1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.1
6 * The commands 'info variables/functions/types' now show the source line
7 numbers of symbol definitions when available.
9 * 'info proc' now works on running processes on FreeBSD systems and core
10 files created on FreeBSD systems.
12 * C expressions can now use _Alignof, and C++ expressions can now use
19 Control display of debugging info regarding the FreeBSD native target.
21 set|show varsize-limit
22 This new setting allows the user to control the maximum size of Ada
23 objects being printed when those objects have a variable type,
24 instead of that maximum size being hardcoded to 65536 bytes.
26 set|show record btrace cpu
27 Controls the processor to be used for enabling errata workarounds for
32 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
34 ** The commands attached to a breakpoint can be set by assigning to
35 the breakpoint's "commands" field.
37 ** gdb.execute can now execute multi-line gdb commands.
41 RiscV ELF riscv*-*-elf
43 * Removed targets and native configurations
45 m88k running OpenBSD m88*-*-openbsd*
46 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
47 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
48 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
50 * Aarch64/Linux hardware watchpoints improvements
52 Hardware watchpoints on unaligned addresses are now properly
53 supported when running Linux kernel 4.10 or higher: read and access
54 watchpoints are no longer spuriously missed, and all watchpoints
55 lengths between 1 and 8 bytes are supported. On older kernels,
56 watchpoints set on unaligned addresses are no longer missed, with
57 the tradeoff that there is a possibility of false hits being
60 *** Changes in GDB 8.1
62 * GDB now supports dynamically creating arbitrary register groups specified
63 in XML target descriptions. This allows for finer grain grouping of
64 registers on systems with a large amount of registers.
66 * The 'ptype' command now accepts a '/o' flag, which prints the
67 offsets and sizes of fields in a struct, like the pahole(1) tool.
69 * New "--readnever" command line option instructs GDB to not read each
70 symbol file's symbolic debug information. This makes startup faster
71 but at the expense of not being able to perform symbolic debugging.
72 This option is intended for use cases where symbolic debugging will
73 not be used, e.g., when you only need to dump the debuggee's core.
75 * GDB now uses the GNU MPFR library, if available, to emulate target
76 floating-point arithmetic during expression evaluation when the target
77 uses different floating-point formats than the host. At least version
78 3.1 of GNU MPFR is required.
80 * GDB now supports access to the guarded-storage-control registers and the
81 software-based guarded-storage broadcast control registers on IBM z14.
83 * On Unix systems, GDB now supports transmitting environment variables
84 that are to be set or unset to GDBserver. These variables will
85 affect the environment to be passed to the remote inferior.
87 To inform GDB of environment variables that are to be transmitted to
88 GDBserver, use the "set environment" command. Only user set
89 environment variables are sent to GDBserver.
91 To inform GDB of environment variables that are to be unset before
92 the remote inferior is started by the GDBserver, use the "unset
95 * Completion improvements
97 ** GDB can now complete function parameters in linespecs and
98 explicit locations without quoting. When setting breakpoints,
99 quoting around functions names to help with TAB-completion is
100 generally no longer necessary. For example, this now completes
103 (gdb) b function(in[TAB]
104 (gdb) b function(int)
106 Related, GDB is no longer confused with completing functions in
107 C++ anonymous namespaces:
110 (gdb) b (anonymous namespace)::[TAB][TAB]
111 (anonymous namespace)::a_function()
112 (anonymous namespace)::b_function()
114 ** GDB now has much improved linespec and explicit locations TAB
115 completion support, that better understands what you're
116 completing and offers better suggestions. For example, GDB no
117 longer offers data symbols as possible completions when you're
118 setting a breakpoint.
120 ** GDB now TAB-completes label symbol names.
122 ** The "complete" command now mimics TAB completion accurately.
124 * New command line options (gcore)
127 Dump all memory mappings.
129 * Breakpoints on C++ functions are now set on all scopes by default
131 By default, breakpoints on functions/methods are now interpreted as
132 specifying all functions with the given name ignoring missing
133 leading scopes (namespaces and classes).
135 For example, assuming a C++ program with symbols named:
140 both commands "break func()" and "break B::func()" set a breakpoint
143 You can use the new flag "-qualified" to override this. This makes
144 GDB interpret the specified function name as a complete
145 fully-qualified name instead. For example, using the same C++
146 program, the "break -q B::func" command sets a breakpoint on
147 "B::func", only. A parameter has been added to the Python
148 gdb.Breakpoint constructor to achieve the same result when creating
149 a breakpoint from Python.
151 * Breakpoints on functions marked with C++ ABI tags
153 GDB can now set breakpoints on functions marked with C++ ABI tags
154 (e.g., [abi:cxx11]). See here for a description of ABI tags:
155 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
157 Functions with a C++11 abi tag are demangled/displayed like this:
159 function[abi:cxx11](int)
162 You can now set a breakpoint on such functions simply as if they had
165 (gdb) b function(int)
167 Or if you need to disambiguate between tags, like:
169 (gdb) b function[abi:other_tag](int)
171 Tab completion was adjusted accordingly as well.
175 ** New events gdb.new_inferior, gdb.inferior_deleted, and
176 gdb.new_thread are emitted. See the manual for further
177 description of these.
179 ** A new function, "gdb.rbreak" has been added to the Python API.
180 This function allows the setting of a large number of breakpoints
181 via a regex pattern in Python. See the manual for further details.
183 ** Python breakpoints can now accept explicit locations. See the
184 manual for a further description of this feature.
187 * New features in the GDB remote stub, GDBserver
189 ** GDBserver is now able to start inferior processes with a
190 specified initial working directory.
192 The user can set the desired working directory to be used from
193 GDB using the new "set cwd" command.
195 ** New "--selftest" command line option runs some GDBserver self
196 tests. These self tests are disabled in releases.
198 ** On Unix systems, GDBserver now does globbing expansion and variable
199 substitution in inferior command line arguments.
201 This is done by starting inferiors using a shell, like GDB does.
202 See "set startup-with-shell" in the user manual for how to disable
203 this from GDB when using "target extended-remote". When using
204 "target remote", you can disable the startup with shell by using the
205 new "--no-startup-with-shell" GDBserver command line option.
207 ** On Unix systems, GDBserver now supports receiving environment
208 variables that are to be set or unset from GDB. These variables
209 will affect the environment to be passed to the inferior.
211 * When catching an Ada exception raised with a message, GDB now prints
212 the message in the catchpoint hit notification. In GDB/MI mode, that
213 information is provided as an extra field named "exception-message"
214 in the *stopped notification.
216 * Trait objects can now be inspected When debugging Rust code. This
217 requires compiler support which will appear in Rust 1.24.
221 QEnvironmentHexEncoded
222 Inform GDBserver of an environment variable that is to be passed to
223 the inferior when starting it.
226 Inform GDBserver of an environment variable that is to be unset
227 before starting the remote inferior.
230 Inform GDBserver that the environment should be reset (i.e.,
231 user-set environment variables should be unset).
234 Indicates whether the inferior must be started with a shell or not.
237 Tell GDBserver that the inferior to be started should use a specific
240 * The "maintenance print c-tdesc" command now takes an optional
241 argument which is the file name of XML target description.
243 * The "maintenance selftest" command now takes an optional argument to
244 filter the tests to be run.
246 * The "enable", and "disable" commands now accept a range of
247 breakpoint locations, e.g. "enable 1.3-5".
252 Set and show the current working directory for the inferior.
255 Set and show compilation command used for compiling and injecting code
256 with the 'compile' commands.
258 set debug separate-debug-file
259 show debug separate-debug-file
260 Control the display of debug output about separate debug file search.
262 set dump-excluded-mappings
263 show dump-excluded-mappings
264 Control whether mappings marked with the VM_DONTDUMP flag should be
265 dumped when generating a core file.
268 List the registered selftests.
271 Start the debugged program stopping at the first instruction.
274 Control display of debugging messages related to OpenRISC targets.
276 set|show print type nested-type-limit
277 Set and show the limit of nesting level for nested types that the
278 type printer will show.
280 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
283 * Safer/improved support for debugging with no debug info
285 GDB no longer assumes functions with no debug information return
288 This means that GDB now refuses to call such functions unless you
289 tell it the function's type, by either casting the call to the
290 declared return type, or by casting the function to a function
291 pointer of the right type, and calling that:
293 (gdb) p getenv ("PATH")
294 'getenv' has unknown return type; cast the call to its declared return type
295 (gdb) p (char *) getenv ("PATH")
296 $1 = 0x7fffffffe "/usr/local/bin:/"...
297 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
298 $2 = 0x7fffffffe "/usr/local/bin:/"...
300 Similarly, GDB no longer assumes that global variables with no debug
301 info have type 'int', and refuses to print the variable's value
302 unless you tell it the variable's type:
305 'var' has unknown type; cast it to its declared type
309 * New native configurations
311 FreeBSD/aarch64 aarch64*-*-freebsd*
312 FreeBSD/arm arm*-*-freebsd*
316 FreeBSD/aarch64 aarch64*-*-freebsd*
317 FreeBSD/arm arm*-*-freebsd*
318 OpenRISC ELF or1k*-*-elf
320 * Removed targets and native configurations
322 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
324 *** Changes in GDB 8.0
326 * GDB now supports access to the PKU register on GNU/Linux. The register is
327 added by the Memory Protection Keys for Userspace feature which will be
328 available in future Intel CPUs.
330 * GDB now supports C++11 rvalue references.
334 ** New functions to start, stop and access a running btrace recording.
335 ** Rvalue references are now supported in gdb.Type.
337 * GDB now supports recording and replaying rdrand and rdseed Intel 64
340 * Building GDB and GDBserver now requires a C++11 compiler.
342 For example, GCC 4.8 or later.
344 It is no longer possible to build GDB or GDBserver with a C
345 compiler. The --disable-build-with-cxx configure option has been
348 * Building GDB and GDBserver now requires GNU make >= 3.81.
350 It is no longer supported to build GDB or GDBserver with another
351 implementation of the make program or an earlier version of GNU make.
353 * Native debugging on MS-Windows supports command-line redirection
355 Command-line arguments used for starting programs on MS-Windows can
356 now include redirection symbols supported by native Windows shells,
357 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
358 as "run", "start", and "set args", as well as the corresponding MI
361 * Support for thread names on MS-Windows.
363 GDB now catches and handles the special exception that programs
364 running on MS-Windows use to assign names to threads in the
367 * Support for Java programs compiled with gcj has been removed.
369 * User commands now accept an unlimited number of arguments.
370 Previously, only up to 10 was accepted.
372 * The "eval" command now expands user-defined command arguments.
374 This makes it easier to process a variable number of arguments:
379 eval "print $arg%d", $i
384 * Target descriptions can now describe registers for sparc32 and sparc64.
386 * GDB now supports DWARF version 5 (debug information format).
387 Its .debug_names index is not yet supported.
389 * New native configurations
391 FreeBSD/mips mips*-*-freebsd
395 Synopsys ARC arc*-*-elf32
396 FreeBSD/mips mips*-*-freebsd
398 * Removed targets and native configurations
400 Alpha running FreeBSD alpha*-*-freebsd*
401 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
406 Erases all the flash memory regions reported by the target.
408 maint print arc arc-instruction address
409 Print internal disassembler information about instruction at a given address.
413 set disassembler-options
414 show disassembler-options
415 Controls the passing of target specific information to the disassembler.
416 If it is necessary to specify more than one disassembler option then
417 multiple options can be placed together into a comma separated list.
418 The default value is the empty string. Currently, the only supported
419 targets are ARM, PowerPC and S/390.
424 Erases all the flash memory regions reported by the target. This is
425 equivalent to the CLI command flash-erase.
427 -file-list-shared-libraries
428 List the shared libraries in the program. This is
429 equivalent to the CLI command "info shared".
432 Catchpoints stopping the program when Ada exceptions are
433 handled. This is equivalent to the CLI command "catch handlers".
435 *** Changes in GDB 7.12
437 * GDB and GDBserver now build with a C++ compiler by default.
439 The --enable-build-with-cxx configure option is now enabled by
440 default. One must now explicitly configure with
441 --disable-build-with-cxx in order to build with a C compiler. This
442 option will be removed in a future release.
444 * GDBserver now supports recording btrace without maintaining an active
447 * GDB now supports a negative repeat count in the 'x' command to examine
448 memory backward from the given address. For example:
451 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
452 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
453 (gdb) x/-5i 0x0000000000400580
454 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
455 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
456 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
457 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
458 0x40057b <main(int, char**)+25>:
459 callq 0x400536 <Func1(int, char const*)>
461 * Fortran: Support structures with fields of dynamic types and
462 arrays of dynamic types.
464 * The symbol dumping maintenance commands have new syntax.
465 maint print symbols [-pc address] [--] [filename]
466 maint print symbols [-objfile objfile] [-source source] [--] [filename]
467 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
468 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
469 maint print msymbols [-objfile objfile] [--] [filename]
471 * GDB now supports multibit bitfields and enums in target register
474 * New Python-based convenience function $_as_string(val), which returns
475 the textual representation of a value. This function is especially
476 useful to obtain the text label of an enum value.
478 * Intel MPX bound violation handling.
480 Segmentation faults caused by a Intel MPX boundary violation
481 now display the kind of violation (upper or lower), the memory
482 address accessed and the memory bounds, along with the usual
483 signal received and code location.
487 Program received signal SIGSEGV, Segmentation fault
488 Upper bound violation while accessing address 0x7fffffffc3b3
489 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
490 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
492 * Rust language support.
493 GDB now supports debugging programs written in the Rust programming
494 language. See https://www.rust-lang.org/ for more information about
497 * Support for running interpreters on specified input/output devices
499 GDB now supports a new mechanism that allows frontends to provide
500 fully featured GDB console views, as a better alternative to
501 building such views on top of the "-interpreter-exec console"
502 command. See the new "new-ui" command below. With that command,
503 frontends can now start GDB in the traditional command-line mode
504 running in an embedded terminal emulator widget, and create a
505 separate MI interpreter running on a specified i/o device. In this
506 way, GDB handles line editing, history, tab completion, etc. in the
507 console all by itself, and the GUI uses the separate MI interpreter
508 for its own control and synchronization, invisible to the command
511 * The "catch syscall" command catches groups of related syscalls.
513 The "catch syscall" command now supports catching a group of related
514 syscalls using the 'group:' or 'g:' prefix.
519 skip -gfile file-glob-pattern
520 skip -function function
521 skip -rfunction regular-expression
522 A generalized form of the skip command, with new support for
523 glob-style file names and regular expressions for function names.
524 Additionally, a file spec and a function spec may now be combined.
526 maint info line-table REGEXP
527 Display the contents of GDB's internal line table data struture.
530 Run any GDB unit tests that were compiled in.
533 Start a new user interface instance running INTERP as interpreter,
534 using the TTY file for input/output.
538 ** gdb.Breakpoint objects have a new attribute "pending", which
539 indicates whether the breakpoint is pending.
540 ** Three new breakpoint-related events have been added:
541 gdb.breakpoint_created, gdb.breakpoint_modified, and
542 gdb.breakpoint_deleted.
545 Signal ("set") the given MS-Windows event object. This is used in
546 conjunction with the Windows JIT debugging (AeDebug) support, where
547 the OS suspends a crashing process until a debugger can attach to
548 it. Resuming the crashing process, in order to debug it, is done by
551 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
552 was added in GDBserver, including JIT compiling fast tracepoint's
553 conditional expression bytecode into native code.
555 * Support for various remote target protocols and ROM monitors has
558 target m32rsdi Remote M32R debugging over SDI
559 target mips MIPS remote debugging protocol
560 target pmon PMON ROM monitor
561 target ddb NEC's DDB variant of PMON for Vr4300
562 target rockhopper NEC RockHopper variant of PMON
563 target lsi LSI variant of PMO
565 * Support for tracepoints and fast tracepoints on powerpc-linux,
566 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
567 including JIT compiling fast tracepoint's conditional expression
568 bytecode into native code.
570 * MI async record =record-started now includes the method and format used for
571 recording. For example:
573 =record-started,thread-group="i1",method="btrace",format="bts"
575 * MI async record =thread-selected now includes the frame field. For example:
577 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
581 Andes NDS32 nds32*-*-elf
583 *** Changes in GDB 7.11
585 * GDB now supports debugging kernel-based threads on FreeBSD.
587 * Per-inferior thread numbers
589 Thread numbers are now per inferior instead of global. If you're
590 debugging multiple inferiors, GDB displays thread IDs using a
591 qualified INF_NUM.THR_NUM form. For example:
595 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
596 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
597 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
598 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
600 As consequence, thread numbers as visible in the $_thread
601 convenience variable and in Python's InferiorThread.num attribute
602 are no longer unique between inferiors.
604 GDB now maintains a second thread ID per thread, referred to as the
605 global thread ID, which is the new equivalent of thread numbers in
606 previous releases. See also $_gthread below.
608 For backwards compatibility, MI's thread IDs always refer to global
611 * Commands that accept thread IDs now accept the qualified
612 INF_NUM.THR_NUM form as well. For example:
615 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
618 * In commands that accept a list of thread IDs, you can now refer to
619 all threads of an inferior using a star wildcard. GDB accepts
620 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
621 refer to all threads of the current inferior. For example, "info
624 * You can use "info threads -gid" to display the global thread ID of
627 * The new convenience variable $_gthread holds the global number of
630 * The new convenience variable $_inferior holds the number of the
633 * GDB now displays the ID and name of the thread that hit a breakpoint
634 or received a signal, if your program is multi-threaded. For
637 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
638 Thread 1 "main" received signal SIGINT, Interrupt.
640 * Record btrace now supports non-stop mode.
642 * Support for tracepoints on aarch64-linux was added in GDBserver.
644 * The 'record instruction-history' command now indicates speculative execution
645 when using the Intel Processor Trace recording format.
647 * GDB now allows users to specify explicit locations, bypassing
648 the linespec parser. This feature is also available to GDB/MI
651 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
652 GDB now is able to debug both AArch64 applications and ARM applications
655 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
656 including JIT compiling fast tracepoint's conditional expression bytecode
659 * GDB now supports displaced stepping on AArch64 GNU/Linux.
661 * "info threads", "info inferiors", "info display", "info checkpoints"
662 and "maint info program-spaces" now list the corresponding items in
663 ascending ID order, for consistency with all other "info" commands.
665 * In Ada, the overloads selection menu has been enhanced to display the
666 parameter types and the return types for the matching overloaded subprograms.
670 maint set target-non-stop (on|off|auto)
671 maint show target-non-stop
672 Control whether GDB targets always operate in non-stop mode even if
673 "set non-stop" is "off". The default is "auto", meaning non-stop
674 mode is enabled if supported by the target.
676 maint set bfd-sharing
677 maint show bfd-sharing
678 Control the reuse of bfd objects.
682 Control display of debugging info regarding bfd caching.
686 Control display of debugging info regarding FreeBSD threads.
688 set remote multiprocess-extensions-packet
689 show remote multiprocess-extensions-packet
690 Set/show the use of the remote protocol multiprocess extensions.
692 set remote thread-events
693 show remote thread-events
694 Set/show the use of thread create/exit events.
696 set ada print-signatures on|off
697 show ada print-signatures"
698 Control whether parameter types and return types are displayed in overloads
699 selection menus. It is activaled (@code{on}) by default.
703 Controls the maximum size of memory, in bytes, that GDB will
704 allocate for value contents. Prevents incorrect programs from
705 causing GDB to allocate overly large buffers. Default is 64k.
707 * The "disassemble" command accepts a new modifier: /s.
708 It prints mixed source+disassembly like /m with two differences:
709 - disassembled instructions are now printed in program order, and
710 - and source for all relevant files is now printed.
711 The "/m" option is now considered deprecated: its "source-centric"
712 output hasn't proved useful in practice.
714 * The "record instruction-history" command accepts a new modifier: /s.
715 It behaves exactly like /m and prints mixed source+disassembly.
717 * The "set scheduler-locking" command supports a new mode "replay".
718 It behaves like "off" in record mode and like "on" in replay mode.
720 * Support for various ROM monitors has been removed:
722 target dbug dBUG ROM monitor for Motorola ColdFire
723 target picobug Motorola picobug monitor
724 target dink32 DINK32 ROM monitor for PowerPC
725 target m32r Renesas M32R/D ROM monitor
726 target mon2000 mon2000 ROM monitor
727 target ppcbug PPCBUG ROM monitor for PowerPC
729 * Support for reading/writing memory and extracting values on architectures
730 whose memory is addressable in units of any integral multiple of 8 bits.
733 Allows to break when an Ada exception is handled.
738 Indicates that an exec system call was executed.
740 exec-events feature in qSupported
741 The qSupported packet allows GDB to request support for exec
742 events using the new 'gdbfeature' exec-event, and the qSupported
743 response can contain the corresponding 'stubfeature'. Set and
744 show commands can be used to display whether these features are enabled.
747 Equivalent to interrupting with the ^C character, but works in
750 thread created stop reason (T05 create:...)
751 Indicates that the thread was just created and is stopped at entry.
753 thread exit stop reply (w exitcode;tid)
754 Indicates that the thread has terminated.
757 Enables/disables thread create and exit event reporting. For
758 example, this is used in non-stop mode when GDB stops a set of
759 threads and synchronously waits for the their corresponding stop
760 replies. Without exit events, if one of the threads exits, GDB
761 would hang forever not knowing that it should no longer expect a
762 stop for that same thread.
765 Indicates that there are no resumed threads left in the target (all
766 threads are stopped). The remote stub reports support for this stop
767 reply to GDB's qSupported query.
770 Enables/disables catching syscalls from the inferior process.
771 The remote stub reports support for this packet to GDB's qSupported query.
773 syscall_entry stop reason
774 Indicates that a syscall was just called.
776 syscall_return stop reason
777 Indicates that a syscall just returned.
779 * Extended-remote exec events
781 ** GDB now has support for exec events on extended-remote Linux targets.
782 For such targets with Linux kernels 2.5.46 and later, this enables
783 follow-exec-mode and exec catchpoints.
785 set remote exec-event-feature-packet
786 show remote exec-event-feature-packet
787 Set/show the use of the remote exec event feature.
789 * Thread names in remote protocol
791 The reply to qXfer:threads:read may now include a name attribute for each
794 * Target remote mode fork and exec events
796 ** GDB now has support for fork and exec events on target remote mode
797 Linux targets. For such targets with Linux kernels 2.5.46 and later,
798 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
799 fork and exec catchpoints.
801 * Remote syscall events
803 ** GDB now has support for catch syscall on remote Linux targets,
804 currently enabled on x86/x86_64 architectures.
806 set remote catch-syscall-packet
807 show remote catch-syscall-packet
808 Set/show the use of the remote catch syscall feature.
812 ** The -var-set-format command now accepts the zero-hexadecimal
813 format. It outputs data in hexadecimal format with zero-padding on the
818 ** gdb.InferiorThread objects have a new attribute "global_num",
819 which refers to the thread's global thread ID. The existing
820 "num" attribute now refers to the thread's per-inferior number.
821 See "Per-inferior thread numbers" above.
822 ** gdb.InferiorThread objects have a new attribute "inferior", which
823 is the Inferior object the thread belongs to.
825 *** Changes in GDB 7.10
827 * Support for process record-replay and reverse debugging on aarch64*-linux*
828 targets has been added. GDB now supports recording of A64 instruction set
829 including advance SIMD instructions.
831 * Support for Sun's version of the "stabs" debug file format has been removed.
833 * GDB now honors the content of the file /proc/PID/coredump_filter
834 (PID is the process ID) on GNU/Linux systems. This file can be used
835 to specify the types of memory mappings that will be included in a
836 corefile. For more information, please refer to the manual page of
837 "core(5)". GDB also has a new command: "set use-coredump-filter
838 on|off". It allows to set whether GDB will read the content of the
839 /proc/PID/coredump_filter file when generating a corefile.
841 * The "info os" command on GNU/Linux can now display information on
843 "info os cpus" Listing of all cpus/cores on the system
845 * GDB has two new commands: "set serial parity odd|even|none" and
846 "show serial parity". These allows to set or show parity for the
849 * The "info source" command now displays the producer string if it was
850 present in the debug info. This typically includes the compiler version
851 and may include things like its command line arguments.
853 * The "info dll", an alias of the "info sharedlibrary" command,
854 is now available on all platforms.
856 * Directory names supplied to the "set sysroot" commands may be
857 prefixed with "target:" to tell GDB to access shared libraries from
858 the target system, be it local or remote. This replaces the prefix
859 "remote:". The default sysroot has been changed from "" to
860 "target:". "remote:" is automatically converted to "target:" for
861 backward compatibility.
863 * The system root specified by "set sysroot" will be prepended to the
864 filename of the main executable (if reported to GDB as absolute by
865 the operating system) when starting processes remotely, and when
866 attaching to already-running local or remote processes.
868 * GDB now supports automatic location and retrieval of executable
869 files from remote targets. Remote debugging can now be initiated
870 using only a "target remote" or "target extended-remote" command
871 (no "set sysroot" or "file" commands are required). See "New remote
874 * The "dump" command now supports verilog hex format.
876 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
878 * On GNU/Linux, GDB and gdbserver are now able to access executable
879 and shared library files without a "set sysroot" command when
880 attaching to processes running in different mount namespaces from
881 the debugger. This makes it possible to attach to processes in
882 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
883 See "New remote packets" below.
885 * The "tui reg" command now provides completion for all of the
886 available register groups, including target specific groups.
888 * The HISTSIZE environment variable is no longer read when determining
889 the size of GDB's command history. GDB now instead reads the dedicated
890 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
891 disables truncation of command history. Non-numeric values of GDBHISTSIZE
896 ** Memory ports can now be unbuffered.
900 ** gdb.Objfile objects have a new attribute "username",
901 which is the name of the objfile as specified by the user,
902 without, for example, resolving symlinks.
903 ** You can now write frame unwinders in Python.
904 ** gdb.Type objects have a new method "optimized_out",
905 returning optimized out gdb.Value instance of this type.
906 ** gdb.Value objects have new methods "reference_value" and
907 "const_value" which return a reference to the value and a
908 "const" version of the value respectively.
912 maint print symbol-cache
913 Print the contents of the symbol cache.
915 maint print symbol-cache-statistics
916 Print statistics of symbol cache usage.
918 maint flush-symbol-cache
919 Flush the contents of the symbol cache.
923 Start branch trace recording using Branch Trace Store (BTS) format.
926 Evaluate expression by using the compiler and print result.
930 Explicit commands for enabling and disabling tui mode.
933 set mpx bound on i386 and amd64
934 Support for bound table investigation on Intel MPX enabled applications.
938 Start branch trace recording using Intel Processor Trace format.
941 Print information about branch tracing internals.
943 maint btrace packet-history
944 Print the raw branch tracing data.
946 maint btrace clear-packet-history
947 Discard the stored raw branch tracing data.
950 Discard all branch tracing data. It will be fetched and processed
951 anew by the next "record" command.
956 Renamed from "set debug dwarf2-die".
958 Renamed from "show debug dwarf2-die".
961 Renamed from "set debug dwarf2-read".
962 show debug dwarf-read
963 Renamed from "show debug dwarf2-read".
965 maint set dwarf always-disassemble
966 Renamed from "maint set dwarf2 always-disassemble".
967 maint show dwarf always-disassemble
968 Renamed from "maint show dwarf2 always-disassemble".
970 maint set dwarf max-cache-age
971 Renamed from "maint set dwarf2 max-cache-age".
972 maint show dwarf max-cache-age
973 Renamed from "maint show dwarf2 max-cache-age".
976 show debug dwarf-line
977 Control display of debugging info regarding DWARF line processing.
981 Set the maximum number of candidates to be considered during
982 completion. The default value is 200. This limit allows GDB
983 to avoid generating large completion lists, the computation of
984 which can cause the debugger to become temporarily unresponsive.
986 set history remove-duplicates
987 show history remove-duplicates
988 Control the removal of duplicate history entries.
990 maint set symbol-cache-size
991 maint show symbol-cache-size
992 Control the size of the symbol cache.
994 set|show record btrace bts buffer-size
995 Set and show the size of the ring buffer used for branch tracing in
997 The obtained size may differ from the requested size. Use "info
998 record" to see the obtained buffer size.
1000 set debug linux-namespaces
1001 show debug linux-namespaces
1002 Control display of debugging info regarding Linux namespaces.
1004 set|show record btrace pt buffer-size
1005 Set and show the size of the ring buffer used for branch tracing in
1006 Intel Processor Trace format.
1007 The obtained size may differ from the requested size. Use "info
1008 record" to see the obtained buffer size.
1010 maint set|show btrace pt skip-pad
1011 Set and show whether PAD packets are skipped when computing the
1014 * The command 'thread apply all' can now support new option '-ascending'
1015 to call its specified command for all threads in ascending order.
1017 * Python/Guile scripting
1019 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1020 special section named `.debug_gdb_scripts'.
1022 * New remote packets
1024 qXfer:btrace-conf:read
1025 Return the branch trace configuration for the current thread.
1027 Qbtrace-conf:bts:size
1028 Set the requested ring buffer size for branch tracing in BTS format.
1031 Enable Intel Procesor Trace-based branch tracing for the current
1032 process. The remote stub reports support for this packet to GDB's
1035 Qbtrace-conf:pt:size
1036 Set the requested ring buffer size for branch tracing in Intel Processor
1040 Indicates a memory breakpoint instruction was executed, irrespective
1041 of whether it was GDB that planted the breakpoint or the breakpoint
1042 is hardcoded in the program. This is required for correct non-stop
1046 Indicates the target stopped for a hardware breakpoint. This is
1047 required for correct non-stop mode operation.
1050 Return information about files on the remote system.
1052 qXfer:exec-file:read
1053 Return the full absolute name of the file that was executed to
1054 create a process running on the remote system.
1057 Select the filesystem on which vFile: operations with filename
1058 arguments will operate. This is required for GDB to be able to
1059 access files on remote targets where the remote stub does not
1060 share a common filesystem with the inferior(s).
1063 Indicates that a fork system call was executed.
1066 Indicates that a vfork system call was executed.
1068 vforkdone stop reason
1069 Indicates that a vfork child of the specified process has executed
1070 an exec or exit, allowing the vfork parent to resume execution.
1072 fork-events and vfork-events features in qSupported
1073 The qSupported packet allows GDB to request support for fork and
1074 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1075 and the qSupported response can contain the corresponding
1076 'stubfeatures'. Set and show commands can be used to display
1077 whether these features are enabled.
1079 * Extended-remote fork events
1081 ** GDB now has support for fork events on extended-remote Linux
1082 targets. For targets with Linux kernels 2.5.60 and later, this
1083 enables follow-fork-mode and detach-on-fork for both fork and
1084 vfork, as well as fork and vfork catchpoints.
1086 * The info record command now shows the recording format and the
1087 branch tracing configuration for the current thread when using
1088 the btrace record target.
1089 For the BTS format, it shows the ring buffer size.
1091 * GDB now has support for DTrace USDT (Userland Static Defined
1092 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1094 * GDB now supports access to vector registers on S/390 GNU/Linux
1097 * Removed command line options
1099 -xdb HP-UX XDB compatibility mode.
1101 * Removed targets and native configurations
1103 HP/PA running HP-UX hppa*-*-hpux*
1104 Itanium running HP-UX ia64-*-hpux*
1106 * New configure options
1109 This configure option allows the user to build GDB with support for
1110 Intel Processor Trace (default: auto). This requires libipt.
1112 --with-libipt-prefix=PATH
1113 Specify the path to the version of libipt that GDB should use.
1114 $PATH/include should contain the intel-pt.h header and
1115 $PATH/lib should contain the libipt.so library.
1117 *** Changes in GDB 7.9.1
1121 ** Xmethods can now specify a result type.
1123 *** Changes in GDB 7.9
1125 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1129 ** You can now access frame registers from Python scripts.
1130 ** New attribute 'producer' for gdb.Symtab objects.
1131 ** gdb.Objfile objects have a new attribute "progspace",
1132 which is the gdb.Progspace object of the containing program space.
1133 ** gdb.Objfile objects have a new attribute "owner".
1134 ** gdb.Objfile objects have a new attribute "build_id",
1135 which is the build ID generated when the file was built.
1136 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1137 ** A new event "gdb.clear_objfiles" has been added, triggered when
1138 selecting a new file to debug.
1139 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1140 ** New function gdb.lookup_objfile.
1142 New events which are triggered when GDB modifies the state of the
1145 ** gdb.events.inferior_call_pre: Function call is about to be made.
1146 ** gdb.events.inferior_call_post: Function call has just been made.
1147 ** gdb.events.memory_changed: A memory location has been altered.
1148 ** gdb.events.register_changed: A register has been altered.
1150 * New Python-based convenience functions:
1152 ** $_caller_is(name [, number_of_frames])
1153 ** $_caller_matches(regexp [, number_of_frames])
1154 ** $_any_caller_is(name [, number_of_frames])
1155 ** $_any_caller_matches(regexp [, number_of_frames])
1157 * GDB now supports the compilation and injection of source code into
1158 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1159 to compile the source code to object code, and if successful, inject
1160 and execute that code within the current context of the inferior.
1161 Currently the C language is supported. The commands used to
1162 interface with this new feature are:
1164 compile code [-raw|-r] [--] [source code]
1165 compile file [-raw|-r] filename
1169 demangle [-l language] [--] name
1170 Demangle "name" in the specified language, or the current language
1171 if elided. This command is renamed from the "maint demangle" command.
1172 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1173 as "maint demangler-warning".
1175 queue-signal signal-name-or-number
1176 Queue a signal to be delivered to the thread when it is resumed.
1178 add-auto-load-scripts-directory directory
1179 Add entries to the list of directories from which to load auto-loaded
1182 maint print user-registers
1183 List all currently available "user" registers.
1185 compile code [-r|-raw] [--] [source code]
1186 Compile, inject, and execute in the inferior the executable object
1187 code produced by compiling the provided source code.
1189 compile file [-r|-raw] filename
1190 Compile and inject into the inferior the executable object code
1191 produced by compiling the source code stored in the filename
1194 * On resume, GDB now always passes the signal the program had stopped
1195 for to the thread the signal was sent to, even if the user changed
1196 threads before resuming. Previously GDB would often (but not
1197 always) deliver the signal to the thread that happens to be current
1200 * Conversely, the "signal" command now consistently delivers the
1201 requested signal to the current thread. GDB now asks for
1202 confirmation if the program had stopped for a signal and the user
1203 switched threads meanwhile.
1205 * "breakpoint always-inserted" modes "off" and "auto" merged.
1207 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1208 won't remove breakpoints from the target until all threads stop,
1209 even in non-stop mode. The "auto" mode has been removed, and "off"
1210 is now the default mode.
1214 set debug symbol-lookup
1215 show debug symbol-lookup
1216 Control display of debugging info regarding symbol lookup.
1220 ** The -list-thread-groups command outputs an exit-code field for
1221 inferiors that have exited.
1225 MIPS SDE mips*-sde*-elf*
1229 Support for these obsolete configurations has been removed.
1231 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1232 SGI Irix-5.x mips-*-irix5*
1233 SGI Irix-6.x mips-*-irix6*
1234 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1235 VAX running Ultrix vax-*-ultrix*
1237 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1238 and "assf"), have been removed. Use the "sharedlibrary" command, or
1239 its alias "share", instead.
1241 *** Changes in GDB 7.8
1243 * New command line options
1246 This is an alias for the --data-directory option.
1248 * GDB supports printing and modifying of variable length automatic arrays
1249 as specified in ISO C99.
1251 * The ARM simulator now supports instruction level tracing
1252 with or without disassembly.
1256 GDB now has support for scripting using Guile. Whether this is
1257 available is determined at configure time.
1258 Guile version 2.0 or greater is required.
1259 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1261 * New commands (for set/show, see "New options" below)
1265 Invoke CODE by passing it to the Guile interpreter.
1269 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1271 info auto-load guile-scripts [regexp]
1272 Print the list of automatically loaded Guile scripts.
1274 * The source command is now capable of sourcing Guile scripts.
1275 This feature is dependent on the debugger being built with Guile support.
1279 set print symbol-loading (off|brief|full)
1280 show print symbol-loading
1281 Control whether to print informational messages when loading symbol
1282 information for a file. The default is "full", but when debugging
1283 programs with large numbers of shared libraries the amount of output
1284 becomes less useful.
1286 set guile print-stack (none|message|full)
1287 show guile print-stack
1288 Show a stack trace when an error is encountered in a Guile script.
1290 set auto-load guile-scripts (on|off)
1291 show auto-load guile-scripts
1292 Control auto-loading of Guile script files.
1294 maint ada set ignore-descriptive-types (on|off)
1295 maint ada show ignore-descriptive-types
1296 Control whether the debugger should ignore descriptive types in Ada
1297 programs. The default is not to ignore the descriptive types. See
1298 the user manual for more details on descriptive types and the intended
1299 usage of this option.
1301 set auto-connect-native-target
1303 Control whether GDB is allowed to automatically connect to the
1304 native target for the run, attach, etc. commands when not connected
1305 to any target yet. See also "target native" below.
1307 set record btrace replay-memory-access (read-only|read-write)
1308 show record btrace replay-memory-access
1309 Control what memory accesses are allowed during replay.
1311 maint set target-async (on|off)
1312 maint show target-async
1313 This controls whether GDB targets operate in synchronous or
1314 asynchronous mode. Normally the default is asynchronous, if it is
1315 available; but this can be changed to more easily debug problems
1316 occurring only in synchronous mode.
1318 set mi-async (on|off)
1320 Control whether MI asynchronous mode is preferred. This supersedes
1321 "set target-async" of previous GDB versions.
1323 * "set target-async" is deprecated as a CLI option and is now an alias
1324 for "set mi-async" (only puts MI into async mode).
1326 * Background execution commands (e.g., "c&", "s&", etc.) are now
1327 possible ``out of the box'' if the target supports them. Previously
1328 the user would need to explicitly enable the possibility with the
1329 "set target-async on" command.
1331 * New features in the GDB remote stub, GDBserver
1333 ** New option --debug-format=option1[,option2,...] allows one to add
1334 additional text to each output. At present only timestamps
1335 are supported: --debug-format=timestamps.
1336 Timestamps can also be turned on with the
1337 "monitor set debug-format timestamps" command from GDB.
1339 * The 'record instruction-history' command now starts counting instructions
1340 at one. This also affects the instruction ranges reported by the
1341 'record function-call-history' command when given the /i modifier.
1343 * The command 'record function-call-history' supports a new modifier '/c' to
1344 indent the function names based on their call stack depth.
1345 The fields for the '/i' and '/l' modifier have been reordered.
1346 The source line range is now prefixed with 'at'.
1347 The instruction range is now prefixed with 'inst'.
1348 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1349 "record instruction-history" and "list" commands.
1351 * The ranges given as arguments to the 'record function-call-history' and
1352 'record instruction-history' commands are now inclusive.
1354 * The btrace record target now supports the 'record goto' command.
1355 For locations inside the execution trace, the back trace is computed
1356 based on the information stored in the execution trace.
1358 * The btrace record target supports limited reverse execution and replay.
1359 The target does not record data and therefore does not allow reading
1360 memory or registers.
1362 * The "catch syscall" command now works on s390*-linux* targets.
1364 * The "compare-sections" command is no longer specific to target
1365 remote. It now works with all targets.
1367 * All native targets are now consistently called "native".
1368 Consequently, the "target child", "target GNU", "target djgpp",
1369 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1370 commands have been replaced with "target native". The QNX/NTO port
1371 leaves the "procfs" target in place and adds a "native" target for
1372 consistency with other ports. The impact on users should be minimal
1373 as these commands previously either throwed an error, or were
1374 no-ops. The target's name is visible in the output of the following
1375 commands: "help target", "info target", "info files", "maint print
1378 * The "target native" command now connects to the native target. This
1379 can be used to launch native programs even when "set
1380 auto-connect-native-target" is set to off.
1382 * GDB now supports access to Intel MPX registers on GNU/Linux.
1384 * Support for Intel AVX-512 registers on GNU/Linux.
1385 Support displaying and modifying Intel AVX-512 registers
1386 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1388 * New remote packets
1390 qXfer:btrace:read's annex
1391 The qXfer:btrace:read packet supports a new annex 'delta' to read
1392 branch trace incrementally.
1396 ** Valid Python operations on gdb.Value objects representing
1397 structs/classes invoke the corresponding overloaded operators if
1399 ** New `Xmethods' feature in the Python API. Xmethods are
1400 additional methods or replacements for existing methods of a C++
1401 class. This feature is useful for those cases where a method
1402 defined in C++ source code could be inlined or optimized out by
1403 the compiler, making it unavailable to GDB.
1406 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1408 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1409 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1410 its alias "share", instead.
1412 * The commands "set remotebaud" and "show remotebaud" are no longer
1413 supported. Use "set serial baud" and "show serial baud" (respectively)
1418 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1419 target-async". The latter is left as a deprecated alias of the
1420 former for backward compatibility. If the target supports it,
1421 CLI background execution commands are now always possible by
1422 default, independently of whether the frontend stated a
1423 preference for asynchronous execution with "-gdb-set mi-async".
1424 Previously "-gdb-set target-async off" affected both MI execution
1425 commands and CLI execution commands.
1427 *** Changes in GDB 7.7
1429 * Improved support for process record-replay and reverse debugging on
1430 arm*-linux* targets. Support for thumb32 and syscall instruction
1431 recording has been added.
1433 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1435 * GDB now supports Fission DWP file format version 2.
1436 http://gcc.gnu.org/wiki/DebugFission
1438 * New convenience function "$_isvoid", to check whether an expression
1439 is void. A void expression is an expression where the type of the
1440 result is "void". For example, some convenience variables may be
1441 "void" when evaluated (e.g., "$_exitcode" before the execution of
1442 the program being debugged; or an undefined convenience variable).
1443 Another example, when calling a function whose return type is
1446 * The "maintenance print objfiles" command now takes an optional regexp.
1448 * The "catch syscall" command now works on arm*-linux* targets.
1450 * GDB now consistently shows "<not saved>" when printing values of
1451 registers the debug info indicates have not been saved in the frame
1452 and there's nowhere to retrieve them from
1453 (callee-saved/call-clobbered registers):
1458 (gdb) info registers rax
1461 Before, the former would print "<optimized out>", and the latter
1462 "*value not available*".
1464 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1469 ** Frame filters and frame decorators have been added.
1470 ** Temporary breakpoints are now supported.
1471 ** Line tables representation has been added.
1472 ** New attribute 'parent_type' for gdb.Field objects.
1473 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1474 ** New attribute 'name' for gdb.Type objects.
1478 Nios II ELF nios2*-*-elf
1479 Nios II GNU/Linux nios2*-*-linux
1480 Texas Instruments MSP430 msp430*-*-elf
1482 * Removed native configurations
1484 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1485 been removed. ELF variants of these configurations are kept supported.
1487 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1488 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1489 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1490 i[34567]86-*-openbsd3.[0-3]
1491 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1492 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1493 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1497 Like "catch throw", but catches a re-thrown exception.
1498 maint check-psymtabs
1499 Renamed from old "maint check-symtabs".
1501 Perform consistency checks on symtabs.
1502 maint expand-symtabs
1503 Expand symtabs matching an optional regexp.
1506 Display the details of GDB configure-time options.
1508 maint set|show per-command
1509 maint set|show per-command space
1510 maint set|show per-command time
1511 maint set|show per-command symtab
1512 Enable display of per-command gdb resource usage.
1514 remove-symbol-file FILENAME
1515 remove-symbol-file -a ADDRESS
1516 Remove a symbol file added via add-symbol-file. The file to remove
1517 can be identified by its filename or by an address that lies within
1518 the boundaries of this symbol file in memory.
1521 info exceptions REGEXP
1522 Display the list of Ada exceptions defined in the program being
1523 debugged. If provided, only the exceptions whose names match REGEXP
1528 set debug symfile off|on
1530 Control display of debugging info regarding reading symbol files and
1531 symbol tables within those files
1533 set print raw frame-arguments
1534 show print raw frame-arguments
1535 Set/show whether to print frame arguments in raw mode,
1536 disregarding any defined pretty-printers.
1538 set remote trace-status-packet
1539 show remote trace-status-packet
1540 Set/show the use of remote protocol qTStatus packet.
1544 Control display of debugging messages related to Nios II targets.
1548 Control whether target-assisted range stepping is enabled.
1550 set startup-with-shell
1551 show startup-with-shell
1552 Specifies whether Unix child processes are started via a shell or
1557 Use the target memory cache for accesses to the code segment. This
1558 improves performance of remote debugging (particularly disassembly).
1560 * You can now use a literal value 'unlimited' for options that
1561 interpret 0 or -1 as meaning "unlimited". E.g., "set
1562 trace-buffer-size unlimited" is now an alias for "set
1563 trace-buffer-size -1" and "set height unlimited" is now an alias for
1566 * The "set debug symtab-create" debugging option of GDB has been changed to
1567 accept a verbosity level. 0 means "off", 1 provides basic debugging
1568 output, and values of 2 or greater provides more verbose output.
1570 * New command-line options
1572 Display the details of GDB configure-time options.
1574 * The command 'tsave' can now support new option '-ctf' to save trace
1575 buffer in Common Trace Format.
1577 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1580 * GDB now implements the the C++ 'typeid' operator.
1582 * The new convenience variable $_exception holds the exception being
1583 thrown or caught at an exception-related catchpoint.
1585 * The exception-related catchpoints, like "catch throw", now accept a
1586 regular expression which can be used to filter exceptions by type.
1588 * The new convenience variable $_exitsignal is automatically set to
1589 the terminating signal number when the program being debugged dies
1590 due to an uncaught signal.
1594 ** All MI commands now accept an optional "--language" option.
1595 Support for this feature can be verified by using the "-list-features"
1596 command, which should contain "language-option".
1598 ** The new command -info-gdb-mi-command allows the user to determine
1599 whether a GDB/MI command is supported or not.
1601 ** The "^error" result record returned when trying to execute an undefined
1602 GDB/MI command now provides a variable named "code" whose content is the
1603 "undefined-command" error code. Support for this feature can be verified
1604 by using the "-list-features" command, which should contain
1605 "undefined-command-error-code".
1607 ** The -trace-save MI command can optionally save trace buffer in Common
1610 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1612 ** The command -data-list-register-values now accepts an optional
1613 "--skip-unavailable" option. When used, only the available registers
1616 ** The new command -trace-frame-collected dumps collected variables,
1617 computed expressions, tvars, memory and registers in a traceframe.
1619 ** The commands -stack-list-locals, -stack-list-arguments and
1620 -stack-list-variables now accept an option "--skip-unavailable".
1621 When used, only the available locals or arguments are displayed.
1623 ** The -exec-run command now accepts an optional "--start" option.
1624 When used, the command follows the same semantics as the "start"
1625 command, stopping the program's execution at the start of its
1626 main subprogram. Support for this feature can be verified using
1627 the "-list-features" command, which should contain
1628 "exec-run-start-option".
1630 ** The new commands -catch-assert and -catch-exceptions insert
1631 catchpoints stopping the program when Ada exceptions are raised.
1633 ** The new command -info-ada-exceptions provides the equivalent of
1634 the new "info exceptions" command.
1636 * New system-wide configuration scripts
1637 A GDB installation now provides scripts suitable for use as system-wide
1638 configuration scripts for the following systems:
1642 * GDB now supports target-assigned range stepping with remote targets.
1643 This improves the performance of stepping source lines by reducing
1644 the number of control packets from/to GDB. See "New remote packets"
1647 * GDB now understands the element 'tvar' in the XML traceframe info.
1648 It has the id of the collected trace state variables.
1650 * On S/390 targets that provide the transactional-execution feature,
1651 the program interruption transaction diagnostic block (TDB) is now
1652 represented as a number of additional "registers" in GDB.
1654 * New remote packets
1658 The vCont packet supports a new 'r' action, that tells the remote
1659 stub to step through an address range itself, without GDB
1660 involvemement at each single-step.
1662 qXfer:libraries-svr4:read's annex
1663 The previously unused annex of the qXfer:libraries-svr4:read packet
1664 is now used to support passing an argument list. The remote stub
1665 reports support for this argument list to GDB's qSupported query.
1666 The defined arguments are "start" and "prev", used to reduce work
1667 necessary for library list updating, resulting in significant
1670 * New features in the GDB remote stub, GDBserver
1672 ** GDBserver now supports target-assisted range stepping. Currently
1673 enabled on x86/x86_64 GNU/Linux targets.
1675 ** GDBserver now adds element 'tvar' in the XML in the reply to
1676 'qXfer:traceframe-info:read'. It has the id of the collected
1677 trace state variables.
1679 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1682 * New 'z' formatter for printing and examining memory, this displays the
1683 value as hexadecimal zero padded on the left to the size of the type.
1685 * GDB can now use Windows x64 unwinding data.
1687 * The "set remotebaud" command has been replaced by "set serial baud".
1688 Similarly, "show remotebaud" has been replaced by "show serial baud".
1689 The "set remotebaud" and "show remotebaud" commands are still available
1690 to provide backward compatibility with older versions of GDB.
1692 *** Changes in GDB 7.6
1694 * Target record has been renamed to record-full.
1695 Record/replay is now enabled with the "record full" command.
1696 This also affects settings that are associated with full record/replay
1697 that have been moved from "set/show record" to "set/show record full":
1699 set|show record full insn-number-max
1700 set|show record full stop-at-limit
1701 set|show record full memory-query
1703 * A new record target "record-btrace" has been added. The new target
1704 uses hardware support to record the control-flow of a process. It
1705 does not support replaying the execution, but it implements the
1706 below new commands for investigating the recorded execution log.
1707 This new recording method can be enabled using:
1711 The "record-btrace" target is only available on Intel Atom processors
1712 and requires a Linux kernel 2.6.32 or later.
1714 * Two new commands have been added for record/replay to give information
1715 about the recorded execution without having to replay the execution.
1716 The commands are only supported by "record btrace".
1718 record instruction-history prints the execution history at
1719 instruction granularity
1721 record function-call-history prints the execution history at
1722 function granularity
1724 * New native configurations
1726 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1727 FreeBSD/powerpc powerpc*-*-freebsd
1728 x86_64/Cygwin x86_64-*-cygwin*
1729 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1733 ARM AArch64 aarch64*-*-elf
1734 ARM AArch64 GNU/Linux aarch64*-*-linux
1735 Lynx 178 PowerPC powerpc-*-lynx*178
1736 x86_64/Cygwin x86_64-*-cygwin*
1737 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1739 * If the configured location of system.gdbinit file (as given by the
1740 --with-system-gdbinit option at configure time) is in the
1741 data-directory (as specified by --with-gdb-datadir at configure
1742 time) or in one of its subdirectories, then GDB will look for the
1743 system-wide init file in the directory specified by the
1744 --data-directory command-line option.
1746 * New command line options:
1748 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1749 other initialization files, unlike -nx which disables all of them.
1751 * Removed command line options
1753 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1756 * The 'ptype' and 'whatis' commands now accept an argument to control
1759 * 'info proc' now works on some core files.
1763 ** Vectors can be created with gdb.Type.vector.
1765 ** Python's atexit.register now works in GDB.
1767 ** Types can be pretty-printed via a Python API.
1769 ** Python 3 is now supported (in addition to Python 2.4 or later)
1771 ** New class gdb.Architecture exposes GDB's internal representation
1772 of architecture in the Python API.
1774 ** New method Frame.architecture returns the gdb.Architecture object
1775 corresponding to the frame's architecture.
1777 * New Python-based convenience functions:
1779 ** $_memeq(buf1, buf2, length)
1780 ** $_streq(str1, str2)
1782 ** $_regex(str, regex)
1784 * The 'cd' command now defaults to using '~' (the home directory) if not
1787 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1788 default for GCC since November 2000.
1790 * The command 'forward-search' can now be abbreviated as 'fo'.
1792 * The command 'info tracepoints' can now display 'installed on target'
1793 or 'not installed on target' for each non-pending location of tracepoint.
1795 * New configure options
1797 --enable-libmcheck/--disable-libmcheck
1798 By default, development versions are built with -lmcheck on hosts
1799 that support it, in order to help track memory corruption issues.
1800 Release versions, on the other hand, are built without -lmcheck
1801 by default. The --enable-libmcheck/--disable-libmcheck configure
1802 options allow the user to override that default.
1803 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1804 This configure option allows the user to build GDB with
1805 libbabeltrace using which GDB can read Common Trace Format data.
1807 * New commands (for set/show, see "New options" below)
1810 Catch signals. This is similar to "handle", but allows commands and
1811 conditions to be attached.
1814 List the BFDs known to GDB.
1816 python-interactive [command]
1818 Start a Python interactive prompt, or evaluate the optional command
1819 and print the result of expressions.
1822 "py" is a new alias for "python".
1824 enable type-printer [name]...
1825 disable type-printer [name]...
1826 Enable or disable type printers.
1830 ** For the Renesas Super-H architecture, the "regs" command has been removed
1831 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1836 set print type methods (on|off)
1837 show print type methods
1838 Control whether method declarations are displayed by "ptype".
1839 The default is to show them.
1841 set print type typedefs (on|off)
1842 show print type typedefs
1843 Control whether typedef definitions are displayed by "ptype".
1844 The default is to show them.
1846 set filename-display basename|relative|absolute
1847 show filename-display
1848 Control the way in which filenames is displayed.
1849 The default is "relative", which preserves previous behavior.
1851 set trace-buffer-size
1852 show trace-buffer-size
1853 Request target to change the size of trace buffer.
1855 set remote trace-buffer-size-packet auto|on|off
1856 show remote trace-buffer-size-packet
1857 Control the use of the remote protocol `QTBuffer:size' packet.
1861 Control display of debugging messages related to ARM AArch64.
1864 set debug coff-pe-read
1865 show debug coff-pe-read
1866 Control display of debugging messages related to reading of COFF/PE
1871 Control display of debugging messages related to Mach-O symbols
1874 set debug notification
1875 show debug notification
1876 Control display of debugging info for async remote notification.
1880 ** Command parameter changes are now notified using new async record
1881 "=cmd-param-changed".
1882 ** Trace frame changes caused by command "tfind" are now notified using
1883 new async record "=traceframe-changed".
1884 ** The creation, deletion and modification of trace state variables
1885 are now notified using new async records "=tsv-created",
1886 "=tsv-deleted" and "=tsv-modified".
1887 ** The start and stop of process record are now notified using new
1888 async record "=record-started" and "=record-stopped".
1889 ** Memory changes are now notified using new async record
1891 ** The data-disassemble command response will include a "fullname" field
1892 containing the absolute file name when source has been requested.
1893 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1894 command, to allow pattern filling of memory areas.
1895 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1896 library load/unload events.
1897 ** The response to breakpoint commands and breakpoint async records
1898 includes an "installed" field containing a boolean state about each
1899 non-pending tracepoint location is whether installed on target or not.
1900 ** Output of the "-trace-status" command includes a "trace-file" field
1901 containing the name of the trace file being examined. This field is
1902 optional, and only present when examining a trace file.
1903 ** The "fullname" field is now always present along with the "file" field,
1904 even if the file cannot be found by GDB.
1906 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1907 You must have the LZMA library available when configuring GDB for this
1908 feature to be enabled. For more information, see:
1909 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1911 * New remote packets
1914 Set the size of trace buffer. The remote stub reports support for this
1915 packet to gdb's qSupported query.
1918 Enable Branch Trace Store (BTS)-based branch tracing for the current
1919 thread. The remote stub reports support for this packet to gdb's
1923 Disable branch tracing for the current thread. The remote stub reports
1924 support for this packet to gdb's qSupported query.
1927 Read the traced branches for the current thread. The remote stub
1928 reports support for this packet to gdb's qSupported query.
1930 *** Changes in GDB 7.5
1932 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1933 for more x32 ABI info.
1935 * GDB now supports access to MIPS DSP registers on Linux targets.
1937 * GDB now supports debugging microMIPS binaries.
1939 * The "info os" command on GNU/Linux can now display information on
1940 several new classes of objects managed by the operating system:
1941 "info os procgroups" lists process groups
1942 "info os files" lists file descriptors
1943 "info os sockets" lists internet-domain sockets
1944 "info os shm" lists shared-memory regions
1945 "info os semaphores" lists semaphores
1946 "info os msg" lists message queues
1947 "info os modules" lists loaded kernel modules
1949 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1950 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1951 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1952 options and inspect the probe arguments using the new $_probe_arg family
1953 of convenience variables. You can obtain more information about SystemTap
1954 in <http://sourceware.org/systemtap/>.
1956 * GDB now supports reversible debugging on ARM, it allows you to
1957 debug basic ARM and THUMB instructions, and provides
1958 record/replay support.
1960 * The option "symbol-reloading" has been deleted as it is no longer used.
1964 ** GDB commands implemented in Python can now be put in command class
1967 ** The "maint set python print-stack on|off" is now deleted.
1969 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1970 apply "flag enum"-style pretty-printing to any enum.
1972 ** gdb.lookup_symbol can now work when there is no current frame.
1974 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1975 the source at which the symbol was defined.
1977 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1978 method 'value'. The former indicates whether the symbol needs a
1979 frame in order to compute its value, and the latter computes the
1982 ** A new method 'referenced_value' on gdb.Value objects which can
1983 dereference pointer as well as C++ reference values.
1985 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1986 which return the global and static blocks (as gdb.Block objects),
1987 of the underlying symbol table, respectively.
1989 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1990 object associated with a PC value.
1992 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1993 of the address range occupied by code for the current source line.
1995 * Go language support.
1996 GDB now supports debugging programs written in the Go programming
1999 * GDBserver now supports stdio connections.
2000 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2002 * The binary "gdbtui" can no longer be built or installed.
2003 Use "gdb -tui" instead.
2005 * GDB will now print "flag" enums specially. A flag enum is one where
2006 all the enumerator values have no bits in common when pairwise
2007 "and"ed. When printing a value whose type is a flag enum, GDB will
2008 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2009 (gdb) print (enum E) 3
2012 * The filename part of a linespec will now match trailing components
2013 of a source file name. For example, "break gcc/expr.c:1000" will
2014 now set a breakpoint in build/gcc/expr.c, but not
2015 build/libcpp/expr.c.
2017 * The "info proc" and "generate-core-file" commands will now also
2018 work on remote targets connected to GDBserver on Linux.
2020 * The command "info catch" has been removed. It has been disabled
2021 since December 2007.
2023 * The "catch exception" and "catch assert" commands now accept
2024 a condition at the end of the command, much like the "break"
2025 command does. For instance:
2027 (gdb) catch exception Constraint_Error if Barrier = True
2029 Previously, it was possible to add a condition to such catchpoints,
2030 but it had to be done as a second step, after the catchpoint had been
2031 created, using the "condition" command.
2033 * The "info static-tracepoint-marker" command will now also work on
2034 native Linux targets with in-process agent.
2036 * GDB can now set breakpoints on inlined functions.
2038 * The .gdb_index section has been updated to include symbols for
2039 inlined functions. GDB will ignore older .gdb_index sections by
2040 default, which could cause symbol files to be loaded more slowly
2041 until their .gdb_index sections can be recreated. The new command
2042 "set use-deprecated-index-sections on" will cause GDB to use any older
2043 .gdb_index sections it finds. This will restore performance, but the
2044 ability to set breakpoints on inlined functions will be lost in symbol
2045 files with older .gdb_index sections.
2047 The .gdb_index section has also been updated to record more information
2048 about each symbol. This speeds up the "info variables", "info functions"
2049 and "info types" commands when used with programs having the .gdb_index
2050 section, as well as speeding up debugging with shared libraries using
2051 the .gdb_index section.
2053 * Ada support for GDB/MI Variable Objects has been added.
2055 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2060 ** New command -info-os is the MI equivalent of "info os".
2062 ** Output logs ("set logging" and related) now include MI output.
2066 ** "set use-deprecated-index-sections on|off"
2067 "show use-deprecated-index-sections on|off"
2068 Controls the use of deprecated .gdb_index sections.
2070 ** "catch load" and "catch unload" can be used to stop when a shared
2071 library is loaded or unloaded, respectively.
2073 ** "enable count" can be used to auto-disable a breakpoint after
2076 ** "info vtbl" can be used to show the virtual method tables for
2077 C++ and Java objects.
2079 ** "explore" and its sub commands "explore value" and "explore type"
2080 can be used to recursively explore values and types of
2081 expressions. These commands are available only if GDB is
2082 configured with '--with-python'.
2084 ** "info auto-load" shows status of all kinds of auto-loaded files,
2085 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2086 sequences of commands files, "info auto-load python-scripts"
2087 shows status of auto-loading Python script files,
2088 "info auto-load local-gdbinit" shows status of loading init file
2089 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2090 status of inferior specific thread debugging shared library loading.
2092 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2093 and "show auto-load-scripts" commands have been deprecated, use their
2094 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2095 and "show auto-load python-scripts" counterparts instead.
2097 ** "dprintf location,format,args..." creates a dynamic printf, which
2098 is basically a breakpoint that does a printf and immediately
2099 resumes your program's execution, so it is like a printf that you
2100 can insert dynamically at runtime instead of at compiletime.
2102 ** "set print symbol"
2104 Controls whether GDB attempts to display the symbol, if any,
2105 corresponding to addresses it prints. This defaults to "on", but
2106 you can set it to "off" to restore GDB's previous behavior.
2108 * Deprecated commands
2110 ** For the Renesas Super-H architecture, the "regs" command has been
2111 deprecated, and "info all-registers" should be used instead.
2115 Renesas RL78 rl78-*-elf
2116 HP OpenVMS ia64 ia64-hp-openvms*
2118 * GDBserver supports evaluation of breakpoint conditions. When
2119 support is advertised by GDBserver, GDB may be told to send the
2120 breakpoint conditions in bytecode form to GDBserver. GDBserver
2121 will only report the breakpoint trigger to GDB when its condition
2126 set mips compression
2127 show mips compression
2128 Select the compressed ISA encoding used in functions that have no symbol
2129 information available. The encoding can be set to either of:
2132 and is updated automatically from ELF file flags if available.
2134 set breakpoint condition-evaluation
2135 show breakpoint condition-evaluation
2136 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2137 GDBserver ("target"). Default option "auto" chooses the most efficient
2139 This option can improve debugger efficiency depending on the speed of the
2143 Disable auto-loading globally.
2146 Show auto-loading setting of all kinds of auto-loaded files.
2148 set auto-load gdb-scripts on|off
2149 show auto-load gdb-scripts
2150 Control auto-loading of GDB canned sequences of commands files.
2152 set auto-load python-scripts on|off
2153 show auto-load python-scripts
2154 Control auto-loading of Python script files.
2156 set auto-load local-gdbinit on|off
2157 show auto-load local-gdbinit
2158 Control loading of init file (.gdbinit) from current directory.
2160 set auto-load libthread-db on|off
2161 show auto-load libthread-db
2162 Control auto-loading of inferior specific thread debugging shared library.
2164 set auto-load scripts-directory <dir1>[:<dir2>...]
2165 show auto-load scripts-directory
2166 Set a list of directories from which to load auto-loaded scripts.
2167 Automatically loaded Python scripts and GDB scripts are located in one
2168 of the directories listed by this option.
2169 The delimiter (':' above) may differ according to the host platform.
2171 set auto-load safe-path <dir1>[:<dir2>...]
2172 show auto-load safe-path
2173 Set a list of directories from which it is safe to auto-load files.
2174 The delimiter (':' above) may differ according to the host platform.
2176 set debug auto-load on|off
2177 show debug auto-load
2178 Control display of debugging info for auto-loading the files above.
2180 set dprintf-style gdb|call|agent
2182 Control the way in which a dynamic printf is performed; "gdb"
2183 requests a GDB printf command, while "call" causes dprintf to call a
2184 function in the inferior. "agent" requests that the target agent
2185 (such as GDBserver) do the printing.
2187 set dprintf-function <expr>
2188 show dprintf-function
2189 set dprintf-channel <expr>
2190 show dprintf-channel
2191 Set the function and optional first argument to the call when using
2192 the "call" style of dynamic printf.
2194 set disconnected-dprintf on|off
2195 show disconnected-dprintf
2196 Control whether agent-style dynamic printfs continue to be in effect
2197 after GDB disconnects.
2199 * New configure options
2201 --with-auto-load-dir
2202 Configure default value for the 'set auto-load scripts-directory'
2203 setting above. It defaults to '$debugdir:$datadir/auto-load',
2204 $debugdir representing global debugging info directories (available
2205 via 'show debug-file-directory') and $datadir representing GDB's data
2206 directory (available via 'show data-directory').
2208 --with-auto-load-safe-path
2209 Configure default value for the 'set auto-load safe-path' setting
2210 above. It defaults to the --with-auto-load-dir setting.
2212 --without-auto-load-safe-path
2213 Set 'set auto-load safe-path' to '/', effectively disabling this
2216 * New remote packets
2218 z0/z1 conditional breakpoints extension
2220 The z0/z1 breakpoint insertion packets have been extended to carry
2221 a list of conditional expressions over to the remote stub depending on the
2222 condition evaluation mode. The use of this extension can be controlled
2223 via the "set remote conditional-breakpoints-packet" command.
2227 Specify the signals which the remote stub may pass to the debugged
2228 program without GDB involvement.
2230 * New command line options
2232 --init-command=FILE, -ix Like --command, -x but execute it
2233 before loading inferior.
2234 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2235 execute it before loading inferior.
2237 *** Changes in GDB 7.4
2239 * GDB now handles ambiguous linespecs more consistently; the existing
2240 FILE:LINE support has been expanded to other types of linespecs. A
2241 breakpoint will now be set on all matching locations in all
2242 inferiors, and locations will be added or removed according to
2245 * GDB now allows you to skip uninteresting functions and files when
2246 stepping with the "skip function" and "skip file" commands.
2248 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2249 and "show remote hardware-watchpoint-length-limit". These allows to
2250 set or show the maximum length limit (in bytes) of a remote
2251 target hardware watchpoint.
2253 This allows e.g. to use "unlimited" hardware watchpoints with the
2254 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2255 watchpoints are slower than real hardware watchpoints but are
2256 significantly faster than gdb software watchpoints.
2260 ** The register_pretty_printer function in module gdb.printing now takes
2261 an optional `replace' argument. If True, the new printer replaces any
2264 ** The "maint set python print-stack on|off" command has been
2265 deprecated and will be deleted in GDB 7.5.
2266 A new command: "set python print-stack none|full|message" has
2267 replaced it. Additionally, the default for "print-stack" is
2268 now "message", which just prints the error message without
2271 ** A prompt substitution hook (prompt_hook) is now available to the
2274 ** A new Python module, gdb.prompt has been added to the GDB Python
2275 modules library. This module provides functionality for
2276 escape sequences in prompts (used by set/show
2277 extended-prompt). These escape sequences are replaced by their
2278 corresponding value.
2280 ** Python commands and convenience-functions located in
2281 'data-directory'/python/gdb/command and
2282 'data-directory'/python/gdb/function are now automatically loaded
2285 ** Blocks now provide four new attributes. global_block and
2286 static_block will return the global and static blocks
2287 respectively. is_static and is_global are boolean attributes
2288 that indicate if the block is one of those two types.
2290 ** Symbols now provide the "type" attribute, the type of the symbol.
2292 ** The "gdb.breakpoint" function has been deprecated in favor of
2295 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2296 of a function. This class is based on the "finish" command
2297 available in the CLI.
2299 ** Type objects for struct and union types now allow access to
2300 the fields using standard Python dictionary (mapping) methods.
2301 For example, "some_type['myfield']" now works, as does
2302 "some_type.items()".
2304 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2307 ** A new function, "deep_items" has been added to the gdb.types
2308 module in the GDB Python modules library. This function returns
2309 an iterator over the fields of a struct or union type. Unlike
2310 the standard Python "iteritems" method, it will recursively traverse
2311 any anonymous fields.
2315 ** "*stopped" events can report several new "reason"s, such as
2318 ** Breakpoint changes are now notified using new async records, like
2319 "=breakpoint-modified".
2321 ** New command -ada-task-info.
2323 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2324 $sdir specifies the default system locations of shared libraries.
2325 $pdir specifies the directory where the libpthread used by the application
2328 GDB no longer looks in $sdir and $pdir after it has searched the directories
2329 mentioned in libthread-db-search-path. If you want to search those
2330 directories, they must be specified in libthread-db-search-path.
2331 The default value of libthread-db-search-path on GNU/Linux and Solaris
2332 systems is now "$sdir:$pdir".
2334 $pdir is not supported by gdbserver, it is currently ignored.
2335 $sdir is supported by gdbserver.
2337 * New configure option --with-iconv-bin.
2338 When using the internationalization support like the one in the GNU C
2339 library, GDB will invoke the "iconv" program to get a list of supported
2340 character sets. If this program lives in a non-standard location, one can
2341 use this option to specify where to find it.
2343 * When natively debugging programs on PowerPC BookE processors running
2344 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2345 watchpoints, which specify a mask in addition to an address to watch.
2346 The mask specifies that some bits of an address (the bits which are
2347 reset in the mask) should be ignored when matching the address accessed
2348 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2349 section in the user manual for more details.
2351 * The new option --once causes GDBserver to stop listening for connections once
2352 the first connection is made. The listening port used by GDBserver will
2353 become available after that.
2355 * New commands "info macros" and "alias" have been added.
2357 * New function parameters suffix @entry specifies value of function parameter
2358 at the time the function got called. Entry values are available only since
2364 "!" is now an alias of the "shell" command.
2365 Note that no space is needed between "!" and SHELL COMMAND.
2369 watch EXPRESSION mask MASK_VALUE
2370 The watch command now supports the mask argument which allows creation
2371 of masked watchpoints, if the current architecture supports this feature.
2373 info auto-load-scripts [REGEXP]
2374 This command was formerly named "maintenance print section-scripts".
2375 It is now generally useful and is no longer a maintenance-only command.
2377 info macro [-all] [--] MACRO
2378 The info macro command has new options `-all' and `--'. The first for
2379 printing all definitions of a macro. The second for explicitly specifying
2380 the end of arguments and the beginning of the macro name in case the macro
2381 name starts with a hyphen.
2383 collect[/s] EXPRESSIONS
2384 The tracepoint collect command now takes an optional modifier "/s"
2385 that directs it to dereference pointer-to-character types and
2386 collect the bytes of memory up to a zero byte. The behavior is
2387 similar to what you see when you use the regular print command on a
2388 string. An optional integer following the "/s" sets a bound on the
2389 number of bytes that will be collected.
2392 The trace start command now interprets any supplied arguments as a
2393 note to be recorded with the trace run, with an effect similar to
2394 setting the variable trace-notes.
2397 The trace stop command now interprets any arguments as a note to be
2398 mentioned along with the tstatus report that the trace was stopped
2399 with a command. The effect is similar to setting the variable
2402 * Tracepoints can now be enabled and disabled at any time after a trace
2403 experiment has been started using the standard "enable" and "disable"
2404 commands. It is now possible to start a trace experiment with no enabled
2405 tracepoints; GDB will display a warning, but will allow the experiment to
2406 begin, assuming that tracepoints will be enabled as needed while the trace
2409 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2410 locations with 4-byte instructions, when they were previously
2411 limited to locations with instructions of 5 bytes or longer.
2415 set debug dwarf2-read
2416 show debug dwarf2-read
2417 Turns on or off display of debugging messages related to reading
2418 DWARF debug info. The default is off.
2420 set debug symtab-create
2421 show debug symtab-create
2422 Turns on or off display of debugging messages related to symbol table
2423 creation. The default is off.
2426 show extended-prompt
2427 Set the GDB prompt, and allow escape sequences to be inserted to
2428 display miscellaneous information (see 'help set extended-prompt'
2429 for the list of sequences). This prompt (and any information
2430 accessed through the escape sequences) is updated every time the
2431 prompt is displayed.
2433 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2434 show print entry-values
2435 Set printing of frame argument values at function entry. In some cases
2436 GDB can determine the value of function argument which was passed by the
2437 function caller, even if the value was modified inside the called function.
2439 set debug entry-values
2440 show debug entry-values
2441 Control display of debugging info for determining frame argument values at
2442 function entry and virtual tail call frames.
2444 set basenames-may-differ
2445 show basenames-may-differ
2446 Set whether a source file may have multiple base names.
2447 (A "base name" is the name of a file with the directory part removed.
2448 Example: The base name of "/home/user/hello.c" is "hello.c".)
2449 If set, GDB will canonicalize file names (e.g., expand symlinks)
2450 before comparing them. Canonicalization is an expensive operation,
2451 but it allows the same file be known by more than one base name.
2452 If not set (the default), all source files are assumed to have just
2453 one base name, and gdb will do file name comparisons more efficiently.
2459 Set a user name and notes for the current and any future trace runs.
2460 This is useful for long-running and/or disconnected traces, to
2461 inform others (or yourself) as to who is running the trace, supply
2462 contact information, or otherwise explain what is going on.
2464 set trace-stop-notes
2465 show trace-stop-notes
2466 Set a note attached to the trace run, that is displayed when the
2467 trace has been stopped by a tstop command. This is useful for
2468 instance as an explanation, if you are stopping a trace run that was
2469 started by someone else.
2471 * New remote packets
2475 Dynamically enable a tracepoint in a started trace experiment.
2479 Dynamically disable a tracepoint in a started trace experiment.
2483 Set the user and notes of the trace run.
2487 Query the current status of a tracepoint.
2491 Query the minimum length of instruction at which a fast tracepoint may
2494 * Dcache size (number of lines) and line-size are now runtime-configurable
2495 via "set dcache line" and "set dcache line-size" commands.
2499 Texas Instruments TMS320C6x tic6x-*-*
2503 Renesas RL78 rl78-*-elf
2505 *** Changes in GDB 7.3.1
2507 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2509 *** Changes in GDB 7.3
2511 * GDB has a new command: "thread find [REGEXP]".
2512 It finds the thread id whose name, target id, or thread extra info
2513 matches the given regular expression.
2515 * The "catch syscall" command now works on mips*-linux* targets.
2517 * The -data-disassemble MI command now supports modes 2 and 3 for
2518 dumping the instruction opcodes.
2520 * New command line options
2522 -data-directory DIR Specify DIR as the "data-directory".
2523 This is mostly for testing purposes.
2525 * The "maint set python auto-load on|off" command has been renamed to
2526 "set auto-load-scripts on|off".
2528 * GDB has a new command: "set directories".
2529 It is like the "dir" command except that it replaces the
2530 source path list instead of augmenting it.
2532 * GDB now understands thread names.
2534 On GNU/Linux, "info threads" will display the thread name as set by
2535 prctl or pthread_setname_np.
2537 There is also a new command, "thread name", which can be used to
2538 assign a name internally for GDB to display.
2541 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2542 has been integrated into GDB.
2546 ** The function gdb.Write now accepts an optional keyword 'stream'.
2547 This keyword, when provided, will direct the output to either
2548 stdout, stderr, or GDB's logging output.
2550 ** Parameters can now be be sub-classed in Python, and in particular
2551 you may implement the get_set_doc and get_show_doc functions.
2552 This improves how Parameter set/show documentation is processed
2553 and allows for more dynamic content.
2555 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2556 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2557 have an is_valid method.
2559 ** Breakpoints can now be sub-classed in Python, and in particular
2560 you may implement a 'stop' function that is executed each time
2561 the inferior reaches that breakpoint.
2563 ** New function gdb.lookup_global_symbol looks up a global symbol.
2565 ** GDB values in Python are now callable if the value represents a
2566 function. For example, if 'some_value' represents a function that
2567 takes two integer parameters and returns a value, you can call
2568 that function like so:
2570 result = some_value (10,20)
2572 ** Module gdb.types has been added.
2573 It contains a collection of utilities for working with gdb.Types objects:
2574 get_basic_type, has_field, make_enum_dict.
2576 ** Module gdb.printing has been added.
2577 It contains utilities for writing and registering pretty-printers.
2578 New classes: PrettyPrinter, SubPrettyPrinter,
2579 RegexpCollectionPrettyPrinter.
2580 New function: register_pretty_printer.
2582 ** New commands "info pretty-printers", "enable pretty-printer" and
2583 "disable pretty-printer" have been added.
2585 ** gdb.parameter("directories") is now available.
2587 ** New function gdb.newest_frame returns the newest frame in the
2590 ** The gdb.InferiorThread class has a new "name" attribute. This
2591 holds the thread's name.
2593 ** Python Support for Inferior events.
2594 Python scripts can add observers to be notified of events
2595 occurring in the process being debugged.
2596 The following events are currently supported:
2597 - gdb.events.cont Continue event.
2598 - gdb.events.exited Inferior exited event.
2599 - gdb.events.stop Signal received, and Breakpoint hit events.
2603 ** GDB now puts template parameters in scope when debugging in an
2604 instantiation. For example, if you have:
2606 template<int X> int func (void) { return X; }
2608 then if you step into func<5>, "print X" will show "5". This
2609 feature requires proper debuginfo support from the compiler; it
2610 was added to GCC 4.5.
2612 ** The motion commands "next", "finish", "until", and "advance" now
2613 work better when exceptions are thrown. In particular, GDB will
2614 no longer lose control of the inferior; instead, the GDB will
2615 stop the inferior at the point at which the exception is caught.
2616 This functionality requires a change in the exception handling
2617 code that was introduced in GCC 4.5.
2619 * GDB now follows GCC's rules on accessing volatile objects when
2620 reading or writing target state during expression evaluation.
2621 One notable difference to prior behavior is that "print x = 0"
2622 no longer generates a read of x; the value of the assignment is
2623 now always taken directly from the value being assigned.
2625 * GDB now has some support for using labels in the program's source in
2626 linespecs. For instance, you can use "advance label" to continue
2627 execution to a label.
2629 * GDB now has support for reading and writing a new .gdb_index
2630 section. This section holds a fast index of DWARF debugging
2631 information and can be used to greatly speed up GDB startup and
2632 operation. See the documentation for `save gdb-index' for details.
2634 * The "watch" command now accepts an optional "-location" argument.
2635 When used, this causes GDB to watch the memory referred to by the
2636 expression. Such a watchpoint is never deleted due to it going out
2639 * GDB now supports thread debugging of core dumps on GNU/Linux.
2641 GDB now activates thread debugging using the libthread_db library
2642 when debugging GNU/Linux core dumps, similarly to when debugging
2643 live processes. As a result, when debugging a core dump file, GDB
2644 is now able to display pthread_t ids of threads. For example, "info
2645 threads" shows the same output as when debugging the process when it
2646 was live. In earlier releases, you'd see something like this:
2649 * 1 LWP 6780 main () at main.c:10
2651 While now you see this:
2654 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2656 It is also now possible to inspect TLS variables when debugging core
2659 When debugging a core dump generated on a machine other than the one
2660 used to run GDB, you may need to point GDB at the correct
2661 libthread_db library with the "set libthread-db-search-path"
2662 command. See the user manual for more details on this command.
2664 * When natively debugging programs on PowerPC BookE processors running
2665 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2666 which stop execution of the inferior whenever it executes an instruction
2667 at any address within the specified range. See the "PowerPC Embedded"
2668 section in the user manual for more details.
2670 * New features in the GDB remote stub, GDBserver
2672 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2673 and i686 LynxOS (version 5.x).
2675 ** GDBserver is now supported on Blackfin Linux.
2677 * New native configurations
2679 ia64 HP-UX ia64-*-hpux*
2683 Analog Devices, Inc. Blackfin Processor bfin-*
2685 * Ada task switching is now supported on sparc-elf targets when
2686 debugging a program using the Ravenscar Profile. For more information,
2687 see the "Tasking Support when using the Ravenscar Profile" section
2688 in the GDB user manual.
2690 * Guile support was removed.
2692 * New features in the GNU simulator
2694 ** The --map-info flag lists all known core mappings.
2696 ** CFI flashes may be simulated via the "cfi" device.
2698 *** Changes in GDB 7.2
2700 * Shared library support for remote targets by default
2702 When GDB is configured for a generic, non-OS specific target, like
2703 for example, --target=arm-eabi or one of the many *-*-elf targets,
2704 GDB now queries remote stubs for loaded shared libraries using the
2705 `qXfer:libraries:read' packet. Previously, shared library support
2706 was always disabled for such configurations.
2710 ** Argument Dependent Lookup (ADL)
2712 In C++ ADL lookup directs function search to the namespaces of its
2713 arguments even if the namespace has not been imported.
2723 Here the compiler will search for `foo' in the namespace of 'b'
2724 and find A::foo. GDB now supports this. This construct is commonly
2725 used in the Standard Template Library for operators.
2727 ** Improved User Defined Operator Support
2729 In addition to member operators, GDB now supports lookup of operators
2730 defined in a namespace and imported with a `using' directive, operators
2731 defined in the global scope, operators imported implicitly from an
2732 anonymous namespace, and the ADL operators mentioned in the previous
2734 GDB now also supports proper overload resolution for all the previously
2735 mentioned flavors of operators.
2737 ** static const class members
2739 Printing of static const class members that are initialized in the
2740 class definition has been fixed.
2742 * Windows Thread Information Block access.
2744 On Windows targets, GDB now supports displaying the Windows Thread
2745 Information Block (TIB) structure. This structure is visible either
2746 by using the new command `info w32 thread-information-block' or, by
2747 dereferencing the new convenience variable named `$_tlb', a
2748 thread-specific pointer to the TIB. This feature is also supported
2749 when remote debugging using GDBserver.
2751 * Static tracepoints
2753 Static tracepoints are calls in the user program into a tracing
2754 library. One such library is a port of the LTTng kernel tracer to
2755 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2756 When debugging with GDBserver, GDB now supports combining the GDB
2757 tracepoint machinery with such libraries. For example: the user can
2758 use GDB to probe a static tracepoint marker (a call from the user
2759 program into the tracing library) with the new "strace" command (see
2760 "New commands" below). This creates a "static tracepoint" in the
2761 breakpoint list, that can be manipulated with the same feature set
2762 as fast and regular tracepoints. E.g., collect registers, local and
2763 global variables, collect trace state variables, and define
2764 tracepoint conditions. In addition, the user can collect extra
2765 static tracepoint marker specific data, by collecting the new
2766 $_sdata internal variable. When analyzing the trace buffer, you can
2767 inspect $_sdata like any other variable available to GDB. For more
2768 information, see the "Tracepoints" chapter in GDB user manual. New
2769 remote packets have been defined to support static tracepoints, see
2770 the "New remote packets" section below.
2772 * Better reconstruction of tracepoints after disconnected tracing
2774 GDB will attempt to download the original source form of tracepoint
2775 definitions when starting a trace run, and then will upload these
2776 upon reconnection to the target, resulting in a more accurate
2777 reconstruction of the tracepoints that are in use on the target.
2781 You can now exercise direct control over the ways that GDB can
2782 affect your program. For instance, you can disallow the setting of
2783 breakpoints, so that the program can run continuously (assuming
2784 non-stop mode). In addition, the "observer" variable is available
2785 to switch all of the different controls; in observer mode, GDB
2786 cannot affect the target's behavior at all, which is useful for
2787 tasks like diagnosing live systems in the field.
2789 * The new convenience variable $_thread holds the number of the
2792 * New remote packets
2796 Return the address of the Windows Thread Information Block of a given thread.
2800 In response to several of the tracepoint packets, the target may now
2801 also respond with a number of intermediate `qRelocInsn' request
2802 packets before the final result packet, to have GDB handle
2803 relocating an instruction to execute at a different address. This
2804 is particularly useful for stubs that support fast tracepoints. GDB
2805 reports support for this feature in the qSupported packet.
2809 List static tracepoint markers in the target program.
2813 List static tracepoint markers at a given address in the target
2816 qXfer:statictrace:read
2818 Read the static trace data collected (by a `collect $_sdata'
2819 tracepoint action). The remote stub reports support for this packet
2820 to gdb's qSupported query.
2824 Send the current settings of GDB's permission flags.
2828 Send part of the source (textual) form of a tracepoint definition,
2829 which includes location, conditional, and action list.
2831 * The source command now accepts a -s option to force searching for the
2832 script in the source search path even if the script name specifies
2835 * New features in the GDB remote stub, GDBserver
2837 - GDBserver now support tracepoints (including fast tracepoints, and
2838 static tracepoints). The feature is currently supported by the
2839 i386-linux and amd64-linux builds. See the "Tracepoints support
2840 in gdbserver" section in the manual for more information.
2842 GDBserver JIT compiles the tracepoint's conditional agent
2843 expression bytecode into native code whenever possible for low
2844 overhead dynamic tracepoints conditionals. For such tracepoints,
2845 an expression that examines program state is evaluated when the
2846 tracepoint is reached, in order to determine whether to capture
2847 trace data. If the condition is simple and false, processing the
2848 tracepoint finishes very quickly and no data is gathered.
2850 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2851 for static tracepoints support.
2853 - GDBserver now supports x86_64 Windows 64-bit debugging.
2855 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2856 it understands register description.
2858 * The --batch flag now disables pagination and queries.
2860 * X86 general purpose registers
2862 GDB now supports reading/writing byte, word and double-word x86
2863 general purpose registers directly. This means you can use, say,
2864 $ah or $ax to refer, respectively, to the byte register AH and
2865 16-bit word register AX that are actually portions of the 32-bit
2866 register EAX or 64-bit register RAX.
2868 * The `commands' command now accepts a range of breakpoints to modify.
2869 A plain `commands' following a command that creates multiple
2870 breakpoints affects all the breakpoints set by that command. This
2871 applies to breakpoints set by `rbreak', and also applies when a
2872 single `break' command creates multiple breakpoints (e.g.,
2873 breakpoints on overloaded c++ functions).
2875 * The `rbreak' command now accepts a filename specification as part of
2876 its argument, limiting the functions selected by the regex to those
2877 in the specified file.
2879 * Support for remote debugging Windows and SymbianOS shared libraries
2880 from Unix hosts has been improved. Non Windows GDB builds now can
2881 understand target reported file names that follow MS-DOS based file
2882 system semantics, such as file names that include drive letters and
2883 use the backslash character as directory separator. This makes it
2884 possible to transparently use the "set sysroot" and "set
2885 solib-search-path" on Unix hosts to point as host copies of the
2886 target's shared libraries. See the new command "set
2887 target-file-system-kind" described below, and the "Commands to
2888 specify files" section in the user manual for more information.
2892 eval template, expressions...
2893 Convert the values of one or more expressions under the control
2894 of the string template to a command line, and call it.
2896 set target-file-system-kind unix|dos-based|auto
2897 show target-file-system-kind
2898 Set or show the assumed file system kind for target reported file
2901 save breakpoints <filename>
2902 Save all current breakpoint definitions to a file suitable for use
2903 in a later debugging session. To read the saved breakpoint
2904 definitions, use the `source' command.
2906 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2909 info static-tracepoint-markers
2910 Display information about static tracepoint markers in the target.
2912 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2913 Define a static tracepoint by probing a marker at the given
2914 function, line, address, or marker ID.
2918 Enable and disable observer mode.
2920 set may-write-registers on|off
2921 set may-write-memory on|off
2922 set may-insert-breakpoints on|off
2923 set may-insert-tracepoints on|off
2924 set may-insert-fast-tracepoints on|off
2925 set may-interrupt on|off
2926 Set individual permissions for GDB effects on the target. Note that
2927 some of these settings can have undesirable or surprising
2928 consequences, particularly when changed in the middle of a session.
2929 For instance, disabling the writing of memory can prevent
2930 breakpoints from being inserted, cause single-stepping to fail, or
2931 even crash your program, if you disable after breakpoints have been
2932 inserted. However, GDB should not crash.
2934 set record memory-query on|off
2935 show record memory-query
2936 Control whether to stop the inferior if memory changes caused
2937 by an instruction cannot be recorded.
2942 The disassemble command now supports "start,+length" form of two arguments.
2946 ** GDB now provides a new directory location, called the python directory,
2947 where Python scripts written for GDB can be installed. The location
2948 of that directory is <data-directory>/python, where <data-directory>
2949 is the GDB data directory. For more details, see section `Scripting
2950 GDB using Python' in the manual.
2952 ** The GDB Python API now has access to breakpoints, symbols, symbol
2953 tables, program spaces, inferiors, threads and frame's code blocks.
2954 Additionally, GDB Parameters can now be created from the API, and
2955 manipulated via set/show in the CLI.
2957 ** New functions gdb.target_charset, gdb.target_wide_charset,
2958 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2960 ** New exception gdb.GdbError.
2962 ** Pretty-printers are now also looked up in the current program space.
2964 ** Pretty-printers can now be individually enabled and disabled.
2966 ** GDB now looks for names of Python scripts to auto-load in a
2967 special section named `.debug_gdb_scripts', in addition to looking
2968 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2970 * Tracepoint actions were unified with breakpoint commands. In particular,
2971 there are no longer differences in "info break" output for breakpoints and
2972 tracepoints and the "commands" command can be used for both tracepoints and
2973 regular breakpoints.
2977 ARM Symbian arm*-*-symbianelf*
2979 * D language support.
2980 GDB now supports debugging programs written in the D programming
2983 * GDB now supports the extended ptrace interface for PowerPC which is
2984 available since Linux kernel version 2.6.34. This automatically enables
2985 any hardware breakpoints and additional hardware watchpoints available in
2986 the processor. The old ptrace interface exposes just one hardware
2987 watchpoint and no hardware breakpoints.
2989 * GDB is now able to use the Data Value Compare (DVC) register available on
2990 embedded PowerPC processors to implement in hardware simple watchpoint
2991 conditions of the form:
2993 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2995 This works in native GDB running on Linux kernels with the extended ptrace
2996 interface mentioned above.
2998 *** Changes in GDB 7.1
3002 ** Namespace Support
3004 GDB now supports importing of namespaces in C++. This enables the
3005 user to inspect variables from imported namespaces. Support for
3006 namepace aliasing has also been added. So, if a namespace is
3007 aliased in the current scope (e.g. namepace C=A; ) the user can
3008 print variables using the alias (e.g. (gdb) print C::x).
3012 All known bugs relating to the printing of virtual base class were
3013 fixed. It is now possible to call overloaded static methods using a
3018 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3019 and reinterpret_cast<> are now handled by the C++ expression parser.
3023 Xilinx MicroBlaze microblaze-*-*
3028 Xilinx MicroBlaze microblaze
3031 * Multi-program debugging.
3033 GDB now has support for multi-program (a.k.a. multi-executable or
3034 multi-exec) debugging. This allows for debugging multiple inferiors
3035 simultaneously each running a different program under the same GDB
3036 session. See "Debugging Multiple Inferiors and Programs" in the
3037 manual for more information. This implied some user visible changes
3038 in the multi-inferior support. For example, "info inferiors" now
3039 lists inferiors that are not running yet or that have exited
3040 already. See also "New commands" and "New options" below.
3042 * New tracing features
3044 GDB's tracepoint facility now includes several new features:
3046 ** Trace state variables
3048 GDB tracepoints now include support for trace state variables, which
3049 are variables managed by the target agent during a tracing
3050 experiment. They are useful for tracepoints that trigger each
3051 other, so for instance one tracepoint can count hits in a variable,
3052 and then a second tracepoint has a condition that is true when the
3053 count reaches a particular value. Trace state variables share the
3054 $-syntax of GDB convenience variables, and can appear in both
3055 tracepoint actions and condition expressions. Use the "tvariable"
3056 command to create, and "info tvariables" to view; see "Trace State
3057 Variables" in the manual for more detail.
3061 GDB now includes an option for defining fast tracepoints, which
3062 targets may implement more efficiently, such as by installing a jump
3063 into the target agent rather than a trap instruction. The resulting
3064 speedup can be by two orders of magnitude or more, although the
3065 tradeoff is that some program locations on some target architectures
3066 might not allow fast tracepoint installation, for instance if the
3067 instruction to be replaced is shorter than the jump. To request a
3068 fast tracepoint, use the "ftrace" command, with syntax identical to
3069 the regular trace command.
3071 ** Disconnected tracing
3073 It is now possible to detach GDB from the target while it is running
3074 a trace experiment, then reconnect later to see how the experiment
3075 is going. In addition, a new variable disconnected-tracing lets you
3076 tell the target agent whether to continue running a trace if the
3077 connection is lost unexpectedly.
3081 GDB now has the ability to save the trace buffer into a file, and
3082 then use that file as a target, similarly to you can do with
3083 corefiles. You can select trace frames, print data that was
3084 collected in them, and use tstatus to display the state of the
3085 tracing run at the moment that it was saved. To create a trace
3086 file, use "tsave <filename>", and to use it, do "target tfile
3089 ** Circular trace buffer
3091 You can ask the target agent to handle the trace buffer as a
3092 circular buffer, discarding the oldest trace frames to make room for
3093 newer ones, by setting circular-trace-buffer to on. This feature may
3094 not be available for all target agents.
3099 The disassemble command, when invoked with two arguments, now requires
3100 the arguments to be comma-separated.
3103 The info variables command now displays variable definitions. Files
3104 which only declare a variable are not shown.
3107 The source command is now capable of sourcing Python scripts.
3108 This feature is dependent on the debugger being build with Python
3111 Related to this enhancement is also the introduction of a new command
3112 "set script-extension" (see below).
3114 * New commands (for set/show, see "New options" below)
3116 record save [<FILENAME>]
3117 Save a file (in core file format) containing the process record
3118 execution log for replay debugging at a later time.
3120 record restore <FILENAME>
3121 Restore the process record execution log that was saved at an
3122 earlier time, for replay debugging.
3124 add-inferior [-copies <N>] [-exec <FILENAME>]
3127 clone-inferior [-copies <N>] [ID]
3128 Make a new inferior ready to execute the same program another
3129 inferior has loaded.
3134 maint info program-spaces
3135 List the program spaces loaded into GDB.
3137 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3138 show remote interrupt-sequence
3139 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3140 as the sequence to the remote target in order to interrupt the execution.
3141 Ctrl-C is a default. Some system prefers BREAK which is high level of
3142 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3143 Magic SysRq g. It is BREAK signal and character 'g'.
3145 set remote interrupt-on-connect [on | off]
3146 show remote interrupt-on-connect
3147 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3148 remote target when gdb connects to it. This is needed when you debug
3151 set remotebreak [on | off]
3153 Deprecated. Use "set/show remote interrupt-sequence" instead.
3155 tvariable $NAME [ = EXP ]
3156 Create or modify a trace state variable.
3159 List trace state variables and their values.
3161 delete tvariable $NAME ...
3162 Delete one or more trace state variables.
3165 Evaluate the given expressions without collecting anything into the
3166 trace buffer. (Valid in tracepoint actions only.)
3168 ftrace FN / FILE:LINE / *ADDR
3169 Define a fast tracepoint at the given function, line, or address.
3171 * New expression syntax
3173 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3174 GDB now parses 0b101010 identically with 42.
3178 set follow-exec-mode new|same
3179 show follow-exec-mode
3180 Control whether GDB reuses the same inferior across an exec call or
3181 creates a new one. This is useful to be able to restart the old
3182 executable after the inferior having done an exec call.
3184 set default-collect EXPR, ...
3185 show default-collect
3186 Define a list of expressions to be collected at each tracepoint.
3187 This is a useful way to ensure essential items are not overlooked,
3188 such as registers or a critical global variable.
3190 set disconnected-tracing
3191 show disconnected-tracing
3192 If set to 1, the target is instructed to continue tracing if it
3193 loses its connection to GDB. If 0, the target is to stop tracing
3196 set circular-trace-buffer
3197 show circular-trace-buffer
3198 If set to on, the target is instructed to use a circular trace buffer
3199 and discard the oldest trace frames instead of stopping the trace due
3200 to a full trace buffer. If set to off, the trace stops when the buffer
3201 fills up. Some targets may not support this.
3203 set script-extension off|soft|strict
3204 show script-extension
3205 If set to "off", the debugger does not perform any script language
3206 recognition, and all sourced files are assumed to be GDB scripts.
3207 If set to "soft" (the default), files are sourced according to
3208 filename extension, falling back to GDB scripts if the first
3210 If set to "strict", files are sourced according to filename extension.
3212 set ada trust-PAD-over-XVS on|off
3213 show ada trust-PAD-over-XVS
3214 If off, activate a workaround against a bug in the debugging information
3215 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3216 the GCC sources for more information about the GNAT encoding and
3217 PAD types in particular). It is always safe to set this option to
3218 off, but this introduces a slight performance penalty. The default
3221 * Python API Improvements
3223 ** GDB provides the new class gdb.LazyString. This is useful in
3224 some pretty-printing cases. The new method gdb.Value.lazy_string
3225 provides a simple way to create objects of this type.
3227 ** The fields returned by gdb.Type.fields now have an
3228 `is_base_class' attribute.
3230 ** The new method gdb.Type.range returns the range of an array type.
3232 ** The new method gdb.parse_and_eval can be used to parse and
3233 evaluate an expression.
3235 * New remote packets
3238 Define a trace state variable.
3241 Get the current value of a trace state variable.
3244 Set desired tracing behavior upon disconnection.
3247 Set the trace buffer to be linear or circular.
3250 Get data about the tracepoints currently in use.
3254 Process record now works correctly with hardware watchpoints.
3256 Multiple bug fixes have been made to the mips-irix port, making it
3257 much more reliable. In particular:
3258 - Debugging threaded applications is now possible again. Previously,
3259 GDB would hang while starting the program, or while waiting for
3260 the program to stop at a breakpoint.
3261 - Attaching to a running process no longer hangs.
3262 - An error occurring while loading a core file has been fixed.
3263 - Changing the value of the PC register now works again. This fixes
3264 problems observed when using the "jump" command, or when calling
3265 a function from GDB, or even when assigning a new value to $pc.
3266 - With the "finish" and "return" commands, the return value for functions
3267 returning a small array is now correctly printed.
3268 - It is now possible to break on shared library code which gets executed
3269 during a shared library init phase (code executed while executing
3270 their .init section). Previously, the breakpoint would have no effect.
3271 - GDB is now able to backtrace through the signal handler for
3272 non-threaded programs.
3274 PIE (Position Independent Executable) programs debugging is now supported.
3275 This includes debugging execution of PIC (Position Independent Code) shared
3276 libraries although for that, it should be possible to run such libraries as an
3279 *** Changes in GDB 7.0
3281 * GDB now has an interface for JIT compilation. Applications that
3282 dynamically generate code can create symbol files in memory and register
3283 them with GDB. For users, the feature should work transparently, and
3284 for JIT developers, the interface is documented in the GDB manual in the
3285 "JIT Compilation Interface" chapter.
3287 * Tracepoints may now be conditional. The syntax is as for
3288 breakpoints; either an "if" clause appended to the "trace" command,
3289 or the "condition" command is available. GDB sends the condition to
3290 the target for evaluation using the same bytecode format as is used
3291 for tracepoint actions.
3293 * The disassemble command now supports: an optional /r modifier, print the
3294 raw instructions in hex as well as in symbolic form, and an optional /m
3295 modifier to print mixed source+assembly.
3297 * Process record and replay
3299 In a architecture environment that supports ``process record and
3300 replay'', ``process record and replay'' target can record a log of
3301 the process execution, and replay it with both forward and reverse
3304 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3305 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3306 set execution-direction {forward|reverse}, for targets that support
3309 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3310 feature is available with a native GDB running on kernel version
3313 * GDB now has support for multi-byte and wide character sets on the
3314 target. Strings whose character type is wchar_t, char16_t, or
3315 char32_t are now correctly printed. GDB supports wide- and unicode-
3316 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3317 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3318 `printf'. This feature requires iconv to work properly; if your
3319 system does not have a working iconv, GDB can use GNU libiconv. See
3320 the installation instructions for more information.
3322 * GDB now supports automatic retrieval of shared library files from
3323 remote targets. To use this feature, specify a system root that begins
3324 with the `remote:' prefix, either via the `set sysroot' command or via
3325 the `--with-sysroot' configure-time option.
3327 * "info sharedlibrary" now takes an optional regex of libraries to show,
3328 and it now reports if a shared library has no debugging information.
3330 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3331 now complete on file names.
3333 * When completing in expressions, gdb will attempt to limit
3334 completions to allowable structure or union fields, where appropriate.
3335 For instance, consider:
3337 # struct example { int f1; double f2; };
3338 # struct example variable;
3341 If the user types TAB at the end of this command line, the available
3342 completions will be "f1" and "f2".
3344 * Inlined functions are now supported. They show up in backtraces, and
3345 the "step", "next", and "finish" commands handle them automatically.
3347 * GDB now supports the token-splicing (##) and stringification (#)
3348 operators when expanding macros. It also supports variable-arity
3351 * GDB now supports inspecting extra signal information, exported by
3352 the new $_siginfo convenience variable. The feature is currently
3353 implemented on linux ARM, i386 and amd64.
3355 * GDB can now display the VFP floating point registers and NEON vector
3356 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3357 can provide these registers (requires Linux 2.6.30 or later). Remote
3358 and simulator targets may also provide them.
3360 * New remote packets
3363 Search memory for a sequence of bytes.
3366 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3367 operation over reliable transport links. Use of this packet is
3368 controlled by the `set remote noack-packet' command.
3371 Kill the process with the specified process ID. Use this in preference
3372 to `k' when multiprocess protocol extensions are supported.
3375 Obtains additional operating system information
3379 Read or write additional signal information.
3381 * Removed remote protocol undocumented extension
3383 An undocumented extension to the remote protocol's `S' stop reply
3384 packet that permited the stub to pass a process id was removed.
3385 Remote servers should use the `T' stop reply packet instead.
3387 * GDB now supports multiple function calling conventions according to the
3388 DWARF-2 DW_AT_calling_convention function attribute.
3390 * The SH target utilizes the aforementioned change to distinguish between gcc
3391 and Renesas calling convention. It also adds the new CLI commands
3392 `set/show sh calling-convention'.
3394 * GDB can now read compressed debug sections, as produced by GNU gold
3395 with the --compress-debug-sections=zlib flag.
3397 * 64-bit core files are now supported on AIX.
3399 * Thread switching is now supported on Tru64.
3401 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3402 which will be allocated using malloc later in program execution.
3404 * The qXfer:libraries:read remote procotol packet now allows passing a
3405 list of section offsets.
3407 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3408 conditions handling signals delivered during attach or thread creation
3409 have also been fixed.
3411 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3412 From the user's standpoint, all unqualified instances of True and False
3413 are treated as the standard definitions, regardless of context.
3415 * GDB now parses C++ symbol and type names more flexibly. For
3418 template<typename T> class C { };
3421 GDB will now correctly handle all of:
3423 ptype C<char const *>
3424 ptype C<char const*>
3425 ptype C<const char *>
3426 ptype C<const char*>
3428 * New features in the GDB remote stub, gdbserver
3430 - The "--wrapper" command-line argument tells gdbserver to use a
3431 wrapper program to launch programs for debugging.
3433 - On PowerPC and S/390 targets, it is now possible to use a single
3434 gdbserver executable to debug both 32-bit and 64-bit programs.
3435 (This requires gdbserver itself to be built as a 64-bit executable.)
3437 - gdbserver uses the new noack protocol mode for TCP connections to
3438 reduce communications latency, if also supported and enabled in GDB.
3440 - Support for the sparc64-linux-gnu target is now included in
3443 - The amd64-linux build of gdbserver now supports debugging both
3444 32-bit and 64-bit programs.
3446 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3447 now support hardware watchpoints, and will use them automatically
3452 GDB now has support for scripting using Python. Whether this is
3453 available is determined at configure time.
3455 New GDB commands can now be written in Python.
3457 * Ada tasking support
3459 Ada tasks can now be inspected in GDB. The following commands have
3463 Print the list of Ada tasks.
3465 Print detailed information about task number N.
3467 Print the task number of the current task.
3469 Switch the context of debugging to task number N.
3471 * Support for user-defined prefixed commands. The "define" command can
3472 add new commands to existing prefixes, e.g. "target".
3474 * Multi-inferior, multi-process debugging.
3476 GDB now has generalized support for multi-inferior debugging. See
3477 "Debugging Multiple Inferiors" in the manual for more information.
3478 Although availability still depends on target support, the command
3479 set is more uniform now. The GNU/Linux specific multi-forks support
3480 has been migrated to this new framework. This implied some user
3481 visible changes; see "New commands" and also "Removed commands"
3484 * Target descriptions can now describe the target OS ABI. See the
3485 "Target Description Format" section in the user manual for more
3488 * Target descriptions can now describe "compatible" architectures
3489 to indicate that the target can execute applications for a different
3490 architecture in addition to those for the main target architecture.
3491 See the "Target Description Format" section in the user manual for
3494 * Multi-architecture debugging.
3496 GDB now includes general supports for debugging applications on
3497 hybrid systems that use more than one single processor architecture
3498 at the same time. Each such hybrid architecture still requires
3499 specific support to be added. The only hybrid architecture supported
3500 in this version of GDB is the Cell Broadband Engine.
3502 * GDB now supports integrated debugging of Cell/B.E. applications that
3503 use both the PPU and SPU architectures. To enable support for hybrid
3504 Cell/B.E. debugging, you need to configure GDB to support both the
3505 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3506 --enable-targets configure option.
3508 * Non-stop mode debugging.
3510 For some targets, GDB now supports an optional mode of operation in
3511 which you can examine stopped threads while other threads continue
3512 to execute freely. This is referred to as non-stop mode, with the
3513 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3514 section in the user manual for more information.
3516 To be able to support remote non-stop debugging, a remote stub needs
3517 to implement the non-stop mode remote protocol extensions, as
3518 described in the "Remote Non-Stop" section of the user manual. The
3519 GDB remote stub, gdbserver, has been adjusted to support these
3520 extensions on linux targets.
3522 * New commands (for set/show, see "New options" below)
3524 catch syscall [NAME(S) | NUMBER(S)]
3525 Catch system calls. Arguments, which should be names of system
3526 calls or their numbers, mean catch only those syscalls. Without
3527 arguments, every syscall will be caught. When the inferior issues
3528 any of the specified syscalls, GDB will stop and announce the system
3529 call, both when it is called and when its call returns. This
3530 feature is currently available with a native GDB running on the
3531 Linux Kernel, under the following architectures: x86, x86_64,
3532 PowerPC and PowerPC64.
3534 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3536 Search memory for a sequence of bytes.
3538 maint set python print-stack
3539 maint show python print-stack
3540 Show a stack trace when an error is encountered in a Python script.
3543 Invoke CODE by passing it to the Python interpreter.
3548 These allow macros to be defined, undefined, and listed
3552 Show operating system information about processes.
3555 List the inferiors currently under GDB's control.
3558 Switch focus to inferior number NUM.
3561 Detach from inferior number NUM.
3564 Kill inferior number NUM.
3568 set spu stop-on-load
3569 show spu stop-on-load
3570 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3572 set spu auto-flush-cache
3573 show spu auto-flush-cache
3574 Control whether to automatically flush the software-managed cache
3575 during Cell/B.E. debugging.
3577 set sh calling-convention
3578 show sh calling-convention
3579 Control the calling convention used when calling SH target functions.
3582 show debug timestamp
3583 Control display of timestamps with GDB debugging output.
3585 set disassemble-next-line
3586 show disassemble-next-line
3587 Control display of disassembled source lines or instructions when
3590 set remote noack-packet
3591 show remote noack-packet
3592 Set/show the use of remote protocol QStartNoAckMode packet. See above
3593 under "New remote packets."
3595 set remote query-attached-packet
3596 show remote query-attached-packet
3597 Control use of remote protocol `qAttached' (query-attached) packet.
3599 set remote read-siginfo-object
3600 show remote read-siginfo-object
3601 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3604 set remote write-siginfo-object
3605 show remote write-siginfo-object
3606 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3609 set remote reverse-continue
3610 show remote reverse-continue
3611 Control use of remote protocol 'bc' (reverse-continue) packet.
3613 set remote reverse-step
3614 show remote reverse-step
3615 Control use of remote protocol 'bs' (reverse-step) packet.
3617 set displaced-stepping
3618 show displaced-stepping
3619 Control displaced stepping mode. Displaced stepping is a way to
3620 single-step over breakpoints without removing them from the debuggee.
3621 Also known as "out-of-line single-stepping".
3624 show debug displaced
3625 Control display of debugging info for displaced stepping.
3627 maint set internal-error
3628 maint show internal-error
3629 Control what GDB does when an internal error is detected.
3631 maint set internal-warning
3632 maint show internal-warning
3633 Control what GDB does when an internal warning is detected.
3638 Use a wrapper program to launch programs for debugging.
3640 set multiple-symbols (all|ask|cancel)
3641 show multiple-symbols
3642 The value of this variable can be changed to adjust the debugger behavior
3643 when an expression or a breakpoint location contains an ambiguous symbol
3644 name (an overloaded function name, for instance).
3646 set breakpoint always-inserted
3647 show breakpoint always-inserted
3648 Keep breakpoints always inserted in the target, as opposed to inserting
3649 them when resuming the target, and removing them when the target stops.
3650 This option can improve debugger performance on slow remote targets.
3652 set arm fallback-mode (arm|thumb|auto)
3653 show arm fallback-mode
3654 set arm force-mode (arm|thumb|auto)
3656 These commands control how ARM GDB determines whether instructions
3657 are ARM or Thumb. The default for both settings is auto, which uses
3658 the current CPSR value for instructions without symbols; previous
3659 versions of GDB behaved as if "set arm fallback-mode arm".
3661 set disable-randomization
3662 show disable-randomization
3663 Standalone programs run with the virtual address space randomization enabled
3664 by default on some platforms. This option keeps the addresses stable across
3665 multiple debugging sessions.
3669 Control whether other threads are stopped or not when some thread hits
3674 Requests that asynchronous execution is enabled in the target, if available.
3675 In this case, it's possible to resume target in the background, and interact
3676 with GDB while the target is running. "show target-async" displays the
3677 current state of asynchronous execution of the target.
3679 set target-wide-charset
3680 show target-wide-charset
3681 The target-wide-charset is the name of the character set that GDB
3682 uses when printing characters whose type is wchar_t.
3684 set tcp auto-retry (on|off)
3686 set tcp connect-timeout
3687 show tcp connect-timeout
3688 These commands allow GDB to retry failed TCP connections to a remote stub
3689 with a specified timeout period; this is useful if the stub is launched
3690 in parallel with GDB but may not be ready to accept connections immediately.
3692 set libthread-db-search-path
3693 show libthread-db-search-path
3694 Control list of directories which GDB will search for appropriate
3697 set schedule-multiple (on|off)
3698 show schedule-multiple
3699 Allow GDB to resume all threads of all processes or only threads of
3700 the current process.
3704 Use more aggressive caching for accesses to the stack. This improves
3705 performance of remote debugging (particularly backtraces) without
3706 affecting correctness.
3708 set interactive-mode (on|off|auto)
3709 show interactive-mode
3710 Control whether GDB runs in interactive mode (on) or not (off).
3711 When in interactive mode, GDB waits for the user to answer all
3712 queries. Otherwise, GDB does not wait and assumes the default
3713 answer. When set to auto (the default), GDB determines which
3714 mode to use based on the stdin settings.
3719 For program forks, this is replaced by the new more generic `info
3720 inferiors' command. To list checkpoints, you can still use the
3721 `info checkpoints' command, which was an alias for the `info forks'
3725 Replaced by the new `inferior' command. To switch between
3726 checkpoints, you can still use the `restart' command, which was an
3727 alias for the `fork' command.
3730 This is removed, since some targets don't have a notion of
3731 processes. To switch between processes, you can still use the
3732 `inferior' command using GDB's own inferior number.
3735 For program forks, this is replaced by the new more generic `kill
3736 inferior' command. To delete a checkpoint, you can still use the
3737 `delete checkpoint' command, which was an alias for the `delete
3741 For program forks, this is replaced by the new more generic `detach
3742 inferior' command. To detach a checkpoint, you can still use the
3743 `detach checkpoint' command, which was an alias for the `detach
3746 * New native configurations
3748 x86/x86_64 Darwin i[34567]86-*-darwin*
3750 x86_64 MinGW x86_64-*-mingw*
3754 Lattice Mico32 lm32-*
3755 x86 DICOS i[34567]86-*-dicos*
3756 x86_64 DICOS x86_64-*-dicos*
3759 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3760 (mingw32ce) debugging.
3766 These commands were actually not implemented on any target.
3768 *** Changes in GDB 6.8
3770 * New native configurations
3772 NetBSD/hppa hppa*-*netbsd*
3773 Xtensa GNU/Linux xtensa*-*-linux*
3777 NetBSD/hppa hppa*-*-netbsd*
3778 Xtensa GNU/Lunux xtensa*-*-linux*
3780 * Change in command line behavior -- corefiles vs. process ids.
3782 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3783 attaching to process NUMBER fails, GDB no longer attempts to open a
3784 core file named NUMBER. Attaching to a program using the -c option
3785 is no longer supported. Instead, use the '-p' or '--pid' options.
3787 * GDB can now be built as a native debugger for debugging Windows x86
3788 (mingw32) Portable Executable (PE) programs.
3790 * Pending breakpoints no longer change their number when their address
3793 * GDB now supports breakpoints with multiple locations,
3794 including breakpoints on C++ constructors, inside C++ templates,
3795 and in inlined functions.
3797 * GDB's ability to debug optimized code has been improved. GDB more
3798 accurately identifies function bodies and lexical blocks that occupy
3799 more than one contiguous range of addresses.
3801 * Target descriptions can now describe registers for PowerPC.
3803 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3804 registers on PowerPC targets.
3806 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3807 targets even when the libthread_db library is not available.
3809 * The GDB remote stub, gdbserver, now supports the new file transfer
3810 commands (remote put, remote get, and remote delete).
3812 * The GDB remote stub, gdbserver, now supports run and attach in
3813 extended-remote mode.
3815 * hppa*64*-*-hpux11* target broken
3816 The debugger is unable to start a program and fails with the following
3817 error: "Error trying to get information about dynamic linker".
3818 The gdb-6.7 release is also affected.
3820 * GDB now supports the --enable-targets= configure option to allow
3821 building a single GDB executable that supports multiple remote
3822 target architectures.
3824 * GDB now supports debugging C and C++ programs which use the
3825 Decimal Floating Point extension. In addition, the PowerPC target
3826 now has a set of pseudo-registers to inspect decimal float values
3827 stored in two consecutive float registers.
3829 * The -break-insert MI command can optionally create pending
3832 * Improved support for debugging Ada
3833 Many improvements to the Ada language support have been made. These
3835 - Better support for Ada2005 interface types
3836 - Improved handling of arrays and slices in general
3837 - Better support for Taft-amendment types
3838 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3840 - Improved command completion in Ada
3843 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3848 set print frame-arguments (all|scalars|none)
3849 show print frame-arguments
3850 The value of this variable can be changed to control which argument
3851 values should be printed by the debugger when displaying a frame.
3856 Transfer files to and from a remote target, and delete remote files.
3863 Transfer files to and from a remote target, and delete remote files.
3865 * New remote packets
3872 Open, close, read, write, and delete files on the remote system.
3875 Attach to an existing process on the remote system, in extended-remote
3879 Run a new process on the remote system, in extended-remote mode.
3881 *** Changes in GDB 6.7
3883 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3884 bfd, libiberty and opcodes, as revealed by static analysis donated by
3885 Coverity, Inc. (http://scan.coverity.com).
3887 * When looking up multiply-defined global symbols, GDB will now prefer the
3888 symbol definition in the current shared library if it was built using the
3889 -Bsymbolic linker option.
3891 * When the Text User Interface (TUI) is not configured, GDB will now
3892 recognize the -tui command-line option and print a message that the TUI
3895 * The GDB remote stub, gdbserver, now has lower overhead for high
3896 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3898 * GDB for MIPS targets now autodetects whether a remote target provides
3899 32-bit or 64-bit register values.
3901 * Support for C++ member pointers has been improved.
3903 * GDB now understands XML target descriptions, which specify the
3904 target's overall architecture. GDB can read a description from
3905 a local file or over the remote serial protocol.
3907 * Vectors of single-byte data use a new integer type which is not
3908 automatically displayed as character or string data.
3910 * The /s format now works with the print command. It displays
3911 arrays of single-byte integers and pointers to single-byte integers
3914 * Target descriptions can now describe target-specific registers,
3915 for architectures which have implemented the support (currently
3916 only ARM, M68K, and MIPS).
3918 * GDB and the GDB remote stub, gdbserver, now support the XScale
3921 * The GDB remote stub, gdbserver, has been updated to support
3922 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3923 has been rewritten to use the standard GDB remote protocol.
3925 * GDB can now step into C++ functions which are called through thunks.
3927 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3929 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3930 layout. It also supports a TextSeg= and DataSeg= response when only
3931 segment base addresses (rather than offsets) are available.
3933 * The /i format now outputs any trailing branch delay slot instructions
3934 immediately following the last instruction within the count specified.
3936 * The GDB remote protocol "T" stop reply packet now supports a
3937 "library" response. Combined with the new "qXfer:libraries:read"
3938 packet, this response allows GDB to debug shared libraries on targets
3939 where the operating system manages the list of loaded libraries (e.g.
3940 Windows and SymbianOS).
3942 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3943 (DLLs) on Windows and Windows CE targets.
3945 * GDB now supports a faster verification that a .debug file matches its binary
3946 according to its build-id signature, if the signature is present.
3952 Enable or disable hardware flow control (RTS/CTS) on the serial port
3953 when debugging using remote targets.
3955 set mem inaccessible-by-default
3956 show mem inaccessible-by-default
3957 If the target supplies a memory map, for instance via the remote
3958 protocol's "qXfer:memory-map:read" packet, setting this variable
3959 prevents GDB from accessing memory outside the memory map. This
3960 is useful for targets with memory mapped registers or which react
3961 badly to accesses of unmapped address space.
3963 set breakpoint auto-hw
3964 show breakpoint auto-hw
3965 If the target supplies a memory map, for instance via the remote
3966 protocol's "qXfer:memory-map:read" packet, setting this variable
3967 lets GDB use hardware breakpoints automatically for memory regions
3968 where it can not use software breakpoints. This covers both the
3969 "break" command and internal breakpoints used for other commands
3970 including "next" and "finish".
3973 catch exception unhandled
3974 Stop the program execution when Ada exceptions are raised.
3977 Stop the program execution when an Ada assertion failed.
3981 Set an alternate system root for target files. This is a more
3982 general version of "set solib-absolute-prefix", which is now
3983 an alias to "set sysroot".
3986 Provide extended SPU facility status information. This set of
3987 commands is available only when debugging the Cell/B.E. SPU
3990 * New native configurations
3992 OpenBSD/sh sh*-*openbsd*
3995 unset tdesc filename
3997 Use the specified local file as an XML target description, and do
3998 not query the target for its built-in description.
4002 OpenBSD/sh sh*-*-openbsd*
4003 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4004 Toshiba Media Processor mep-elf
4006 * New remote packets
4009 Ignore the specified signals; pass them directly to the debugged program
4010 without stopping other threads or reporting them to GDB.
4012 qXfer:features:read:
4013 Read an XML target description from the target, which describes its
4018 Read or write contents of an spufs file on the target system. These
4019 packets are available only on the Cell/B.E. SPU architecture.
4021 qXfer:libraries:read:
4022 Report the loaded shared libraries. Combined with new "T" packet
4023 response, this packet allows GDB to debug shared libraries on
4024 targets where the operating system manages the list of loaded
4025 libraries (e.g. Windows and SymbianOS).
4029 Support for these obsolete configurations has been removed.
4037 i[34567]86-*-lynxos*
4038 i[34567]86-*-netware*
4039 i[34567]86-*-sco3.2v5*
4040 i[34567]86-*-sco3.2v4*
4042 i[34567]86-*-sysv4.2*
4045 i[34567]86-*-unixware2*
4046 i[34567]86-*-unixware*
4055 * Other removed features
4062 Various m68k-only ROM monitors.
4069 Various Renesas ROM monitors and debugging interfaces for SH and
4074 Support for a Macraigor serial interface to on-chip debugging.
4075 GDB does not directly support the newer parallel or USB
4080 A debug information format. The predecessor to DWARF 2 and
4081 DWARF 3, which are still supported.
4083 Support for the HP aCC compiler on HP-UX/PA-RISC
4085 SOM-encapsulated symbolic debugging information, automatic
4086 invocation of pxdb, and the aCC custom C++ ABI. This does not
4087 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4088 with aCC can still be debugged on an assembly level.
4090 MIPS ".pdr" sections
4092 A MIPS-specific format used to describe stack frame layout
4093 in debugging information.
4097 GDB could work with an older version of Guile to debug
4098 the interpreter and Scheme programs running in it.
4100 set mips stack-arg-size
4101 set mips saved-gpreg-size
4103 Use "set mips abi" to control parameter passing for MIPS.
4105 *** Changes in GDB 6.6
4110 Cell Broadband Engine SPU spu-elf
4112 * GDB can now be configured as a cross-debugger targeting native Windows
4113 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4114 running on a Windows system over TCP/IP to debug Windows programs.
4116 * The GDB remote stub, gdbserver, has been updated to support Windows and
4117 Cygwin debugging. Both single-threaded and multi-threaded programs are
4120 * The "set trust-readonly-sections" command works again. This command was
4121 broken in GDB 6.3, 6.4, and 6.5.
4123 * The "load" command now supports writing to flash memory, if the remote
4124 stub provides the required support.
4126 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4127 longer requires symbolic debug information (e.g. DWARF-2).
4132 unset substitute-path
4133 show substitute-path
4134 Manage a list of substitution rules that GDB uses to rewrite the name
4135 of the directories where the sources are located. This can be useful
4136 for instance when the sources were moved to a different location
4137 between compilation and debugging.
4141 Print each CLI command as it is executed. Each command is prefixed with
4142 a number of `+' symbols representing the nesting depth.
4143 The source command now has a `-v' option to enable the same feature.
4147 The ARM Demon monitor support (RDP protocol, "target rdp").
4149 Kernel Object Display, an embedded debugging feature which only worked with
4150 an obsolete version of Cisco IOS.
4152 The 'set download-write-size' and 'show download-write-size' commands.
4154 * New remote packets
4157 Tell a stub about GDB client features, and request remote target features.
4158 The first feature implemented is PacketSize, which allows the target to
4159 specify the size of packets it can handle - to minimize the number of
4160 packets required and improve performance when connected to a remote
4164 Fetch an OS auxilliary vector from the remote stub. This packet is a
4165 more efficient replacement for qPart:auxv:read.
4167 qXfer:memory-map:read:
4168 Fetch a memory map from the remote stub, including information about
4169 RAM, ROM, and flash memory devices.
4174 Erase and program a flash memory device.
4176 * Removed remote packets
4179 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4180 used it, and only gdbserver implemented it.
4182 *** Changes in GDB 6.5
4186 Renesas M32C/M16C m32c-elf
4188 Morpho Technologies ms1 ms1-elf
4192 init-if-undefined Initialize a convenience variable, but
4193 only if it doesn't already have a value.
4195 The following commands are presently only implemented for native GNU/Linux:
4197 checkpoint Save a snapshot of the program state.
4199 restart <n> Return the program state to a
4200 previously saved state.
4202 info checkpoints List currently saved checkpoints.
4204 delete-checkpoint <n> Delete a previously saved checkpoint.
4206 set|show detach-on-fork Tell gdb whether to detach from a newly
4207 forked process, or to keep debugging it.
4209 info forks List forks of the user program that
4210 are available to be debugged.
4212 fork <n> Switch to debugging one of several
4213 forks of the user program that are
4214 available to be debugged.
4216 delete-fork <n> Delete a fork from the list of forks
4217 that are available to be debugged (and
4218 kill the forked process).
4220 detach-fork <n> Delete a fork from the list of forks
4221 that are available to be debugged (and
4222 allow the process to continue).
4226 Morpho Technologies ms2 ms1-elf
4228 * Improved Windows host support
4230 GDB now builds as a cross debugger hosted on i686-mingw32, including
4231 native console support, and remote communications using either
4232 network sockets or serial ports.
4234 * Improved Modula-2 language support
4236 GDB can now print most types in the Modula-2 syntax. This includes:
4237 basic types, set types, record types, enumerated types, range types,
4238 pointer types and ARRAY types. Procedure var parameters are correctly
4239 printed and hexadecimal addresses and character constants are also
4240 written in the Modula-2 syntax. Best results can be obtained by using
4241 GNU Modula-2 together with the -gdwarf-2 command line option.
4245 The ARM rdi-share module.
4247 The Netware NLM debug server.
4249 *** Changes in GDB 6.4
4251 * New native configurations
4253 OpenBSD/arm arm*-*-openbsd*
4254 OpenBSD/mips64 mips64-*-openbsd*
4258 Morpho Technologies ms1 ms1-elf
4260 * New command line options
4262 --batch-silent As for --batch, but totally silent.
4263 --return-child-result The debugger will exist with the same value
4264 the child (debugged) program exited with.
4265 --eval-command COMMAND, -ex COMMAND
4266 Execute a single GDB CLI command. This may be
4267 specified multiple times and in conjunction
4268 with the --command (-x) option.
4270 * Deprecated commands removed
4272 The following commands, that were deprecated in 2000, have been
4276 set|show arm disassembly-flavor set|show arm disassembler
4277 othernames set arm disassembler
4278 set|show remotedebug set|show debug remote
4279 set|show archdebug set|show debug arch
4280 set|show eventdebug set|show debug event
4283 * New BSD user-level threads support
4285 It is now possible to debug programs using the user-level threads
4286 library on OpenBSD and FreeBSD. Currently supported (target)
4289 FreeBSD/amd64 x86_64-*-freebsd*
4290 FreeBSD/i386 i386-*-freebsd*
4291 OpenBSD/i386 i386-*-openbsd*
4293 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4294 are not yet supported.
4296 * New support for Matsushita MN10300 w/sim added
4297 (Work in progress). mn10300-elf.
4299 * REMOVED configurations and files
4301 VxWorks and the XDR protocol *-*-vxworks
4302 Motorola MCORE mcore-*-*
4303 National Semiconductor NS32000 ns32k-*-*
4305 * New "set print array-indexes" command
4307 After turning this setting "on", GDB prints the index of each element
4308 when displaying arrays. The default is "off" to preserve the previous
4311 * VAX floating point support
4313 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4315 * User-defined command support
4317 In addition to using $arg0..$arg9 for argument passing, it is now possible
4318 to use $argc to determine now many arguments have been passed. See the
4319 section on user-defined commands in the user manual for more information.
4321 *** Changes in GDB 6.3:
4323 * New command line option
4325 GDB now accepts -l followed by a number to set the timeout for remote
4328 * GDB works with GCC -feliminate-dwarf2-dups
4330 GDB now supports a more compact representation of DWARF-2 debug
4331 information using DW_FORM_ref_addr references. These are produced
4332 by GCC with the option -feliminate-dwarf2-dups and also by some
4333 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4334 to use -feliminate-dwarf2-dups.
4336 * Internationalization
4338 When supported by the host system, GDB will be built with
4339 internationalization (libintl). The task of marking up the sources is
4340 continued, we're looking forward to our first translation.
4344 Initial support for debugging programs compiled with the GNAT
4345 implementation of the Ada programming language has been integrated
4346 into GDB. In this release, support is limited to expression evaluation.
4348 * New native configurations
4350 GNU/Linux/m32r m32r-*-linux-gnu
4354 GDB's remote protocol now includes support for the 'p' packet. This
4355 packet is used to fetch individual registers from a remote inferior.
4357 * END-OF-LIFE registers[] compatibility module
4359 GDB's internal register infrastructure has been completely rewritten.
4360 The new infrastructure making possible the implementation of key new
4361 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4364 GDB 6.3 will be the last release to include the the registers[]
4365 compatibility module that allowed out-of-date configurations to
4366 continue to work. This change directly impacts the following
4376 powerpc bdm protocol
4378 Unless there is activity to revive these configurations, they will be
4379 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4381 * OBSOLETE configurations and files
4383 Configurations that have been declared obsolete in this release have
4384 been commented out. Unless there is activity to revive these
4385 configurations, the next release of GDB will have their sources
4386 permanently REMOVED.
4395 *** Changes in GDB 6.2.1:
4397 * MIPS `break main; run' gave an heuristic-fence-post warning
4399 When attempting to run even a simple program, a warning about
4400 heuristic-fence-post being hit would be reported. This problem has
4403 * MIPS IRIX 'long double' crashed GDB
4405 When examining a long double variable, GDB would get a segmentation
4406 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4407 IRIX long double values).
4411 A bug in the VAX stack code was causing problems with the "next"
4412 command. This problem has been fixed.
4414 *** Changes in GDB 6.2:
4416 * Fix for ``many threads''
4418 On GNU/Linux systems that use the NPTL threads library, a program
4419 rapidly creating and deleting threads would confuse GDB leading to the
4422 ptrace: No such process.
4423 thread_db_get_info: cannot get thread info: generic error
4425 This problem has been fixed.
4427 * "-async" and "-noasync" options removed.
4429 Support for the broken "-noasync" option has been removed (it caused
4432 * New ``start'' command.
4434 This command runs the program until the begining of the main procedure.
4436 * New BSD Kernel Data Access Library (libkvm) interface
4438 Using ``target kvm'' it is now possible to debug kernel core dumps and
4439 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4440 platforms. Currently supported (native-only) configurations are:
4442 FreeBSD/amd64 x86_64-*-freebsd*
4443 FreeBSD/i386 i?86-*-freebsd*
4444 NetBSD/i386 i?86-*-netbsd*
4445 NetBSD/m68k m68*-*-netbsd*
4446 NetBSD/sparc sparc-*-netbsd*
4447 OpenBSD/amd64 x86_64-*-openbsd*
4448 OpenBSD/i386 i?86-*-openbsd*
4449 OpenBSD/m68k m68*-openbsd*
4450 OpenBSD/sparc sparc-*-openbsd*
4452 * Signal trampoline code overhauled
4454 Many generic problems with GDB's signal handling code have been fixed.
4455 These include: backtraces through non-contiguous stacks; recognition
4456 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4457 call; backtrace through a signal trampoline; step into and out of
4458 signal handlers; and single-stepping in the signal trampoline.
4460 Please note that kernel bugs are a limiting factor here. These
4461 features have been shown to work on an s390 GNU/Linux system that
4462 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4464 * Cygwin support for DWARF 2 added.
4466 * New native configurations
4468 GNU/Linux/hppa hppa*-*-linux*
4469 OpenBSD/hppa hppa*-*-openbsd*
4470 OpenBSD/m68k m68*-*-openbsd*
4471 OpenBSD/m88k m88*-*-openbsd*
4472 OpenBSD/powerpc powerpc-*-openbsd*
4473 NetBSD/vax vax-*-netbsd*
4474 OpenBSD/vax vax-*-openbsd*
4476 * END-OF-LIFE frame compatibility module
4478 GDB's internal frame infrastructure has been completely rewritten.
4479 The new infrastructure making it possible to support key new features
4480 including DWARF 2 Call Frame Information. To aid in the task of
4481 migrating old configurations to this new infrastructure, a
4482 compatibility module, that allowed old configurations to continue to
4483 work, was also included.
4485 GDB 6.2 will be the last release to include this frame compatibility
4486 module. This change directly impacts the following configurations:
4496 Unless there is activity to revive these configurations, they will be
4497 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4499 * REMOVED configurations and files
4501 Sun 3, running SunOS 3 m68*-*-sunos3*
4502 Sun 3, running SunOS 4 m68*-*-sunos4*
4503 Sun 2, running SunOS 3 m68000-*-sunos3*
4504 Sun 2, running SunOS 4 m68000-*-sunos4*
4505 Motorola 680x0 running LynxOS m68*-*-lynxos*
4506 AT&T 3b1/Unix pc m68*-att-*
4507 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4508 decstation mips-dec-* mips-little-*
4509 riscos mips-*-riscos* mips-*-sysv*
4510 sonymips mips-sony-*
4511 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4513 *** Changes in GDB 6.1.1:
4515 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4517 The TUI (Text-mode User Interface) is now built as part of a default
4518 GDB configuration. It is enabled by either selecting the TUI with the
4519 command line option "-i=tui" or by running the separate "gdbtui"
4520 program. For more information on the TUI, see the manual "Debugging
4523 * Pending breakpoint support (also included in GDB 6.1)
4525 Support has been added to allow you to specify breakpoints in shared
4526 libraries that have not yet been loaded. If a breakpoint location
4527 cannot be found, and the "breakpoint pending" option is set to auto,
4528 GDB queries you if you wish to make the breakpoint pending on a future
4529 shared-library load. If and when GDB resolves the breakpoint symbol,
4530 the pending breakpoint is removed as one or more regular breakpoints
4533 Pending breakpoints are very useful for GCJ Java debugging.
4535 * Fixed ISO-C build problems
4537 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4538 non ISO-C code that stopped them being built using a more strict ISO-C
4539 compiler (e.g., IBM's C compiler).
4541 * Fixed build problem on IRIX 5
4543 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4544 wasn't able to compile compile on an IRIX 5 system.
4546 * Added execute permission to gdb/gdbserver/configure
4548 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4549 permission. This bug would cause configure to fail on a number of
4550 systems (Solaris, IRIX). Ref: server/519.
4552 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4554 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4555 has been updated to use constant array sizes.
4557 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4559 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4560 its generated DWARF Call Frame Info. This encoding was causing GDB to
4561 panic, that panic has been fixed. Ref: gdb/1628.
4563 * Fixed a problem when examining parameters in shared library code.
4565 When examining parameters in optimized shared library code generated
4566 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4567 not available''. GDB now correctly displays the variable's value.
4569 *** Changes in GDB 6.1:
4571 * Removed --with-mmalloc
4573 Support for the mmalloc memory manager has been removed, as it
4574 conflicted with the internal gdb byte cache.
4576 * Changes in AMD64 configurations
4578 The AMD64 target now includes the %cs and %ss registers. As a result
4579 the AMD64 remote protocol has changed; this affects the floating-point
4580 and SSE registers. If you rely on those registers for your debugging,
4581 you should upgrade gdbserver on the remote side.
4583 * Revised SPARC target
4585 The SPARC target has been completely revised, incorporating the
4586 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4587 support for LynxOS and SunOS 4 has been dropped. Calling functions
4588 from within GDB on operating systems with a non-executable stack
4589 (Solaris, OpenBSD) now works.
4593 GDB has a new C++ demangler which does a better job on the mangled
4594 names generated by current versions of g++. It also runs faster, so
4595 with this and other changes gdb should now start faster on large C++
4598 * DWARF 2 Location Expressions
4600 GDB support for location expressions has been extended to support function
4601 arguments and frame bases. Older versions of GDB could crash when they
4604 * C++ nested types and namespaces
4606 GDB's support for nested types and namespaces in C++ has been
4607 improved, especially if you use the DWARF 2 debugging format. (This
4608 is the default for recent versions of GCC on most platforms.)
4609 Specifically, if you have a class "Inner" defined within a class or
4610 namespace "Outer", then GDB realizes that the class's name is
4611 "Outer::Inner", not simply "Inner". This should greatly reduce the
4612 frequency of complaints about not finding RTTI symbols. In addition,
4613 if you are stopped at inside of a function defined within a namespace,
4614 GDB modifies its name lookup accordingly.
4616 * New native configurations
4618 NetBSD/amd64 x86_64-*-netbsd*
4619 OpenBSD/amd64 x86_64-*-openbsd*
4620 OpenBSD/alpha alpha*-*-openbsd*
4621 OpenBSD/sparc sparc-*-openbsd*
4622 OpenBSD/sparc64 sparc64-*-openbsd*
4624 * New debugging protocols
4626 M32R with SDI protocol m32r-*-elf*
4628 * "set prompt-escape-char" command deleted.
4630 The command "set prompt-escape-char" has been deleted. This command,
4631 and its very obscure effet on GDB's prompt, was never documented,
4632 tested, nor mentioned in the NEWS file.
4634 * OBSOLETE configurations and files
4636 Configurations that have been declared obsolete in this release have
4637 been commented out. Unless there is activity to revive these
4638 configurations, the next release of GDB will have their sources
4639 permanently REMOVED.
4641 Sun 3, running SunOS 3 m68*-*-sunos3*
4642 Sun 3, running SunOS 4 m68*-*-sunos4*
4643 Sun 2, running SunOS 3 m68000-*-sunos3*
4644 Sun 2, running SunOS 4 m68000-*-sunos4*
4645 Motorola 680x0 running LynxOS m68*-*-lynxos*
4646 AT&T 3b1/Unix pc m68*-att-*
4647 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4648 decstation mips-dec-* mips-little-*
4649 riscos mips-*-riscos* mips-*-sysv*
4650 sonymips mips-sony-*
4651 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4653 * REMOVED configurations and files
4655 SGI Irix-4.x mips-sgi-irix4 or iris4
4656 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4657 Z8000 simulator z8k-zilog-none or z8ksim
4658 Matsushita MN10200 w/simulator mn10200-*-*
4659 H8/500 simulator h8500-hitachi-hms or h8500hms
4660 HP/PA running BSD hppa*-*-bsd*
4661 HP/PA running OSF/1 hppa*-*-osf*
4662 HP/PA Pro target hppa*-*-pro*
4663 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4664 386BSD i[3456]86-*-bsd*
4665 Sequent family i[3456]86-sequent-sysv4*
4666 i[3456]86-sequent-sysv*
4667 i[3456]86-sequent-bsd*
4668 SPARC running LynxOS sparc-*-lynxos*
4669 SPARC running SunOS 4 sparc-*-sunos4*
4670 Tsqware Sparclet sparclet-*-*
4671 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4673 *** Changes in GDB 6.0:
4677 Support for debugging the Objective-C programming language has been
4678 integrated into GDB.
4680 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4682 DWARF 2's Call Frame Information makes available compiler generated
4683 information that more exactly describes the program's run-time stack.
4684 By using this information, GDB is able to provide more robust stack
4687 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4688 have been updated to use a new backtrace mechanism which includes
4689 DWARF 2 CFI support.
4693 GDB's remote protocol has been extended to include support for hosted
4694 file I/O (where the remote target uses GDB's file system). See GDB's
4695 remote protocol documentation for details.
4697 * All targets using the new architecture framework.
4699 All of GDB's targets have been updated to use the new internal
4700 architecture framework. The way is now open for future GDB releases
4701 to include cross-architecture native debugging support (i386 on amd64,
4704 * GNU/Linux's Thread Local Storage (TLS)
4706 GDB now includes support for for the GNU/Linux implementation of
4707 per-thread variables.
4709 * GNU/Linux's Native POSIX Thread Library (NPTL)
4711 GDB's thread code has been updated to work with either the new
4712 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4714 * Separate debug info.
4716 GDB, in conjunction with BINUTILS, now supports a mechanism for
4717 automatically loading debug information from a separate file. Instead
4718 of shipping full debug and non-debug versions of system libraries,
4719 system integrators can now instead ship just the stripped libraries
4720 and optional debug files.
4722 * DWARF 2 Location Expressions
4724 DWARF 2 Location Expressions allow the compiler to more completely
4725 describe the location of variables (even in optimized code) to the
4728 GDB now includes preliminary support for location expressions (support
4729 for DW_OP_piece is still missing).
4733 A number of long standing bugs that caused GDB to die while starting a
4734 Java application have been fixed. GDB's Java support is now
4735 considered "useable".
4737 * GNU/Linux support for fork, vfork, and exec.
4739 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4740 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4743 * GDB supports logging output to a file
4745 There are two new commands, "set logging" and "show logging", which can be
4746 used to capture GDB's output to a file.
4748 * The meaning of "detach" has changed for gdbserver
4750 The "detach" command will now resume the application, as documented. To
4751 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4754 * d10v, m68hc11 `regs' command deprecated
4756 The `info registers' command has been updated so that it displays the
4757 registers using a format identical to the old `regs' command.
4761 A new command, "maint set profile on/off", has been added. This command can
4762 be used to enable or disable profiling while running GDB, to profile a
4763 session or a set of commands. In addition there is a new configure switch,
4764 "--enable-profiling", which will cause GDB to be compiled with profiling
4765 data, for more informative profiling results.
4767 * Default MI syntax changed to "mi2".
4769 The default MI (machine interface) syntax, enabled by the command line
4770 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4771 "mi1", can be enabled by specifying the option "-i=mi1".
4773 Support for the original "mi0" syntax (included in GDB 5.0) has been
4776 Fix for gdb/192: removed extraneous space when displaying frame level.
4777 Fix for gdb/672: update changelist is now output in mi list format.
4778 Fix for gdb/702: a -var-assign that updates the value now shows up
4779 in a subsequent -var-update.
4781 * New native configurations.
4783 FreeBSD/amd64 x86_64-*-freebsd*
4785 * Multi-arched targets.
4787 HP/PA HPUX11 hppa*-*-hpux*
4788 Renesas M32R/D w/simulator m32r-*-elf*
4790 * OBSOLETE configurations and files
4792 Configurations that have been declared obsolete in this release have
4793 been commented out. Unless there is activity to revive these
4794 configurations, the next release of GDB will have their sources
4795 permanently REMOVED.
4797 Z8000 simulator z8k-zilog-none or z8ksim
4798 Matsushita MN10200 w/simulator mn10200-*-*
4799 H8/500 simulator h8500-hitachi-hms or h8500hms
4800 HP/PA running BSD hppa*-*-bsd*
4801 HP/PA running OSF/1 hppa*-*-osf*
4802 HP/PA Pro target hppa*-*-pro*
4803 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4804 Sequent family i[3456]86-sequent-sysv4*
4805 i[3456]86-sequent-sysv*
4806 i[3456]86-sequent-bsd*
4807 Tsqware Sparclet sparclet-*-*
4808 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4810 * REMOVED configurations and files
4813 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4814 IBM AIX PS/2 i[3456]86-*-aix
4815 i386 running Mach 3.0 i[3456]86-*-mach3*
4816 i386 running Mach i[3456]86-*-mach*
4817 i386 running OSF/1 i[3456]86-*osf1mk*
4818 HP/Apollo 68k Family m68*-apollo*-sysv*,
4820 m68*-hp-bsd*, m68*-hp-hpux*
4821 Argonaut Risc Chip (ARC) arc-*-*
4822 Mitsubishi D30V d30v-*-*
4823 Fujitsu FR30 fr30-*-elf*
4824 OS/9000 i[34]86-*-os9k
4825 I960 with MON960 i960-*-coff
4827 * MIPS $fp behavior changed
4829 The convenience variable $fp, for the MIPS, now consistently returns
4830 the address of the current frame's base. Previously, depending on the
4831 context, $fp could refer to either $sp or the current frame's base
4832 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4833 The GNU Source-Level Debugger''.
4835 *** Changes in GDB 5.3:
4837 * GNU/Linux shared library multi-threaded performance improved.
4839 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4840 `/proc', in preference to `ptrace' for memory reads. This may result
4841 in an improvement in the start-up time of multi-threaded, shared
4842 library applications when run under GDB. One GDB user writes: ``loads
4843 shared libs like mad''.
4845 * ``gdbserver'' now supports multi-threaded applications on some targets
4847 Support for debugging multi-threaded applications which use
4848 the GNU/Linux LinuxThreads package has been added for
4849 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4850 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4852 * GDB now supports C/C++ preprocessor macros.
4854 GDB now expands preprocessor macro invocations in C/C++ expressions,
4855 and provides various commands for showing macro definitions and how
4858 The new command `macro expand EXPRESSION' expands any macro
4859 invocations in expression, and shows the result.
4861 The new command `show macro MACRO-NAME' shows the definition of the
4862 macro named MACRO-NAME, and where it was defined.
4864 Most compilers don't include information about macros in the debugging
4865 information by default. In GCC 3.1, for example, you need to compile
4866 your program with the options `-gdwarf-2 -g3'. If the macro
4867 information is present in the executable, GDB will read it.
4869 * Multi-arched targets.
4871 DEC Alpha (partial) alpha*-*-*
4872 DEC VAX (partial) vax-*-*
4874 National Semiconductor NS32000 (partial) ns32k-*-*
4875 Motorola 68000 (partial) m68k-*-*
4876 Motorola MCORE mcore-*-*
4880 Fujitsu FRV architecture added by Red Hat frv*-*-*
4883 * New native configurations
4885 Alpha NetBSD alpha*-*-netbsd*
4886 SH NetBSD sh*-*-netbsdelf*
4887 MIPS NetBSD mips*-*-netbsd*
4888 UltraSPARC NetBSD sparc64-*-netbsd*
4890 * OBSOLETE configurations and files
4892 Configurations that have been declared obsolete in this release have
4893 been commented out. Unless there is activity to revive these
4894 configurations, the next release of GDB will have their sources
4895 permanently REMOVED.
4897 Mitsubishi D30V d30v-*-*
4898 OS/9000 i[34]86-*-os9k
4899 IBM AIX PS/2 i[3456]86-*-aix
4900 Fujitsu FR30 fr30-*-elf*
4901 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4902 Argonaut Risc Chip (ARC) arc-*-*
4903 i386 running Mach 3.0 i[3456]86-*-mach3*
4904 i386 running Mach i[3456]86-*-mach*
4905 i386 running OSF/1 i[3456]86-*osf1mk*
4906 HP/Apollo 68k Family m68*-apollo*-sysv*,
4908 m68*-hp-bsd*, m68*-hp-hpux*
4909 I960 with MON960 i960-*-coff
4911 * OBSOLETE languages
4913 CHILL, a Pascal like language used by telecommunications companies.
4915 * REMOVED configurations and files
4917 AMD 29k family via UDI a29k-amd-udi, udi29k
4918 A29K VxWorks a29k-*-vxworks
4919 AMD 29000 embedded, using EBMON a29k-none-none
4920 AMD 29000 embedded with COFF a29k-none-coff
4921 AMD 29000 embedded with a.out a29k-none-aout
4923 testsuite/gdb.hp/gdb.threads-hp/ directory
4925 * New command "set max-user-call-depth <nnn>"
4927 This command allows the user to limit the call depth of user-defined
4928 commands. The default is 1024.
4930 * Changes in FreeBSD/i386 native debugging.
4932 Support for the "generate-core-file" has been added.
4934 * New commands "dump", "append", and "restore".
4936 These commands allow data to be copied from target memory
4937 to a bfd-format or binary file (dump and append), and back
4938 from a file into memory (restore).
4940 * Improved "next/step" support on multi-processor Alpha Tru64.
4942 The previous single-step mechanism could cause unpredictable problems,
4943 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4944 of a software single-step mechanism prevents this.
4946 *** Changes in GDB 5.2.1:
4954 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4955 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4956 Fix, by Joel Brobecker imported from mainline.
4958 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4959 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4960 Fix, by Fred Fish, imported from mainline.
4962 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4963 Surprisingly enough, it works now.
4964 By Michal Ludvig, imported from mainline.
4966 i386 hardware watchpoint support:
4967 avoid misses on second run for some targets.
4968 By Pierre Muller, imported from mainline.
4970 *** Changes in GDB 5.2:
4972 * New command "set trust-readonly-sections on[off]".
4974 This command is a hint that tells gdb that read-only sections
4975 really are read-only (ie. that their contents will not change).
4976 In this mode, gdb will go to the object file rather than the
4977 target to read memory from read-only sections (such as ".text").
4978 This can be a significant performance improvement on some
4979 (notably embedded) targets.
4981 * New command "generate-core-file" (or "gcore").
4983 This new gdb command allows the user to drop a core file of the child
4984 process state at any time. So far it's been implemented only for
4985 GNU/Linux and Solaris, but should be relatively easily ported to other
4986 hosts. Argument is core file name (defaults to core.<pid>).
4988 * New command line option
4990 GDB now accepts --pid or -p followed by a process id.
4992 * Change in command line behavior -- corefiles vs. process ids.
4994 There is a subtle behavior in the way in which GDB handles
4995 command line arguments. The first non-flag argument is always
4996 a program to debug, but the second non-flag argument may either
4997 be a corefile or a process id. Previously, GDB would attempt to
4998 open the second argument as a corefile, and if that failed, would
4999 issue a superfluous error message and then attempt to attach it as
5000 a process. Now, if the second argument begins with a non-digit,
5001 it will be treated as a corefile. If it begins with a digit,
5002 GDB will attempt to attach it as a process, and if no such process
5003 is found, will then attempt to open it as a corefile.
5005 * Changes in ARM configurations.
5007 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5008 configuration is fully multi-arch.
5010 * New native configurations
5012 ARM NetBSD arm*-*-netbsd*
5013 x86 OpenBSD i[3456]86-*-openbsd*
5014 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5015 Sparc64 running FreeBSD sparc64-*-freebsd*
5019 Sanyo XStormy16 xstormy16-elf
5021 * OBSOLETE configurations and files
5023 Configurations that have been declared obsolete in this release have
5024 been commented out. Unless there is activity to revive these
5025 configurations, the next release of GDB will have their sources
5026 permanently REMOVED.
5028 AMD 29k family via UDI a29k-amd-udi, udi29k
5029 A29K VxWorks a29k-*-vxworks
5030 AMD 29000 embedded, using EBMON a29k-none-none
5031 AMD 29000 embedded with COFF a29k-none-coff
5032 AMD 29000 embedded with a.out a29k-none-aout
5034 testsuite/gdb.hp/gdb.threads-hp/ directory
5036 * REMOVED configurations and files
5038 TI TMS320C80 tic80-*-*
5040 PowerPC Solaris powerpcle-*-solaris*
5041 PowerPC Windows NT powerpcle-*-cygwin32
5042 PowerPC Netware powerpc-*-netware*
5043 Harris/CXUX m88k m88*-harris-cxux*
5044 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5045 ns32k-utek-sysv* ns32k-utek-*
5046 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5047 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5048 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5049 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5050 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5052 * Changes to command line processing
5054 The new `--args' feature can be used to specify command-line arguments
5055 for the inferior from gdb's command line.
5057 * Changes to key bindings
5059 There is a new `operate-and-get-next' function bound to `C-o'.
5061 *** Changes in GDB 5.1.1
5063 Fix compile problem on DJGPP.
5065 Fix a problem with floating-point registers on the i386 being
5068 Fix to stop GDB crashing on .debug_str debug info.
5070 Numerous documentation fixes.
5072 Numerous testsuite fixes.
5074 *** Changes in GDB 5.1:
5076 * New native configurations
5078 Alpha FreeBSD alpha*-*-freebsd*
5079 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5080 MIPS GNU/Linux mips*-*-linux*
5081 MIPS SGI Irix 6.x mips*-sgi-irix6*
5082 ia64 AIX ia64-*-aix*
5083 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5087 Motorola 68HC11 and 68HC12 m68hc11-elf
5089 UltraSparc running GNU/Linux sparc64-*-linux*
5091 * OBSOLETE configurations and files
5093 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5094 Harris/CXUX m88k m88*-harris-cxux*
5095 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5096 ns32k-utek-sysv* ns32k-utek-*
5097 TI TMS320C80 tic80-*-*
5099 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5100 PowerPC Solaris powerpcle-*-solaris*
5101 PowerPC Windows NT powerpcle-*-cygwin32
5102 PowerPC Netware powerpc-*-netware*
5103 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5104 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5105 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5106 Apple Macintosh (MPW) host N/A
5108 stuff.c (Program to stuff files into a specially prepared space in kdb)
5109 kdb-start.c (Main loop for the standalone kernel debugger)
5111 Configurations that have been declared obsolete in this release have
5112 been commented out. Unless there is activity to revive these
5113 configurations, the next release of GDB will have their sources
5114 permanently REMOVED.
5116 * REMOVED configurations and files
5118 Altos 3068 m68*-altos-*
5119 Convex c1-*-*, c2-*-*
5121 ARM RISCix arm-*-* (as host)
5125 * GDB has been converted to ISO C.
5127 GDB's source code has been converted to ISO C. In particular, the
5128 sources are fully protoized, and rely on standard headers being
5133 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5135 * The MI enabled by default.
5137 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5138 revised and enabled by default. Packages which use GDB as a debugging
5139 engine behind a UI or another front end are encouraged to switch to
5140 using the GDB/MI interface, instead of the old annotations interface
5141 which is now deprecated.
5143 * Support for debugging Pascal programs.
5145 GDB now includes support for debugging Pascal programs. The following
5146 main features are supported:
5148 - Pascal-specific data types such as sets;
5150 - automatic recognition of Pascal sources based on file-name
5153 - Pascal-style display of data types, variables, and functions;
5155 - a Pascal expression parser.
5157 However, some important features are not yet supported.
5159 - Pascal string operations are not supported at all;
5161 - there are some problems with boolean types;
5163 - Pascal type hexadecimal constants are not supported
5164 because they conflict with the internal variables format;
5166 - support for Pascal objects and classes is not full yet;
5168 - unlike Pascal, GDB is case-sensitive for symbol names.
5170 * Changes in completion.
5172 Commands such as `shell', `run' and `set args', which pass arguments
5173 to inferior programs, now complete on file names, similar to what
5174 users expect at the shell prompt.
5176 Commands which accept locations, such as `disassemble', `print',
5177 `breakpoint', `until', etc. now complete on filenames as well as
5178 program symbols. Thus, if you type "break foob TAB", and the source
5179 files linked into the programs include `foobar.c', that file name will
5180 be one of the candidates for completion. However, file names are not
5181 considered for completion after you typed a colon that delimits a file
5182 name from a name of a function in that file, as in "break foo.c:bar".
5184 `set demangle-style' completes on available demangling styles.
5186 * New platform-independent commands:
5188 It is now possible to define a post-hook for a command as well as a
5189 hook that runs before the command. For more details, see the
5190 documentation of `hookpost' in the GDB manual.
5192 * Changes in GNU/Linux native debugging.
5194 Support for debugging multi-threaded programs has been completely
5195 revised for all platforms except m68k and sparc. You can now debug as
5196 many threads as your system allows you to have.
5198 Attach/detach is supported for multi-threaded programs.
5200 Support for SSE registers was added for x86. This doesn't work for
5201 multi-threaded programs though.
5203 * Changes in MIPS configurations.
5205 Multi-arch support is enabled for all MIPS configurations.
5207 GDB can now be built as native debugger on SGI Irix 6.x systems for
5208 debugging n32 executables. (Debugging 64-bit executables is not yet
5211 * Unified support for hardware watchpoints in all x86 configurations.
5213 Most (if not all) native x86 configurations support hardware-assisted
5214 breakpoints and watchpoints in a unified manner. This support
5215 implements debug register sharing between watchpoints, which allows to
5216 put a virtually infinite number of watchpoints on the same address,
5217 and also supports watching regions up to 16 bytes with several debug
5220 The new maintenance command `maintenance show-debug-regs' toggles
5221 debugging print-outs in functions that insert, remove, and test
5222 watchpoints and hardware breakpoints.
5224 * Changes in the DJGPP native configuration.
5226 New command ``info dos sysinfo'' displays assorted information about
5227 the CPU, OS, memory, and DPMI server.
5229 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5230 display information about segment descriptors stored in GDT, LDT, and
5233 New commands ``info dos pde'' and ``info dos pte'' display entries
5234 from Page Directory and Page Tables (for now works with CWSDPMI only).
5235 New command ``info dos address-pte'' displays the Page Table entry for
5236 a given linear address.
5238 GDB can now pass command lines longer than 126 characters to the
5239 program being debugged (requires an update to the libdbg.a library
5240 which is part of the DJGPP development kit).
5242 DWARF2 debug info is now supported.
5244 It is now possible to `step' and `next' through calls to `longjmp'.
5246 * Changes in documentation.
5248 All GDB documentation was converted to GFDL, the GNU Free
5249 Documentation License.
5251 Tracepoints-related commands are now fully documented in the GDB
5254 TUI, the Text-mode User Interface, is now documented in the manual.
5256 Tracepoints-related commands are now fully documented in the GDB
5259 The "GDB Internals" manual now has an index. It also includes
5260 documentation of `ui_out' functions, GDB coding standards, x86
5261 hardware watchpoints, and memory region attributes.
5263 * GDB's version number moved to ``version.in''
5265 The Makefile variable VERSION has been replaced by the file
5266 ``version.in''. People creating GDB distributions should update the
5267 contents of this file.
5271 GUD support is now a standard part of the EMACS distribution.
5273 *** Changes in GDB 5.0:
5275 * Improved support for debugging FP programs on x86 targets
5277 Unified and much-improved support for debugging floating-point
5278 programs on all x86 targets. In particular, ``info float'' now
5279 displays the FP registers in the same format on all x86 targets, with
5280 greater level of detail.
5282 * Improvements and bugfixes in hardware-assisted watchpoints
5284 It is now possible to watch array elements, struct members, and
5285 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5286 on x86 targets no longer erroneously trigger when the address is
5289 * Improvements in the native DJGPP version of GDB
5291 The distribution now includes all the scripts and auxiliary files
5292 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5293 machines ``out of the box''.
5295 The DJGPP version can now debug programs that use signals. It is
5296 possible to catch signals that happened in the debuggee, deliver
5297 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5298 would kill the program being debugged.) Programs that hook hardware
5299 interrupts (keyboard, timer, etc.) can also be debugged.
5301 It is now possible to debug DJGPP programs that redirect their
5302 standard handles or switch them to raw (as opposed to cooked) mode, or
5303 even close them. The command ``run < foo > bar'' works as expected,
5304 and ``info terminal'' reports useful information about the debuggee's
5305 terminal, including raw/cooked mode, redirection, etc.
5307 The DJGPP version now uses termios functions for console I/O, which
5308 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5311 DOS-style file names with drive letters are now fully supported by
5314 It is now possible to debug DJGPP programs that switch their working
5315 directory. It is also possible to rerun the debuggee any number of
5316 times without restarting GDB; thus, you can use the same setup,
5317 breakpoints, etc. for many debugging sessions.
5319 * New native configurations
5321 ARM GNU/Linux arm*-*-linux*
5322 PowerPC GNU/Linux powerpc-*-linux*
5326 Motorola MCore mcore-*-*
5327 x86 VxWorks i[3456]86-*-vxworks*
5328 PowerPC VxWorks powerpc-*-vxworks*
5329 TI TMS320C80 tic80-*-*
5331 * OBSOLETE configurations
5333 Altos 3068 m68*-altos-*
5334 Convex c1-*-*, c2-*-*
5336 ARM RISCix arm-*-* (as host)
5339 Configurations that have been declared obsolete will be commented out,
5340 but the code will be left in place. If there is no activity to revive
5341 these configurations before the next release of GDB, the sources will
5342 be permanently REMOVED.
5344 * Gould support removed
5346 Support for the Gould PowerNode and NP1 has been removed.
5348 * New features for SVR4
5350 On SVR4 native platforms (such as Solaris), if you attach to a process
5351 without first loading a symbol file, GDB will now attempt to locate and
5352 load symbols from the running process's executable file.
5354 * Many C++ enhancements
5356 C++ support has been greatly improved. Overload resolution now works properly
5357 in almost all cases. RTTI support is on the way.
5359 * Remote targets can connect to a sub-program
5361 A popen(3) style serial-device has been added. This device starts a
5362 sub-process (such as a stand-alone simulator) and then communicates
5363 with that. The sub-program to run is specified using the syntax
5364 ``|<program> <args>'' vis:
5366 (gdb) set remotedebug 1
5367 (gdb) target extended-remote |mn10300-elf-sim program-args
5369 * MIPS 64 remote protocol
5371 A long standing bug in the mips64 remote protocol where by GDB
5372 expected certain 32 bit registers (ex SR) to be transfered as 32
5373 instead of 64 bits has been fixed.
5375 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5376 added to provide backward compatibility with older versions of GDB.
5378 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5380 The command ``set remotebinarydownload'' command has been replaced by
5381 ``set remote X-packet''. Other commands in ``set remote'' family
5382 include ``set remote P-packet''.
5384 * Breakpoint commands accept ranges.
5386 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5387 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5388 ``tracepoint passcount'' also accepts a range of tracepoints.
5390 * ``apropos'' command added.
5392 The ``apropos'' command searches through command names and
5393 documentation strings, printing out matches, making it much easier to
5394 try to find a command that does what you are looking for.
5398 A new machine oriented interface (MI) has been added to GDB. This
5399 interface is designed for debug environments running GDB as a separate
5400 process. This is part of the long term libGDB project. See the
5401 "GDB/MI" chapter of the GDB manual for further information. It can be
5402 enabled by configuring with:
5404 .../configure --enable-gdbmi
5406 *** Changes in GDB-4.18:
5408 * New native configurations
5410 HP-UX 10.20 hppa*-*-hpux10.20
5411 HP-UX 11.x hppa*-*-hpux11.0*
5412 M68K GNU/Linux m68*-*-linux*
5416 Fujitsu FR30 fr30-*-elf*
5417 Intel StrongARM strongarm-*-*
5418 Mitsubishi D30V d30v-*-*
5420 * OBSOLETE configurations
5422 Gould PowerNode, NP1 np1-*-*, pn-*-*
5424 Configurations that have been declared obsolete will be commented out,
5425 but the code will be left in place. If there is no activity to revive
5426 these configurations before the next release of GDB, the sources will
5427 be permanently REMOVED.
5431 As a compatibility experiment, GDB's source files buildsym.h and
5432 buildsym.c have been converted to pure standard C, no longer
5433 containing any K&R compatibility code. We believe that all systems in
5434 use today either come with a standard C compiler, or have a GCC port
5435 available. If this is not true, please report the affected
5436 configuration to bug-gdb@gnu.org immediately. See the README file for
5437 information about getting a standard C compiler if you don't have one
5442 GDB now uses readline 2.2.
5444 * set extension-language
5446 You can now control the mapping between filename extensions and source
5447 languages by using the `set extension-language' command. For instance,
5448 you can ask GDB to treat .c files as C++ by saying
5449 set extension-language .c c++
5450 The command `info extensions' lists all of the recognized extensions
5451 and their associated languages.
5453 * Setting processor type for PowerPC and RS/6000
5455 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5456 you can use the `set processor' command to specify what variant of the
5457 PowerPC family you are debugging. The command
5461 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5462 following PowerPC and RS6000 variants:
5464 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5465 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5467 403GC IBM PowerPC 403GC
5468 505 Motorola PowerPC 505
5469 860 Motorola PowerPC 860 or 850
5470 601 Motorola PowerPC 601
5471 602 Motorola PowerPC 602
5472 603 Motorola/IBM PowerPC 603 or 603e
5473 604 Motorola PowerPC 604 or 604e
5474 750 Motorola/IBM PowerPC 750 or 750
5476 At the moment, this command just tells GDB what to name the
5477 special-purpose processor registers. Since almost all the affected
5478 registers are inaccessible to user-level programs, this command is
5479 only useful for remote debugging in its present form.
5483 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5484 more extensive support for HP-UX. Added features include shared
5485 library support, kernel threads and hardware watchpoints for 11.00,
5486 support for HP's ANSI C and C++ compilers, and a compatibility mode
5487 for xdb and dbx commands.
5491 HP's donation includes the new concept of catchpoints, which is a
5492 generalization of the old catch command. On HP-UX, it is now possible
5493 to catch exec, fork, and vfork, as well as library loading.
5495 This means that the existing catch command has changed; its first
5496 argument now specifies the type of catch to be set up. See the
5497 output of "help catch" for a list of catchpoint types.
5499 * Debugging across forks
5501 On HP-UX, you can choose which process to debug when a fork() happens
5506 HP has donated a curses-based terminal user interface (TUI). To get
5507 it, build with --enable-tui. Although this can be enabled for any
5508 configuration, at present it only works for native HP debugging.
5510 * GDB remote protocol additions
5512 A new protocol packet 'X' that writes binary data is now available.
5513 Default behavior is to try 'X', then drop back to 'M' if the stub
5514 fails to respond. The settable variable `remotebinarydownload'
5515 allows explicit control over the use of 'X'.
5517 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5518 full 64-bit address. The command
5520 set remoteaddresssize 32
5522 can be used to revert to the old behaviour. For existing remote stubs
5523 the change should not be noticed, as the additional address information
5526 In order to assist in debugging stubs, you may use the maintenance
5527 command `packet' to send any text string to the stub. For instance,
5529 maint packet heythere
5531 sends the packet "$heythere#<checksum>". Note that it is very easy to
5532 disrupt a debugging session by sending the wrong packet at the wrong
5535 The compare-sections command allows you to compare section data on the
5536 target to what is in the executable file without uploading or
5537 downloading, by comparing CRC checksums.
5539 * Tracing can collect general expressions
5541 You may now collect general expressions at tracepoints. This requires
5542 further additions to the target-side stub; see tracepoint.c and
5543 doc/agentexpr.texi for further details.
5545 * mask-address variable for Mips
5547 For Mips targets, you may control the zeroing of the upper 32 bits of
5548 a 64-bit address by entering `set mask-address on'. This is mainly
5549 of interest to users of embedded R4xxx and R5xxx processors.
5551 * Higher serial baud rates
5553 GDB's serial code now allows you to specify baud rates 57600, 115200,
5554 230400, and 460800 baud. (Note that your host system may not be able
5555 to achieve all of these rates.)
5559 The i960 configuration now includes an initial implementation of a
5560 builtin simulator, contributed by Jim Wilson.
5563 *** Changes in GDB-4.17:
5565 * New native configurations
5567 Alpha GNU/Linux alpha*-*-linux*
5568 Unixware 2.x i[3456]86-unixware2*
5569 Irix 6.x mips*-sgi-irix6*
5570 PowerPC GNU/Linux powerpc-*-linux*
5571 PowerPC Solaris powerpcle-*-solaris*
5572 Sparc GNU/Linux sparc-*-linux*
5573 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5577 Argonaut Risc Chip (ARC) arc-*-*
5578 Hitachi H8/300S h8300*-*-*
5579 Matsushita MN10200 w/simulator mn10200-*-*
5580 Matsushita MN10300 w/simulator mn10300-*-*
5581 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5582 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5583 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5584 Mitsubishi D10V w/simulator d10v-*-*
5585 Mitsubishi M32R/D w/simulator m32r-*-elf*
5586 Tsqware Sparclet sparclet-*-*
5587 NEC V850 w/simulator v850-*-*
5589 * New debugging protocols
5591 ARM with RDI protocol arm*-*-*
5592 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5593 DDB and LSI variants of PMON protocol mips*-*-*
5594 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5595 PowerPC with SDS protocol powerpc{,le}-*-eabi
5596 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5600 All configurations can now understand and use the DWARF 2 debugging
5601 format. The choice is automatic, if the symbol file contains DWARF 2
5606 GDB now includes basic Java language support. This support is
5607 only useful with Java compilers that produce native machine code.
5609 * solib-absolute-prefix and solib-search-path
5611 For SunOS and SVR4 shared libraries, you may now set the prefix for
5612 loading absolute shared library symbol files, and the search path for
5613 locating non-absolute shared library symbol files.
5615 * Live range splitting
5617 GDB can now effectively debug code for which GCC has performed live
5618 range splitting as part of its optimization. See gdb/doc/LRS for
5619 more details on the expected format of the stabs information.
5623 GDB's support for the GNU Hurd, including thread debugging, has been
5624 updated to work with current versions of the Hurd.
5628 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5629 instruction set. ARM GDB automatically detects when Thumb
5630 instructions are in use, and adjusts disassembly and backtracing
5635 GDB's MIPS target configurations now handle the MIP16 16-bit
5640 GDB now includes support for overlays; if an executable has been
5641 linked such that multiple sections are based at the same address, GDB
5642 will decide which section to use for symbolic info. You can choose to
5643 control the decision manually, using overlay commands, or implement
5644 additional target-side support and use "overlay load-target" to bring
5645 in the overlay mapping. Do "help overlay" for more detail.
5649 The command "info symbol <address>" displays information about
5650 the symbol at the specified address.
5654 The standard remote protocol now includes an extension that allows
5655 asynchronous collection and display of trace data. This requires
5656 extensive support in the target-side debugging stub. Tracing mode
5657 includes a new interaction mode in GDB and new commands: see the
5658 file tracepoint.c for more details.
5662 Configurations for embedded MIPS now include a simulator contributed
5663 by Cygnus Solutions. The simulator supports the instruction sets
5664 of most MIPS variants.
5668 Sparc configurations may now include the ERC32 simulator contributed
5669 by the European Space Agency. The simulator is not built into
5670 Sparc targets by default; configure with --enable-sim to include it.
5674 For target configurations that may include multiple variants of a
5675 basic architecture (such as MIPS and SH), you may now set the
5676 architecture explicitly. "set arch" sets, "info arch" lists
5677 the possible architectures.
5679 *** Changes in GDB-4.16:
5681 * New native configurations
5683 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5684 M68K NetBSD m68k-*-netbsd*
5685 PowerPC AIX 4.x powerpc-*-aix*
5686 PowerPC MacOS powerpc-*-macos*
5687 PowerPC Windows NT powerpcle-*-cygwin32
5688 RS/6000 AIX 4.x rs6000-*-aix4*
5692 ARM with RDP protocol arm-*-*
5693 I960 with MON960 i960-*-coff
5694 MIPS VxWorks mips*-*-vxworks*
5695 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5696 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5698 Matra Sparclet sparclet-*-*
5702 The powerpc-eabi configuration now includes the PSIM simulator,
5703 contributed by Andrew Cagney, with assistance from Mike Meissner.
5704 PSIM is a very elaborate model of the PowerPC, including not only
5705 basic instruction set execution, but also details of execution unit
5706 performance and I/O hardware. See sim/ppc/README for more details.
5710 GDB now works with Solaris 2.5.
5712 * Windows 95/NT native
5714 GDB will now work as a native debugger on Windows 95 and Windows NT.
5715 To build it from source, you must use the "gnu-win32" environment,
5716 which uses a DLL to emulate enough of Unix to run the GNU tools.
5717 Further information, binaries, and sources are available at
5718 ftp.cygnus.com, under pub/gnu-win32.
5720 * dont-repeat command
5722 If a user-defined command includes the command `dont-repeat', then the
5723 command will not be repeated if the user just types return. This is
5724 useful if the command is time-consuming to run, so that accidental
5725 extra keystrokes don't run the same command many times.
5727 * Send break instead of ^C
5729 The standard remote protocol now includes an option to send a break
5730 rather than a ^C to the target in order to interrupt it. By default,
5731 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5733 * Remote protocol timeout
5735 The standard remote protocol includes a new variable `remotetimeout'
5736 that allows you to set the number of seconds before GDB gives up trying
5737 to read from the target. The default value is 2.
5739 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5741 By default GDB will automatically keep track of objects as they are
5742 loaded and unloaded by the dynamic linker. By using the command `set
5743 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5744 when shared library events occur, thus allowing you to set breakpoints
5745 in shared libraries which are explicitly loaded by the inferior.
5747 Note this feature does not work on hpux8. On hpux9 you must link
5748 /usr/lib/end.o into your program. This feature should work
5749 automatically on hpux10.
5751 * Irix 5.x hardware watchpoint support
5753 Irix 5 configurations now support the use of hardware watchpoints.
5755 * Mips protocol "SYN garbage limit"
5757 When debugging a Mips target using the `target mips' protocol, you
5758 may set the number of characters that GDB will ignore by setting
5759 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5760 every character. The default value is 1050.
5762 * Recording and replaying remote debug sessions
5764 If you set `remotelogfile' to the name of a file, gdb will write to it
5765 a recording of a remote debug session. This recording may then be
5766 replayed back to gdb using "gdbreplay". See gdbserver/README for
5767 details. This is useful when you have a problem with GDB while doing
5768 remote debugging; you can make a recording of the session and send it
5769 to someone else, who can then recreate the problem.
5771 * Speedups for remote debugging
5773 GDB includes speedups for downloading and stepping MIPS systems using
5774 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5775 and more efficient S-record downloading.
5777 * Memory use reductions and statistics collection
5779 GDB now uses less memory and reports statistics about memory usage.
5780 Try the `maint print statistics' command, for example.
5782 *** Changes in GDB-4.15:
5784 * Psymtabs for XCOFF
5786 The symbol reader for AIX GDB now uses partial symbol tables. This
5787 can greatly improve startup time, especially for large executables.
5789 * Remote targets use caching
5791 Remote targets now use a data cache to speed up communication with the
5792 remote side. The data cache could lead to incorrect results because
5793 it doesn't know about volatile variables, thus making it impossible to
5794 debug targets which use memory mapped I/O devices. `set remotecache
5795 off' turns the the data cache off.
5797 * Remote targets may have threads
5799 The standard remote protocol now includes support for multiple threads
5800 in the target system, using new protocol commands 'H' and 'T'. See
5801 gdb/remote.c for details.
5805 If GDB is configured with `--enable-netrom', then it will include
5806 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5807 acts as though it is a bank of ROM on the target board, but you can
5808 write into it over the network. GDB's support consists only of
5809 support for fast loading into the emulated ROM; to debug, you must use
5810 another protocol, such as standard remote protocol. The usual
5811 sequence is something like
5813 target nrom <netrom-hostname>
5815 target remote <netrom-hostname>:1235
5819 GDB now includes support for the Apple Macintosh, as a host only. It
5820 may be run as either an MPW tool or as a standalone application, and
5821 it can debug through the serial port. All the usual GDB commands are
5822 available, but to the target command, you must supply "serial" as the
5823 device type instead of "/dev/ttyXX". See mpw-README in the main
5824 directory for more information on how to build. The MPW configuration
5825 scripts */mpw-config.in support only a few targets, and only the
5826 mips-idt-ecoff target has been tested.
5830 GDB configuration now uses autoconf. This is not user-visible,
5831 but does simplify configuration and building.
5835 GDB now supports hpux10.
5837 *** Changes in GDB-4.14:
5839 * New native configurations
5841 x86 FreeBSD i[345]86-*-freebsd
5842 x86 NetBSD i[345]86-*-netbsd
5843 NS32k NetBSD ns32k-*-netbsd
5844 Sparc NetBSD sparc-*-netbsd
5848 A29K VxWorks a29k-*-vxworks
5849 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5850 CPU32 EST-300 emulator m68*-*-est*
5851 PowerPC ELF powerpc-*-elf
5854 * Alpha OSF/1 support for procfs
5856 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5857 possible to attach to running processes. As the mounting of the /proc
5858 filesystem is optional on the Alpha, GDB automatically determines
5859 the availability of /proc during startup. This can lead to problems
5860 if /proc is unmounted after GDB has been started.
5862 * Arguments to user-defined commands
5864 User commands may accept up to 10 arguments separated by whitespace.
5865 Arguments are accessed within the user command via $arg0..$arg9. A
5868 print $arg0 + $arg1 + $arg2
5870 To execute the command use:
5873 Defines the command "adder" which prints the sum of its three arguments.
5874 Note the arguments are text substitutions, so they may reference variables,
5875 use complex expressions, or even perform inferior function calls.
5877 * New `if' and `while' commands
5879 This makes it possible to write more sophisticated user-defined
5880 commands. Both commands take a single argument, which is the
5881 expression to evaluate, and must be followed by the commands to
5882 execute, one per line, if the expression is nonzero, the list being
5883 terminated by the word `end'. The `if' command list may include an
5884 `else' word, which causes the following commands to be executed only
5885 if the expression is zero.
5887 * Fortran source language mode
5889 GDB now includes partial support for Fortran 77. It will recognize
5890 Fortran programs and can evaluate a subset of Fortran expressions, but
5891 variables and functions may not be handled correctly. GDB will work
5892 with G77, but does not yet know much about symbols emitted by other
5895 * Better HPUX support
5897 Most debugging facilities now work on dynamic executables for HPPAs
5898 running hpux9 or later. You can attach to running dynamically linked
5899 processes, but by default the dynamic libraries will be read-only, so
5900 for instance you won't be able to put breakpoints in them. To change
5901 that behavior do the following before running the program:
5907 This will cause the libraries to be mapped private and read-write.
5908 To revert to the normal behavior, do this:
5914 You cannot set breakpoints or examine data in the library until after
5915 the library is loaded if the function/data symbols do not have
5918 GDB can now also read debug symbols produced by the HP C compiler on
5919 HPPAs (sorry, no C++, Fortran or 68k support).
5921 * Target byte order now dynamically selectable
5923 You can choose which byte order to use with a target system, via the
5924 commands "set endian big" and "set endian little", and you can see the
5925 current setting by using "show endian". You can also give the command
5926 "set endian auto", in which case GDB will use the byte order
5927 associated with the executable. Currently, only embedded MIPS
5928 configurations support dynamic selection of target byte order.
5930 * New DOS host serial code
5932 This version uses DPMI interrupts to handle buffered I/O, so you
5933 no longer need to run asynctsr when debugging boards connected to
5936 *** Changes in GDB-4.13:
5938 * New "complete" command
5940 This lists all the possible completions for the rest of the line, if it
5941 were to be given as a command itself. This is intended for use by emacs.
5943 * Trailing space optional in prompt
5945 "set prompt" no longer adds a space for you after the prompt you set. This
5946 allows you to set a prompt which ends in a space or one that does not.
5948 * Breakpoint hit counts
5950 "info break" now displays a count of the number of times the breakpoint
5951 has been hit. This is especially useful in conjunction with "ignore"; you
5952 can ignore a large number of breakpoint hits, look at the breakpoint info
5953 to see how many times the breakpoint was hit, then run again, ignoring one
5954 less than that number, and this will get you quickly to the last hit of
5957 * Ability to stop printing at NULL character
5959 "set print null-stop" will cause GDB to stop printing the characters of
5960 an array when the first NULL is encountered. This is useful when large
5961 arrays actually contain only short strings.
5963 * Shared library breakpoints
5965 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5966 breakpoints in shared libraries before the executable is run.
5968 * Hardware watchpoints
5970 There is a new hardware breakpoint for the watch command for sparclite
5971 targets. See gdb/sparclite/hw_breakpoint.note.
5973 Hardware watchpoints are also now supported under GNU/Linux.
5977 Annotations have been added. These are for use with graphical interfaces,
5978 and are still experimental. Currently only gdba.el uses these.
5980 * Improved Irix 5 support
5982 GDB now works properly with Irix 5.2.
5984 * Improved HPPA support
5986 GDB now works properly with the latest GCC and GAS.
5988 * New native configurations
5990 Sequent PTX4 i[34]86-sequent-ptx4
5991 HPPA running OSF/1 hppa*-*-osf*
5992 Atari TT running SVR4 m68*-*-sysv4*
5993 RS/6000 LynxOS rs6000-*-lynxos*
5997 OS/9000 i[34]86-*-os9k
5998 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6001 * Hitachi SH7000 and E7000-PC ICE support
6003 There is now support for communicating with the Hitachi E7000-PC ICE.
6004 This is available automatically when GDB is configured for the SH.
6008 As usual, a variety of small fixes and improvements, both generic
6009 and configuration-specific. See the ChangeLog for more detail.
6011 *** Changes in GDB-4.12:
6013 * Irix 5 is now supported
6017 GDB-4.12 on the HPPA has a number of changes which make it unable
6018 to debug the output from the currently released versions of GCC and
6019 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6020 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6021 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6024 *** Changes in GDB-4.11:
6026 * User visible changes:
6030 The "set remotedebug" option is now consistent between the mips remote
6031 target, remote targets using the gdb-specific protocol, UDI (AMD's
6032 debug protocol for the 29k) and the 88k bug monitor. It is now an
6033 integer specifying a debug level (normally 0 or 1, but 2 means more
6034 debugging info for the mips target).
6036 * DEC Alpha native support
6038 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6039 debug info, but GDB works fairly well with the DEC compiler and should
6040 work with a future GCC release. See the README file for a few
6041 Alpha-specific notes.
6043 * Preliminary thread implementation
6045 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6047 * LynxOS native and target support for 386
6049 This release has been hosted on LynxOS 2.2, and also can be configured
6050 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6053 * Improvements in C++ mangling/demangling.
6055 This release has much better g++ debugging, specifically in name
6056 mangling/demangling, virtual function calls, print virtual table,
6057 call methods, ...etc.
6059 *** Changes in GDB-4.10:
6061 * User visible changes:
6063 Remote debugging using the GDB-specific (`target remote') protocol now
6064 supports the `load' command. This is only useful if you have some
6065 other way of getting the stub to the target system, and you can put it
6066 somewhere in memory where it won't get clobbered by the download.
6068 Filename completion now works.
6070 When run under emacs mode, the "info line" command now causes the
6071 arrow to point to the line specified. Also, "info line" prints
6072 addresses in symbolic form (as well as hex).
6074 All vxworks based targets now support a user settable option, called
6075 vxworks-timeout. This option represents the number of seconds gdb
6076 should wait for responses to rpc's. You might want to use this if
6077 your vxworks target is, perhaps, a slow software simulator or happens
6078 to be on the far side of a thin network line.
6082 This release contains support for using a DEC alpha as a GDB host for
6083 cross debugging. Native alpha debugging is not supported yet.
6086 *** Changes in GDB-4.9:
6090 This is the first GDB release which is accompanied by a matching testsuite.
6091 The testsuite requires installation of dejagnu, which should be available
6092 via ftp from most sites that carry GNU software.
6096 'Cfront' style demangling has had its name changed to 'ARM' style, to
6097 emphasize that it was written from the specifications in the C++ Annotated
6098 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6099 disclaimers, it still generated too much confusion with users attempting to
6100 use gdb with AT&T cfront.
6104 GDB now uses a standard remote interface to a simulator library.
6105 So far, the library contains simulators for the Zilog Z8001/2, the
6106 Hitachi H8/300, H8/500 and Super-H.
6108 * New targets supported
6110 H8/300 simulator h8300-hitachi-hms or h8300hms
6111 H8/500 simulator h8500-hitachi-hms or h8500hms
6112 SH simulator sh-hitachi-hms or sh
6113 Z8000 simulator z8k-zilog-none or z8ksim
6114 IDT MIPS board over serial line mips-idt-ecoff
6116 Cross-debugging to GO32 targets is supported. It requires a custom
6117 version of the i386-stub.c module which is integrated with the
6118 GO32 memory extender.
6120 * New remote protocols
6122 MIPS remote debugging protocol.
6124 * New source languages supported
6126 This version includes preliminary support for Chill, a Pascal like language
6127 used by telecommunications companies. Chill support is also being integrated
6128 into the GNU compiler, but we don't know when it will be publically available.
6131 *** Changes in GDB-4.8:
6133 * HP Precision Architecture supported
6135 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6136 version of this support was available as a set of patches from the
6137 University of Utah. GDB does not support debugging of programs
6138 compiled with the HP compiler, because HP will not document their file
6139 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6140 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6142 Many problems in the preliminary version have been fixed.
6144 * Faster and better demangling
6146 We have improved template demangling and fixed numerous bugs in the GNU style
6147 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6148 character types (wchar_t) are now supported. Demangling of each symbol is now
6149 only done once, and is cached when the symbol table for a file is read in.
6150 This results in a small increase in memory usage for C programs, a moderate
6151 increase in memory usage for C++ programs, and a fantastic speedup in
6154 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6155 from the specifications in the Annotated Reference Manual, which AT&T's
6156 compiler does not actually implement.
6158 * G++ multiple inheritance compiler problem
6160 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6161 inheritance lattices was reworked to properly discover ambiguities. We
6162 recently found an example which causes this new algorithm to fail in a
6163 very subtle way, producing bad debug information for those classes.
6164 The file 'gcc.patch' (in this directory) can be applied to gcc to
6165 circumvent the problem. A future GCC release will contain a complete
6168 The previous G++ debug info problem (mentioned below for the gdb-4.7
6169 release) is fixed in gcc version 2.3.2.
6171 * Improved configure script
6173 The `configure' script will now attempt to guess your system type if
6174 you don't supply a host system type. The old scheme of supplying a
6175 host system triplet is preferable over using this. All the magic is
6176 done in the new `config.guess' script. Examine it for details.
6178 We have also brought our configure script much more in line with the FSF's
6179 version. It now supports the --with-xxx options. In particular,
6180 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6181 The resulting GDB will not be able to read arbitrary object file formats --
6182 only the format ``expected'' to be used on the configured target system.
6183 We hope to make this the default in a future release.
6185 * Documentation improvements
6187 There's new internal documentation on how to modify GDB, and how to
6188 produce clean changes to the code. We implore people to read it
6189 before submitting changes.
6191 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6192 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6193 `info' files are also provided. To build `info' files from scratch,
6194 you will need the latest `makeinfo' release, which will be available in
6195 a future texinfo-X.Y release.
6197 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6198 We're not sure exactly which versions have this problem, but it has
6199 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6200 or better. If that isn't possible, there is a patch in
6201 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6202 around this problem.
6206 GDB now supports array constants that can be used in expressions typed in by
6207 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6208 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6211 The new directory `gdb/sparclite' contains a program that demonstrates
6212 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6214 * New native hosts supported
6216 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6217 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6219 * New targets supported
6221 AMD 29k family via UDI a29k-amd-udi or udi29k
6223 * New file formats supported
6225 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6226 HPUX core files, and SCO 3.2v2 core files.
6230 Attaching to processes now works again; thanks for the many bug reports.
6232 We have also stomped on a bunch of core dumps caused by
6233 printf_filtered("%s") problems.
6235 We eliminated a copyright problem on the rpc and ptrace header files
6236 for VxWorks, which was discovered at the last minute during the 4.7
6237 release. You should now be able to build a VxWorks GDB.
6239 You can now interrupt gdb while an attached process is running. This
6240 will cause the attached process to stop, and give control back to GDB.
6242 We fixed problems caused by using too many file descriptors
6243 for reading symbols from object files and libraries. This was
6244 especially a problem for programs that used many (~100) shared
6247 The `step' command now only enters a subroutine if there is line number
6248 information for the subroutine. Otherwise it acts like the `next'
6249 command. Previously, `step' would enter subroutines if there was
6250 any debugging information about the routine. This avoids problems
6251 when using `cc -g1' on MIPS machines.
6253 * Internal improvements
6255 GDB's internal interfaces have been improved to make it easier to support
6256 debugging of multiple languages in the future.
6258 GDB now uses a common structure for symbol information internally.
6259 Minimal symbols (derived from linkage symbols in object files), partial
6260 symbols (from a quick scan of debug information), and full symbols
6261 contain a common subset of information, making it easier to write
6262 shared code that handles any of them.
6264 * New command line options
6266 We now accept --silent as an alias for --quiet.
6270 The memory-mapped-malloc library is now licensed under the GNU Library
6271 General Public License.
6273 *** Changes in GDB-4.7:
6275 * Host/native/target split
6277 GDB has had some major internal surgery to untangle the support for
6278 hosts and remote targets. Now, when you configure GDB for a remote
6279 target, it will no longer load in all of the support for debugging
6280 local programs on the host. When fully completed and tested, this will
6281 ensure that arbitrary host/target combinations are possible.
6283 The primary conceptual shift is to separate the non-portable code in
6284 GDB into three categories. Host specific code is required any time GDB
6285 is compiled on that host, regardless of the target. Target specific
6286 code relates to the peculiarities of the target, but can be compiled on
6287 any host. Native specific code is everything else: it can only be
6288 built when the host and target are the same system. Child process
6289 handling and core file support are two common `native' examples.
6291 GDB's use of /proc for controlling Unix child processes is now cleaner.
6292 It has been split out into a single module under the `target_ops' vector,
6293 plus two native-dependent functions for each system that uses /proc.
6295 * New hosts supported
6297 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6298 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6299 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6301 * New targets supported
6303 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6304 68030 and CPU32 m68030-*-*, m68332-*-*
6306 * New native hosts supported
6308 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6309 (386bsd is not well tested yet)
6310 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6312 * New file formats supported
6314 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6315 supports reading of `a.out.adobe' object files, which are an a.out
6316 format extended with minimal information about multiple sections.
6320 `show copying' is the same as the old `info copying'.
6321 `show warranty' is the same as `info warrantee'.
6322 These were renamed for consistency. The old commands continue to work.
6324 `info handle' is a new alias for `info signals'.
6326 You can now define pre-command hooks, which attach arbitrary command
6327 scripts to any command. The commands in the hook will be executed
6328 prior to the user's command. You can also create a hook which will be
6329 executed whenever the program stops. See gdb.texinfo.
6333 We now deal with Cfront style name mangling, and can even extract type
6334 info from mangled symbols. GDB can automatically figure out which
6335 symbol mangling style your C++ compiler uses.
6337 Calling of methods and virtual functions has been improved as well.
6341 The crash that occured when debugging Sun Ansi-C compiled binaries is
6342 fixed. This was due to mishandling of the extra N_SO stabs output
6345 We also finally got Ultrix 4.2 running in house, and fixed core file
6346 support, with help from a dozen people on the net.
6348 John M. Farrell discovered that the reason that single-stepping was so
6349 slow on all of the Mips based platforms (primarily SGI and DEC) was
6350 that we were trying to demangle and lookup a symbol used for internal
6351 purposes on every instruction that was being stepped through. Changing
6352 the name of that symbol so that it couldn't be mistaken for a C++
6353 mangled symbol sped things up a great deal.
6355 Rich Pixley sped up symbol lookups in general by getting much smarter
6356 about when C++ symbol mangling is necessary. This should make symbol
6357 completion (TAB on the command line) much faster. It's not as fast as
6358 we'd like, but it's significantly faster than gdb-4.6.
6362 A new user controllable variable 'call_scratch_address' can
6363 specify the location of a scratch area to be used when GDB
6364 calls a function in the target. This is necessary because the
6365 usual method of putting the scratch area on the stack does not work
6366 in systems that have separate instruction and data spaces.
6368 We integrated changes to support the 29k UDI (Universal Debugger
6369 Interface), but discovered at the last minute that we didn't have all
6370 of the appropriate copyright paperwork. We are working with AMD to
6371 resolve this, and hope to have it available soon.
6375 We have sped up the remote serial line protocol, especially for targets
6376 with lots of registers. It now supports a new `expedited status' ('T')
6377 message which can be used in place of the existing 'S' status message.
6378 This allows the remote stub to send only the registers that GDB
6379 needs to make a quick decision about single-stepping or conditional
6380 breakpoints, eliminating the need to fetch the entire register set for
6381 each instruction being stepped through.
6383 The GDB remote serial protocol now implements a write-through cache for
6384 registers, only re-reading the registers if the target has run.
6386 There is also a new remote serial stub for SPARC processors. You can
6387 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6388 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6389 processor with a serial port.
6393 Configure.in files have become much easier to read and modify. A new
6394 `table driven' format makes it more obvious what configurations are
6395 supported, and what files each one uses.
6399 There is a new opcodes library which will eventually contain all of the
6400 disassembly routines and opcode tables. At present, it only contains
6401 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6402 disassembler (binutils/objdump) to share these routines.
6404 The libiberty library is now copylefted under the GNU Library General
6405 Public License. This allows more liberal use, and was done so libg++
6406 can use it. This makes no difference to GDB, since the Library License
6407 grants all the rights from the General Public License.
6411 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6412 reference to the stabs symbol info used by the debugger. It is (as far
6413 as we know) the only published document on this fascinating topic. We
6414 encourage you to read it, compare it to the stabs information on your
6415 system, and send improvements on the document in general (to
6416 bug-gdb@prep.ai.mit.edu).
6418 And, of course, many bugs have been fixed.
6421 *** Changes in GDB-4.6:
6423 * Better support for C++ function names
6425 GDB now accepts as input the "demangled form" of C++ overloaded function
6426 names and member function names, and can do command completion on such names
6427 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6428 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6429 Make use of command completion, it is your friend.
6431 GDB also now accepts a variety of C++ mangled symbol formats. They are
6432 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6433 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6434 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6435 for the list of formats.
6437 * G++ symbol mangling problem
6439 Recent versions of gcc have a bug in how they emit debugging information for
6440 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6441 directory) can be applied to gcc to fix the problem. Alternatively, if you
6442 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6443 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6444 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6447 * New 'maintenance' command
6449 All of the commands related to hacking GDB internals have been moved out of
6450 the main command set, and now live behind the 'maintenance' command. This
6451 can also be abbreviated as 'mt'. The following changes were made:
6453 dump-me -> maintenance dump-me
6454 info all-breakpoints -> maintenance info breakpoints
6455 printmsyms -> maintenance print msyms
6456 printobjfiles -> maintenance print objfiles
6457 printpsyms -> maintenance print psymbols
6458 printsyms -> maintenance print symbols
6460 The following commands are new:
6462 maintenance demangle Call internal GDB demangler routine to
6463 demangle a C++ link name and prints the result.
6464 maintenance print type Print a type chain for a given symbol
6466 * Change to .gdbinit file processing
6468 We now read the $HOME/.gdbinit file before processing the argv arguments
6469 (e.g. reading symbol files or core files). This allows global parameters to
6470 be set, which will apply during the symbol reading. The ./.gdbinit is still
6471 read after argv processing.
6473 * New hosts supported
6475 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6477 GNU/Linux support i386-unknown-linux or linux
6479 We are also including code to support the HP/PA running BSD and HPUX. This
6480 is almost guaranteed not to work, as we didn't have time to test or build it
6481 for this release. We are including it so that the more adventurous (or
6482 masochistic) of you can play with it. We also had major problems with the
6483 fact that the compiler that we got from HP doesn't support the -g option.
6486 * New targets supported
6488 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6490 * More smarts about finding #include files
6492 GDB now remembers the compilation directory for all include files, and for
6493 all files from which C is generated (like yacc and lex sources). This
6494 greatly improves GDB's ability to find yacc/lex sources, and include files,
6495 especially if you are debugging your program from a directory different from
6496 the one that contains your sources.
6498 We also fixed a bug which caused difficulty with listing and setting
6499 breakpoints in include files which contain C code. (In the past, you had to
6500 try twice in order to list an include file that you hadn't looked at before.)
6502 * Interesting infernals change
6504 GDB now deals with arbitrary numbers of sections, where the symbols for each
6505 section must be relocated relative to that section's landing place in the
6506 target's address space. This work was needed to support ELF with embedded
6507 stabs used by Solaris-2.0.
6509 * Bug fixes (of course!)
6511 There have been loads of fixes for the following things:
6512 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6513 i960, stabs, DOS(GO32), procfs, etc...
6515 See the ChangeLog for details.
6517 *** Changes in GDB-4.5:
6519 * New machines supported (host and target)
6521 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6523 SGI Irix-4.x mips-sgi-irix4 or iris4
6525 * New malloc package
6527 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6528 Mmalloc is capable of handling mutiple heaps of memory. It is also
6529 capable of saving a heap to a file, and then mapping it back in later.
6530 This can be used to greatly speedup the startup of GDB by using a
6531 pre-parsed symbol table which lives in a mmalloc managed heap. For
6532 more details, please read mmalloc/mmalloc.texi.
6536 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6537 'help info proc' for details.
6539 * MIPS ecoff symbol table format
6541 The code that reads MIPS symbol table format is now supported on all hosts.
6542 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6545 * File name changes for MS-DOS
6547 Many files in the config directories have been renamed to make it easier to
6548 support GDB on MS-DOSe systems (which have very restrictive file name
6549 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6550 environment) is close to working but has some remaining problems. Note
6551 that debugging of DOS programs is not supported, due to limitations
6552 in the ``operating system'', but it can be used to host cross-debugging.
6554 * Cross byte order fixes
6556 Many fixes have been made to support cross debugging of Sparc and MIPS
6557 targets from hosts whose byte order differs.
6559 * New -mapped and -readnow options
6561 If memory-mapped files are available on your system through the 'mmap'
6562 system call, you can use the -mapped option on the `file' or
6563 `symbol-file' commands to cause GDB to write the symbols from your
6564 program into a reusable file. If the program you are debugging is
6565 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6566 Future GDB debugging sessions will notice the presence of this file,
6567 and will quickly map in symbol information from it, rather than reading
6568 the symbol table from the executable program. Using the '-mapped'
6569 option in a GDB `file' or `symbol-file' command has the same effect as
6570 starting GDB with the '-mapped' command-line option.
6572 You can cause GDB to read the entire symbol table immediately by using
6573 the '-readnow' option with any of the commands that load symbol table
6574 information (or on the GDB command line). This makes the command
6575 slower, but makes future operations faster.
6577 The -mapped and -readnow options are typically combined in order to
6578 build a `fred.syms' file that contains complete symbol information.
6579 A simple GDB invocation to do nothing but build a `.syms' file for future
6582 gdb -batch -nx -mapped -readnow programname
6584 The `.syms' file is specific to the host machine on which GDB is run.
6585 It holds an exact image of GDB's internal symbol table. It cannot be
6586 shared across multiple host platforms.
6588 * longjmp() handling
6590 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6591 siglongjmp() without losing control. This feature has not yet been ported to
6592 all systems. It currently works on many 386 platforms, all MIPS-based
6593 platforms (SGI, DECstation, etc), and Sun3/4.
6597 Preliminary work has been put in to support the new Solaris OS from Sun. At
6598 this time, it can control and debug processes, but it is not capable of
6603 As always, many many bug fixes. The major areas were with g++, and mipsread.
6604 People using the MIPS-based platforms should experience fewer mysterious
6605 crashes and trashed symbol tables.
6607 *** Changes in GDB-4.4:
6609 * New machines supported (host and target)
6611 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6613 BSD Reno on Vax vax-dec-bsd
6614 Ultrix on Vax vax-dec-ultrix
6616 * New machines supported (target)
6618 AMD 29000 embedded, using EBMON a29k-none-none
6622 GDB continues to improve its handling of C++. `References' work better.
6623 The demangler has also been improved, and now deals with symbols mangled as
6624 per the Annotated C++ Reference Guide.
6626 GDB also now handles `stabs' symbol information embedded in MIPS
6627 `ecoff' symbol tables. Since the ecoff format was not easily
6628 extensible to handle new languages such as C++, this appeared to be a
6629 good way to put C++ debugging info into MIPS binaries. This option
6630 will be supported in the GNU C compiler, version 2, when it is
6633 * New features for SVR4
6635 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6636 shared libraries. Debugging dynamically linked programs should present
6637 only minor differences from debugging statically linked programs.
6639 The `info proc' command will print out information about any process
6640 on an SVR4 system (including the one you are debugging). At the moment,
6641 it prints the address mappings of the process.
6643 If you bring up GDB on another SVR4 system, please send mail to
6644 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6646 * Better dynamic linking support in SunOS
6648 Reading symbols from shared libraries which contain debugging symbols
6649 now works properly. However, there remain issues such as automatic
6650 skipping of `transfer vector' code during function calls, which
6651 make it harder to debug code in a shared library, than to debug the
6652 same code linked statically.
6656 GDB is now using the latest `getopt' routines from the FSF. This
6657 version accepts the -- prefix for options with long names. GDB will
6658 continue to accept the old forms (-option and +option) as well.
6659 Various single letter abbreviations for options have been explicity
6660 added to the option table so that they won't get overshadowed in the
6661 future by other options that begin with the same letter.
6665 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6666 Many assorted bugs have been handled. Many more remain to be handled.
6667 See the various ChangeLog files (primarily in gdb and bfd) for details.
6670 *** Changes in GDB-4.3:
6672 * New machines supported (host and target)
6674 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6675 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6676 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6678 * Almost SCO Unix support
6680 We had hoped to support:
6681 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6682 (except for core file support), but we discovered very late in the release
6683 that it has problems with process groups that render gdb unusable. Sorry
6684 about that. I encourage people to fix it and post the fixes.
6686 * Preliminary ELF and DWARF support
6688 GDB can read ELF object files on System V Release 4, and can handle
6689 debugging records for C, in DWARF format, in ELF files. This support
6690 is preliminary. If you bring up GDB on another SVR4 system, please
6691 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6696 GDB now uses the latest `readline' library. One user-visible change
6697 is that two tabs will list possible command completions, which previously
6698 required typing M-? (meta-question mark, or ESC ?).
6702 The `stepi' bug that many of you noticed has been squashed.
6703 Many bugs in C++ have been handled. Many more remain to be handled.
6704 See the various ChangeLog files (primarily in gdb and bfd) for details.
6706 * State of the MIPS world (in case you wondered):
6708 GDB can understand the symbol tables emitted by the compilers
6709 supplied by most vendors of MIPS-based machines, including DEC. These
6710 symbol tables are in a format that essentially nobody else uses.
6712 Some versions of gcc come with an assembler post-processor called
6713 mips-tfile. This program is required if you want to do source-level
6714 debugging of gcc-compiled programs. I believe FSF does not ship
6715 mips-tfile with gcc version 1, but it will eventually come with gcc
6718 Debugging of g++ output remains a problem. g++ version 1.xx does not
6719 really support it at all. (If you're lucky, you should be able to get
6720 line numbers and stack traces to work, but no parameters or local
6721 variables.) With some work it should be possible to improve the
6724 When gcc version 2 is released, you will have somewhat better luck.
6725 However, even then you will get confusing results for inheritance and
6728 We will eventually provide full debugging of g++ output on
6729 DECstations. This will probably involve some kind of stabs-in-ecoff
6730 encapulation, but the details have not been worked out yet.
6733 *** Changes in GDB-4.2:
6735 * Improved configuration
6737 Only one copy of `configure' exists now, and it is not self-modifying.
6738 Porting BFD is simpler.
6742 The `step' and `next' commands now only stop at the first instruction
6743 of a source line. This prevents the multiple stops that used to occur
6744 in switch statements, for-loops, etc. `Step' continues to stop if a
6745 function that has debugging information is called within the line.
6749 Lots of small bugs fixed. More remain.
6751 * New host supported (not target)
6753 Intel 386 PC clone running Mach i386-none-mach
6756 *** Changes in GDB-4.1:
6758 * Multiple source language support
6760 GDB now has internal scaffolding to handle several source languages.
6761 It determines the type of each source file from its filename extension,
6762 and will switch expression parsing and number formatting to match the
6763 language of the function in the currently selected stack frame.
6764 You can also specifically set the language to be used, with
6765 `set language c' or `set language modula-2'.
6769 GDB now has preliminary support for the GNU Modula-2 compiler,
6770 currently under development at the State University of New York at
6771 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6772 continue through the fall of 1991 and into 1992.
6774 Other Modula-2 compilers are currently not supported, and attempting to
6775 debug programs compiled with them will likely result in an error as the
6776 symbol table is read. Feel free to work on it, though!
6778 There are hooks in GDB for strict type checking and range checking,
6779 in the `Modula-2 philosophy', but they do not currently work.
6783 GDB can now write to executable and core files (e.g. patch
6784 a variable's value). You must turn this switch on, specify
6785 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6786 by assigning a new value to a variable. Modifications take
6789 * Automatic SunOS shared library reading
6791 When you run your program, GDB automatically determines where its
6792 shared libraries (if any) have been loaded, and reads their symbols.
6793 The `share' command is no longer needed. This also works when
6794 examining core files.
6798 You can specify the number of lines that the `list' command shows.
6801 * New machines supported (host and target)
6803 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6804 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6805 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6807 * New hosts supported (not targets)
6809 IBM RT/PC: romp-ibm-aix or rtpc
6811 * New targets supported (not hosts)
6813 AMD 29000 embedded with COFF a29k-none-coff
6814 AMD 29000 embedded with a.out a29k-none-aout
6815 Ultracomputer remote kernel debug a29k-nyu-kern
6817 * New remote interfaces
6823 *** Changes in GDB-4.0:
6827 Wide output is wrapped at good places to make the output more readable.
6829 Gdb now supports cross-debugging from a host machine of one type to a
6830 target machine of another type. Communication with the target system
6831 is over serial lines. The ``target'' command handles connecting to the
6832 remote system; the ``load'' command will download a program into the
6833 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6834 also supports debugging of realtime processes running under VxWorks,
6835 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6836 stub on the target system.
6838 New CPUs supported include the AMD 29000 and Intel 960.
6840 GDB now reads object files and symbol tables via a ``binary file''
6841 library, which allows a single copy of GDB to debug programs of multiple
6842 object file types such as a.out and coff.
6844 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6845 refcard.dvi and refcard.ps are available to format it).
6848 * Control-Variable user interface simplified
6850 All variables that control the operation of the debugger can be set
6851 by the ``set'' command, and displayed by the ``show'' command.
6853 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6854 ``Show prompt'' produces the response:
6855 Gdb's prompt is new-gdb=>.
6857 What follows are the NEW set commands. The command ``help set'' will
6858 print a complete list of old and new set commands. ``help set FOO''
6859 will give a longer description of the variable FOO. ``show'' will show
6860 all of the variable descriptions and their current settings.
6862 confirm on/off: Enables warning questions for operations that are
6863 hard to recover from, e.g. rerunning the program while
6864 it is already running. Default is ON.
6866 editing on/off: Enables EMACS style command line editing
6867 of input. Previous lines can be recalled with
6868 control-P, the current line can be edited with control-B,
6869 you can search for commands with control-R, etc.
6872 history filename NAME: NAME is where the gdb command history
6873 will be stored. The default is .gdb_history,
6874 or the value of the environment variable
6877 history size N: The size, in commands, of the command history. The
6878 default is 256, or the value of the environment variable
6881 history save on/off: If this value is set to ON, the history file will
6882 be saved after exiting gdb. If set to OFF, the
6883 file will not be saved. The default is OFF.
6885 history expansion on/off: If this value is set to ON, then csh-like
6886 history expansion will be performed on
6887 command line input. The default is OFF.
6889 radix N: Sets the default radix for input and output. It can be set
6890 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6891 in the current radix, so "set radix 10" is always a no-op.
6893 height N: This integer value is the number of lines on a page. Default
6894 is 24, the current `stty rows'' setting, or the ``li#''
6895 setting from the termcap entry matching the environment
6898 width N: This integer value is the number of characters on a line.
6899 Default is 80, the current `stty cols'' setting, or the ``co#''
6900 setting from the termcap entry matching the environment
6903 Note: ``set screensize'' is obsolete. Use ``set height'' and
6904 ``set width'' instead.
6906 print address on/off: Print memory addresses in various command displays,
6907 such as stack traces and structure values. Gdb looks
6908 more ``symbolic'' if you turn this off; it looks more
6909 ``machine level'' with it on. Default is ON.
6911 print array on/off: Prettyprint arrays. New convenient format! Default
6914 print demangle on/off: Print C++ symbols in "source" form if on,
6917 print asm-demangle on/off: Same, for assembler level printouts
6920 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6923 * Support for Epoch Environment.
6925 The epoch environment is a version of Emacs v18 with windowing. One
6926 new command, ``inspect'', is identical to ``print'', except that if you
6927 are running in the epoch environment, the value is printed in its own
6931 * Support for Shared Libraries
6933 GDB can now debug programs and core files that use SunOS shared libraries.
6934 Symbols from a shared library cannot be referenced
6935 before the shared library has been linked with the program (this
6936 happens after you type ``run'' and before the function main() is entered).
6937 At any time after this linking (including when examining core files
6938 from dynamically linked programs), gdb reads the symbols from each
6939 shared library when you type the ``sharedlibrary'' command.
6940 It can be abbreviated ``share''.
6942 sharedlibrary REGEXP: Load shared object library symbols for files
6943 matching a unix regular expression. No argument
6944 indicates to load symbols for all shared libraries.
6946 info sharedlibrary: Status of loaded shared libraries.
6951 A watchpoint stops execution of a program whenever the value of an
6952 expression changes. Checking for this slows down execution
6953 tremendously whenever you are in the scope of the expression, but is
6954 quite useful for catching tough ``bit-spreader'' or pointer misuse
6955 problems. Some machines such as the 386 have hardware for doing this
6956 more quickly, and future versions of gdb will use this hardware.
6958 watch EXP: Set a watchpoint (breakpoint) for an expression.
6960 info watchpoints: Information about your watchpoints.
6962 delete N: Deletes watchpoint number N (same as breakpoints).
6963 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6964 enable N: Re-enables watchpoint number N (same as breakpoints).
6967 * C++ multiple inheritance
6969 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6972 * C++ exception handling
6974 Gdb now supports limited C++ exception handling. Besides the existing
6975 ability to breakpoint on an exception handler, gdb can breakpoint on
6976 the raising of an exception (before the stack is peeled back to the
6979 catch FOO: If there is a FOO exception handler in the dynamic scope,
6980 set a breakpoint to catch exceptions which may be raised there.
6981 Multiple exceptions (``catch foo bar baz'') may be caught.
6983 info catch: Lists all exceptions which may be caught in the
6984 current stack frame.
6987 * Minor command changes
6989 The command ``call func (arg, arg, ...)'' now acts like the print
6990 command, except it does not print or save a value if the function's result
6991 is void. This is similar to dbx usage.
6993 The ``up'' and ``down'' commands now always print the frame they end up
6994 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6995 frames without printing.
6997 * New directory command
6999 'dir' now adds directories to the FRONT of the source search path.
7000 The path starts off empty. Source files that contain debug information
7001 about the directory in which they were compiled can be found even
7002 with an empty path; Sun CC and GCC include this information. If GDB can't
7003 find your source file in the current directory, type "dir .".
7005 * Configuring GDB for compilation
7007 For normal use, type ``./configure host''. See README or gdb.texinfo
7010 GDB now handles cross debugging. If you are remotely debugging between
7011 two different machines, type ``./configure host -target=targ''.
7012 Host is the machine where GDB will run; targ is the machine
7013 where the program that you are debugging will run.