a value. This function is especially
471 useful to obtain the text label of an enum value.
473 * Intel MPX bound violation handling.
475 Segmentation faults caused by a Intel MPX boundary violation
476 now display the kind of violation (upper or lower), the memory
477 address accessed and the memory bounds, along with the usual
478 signal received and code location.
482 Program received signal SIGSEGV, Segmentation fault
483 Upper bound violation while accessing address 0x7fffffffc3b3
484 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
485 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
487 * Rust language support.
488 GDB now supports debugging programs written in the Rust programming
489 language. See https://www.rust-lang.org/ for more information about
492 * Support for running interpreters on specified input/output devices
494 GDB now supports a new mechanism that allows frontends to provide
495 fully featured GDB console views, as a better alternative to
496 building such views on top of the "-interpreter-exec console"
497 command. See the new "new-ui" command below. With that command,
498 frontends can now start GDB in the traditional command-line mode
499 running in an embedded terminal emulator widget, and create a
500 separate MI interpreter running on a specified i/o device. In this
501 way, GDB handles line editing, history, tab completion, etc. in the
502 console all by itself, and the GUI uses the separate MI interpreter
503 for its own control and synchronization, invisible to the command
506 * The "catch syscall" command catches groups of related syscalls.
508 The "catch syscall" command now supports catching a group of related
509 syscalls using the 'group:' or 'g:' prefix.
514 skip -gfile file-glob-pattern
515 skip -function function
516 skip -rfunction regular-expression
517 A generalized form of the skip command, with new support for
518 glob-style file names and regular expressions for function names.
519 Additionally, a file spec and a function spec may now be combined.
521 maint info line-table REGEXP
522 Display the contents of GDB's internal line table data struture.
525 Run any GDB unit tests that were compiled in.
528 Start a new user interface instance running INTERP as interpreter,
529 using the TTY file for input/output.
533 ** gdb.Breakpoint objects have a new attribute "pending", which
534 indicates whether the breakpoint is pending.
535 ** Three new breakpoint-related events have been added:
536 gdb.breakpoint_created, gdb.breakpoint_modified, and
537 gdb.breakpoint_deleted.
540 Signal ("set") the given MS-Windows event object. This is used in
541 conjunction with the Windows JIT debugging (AeDebug) support, where
542 the OS suspends a crashing process until a debugger can attach to
543 it. Resuming the crashing process, in order to debug it, is done by
546 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
547 was added in GDBserver, including JIT compiling fast tracepoint's
548 conditional expression bytecode into native code.
550 * Support for various remote target protocols and ROM monitors has
553 target m32rsdi Remote M32R debugging over SDI
554 target mips MIPS remote debugging protocol
555 target pmon PMON ROM monitor
556 target ddb NEC's DDB variant of PMON for Vr4300
557 target rockhopper NEC RockHopper variant of PMON
558 target lsi LSI variant of PMO
560 * Support for tracepoints and fast tracepoints on powerpc-linux,
561 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
562 including JIT compiling fast tracepoint's conditional expression
563 bytecode into native code.
565 * MI async record =record-started now includes the method and format used for
566 recording. For example:
568 =record-started,thread-group="i1",method="btrace",format="bts"
570 * MI async record =thread-selected now includes the frame field. For example:
572 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
576 Andes NDS32 nds32*-*-elf
578 *** Changes in GDB 7.11
580 * GDB now supports debugging kernel-based threads on FreeBSD.
582 * Per-inferior thread numbers
584 Thread numbers are now per inferior instead of global. If you're
585 debugging multiple inferiors, GDB displays thread IDs using a
586 qualified INF_NUM.THR_NUM form. For example:
590 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
591 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
592 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
593 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
595 As consequence, thread numbers as visible in the $_thread
596 convenience variable and in Python's InferiorThread.num attribute
597 are no longer unique between inferiors.
599 GDB now maintains a second thread ID per thread, referred to as the
600 global thread ID, which is the new equivalent of thread numbers in
601 previous releases. See also $_gthread below.
603 For backwards compatibility, MI's thread IDs always refer to global
606 * Commands that accept thread IDs now accept the qualified
607 INF_NUM.THR_NUM form as well. For example:
610 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
613 * In commands that accept a list of thread IDs, you can now refer to
614 all threads of an inferior using a star wildcard. GDB accepts
615 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
616 refer to all threads of the current inferior. For example, "info
619 * You can use "info threads -gid" to display the global thread ID of
622 * The new convenience variable $_gthread holds the global number of
625 * The new convenience variable $_inferior holds the number of the
628 * GDB now displays the ID and name of the thread that hit a breakpoint
629 or received a signal, if your program is multi-threaded. For
632 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
633 Thread 1 "main" received signal SIGINT, Interrupt.
635 * Record btrace now supports non-stop mode.
637 * Support for tracepoints on aarch64-linux was added in GDBserver.
639 * The 'record instruction-history' command now indicates speculative execution
640 when using the Intel Processor Trace recording format.
642 * GDB now allows users to specify explicit locations, bypassing
643 the linespec parser. This feature is also available to GDB/MI
646 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
647 GDB now is able to debug both AArch64 applications and ARM applications
650 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
651 including JIT compiling fast tracepoint's conditional expression bytecode
654 * GDB now supports displaced stepping on AArch64 GNU/Linux.
656 * "info threads", "info inferiors", "info display", "info checkpoints"
657 and "maint info program-spaces" now list the corresponding items in
658 ascending ID order, for consistency with all other "info" commands.
660 * In Ada, the overloads selection menu has been enhanced to display the
661 parameter types and the return types for the matching overloaded subprograms.
665 maint set target-non-stop (on|off|auto)
666 maint show target-non-stop
667 Control whether GDB targets always operate in non-stop mode even if
668 "set non-stop" is "off". The default is "auto", meaning non-stop
669 mode is enabled if supported by the target.
671 maint set bfd-sharing
672 maint show bfd-sharing
673 Control the reuse of bfd objects.
677 Control display of debugging info regarding bfd caching.
681 Control display of debugging info regarding FreeBSD threads.
683 set remote multiprocess-extensions-packet
684 show remote multiprocess-extensions-packet
685 Set/show the use of the remote protocol multiprocess extensions.
687 set remote thread-events
688 show remote thread-events
689 Set/show the use of thread create/exit events.
691 set ada print-signatures on|off
692 show ada print-signatures"
693 Control whether parameter types and return types are displayed in overloads
694 selection menus. It is activaled (@code{on}) by default.
698 Controls the maximum size of memory, in bytes, that GDB will
699 allocate for value contents. Prevents incorrect programs from
700 causing GDB to allocate overly large buffers. Default is 64k.
702 * The "disassemble" command accepts a new modifier: /s.
703 It prints mixed source+disassembly like /m with two differences:
704 - disassembled instructions are now printed in program order, and
705 - and source for all relevant files is now printed.
706 The "/m" option is now considered deprecated: its "source-centric"
707 output hasn't proved useful in practice.
709 * The "record instruction-history" command accepts a new modifier: /s.
710 It behaves exactly like /m and prints mixed source+disassembly.
712 * The "set scheduler-locking" command supports a new mode "replay".
713 It behaves like "off" in record mode and like "on" in replay mode.
715 * Support for various ROM monitors has been removed:
717 target dbug dBUG ROM monitor for Motorola ColdFire
718 target picobug Motorola picobug monitor
719 target dink32 DINK32 ROM monitor for PowerPC
720 target m32r Renesas M32R/D ROM monitor
721 target mon2000 mon2000 ROM monitor
722 target ppcbug PPCBUG ROM monitor for PowerPC
724 * Support for reading/writing memory and extracting values on architectures
725 whose memory is addressable in units of any integral multiple of 8 bits.
728 Allows to break when an Ada exception is handled.
733 Indicates that an exec system call was executed.
735 exec-events feature in qSupported
736 The qSupported packet allows GDB to request support for exec
737 events using the new 'gdbfeature' exec-event, and the qSupported
738 response can contain the corresponding 'stubfeature'. Set and
739 show commands can be used to display whether these features are enabled.
742 Equivalent to interrupting with the ^C character, but works in
745 thread created stop reason (T05 create:...)
746 Indicates that the thread was just created and is stopped at entry.
748 thread exit stop reply (w exitcode;tid)
749 Indicates that the thread has terminated.
752 Enables/disables thread create and exit event reporting. For
753 example, this is used in non-stop mode when GDB stops a set of
754 threads and synchronously waits for the their corresponding stop
755 replies. Without exit events, if one of the threads exits, GDB
756 would hang forever not knowing that it should no longer expect a
757 stop for that same thread.
760 Indicates that there are no resumed threads left in the target (all
761 threads are stopped). The remote stub reports support for this stop
762 reply to GDB's qSupported query.
765 Enables/disables catching syscalls from the inferior process.
766 The remote stub reports support for this packet to GDB's qSupported query.
768 syscall_entry stop reason
769 Indicates that a syscall was just called.
771 syscall_return stop reason
772 Indicates that a syscall just returned.
774 * Extended-remote exec events
776 ** GDB now has support for exec events on extended-remote Linux targets.
777 For such targets with Linux kernels 2.5.46 and later, this enables
778 follow-exec-mode and exec catchpoints.
780 set remote exec-event-feature-packet
781 show remote exec-event-feature-packet
782 Set/show the use of the remote exec event feature.
784 * Thread names in remote protocol
786 The reply to qXfer:threads:read may now include a name attribute for each
789 * Target remote mode fork and exec events
791 ** GDB now has support for fork and exec events on target remote mode
792 Linux targets. For such targets with Linux kernels 2.5.46 and later,
793 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
794 fork and exec catchpoints.
796 * Remote syscall events
798 ** GDB now has support for catch syscall on remote Linux targets,
799 currently enabled on x86/x86_64 architectures.
801 set remote catch-syscall-packet
802 show remote catch-syscall-packet
803 Set/show the use of the remote catch syscall feature.
807 ** The -var-set-format command now accepts the zero-hexadecimal
808 format. It outputs data in hexadecimal format with zero-padding on the
813 ** gdb.InferiorThread objects have a new attribute "global_num",
814 which refers to the thread's global thread ID. The existing
815 "num" attribute now refers to the thread's per-inferior number.
816 See "Per-inferior thread numbers" above.
817 ** gdb.InferiorThread objects have a new attribute "inferior", which
818 is the Inferior object the thread belongs to.
820 *** Changes in GDB 7.10
822 * Support for process record-replay and reverse debugging on aarch64*-linux*
823 targets has been added. GDB now supports recording of A64 instruction set
824 including advance SIMD instructions.
826 * Support for Sun's version of the "stabs" debug file format has been removed.
828 * GDB now honors the content of the file /proc/PID/coredump_filter
829 (PID is the process ID) on GNU/Linux systems. This file can be used
830 to specify the types of memory mappings that will be included in a
831 corefile. For more information, please refer to the manual page of
832 "core(5)". GDB also has a new command: "set use-coredump-filter
833 on|off". It allows to set whether GDB will read the content of the
834 /proc/PID/coredump_filter file when generating a corefile.
836 * The "info os" command on GNU/Linux can now display information on
838 "info os cpus" Listing of all cpus/cores on the system
840 * GDB has two new commands: "set serial parity odd|even|none" and
841 "show serial parity". These allows to set or show parity for the
844 * The "info source" command now displays the producer string if it was
845 present in the debug info. This typically includes the compiler version
846 and may include things like its command line arguments.
848 * The "info dll", an alias of the "info sharedlibrary" command,
849 is now available on all platforms.
851 * Directory names supplied to the "set sysroot" commands may be
852 prefixed with "target:" to tell GDB to access shared libraries from
853 the target system, be it local or remote. This replaces the prefix
854 "remote:". The default sysroot has been changed from "" to
855 "target:". "remote:" is automatically converted to "target:" for
856 backward compatibility.
858 * The system root specified by "set sysroot" will be prepended to the
859 filename of the main executable (if reported to GDB as absolute by
860 the operating system) when starting processes remotely, and when
861 attaching to already-running local or remote processes.
863 * GDB now supports automatic location and retrieval of executable
864 files from remote targets. Remote debugging can now be initiated
865 using only a "target remote" or "target extended-remote" command
866 (no "set sysroot" or "file" commands are required). See "New remote
869 * The "dump" command now supports verilog hex format.
871 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
873 * On GNU/Linux, GDB and gdbserver are now able to access executable
874 and shared library files without a "set sysroot" command when
875 attaching to processes running in different mount namespaces from
876 the debugger. This makes it possible to attach to processes in
877 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
878 See "New remote packets" below.
880 * The "tui reg" command now provides completion for all of the
881 available register groups, including target specific groups.
883 * The HISTSIZE environment variable is no longer read when determining
884 the size of GDB's command history. GDB now instead reads the dedicated
885 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
886 disables truncation of command history. Non-numeric values of GDBHISTSIZE
891 ** Memory ports can now be unbuffered.
895 ** gdb.Objfile objects have a new attribute "username",
896 which is the name of the objfile as specified by the user,
897 without, for example, resolving symlinks.
898 ** You can now write frame unwinders in Python.
899 ** gdb.Type objects have a new method "optimized_out",
900 returning optimized out gdb.Value instance of this type.
901 ** gdb.Value objects have new methods "reference_value" and
902 "const_value" which return a reference to the value and a
903 "const" version of the value respectively.
907 maint print symbol-cache
908 Print the contents of the symbol cache.
910 maint print symbol-cache-statistics
911 Print statistics of symbol cache usage.
913 maint flush-symbol-cache
914 Flush the contents of the symbol cache.
918 Start branch trace recording using Branch Trace Store (BTS) format.
921 Evaluate expression by using the compiler and print result.
925 Explicit commands for enabling and disabling tui mode.
928 set mpx bound on i386 and amd64
929 Support for bound table investigation on Intel MPX enabled applications.
933 Start branch trace recording using Intel Processor Trace format.
936 Print information about branch tracing internals.
938 maint btrace packet-history
939 Print the raw branch tracing data.
941 maint btrace clear-packet-history
942 Discard the stored raw branch tracing data.
945 Discard all branch tracing data. It will be fetched and processed
946 anew by the next "record" command.
951 Renamed from "set debug dwarf2-die".
953 Renamed from "show debug dwarf2-die".
956 Renamed from "set debug dwarf2-read".
957 show debug dwarf-read
958 Renamed from "show debug dwarf2-read".
960 maint set dwarf always-disassemble
961 Renamed from "maint set dwarf2 always-disassemble".
962 maint show dwarf always-disassemble
963 Renamed from "maint show dwarf2 always-disassemble".
965 maint set dwarf max-cache-age
966 Renamed from "maint set dwarf2 max-cache-age".
967 maint show dwarf max-cache-age
968 Renamed from "maint show dwarf2 max-cache-age".
971 show debug dwarf-line
972 Control display of debugging info regarding DWARF line processing.
976 Set the maximum number of candidates to be considered during
977 completion. The default value is 200. This limit allows GDB
978 to avoid generating large completion lists, the computation of
979 which can cause the debugger to become temporarily unresponsive.
981 set history remove-duplicates
982 show history remove-duplicates
983 Control the removal of duplicate history entries.
985 maint set symbol-cache-size
986 maint show symbol-cache-size
987 Control the size of the symbol cache.
989 set|show record btrace bts buffer-size
990 Set and show the size of the ring buffer used for branch tracing in
992 The obtained size may differ from the requested size. Use "info
993 record" to see the obtained buffer size.
995 set debug linux-namespaces
996 show debug linux-namespaces
997 Control display of debugging info regarding Linux namespaces.
999 set|show record btrace pt buffer-size
1000 Set and show the size of the ring buffer used for branch tracing in
1001 Intel Processor Trace format.
1002 The obtained size may differ from the requested size. Use "info
1003 record" to see the obtained buffer size.
1005 maint set|show btrace pt skip-pad
1006 Set and show whether PAD packets are skipped when computing the
1009 * The command 'thread apply all' can now support new option '-ascending'
1010 to call its specified command for all threads in ascending order.
1012 * Python/Guile scripting
1014 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1015 special section named `.debug_gdb_scripts'.
1017 * New remote packets
1019 qXfer:btrace-conf:read
1020 Return the branch trace configuration for the current thread.
1022 Qbtrace-conf:bts:size
1023 Set the requested ring buffer size for branch tracing in BTS format.
1026 Enable Intel Procesor Trace-based branch tracing for the current
1027 process. The remote stub reports support for this packet to GDB's
1030 Qbtrace-conf:pt:size
1031 Set the requested ring buffer size for branch tracing in Intel Processor
1035 Indicates a memory breakpoint instruction was executed, irrespective
1036 of whether it was GDB that planted the breakpoint or the breakpoint
1037 is hardcoded in the program. This is required for correct non-stop
1041 Indicates the target stopped for a hardware breakpoint. This is
1042 required for correct non-stop mode operation.
1045 Return information about files on the remote system.
1047 qXfer:exec-file:read
1048 Return the full absolute name of the file that was executed to
1049 create a process running on the remote system.
1052 Select the filesystem on which vFile: operations with filename
1053 arguments will operate. This is required for GDB to be able to
1054 access files on remote targets where the remote stub does not
1055 share a common filesystem with the inferior(s).
1058 Indicates that a fork system call was executed.
1061 Indicates that a vfork system call was executed.
1063 vforkdone stop reason
1064 Indicates that a vfork child of the specified process has executed
1065 an exec or exit, allowing the vfork parent to resume execution.
1067 fork-events and vfork-events features in qSupported
1068 The qSupported packet allows GDB to request support for fork and
1069 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1070 and the qSupported response can contain the corresponding
1071 'stubfeatures'. Set and show commands can be used to display
1072 whether these features are enabled.
1074 * Extended-remote fork events
1076 ** GDB now has support for fork events on extended-remote Linux
1077 targets. For targets with Linux kernels 2.5.60 and later, this
1078 enables follow-fork-mode and detach-on-fork for both fork and
1079 vfork, as well as fork and vfork catchpoints.
1081 * The info record command now shows the recording format and the
1082 branch tracing configuration for the current thread when using
1083 the btrace record target.
1084 For the BTS format, it shows the ring buffer size.
1086 * GDB now has support for DTrace USDT (Userland Static Defined
1087 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1089 * GDB now supports access to vector registers on S/390 GNU/Linux
1092 * Removed command line options
1094 -xdb HP-UX XDB compatibility mode.
1096 * Removed targets and native configurations
1098 HP/PA running HP-UX hppa*-*-hpux*
1099 Itanium running HP-UX ia64-*-hpux*
1101 * New configure options
1104 This configure option allows the user to build GDB with support for
1105 Intel Processor Trace (default: auto). This requires libipt.
1107 --with-libipt-prefix=PATH
1108 Specify the path to the version of libipt that GDB should use.
1109 $PATH/include should contain the intel-pt.h header and
1110 $PATH/lib should contain the libipt.so library.
1112 *** Changes in GDB 7.9.1
1116 ** Xmethods can now specify a result type.
1118 *** Changes in GDB 7.9
1120 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1124 ** You can now access frame registers from Python scripts.
1125 ** New attribute 'producer' for gdb.Symtab objects.
1126 ** gdb.Objfile objects have a new attribute "progspace",
1127 which is the gdb.Progspace object of the containing program space.
1128 ** gdb.Objfile objects have a new attribute "owner".
1129 ** gdb.Objfile objects have a new attribute "build_id",
1130 which is the build ID generated when the file was built.
1131 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1132 ** A new event "gdb.clear_objfiles" has been added, triggered when
1133 selecting a new file to debug.
1134 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1135 ** New function gdb.lookup_objfile.
1137 New events which are triggered when GDB modifies the state of the
1140 ** gdb.events.inferior_call_pre: Function call is about to be made.
1141 ** gdb.events.inferior_call_post: Function call has just been made.
1142 ** gdb.events.memory_changed: A memory location has been altered.
1143 ** gdb.events.register_changed: A register has been altered.
1145 * New Python-based convenience functions:
1147 ** $_caller_is(name [, number_of_frames])
1148 ** $_caller_matches(regexp [, number_of_frames])
1149 ** $_any_caller_is(name [, number_of_frames])
1150 ** $_any_caller_matches(regexp [, number_of_frames])
1152 * GDB now supports the compilation and injection of source code into
1153 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1154 to compile the source code to object code, and if successful, inject
1155 and execute that code within the current context of the inferior.
1156 Currently the C language is supported. The commands used to
1157 interface with this new feature are:
1159 compile code [-raw|-r] [--] [source code]
1160 compile file [-raw|-r] filename
1164 demangle [-l language] [--] name
1165 Demangle "name" in the specified language, or the current language
1166 if elided. This command is renamed from the "maint demangle" command.
1167 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1168 as "maint demangler-warning".
1170 queue-signal signal-name-or-number
1171 Queue a signal to be delivered to the thread when it is resumed.
1173 add-auto-load-scripts-directory directory
1174 Add entries to the list of directories from which to load auto-loaded
1177 maint print user-registers
1178 List all currently available "user" registers.
1180 compile code [-r|-raw] [--] [source code]
1181 Compile, inject, and execute in the inferior the executable object
1182 code produced by compiling the provided source code.
1184 compile file [-r|-raw] filename
1185 Compile and inject into the inferior the executable object code
1186 produced by compiling the source code stored in the filename
1189 * On resume, GDB now always passes the signal the program had stopped
1190 for to the thread the signal was sent to, even if the user changed
1191 threads before resuming. Previously GDB would often (but not
1192 always) deliver the signal to the thread that happens to be current
1195 * Conversely, the "signal" command now consistently delivers the
1196 requested signal to the current thread. GDB now asks for
1197 confirmation if the program had stopped for a signal and the user
1198 switched threads meanwhile.
1200 * "breakpoint always-inserted" modes "off" and "auto" merged.
1202 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1203 won't remove breakpoints from the target until all threads stop,
1204 even in non-stop mode. The "auto" mode has been removed, and "off"
1205 is now the default mode.
1209 set debug symbol-lookup
1210 show debug symbol-lookup
1211 Control display of debugging info regarding symbol lookup.
1215 ** The -list-thread-groups command outputs an exit-code field for
1216 inferiors that have exited.
1220 MIPS SDE mips*-sde*-elf*
1224 Support for these obsolete configurations has been removed.
1226 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1227 SGI Irix-5.x mips-*-irix5*
1228 SGI Irix-6.x mips-*-irix6*
1229 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1230 VAX running Ultrix vax-*-ultrix*
1232 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1233 and "assf"), have been removed. Use the "sharedlibrary" command, or
1234 its alias "share", instead.
1236 *** Changes in GDB 7.8
1238 * New command line options
1241 This is an alias for the --data-directory option.
1243 * GDB supports printing and modifying of variable length automatic arrays
1244 as specified in ISO C99.
1246 * The ARM simulator now supports instruction level tracing
1247 with or without disassembly.
1251 GDB now has support for scripting using Guile. Whether this is
1252 available is determined at configure time.
1253 Guile version 2.0 or greater is required.
1254 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1256 * New commands (for set/show, see "New options" below)
1260 Invoke CODE by passing it to the Guile interpreter.
1264 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1266 info auto-load guile-scripts [regexp]
1267 Print the list of automatically loaded Guile scripts.
1269 * The source command is now capable of sourcing Guile scripts.
1270 This feature is dependent on the debugger being built with Guile support.
1274 set print symbol-loading (off|brief|full)
1275 show print symbol-loading
1276 Control whether to print informational messages when loading symbol
1277 information for a file. The default is "full", but when debugging
1278 programs with large numbers of shared libraries the amount of output
1279 becomes less useful.
1281 set guile print-stack (none|message|full)
1282 show guile print-stack
1283 Show a stack trace when an error is encountered in a Guile script.
1285 set auto-load guile-scripts (on|off)
1286 show auto-load guile-scripts
1287 Control auto-loading of Guile script files.
1289 maint ada set ignore-descriptive-types (on|off)
1290 maint ada show ignore-descriptive-types
1291 Control whether the debugger should ignore descriptive types in Ada
1292 programs. The default is not to ignore the descriptive types. See
1293 the user manual for more details on descriptive types and the intended
1294 usage of this option.
1296 set auto-connect-native-target
1298 Control whether GDB is allowed to automatically connect to the
1299 native target for the run, attach, etc. commands when not connected
1300 to any target yet. See also "target native" below.
1302 set record btrace replay-memory-access (read-only|read-write)
1303 show record btrace replay-memory-access
1304 Control what memory accesses are allowed during replay.
1306 maint set target-async (on|off)
1307 maint show target-async
1308 This controls whether GDB targets operate in synchronous or
1309 asynchronous mode. Normally the default is asynchronous, if it is
1310 available; but this can be changed to more easily debug problems
1311 occurring only in synchronous mode.
1313 set mi-async (on|off)
1315 Control whether MI asynchronous mode is preferred. This supersedes
1316 "set target-async" of previous GDB versions.
1318 * "set target-async" is deprecated as a CLI option and is now an alias
1319 for "set mi-async" (only puts MI into async mode).
1321 * Background execution commands (e.g., "c&", "s&", etc.) are now
1322 possible ``out of the box'' if the target supports them. Previously
1323 the user would need to explicitly enable the possibility with the
1324 "set target-async on" command.
1326 * New features in the GDB remote stub, GDBserver
1328 ** New option --debug-format=option1[,option2,...] allows one to add
1329 additional text to each output. At present only timestamps
1330 are supported: --debug-format=timestamps.
1331 Timestamps can also be turned on with the
1332 "monitor set debug-format timestamps" command from GDB.
1334 * The 'record instruction-history' command now starts counting instructions
1335 at one. This also affects the instruction ranges reported by the
1336 'record function-call-history' command when given the /i modifier.
1338 * The command 'record function-call-history' supports a new modifier '/c' to
1339 indent the function names based on their call stack depth.
1340 The fields for the '/i' and '/l' modifier have been reordered.
1341 The source line range is now prefixed with 'at'.
1342 The instruction range is now prefixed with 'inst'.
1343 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1344 "record instruction-history" and "list" commands.
1346 * The ranges given as arguments to the 'record function-call-history' and
1347 'record instruction-history' commands are now inclusive.
1349 * The btrace record target now supports the 'record goto' command.
1350 For locations inside the execution trace, the back trace is computed
1351 based on the information stored in the execution trace.
1353 * The btrace record target supports limited reverse execution and replay.
1354 The target does not record data and therefore does not allow reading
1355 memory or registers.
1357 * The "catch syscall" command now works on s390*-linux* targets.
1359 * The "compare-sections" command is no longer specific to target
1360 remote. It now works with all targets.
1362 * All native targets are now consistently called "native".
1363 Consequently, the "target child", "target GNU", "target djgpp",
1364 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1365 commands have been replaced with "target native". The QNX/NTO port
1366 leaves the "procfs" target in place and adds a "native" target for
1367 consistency with other ports. The impact on users should be minimal
1368 as these commands previously either throwed an error, or were
1369 no-ops. The target's name is visible in the output of the following
1370 commands: "help target", "info target", "info files", "maint print
1373 * The "target native" command now connects to the native target. This
1374 can be used to launch native programs even when "set
1375 auto-connect-native-target" is set to off.
1377 * GDB now supports access to Intel MPX registers on GNU/Linux.
1379 * Support for Intel AVX-512 registers on GNU/Linux.
1380 Support displaying and modifying Intel AVX-512 registers
1381 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1383 * New remote packets
1385 qXfer:btrace:read's annex
1386 The qXfer:btrace:read packet supports a new annex 'delta' to read
1387 branch trace incrementally.
1391 ** Valid Python operations on gdb.Value objects representing
1392 structs/classes invoke the corresponding overloaded operators if
1394 ** New `Xmethods' feature in the Python API. Xmethods are
1395 additional methods or replacements for existing methods of a C++
1396 class. This feature is useful for those cases where a method
1397 defined in C++ source code could be inlined or optimized out by
1398 the compiler, making it unavailable to GDB.
1401 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1403 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1404 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1405 its alias "share", instead.
1407 * The commands "set remotebaud" and "show remotebaud" are no longer
1408 supported. Use "set serial baud" and "show serial baud" (respectively)
1413 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1414 target-async". The latter is left as a deprecated alias of the
1415 former for backward compatibility. If the target supports it,
1416 CLI background execution commands are now always possible by
1417 default, independently of whether the frontend stated a
1418 preference for asynchronous execution with "-gdb-set mi-async".
1419 Previously "-gdb-set target-async off" affected both MI execution
1420 commands and CLI execution commands.
1422 *** Changes in GDB 7.7
1424 * Improved support for process record-replay and reverse debugging on
1425 arm*-linux* targets. Support for thumb32 and syscall instruction
1426 recording has been added.
1428 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1430 * GDB now supports Fission DWP file format version 2.
1431 http://gcc.gnu.org/wiki/DebugFission
1433 * New convenience function "$_isvoid", to check whether an expression
1434 is void. A void expression is an expression where the type of the
1435 result is "void". For example, some convenience variables may be
1436 "void" when evaluated (e.g., "$_exitcode" before the execution of
1437 the program being debugged; or an undefined convenience variable).
1438 Another example, when calling a function whose return type is
1441 * The "maintenance print objfiles" command now takes an optional regexp.
1443 * The "catch syscall" command now works on arm*-linux* targets.
1445 * GDB now consistently shows "<not saved>" when printing values of
1446 registers the debug info indicates have not been saved in the frame
1447 and there's nowhere to retrieve them from
1448 (callee-saved/call-clobbered registers):
1453 (gdb) info registers rax
1456 Before, the former would print "<optimized out>", and the latter
1457 "*value not available*".
1459 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1464 ** Frame filters and frame decorators have been added.
1465 ** Temporary breakpoints are now supported.
1466 ** Line tables representation has been added.
1467 ** New attribute 'parent_type' for gdb.Field objects.
1468 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1469 ** New attribute 'name' for gdb.Type objects.
1473 Nios II ELF nios2*-*-elf
1474 Nios II GNU/Linux nios2*-*-linux
1475 Texas Instruments MSP430 msp430*-*-elf
1477 * Removed native configurations
1479 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1480 been removed. ELF variants of these configurations are kept supported.
1482 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1483 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1484 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1485 i[34567]86-*-openbsd3.[0-3]
1486 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1487 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1488 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1492 Like "catch throw", but catches a re-thrown exception.
1493 maint check-psymtabs
1494 Renamed from old "maint check-symtabs".
1496 Perform consistency checks on symtabs.
1497 maint expand-symtabs
1498 Expand symtabs matching an optional regexp.
1501 Display the details of GDB configure-time options.
1503 maint set|show per-command
1504 maint set|show per-command space
1505 maint set|show per-command time
1506 maint set|show per-command symtab
1507 Enable display of per-command gdb resource usage.
1509 remove-symbol-file FILENAME
1510 remove-symbol-file -a ADDRESS
1511 Remove a symbol file added via add-symbol-file. The file to remove
1512 can be identified by its filename or by an address that lies within
1513 the boundaries of this symbol file in memory.
1516 info exceptions REGEXP
1517 Display the list of Ada exceptions defined in the program being
1518 debugged. If provided, only the exceptions whose names match REGEXP
1523 set debug symfile off|on
1525 Control display of debugging info regarding reading symbol files and
1526 symbol tables within those files
1528 set print raw frame-arguments
1529 show print raw frame-arguments
1530 Set/show whether to print frame arguments in raw mode,
1531 disregarding any defined pretty-printers.
1533 set remote trace-status-packet
1534 show remote trace-status-packet
1535 Set/show the use of remote protocol qTStatus packet.
1539 Control display of debugging messages related to Nios II targets.
1543 Control whether target-assisted range stepping is enabled.
1545 set startup-with-shell
1546 show startup-with-shell
1547 Specifies whether Unix child processes are started via a shell or
1552 Use the target memory cache for accesses to the code segment. This
1553 improves performance of remote debugging (particularly disassembly).
1555 * You can now use a literal value 'unlimited' for options that
1556 interpret 0 or -1 as meaning "unlimited". E.g., "set
1557 trace-buffer-size unlimited" is now an alias for "set
1558 trace-buffer-size -1" and "set height unlimited" is now an alias for
1561 * The "set debug symtab-create" debugging option of GDB has been changed to
1562 accept a verbosity level. 0 means "off", 1 provides basic debugging
1563 output, and values of 2 or greater provides more verbose output.
1565 * New command-line options
1567 Display the details of GDB configure-time options.
1569 * The command 'tsave' can now support new option '-ctf' to save trace
1570 buffer in Common Trace Format.
1572 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1575 * GDB now implements the the C++ 'typeid' operator.
1577 * The new convenience variable $_exception holds the exception being
1578 thrown or caught at an exception-related catchpoint.
1580 * The exception-related catchpoints, like "catch throw", now accept a
1581 regular expression which can be used to filter exceptions by type.
1583 * The new convenience variable $_exitsignal is automatically set to
1584 the terminating signal number when the program being debugged dies
1585 due to an uncaught signal.
1589 ** All MI commands now accept an optional "--language" option.
1590 Support for this feature can be verified by using the "-list-features"
1591 command, which should contain "language-option".
1593 ** The new command -info-gdb-mi-command allows the user to determine
1594 whether a GDB/MI command is supported or not.
1596 ** The "^error" result record returned when trying to execute an undefined
1597 GDB/MI command now provides a variable named "code" whose content is the
1598 "undefined-command" error code. Support for this feature can be verified
1599 by using the "-list-features" command, which should contain
1600 "undefined-command-error-code".
1602 ** The -trace-save MI command can optionally save trace buffer in Common
1605 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1607 ** The command -data-list-register-values now accepts an optional
1608 "--skip-unavailable" option. When used, only the available registers
1611 ** The new command -trace-frame-collected dumps collected variables,
1612 computed expressions, tvars, memory and registers in a traceframe.
1614 ** The commands -stack-list-locals, -stack-list-arguments and
1615 -stack-list-variables now accept an option "--skip-unavailable".
1616 When used, only the available locals or arguments are displayed.
1618 ** The -exec-run command now accepts an optional "--start" option.
1619 When used, the command follows the same semantics as the "start"
1620 command, stopping the program's execution at the start of its
1621 main subprogram. Support for this feature can be verified using
1622 the "-list-features" command, which should contain
1623 "exec-run-start-option".
1625 ** The new commands -catch-assert and -catch-exceptions insert
1626 catchpoints stopping the program when Ada exceptions are raised.
1628 ** The new command -info-ada-exceptions provides the equivalent of
1629 the new "info exceptions" command.
1631 * New system-wide configuration scripts
1632 A GDB installation now provides scripts suitable for use as system-wide
1633 configuration scripts for the following systems:
1637 * GDB now supports target-assigned range stepping with remote targets.
1638 This improves the performance of stepping source lines by reducing
1639 the number of control packets from/to GDB. See "New remote packets"
1642 * GDB now understands the element 'tvar' in the XML traceframe info.
1643 It has the id of the collected trace state variables.
1645 * On S/390 targets that provide the transactional-execution feature,
1646 the program interruption transaction diagnostic block (TDB) is now
1647 represented as a number of additional "registers" in GDB.
1649 * New remote packets
1653 The vCont packet supports a new 'r' action, that tells the remote
1654 stub to step through an address range itself, without GDB
1655 involvemement at each single-step.
1657 qXfer:libraries-svr4:read's annex
1658 The previously unused annex of the qXfer:libraries-svr4:read packet
1659 is now used to support passing an argument list. The remote stub
1660 reports support for this argument list to GDB's qSupported query.
1661 The defined arguments are "start" and "prev", used to reduce work
1662 necessary for library list updating, resulting in significant
1665 * New features in the GDB remote stub, GDBserver
1667 ** GDBserver now supports target-assisted range stepping. Currently
1668 enabled on x86/x86_64 GNU/Linux targets.
1670 ** GDBserver now adds element 'tvar' in the XML in the reply to
1671 'qXfer:traceframe-info:read'. It has the id of the collected
1672 trace state variables.
1674 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1677 * New 'z' formatter for printing and examining memory, this displays the
1678 value as hexadecimal zero padded on the left to the size of the type.
1680 * GDB can now use Windows x64 unwinding data.
1682 * The "set remotebaud" command has been replaced by "set serial baud".
1683 Similarly, "show remotebaud" has been replaced by "show serial baud".
1684 The "set remotebaud" and "show remotebaud" commands are still available
1685 to provide backward compatibility with older versions of GDB.
1687 *** Changes in GDB 7.6
1689 * Target record has been renamed to record-full.
1690 Record/replay is now enabled with the "record full" command.
1691 This also affects settings that are associated with full record/replay
1692 that have been moved from "set/show record" to "set/show record full":
1694 set|show record full insn-number-max
1695 set|show record full stop-at-limit
1696 set|show record full memory-query
1698 * A new record target "record-btrace" has been added. The new target
1699 uses hardware support to record the control-flow of a process. It
1700 does not support replaying the execution, but it implements the
1701 below new commands for investigating the recorded execution log.
1702 This new recording method can be enabled using:
1706 The "record-btrace" target is only available on Intel Atom processors
1707 and requires a Linux kernel 2.6.32 or later.
1709 * Two new commands have been added for record/replay to give information
1710 about the recorded execution without having to replay the execution.
1711 The commands are only supported by "record btrace".
1713 record instruction-history prints the execution history at
1714 instruction granularity
1716 record function-call-history prints the execution history at
1717 function granularity
1719 * New native configurations
1721 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1722 FreeBSD/powerpc powerpc*-*-freebsd
1723 x86_64/Cygwin x86_64-*-cygwin*
1724 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1728 ARM AArch64 aarch64*-*-elf
1729 ARM AArch64 GNU/Linux aarch64*-*-linux
1730 Lynx 178 PowerPC powerpc-*-lynx*178
1731 x86_64/Cygwin x86_64-*-cygwin*
1732 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1734 * If the configured location of system.gdbinit file (as given by the
1735 --with-system-gdbinit option at configure time) is in the
1736 data-directory (as specified by --with-gdb-datadir at configure
1737 time) or in one of its subdirectories, then GDB will look for the
1738 system-wide init file in the directory specified by the
1739 --data-directory command-line option.
1741 * New command line options:
1743 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1744 other initialization files, unlike -nx which disables all of them.
1746 * Removed command line options
1748 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1751 * The 'ptype' and 'whatis' commands now accept an argument to control
1754 * 'info proc' now works on some core files.
1758 ** Vectors can be created with gdb.Type.vector.
1760 ** Python's atexit.register now works in GDB.
1762 ** Types can be pretty-printed via a Python API.
1764 ** Python 3 is now supported (in addition to Python 2.4 or later)
1766 ** New class gdb.Architecture exposes GDB's internal representation
1767 of architecture in the Python API.
1769 ** New method Frame.architecture returns the gdb.Architecture object
1770 corresponding to the frame's architecture.
1772 * New Python-based convenience functions:
1774 ** $_memeq(buf1, buf2, length)
1775 ** $_streq(str1, str2)
1777 ** $_regex(str, regex)
1779 * The 'cd' command now defaults to using '~' (the home directory) if not
1782 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1783 default for GCC since November 2000.
1785 * The command 'forward-search' can now be abbreviated as 'fo'.
1787 * The command 'info tracepoints' can now display 'installed on target'
1788 or 'not installed on target' for each non-pending location of tracepoint.
1790 * New configure options
1792 --enable-libmcheck/--disable-libmcheck
1793 By default, development versions are built with -lmcheck on hosts
1794 that support it, in order to help track memory corruption issues.
1795 Release versions, on the other hand, are built without -lmcheck
1796 by default. The --enable-libmcheck/--disable-libmcheck configure
1797 options allow the user to override that default.
1798 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1799 This configure option allows the user to build GDB with
1800 libbabeltrace using which GDB can read Common Trace Format data.
1802 * New commands (for set/show, see "New options" below)
1805 Catch signals. This is similar to "handle", but allows commands and
1806 conditions to be attached.
1809 List the BFDs known to GDB.
1811 python-interactive [command]
1813 Start a Python interactive prompt, or evaluate the optional command
1814 and print the result of expressions.
1817 "py" is a new alias for "python".
1819 enable type-printer [name]...
1820 disable type-printer [name]...
1821 Enable or disable type printers.
1825 ** For the Renesas Super-H architecture, the "regs" command has been removed
1826 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1831 set print type methods (on|off)
1832 show print type methods
1833 Control whether method declarations are displayed by "ptype".
1834 The default is to show them.
1836 set print type typedefs (on|off)
1837 show print type typedefs
1838 Control whether typedef definitions are displayed by "ptype".
1839 The default is to show them.
1841 set filename-display basename|relative|absolute
1842 show filename-display
1843 Control the way in which filenames is displayed.
1844 The default is "relative", which preserves previous behavior.
1846 set trace-buffer-size
1847 show trace-buffer-size
1848 Request target to change the size of trace buffer.
1850 set remote trace-buffer-size-packet auto|on|off
1851 show remote trace-buffer-size-packet
1852 Control the use of the remote protocol `QTBuffer:size' packet.
1856 Control display of debugging messages related to ARM AArch64.
1859 set debug coff-pe-read
1860 show debug coff-pe-read
1861 Control display of debugging messages related to reading of COFF/PE
1866 Control display of debugging messages related to Mach-O symbols
1869 set debug notification
1870 show debug notification
1871 Control display of debugging info for async remote notification.
1875 ** Command parameter changes are now notified using new async record
1876 "=cmd-param-changed".
1877 ** Trace frame changes caused by command "tfind" are now notified using
1878 new async record "=traceframe-changed".
1879 ** The creation, deletion and modification of trace state variables
1880 are now notified using new async records "=tsv-created",
1881 "=tsv-deleted" and "=tsv-modified".
1882 ** The start and stop of process record are now notified using new
1883 async record "=record-started" and "=record-stopped".
1884 ** Memory changes are now notified using new async record
1886 ** The data-disassemble command response will include a "fullname" field
1887 containing the absolute file name when source has been requested.
1888 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1889 command, to allow pattern filling of memory areas.
1890 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1891 library load/unload events.
1892 ** The response to breakpoint commands and breakpoint async records
1893 includes an "installed" field containing a boolean state about each
1894 non-pending tracepoint location is whether installed on target or not.
1895 ** Output of the "-trace-status" command includes a "trace-file" field
1896 containing the name of the trace file being examined. This field is
1897 optional, and only present when examining a trace file.
1898 ** The "fullname" field is now always present along with the "file" field,
1899 even if the file cannot be found by GDB.
1901 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1902 You must have the LZMA library available when configuring GDB for this
1903 feature to be enabled. For more information, see:
1904 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1906 * New remote packets
1909 Set the size of trace buffer. The remote stub reports support for this
1910 packet to gdb's qSupported query.
1913 Enable Branch Trace Store (BTS)-based branch tracing for the current
1914 thread. The remote stub reports support for this packet to gdb's
1918 Disable branch tracing for the current thread. The remote stub reports
1919 support for this packet to gdb's qSupported query.
1922 Read the traced branches for the current thread. The remote stub
1923 reports support for this packet to gdb's qSupported query.
1925 *** Changes in GDB 7.5
1927 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1928 for more x32 ABI info.
1930 * GDB now supports access to MIPS DSP registers on Linux targets.
1932 * GDB now supports debugging microMIPS binaries.
1934 * The "info os" command on GNU/Linux can now display information on
1935 several new classes of objects managed by the operating system:
1936 "info os procgroups" lists process groups
1937 "info os files" lists file descriptors
1938 "info os sockets" lists internet-domain sockets
1939 "info os shm" lists shared-memory regions
1940 "info os semaphores" lists semaphores
1941 "info os msg" lists message queues
1942 "info os modules" lists loaded kernel modules
1944 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1945 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1946 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1947 options and inspect the probe arguments using the new $_probe_arg family
1948 of convenience variables. You can obtain more information about SystemTap
1949 in <http://sourceware.org/systemtap/>.
1951 * GDB now supports reversible debugging on ARM, it allows you to
1952 debug basic ARM and THUMB instructions, and provides
1953 record/replay support.
1955 * The option "symbol-reloading" has been deleted as it is no longer used.
1959 ** GDB commands implemented in Python can now be put in command class
1962 ** The "maint set python print-stack on|off" is now deleted.
1964 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1965 apply "flag enum"-style pretty-printing to any enum.
1967 ** gdb.lookup_symbol can now work when there is no current frame.
1969 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1970 the source at which the symbol was defined.
1972 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1973 method 'value'. The former indicates whether the symbol needs a
1974 frame in order to compute its value, and the latter computes the
1977 ** A new method 'referenced_value' on gdb.Value objects which can
1978 dereference pointer as well as C++ reference values.
1980 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1981 which return the global and static blocks (as gdb.Block objects),
1982 of the underlying symbol table, respectively.
1984 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1985 object associated with a PC value.
1987 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1988 of the address range occupied by code for the current source line.
1990 * Go language support.
1991 GDB now supports debugging programs written in the Go programming
1994 * GDBserver now supports stdio connections.
1995 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1997 * The binary "gdbtui" can no longer be built or installed.
1998 Use "gdb -tui" instead.
2000 * GDB will now print "flag" enums specially. A flag enum is one where
2001 all the enumerator values have no bits in common when pairwise
2002 "and"ed. When printing a value whose type is a flag enum, GDB will
2003 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2004 (gdb) print (enum E) 3
2007 * The filename part of a linespec will now match trailing components
2008 of a source file name. For example, "break gcc/expr.c:1000" will
2009 now set a breakpoint in build/gcc/expr.c, but not
2010 build/libcpp/expr.c.
2012 * The "info proc" and "generate-core-file" commands will now also
2013 work on remote targets connected to GDBserver on Linux.
2015 * The command "info catch" has been removed. It has been disabled
2016 since December 2007.
2018 * The "catch exception" and "catch assert" commands now accept
2019 a condition at the end of the command, much like the "break"
2020 command does. For instance:
2022 (gdb) catch exception Constraint_Error if Barrier = True
2024 Previously, it was possible to add a condition to such catchpoints,
2025 but it had to be done as a second step, after the catchpoint had been
2026 created, using the "condition" command.
2028 * The "info static-tracepoint-marker" command will now also work on
2029 native Linux targets with in-process agent.
2031 * GDB can now set breakpoints on inlined functions.
2033 * The .gdb_index section has been updated to include symbols for
2034 inlined functions. GDB will ignore older .gdb_index sections by
2035 default, which could cause symbol files to be loaded more slowly
2036 until their .gdb_index sections can be recreated. The new command
2037 "set use-deprecated-index-sections on" will cause GDB to use any older
2038 .gdb_index sections it finds. This will restore performance, but the
2039 ability to set breakpoints on inlined functions will be lost in symbol
2040 files with older .gdb_index sections.
2042 The .gdb_index section has also been updated to record more information
2043 about each symbol. This speeds up the "info variables", "info functions"
2044 and "info types" commands when used with programs having the .gdb_index
2045 section, as well as speeding up debugging with shared libraries using
2046 the .gdb_index section.
2048 * Ada support for GDB/MI Variable Objects has been added.
2050 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2055 ** New command -info-os is the MI equivalent of "info os".
2057 ** Output logs ("set logging" and related) now include MI output.
2061 ** "set use-deprecated-index-sections on|off"
2062 "show use-deprecated-index-sections on|off"
2063 Controls the use of deprecated .gdb_index sections.
2065 ** "catch load" and "catch unload" can be used to stop when a shared
2066 library is loaded or unloaded, respectively.
2068 ** "enable count" can be used to auto-disable a breakpoint after
2071 ** "info vtbl" can be used to show the virtual method tables for
2072 C++ and Java objects.
2074 ** "explore" and its sub commands "explore value" and "explore type"
2075 can be used to recursively explore values and types of
2076 expressions. These commands are available only if GDB is
2077 configured with '--with-python'.
2079 ** "info auto-load" shows status of all kinds of auto-loaded files,
2080 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2081 sequences of commands files, "info auto-load python-scripts"
2082 shows status of auto-loading Python script files,
2083 "info auto-load local-gdbinit" shows status of loading init file
2084 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2085 status of inferior specific thread debugging shared library loading.
2087 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2088 and "show auto-load-scripts" commands have been deprecated, use their
2089 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2090 and "show auto-load python-scripts" counterparts instead.
2092 ** "dprintf location,format,args..." creates a dynamic printf, which
2093 is basically a breakpoint that does a printf and immediately
2094 resumes your program's execution, so it is like a printf that you
2095 can insert dynamically at runtime instead of at compiletime.
2097 ** "set print symbol"
2099 Controls whether GDB attempts to display the symbol, if any,
2100 corresponding to addresses it prints. This defaults to "on", but
2101 you can set it to "off" to restore GDB's previous behavior.
2103 * Deprecated commands
2105 ** For the Renesas Super-H architecture, the "regs" command has been
2106 deprecated, and "info all-registers" should be used instead.
2110 Renesas RL78 rl78-*-elf
2111 HP OpenVMS ia64 ia64-hp-openvms*
2113 * GDBserver supports evaluation of breakpoint conditions. When
2114 support is advertised by GDBserver, GDB may be told to send the
2115 breakpoint conditions in bytecode form to GDBserver. GDBserver
2116 will only report the breakpoint trigger to GDB when its condition
2121 set mips compression
2122 show mips compression
2123 Select the compressed ISA encoding used in functions that have no symbol
2124 information available. The encoding can be set to either of:
2127 and is updated automatically from ELF file flags if available.
2129 set breakpoint condition-evaluation
2130 show breakpoint condition-evaluation
2131 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2132 GDBserver ("target"). Default option "auto" chooses the most efficient
2134 This option can improve debugger efficiency depending on the speed of the
2138 Disable auto-loading globally.
2141 Show auto-loading setting of all kinds of auto-loaded files.
2143 set auto-load gdb-scripts on|off
2144 show auto-load gdb-scripts
2145 Control auto-loading of GDB canned sequences of commands files.
2147 set auto-load python-scripts on|off
2148 show auto-load python-scripts
2149 Control auto-loading of Python script files.
2151 set auto-load local-gdbinit on|off
2152 show auto-load local-gdbinit
2153 Control loading of init file (.gdbinit) from current directory.
2155 set auto-load libthread-db on|off
2156 show auto-load libthread-db
2157 Control auto-loading of inferior specific thread debugging shared library.
2159 set auto-load scripts-directory <dir1>[:<dir2>...]
2160 show auto-load scripts-directory
2161 Set a list of directories from which to load auto-loaded scripts.
2162 Automatically loaded Python scripts and GDB scripts are located in one
2163 of the directories listed by this option.
2164 The delimiter (':' above) may differ according to the host platform.
2166 set auto-load safe-path <dir1>[:<dir2>...]
2167 show auto-load safe-path
2168 Set a list of directories from which it is safe to auto-load files.
2169 The delimiter (':' above) may differ according to the host platform.
2171 set debug auto-load on|off
2172 show debug auto-load
2173 Control display of debugging info for auto-loading the files above.
2175 set dprintf-style gdb|call|agent
2177 Control the way in which a dynamic printf is performed; "gdb"
2178 requests a GDB printf command, while "call" causes dprintf to call a
2179 function in the inferior. "agent" requests that the target agent
2180 (such as GDBserver) do the printing.
2182 set dprintf-function <expr>
2183 show dprintf-function
2184 set dprintf-channel <expr>
2185 show dprintf-channel
2186 Set the function and optional first argument to the call when using
2187 the "call" style of dynamic printf.
2189 set disconnected-dprintf on|off
2190 show disconnected-dprintf
2191 Control whether agent-style dynamic printfs continue to be in effect
2192 after GDB disconnects.
2194 * New configure options
2196 --with-auto-load-dir
2197 Configure default value for the 'set auto-load scripts-directory'
2198 setting above. It defaults to '$debugdir:$datadir/auto-load',
2199 $debugdir representing global debugging info directories (available
2200 via 'show debug-file-directory') and $datadir representing GDB's data
2201 directory (available via 'show data-directory').
2203 --with-auto-load-safe-path
2204 Configure default value for the 'set auto-load safe-path' setting
2205 above. It defaults to the --with-auto-load-dir setting.
2207 --without-auto-load-safe-path
2208 Set 'set auto-load safe-path' to '/', effectively disabling this
2211 * New remote packets
2213 z0/z1 conditional breakpoints extension
2215 The z0/z1 breakpoint insertion packets have been extended to carry
2216 a list of conditional expressions over to the remote stub depending on the
2217 condition evaluation mode. The use of this extension can be controlled
2218 via the "set remote conditional-breakpoints-packet" command.
2222 Specify the signals which the remote stub may pass to the debugged
2223 program without GDB involvement.
2225 * New command line options
2227 --init-command=FILE, -ix Like --command, -x but execute it
2228 before loading inferior.
2229 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2230 execute it before loading inferior.
2232 *** Changes in GDB 7.4
2234 * GDB now handles ambiguous linespecs more consistently; the existing
2235 FILE:LINE support has been expanded to other types of linespecs. A
2236 breakpoint will now be set on all matching locations in all
2237 inferiors, and locations will be added or removed according to
2240 * GDB now allows you to skip uninteresting functions and files when
2241 stepping with the "skip function" and "skip file" commands.
2243 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2244 and "show remote hardware-watchpoint-length-limit". These allows to
2245 set or show the maximum length limit (in bytes) of a remote
2246 target hardware watchpoint.
2248 This allows e.g. to use "unlimited" hardware watchpoints with the
2249 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2250 watchpoints are slower than real hardware watchpoints but are
2251 significantly faster than gdb software watchpoints.
2255 ** The register_pretty_printer function in module gdb.printing now takes
2256 an optional `replace' argument. If True, the new printer replaces any
2259 ** The "maint set python print-stack on|off" command has been
2260 deprecated and will be deleted in GDB 7.5.
2261 A new command: "set python print-stack none|full|message" has
2262 replaced it. Additionally, the default for "print-stack" is
2263 now "message", which just prints the error message without
2266 ** A prompt substitution hook (prompt_hook) is now available to the
2269 ** A new Python module, gdb.prompt has been added to the GDB Python
2270 modules library. This module provides functionality for
2271 escape sequences in prompts (used by set/show
2272 extended-prompt). These escape sequences are replaced by their
2273 corresponding value.
2275 ** Python commands and convenience-functions located in
2276 'data-directory'/python/gdb/command and
2277 'data-directory'/python/gdb/function are now automatically loaded
2280 ** Blocks now provide four new attributes. global_block and
2281 static_block will return the global and static blocks
2282 respectively. is_static and is_global are boolean attributes
2283 that indicate if the block is one of those two types.
2285 ** Symbols now provide the "type" attribute, the type of the symbol.
2287 ** The "gdb.breakpoint" function has been deprecated in favor of
2290 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2291 of a function. This class is based on the "finish" command
2292 available in the CLI.
2294 ** Type objects for struct and union types now allow access to
2295 the fields using standard Python dictionary (mapping) methods.
2296 For example, "some_type['myfield']" now works, as does
2297 "some_type.items()".
2299 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2302 ** A new function, "deep_items" has been added to the gdb.types
2303 module in the GDB Python modules library. This function returns
2304 an iterator over the fields of a struct or union type. Unlike
2305 the standard Python "iteritems" method, it will recursively traverse
2306 any anonymous fields.
2310 ** "*stopped" events can report several new "reason"s, such as
2313 ** Breakpoint changes are now notified using new async records, like
2314 "=breakpoint-modified".
2316 ** New command -ada-task-info.
2318 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2319 $sdir specifies the default system locations of shared libraries.
2320 $pdir specifies the directory where the libpthread used by the application
2323 GDB no longer looks in $sdir and $pdir after it has searched the directories
2324 mentioned in libthread-db-search-path. If you want to search those
2325 directories, they must be specified in libthread-db-search-path.
2326 The default value of libthread-db-search-path on GNU/Linux and Solaris
2327 systems is now "$sdir:$pdir".
2329 $pdir is not supported by gdbserver, it is currently ignored.
2330 $sdir is supported by gdbserver.
2332 * New configure option --with-iconv-bin.
2333 When using the internationalization support like the one in the GNU C
2334 library, GDB will invoke the "iconv" program to get a list of supported
2335 character sets. If this program lives in a non-standard location, one can
2336 use this option to specify where to find it.
2338 * When natively debugging programs on PowerPC BookE processors running
2339 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2340 watchpoints, which specify a mask in addition to an address to watch.
2341 The mask specifies that some bits of an address (the bits which are
2342 reset in the mask) should be ignored when matching the address accessed
2343 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2344 section in the user manual for more details.
2346 * The new option --once causes GDBserver to stop listening for connections once
2347 the first connection is made. The listening port used by GDBserver will
2348 become available after that.
2350 * New commands "info macros" and "alias" have been added.
2352 * New function parameters suffix @entry specifies value of function parameter
2353 at the time the function got called. Entry values are available only since
2359 "!" is now an alias of the "shell" command.
2360 Note that no space is needed between "!" and SHELL COMMAND.
2364 watch EXPRESSION mask MASK_VALUE
2365 The watch command now supports the mask argument which allows creation
2366 of masked watchpoints, if the current architecture supports this feature.
2368 info auto-load-scripts [REGEXP]
2369 This command was formerly named "maintenance print section-scripts".
2370 It is now generally useful and is no longer a maintenance-only command.
2372 info macro [-all] [--] MACRO
2373 The info macro command has new options `-all' and `--'. The first for
2374 printing all definitions of a macro. The second for explicitly specifying
2375 the end of arguments and the beginning of the macro name in case the macro
2376 name starts with a hyphen.
2378 collect[/s] EXPRESSIONS
2379 The tracepoint collect command now takes an optional modifier "/s"
2380 that directs it to dereference pointer-to-character types and
2381 collect the bytes of memory up to a zero byte. The behavior is
2382 similar to what you see when you use the regular print command on a
2383 string. An optional integer following the "/s" sets a bound on the
2384 number of bytes that will be collected.
2387 The trace start command now interprets any supplied arguments as a
2388 note to be recorded with the trace run, with an effect similar to
2389 setting the variable trace-notes.
2392 The trace stop command now interprets any arguments as a note to be
2393 mentioned along with the tstatus report that the trace was stopped
2394 with a command. The effect is similar to setting the variable
2397 * Tracepoints can now be enabled and disabled at any time after a trace
2398 experiment has been started using the standard "enable" and "disable"
2399 commands. It is now possible to start a trace experiment with no enabled
2400 tracepoints; GDB will display a warning, but will allow the experiment to
2401 begin, assuming that tracepoints will be enabled as needed while the trace
2404 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2405 locations with 4-byte instructions, when they were previously
2406 limited to locations with instructions of 5 bytes or longer.
2410 set debug dwarf2-read
2411 show debug dwarf2-read
2412 Turns on or off display of debugging messages related to reading
2413 DWARF debug info. The default is off.
2415 set debug symtab-create
2416 show debug symtab-create
2417 Turns on or off display of debugging messages related to symbol table
2418 creation. The default is off.
2421 show extended-prompt
2422 Set the GDB prompt, and allow escape sequences to be inserted to
2423 display miscellaneous information (see 'help set extended-prompt'
2424 for the list of sequences). This prompt (and any information
2425 accessed through the escape sequences) is updated every time the
2426 prompt is displayed.
2428 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2429 show print entry-values
2430 Set printing of frame argument values at function entry. In some cases
2431 GDB can determine the value of function argument which was passed by the
2432 function caller, even if the value was modified inside the called function.
2434 set debug entry-values
2435 show debug entry-values
2436 Control display of debugging info for determining frame argument values at
2437 function entry and virtual tail call frames.
2439 set basenames-may-differ
2440 show basenames-may-differ
2441 Set whether a source file may have multiple base names.
2442 (A "base name" is the name of a file with the directory part removed.
2443 Example: The base name of "/home/user/hello.c" is "hello.c".)
2444 If set, GDB will canonicalize file names (e.g., expand symlinks)
2445 before comparing them. Canonicalization is an expensive operation,
2446 but it allows the same file be known by more than one base name.
2447 If not set (the default), all source files are assumed to have just
2448 one base name, and gdb will do file name comparisons more efficiently.
2454 Set a user name and notes for the current and any future trace runs.
2455 This is useful for long-running and/or disconnected traces, to
2456 inform others (or yourself) as to who is running the trace, supply
2457 contact information, or otherwise explain what is going on.
2459 set trace-stop-notes
2460 show trace-stop-notes
2461 Set a note attached to the trace run, that is displayed when the
2462 trace has been stopped by a tstop command. This is useful for
2463 instance as an explanation, if you are stopping a trace run that was
2464 started by someone else.
2466 * New remote packets
2470 Dynamically enable a tracepoint in a started trace experiment.
2474 Dynamically disable a tracepoint in a started trace experiment.
2478 Set the user and notes of the trace run.
2482 Query the current status of a tracepoint.
2486 Query the minimum length of instruction at which a fast tracepoint may
2489 * Dcache size (number of lines) and line-size are now runtime-configurable
2490 via "set dcache line" and "set dcache line-size" commands.
2494 Texas Instruments TMS320C6x tic6x-*-*
2498 Renesas RL78 rl78-*-elf
2500 *** Changes in GDB 7.3.1
2502 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2504 *** Changes in GDB 7.3
2506 * GDB has a new command: "thread find [REGEXP]".
2507 It finds the thread id whose name, target id, or thread extra info
2508 matches the given regular expression.
2510 * The "catch syscall" command now works on mips*-linux* targets.
2512 * The -data-disassemble MI command now supports modes 2 and 3 for
2513 dumping the instruction opcodes.
2515 * New command line options
2517 -data-directory DIR Specify DIR as the "data-directory".
2518 This is mostly for testing purposes.
2520 * The "maint set python auto-load on|off" command has been renamed to
2521 "set auto-load-scripts on|off".
2523 * GDB has a new command: "set directories".
2524 It is like the "dir" command except that it replaces the
2525 source path list instead of augmenting it.
2527 * GDB now understands thread names.
2529 On GNU/Linux, "info threads" will display the thread name as set by
2530 prctl or pthread_setname_np.
2532 There is also a new command, "thread name", which can be used to
2533 assign a name internally for GDB to display.
2536 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2537 has been integrated into GDB.
2541 ** The function gdb.Write now accepts an optional keyword 'stream'.
2542 This keyword, when provided, will direct the output to either
2543 stdout, stderr, or GDB's logging output.
2545 ** Parameters can now be be sub-classed in Python, and in particular
2546 you may implement the get_set_doc and get_show_doc functions.
2547 This improves how Parameter set/show documentation is processed
2548 and allows for more dynamic content.
2550 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2551 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2552 have an is_valid method.
2554 ** Breakpoints can now be sub-classed in Python, and in particular
2555 you may implement a 'stop' function that is executed each time
2556 the inferior reaches that breakpoint.
2558 ** New function gdb.lookup_global_symbol looks up a global symbol.
2560 ** GDB values in Python are now callable if the value represents a
2561 function. For example, if 'some_value' represents a function that
2562 takes two integer parameters and returns a value, you can call
2563 that function like so:
2565 result = some_value (10,20)
2567 ** Module gdb.types has been added.
2568 It contains a collection of utilities for working with gdb.Types objects:
2569 get_basic_type, has_field, make_enum_dict.
2571 ** Module gdb.printing has been added.
2572 It contains utilities for writing and registering pretty-printers.
2573 New classes: PrettyPrinter, SubPrettyPrinter,
2574 RegexpCollectionPrettyPrinter.
2575 New function: register_pretty_printer.
2577 ** New commands "info pretty-printers", "enable pretty-printer" and
2578 "disable pretty-printer" have been added.
2580 ** gdb.parameter("directories") is now available.
2582 ** New function gdb.newest_frame returns the newest frame in the
2585 ** The gdb.InferiorThread class has a new "name" attribute. This
2586 holds the thread's name.
2588 ** Python Support for Inferior events.
2589 Python scripts can add observers to be notified of events
2590 occurring in the process being debugged.
2591 The following events are currently supported:
2592 - gdb.events.cont Continue event.
2593 - gdb.events.exited Inferior exited event.
2594 - gdb.events.stop Signal received, and Breakpoint hit events.
2598 ** GDB now puts template parameters in scope when debugging in an
2599 instantiation. For example, if you have:
2601 template<int X> int func (void) { return X; }
2603 then if you step into func<5>, "print X" will show "5". This
2604 feature requires proper debuginfo support from the compiler; it
2605 was added to GCC 4.5.
2607 ** The motion commands "next", "finish", "until", and "advance" now
2608 work better when exceptions are thrown. In particular, GDB will
2609 no longer lose control of the inferior; instead, the GDB will
2610 stop the inferior at the point at which the exception is caught.
2611 This functionality requires a change in the exception handling
2612 code that was introduced in GCC 4.5.
2614 * GDB now follows GCC's rules on accessing volatile objects when
2615 reading or writing target state during expression evaluation.
2616 One notable difference to prior behavior is that "print x = 0"
2617 no longer generates a read of x; the value of the assignment is
2618 now always taken directly from the value being assigned.
2620 * GDB now has some support for using labels in the program's source in
2621 linespecs. For instance, you can use "advance label" to continue
2622 execution to a label.
2624 * GDB now has support for reading and writing a new .gdb_index
2625 section. This section holds a fast index of DWARF debugging
2626 information and can be used to greatly speed up GDB startup and
2627 operation. See the documentation for `save gdb-index' for details.
2629 * The "watch" command now accepts an optional "-location" argument.
2630 When used, this causes GDB to watch the memory referred to by the
2631 expression. Such a watchpoint is never deleted due to it going out
2634 * GDB now supports thread debugging of core dumps on GNU/Linux.
2636 GDB now activates thread debugging using the libthread_db library
2637 when debugging GNU/Linux core dumps, similarly to when debugging
2638 live processes. As a result, when debugging a core dump file, GDB
2639 is now able to display pthread_t ids of threads. For example, "info
2640 threads" shows the same output as when debugging the process when it
2641 was live. In earlier releases, you'd see something like this:
2644 * 1 LWP 6780 main () at main.c:10
2646 While now you see this:
2649 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2651 It is also now possible to inspect TLS variables when debugging core
2654 When debugging a core dump generated on a machine other than the one
2655 used to run GDB, you may need to point GDB at the correct
2656 libthread_db library with the "set libthread-db-search-path"
2657 command. See the user manual for more details on this command.
2659 * When natively debugging programs on PowerPC BookE processors running
2660 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2661 which stop execution of the inferior whenever it executes an instruction
2662 at any address within the specified range. See the "PowerPC Embedded"
2663 section in the user manual for more details.
2665 * New features in the GDB remote stub, GDBserver
2667 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2668 and i686 LynxOS (version 5.x).
2670 ** GDBserver is now supported on Blackfin Linux.
2672 * New native configurations
2674 ia64 HP-UX ia64-*-hpux*
2678 Analog Devices, Inc. Blackfin Processor bfin-*
2680 * Ada task switching is now supported on sparc-elf targets when
2681 debugging a program using the Ravenscar Profile. For more information,
2682 see the "Tasking Support when using the Ravenscar Profile" section
2683 in the GDB user manual.
2685 * Guile support was removed.
2687 * New features in the GNU simulator
2689 ** The --map-info flag lists all known core mappings.
2691 ** CFI flashes may be simulated via the "cfi" device.
2693 *** Changes in GDB 7.2
2695 * Shared library support for remote targets by default
2697 When GDB is configured for a generic, non-OS specific target, like
2698 for example, --target=arm-eabi or one of the many *-*-elf targets,
2699 GDB now queries remote stubs for loaded shared libraries using the
2700 `qXfer:libraries:read' packet. Previously, shared library support
2701 was always disabled for such configurations.
2705 ** Argument Dependent Lookup (ADL)
2707 In C++ ADL lookup directs function search to the namespaces of its
2708 arguments even if the namespace has not been imported.
2718 Here the compiler will search for `foo' in the namespace of 'b'
2719 and find A::foo. GDB now supports this. This construct is commonly
2720 used in the Standard Template Library for operators.
2722 ** Improved User Defined Operator Support
2724 In addition to member operators, GDB now supports lookup of operators
2725 defined in a namespace and imported with a `using' directive, operators
2726 defined in the global scope, operators imported implicitly from an
2727 anonymous namespace, and the ADL operators mentioned in the previous
2729 GDB now also supports proper overload resolution for all the previously
2730 mentioned flavors of operators.
2732 ** static const class members
2734 Printing of static const class members that are initialized in the
2735 class definition has been fixed.
2737 * Windows Thread Information Block access.
2739 On Windows targets, GDB now supports displaying the Windows Thread
2740 Information Block (TIB) structure. This structure is visible either
2741 by using the new command `info w32 thread-information-block' or, by
2742 dereferencing the new convenience variable named `$_tlb', a
2743 thread-specific pointer to the TIB. This feature is also supported
2744 when remote debugging using GDBserver.
2746 * Static tracepoints
2748 Static tracepoints are calls in the user program into a tracing
2749 library. One such library is a port of the LTTng kernel tracer to
2750 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2751 When debugging with GDBserver, GDB now supports combining the GDB
2752 tracepoint machinery with such libraries. For example: the user can
2753 use GDB to probe a static tracepoint marker (a call from the user
2754 program into the tracing library) with the new "strace" command (see
2755 "New commands" below). This creates a "static tracepoint" in the
2756 breakpoint list, that can be manipulated with the same feature set
2757 as fast and regular tracepoints. E.g., collect registers, local and
2758 global variables, collect trace state variables, and define
2759 tracepoint conditions. In addition, the user can collect extra
2760 static tracepoint marker specific data, by collecting the new
2761 $_sdata internal variable. When analyzing the trace buffer, you can
2762 inspect $_sdata like any other variable available to GDB. For more
2763 information, see the "Tracepoints" chapter in GDB user manual. New
2764 remote packets have been defined to support static tracepoints, see
2765 the "New remote packets" section below.
2767 * Better reconstruction of tracepoints after disconnected tracing
2769 GDB will attempt to download the original source form of tracepoint
2770 definitions when starting a trace run, and then will upload these
2771 upon reconnection to the target, resulting in a more accurate
2772 reconstruction of the tracepoints that are in use on the target.
2776 You can now exercise direct control over the ways that GDB can
2777 affect your program. For instance, you can disallow the setting of
2778 breakpoints, so that the program can run continuously (assuming
2779 non-stop mode). In addition, the "observer" variable is available
2780 to switch all of the different controls; in observer mode, GDB
2781 cannot affect the target's behavior at all, which is useful for
2782 tasks like diagnosing live systems in the field.
2784 * The new convenience variable $_thread holds the number of the
2787 * New remote packets
2791 Return the address of the Windows Thread Information Block of a given thread.
2795 In response to several of the tracepoint packets, the target may now
2796 also respond with a number of intermediate `qRelocInsn' request
2797 packets before the final result packet, to have GDB handle
2798 relocating an instruction to execute at a different address. This
2799 is particularly useful for stubs that support fast tracepoints. GDB
2800 reports support for this feature in the qSupported packet.
2804 List static tracepoint markers in the target program.
2808 List static tracepoint markers at a given address in the target
2811 qXfer:statictrace:read
2813 Read the static trace data collected (by a `collect $_sdata'
2814 tracepoint action). The remote stub reports support for this packet
2815 to gdb's qSupported query.
2819 Send the current settings of GDB's permission flags.
2823 Send part of the source (textual) form of a tracepoint definition,
2824 which includes location, conditional, and action list.
2826 * The source command now accepts a -s option to force searching for the
2827 script in the source search path even if the script name specifies
2830 * New features in the GDB remote stub, GDBserver
2832 - GDBserver now support tracepoints (including fast tracepoints, and
2833 static tracepoints). The feature is currently supported by the
2834 i386-linux and amd64-linux builds. See the "Tracepoints support
2835 in gdbserver" section in the manual for more information.
2837 GDBserver JIT compiles the tracepoint's conditional agent
2838 expression bytecode into native code whenever possible for low
2839 overhead dynamic tracepoints conditionals. For such tracepoints,
2840 an expression that examines program state is evaluated when the
2841 tracepoint is reached, in order to determine whether to capture
2842 trace data. If the condition is simple and false, processing the
2843 tracepoint finishes very quickly and no data is gathered.
2845 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2846 for static tracepoints support.
2848 - GDBserver now supports x86_64 Windows 64-bit debugging.
2850 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2851 it understands register description.
2853 * The --batch flag now disables pagination and queries.
2855 * X86 general purpose registers
2857 GDB now supports reading/writing byte, word and double-word x86
2858 general purpose registers directly. This means you can use, say,
2859 $ah or $ax to refer, respectively, to the byte register AH and
2860 16-bit word register AX that are actually portions of the 32-bit
2861 register EAX or 64-bit register RAX.
2863 * The `commands' command now accepts a range of breakpoints to modify.
2864 A plain `commands' following a command that creates multiple
2865 breakpoints affects all the breakpoints set by that command. This
2866 applies to breakpoints set by `rbreak', and also applies when a
2867 single `break' command creates multiple breakpoints (e.g.,
2868 breakpoints on overloaded c++ functions).
2870 * The `rbreak' command now accepts a filename specification as part of
2871 its argument, limiting the functions selected by the regex to those
2872 in the specified file.
2874 * Support for remote debugging Windows and SymbianOS shared libraries
2875 from Unix hosts has been improved. Non Windows GDB builds now can
2876 understand target reported file names that follow MS-DOS based file
2877 system semantics, such as file names that include drive letters and
2878 use the backslash character as directory separator. This makes it
2879 possible to transparently use the "set sysroot" and "set
2880 solib-search-path" on Unix hosts to point as host copies of the
2881 target's shared libraries. See the new command "set
2882 target-file-system-kind" described below, and the "Commands to
2883 specify files" section in the user manual for more information.
2887 eval template, expressions...
2888 Convert the values of one or more expressions under the control
2889 of the string template to a command line, and call it.
2891 set target-file-system-kind unix|dos-based|auto
2892 show target-file-system-kind
2893 Set or show the assumed file system kind for target reported file
2896 save breakpoints <filename>
2897 Save all current breakpoint definitions to a file suitable for use
2898 in a later debugging session. To read the saved breakpoint
2899 definitions, use the `source' command.
2901 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2904 info static-tracepoint-markers
2905 Display information about static tracepoint markers in the target.
2907 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2908 Define a static tracepoint by probing a marker at the given
2909 function, line, address, or marker ID.
2913 Enable and disable observer mode.
2915 set may-write-registers on|off
2916 set may-write-memory on|off
2917 set may-insert-breakpoints on|off
2918 set may-insert-tracepoints on|off
2919 set may-insert-fast-tracepoints on|off
2920 set may-interrupt on|off
2921 Set individual permissions for GDB effects on the target. Note that
2922 some of these settings can have undesirable or surprising
2923 consequences, particularly when changed in the middle of a session.
2924 For instance, disabling the writing of memory can prevent
2925 breakpoints from being inserted, cause single-stepping to fail, or
2926 even crash your program, if you disable after breakpoints have been
2927 inserted. However, GDB should not crash.
2929 set record memory-query on|off
2930 show record memory-query
2931 Control whether to stop the inferior if memory changes caused
2932 by an instruction cannot be recorded.
2937 The disassemble command now supports "start,+length" form of two arguments.
2941 ** GDB now provides a new directory location, called the python directory,
2942 where Python scripts written for GDB can be installed. The location
2943 of that directory is <data-directory>/python, where <data-directory>
2944 is the GDB data directory. For more details, see section `Scripting
2945 GDB using Python' in the manual.
2947 ** The GDB Python API now has access to breakpoints, symbols, symbol
2948 tables, program spaces, inferiors, threads and frame's code blocks.
2949 Additionally, GDB Parameters can now be created from the API, and
2950 manipulated via set/show in the CLI.
2952 ** New functions gdb.target_charset, gdb.target_wide_charset,
2953 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2955 ** New exception gdb.GdbError.
2957 ** Pretty-printers are now also looked up in the current program space.
2959 ** Pretty-printers can now be individually enabled and disabled.
2961 ** GDB now looks for names of Python scripts to auto-load in a
2962 special section named `.debug_gdb_scripts', in addition to looking
2963 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2965 * Tracepoint actions were unified with breakpoint commands. In particular,
2966 there are no longer differences in "info break" output for breakpoints and
2967 tracepoints and the "commands" command can be used for both tracepoints and
2968 regular breakpoints.
2972 ARM Symbian arm*-*-symbianelf*
2974 * D language support.
2975 GDB now supports debugging programs written in the D programming
2978 * GDB now supports the extended ptrace interface for PowerPC which is
2979 available since Linux kernel version 2.6.34. This automatically enables
2980 any hardware breakpoints and additional hardware watchpoints available in
2981 the processor. The old ptrace interface exposes just one hardware
2982 watchpoint and no hardware breakpoints.
2984 * GDB is now able to use the Data Value Compare (DVC) register available on
2985 embedded PowerPC processors to implement in hardware simple watchpoint
2986 conditions of the form:
2988 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2990 This works in native GDB running on Linux kernels with the extended ptrace
2991 interface mentioned above.
2993 *** Changes in GDB 7.1
2997 ** Namespace Support
2999 GDB now supports importing of namespaces in C++. This enables the
3000 user to inspect variables from imported namespaces. Support for
3001 namepace aliasing has also been added. So, if a namespace is
3002 aliased in the current scope (e.g. namepace C=A; ) the user can
3003 print variables using the alias (e.g. (gdb) print C::x).
3007 All known bugs relating to the printing of virtual base class were
3008 fixed. It is now possible to call overloaded static methods using a
3013 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3014 and reinterpret_cast<> are now handled by the C++ expression parser.
3018 Xilinx MicroBlaze microblaze-*-*
3023 Xilinx MicroBlaze microblaze
3026 * Multi-program debugging.
3028 GDB now has support for multi-program (a.k.a. multi-executable or
3029 multi-exec) debugging. This allows for debugging multiple inferiors
3030 simultaneously each running a different program under the same GDB
3031 session. See "Debugging Multiple Inferiors and Programs" in the
3032 manual for more information. This implied some user visible changes
3033 in the multi-inferior support. For example, "info inferiors" now
3034 lists inferiors that are not running yet or that have exited
3035 already. See also "New commands" and "New options" below.
3037 * New tracing features
3039 GDB's tracepoint facility now includes several new features:
3041 ** Trace state variables
3043 GDB tracepoints now include support for trace state variables, which
3044 are variables managed by the target agent during a tracing
3045 experiment. They are useful for tracepoints that trigger each
3046 other, so for instance one tracepoint can count hits in a variable,
3047 and then a second tracepoint has a condition that is true when the
3048 count reaches a particular value. Trace state variables share the
3049 $-syntax of GDB convenience variables, and can appear in both
3050 tracepoint actions and condition expressions. Use the "tvariable"
3051 command to create, and "info tvariables" to view; see "Trace State
3052 Variables" in the manual for more detail.
3056 GDB now includes an option for defining fast tracepoints, which
3057 targets may implement more efficiently, such as by installing a jump
3058 into the target agent rather than a trap instruction. The resulting
3059 speedup can be by two orders of magnitude or more, although the
3060 tradeoff is that some program locations on some target architectures
3061 might not allow fast tracepoint installation, for instance if the
3062 instruction to be replaced is shorter than the jump. To request a
3063 fast tracepoint, use the "ftrace" command, with syntax identical to
3064 the regular trace command.
3066 ** Disconnected tracing
3068 It is now possible to detach GDB from the target while it is running
3069 a trace experiment, then reconnect later to see how the experiment
3070 is going. In addition, a new variable disconnected-tracing lets you
3071 tell the target agent whether to continue running a trace if the
3072 connection is lost unexpectedly.
3076 GDB now has the ability to save the trace buffer into a file, and
3077 then use that file as a target, similarly to you can do with
3078 corefiles. You can select trace frames, print data that was
3079 collected in them, and use tstatus to display the state of the
3080 tracing run at the moment that it was saved. To create a trace
3081 file, use "tsave <filename>", and to use it, do "target tfile
3084 ** Circular trace buffer
3086 You can ask the target agent to handle the trace buffer as a
3087 circular buffer, discarding the oldest trace frames to make room for
3088 newer ones, by setting circular-trace-buffer to on. This feature may
3089 not be available for all target agents.
3094 The disassemble command, when invoked with two arguments, now requires
3095 the arguments to be comma-separated.
3098 The info variables command now displays variable definitions. Files
3099 which only declare a variable are not shown.
3102 The source command is now capable of sourcing Python scripts.
3103 This feature is dependent on the debugger being build with Python
3106 Related to this enhancement is also the introduction of a new command
3107 "set script-extension" (see below).
3109 * New commands (for set/show, see "New options" below)
3111 record save [<FILENAME>]
3112 Save a file (in core file format) containing the process record
3113 execution log for replay debugging at a later time.
3115 record restore <FILENAME>
3116 Restore the process record execution log that was saved at an
3117 earlier time, for replay debugging.
3119 add-inferior [-copies <N>] [-exec <FILENAME>]
3122 clone-inferior [-copies <N>] [ID]
3123 Make a new inferior ready to execute the same program another
3124 inferior has loaded.
3129 maint info program-spaces
3130 List the program spaces loaded into GDB.
3132 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3133 show remote interrupt-sequence
3134 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3135 as the sequence to the remote target in order to interrupt the execution.
3136 Ctrl-C is a default. Some system prefers BREAK which is high level of
3137 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3138 Magic SysRq g. It is BREAK signal and character 'g'.
3140 set remote interrupt-on-connect [on | off]
3141 show remote interrupt-on-connect
3142 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3143 remote target when gdb connects to it. This is needed when you debug
3146 set remotebreak [on | off]
3148 Deprecated. Use "set/show remote interrupt-sequence" instead.
3150 tvariable $NAME [ = EXP ]
3151 Create or modify a trace state variable.
3154 List trace state variables and their values.
3156 delete tvariable $NAME ...
3157 Delete one or more trace state variables.
3160 Evaluate the given expressions without collecting anything into the
3161 trace buffer. (Valid in tracepoint actions only.)
3163 ftrace FN / FILE:LINE / *ADDR
3164 Define a fast tracepoint at the given function, line, or address.
3166 * New expression syntax
3168 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3169 GDB now parses 0b101010 identically with 42.
3173 set follow-exec-mode new|same
3174 show follow-exec-mode
3175 Control whether GDB reuses the same inferior across an exec call or
3176 creates a new one. This is useful to be able to restart the old
3177 executable after the inferior having done an exec call.
3179 set default-collect EXPR, ...
3180 show default-collect
3181 Define a list of expressions to be collected at each tracepoint.
3182 This is a useful way to ensure essential items are not overlooked,
3183 such as registers or a critical global variable.
3185 set disconnected-tracing
3186 show disconnected-tracing
3187 If set to 1, the target is instructed to continue tracing if it
3188 loses its connection to GDB. If 0, the target is to stop tracing
3191 set circular-trace-buffer
3192 show circular-trace-buffer
3193 If set to on, the target is instructed to use a circular trace buffer
3194 and discard the oldest trace frames instead of stopping the trace due
3195 to a full trace buffer. If set to off, the trace stops when the buffer
3196 fills up. Some targets may not support this.
3198 set script-extension off|soft|strict
3199 show script-extension
3200 If set to "off", the debugger does not perform any script language
3201 recognition, and all sourced files are assumed to be GDB scripts.
3202 If set to "soft" (the default), files are sourced according to
3203 filename extension, falling back to GDB scripts if the first
3205 If set to "strict", files are sourced according to filename extension.
3207 set ada trust-PAD-over-XVS on|off
3208 show ada trust-PAD-over-XVS
3209 If off, activate a workaround against a bug in the debugging information
3210 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3211 the GCC sources for more information about the GNAT encoding and
3212 PAD types in particular). It is always safe to set this option to
3213 off, but this introduces a slight performance penalty. The default
3216 * Python API Improvements
3218 ** GDB provides the new class gdb.LazyString. This is useful in
3219 some pretty-printing cases. The new method gdb.Value.lazy_string
3220 provides a simple way to create objects of this type.
3222 ** The fields returned by gdb.Type.fields now have an
3223 `is_base_class' attribute.
3225 ** The new method gdb.Type.range returns the range of an array type.
3227 ** The new method gdb.parse_and_eval can be used to parse and
3228 evaluate an expression.
3230 * New remote packets
3233 Define a trace state variable.
3236 Get the current value of a trace state variable.
3239 Set desired tracing behavior upon disconnection.
3242 Set the trace buffer to be linear or circular.
3245 Get data about the tracepoints currently in use.
3249 Process record now works correctly with hardware watchpoints.
3251 Multiple bug fixes have been made to the mips-irix port, making it
3252 much more reliable. In particular:
3253 - Debugging threaded applications is now possible again. Previously,
3254 GDB would hang while starting the program, or while waiting for
3255 the program to stop at a breakpoint.
3256 - Attaching to a running process no longer hangs.
3257 - An error occurring while loading a core file has been fixed.
3258 - Changing the value of the PC register now works again. This fixes
3259 problems observed when using the "jump" command, or when calling
3260 a function from GDB, or even when assigning a new value to $pc.
3261 - With the "finish" and "return" commands, the return value for functions
3262 returning a small array is now correctly printed.
3263 - It is now possible to break on shared library code which gets executed
3264 during a shared library init phase (code executed while executing
3265 their .init section). Previously, the breakpoint would have no effect.
3266 - GDB is now able to backtrace through the signal handler for
3267 non-threaded programs.
3269 PIE (Position Independent Executable) programs debugging is now supported.
3270 This includes debugging execution of PIC (Position Independent Code) shared
3271 libraries although for that, it should be possible to run such libraries as an
3274 *** Changes in GDB 7.0
3276 * GDB now has an interface for JIT compilation. Applications that
3277 dynamically generate code can create symbol files in memory and register
3278 them with GDB. For users, the feature should work transparently, and
3279 for JIT developers, the interface is documented in the GDB manual in the
3280 "JIT Compilation Interface" chapter.
3282 * Tracepoints may now be conditional. The syntax is as for
3283 breakpoints; either an "if" clause appended to the "trace" command,
3284 or the "condition" command is available. GDB sends the condition to
3285 the target for evaluation using the same bytecode format as is used
3286 for tracepoint actions.
3288 * The disassemble command now supports: an optional /r modifier, print the
3289 raw instructions in hex as well as in symbolic form, and an optional /m
3290 modifier to print mixed source+assembly.
3292 * Process record and replay
3294 In a architecture environment that supports ``process record and
3295 replay'', ``process record and replay'' target can record a log of
3296 the process execution, and replay it with both forward and reverse
3299 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3300 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3301 set execution-direction {forward|reverse}, for targets that support
3304 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3305 feature is available with a native GDB running on kernel version
3308 * GDB now has support for multi-byte and wide character sets on the
3309 target. Strings whose character type is wchar_t, char16_t, or
3310 char32_t are now correctly printed. GDB supports wide- and unicode-
3311 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3312 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3313 `printf'. This feature requires iconv to work properly; if your
3314 system does not have a working iconv, GDB can use GNU libiconv. See
3315 the installation instructions for more information.
3317 * GDB now supports automatic retrieval of shared library files from
3318 remote targets. To use this feature, specify a system root that begins
3319 with the `remote:' prefix, either via the `set sysroot' command or via
3320 the `--with-sysroot' configure-time option.
3322 * "info sharedlibrary" now takes an optional regex of libraries to show,
3323 and it now reports if a shared library has no debugging information.
3325 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3326 now complete on file names.
3328 * When completing in expressions, gdb will attempt to limit
3329 completions to allowable structure or union fields, where appropriate.
3330 For instance, consider:
3332 # struct example { int f1; double f2; };
3333 # struct example variable;
3336 If the user types TAB at the end of this command line, the available
3337 completions will be "f1" and "f2".
3339 * Inlined functions are now supported. They show up in backtraces, and
3340 the "step", "next", and "finish" commands handle them automatically.
3342 * GDB now supports the token-splicing (##) and stringification (#)
3343 operators when expanding macros. It also supports variable-arity
3346 * GDB now supports inspecting extra signal information, exported by
3347 the new $_siginfo convenience variable. The feature is currently
3348 implemented on linux ARM, i386 and amd64.
3350 * GDB can now display the VFP floating point registers and NEON vector
3351 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3352 can provide these registers (requires Linux 2.6.30 or later). Remote
3353 and simulator targets may also provide them.
3355 * New remote packets
3358 Search memory for a sequence of bytes.
3361 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3362 operation over reliable transport links. Use of this packet is
3363 controlled by the `set remote noack-packet' command.
3366 Kill the process with the specified process ID. Use this in preference
3367 to `k' when multiprocess protocol extensions are supported.
3370 Obtains additional operating system information
3374 Read or write additional signal information.
3376 * Removed remote protocol undocumented extension
3378 An undocumented extension to the remote protocol's `S' stop reply
3379 packet that permited the stub to pass a process id was removed.
3380 Remote servers should use the `T' stop reply packet instead.
3382 * GDB now supports multiple function calling conventions according to the
3383 DWARF-2 DW_AT_calling_convention function attribute.
3385 * The SH target utilizes the aforementioned change to distinguish between gcc
3386 and Renesas calling convention. It also adds the new CLI commands
3387 `set/show sh calling-convention'.
3389 * GDB can now read compressed debug sections, as produced by GNU gold
3390 with the --compress-debug-sections=zlib flag.
3392 * 64-bit core files are now supported on AIX.
3394 * Thread switching is now supported on Tru64.
3396 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3397 which will be allocated using malloc later in program execution.
3399 * The qXfer:libraries:read remote procotol packet now allows passing a
3400 list of section offsets.
3402 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3403 conditions handling signals delivered during attach or thread creation
3404 have also been fixed.
3406 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3407 From the user's standpoint, all unqualified instances of True and False
3408 are treated as the standard definitions, regardless of context.
3410 * GDB now parses C++ symbol and type names more flexibly. For
3413 template<typename T> class C { };
3416 GDB will now correctly handle all of:
3418 ptype C<char const *>
3419 ptype C<char const*>
3420 ptype C<const char *>
3421 ptype C<const char*>
3423 * New features in the GDB remote stub, gdbserver
3425 - The "--wrapper" command-line argument tells gdbserver to use a
3426 wrapper program to launch programs for debugging.
3428 - On PowerPC and S/390 targets, it is now possible to use a single
3429 gdbserver executable to debug both 32-bit and 64-bit programs.
3430 (This requires gdbserver itself to be built as a 64-bit executable.)
3432 - gdbserver uses the new noack protocol mode for TCP connections to
3433 reduce communications latency, if also supported and enabled in GDB.
3435 - Support for the sparc64-linux-gnu target is now included in
3438 - The amd64-linux build of gdbserver now supports debugging both
3439 32-bit and 64-bit programs.
3441 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3442 now support hardware watchpoints, and will use them automatically
3447 GDB now has support for scripting using Python. Whether this is
3448 available is determined at configure time.
3450 New GDB commands can now be written in Python.
3452 * Ada tasking support
3454 Ada tasks can now be inspected in GDB. The following commands have
3458 Print the list of Ada tasks.
3460 Print detailed information about task number N.
3462 Print the task number of the current task.
3464 Switch the context of debugging to task number N.
3466 * Support for user-defined prefixed commands. The "define" command can
3467 add new commands to existing prefixes, e.g. "target".
3469 * Multi-inferior, multi-process debugging.
3471 GDB now has generalized support for multi-inferior debugging. See
3472 "Debugging Multiple Inferiors" in the manual for more information.
3473 Although availability still depends on target support, the command
3474 set is more uniform now. The GNU/Linux specific multi-forks support
3475 has been migrated to this new framework. This implied some user
3476 visible changes; see "New commands" and also "Removed commands"
3479 * Target descriptions can now describe the target OS ABI. See the
3480 "Target Description Format" section in the user manual for more
3483 * Target descriptions can now describe "compatible" architectures
3484 to indicate that the target can execute applications for a different
3485 architecture in addition to those for the main target architecture.
3486 See the "Target Description Format" section in the user manual for
3489 * Multi-architecture debugging.
3491 GDB now includes general supports for debugging applications on
3492 hybrid systems that use more than one single processor architecture
3493 at the same time. Each such hybrid architecture still requires
3494 specific support to be added. The only hybrid architecture supported
3495 in this version of GDB is the Cell Broadband Engine.
3497 * GDB now supports integrated debugging of Cell/B.E. applications that
3498 use both the PPU and SPU architectures. To enable support for hybrid
3499 Cell/B.E. debugging, you need to configure GDB to support both the
3500 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3501 --enable-targets configure option.
3503 * Non-stop mode debugging.
3505 For some targets, GDB now supports an optional mode of operation in
3506 which you can examine stopped threads while other threads continue
3507 to execute freely. This is referred to as non-stop mode, with the
3508 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3509 section in the user manual for more information.
3511 To be able to support remote non-stop debugging, a remote stub needs
3512 to implement the non-stop mode remote protocol extensions, as
3513 described in the "Remote Non-Stop" section of the user manual. The
3514 GDB remote stub, gdbserver, has been adjusted to support these
3515 extensions on linux targets.
3517 * New commands (for set/show, see "New options" below)
3519 catch syscall [NAME(S) | NUMBER(S)]
3520 Catch system calls. Arguments, which should be names of system
3521 calls or their numbers, mean catch only those syscalls. Without
3522 arguments, every syscall will be caught. When the inferior issues
3523 any of the specified syscalls, GDB will stop and announce the system
3524 call, both when it is called and when its call returns. This
3525 feature is currently available with a native GDB running on the
3526 Linux Kernel, under the following architectures: x86, x86_64,
3527 PowerPC and PowerPC64.
3529 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3531 Search memory for a sequence of bytes.
3533 maint set python print-stack
3534 maint show python print-stack
3535 Show a stack trace when an error is encountered in a Python script.
3538 Invoke CODE by passing it to the Python interpreter.
3543 These allow macros to be defined, undefined, and listed
3547 Show operating system information about processes.
3550 List the inferiors currently under GDB's control.
3553 Switch focus to inferior number NUM.
3556 Detach from inferior number NUM.
3559 Kill inferior number NUM.
3563 set spu stop-on-load
3564 show spu stop-on-load
3565 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3567 set spu auto-flush-cache
3568 show spu auto-flush-cache
3569 Control whether to automatically flush the software-managed cache
3570 during Cell/B.E. debugging.
3572 set sh calling-convention
3573 show sh calling-convention
3574 Control the calling convention used when calling SH target functions.
3577 show debug timestamp
3578 Control display of timestamps with GDB debugging output.
3580 set disassemble-next-line
3581 show disassemble-next-line
3582 Control display of disassembled source lines or instructions when
3585 set remote noack-packet
3586 show remote noack-packet
3587 Set/show the use of remote protocol QStartNoAckMode packet. See above
3588 under "New remote packets."
3590 set remote query-attached-packet
3591 show remote query-attached-packet
3592 Control use of remote protocol `qAttached' (query-attached) packet.
3594 set remote read-siginfo-object
3595 show remote read-siginfo-object
3596 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3599 set remote write-siginfo-object
3600 show remote write-siginfo-object
3601 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3604 set remote reverse-continue
3605 show remote reverse-continue
3606 Control use of remote protocol 'bc' (reverse-continue) packet.
3608 set remote reverse-step
3609 show remote reverse-step
3610 Control use of remote protocol 'bs' (reverse-step) packet.
3612 set displaced-stepping
3613 show displaced-stepping
3614 Control displaced stepping mode. Displaced stepping is a way to
3615 single-step over breakpoints without removing them from the debuggee.
3616 Also known as "out-of-line single-stepping".
3619 show debug displaced
3620 Control display of debugging info for displaced stepping.
3622 maint set internal-error
3623 maint show internal-error
3624 Control what GDB does when an internal error is detected.
3626 maint set internal-warning
3627 maint show internal-warning
3628 Control what GDB does when an internal warning is detected.
3633 Use a wrapper program to launch programs for debugging.
3635 set multiple-symbols (all|ask|cancel)
3636 show multiple-symbols
3637 The value of this variable can be changed to adjust the debugger behavior
3638 when an expression or a breakpoint location contains an ambiguous symbol
3639 name (an overloaded function name, for instance).
3641 set breakpoint always-inserted
3642 show breakpoint always-inserted
3643 Keep breakpoints always inserted in the target, as opposed to inserting
3644 them when resuming the target, and removing them when the target stops.
3645 This option can improve debugger performance on slow remote targets.
3647 set arm fallback-mode (arm|thumb|auto)
3648 show arm fallback-mode
3649 set arm force-mode (arm|thumb|auto)
3651 These commands control how ARM GDB determines whether instructions
3652 are ARM or Thumb. The default for both settings is auto, which uses
3653 the current CPSR value for instructions without symbols; previous
3654 versions of GDB behaved as if "set arm fallback-mode arm".
3656 set disable-randomization
3657 show disable-randomization
3658 Standalone programs run with the virtual address space randomization enabled
3659 by default on some platforms. This option keeps the addresses stable across
3660 multiple debugging sessions.
3664 Control whether other threads are stopped or not when some thread hits
3669 Requests that asynchronous execution is enabled in the target, if available.
3670 In this case, it's possible to resume target in the background, and interact
3671 with GDB while the target is running. "show target-async" displays the
3672 current state of asynchronous execution of the target.
3674 set target-wide-charset
3675 show target-wide-charset
3676 The target-wide-charset is the name of the character set that GDB
3677 uses when printing characters whose type is wchar_t.
3679 set tcp auto-retry (on|off)
3681 set tcp connect-timeout
3682 show tcp connect-timeout
3683 These commands allow GDB to retry failed TCP connections to a remote stub
3684 with a specified timeout period; this is useful if the stub is launched
3685 in parallel with GDB but may not be ready to accept connections immediately.
3687 set libthread-db-search-path
3688 show libthread-db-search-path
3689 Control list of directories which GDB will search for appropriate
3692 set schedule-multiple (on|off)
3693 show schedule-multiple
3694 Allow GDB to resume all threads of all processes or only threads of
3695 the current process.
3699 Use more aggressive caching for accesses to the stack. This improves
3700 performance of remote debugging (particularly backtraces) without
3701 affecting correctness.
3703 set interactive-mode (on|off|auto)
3704 show interactive-mode
3705 Control whether GDB runs in interactive mode (on) or not (off).
3706 When in interactive mode, GDB waits for the user to answer all
3707 queries. Otherwise, GDB does not wait and assumes the default
3708 answer. When set to auto (the default), GDB determines which
3709 mode to use based on the stdin settings.
3714 For program forks, this is replaced by the new more generic `info
3715 inferiors' command. To list checkpoints, you can still use the
3716 `info checkpoints' command, which was an alias for the `info forks'
3720 Replaced by the new `inferior' command. To switch between
3721 checkpoints, you can still use the `restart' command, which was an
3722 alias for the `fork' command.
3725 This is removed, since some targets don't have a notion of
3726 processes. To switch between processes, you can still use the
3727 `inferior' command using GDB's own inferior number.
3730 For program forks, this is replaced by the new more generic `kill
3731 inferior' command. To delete a checkpoint, you can still use the
3732 `delete checkpoint' command, which was an alias for the `delete
3736 For program forks, this is replaced by the new more generic `detach
3737 inferior' command. To detach a checkpoint, you can still use the
3738 `detach checkpoint' command, which was an alias for the `detach
3741 * New native configurations
3743 x86/x86_64 Darwin i[34567]86-*-darwin*
3745 x86_64 MinGW x86_64-*-mingw*
3749 Lattice Mico32 lm32-*
3750 x86 DICOS i[34567]86-*-dicos*
3751 x86_64 DICOS x86_64-*-dicos*
3754 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3755 (mingw32ce) debugging.
3761 These commands were actually not implemented on any target.
3763 *** Changes in GDB 6.8
3765 * New native configurations
3767 NetBSD/hppa hppa*-*netbsd*
3768 Xtensa GNU/Linux xtensa*-*-linux*
3772 NetBSD/hppa hppa*-*-netbsd*
3773 Xtensa GNU/Lunux xtensa*-*-linux*
3775 * Change in command line behavior -- corefiles vs. process ids.
3777 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3778 attaching to process NUMBER fails, GDB no longer attempts to open a
3779 core file named NUMBER. Attaching to a program using the -c option
3780 is no longer supported. Instead, use the '-p' or '--pid' options.
3782 * GDB can now be built as a native debugger for debugging Windows x86
3783 (mingw32) Portable Executable (PE) programs.
3785 * Pending breakpoints no longer change their number when their address
3788 * GDB now supports breakpoints with multiple locations,
3789 including breakpoints on C++ constructors, inside C++ templates,
3790 and in inlined functions.
3792 * GDB's ability to debug optimized code has been improved. GDB more
3793 accurately identifies function bodies and lexical blocks that occupy
3794 more than one contiguous range of addresses.
3796 * Target descriptions can now describe registers for PowerPC.
3798 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3799 registers on PowerPC targets.
3801 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3802 targets even when the libthread_db library is not available.
3804 * The GDB remote stub, gdbserver, now supports the new file transfer
3805 commands (remote put, remote get, and remote delete).
3807 * The GDB remote stub, gdbserver, now supports run and attach in
3808 extended-remote mode.
3810 * hppa*64*-*-hpux11* target broken
3811 The debugger is unable to start a program and fails with the following
3812 error: "Error trying to get information about dynamic linker".
3813 The gdb-6.7 release is also affected.
3815 * GDB now supports the --enable-targets= configure option to allow
3816 building a single GDB executable that supports multiple remote
3817 target architectures.
3819 * GDB now supports debugging C and C++ programs which use the
3820 Decimal Floating Point extension. In addition, the PowerPC target
3821 now has a set of pseudo-registers to inspect decimal float values
3822 stored in two consecutive float registers.
3824 * The -break-insert MI command can optionally create pending
3827 * Improved support for debugging Ada
3828 Many improvements to the Ada language support have been made. These
3830 - Better support for Ada2005 interface types
3831 - Improved handling of arrays and slices in general
3832 - Better support for Taft-amendment types
3833 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3835 - Improved command completion in Ada
3838 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3843 set print frame-arguments (all|scalars|none)
3844 show print frame-arguments
3845 The value of this variable can be changed to control which argument
3846 values should be printed by the debugger when displaying a frame.
3851 Transfer files to and from a remote target, and delete remote files.
3858 Transfer files to and from a remote target, and delete remote files.
3860 * New remote packets
3867 Open, close, read, write, and delete files on the remote system.
3870 Attach to an existing process on the remote system, in extended-remote
3874 Run a new process on the remote system, in extended-remote mode.
3876 *** Changes in GDB 6.7
3878 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3879 bfd, libiberty and opcodes, as revealed by static analysis donated by
3880 Coverity, Inc. (http://scan.coverity.com).
3882 * When looking up multiply-defined global symbols, GDB will now prefer the
3883 symbol definition in the current shared library if it was built using the
3884 -Bsymbolic linker option.
3886 * When the Text User Interface (TUI) is not configured, GDB will now
3887 recognize the -tui command-line option and print a message that the TUI
3890 * The GDB remote stub, gdbserver, now has lower overhead for high
3891 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3893 * GDB for MIPS targets now autodetects whether a remote target provides
3894 32-bit or 64-bit register values.
3896 * Support for C++ member pointers has been improved.
3898 * GDB now understands XML target descriptions, which specify the
3899 target's overall architecture. GDB can read a description from
3900 a local file or over the remote serial protocol.
3902 * Vectors of single-byte data use a new integer type which is not
3903 automatically displayed as character or string data.
3905 * The /s format now works with the print command. It displays
3906 arrays of single-byte integers and pointers to single-byte integers
3909 * Target descriptions can now describe target-specific registers,
3910 for architectures which have implemented the support (currently
3911 only ARM, M68K, and MIPS).
3913 * GDB and the GDB remote stub, gdbserver, now support the XScale
3916 * The GDB remote stub, gdbserver, has been updated to support
3917 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3918 has been rewritten to use the standard GDB remote protocol.
3920 * GDB can now step into C++ functions which are called through thunks.
3922 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3924 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3925 layout. It also supports a TextSeg= and DataSeg= response when only
3926 segment base addresses (rather than offsets) are available.
3928 * The /i format now outputs any trailing branch delay slot instructions
3929 immediately following the last instruction within the count specified.
3931 * The GDB remote protocol "T" stop reply packet now supports a
3932 "library" response. Combined with the new "qXfer:libraries:read"
3933 packet, this response allows GDB to debug shared libraries on targets
3934 where the operating system manages the list of loaded libraries (e.g.
3935 Windows and SymbianOS).
3937 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3938 (DLLs) on Windows and Windows CE targets.
3940 * GDB now supports a faster verification that a .debug file matches its binary
3941 according to its build-id signature, if the signature is present.
3947 Enable or disable hardware flow control (RTS/CTS) on the serial port
3948 when debugging using remote targets.
3950 set mem inaccessible-by-default
3951 show mem inaccessible-by-default
3952 If the target supplies a memory map, for instance via the remote
3953 protocol's "qXfer:memory-map:read" packet, setting this variable
3954 prevents GDB from accessing memory outside the memory map. This
3955 is useful for targets with memory mapped registers or which react
3956 badly to accesses of unmapped address space.
3958 set breakpoint auto-hw
3959 show breakpoint auto-hw
3960 If the target supplies a memory map, for instance via the remote
3961 protocol's "qXfer:memory-map:read" packet, setting this variable
3962 lets GDB use hardware breakpoints automatically for memory regions
3963 where it can not use software breakpoints. This covers both the
3964 "break" command and internal breakpoints used for other commands
3965 including "next" and "finish".
3968 catch exception unhandled
3969 Stop the program execution when Ada exceptions are raised.
3972 Stop the program execution when an Ada assertion failed.
3976 Set an alternate system root for target files. This is a more
3977 general version of "set solib-absolute-prefix", which is now
3978 an alias to "set sysroot".
3981 Provide extended SPU facility status information. This set of
3982 commands is available only when debugging the Cell/B.E. SPU
3985 * New native configurations
3987 OpenBSD/sh sh*-*openbsd*
3990 unset tdesc filename
3992 Use the specified local file as an XML target description, and do
3993 not query the target for its built-in description.
3997 OpenBSD/sh sh*-*-openbsd*
3998 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3999 Toshiba Media Processor mep-elf
4001 * New remote packets
4004 Ignore the specified signals; pass them directly to the debugged program
4005 without stopping other threads or reporting them to GDB.
4007 qXfer:features:read:
4008 Read an XML target description from the target, which describes its
4013 Read or write contents of an spufs file on the target system. These
4014 packets are available only on the Cell/B.E. SPU architecture.
4016 qXfer:libraries:read:
4017 Report the loaded shared libraries. Combined with new "T" packet
4018 response, this packet allows GDB to debug shared libraries on
4019 targets where the operating system manages the list of loaded
4020 libraries (e.g. Windows and SymbianOS).
4024 Support for these obsolete configurations has been removed.
4032 i[34567]86-*-lynxos*
4033 i[34567]86-*-netware*
4034 i[34567]86-*-sco3.2v5*
4035 i[34567]86-*-sco3.2v4*
4037 i[34567]86-*-sysv4.2*
4040 i[34567]86-*-unixware2*
4041 i[34567]86-*-unixware*
4050 * Other removed features
4057 Various m68k-only ROM monitors.
4064 Various Renesas ROM monitors and debugging interfaces for SH and
4069 Support for a Macraigor serial interface to on-chip debugging.
4070 GDB does not directly support the newer parallel or USB
4075 A debug information format. The predecessor to DWARF 2 and
4076 DWARF 3, which are still supported.
4078 Support for the HP aCC compiler on HP-UX/PA-RISC
4080 SOM-encapsulated symbolic debugging information, automatic
4081 invocation of pxdb, and the aCC custom C++ ABI. This does not
4082 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4083 with aCC can still be debugged on an assembly level.
4085 MIPS ".pdr" sections
4087 A MIPS-specific format used to describe stack frame layout
4088 in debugging information.
4092 GDB could work with an older version of Guile to debug
4093 the interpreter and Scheme programs running in it.
4095 set mips stack-arg-size
4096 set mips saved-gpreg-size
4098 Use "set mips abi" to control parameter passing for MIPS.
4100 *** Changes in GDB 6.6
4105 Cell Broadband Engine SPU spu-elf
4107 * GDB can now be configured as a cross-debugger targeting native Windows
4108 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4109 running on a Windows system over TCP/IP to debug Windows programs.
4111 * The GDB remote stub, gdbserver, has been updated to support Windows and
4112 Cygwin debugging. Both single-threaded and multi-threaded programs are
4115 * The "set trust-readonly-sections" command works again. This command was
4116 broken in GDB 6.3, 6.4, and 6.5.
4118 * The "load" command now supports writing to flash memory, if the remote
4119 stub provides the required support.
4121 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4122 longer requires symbolic debug information (e.g. DWARF-2).
4127 unset substitute-path
4128 show substitute-path
4129 Manage a list of substitution rules that GDB uses to rewrite the name
4130 of the directories where the sources are located. This can be useful
4131 for instance when the sources were moved to a different location
4132 between compilation and debugging.
4136 Print each CLI command as it is executed. Each command is prefixed with
4137 a number of `+' symbols representing the nesting depth.
4138 The source command now has a `-v' option to enable the same feature.
4142 The ARM Demon monitor support (RDP protocol, "target rdp").
4144 Kernel Object Display, an embedded debugging feature which only worked with
4145 an obsolete version of Cisco IOS.
4147 The 'set download-write-size' and 'show download-write-size' commands.
4149 * New remote packets
4152 Tell a stub about GDB client features, and request remote target features.
4153 The first feature implemented is PacketSize, which allows the target to
4154 specify the size of packets it can handle - to minimize the number of
4155 packets required and improve performance when connected to a remote
4159 Fetch an OS auxilliary vector from the remote stub. This packet is a
4160 more efficient replacement for qPart:auxv:read.
4162 qXfer:memory-map:read:
4163 Fetch a memory map from the remote stub, including information about
4164 RAM, ROM, and flash memory devices.
4169 Erase and program a flash memory device.
4171 * Removed remote packets
4174 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4175 used it, and only gdbserver implemented it.
4177 *** Changes in GDB 6.5
4181 Renesas M32C/M16C m32c-elf
4183 Morpho Technologies ms1 ms1-elf
4187 init-if-undefined Initialize a convenience variable, but
4188 only if it doesn't already have a value.
4190 The following commands are presently only implemented for native GNU/Linux:
4192 checkpoint Save a snapshot of the program state.
4194 restart <n> Return the program state to a
4195 previously saved state.
4197 info checkpoints List currently saved checkpoints.
4199 delete-checkpoint <n> Delete a previously saved checkpoint.
4201 set|show detach-on-fork Tell gdb whether to detach from a newly
4202 forked process, or to keep debugging it.
4204 info forks List forks of the user program that
4205 are available to be debugged.
4207 fork <n> Switch to debugging one of several
4208 forks of the user program that are
4209 available to be debugged.
4211 delete-fork <n> Delete a fork from the list of forks
4212 that are available to be debugged (and
4213 kill the forked process).
4215 detach-fork <n> Delete a fork from the list of forks
4216 that are available to be debugged (and
4217 allow the process to continue).
4221 Morpho Technologies ms2 ms1-elf
4223 * Improved Windows host support
4225 GDB now builds as a cross debugger hosted on i686-mingw32, including
4226 native console support, and remote communications using either
4227 network sockets or serial ports.
4229 * Improved Modula-2 language support
4231 GDB can now print most types in the Modula-2 syntax. This includes:
4232 basic types, set types, record types, enumerated types, range types,
4233 pointer types and ARRAY types. Procedure var parameters are correctly
4234 printed and hexadecimal addresses and character constants are also
4235 written in the Modula-2 syntax. Best results can be obtained by using
4236 GNU Modula-2 together with the -gdwarf-2 command line option.
4240 The ARM rdi-share module.
4242 The Netware NLM debug server.
4244 *** Changes in GDB 6.4
4246 * New native configurations
4248 OpenBSD/arm arm*-*-openbsd*
4249 OpenBSD/mips64 mips64-*-openbsd*
4253 Morpho Technologies ms1 ms1-elf
4255 * New command line options
4257 --batch-silent As for --batch, but totally silent.
4258 --return-child-result The debugger will exist with the same value
4259 the child (debugged) program exited with.
4260 --eval-command COMMAND, -ex COMMAND
4261 Execute a single GDB CLI command. This may be
4262 specified multiple times and in conjunction
4263 with the --command (-x) option.
4265 * Deprecated commands removed
4267 The following commands, that were deprecated in 2000, have been
4271 set|show arm disassembly-flavor set|show arm disassembler
4272 othernames set arm disassembler
4273 set|show remotedebug set|show debug remote
4274 set|show archdebug set|show debug arch
4275 set|show eventdebug set|show debug event
4278 * New BSD user-level threads support
4280 It is now possible to debug programs using the user-level threads
4281 library on OpenBSD and FreeBSD. Currently supported (target)
4284 FreeBSD/amd64 x86_64-*-freebsd*
4285 FreeBSD/i386 i386-*-freebsd*
4286 OpenBSD/i386 i386-*-openbsd*
4288 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4289 are not yet supported.
4291 * New support for Matsushita MN10300 w/sim added
4292 (Work in progress). mn10300-elf.
4294 * REMOVED configurations and files
4296 VxWorks and the XDR protocol *-*-vxworks
4297 Motorola MCORE mcore-*-*
4298 National Semiconductor NS32000 ns32k-*-*
4300 * New "set print array-indexes" command
4302 After turning this setting "on", GDB prints the index of each element
4303 when displaying arrays. The default is "off" to preserve the previous
4306 * VAX floating point support
4308 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4310 * User-defined command support
4312 In addition to using $arg0..$arg9 for argument passing, it is now possible
4313 to use $argc to determine now many arguments have been passed. See the
4314 section on user-defined commands in the user manual for more information.
4316 *** Changes in GDB 6.3:
4318 * New command line option
4320 GDB now accepts -l followed by a number to set the timeout for remote
4323 * GDB works with GCC -feliminate-dwarf2-dups
4325 GDB now supports a more compact representation of DWARF-2 debug
4326 information using DW_FORM_ref_addr references. These are produced
4327 by GCC with the option -feliminate-dwarf2-dups and also by some
4328 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4329 to use -feliminate-dwarf2-dups.
4331 * Internationalization
4333 When supported by the host system, GDB will be built with
4334 internationalization (libintl). The task of marking up the sources is
4335 continued, we're looking forward to our first translation.
4339 Initial support for debugging programs compiled with the GNAT
4340 implementation of the Ada programming language has been integrated
4341 into GDB. In this release, support is limited to expression evaluation.
4343 * New native configurations
4345 GNU/Linux/m32r m32r-*-linux-gnu
4349 GDB's remote protocol now includes support for the 'p' packet. This
4350 packet is used to fetch individual registers from a remote inferior.
4352 * END-OF-LIFE registers[] compatibility module
4354 GDB's internal register infrastructure has been completely rewritten.
4355 The new infrastructure making possible the implementation of key new
4356 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4359 GDB 6.3 will be the last release to include the the registers[]
4360 compatibility module that allowed out-of-date configurations to
4361 continue to work. This change directly impacts the following
4371 powerpc bdm protocol
4373 Unless there is activity to revive these configurations, they will be
4374 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4376 * OBSOLETE configurations and files
4378 Configurations that have been declared obsolete in this release have
4379 been commented out. Unless there is activity to revive these
4380 configurations, the next release of GDB will have their sources
4381 permanently REMOVED.
4390 *** Changes in GDB 6.2.1:
4392 * MIPS `break main; run' gave an heuristic-fence-post warning
4394 When attempting to run even a simple program, a warning about
4395 heuristic-fence-post being hit would be reported. This problem has
4398 * MIPS IRIX 'long double' crashed GDB
4400 When examining a long double variable, GDB would get a segmentation
4401 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4402 IRIX long double values).
4406 A bug in the VAX stack code was causing problems with the "next"
4407 command. This problem has been fixed.
4409 *** Changes in GDB 6.2:
4411 * Fix for ``many threads''
4413 On GNU/Linux systems that use the NPTL threads library, a program
4414 rapidly creating and deleting threads would confuse GDB leading to the
4417 ptrace: No such process.
4418 thread_db_get_info: cannot get thread info: generic error
4420 This problem has been fixed.
4422 * "-async" and "-noasync" options removed.
4424 Support for the broken "-noasync" option has been removed (it caused
4427 * New ``start'' command.
4429 This command runs the program until the begining of the main procedure.
4431 * New BSD Kernel Data Access Library (libkvm) interface
4433 Using ``target kvm'' it is now possible to debug kernel core dumps and
4434 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4435 platforms. Currently supported (native-only) configurations are:
4437 FreeBSD/amd64 x86_64-*-freebsd*
4438 FreeBSD/i386 i?86-*-freebsd*
4439 NetBSD/i386 i?86-*-netbsd*
4440 NetBSD/m68k m68*-*-netbsd*
4441 NetBSD/sparc sparc-*-netbsd*
4442 OpenBSD/amd64 x86_64-*-openbsd*
4443 OpenBSD/i386 i?86-*-openbsd*
4444 OpenBSD/m68k m68*-openbsd*
4445 OpenBSD/sparc sparc-*-openbsd*
4447 * Signal trampoline code overhauled
4449 Many generic problems with GDB's signal handling code have been fixed.
4450 These include: backtraces through non-contiguous stacks; recognition
4451 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4452 call; backtrace through a signal trampoline; step into and out of
4453 signal handlers; and single-stepping in the signal trampoline.
4455 Please note that kernel bugs are a limiting factor here. These
4456 features have been shown to work on an s390 GNU/Linux system that
4457 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4459 * Cygwin support for DWARF 2 added.
4461 * New native configurations
4463 GNU/Linux/hppa hppa*-*-linux*
4464 OpenBSD/hppa hppa*-*-openbsd*
4465 OpenBSD/m68k m68*-*-openbsd*
4466 OpenBSD/m88k m88*-*-openbsd*
4467 OpenBSD/powerpc powerpc-*-openbsd*
4468 NetBSD/vax vax-*-netbsd*
4469 OpenBSD/vax vax-*-openbsd*
4471 * END-OF-LIFE frame compatibility module
4473 GDB's internal frame infrastructure has been completely rewritten.
4474 The new infrastructure making it possible to support key new features
4475 including DWARF 2 Call Frame Information. To aid in the task of
4476 migrating old configurations to this new infrastructure, a
4477 compatibility module, that allowed old configurations to continue to
4478 work, was also included.
4480 GDB 6.2 will be the last release to include this frame compatibility
4481 module. This change directly impacts the following configurations:
4491 Unless there is activity to revive these configurations, they will be
4492 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4494 * REMOVED configurations and files
4496 Sun 3, running SunOS 3 m68*-*-sunos3*
4497 Sun 3, running SunOS 4 m68*-*-sunos4*
4498 Sun 2, running SunOS 3 m68000-*-sunos3*
4499 Sun 2, running SunOS 4 m68000-*-sunos4*
4500 Motorola 680x0 running LynxOS m68*-*-lynxos*
4501 AT&T 3b1/Unix pc m68*-att-*
4502 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4503 decstation mips-dec-* mips-little-*
4504 riscos mips-*-riscos* mips-*-sysv*
4505 sonymips mips-sony-*
4506 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4508 *** Changes in GDB 6.1.1:
4510 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4512 The TUI (Text-mode User Interface) is now built as part of a default
4513 GDB configuration. It is enabled by either selecting the TUI with the
4514 command line option "-i=tui" or by running the separate "gdbtui"
4515 program. For more information on the TUI, see the manual "Debugging
4518 * Pending breakpoint support (also included in GDB 6.1)
4520 Support has been added to allow you to specify breakpoints in shared
4521 libraries that have not yet been loaded. If a breakpoint location
4522 cannot be found, and the "breakpoint pending" option is set to auto,
4523 GDB queries you if you wish to make the breakpoint pending on a future
4524 shared-library load. If and when GDB resolves the breakpoint symbol,
4525 the pending breakpoint is removed as one or more regular breakpoints
4528 Pending breakpoints are very useful for GCJ Java debugging.
4530 * Fixed ISO-C build problems
4532 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4533 non ISO-C code that stopped them being built using a more strict ISO-C
4534 compiler (e.g., IBM's C compiler).
4536 * Fixed build problem on IRIX 5
4538 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4539 wasn't able to compile compile on an IRIX 5 system.
4541 * Added execute permission to gdb/gdbserver/configure
4543 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4544 permission. This bug would cause configure to fail on a number of
4545 systems (Solaris, IRIX). Ref: server/519.
4547 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4549 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4550 has been updated to use constant array sizes.
4552 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4554 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4555 its generated DWARF Call Frame Info. This encoding was causing GDB to
4556 panic, that panic has been fixed. Ref: gdb/1628.
4558 * Fixed a problem when examining parameters in shared library code.
4560 When examining parameters in optimized shared library code generated
4561 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4562 not available''. GDB now correctly displays the variable's value.
4564 *** Changes in GDB 6.1:
4566 * Removed --with-mmalloc
4568 Support for the mmalloc memory manager has been removed, as it
4569 conflicted with the internal gdb byte cache.
4571 * Changes in AMD64 configurations
4573 The AMD64 target now includes the %cs and %ss registers. As a result
4574 the AMD64 remote protocol has changed; this affects the floating-point
4575 and SSE registers. If you rely on those registers for your debugging,
4576 you should upgrade gdbserver on the remote side.
4578 * Revised SPARC target
4580 The SPARC target has been completely revised, incorporating the
4581 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4582 support for LynxOS and SunOS 4 has been dropped. Calling functions
4583 from within GDB on operating systems with a non-executable stack
4584 (Solaris, OpenBSD) now works.
4588 GDB has a new C++ demangler which does a better job on the mangled
4589 names generated by current versions of g++. It also runs faster, so
4590 with this and other changes gdb should now start faster on large C++
4593 * DWARF 2 Location Expressions
4595 GDB support for location expressions has been extended to support function
4596 arguments and frame bases. Older versions of GDB could crash when they
4599 * C++ nested types and namespaces
4601 GDB's support for nested types and namespaces in C++ has been
4602 improved, especially if you use the DWARF 2 debugging format. (This
4603 is the default for recent versions of GCC on most platforms.)
4604 Specifically, if you have a class "Inner" defined within a class or
4605 namespace "Outer", then GDB realizes that the class's name is
4606 "Outer::Inner", not simply "Inner". This should greatly reduce the
4607 frequency of complaints about not finding RTTI symbols. In addition,
4608 if you are stopped at inside of a function defined within a namespace,
4609 GDB modifies its name lookup accordingly.
4611 * New native configurations
4613 NetBSD/amd64 x86_64-*-netbsd*
4614 OpenBSD/amd64 x86_64-*-openbsd*
4615 OpenBSD/alpha alpha*-*-openbsd*
4616 OpenBSD/sparc sparc-*-openbsd*
4617 OpenBSD/sparc64 sparc64-*-openbsd*
4619 * New debugging protocols
4621 M32R with SDI protocol m32r-*-elf*
4623 * "set prompt-escape-char" command deleted.
4625 The command "set prompt-escape-char" has been deleted. This command,
4626 and its very obscure effet on GDB's prompt, was never documented,
4627 tested, nor mentioned in the NEWS file.
4629 * OBSOLETE configurations and files
4631 Configurations that have been declared obsolete in this release have
4632 been commented out. Unless there is activity to revive these
4633 configurations, the next release of GDB will have their sources
4634 permanently REMOVED.
4636 Sun 3, running SunOS 3 m68*-*-sunos3*
4637 Sun 3, running SunOS 4 m68*-*-sunos4*
4638 Sun 2, running SunOS 3 m68000-*-sunos3*
4639 Sun 2, running SunOS 4 m68000-*-sunos4*
4640 Motorola 680x0 running LynxOS m68*-*-lynxos*
4641 AT&T 3b1/Unix pc m68*-att-*
4642 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4643 decstation mips-dec-* mips-little-*
4644 riscos mips-*-riscos* mips-*-sysv*
4645 sonymips mips-sony-*
4646 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4648 * REMOVED configurations and files
4650 SGI Irix-4.x mips-sgi-irix4 or iris4
4651 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4652 Z8000 simulator z8k-zilog-none or z8ksim
4653 Matsushita MN10200 w/simulator mn10200-*-*
4654 H8/500 simulator h8500-hitachi-hms or h8500hms
4655 HP/PA running BSD hppa*-*-bsd*
4656 HP/PA running OSF/1 hppa*-*-osf*
4657 HP/PA Pro target hppa*-*-pro*
4658 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4659 386BSD i[3456]86-*-bsd*
4660 Sequent family i[3456]86-sequent-sysv4*
4661 i[3456]86-sequent-sysv*
4662 i[3456]86-sequent-bsd*
4663 SPARC running LynxOS sparc-*-lynxos*
4664 SPARC running SunOS 4 sparc-*-sunos4*
4665 Tsqware Sparclet sparclet-*-*
4666 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4668 *** Changes in GDB 6.0:
4672 Support for debugging the Objective-C programming language has been
4673 integrated into GDB.
4675 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4677 DWARF 2's Call Frame Information makes available compiler generated
4678 information that more exactly describes the program's run-time stack.
4679 By using this information, GDB is able to provide more robust stack
4682 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4683 have been updated to use a new backtrace mechanism which includes
4684 DWARF 2 CFI support.
4688 GDB's remote protocol has been extended to include support for hosted
4689 file I/O (where the remote target uses GDB's file system). See GDB's
4690 remote protocol documentation for details.
4692 * All targets using the new architecture framework.
4694 All of GDB's targets have been updated to use the new internal
4695 architecture framework. The way is now open for future GDB releases
4696 to include cross-architecture native debugging support (i386 on amd64,
4699 * GNU/Linux's Thread Local Storage (TLS)
4701 GDB now includes support for for the GNU/Linux implementation of
4702 per-thread variables.
4704 * GNU/Linux's Native POSIX Thread Library (NPTL)
4706 GDB's thread code has been updated to work with either the new
4707 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4709 * Separate debug info.
4711 GDB, in conjunction with BINUTILS, now supports a mechanism for
4712 automatically loading debug information from a separate file. Instead
4713 of shipping full debug and non-debug versions of system libraries,
4714 system integrators can now instead ship just the stripped libraries
4715 and optional debug files.
4717 * DWARF 2 Location Expressions
4719 DWARF 2 Location Expressions allow the compiler to more completely
4720 describe the location of variables (even in optimized code) to the
4723 GDB now includes preliminary support for location expressions (support
4724 for DW_OP_piece is still missing).
4728 A number of long standing bugs that caused GDB to die while starting a
4729 Java application have been fixed. GDB's Java support is now
4730 considered "useable".
4732 * GNU/Linux support for fork, vfork, and exec.
4734 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4735 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4738 * GDB supports logging output to a file
4740 There are two new commands, "set logging" and "show logging", which can be
4741 used to capture GDB's output to a file.
4743 * The meaning of "detach" has changed for gdbserver
4745 The "detach" command will now resume the application, as documented. To
4746 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4749 * d10v, m68hc11 `regs' command deprecated
4751 The `info registers' command has been updated so that it displays the
4752 registers using a format identical to the old `regs' command.
4756 A new command, "maint set profile on/off", has been added. This command can
4757 be used to enable or disable profiling while running GDB, to profile a
4758 session or a set of commands. In addition there is a new configure switch,
4759 "--enable-profiling", which will cause GDB to be compiled with profiling
4760 data, for more informative profiling results.
4762 * Default MI syntax changed to "mi2".
4764 The default MI (machine interface) syntax, enabled by the command line
4765 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4766 "mi1", can be enabled by specifying the option "-i=mi1".
4768 Support for the original "mi0" syntax (included in GDB 5.0) has been
4771 Fix for gdb/192: removed extraneous space when displaying frame level.
4772 Fix for gdb/672: update changelist is now output in mi list format.
4773 Fix for gdb/702: a -var-assign that updates the value now shows up
4774 in a subsequent -var-update.
4776 * New native configurations.
4778 FreeBSD/amd64 x86_64-*-freebsd*
4780 * Multi-arched targets.
4782 HP/PA HPUX11 hppa*-*-hpux*
4783 Renesas M32R/D w/simulator m32r-*-elf*
4785 * OBSOLETE configurations and files
4787 Configurations that have been declared obsolete in this release have
4788 been commented out. Unless there is activity to revive these
4789 configurations, the next release of GDB will have their sources
4790 permanently REMOVED.
4792 Z8000 simulator z8k-zilog-none or z8ksim
4793 Matsushita MN10200 w/simulator mn10200-*-*
4794 H8/500 simulator h8500-hitachi-hms or h8500hms
4795 HP/PA running BSD hppa*-*-bsd*
4796 HP/PA running OSF/1 hppa*-*-osf*
4797 HP/PA Pro target hppa*-*-pro*
4798 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4799 Sequent family i[3456]86-sequent-sysv4*
4800 i[3456]86-sequent-sysv*
4801 i[3456]86-sequent-bsd*
4802 Tsqware Sparclet sparclet-*-*
4803 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4805 * REMOVED configurations and files
4808 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4809 IBM AIX PS/2 i[3456]86-*-aix
4810 i386 running Mach 3.0 i[3456]86-*-mach3*
4811 i386 running Mach i[3456]86-*-mach*
4812 i386 running OSF/1 i[3456]86-*osf1mk*
4813 HP/Apollo 68k Family m68*-apollo*-sysv*,
4815 m68*-hp-bsd*, m68*-hp-hpux*
4816 Argonaut Risc Chip (ARC) arc-*-*
4817 Mitsubishi D30V d30v-*-*
4818 Fujitsu FR30 fr30-*-elf*
4819 OS/9000 i[34]86-*-os9k
4820 I960 with MON960 i960-*-coff
4822 * MIPS $fp behavior changed
4824 The convenience variable $fp, for the MIPS, now consistently returns
4825 the address of the current frame's base. Previously, depending on the
4826 context, $fp could refer to either $sp or the current frame's base
4827 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4828 The GNU Source-Level Debugger''.
4830 *** Changes in GDB 5.3:
4832 * GNU/Linux shared library multi-threaded performance improved.
4834 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4835 `/proc', in preference to `ptrace' for memory reads. This may result
4836 in an improvement in the start-up time of multi-threaded, shared
4837 library applications when run under GDB. One GDB user writes: ``loads
4838 shared libs like mad''.
4840 * ``gdbserver'' now supports multi-threaded applications on some targets
4842 Support for debugging multi-threaded applications which use
4843 the GNU/Linux LinuxThreads package has been added for
4844 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4845 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4847 * GDB now supports C/C++ preprocessor macros.
4849 GDB now expands preprocessor macro invocations in C/C++ expressions,
4850 and provides various commands for showing macro definitions and how
4853 The new command `macro expand EXPRESSION' expands any macro
4854 invocations in expression, and shows the result.
4856 The new command `show macro MACRO-NAME' shows the definition of the
4857 macro named MACRO-NAME, and where it was defined.
4859 Most compilers don't include information about macros in the debugging
4860 information by default. In GCC 3.1, for example, you need to compile
4861 your program with the options `-gdwarf-2 -g3'. If the macro
4862 information is present in the executable, GDB will read it.
4864 * Multi-arched targets.
4866 DEC Alpha (partial) alpha*-*-*
4867 DEC VAX (partial) vax-*-*
4869 National Semiconductor NS32000 (partial) ns32k-*-*
4870 Motorola 68000 (partial) m68k-*-*
4871 Motorola MCORE mcore-*-*
4875 Fujitsu FRV architecture added by Red Hat frv*-*-*
4878 * New native configurations
4880 Alpha NetBSD alpha*-*-netbsd*
4881 SH NetBSD sh*-*-netbsdelf*
4882 MIPS NetBSD mips*-*-netbsd*
4883 UltraSPARC NetBSD sparc64-*-netbsd*
4885 * OBSOLETE configurations and files
4887 Configurations that have been declared obsolete in this release have
4888 been commented out. Unless there is activity to revive these
4889 configurations, the next release of GDB will have their sources
4890 permanently REMOVED.
4892 Mitsubishi D30V d30v-*-*
4893 OS/9000 i[34]86-*-os9k
4894 IBM AIX PS/2 i[3456]86-*-aix
4895 Fujitsu FR30 fr30-*-elf*
4896 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4897 Argonaut Risc Chip (ARC) arc-*-*
4898 i386 running Mach 3.0 i[3456]86-*-mach3*
4899 i386 running Mach i[3456]86-*-mach*
4900 i386 running OSF/1 i[3456]86-*osf1mk*
4901 HP/Apollo 68k Family m68*-apollo*-sysv*,
4903 m68*-hp-bsd*, m68*-hp-hpux*
4904 I960 with MON960 i960-*-coff
4906 * OBSOLETE languages
4908 CHILL, a Pascal like language used by telecommunications companies.
4910 * REMOVED configurations and files
4912 AMD 29k family via UDI a29k-amd-udi, udi29k
4913 A29K VxWorks a29k-*-vxworks
4914 AMD 29000 embedded, using EBMON a29k-none-none
4915 AMD 29000 embedded with COFF a29k-none-coff
4916 AMD 29000 embedded with a.out a29k-none-aout
4918 testsuite/gdb.hp/gdb.threads-hp/ directory
4920 * New command "set max-user-call-depth <nnn>"
4922 This command allows the user to limit the call depth of user-defined
4923 commands. The default is 1024.
4925 * Changes in FreeBSD/i386 native debugging.
4927 Support for the "generate-core-file" has been added.
4929 * New commands "dump", "append", and "restore".
4931 These commands allow data to be copied from target memory
4932 to a bfd-format or binary file (dump and append), and back
4933 from a file into memory (restore).
4935 * Improved "next/step" support on multi-processor Alpha Tru64.
4937 The previous single-step mechanism could cause unpredictable problems,
4938 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4939 of a software single-step mechanism prevents this.
4941 *** Changes in GDB 5.2.1:
4949 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4950 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4951 Fix, by Joel Brobecker imported from mainline.
4953 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4954 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4955 Fix, by Fred Fish, imported from mainline.
4957 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4958 Surprisingly enough, it works now.
4959 By Michal Ludvig, imported from mainline.
4961 i386 hardware watchpoint support:
4962 avoid misses on second run for some targets.
4963 By Pierre Muller, imported from mainline.
4965 *** Changes in GDB 5.2:
4967 * New command "set trust-readonly-sections on[off]".
4969 This command is a hint that tells gdb that read-only sections
4970 really are read-only (ie. that their contents will not change).
4971 In this mode, gdb will go to the object file rather than the
4972 target to read memory from read-only sections (such as ".text").
4973 This can be a significant performance improvement on some
4974 (notably embedded) targets.
4976 * New command "generate-core-file" (or "gcore").
4978 This new gdb command allows the user to drop a core file of the child
4979 process state at any time. So far it's been implemented only for
4980 GNU/Linux and Solaris, but should be relatively easily ported to other
4981 hosts. Argument is core file name (defaults to core.<pid>).
4983 * New command line option
4985 GDB now accepts --pid or -p followed by a process id.
4987 * Change in command line behavior -- corefiles vs. process ids.
4989 There is a subtle behavior in the way in which GDB handles
4990 command line arguments. The first non-flag argument is always
4991 a program to debug, but the second non-flag argument may either
4992 be a corefile or a process id. Previously, GDB would attempt to
4993 open the second argument as a corefile, and if that failed, would
4994 issue a superfluous error message and then attempt to attach it as
4995 a process. Now, if the second argument begins with a non-digit,
4996 it will be treated as a corefile. If it begins with a digit,
4997 GDB will attempt to attach it as a process, and if no such process
4998 is found, will then attempt to open it as a corefile.
5000 * Changes in ARM configurations.
5002 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5003 configuration is fully multi-arch.
5005 * New native configurations
5007 ARM NetBSD arm*-*-netbsd*
5008 x86 OpenBSD i[3456]86-*-openbsd*
5009 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5010 Sparc64 running FreeBSD sparc64-*-freebsd*
5014 Sanyo XStormy16 xstormy16-elf
5016 * OBSOLETE configurations and files
5018 Configurations that have been declared obsolete in this release have
5019 been commented out. Unless there is activity to revive these
5020 configurations, the next release of GDB will have their sources
5021 permanently REMOVED.
5023 AMD 29k family via UDI a29k-amd-udi, udi29k
5024 A29K VxWorks a29k-*-vxworks
5025 AMD 29000 embedded, using EBMON a29k-none-none
5026 AMD 29000 embedded with COFF a29k-none-coff
5027 AMD 29000 embedded with a.out a29k-none-aout
5029 testsuite/gdb.hp/gdb.threads-hp/ directory
5031 * REMOVED configurations and files
5033 TI TMS320C80 tic80-*-*
5035 PowerPC Solaris powerpcle-*-solaris*
5036 PowerPC Windows NT powerpcle-*-cygwin32
5037 PowerPC Netware powerpc-*-netware*
5038 Harris/CXUX m88k m88*-harris-cxux*
5039 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5040 ns32k-utek-sysv* ns32k-utek-*
5041 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5042 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5043 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5044 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5045 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5047 * Changes to command line processing
5049 The new `--args' feature can be used to specify command-line arguments
5050 for the inferior from gdb's command line.
5052 * Changes to key bindings
5054 There is a new `operate-and-get-next' function bound to `C-o'.
5056 *** Changes in GDB 5.1.1
5058 Fix compile problem on DJGPP.
5060 Fix a problem with floating-point registers on the i386 being
5063 Fix to stop GDB crashing on .debug_str debug info.
5065 Numerous documentation fixes.
5067 Numerous testsuite fixes.
5069 *** Changes in GDB 5.1:
5071 * New native configurations
5073 Alpha FreeBSD alpha*-*-freebsd*
5074 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5075 MIPS GNU/Linux mips*-*-linux*
5076 MIPS SGI Irix 6.x mips*-sgi-irix6*
5077 ia64 AIX ia64-*-aix*
5078 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5082 Motorola 68HC11 and 68HC12 m68hc11-elf
5084 UltraSparc running GNU/Linux sparc64-*-linux*
5086 * OBSOLETE configurations and files
5088 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5089 Harris/CXUX m88k m88*-harris-cxux*
5090 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5091 ns32k-utek-sysv* ns32k-utek-*
5092 TI TMS320C80 tic80-*-*
5094 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5095 PowerPC Solaris powerpcle-*-solaris*
5096 PowerPC Windows NT powerpcle-*-cygwin32
5097 PowerPC Netware powerpc-*-netware*
5098 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5099 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5100 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5101 Apple Macintosh (MPW) host N/A
5103 stuff.c (Program to stuff files into a specially prepared space in kdb)
5104 kdb-start.c (Main loop for the standalone kernel debugger)
5106 Configurations that have been declared obsolete in this release have
5107 been commented out. Unless there is activity to revive these
5108 configurations, the next release of GDB will have their sources
5109 permanently REMOVED.
5111 * REMOVED configurations and files
5113 Altos 3068 m68*-altos-*
5114 Convex c1-*-*, c2-*-*
5116 ARM RISCix arm-*-* (as host)
5120 * GDB has been converted to ISO C.
5122 GDB's source code has been converted to ISO C. In particular, the
5123 sources are fully protoized, and rely on standard headers being
5128 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5130 * The MI enabled by default.
5132 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5133 revised and enabled by default. Packages which use GDB as a debugging
5134 engine behind a UI or another front end are encouraged to switch to
5135 using the GDB/MI interface, instead of the old annotations interface
5136 which is now deprecated.
5138 * Support for debugging Pascal programs.
5140 GDB now includes support for debugging Pascal programs. The following
5141 main features are supported:
5143 - Pascal-specific data types such as sets;
5145 - automatic recognition of Pascal sources based on file-name
5148 - Pascal-style display of data types, variables, and functions;
5150 - a Pascal expression parser.
5152 However, some important features are not yet supported.
5154 - Pascal string operations are not supported at all;
5156 - there are some problems with boolean types;
5158 - Pascal type hexadecimal constants are not supported
5159 because they conflict with the internal variables format;
5161 - support for Pascal objects and classes is not full yet;
5163 - unlike Pascal, GDB is case-sensitive for symbol names.
5165 * Changes in completion.
5167 Commands such as `shell', `run' and `set args', which pass arguments
5168 to inferior programs, now complete on file names, similar to what
5169 users expect at the shell prompt.
5171 Commands which accept locations, such as `disassemble', `print',
5172 `breakpoint', `until', etc. now complete on filenames as well as
5173 program symbols. Thus, if you type "break foob TAB", and the source
5174 files linked into the programs include `foobar.c', that file name will
5175 be one of the candidates for completion. However, file names are not
5176 considered for completion after you typed a colon that delimits a file
5177 name from a name of a function in that file, as in "break foo.c:bar".
5179 `set demangle-style' completes on available demangling styles.
5181 * New platform-independent commands:
5183 It is now possible to define a post-hook for a command as well as a
5184 hook that runs before the command. For more details, see the
5185 documentation of `hookpost' in the GDB manual.
5187 * Changes in GNU/Linux native debugging.
5189 Support for debugging multi-threaded programs has been completely
5190 revised for all platforms except m68k and sparc. You can now debug as
5191 many threads as your system allows you to have.
5193 Attach/detach is supported for multi-threaded programs.
5195 Support for SSE registers was added for x86. This doesn't work for
5196 multi-threaded programs though.
5198 * Changes in MIPS configurations.
5200 Multi-arch support is enabled for all MIPS configurations.
5202 GDB can now be built as native debugger on SGI Irix 6.x systems for
5203 debugging n32 executables. (Debugging 64-bit executables is not yet
5206 * Unified support for hardware watchpoints in all x86 configurations.
5208 Most (if not all) native x86 configurations support hardware-assisted
5209 breakpoints and watchpoints in a unified manner. This support
5210 implements debug register sharing between watchpoints, which allows to
5211 put a virtually infinite number of watchpoints on the same address,
5212 and also supports watching regions up to 16 bytes with several debug
5215 The new maintenance command `maintenance show-debug-regs' toggles
5216 debugging print-outs in functions that insert, remove, and test
5217 watchpoints and hardware breakpoints.
5219 * Changes in the DJGPP native configuration.
5221 New command ``info dos sysinfo'' displays assorted information about
5222 the CPU, OS, memory, and DPMI server.
5224 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5225 display information about segment descriptors stored in GDT, LDT, and
5228 New commands ``info dos pde'' and ``info dos pte'' display entries
5229 from Page Directory and Page Tables (for now works with CWSDPMI only).
5230 New command ``info dos address-pte'' displays the Page Table entry for
5231 a given linear address.
5233 GDB can now pass command lines longer than 126 characters to the
5234 program being debugged (requires an update to the libdbg.a library
5235 which is part of the DJGPP development kit).
5237 DWARF2 debug info is now supported.
5239 It is now possible to `step' and `next' through calls to `longjmp'.
5241 * Changes in documentation.
5243 All GDB documentation was converted to GFDL, the GNU Free
5244 Documentation License.
5246 Tracepoints-related commands are now fully documented in the GDB
5249 TUI, the Text-mode User Interface, is now documented in the manual.
5251 Tracepoints-related commands are now fully documented in the GDB
5254 The "GDB Internals" manual now has an index. It also includes
5255 documentation of `ui_out' functions, GDB coding standards, x86
5256 hardware watchpoints, and memory region attributes.
5258 * GDB's version number moved to ``version.in''
5260 The Makefile variable VERSION has been replaced by the file
5261 ``version.in''. People creating GDB distributions should update the
5262 contents of this file.
5266 GUD support is now a standard part of the EMACS distribution.
5268 *** Changes in GDB 5.0:
5270 * Improved support for debugging FP programs on x86 targets
5272 Unified and much-improved support for debugging floating-point
5273 programs on all x86 targets. In particular, ``info float'' now
5274 displays the FP registers in the same format on all x86 targets, with
5275 greater level of detail.
5277 * Improvements and bugfixes in hardware-assisted watchpoints
5279 It is now possible to watch array elements, struct members, and
5280 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5281 on x86 targets no longer erroneously trigger when the address is
5284 * Improvements in the native DJGPP version of GDB
5286 The distribution now includes all the scripts and auxiliary files
5287 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5288 machines ``out of the box''.
5290 The DJGPP version can now debug programs that use signals. It is
5291 possible to catch signals that happened in the debuggee, deliver
5292 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5293 would kill the program being debugged.) Programs that hook hardware
5294 interrupts (keyboard, timer, etc.) can also be debugged.
5296 It is now possible to debug DJGPP programs that redirect their
5297 standard handles or switch them to raw (as opposed to cooked) mode, or
5298 even close them. The command ``run < foo > bar'' works as expected,
5299 and ``info terminal'' reports useful information about the debuggee's
5300 terminal, including raw/cooked mode, redirection, etc.
5302 The DJGPP version now uses termios functions for console I/O, which
5303 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5306 DOS-style file names with drive letters are now fully supported by
5309 It is now possible to debug DJGPP programs that switch their working
5310 directory. It is also possible to rerun the debuggee any number of
5311 times without restarting GDB; thus, you can use the same setup,
5312 breakpoints, etc. for many debugging sessions.
5314 * New native configurations
5316 ARM GNU/Linux arm*-*-linux*
5317 PowerPC GNU/Linux powerpc-*-linux*
5321 Motorola MCore mcore-*-*
5322 x86 VxWorks i[3456]86-*-vxworks*
5323 PowerPC VxWorks powerpc-*-vxworks*
5324 TI TMS320C80 tic80-*-*
5326 * OBSOLETE configurations
5328 Altos 3068 m68*-altos-*
5329 Convex c1-*-*, c2-*-*
5331 ARM RISCix arm-*-* (as host)
5334 Configurations that have been declared obsolete will be commented out,
5335 but the code will be left in place. If there is no activity to revive
5336 these configurations before the next release of GDB, the sources will
5337 be permanently REMOVED.
5339 * Gould support removed
5341 Support for the Gould PowerNode and NP1 has been removed.
5343 * New features for SVR4
5345 On SVR4 native platforms (such as Solaris), if you attach to a process
5346 without first loading a symbol file, GDB will now attempt to locate and
5347 load symbols from the running process's executable file.
5349 * Many C++ enhancements
5351 C++ support has been greatly improved. Overload resolution now works properly
5352 in almost all cases. RTTI support is on the way.
5354 * Remote targets can connect to a sub-program
5356 A popen(3) style serial-device has been added. This device starts a
5357 sub-process (such as a stand-alone simulator) and then communicates
5358 with that. The sub-program to run is specified using the syntax
5359 ``|<program> <args>'' vis:
5361 (gdb) set remotedebug 1
5362 (gdb) target extended-remote |mn10300-elf-sim program-args
5364 * MIPS 64 remote protocol
5366 A long standing bug in the mips64 remote protocol where by GDB
5367 expected certain 32 bit registers (ex SR) to be transfered as 32
5368 instead of 64 bits has been fixed.
5370 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5371 added to provide backward compatibility with older versions of GDB.
5373 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5375 The command ``set remotebinarydownload'' command has been replaced by
5376 ``set remote X-packet''. Other commands in ``set remote'' family
5377 include ``set remote P-packet''.
5379 * Breakpoint commands accept ranges.
5381 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5382 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5383 ``tracepoint passcount'' also accepts a range of tracepoints.
5385 * ``apropos'' command added.
5387 The ``apropos'' command searches through command names and
5388 documentation strings, printing out matches, making it much easier to
5389 try to find a command that does what you are looking for.
5393 A new machine oriented interface (MI) has been added to GDB. This
5394 interface is designed for debug environments running GDB as a separate
5395 process. This is part of the long term libGDB project. See the
5396 "GDB/MI" chapter of the GDB manual for further information. It can be
5397 enabled by configuring with:
5399 .../configure --enable-gdbmi
5401 *** Changes in GDB-4.18:
5403 * New native configurations
5405 HP-UX 10.20 hppa*-*-hpux10.20
5406 HP-UX 11.x hppa*-*-hpux11.0*
5407 M68K GNU/Linux m68*-*-linux*
5411 Fujitsu FR30 fr30-*-elf*
5412 Intel StrongARM strongarm-*-*
5413 Mitsubishi D30V d30v-*-*
5415 * OBSOLETE configurations
5417 Gould PowerNode, NP1 np1-*-*, pn-*-*
5419 Configurations that have been declared obsolete will be commented out,
5420 but the code will be left in place. If there is no activity to revive
5421 these configurations before the next release of GDB, the sources will
5422 be permanently REMOVED.
5426 As a compatibility experiment, GDB's source files buildsym.h and
5427 buildsym.c have been converted to pure standard C, no longer
5428 containing any K&R compatibility code. We believe that all systems in
5429 use today either come with a standard C compiler, or have a GCC port
5430 available. If this is not true, please report the affected
5431 configuration to bug-gdb@gnu.org immediately. See the README file for
5432 information about getting a standard C compiler if you don't have one
5437 GDB now uses readline 2.2.
5439 * set extension-language
5441 You can now control the mapping between filename extensions and source
5442 languages by using the `set extension-language' command. For instance,
5443 you can ask GDB to treat .c files as C++ by saying
5444 set extension-language .c c++
5445 The command `info extensions' lists all of the recognized extensions
5446 and their associated languages.
5448 * Setting processor type for PowerPC and RS/6000
5450 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5451 you can use the `set processor' command to specify what variant of the
5452 PowerPC family you are debugging. The command
5456 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5457 following PowerPC and RS6000 variants:
5459 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5460 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5462 403GC IBM PowerPC 403GC
5463 505 Motorola PowerPC 505
5464 860 Motorola PowerPC 860 or 850
5465 601 Motorola PowerPC 601
5466 602 Motorola PowerPC 602
5467 603 Motorola/IBM PowerPC 603 or 603e
5468 604 Motorola PowerPC 604 or 604e
5469 750 Motorola/IBM PowerPC 750 or 750
5471 At the moment, this command just tells GDB what to name the
5472 special-purpose processor registers. Since almost all the affected
5473 registers are inaccessible to user-level programs, this command is
5474 only useful for remote debugging in its present form.
5478 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5479 more extensive support for HP-UX. Added features include shared
5480 library support, kernel threads and hardware watchpoints for 11.00,
5481 support for HP's ANSI C and C++ compilers, and a compatibility mode
5482 for xdb and dbx commands.
5486 HP's donation includes the new concept of catchpoints, which is a
5487 generalization of the old catch command. On HP-UX, it is now possible
5488 to catch exec, fork, and vfork, as well as library loading.
5490 This means that the existing catch command has changed; its first
5491 argument now specifies the type of catch to be set up. See the
5492 output of "help catch" for a list of catchpoint types.
5494 * Debugging across forks
5496 On HP-UX, you can choose which process to debug when a fork() happens
5501 HP has donated a curses-based terminal user interface (TUI). To get
5502 it, build with --enable-tui. Although this can be enabled for any
5503 configuration, at present it only works for native HP debugging.
5505 * GDB remote protocol additions
5507 A new protocol packet 'X' that writes binary data is now available.
5508 Default behavior is to try 'X', then drop back to 'M' if the stub
5509 fails to respond. The settable variable `remotebinarydownload'
5510 allows explicit control over the use of 'X'.
5512 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5513 full 64-bit address. The command
5515 set remoteaddresssize 32
5517 can be used to revert to the old behaviour. For existing remote stubs
5518 the change should not be noticed, as the additional address information
5521 In order to assist in debugging stubs, you may use the maintenance
5522 command `packet' to send any text string to the stub. For instance,
5524 maint packet heythere
5526 sends the packet "$heythere#<checksum>". Note that it is very easy to
5527 disrupt a debugging session by sending the wrong packet at the wrong
5530 The compare-sections command allows you to compare section data on the
5531 target to what is in the executable file without uploading or
5532 downloading, by comparing CRC checksums.
5534 * Tracing can collect general expressions
5536 You may now collect general expressions at tracepoints. This requires
5537 further additions to the target-side stub; see tracepoint.c and
5538 doc/agentexpr.texi for further details.
5540 * mask-address variable for Mips
5542 For Mips targets, you may control the zeroing of the upper 32 bits of
5543 a 64-bit address by entering `set mask-address on'. This is mainly
5544 of interest to users of embedded R4xxx and R5xxx processors.
5546 * Higher serial baud rates
5548 GDB's serial code now allows you to specify baud rates 57600, 115200,
5549 230400, and 460800 baud. (Note that your host system may not be able
5550 to achieve all of these rates.)
5554 The i960 configuration now includes an initial implementation of a
5555 builtin simulator, contributed by Jim Wilson.
5558 *** Changes in GDB-4.17:
5560 * New native configurations
5562 Alpha GNU/Linux alpha*-*-linux*
5563 Unixware 2.x i[3456]86-unixware2*
5564 Irix 6.x mips*-sgi-irix6*
5565 PowerPC GNU/Linux powerpc-*-linux*
5566 PowerPC Solaris powerpcle-*-solaris*
5567 Sparc GNU/Linux sparc-*-linux*
5568 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5572 Argonaut Risc Chip (ARC) arc-*-*
5573 Hitachi H8/300S h8300*-*-*
5574 Matsushita MN10200 w/simulator mn10200-*-*
5575 Matsushita MN10300 w/simulator mn10300-*-*
5576 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5577 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5578 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5579 Mitsubishi D10V w/simulator d10v-*-*
5580 Mitsubishi M32R/D w/simulator m32r-*-elf*
5581 Tsqware Sparclet sparclet-*-*
5582 NEC V850 w/simulator v850-*-*
5584 * New debugging protocols
5586 ARM with RDI protocol arm*-*-*
5587 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5588 DDB and LSI variants of PMON protocol mips*-*-*
5589 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5590 PowerPC with SDS protocol powerpc{,le}-*-eabi
5591 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5595 All configurations can now understand and use the DWARF 2 debugging
5596 format. The choice is automatic, if the symbol file contains DWARF 2
5601 GDB now includes basic Java language support. This support is
5602 only useful with Java compilers that produce native machine code.
5604 * solib-absolute-prefix and solib-search-path
5606 For SunOS and SVR4 shared libraries, you may now set the prefix for
5607 loading absolute shared library symbol files, and the search path for
5608 locating non-absolute shared library symbol files.
5610 * Live range splitting
5612 GDB can now effectively debug code for which GCC has performed live
5613 range splitting as part of its optimization. See gdb/doc/LRS for
5614 more details on the expected format of the stabs information.
5618 GDB's support for the GNU Hurd, including thread debugging, has been
5619 updated to work with current versions of the Hurd.
5623 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5624 instruction set. ARM GDB automatically detects when Thumb
5625 instructions are in use, and adjusts disassembly and backtracing
5630 GDB's MIPS target configurations now handle the MIP16 16-bit
5635 GDB now includes support for overlays; if an executable has been
5636 linked such that multiple sections are based at the same address, GDB
5637 will decide which section to use for symbolic info. You can choose to
5638 control the decision manually, using overlay commands, or implement
5639 additional target-side support and use "overlay load-target" to bring
5640 in the overlay mapping. Do "help overlay" for more detail.
5644 The command "info symbol <address>" displays information about
5645 the symbol at the specified address.
5649 The standard remote protocol now includes an extension that allows
5650 asynchronous collection and display of trace data. This requires
5651 extensive support in the target-side debugging stub. Tracing mode
5652 includes a new interaction mode in GDB and new commands: see the
5653 file tracepoint.c for more details.
5657 Configurations for embedded MIPS now include a simulator contributed
5658 by Cygnus Solutions. The simulator supports the instruction sets
5659 of most MIPS variants.
5663 Sparc configurations may now include the ERC32 simulator contributed
5664 by the European Space Agency. The simulator is not built into
5665 Sparc targets by default; configure with --enable-sim to include it.
5669 For target configurations that may include multiple variants of a
5670 basic architecture (such as MIPS and SH), you may now set the
5671 architecture explicitly. "set arch" sets, "info arch" lists
5672 the possible architectures.
5674 *** Changes in GDB-4.16:
5676 * New native configurations
5678 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5679 M68K NetBSD m68k-*-netbsd*
5680 PowerPC AIX 4.x powerpc-*-aix*
5681 PowerPC MacOS powerpc-*-macos*
5682 PowerPC Windows NT powerpcle-*-cygwin32
5683 RS/6000 AIX 4.x rs6000-*-aix4*
5687 ARM with RDP protocol arm-*-*
5688 I960 with MON960 i960-*-coff
5689 MIPS VxWorks mips*-*-vxworks*
5690 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5691 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5693 Matra Sparclet sparclet-*-*
5697 The powerpc-eabi configuration now includes the PSIM simulator,
5698 contributed by Andrew Cagney, with assistance from Mike Meissner.
5699 PSIM is a very elaborate model of the PowerPC, including not only
5700 basic instruction set execution, but also details of execution unit
5701 performance and I/O hardware. See sim/ppc/README for more details.
5705 GDB now works with Solaris 2.5.
5707 * Windows 95/NT native
5709 GDB will now work as a native debugger on Windows 95 and Windows NT.
5710 To build it from source, you must use the "gnu-win32" environment,
5711 which uses a DLL to emulate enough of Unix to run the GNU tools.
5712 Further information, binaries, and sources are available at
5713 ftp.cygnus.com, under pub/gnu-win32.
5715 * dont-repeat command
5717 If a user-defined command includes the command `dont-repeat', then the
5718 command will not be repeated if the user just types return. This is
5719 useful if the command is time-consuming to run, so that accidental
5720 extra keystrokes don't run the same command many times.
5722 * Send break instead of ^C
5724 The standard remote protocol now includes an option to send a break
5725 rather than a ^C to the target in order to interrupt it. By default,
5726 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5728 * Remote protocol timeout
5730 The standard remote protocol includes a new variable `remotetimeout'
5731 that allows you to set the number of seconds before GDB gives up trying
5732 to read from the target. The default value is 2.
5734 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5736 By default GDB will automatically keep track of objects as they are
5737 loaded and unloaded by the dynamic linker. By using the command `set
5738 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5739 when shared library events occur, thus allowing you to set breakpoints
5740 in shared libraries which are explicitly loaded by the inferior.
5742 Note this feature does not work on hpux8. On hpux9 you must link
5743 /usr/lib/end.o into your program. This feature should work
5744 automatically on hpux10.
5746 * Irix 5.x hardware watchpoint support
5748 Irix 5 configurations now support the use of hardware watchpoints.
5750 * Mips protocol "SYN garbage limit"
5752 When debugging a Mips target using the `target mips' protocol, you
5753 may set the number of characters that GDB will ignore by setting
5754 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5755 every character. The default value is 1050.
5757 * Recording and replaying remote debug sessions
5759 If you set `remotelogfile' to the name of a file, gdb will write to it
5760 a recording of a remote debug session. This recording may then be
5761 replayed back to gdb using "gdbreplay". See gdbserver/README for
5762 details. This is useful when you have a problem with GDB while doing
5763 remote debugging; you can make a recording of the session and send it
5764 to someone else, who can then recreate the problem.
5766 * Speedups for remote debugging
5768 GDB includes speedups for downloading and stepping MIPS systems using
5769 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5770 and more efficient S-record downloading.
5772 * Memory use reductions and statistics collection
5774 GDB now uses less memory and reports statistics about memory usage.
5775 Try the `maint print statistics' command, for example.
5777 *** Changes in GDB-4.15:
5779 * Psymtabs for XCOFF
5781 The symbol reader for AIX GDB now uses partial symbol tables. This
5782 can greatly improve startup time, especially for large executables.
5784 * Remote targets use caching
5786 Remote targets now use a data cache to speed up communication with the
5787 remote side. The data cache could lead to incorrect results because
5788 it doesn't know about volatile variables, thus making it impossible to
5789 debug targets which use memory mapped I/O devices. `set remotecache
5790 off' turns the the data cache off.
5792 * Remote targets may have threads
5794 The standard remote protocol now includes support for multiple threads
5795 in the target system, using new protocol commands 'H' and 'T'. See
5796 gdb/remote.c for details.
5800 If GDB is configured with `--enable-netrom', then it will include
5801 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5802 acts as though it is a bank of ROM on the target board, but you can
5803 write into it over the network. GDB's support consists only of
5804 support for fast loading into the emulated ROM; to debug, you must use
5805 another protocol, such as standard remote protocol. The usual
5806 sequence is something like
5808 target nrom <netrom-hostname>
5810 target remote <netrom-hostname>:1235
5814 GDB now includes support for the Apple Macintosh, as a host only. It
5815 may be run as either an MPW tool or as a standalone application, and
5816 it can debug through the serial port. All the usual GDB commands are
5817 available, but to the target command, you must supply "serial" as the
5818 device type instead of "/dev/ttyXX". See mpw-README in the main
5819 directory for more information on how to build. The MPW configuration
5820 scripts */mpw-config.in support only a few targets, and only the
5821 mips-idt-ecoff target has been tested.
5825 GDB configuration now uses autoconf. This is not user-visible,
5826 but does simplify configuration and building.
5830 GDB now supports hpux10.
5832 *** Changes in GDB-4.14:
5834 * New native configurations
5836 x86 FreeBSD i[345]86-*-freebsd
5837 x86 NetBSD i[345]86-*-netbsd
5838 NS32k NetBSD ns32k-*-netbsd
5839 Sparc NetBSD sparc-*-netbsd
5843 A29K VxWorks a29k-*-vxworks
5844 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5845 CPU32 EST-300 emulator m68*-*-est*
5846 PowerPC ELF powerpc-*-elf
5849 * Alpha OSF/1 support for procfs
5851 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5852 possible to attach to running processes. As the mounting of the /proc
5853 filesystem is optional on the Alpha, GDB automatically determines
5854 the availability of /proc during startup. This can lead to problems
5855 if /proc is unmounted after GDB has been started.
5857 * Arguments to user-defined commands
5859 User commands may accept up to 10 arguments separated by whitespace.
5860 Arguments are accessed within the user command via $arg0..$arg9. A
5863 print $arg0 + $arg1 + $arg2
5865 To execute the command use:
5868 Defines the command "adder" which prints the sum of its three arguments.
5869 Note the arguments are text substitutions, so they may reference variables,
5870 use complex expressions, or even perform inferior function calls.
5872 * New `if' and `while' commands
5874 This makes it possible to write more sophisticated user-defined
5875 commands. Both commands take a single argument, which is the
5876 expression to evaluate, and must be followed by the commands to
5877 execute, one per line, if the expression is nonzero, the list being
5878 terminated by the word `end'. The `if' command list may include an
5879 `else' word, which causes the following commands to be executed only
5880 if the expression is zero.
5882 * Fortran source language mode
5884 GDB now includes partial support for Fortran 77. It will recognize
5885 Fortran programs and can evaluate a subset of Fortran expressions, but
5886 variables and functions may not be handled correctly. GDB will work
5887 with G77, but does not yet know much about symbols emitted by other
5890 * Better HPUX support
5892 Most debugging facilities now work on dynamic executables for HPPAs
5893 running hpux9 or later. You can attach to running dynamically linked
5894 processes, but by default the dynamic libraries will be read-only, so
5895 for instance you won't be able to put breakpoints in them. To change
5896 that behavior do the following before running the program:
5902 This will cause the libraries to be mapped private and read-write.
5903 To revert to the normal behavior, do this:
5909 You cannot set breakpoints or examine data in the library until after
5910 the library is loaded if the function/data symbols do not have
5913 GDB can now also read debug symbols produced by the HP C compiler on
5914 HPPAs (sorry, no C++, Fortran or 68k support).
5916 * Target byte order now dynamically selectable
5918 You can choose which byte order to use with a target system, via the
5919 commands "set endian big" and "set endian little", and you can see the
5920 current setting by using "show endian". You can also give the command
5921 "set endian auto", in which case GDB will use the byte order
5922 associated with the executable. Currently, only embedded MIPS
5923 configurations support dynamic selection of target byte order.
5925 * New DOS host serial code
5927 This version uses DPMI interrupts to handle buffered I/O, so you
5928 no longer need to run asynctsr when debugging boards connected to
5931 *** Changes in GDB-4.13:
5933 * New "complete" command
5935 This lists all the possible completions for the rest of the line, if it
5936 were to be given as a command itself. This is intended for use by emacs.
5938 * Trailing space optional in prompt
5940 "set prompt" no longer adds a space for you after the prompt you set. This
5941 allows you to set a prompt which ends in a space or one that does not.
5943 * Breakpoint hit counts
5945 "info break" now displays a count of the number of times the breakpoint
5946 has been hit. This is especially useful in conjunction with "ignore"; you
5947 can ignore a large number of breakpoint hits, look at the breakpoint info
5948 to see how many times the breakpoint was hit, then run again, ignoring one
5949 less than that number, and this will get you quickly to the last hit of
5952 * Ability to stop printing at NULL character
5954 "set print null-stop" will cause GDB to stop printing the characters of
5955 an array when the first NULL is encountered. This is useful when large
5956 arrays actually contain only short strings.
5958 * Shared library breakpoints
5960 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5961 breakpoints in shared libraries before the executable is run.
5963 * Hardware watchpoints
5965 There is a new hardware breakpoint for the watch command for sparclite
5966 targets. See gdb/sparclite/hw_breakpoint.note.
5968 Hardware watchpoints are also now supported under GNU/Linux.
5972 Annotations have been added. These are for use with graphical interfaces,
5973 and are still experimental. Currently only gdba.el uses these.
5975 * Improved Irix 5 support
5977 GDB now works properly with Irix 5.2.
5979 * Improved HPPA support
5981 GDB now works properly with the latest GCC and GAS.
5983 * New native configurations
5985 Sequent PTX4 i[34]86-sequent-ptx4
5986 HPPA running OSF/1 hppa*-*-osf*
5987 Atari TT running SVR4 m68*-*-sysv4*
5988 RS/6000 LynxOS rs6000-*-lynxos*
5992 OS/9000 i[34]86-*-os9k
5993 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5996 * Hitachi SH7000 and E7000-PC ICE support
5998 There is now support for communicating with the Hitachi E7000-PC ICE.
5999 This is available automatically when GDB is configured for the SH.
6003 As usual, a variety of small fixes and improvements, both generic
6004 and configuration-specific. See the ChangeLog for more detail.
6006 *** Changes in GDB-4.12:
6008 * Irix 5 is now supported
6012 GDB-4.12 on the HPPA has a number of changes which make it unable
6013 to debug the output from the currently released versions of GCC and
6014 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6015 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6016 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6019 *** Changes in GDB-4.11:
6021 * User visible changes:
6025 The "set remotedebug" option is now consistent between the mips remote
6026 target, remote targets using the gdb-specific protocol, UDI (AMD's
6027 debug protocol for the 29k) and the 88k bug monitor. It is now an
6028 integer specifying a debug level (normally 0 or 1, but 2 means more
6029 debugging info for the mips target).
6031 * DEC Alpha native support
6033 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6034 debug info, but GDB works fairly well with the DEC compiler and should
6035 work with a future GCC release. See the README file for a few
6036 Alpha-specific notes.
6038 * Preliminary thread implementation
6040 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6042 * LynxOS native and target support for 386
6044 This release has been hosted on LynxOS 2.2, and also can be configured
6045 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6048 * Improvements in C++ mangling/demangling.
6050 This release has much better g++ debugging, specifically in name
6051 mangling/demangling, virtual function calls, print virtual table,
6052 call methods, ...etc.
6054 *** Changes in GDB-4.10:
6056 * User visible changes:
6058 Remote debugging using the GDB-specific (`target remote') protocol now
6059 supports the `load' command. This is only useful if you have some
6060 other way of getting the stub to the target system, and you can put it
6061 somewhere in memory where it won't get clobbered by the download.
6063 Filename completion now works.
6065 When run under emacs mode, the "info line" command now causes the
6066 arrow to point to the line specified. Also, "info line" prints
6067 addresses in symbolic form (as well as hex).
6069 All vxworks based targets now support a user settable option, called
6070 vxworks-timeout. This option represents the number of seconds gdb
6071 should wait for responses to rpc's. You might want to use this if
6072 your vxworks target is, perhaps, a slow software simulator or happens
6073 to be on the far side of a thin network line.
6077 This release contains support for using a DEC alpha as a GDB host for
6078 cross debugging. Native alpha debugging is not supported yet.
6081 *** Changes in GDB-4.9:
6085 This is the first GDB release which is accompanied by a matching testsuite.
6086 The testsuite requires installation of dejagnu, which should be available
6087 via ftp from most sites that carry GNU software.
6091 'Cfront' style demangling has had its name changed to 'ARM' style, to
6092 emphasize that it was written from the specifications in the C++ Annotated
6093 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6094 disclaimers, it still generated too much confusion with users attempting to
6095 use gdb with AT&T cfront.
6099 GDB now uses a standard remote interface to a simulator library.
6100 So far, the library contains simulators for the Zilog Z8001/2, the
6101 Hitachi H8/300, H8/500 and Super-H.
6103 * New targets supported
6105 H8/300 simulator h8300-hitachi-hms or h8300hms
6106 H8/500 simulator h8500-hitachi-hms or h8500hms
6107 SH simulator sh-hitachi-hms or sh
6108 Z8000 simulator z8k-zilog-none or z8ksim
6109 IDT MIPS board over serial line mips-idt-ecoff
6111 Cross-debugging to GO32 targets is supported. It requires a custom
6112 version of the i386-stub.c module which is integrated with the
6113 GO32 memory extender.
6115 * New remote protocols
6117 MIPS remote debugging protocol.
6119 * New source languages supported
6121 This version includes preliminary support for Chill, a Pascal like language
6122 used by telecommunications companies. Chill support is also being integrated
6123 into the GNU compiler, but we don't know when it will be publically available.
6126 *** Changes in GDB-4.8:
6128 * HP Precision Architecture supported
6130 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6131 version of this support was available as a set of patches from the
6132 University of Utah. GDB does not support debugging of programs
6133 compiled with the HP compiler, because HP will not document their file
6134 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6135 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6137 Many problems in the preliminary version have been fixed.
6139 * Faster and better demangling
6141 We have improved template demangling and fixed numerous bugs in the GNU style
6142 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6143 character types (wchar_t) are now supported. Demangling of each symbol is now
6144 only done once, and is cached when the symbol table for a file is read in.
6145 This results in a small increase in memory usage for C programs, a moderate
6146 increase in memory usage for C++ programs, and a fantastic speedup in
6149 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6150 from the specifications in the Annotated Reference Manual, which AT&T's
6151 compiler does not actually implement.
6153 * G++ multiple inheritance compiler problem
6155 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6156 inheritance lattices was reworked to properly discover ambiguities. We
6157 recently found an example which causes this new algorithm to fail in a
6158 very subtle way, producing bad debug information for those classes.
6159 The file 'gcc.patch' (in this directory) can be applied to gcc to
6160 circumvent the problem. A future GCC release will contain a complete
6163 The previous G++ debug info problem (mentioned below for the gdb-4.7
6164 release) is fixed in gcc version 2.3.2.
6166 * Improved configure script
6168 The `configure' script will now attempt to guess your system type if
6169 you don't supply a host system type. The old scheme of supplying a
6170 host system triplet is preferable over using this. All the magic is
6171 done in the new `config.guess' script. Examine it for details.
6173 We have also brought our configure script much more in line with the FSF's
6174 version. It now supports the --with-xxx options. In particular,
6175 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6176 The resulting GDB will not be able to read arbitrary object file formats --
6177 only the format ``expected'' to be used on the configured target system.
6178 We hope to make this the default in a future release.
6180 * Documentation improvements
6182 There's new internal documentation on how to modify GDB, and how to
6183 produce clean changes to the code. We implore people to read it
6184 before submitting changes.
6186 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6187 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6188 `info' files are also provided. To build `info' files from scratch,
6189 you will need the latest `makeinfo' release, which will be available in
6190 a future texinfo-X.Y release.
6192 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6193 We're not sure exactly which versions have this problem, but it has
6194 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6195 or better. If that isn't possible, there is a patch in
6196 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6197 around this problem.
6201 GDB now supports array constants that can be used in expressions typed in by
6202 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6203 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6206 The new directory `gdb/sparclite' contains a program that demonstrates
6207 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6209 * New native hosts supported
6211 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6212 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6214 * New targets supported
6216 AMD 29k family via UDI a29k-amd-udi or udi29k
6218 * New file formats supported
6220 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6221 HPUX core files, and SCO 3.2v2 core files.
6225 Attaching to processes now works again; thanks for the many bug reports.
6227 We have also stomped on a bunch of core dumps caused by
6228 printf_filtered("%s") problems.
6230 We eliminated a copyright problem on the rpc and ptrace header files
6231 for VxWorks, which was discovered at the last minute during the 4.7
6232 release. You should now be able to build a VxWorks GDB.
6234 You can now interrupt gdb while an attached process is running. This
6235 will cause the attached process to stop, and give control back to GDB.
6237 We fixed problems caused by using too many file descriptors
6238 for reading symbols from object files and libraries. This was
6239 especially a problem for programs that used many (~100) shared
6242 The `step' command now only enters a subroutine if there is line number
6243 information for the subroutine. Otherwise it acts like the `next'
6244 command. Previously, `step' would enter subroutines if there was
6245 any debugging information about the routine. This avoids problems
6246 when using `cc -g1' on MIPS machines.
6248 * Internal improvements
6250 GDB's internal interfaces have been improved to make it easier to support
6251 debugging of multiple languages in the future.
6253 GDB now uses a common structure for symbol information internally.
6254 Minimal symbols (derived from linkage symbols in object files), partial
6255 symbols (from a quick scan of debug information), and full symbols
6256 contain a common subset of information, making it easier to write
6257 shared code that handles any of them.
6259 * New command line options
6261 We now accept --silent as an alias for --quiet.
6265 The memory-mapped-malloc library is now licensed under the GNU Library
6266 General Public License.
6268 *** Changes in GDB-4.7:
6270 * Host/native/target split
6272 GDB has had some major internal surgery to untangle the support for
6273 hosts and remote targets. Now, when you configure GDB for a remote
6274 target, it will no longer load in all of the support for debugging
6275 local programs on the host. When fully completed and tested, this will
6276 ensure that arbitrary host/target combinations are possible.
6278 The primary conceptual shift is to separate the non-portable code in
6279 GDB into three categories. Host specific code is required any time GDB
6280 is compiled on that host, regardless of the target. Target specific
6281 code relates to the peculiarities of the target, but can be compiled on
6282 any host. Native specific code is everything else: it can only be
6283 built when the host and target are the same system. Child process
6284 handling and core file support are two common `native' examples.
6286 GDB's use of /proc for controlling Unix child processes is now cleaner.
6287 It has been split out into a single module under the `target_ops' vector,
6288 plus two native-dependent functions for each system that uses /proc.
6290 * New hosts supported
6292 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6293 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6294 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6296 * New targets supported
6298 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6299 68030 and CPU32 m68030-*-*, m68332-*-*
6301 * New native hosts supported
6303 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6304 (386bsd is not well tested yet)
6305 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6307 * New file formats supported
6309 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6310 supports reading of `a.out.adobe' object files, which are an a.out
6311 format extended with minimal information about multiple sections.
6315 `show copying' is the same as the old `info copying'.
6316 `show warranty' is the same as `info warrantee'.
6317 These were renamed for consistency. The old commands continue to work.
6319 `info handle' is a new alias for `info signals'.
6321 You can now define pre-command hooks, which attach arbitrary command
6322 scripts to any command. The commands in the hook will be executed
6323 prior to the user's command. You can also create a hook which will be
6324 executed whenever the program stops. See gdb.texinfo.
6328 We now deal with Cfront style name mangling, and can even extract type
6329 info from mangled symbols. GDB can automatically figure out which
6330 symbol mangling style your C++ compiler uses.
6332 Calling of methods and virtual functions has been improved as well.
6336 The crash that occured when debugging Sun Ansi-C compiled binaries is
6337 fixed. This was due to mishandling of the extra N_SO stabs output
6340 We also finally got Ultrix 4.2 running in house, and fixed core file
6341 support, with help from a dozen people on the net.
6343 John M. Farrell discovered that the reason that single-stepping was so
6344 slow on all of the Mips based platforms (primarily SGI and DEC) was
6345 that we were trying to demangle and lookup a symbol used for internal
6346 purposes on every instruction that was being stepped through. Changing
6347 the name of that symbol so that it couldn't be mistaken for a C++
6348 mangled symbol sped things up a great deal.
6350 Rich Pixley sped up symbol lookups in general by getting much smarter
6351 about when C++ symbol mangling is necessary. This should make symbol
6352 completion (TAB on the command line) much faster. It's not as fast as
6353 we'd like, but it's significantly faster than gdb-4.6.
6357 A new user controllable variable 'call_scratch_address' can
6358 specify the location of a scratch area to be used when GDB
6359 calls a function in the target. This is necessary because the
6360 usual method of putting the scratch area on the stack does not work
6361 in systems that have separate instruction and data spaces.
6363 We integrated changes to support the 29k UDI (Universal Debugger
6364 Interface), but discovered at the last minute that we didn't have all
6365 of the appropriate copyright paperwork. We are working with AMD to
6366 resolve this, and hope to have it available soon.
6370 We have sped up the remote serial line protocol, especially for targets
6371 with lots of registers. It now supports a new `expedited status' ('T')
6372 message which can be used in place of the existing 'S' status message.
6373 This allows the remote stub to send only the registers that GDB
6374 needs to make a quick decision about single-stepping or conditional
6375 breakpoints, eliminating the need to fetch the entire register set for
6376 each instruction being stepped through.
6378 The GDB remote serial protocol now implements a write-through cache for
6379 registers, only re-reading the registers if the target has run.
6381 There is also a new remote serial stub for SPARC processors. You can
6382 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6383 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6384 processor with a serial port.
6388 Configure.in files have become much easier to read and modify. A new
6389 `table driven' format makes it more obvious what configurations are
6390 supported, and what files each one uses.
6394 There is a new opcodes library which will eventually contain all of the
6395 disassembly routines and opcode tables. At present, it only contains
6396 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6397 disassembler (binutils/objdump) to share these routines.
6399 The libiberty library is now copylefted under the GNU Library General
6400 Public License. This allows more liberal use, and was done so libg++
6401 can use it. This makes no difference to GDB, since the Library License
6402 grants all the rights from the General Public License.
6406 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6407 reference to the stabs symbol info used by the debugger. It is (as far
6408 as we know) the only published document on this fascinating topic. We
6409 encourage you to read it, compare it to the stabs information on your
6410 system, and send improvements on the document in general (to
6411 bug-gdb@prep.ai.mit.edu).
6413 And, of course, many bugs have been fixed.
6416 *** Changes in GDB-4.6:
6418 * Better support for C++ function names
6420 GDB now accepts as input the "demangled form" of C++ overloaded function
6421 names and member function names, and can do command completion on such names
6422 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6423 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6424 Make use of command completion, it is your friend.
6426 GDB also now accepts a variety of C++ mangled symbol formats. They are
6427 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6428 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6429 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6430 for the list of formats.
6432 * G++ symbol mangling problem
6434 Recent versions of gcc have a bug in how they emit debugging information for
6435 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6436 directory) can be applied to gcc to fix the problem. Alternatively, if you
6437 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6438 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6439 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6442 * New 'maintenance' command
6444 All of the commands related to hacking GDB internals have been moved out of
6445 the main command set, and now live behind the 'maintenance' command. This
6446 can also be abbreviated as 'mt'. The following changes were made:
6448 dump-me -> maintenance dump-me
6449 info all-breakpoints -> maintenance info breakpoints
6450 printmsyms -> maintenance print msyms
6451 printobjfiles -> maintenance print objfiles
6452 printpsyms -> maintenance print psymbols
6453 printsyms -> maintenance print symbols
6455 The following commands are new:
6457 maintenance demangle Call internal GDB demangler routine to
6458 demangle a C++ link name and prints the result.
6459 maintenance print type Print a type chain for a given symbol
6461 * Change to .gdbinit file processing
6463 We now read the $HOME/.gdbinit file before processing the argv arguments
6464 (e.g. reading symbol files or core files). This allows global parameters to
6465 be set, which will apply during the symbol reading. The ./.gdbinit is still
6466 read after argv processing.
6468 * New hosts supported
6470 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6472 GNU/Linux support i386-unknown-linux or linux
6474 We are also including code to support the HP/PA running BSD and HPUX. This
6475 is almost guaranteed not to work, as we didn't have time to test or build it
6476 for this release. We are including it so that the more adventurous (or
6477 masochistic) of you can play with it. We also had major problems with the
6478 fact that the compiler that we got from HP doesn't support the -g option.
6481 * New targets supported
6483 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6485 * More smarts about finding #include files
6487 GDB now remembers the compilation directory for all include files, and for
6488 all files from which C is generated (like yacc and lex sources). This
6489 greatly improves GDB's ability to find yacc/lex sources, and include files,
6490 especially if you are debugging your program from a directory different from
6491 the one that contains your sources.
6493 We also fixed a bug which caused difficulty with listing and setting
6494 breakpoints in include files which contain C code. (In the past, you had to
6495 try twice in order to list an include file that you hadn't looked at before.)
6497 * Interesting infernals change
6499 GDB now deals with arbitrary numbers of sections, where the symbols for each
6500 section must be relocated relative to that section's landing place in the
6501 target's address space. This work was needed to support ELF with embedded
6502 stabs used by Solaris-2.0.
6504 * Bug fixes (of course!)
6506 There have been loads of fixes for the following things:
6507 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6508 i960, stabs, DOS(GO32), procfs, etc...
6510 See the ChangeLog for details.
6512 *** Changes in GDB-4.5:
6514 * New machines supported (host and target)
6516 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6518 SGI Irix-4.x mips-sgi-irix4 or iris4
6520 * New malloc package
6522 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6523 Mmalloc is capable of handling mutiple heaps of memory. It is also
6524 capable of saving a heap to a file, and then mapping it back in later.
6525 This can be used to greatly speedup the startup of GDB by using a
6526 pre-parsed symbol table which lives in a mmalloc managed heap. For
6527 more details, please read mmalloc/mmalloc.texi.
6531 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6532 'help info proc' for details.
6534 * MIPS ecoff symbol table format
6536 The code that reads MIPS symbol table format is now supported on all hosts.
6537 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6540 * File name changes for MS-DOS
6542 Many files in the config directories have been renamed to make it easier to
6543 support GDB on MS-DOSe systems (which have very restrictive file name
6544 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6545 environment) is close to working but has some remaining problems. Note
6546 that debugging of DOS programs is not supported, due to limitations
6547 in the ``operating system'', but it can be used to host cross-debugging.
6549 * Cross byte order fixes
6551 Many fixes have been made to support cross debugging of Sparc and MIPS
6552 targets from hosts whose byte order differs.
6554 * New -mapped and -readnow options
6556 If memory-mapped files are available on your system through the 'mmap'
6557 system call, you can use the -mapped option on the `file' or
6558 `symbol-file' commands to cause GDB to write the symbols from your
6559 program into a reusable file. If the program you are debugging is
6560 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6561 Future GDB debugging sessions will notice the presence of this file,
6562 and will quickly map in symbol information from it, rather than reading
6563 the symbol table from the executable program. Using the '-mapped'
6564 option in a GDB `file' or `symbol-file' command has the same effect as
6565 starting GDB with the '-mapped' command-line option.
6567 You can cause GDB to read the entire symbol table immediately by using
6568 the '-readnow' option with any of the commands that load symbol table
6569 information (or on the GDB command line). This makes the command
6570 slower, but makes future operations faster.
6572 The -mapped and -readnow options are typically combined in order to
6573 build a `fred.syms' file that contains complete symbol information.
6574 A simple GDB invocation to do nothing but build a `.syms' file for future
6577 gdb -batch -nx -mapped -readnow programname
6579 The `.syms' file is specific to the host machine on which GDB is run.
6580 It holds an exact image of GDB's internal symbol table. It cannot be
6581 shared across multiple host platforms.
6583 * longjmp() handling
6585 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6586 siglongjmp() without losing control. This feature has not yet been ported to
6587 all systems. It currently works on many 386 platforms, all MIPS-based
6588 platforms (SGI, DECstation, etc), and Sun3/4.
6592 Preliminary work has been put in to support the new Solaris OS from Sun. At
6593 this time, it can control and debug processes, but it is not capable of
6598 As always, many many bug fixes. The major areas were with g++, and mipsread.
6599 People using the MIPS-based platforms should experience fewer mysterious
6600 crashes and trashed symbol tables.
6602 *** Changes in GDB-4.4:
6604 * New machines supported (host and target)
6606 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6608 BSD Reno on Vax vax-dec-bsd
6609 Ultrix on Vax vax-dec-ultrix
6611 * New machines supported (target)
6613 AMD 29000 embedded, using EBMON a29k-none-none
6617 GDB continues to improve its handling of C++. `References' work better.
6618 The demangler has also been improved, and now deals with symbols mangled as
6619 per the Annotated C++ Reference Guide.
6621 GDB also now handles `stabs' symbol information embedded in MIPS
6622 `ecoff' symbol tables. Since the ecoff format was not easily
6623 extensible to handle new languages such as C++, this appeared to be a
6624 good way to put C++ debugging info into MIPS binaries. This option
6625 will be supported in the GNU C compiler, version 2, when it is
6628 * New features for SVR4
6630 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6631 shared libraries. Debugging dynamically linked programs should present
6632 only minor differences from debugging statically linked programs.
6634 The `info proc' command will print out information about any process
6635 on an SVR4 system (including the one you are debugging). At the moment,
6636 it prints the address mappings of the process.
6638 If you bring up GDB on another SVR4 system, please send mail to
6639 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6641 * Better dynamic linking support in SunOS
6643 Reading symbols from shared libraries which contain debugging symbols
6644 now works properly. However, there remain issues such as automatic
6645 skipping of `transfer vector' code during function calls, which
6646 make it harder to debug code in a shared library, than to debug the
6647 same code linked statically.
6651 GDB is now using the latest `getopt' routines from the FSF. This
6652 version accepts the -- prefix for options with long names. GDB will
6653 continue to accept the old forms (-option and +option) as well.
6654 Various single letter abbreviations for options have been explicity
6655 added to the option table so that they won't get overshadowed in the
6656 future by other options that begin with the same letter.
6660 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6661 Many assorted bugs have been handled. Many more remain to be handled.
6662 See the various ChangeLog files (primarily in gdb and bfd) for details.
6665 *** Changes in GDB-4.3:
6667 * New machines supported (host and target)
6669 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6670 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6671 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6673 * Almost SCO Unix support
6675 We had hoped to support:
6676 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6677 (except for core file support), but we discovered very late in the release
6678 that it has problems with process groups that render gdb unusable. Sorry
6679 about that. I encourage people to fix it and post the fixes.
6681 * Preliminary ELF and DWARF support
6683 GDB can read ELF object files on System V Release 4, and can handle
6684 debugging records for C, in DWARF format, in ELF files. This support
6685 is preliminary. If you bring up GDB on another SVR4 system, please
6686 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6691 GDB now uses the latest `readline' library. One user-visible change
6692 is that two tabs will list possible command completions, which previously
6693 required typing M-? (meta-question mark, or ESC ?).
6697 The `stepi' bug that many of you noticed has been squashed.
6698 Many bugs in C++ have been handled. Many more remain to be handled.
6699 See the various ChangeLog files (primarily in gdb and bfd) for details.
6701 * State of the MIPS world (in case you wondered):
6703 GDB can understand the symbol tables emitted by the compilers
6704 supplied by most vendors of MIPS-based machines, including DEC. These
6705 symbol tables are in a format that essentially nobody else uses.
6707 Some versions of gcc come with an assembler post-processor called
6708 mips-tfile. This program is required if you want to do source-level
6709 debugging of gcc-compiled programs. I believe FSF does not ship
6710 mips-tfile with gcc version 1, but it will eventually come with gcc
6713 Debugging of g++ output remains a problem. g++ version 1.xx does not
6714 really support it at all. (If you're lucky, you should be able to get
6715 line numbers and stack traces to work, but no parameters or local
6716 variables.) With some work it should be possible to improve the
6719 When gcc version 2 is released, you will have somewhat better luck.
6720 However, even then you will get confusing results for inheritance and
6723 We will eventually provide full debugging of g++ output on
6724 DECstations. This will probably involve some kind of stabs-in-ecoff
6725 encapulation, but the details have not been worked out yet.
6728 *** Changes in GDB-4.2:
6730 * Improved configuration
6732 Only one copy of `configure' exists now, and it is not self-modifying.
6733 Porting BFD is simpler.
6737 The `step' and `next' commands now only stop at the first instruction
6738 of a source line. This prevents the multiple stops that used to occur
6739 in switch statements, for-loops, etc. `Step' continues to stop if a
6740 function that has debugging information is called within the line.
6744 Lots of small bugs fixed. More remain.
6746 * New host supported (not target)
6748 Intel 386 PC clone running Mach i386-none-mach
6751 *** Changes in GDB-4.1:
6753 * Multiple source language support
6755 GDB now has internal scaffolding to handle several source languages.
6756 It determines the type of each source file from its filename extension,
6757 and will switch expression parsing and number formatting to match the
6758 language of the function in the currently selected stack frame.
6759 You can also specifically set the language to be used, with
6760 `set language c' or `set language modula-2'.
6764 GDB now has preliminary support for the GNU Modula-2 compiler,
6765 currently under development at the State University of New York at
6766 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6767 continue through the fall of 1991 and into 1992.
6769 Other Modula-2 compilers are currently not supported, and attempting to
6770 debug programs compiled with them will likely result in an error as the
6771 symbol table is read. Feel free to work on it, though!
6773 There are hooks in GDB for strict type checking and range checking,
6774 in the `Modula-2 philosophy', but they do not currently work.
6778 GDB can now write to executable and core files (e.g. patch
6779 a variable's value). You must turn this switch on, specify
6780 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6781 by assigning a new value to a variable. Modifications take
6784 * Automatic SunOS shared library reading
6786 When you run your program, GDB automatically determines where its
6787 shared libraries (if any) have been loaded, and reads their symbols.
6788 The `share' command is no longer needed. This also works when
6789 examining core files.
6793 You can specify the number of lines that the `list' command shows.
6796 * New machines supported (host and target)
6798 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6799 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6800 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6802 * New hosts supported (not targets)
6804 IBM RT/PC: romp-ibm-aix or rtpc
6806 * New targets supported (not hosts)
6808 AMD 29000 embedded with COFF a29k-none-coff
6809 AMD 29000 embedded with a.out a29k-none-aout
6810 Ultracomputer remote kernel debug a29k-nyu-kern
6812 * New remote interfaces
6818 *** Changes in GDB-4.0:
6822 Wide output is wrapped at good places to make the output more readable.
6824 Gdb now supports cross-debugging from a host machine of one type to a
6825 target machine of another type. Communication with the target system
6826 is over serial lines. The ``target'' command handles connecting to the
6827 remote system; the ``load'' command will download a program into the
6828 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6829 also supports debugging of realtime processes running under VxWorks,
6830 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6831 stub on the target system.
6833 New CPUs supported include the AMD 29000 and Intel 960.
6835 GDB now reads object files and symbol tables via a ``binary file''
6836 library, which allows a single copy of GDB to debug programs of multiple
6837 object file types such as a.out and coff.
6839 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6840 refcard.dvi and refcard.ps are available to format it).
6843 * Control-Variable user interface simplified
6845 All variables that control the operation of the debugger can be set
6846 by the ``set'' command, and displayed by the ``show'' command.
6848 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6849 ``Show prompt'' produces the response:
6850 Gdb's prompt is new-gdb=>.
6852 What follows are the NEW set commands. The command ``help set'' will
6853 print a complete list of old and new set commands. ``help set FOO''
6854 will give a longer description of the variable FOO. ``show'' will show
6855 all of the variable descriptions and their current settings.
6857 confirm on/off: Enables warning questions for operations that are
6858 hard to recover from, e.g. rerunning the program while
6859 it is already running. Default is ON.
6861 editing on/off: Enables EMACS style command line editing
6862 of input. Previous lines can be recalled with
6863 control-P, the current line can be edited with control-B,
6864 you can search for commands with control-R, etc.
6867 history filename NAME: NAME is where the gdb command history
6868 will be stored. The default is .gdb_history,
6869 or the value of the environment variable
6872 history size N: The size, in commands, of the command history. The
6873 default is 256, or the value of the environment variable
6876 history save on/off: If this value is set to ON, the history file will
6877 be saved after exiting gdb. If set to OFF, the
6878 file will not be saved. The default is OFF.
6880 history expansion on/off: If this value is set to ON, then csh-like
6881 history expansion will be performed on
6882 command line input. The default is OFF.
6884 radix N: Sets the default radix for input and output. It can be set
6885 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6886 in the current radix, so "set radix 10" is always a no-op.
6888 height N: This integer value is the number of lines on a page. Default
6889 is 24, the current `stty rows'' setting, or the ``li#''
6890 setting from the termcap entry matching the environment
6893 width N: This integer value is the number of characters on a line.
6894 Default is 80, the current `stty cols'' setting, or the ``co#''
6895 setting from the termcap entry matching the environment
6898 Note: ``set screensize'' is obsolete. Use ``set height'' and
6899 ``set width'' instead.
6901 print address on/off: Print memory addresses in various command displays,
6902 such as stack traces and structure values. Gdb looks
6903 more ``symbolic'' if you turn this off; it looks more
6904 ``machine level'' with it on. Default is ON.
6906 print array on/off: Prettyprint arrays. New convenient format! Default
6909 print demangle on/off: Print C++ symbols in "source" form if on,
6912 print asm-demangle on/off: Same, for assembler level printouts
6915 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6918 * Support for Epoch Environment.
6920 The epoch environment is a version of Emacs v18 with windowing. One
6921 new command, ``inspect'', is identical to ``print'', except that if you
6922 are running in the epoch environment, the value is printed in its own
6926 * Support for Shared Libraries
6928 GDB can now debug programs and core files that use SunOS shared libraries.
6929 Symbols from a shared library cannot be referenced
6930 before the shared library has been linked with the program (this
6931 happens after you type ``run'' and before the function main() is entered).
6932 At any time after this linking (including when examining core files
6933 from dynamically linked programs), gdb reads the symbols from each
6934 shared library when you type the ``sharedlibrary'' command.
6935 It can be abbreviated ``share''.
6937 sharedlibrary REGEXP: Load shared object library symbols for files
6938 matching a unix regular expression. No argument
6939 indicates to load symbols for all shared libraries.
6941 info sharedlibrary: Status of loaded shared libraries.
6946 A watchpoint stops execution of a program whenever the value of an
6947 expression changes. Checking for this slows down execution
6948 tremendously whenever you are in the scope of the expression, but is
6949 quite useful for catching tough ``bit-spreader'' or pointer misuse
6950 problems. Some machines such as the 386 have hardware for doing this
6951 more quickly, and future versions of gdb will use this hardware.
6953 watch EXP: Set a watchpoint (breakpoint) for an expression.
6955 info watchpoints: Information about your watchpoints.
6957 delete N: Deletes watchpoint number N (same as breakpoints).
6958 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6959 enable N: Re-enables watchpoint number N (same as breakpoints).
6962 * C++ multiple inheritance
6964 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6967 * C++ exception handling
6969 Gdb now supports limited C++ exception handling. Besides the existing
6970 ability to breakpoint on an exception handler, gdb can breakpoint on
6971 the raising of an exception (before the stack is peeled back to the
6974 catch FOO: If there is a FOO exception handler in the dynamic scope,
6975 set a breakpoint to catch exceptions which may be raised there.
6976 Multiple exceptions (``catch foo bar baz'') may be caught.
6978 info catch: Lists all exceptions which may be caught in the
6979 current stack frame.
6982 * Minor command changes
6984 The command ``call func (arg, arg, ...)'' now acts like the print
6985 command, except it does not print or save a value if the function's result
6986 is void. This is similar to dbx usage.
6988 The ``up'' and ``down'' commands now always print the frame they end up
6989 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6990 frames without printing.
6992 * New directory command
6994 'dir' now adds directories to the FRONT of the source search path.
6995 The path starts off empty. Source files that contain debug information
6996 about the directory in which they were compiled can be found even
6997 with an empty path; Sun CC and GCC include this information. If GDB can't
6998 find your source file in the current directory, type "dir .".
7000 * Configuring GDB for compilation
7002 For normal use, type ``./configure host''. See README or gdb.texinfo
7005 GDB now handles cross debugging. If you are remotely debugging between
7006 two different machines, type ``./configure host -target=targ''.
7007 Host is the machine where GDB will run; targ is the machine
7008 where the program that you are debugging will run.