1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.1
6 * The endianness used with the 'set endian auto' mode in the absence of
7 an executable selected for debugging is now the last endianness chosen
8 either by one of the 'set endian big' and 'set endian little' commands
9 or by inferring from the last executable used, rather than the startup
12 * The commands 'info variables/functions/types' now show the source line
13 numbers of symbol definitions when available.
15 * 'info proc' now works on running processes on FreeBSD systems and core
16 files created on FreeBSD systems.
18 * C expressions can now use _Alignof, and C++ expressions can now use
25 Control display of debugging info regarding the FreeBSD native target.
27 set|show varsize-limit
28 This new setting allows the user to control the maximum size of Ada
29 objects being printed when those objects have a variable type,
30 instead of that maximum size being hardcoded to 65536 bytes.
32 set|show record btrace cpu
33 Controls the processor to be used for enabling errata workarounds for
38 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
40 ** The commands attached to a breakpoint can be set by assigning to
41 the breakpoint's "commands" field.
43 ** gdb.execute can now execute multi-line gdb commands.
47 RiscV ELF riscv*-*-elf
49 * Removed targets and native configurations
51 m88k running OpenBSD m88*-*-openbsd*
52 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
53 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
54 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
56 * Aarch64/Linux hardware watchpoints improvements
58 Hardware watchpoints on unaligned addresses are now properly
59 supported when running Linux kernel 4.10 or higher: read and access
60 watchpoints are no longer spuriously missed, and all watchpoints
61 lengths between 1 and 8 bytes are supported. On older kernels,
62 watchpoints set on unaligned addresses are no longer missed, with
63 the tradeoff that there is a possibility of false hits being
66 *** Changes in GDB 8.1
68 * GDB now supports dynamically creating arbitrary register groups specified
69 in XML target descriptions. This allows for finer grain grouping of
70 registers on systems with a large amount of registers.
72 * The 'ptype' command now accepts a '/o' flag, which prints the
73 offsets and sizes of fields in a struct, like the pahole(1) tool.
75 * New "--readnever" command line option instructs GDB to not read each
76 symbol file's symbolic debug information. This makes startup faster
77 but at the expense of not being able to perform symbolic debugging.
78 This option is intended for use cases where symbolic debugging will
79 not be used, e.g., when you only need to dump the debuggee's core.
81 * GDB now uses the GNU MPFR library, if available, to emulate target
82 floating-point arithmetic during expression evaluation when the target
83 uses different floating-point formats than the host. At least version
84 3.1 of GNU MPFR is required.
86 * GDB now supports access to the guarded-storage-control registers and the
87 software-based guarded-storage broadcast control registers on IBM z14.
89 * On Unix systems, GDB now supports transmitting environment variables
90 that are to be set or unset to GDBserver. These variables will
91 affect the environment to be passed to the remote inferior.
93 To inform GDB of environment variables that are to be transmitted to
94 GDBserver, use the "set environment" command. Only user set
95 environment variables are sent to GDBserver.
97 To inform GDB of environment variables that are to be unset before
98 the remote inferior is started by the GDBserver, use the "unset
101 * Completion improvements
103 ** GDB can now complete function parameters in linespecs and
104 explicit locations without quoting. When setting breakpoints,
105 quoting around functions names to help with TAB-completion is
106 generally no longer necessary. For example, this now completes
109 (gdb) b function(in[TAB]
110 (gdb) b function(int)
112 Related, GDB is no longer confused with completing functions in
113 C++ anonymous namespaces:
116 (gdb) b (anonymous namespace)::[TAB][TAB]
117 (anonymous namespace)::a_function()
118 (anonymous namespace)::b_function()
120 ** GDB now has much improved linespec and explicit locations TAB
121 completion support, that better understands what you're
122 completing and offers better suggestions. For example, GDB no
123 longer offers data symbols as possible completions when you're
124 setting a breakpoint.
126 ** GDB now TAB-completes label symbol names.
128 ** The "complete" command now mimics TAB completion accurately.
130 * New command line options (gcore)
133 Dump all memory mappings.
135 * Breakpoints on C++ functions are now set on all scopes by default
137 By default, breakpoints on functions/methods are now interpreted as
138 specifying all functions with the given name ignoring missing
139 leading scopes (namespaces and classes).
141 For example, assuming a C++ program with symbols named:
146 both commands "break func()" and "break B::func()" set a breakpoint
149 You can use the new flag "-qualified" to override this. This makes
150 GDB interpret the specified function name as a complete
151 fully-qualified name instead. For example, using the same C++
152 program, the "break -q B::func" command sets a breakpoint on
153 "B::func", only. A parameter has been added to the Python
154 gdb.Breakpoint constructor to achieve the same result when creating
155 a breakpoint from Python.
157 * Breakpoints on functions marked with C++ ABI tags
159 GDB can now set breakpoints on functions marked with C++ ABI tags
160 (e.g., [abi:cxx11]). See here for a description of ABI tags:
161 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
163 Functions with a C++11 abi tag are demangled/displayed like this:
165 function[abi:cxx11](int)
168 You can now set a breakpoint on such functions simply as if they had
171 (gdb) b function(int)
173 Or if you need to disambiguate between tags, like:
175 (gdb) b function[abi:other_tag](int)
177 Tab completion was adjusted accordingly as well.
181 ** New events gdb.new_inferior, gdb.inferior_deleted, and
182 gdb.new_thread are emitted. See the manual for further
183 description of these.
185 ** A new function, "gdb.rbreak" has been added to the Python API.
186 This function allows the setting of a large number of breakpoints
187 via a regex pattern in Python. See the manual for further details.
189 ** Python breakpoints can now accept explicit locations. See the
190 manual for a further description of this feature.
193 * New features in the GDB remote stub, GDBserver
195 ** GDBserver is now able to start inferior processes with a
196 specified initial working directory.
198 The user can set the desired working directory to be used from
199 GDB using the new "set cwd" command.
201 ** New "--selftest" command line option runs some GDBserver self
202 tests. These self tests are disabled in releases.
204 ** On Unix systems, GDBserver now does globbing expansion and variable
205 substitution in inferior command line arguments.
207 This is done by starting inferiors using a shell, like GDB does.
208 See "set startup-with-shell" in the user manual for how to disable
209 this from GDB when using "target extended-remote". When using
210 "target remote", you can disable the startup with shell by using the
211 new "--no-startup-with-shell" GDBserver command line option.
213 ** On Unix systems, GDBserver now supports receiving environment
214 variables that are to be set or unset from GDB. These variables
215 will affect the environment to be passed to the inferior.
217 * When catching an Ada exception raised with a message, GDB now prints
218 the message in the catchpoint hit notification. In GDB/MI mode, that
219 information is provided as an extra field named "exception-message"
220 in the *stopped notification.
222 * Trait objects can now be inspected When debugging Rust code. This
223 requires compiler support which will appear in Rust 1.24.
227 QEnvironmentHexEncoded
228 Inform GDBserver of an environment variable that is to be passed to
229 the inferior when starting it.
232 Inform GDBserver of an environment variable that is to be unset
233 before starting the remote inferior.
236 Inform GDBserver that the environment should be reset (i.e.,
237 user-set environment variables should be unset).
240 Indicates whether the inferior must be started with a shell or not.
243 Tell GDBserver that the inferior to be started should use a specific
246 * The "maintenance print c-tdesc" command now takes an optional
247 argument which is the file name of XML target description.
249 * The "maintenance selftest" command now takes an optional argument to
250 filter the tests to be run.
252 * The "enable", and "disable" commands now accept a range of
253 breakpoint locations, e.g. "enable 1.3-5".
258 Set and show the current working directory for the inferior.
261 Set and show compilation command used for compiling and injecting code
262 with the 'compile' commands.
264 set debug separate-debug-file
265 show debug separate-debug-file
266 Control the display of debug output about separate debug file search.
268 set dump-excluded-mappings
269 show dump-excluded-mappings
270 Control whether mappings marked with the VM_DONTDUMP flag should be
271 dumped when generating a core file.
274 List the registered selftests.
277 Start the debugged program stopping at the first instruction.
280 Control display of debugging messages related to OpenRISC targets.
282 set|show print type nested-type-limit
283 Set and show the limit of nesting level for nested types that the
284 type printer will show.
286 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
289 * Safer/improved support for debugging with no debug info
291 GDB no longer assumes functions with no debug information return
294 This means that GDB now refuses to call such functions unless you
295 tell it the function's type, by either casting the call to the
296 declared return type, or by casting the function to a function
297 pointer of the right type, and calling that:
299 (gdb) p getenv ("PATH")
300 'getenv' has unknown return type; cast the call to its declared return type
301 (gdb) p (char *) getenv ("PATH")
302 $1 = 0x7fffffffe "/usr/local/bin:/"...
303 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
304 $2 = 0x7fffffffe "/usr/local/bin:/"...
306 Similarly, GDB no longer assumes that global variables with no debug
307 info have type 'int', and refuses to print the variable's value
308 unless you tell it the variable's type:
311 'var' has unknown type; cast it to its declared type
315 * New native configurations
317 FreeBSD/aarch64 aarch64*-*-freebsd*
318 FreeBSD/arm arm*-*-freebsd*
322 FreeBSD/aarch64 aarch64*-*-freebsd*
323 FreeBSD/arm arm*-*-freebsd*
324 OpenRISC ELF or1k*-*-elf
326 * Removed targets and native configurations
328 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
330 *** Changes in GDB 8.0
332 * GDB now supports access to the PKU register on GNU/Linux. The register is
333 added by the Memory Protection Keys for Userspace feature which will be
334 available in future Intel CPUs.
336 * GDB now supports C++11 rvalue references.
340 ** New functions to start, stop and access a running btrace recording.
341 ** Rvalue references are now supported in gdb.Type.
343 * GDB now supports recording and replaying rdrand and rdseed Intel 64
346 * Building GDB and GDBserver now requires a C++11 compiler.
348 For example, GCC 4.8 or later.
350 It is no longer possible to build GDB or GDBserver with a C
351 compiler. The --disable-build-with-cxx configure option has been
354 * Building GDB and GDBserver now requires GNU make >= 3.81.
356 It is no longer supported to build GDB or GDBserver with another
357 implementation of the make program or an earlier version of GNU make.
359 * Native debugging on MS-Windows supports command-line redirection
361 Command-line arguments used for starting programs on MS-Windows can
362 now include redirection symbols supported by native Windows shells,
363 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
364 as "run", "start", and "set args", as well as the corresponding MI
367 * Support for thread names on MS-Windows.
369 GDB now catches and handles the special exception that programs
370 running on MS-Windows use to assign names to threads in the
373 * Support for Java programs compiled with gcj has been removed.
375 * User commands now accept an unlimited number of arguments.
376 Previously, only up to 10 was accepted.
378 * The "eval" command now expands user-defined command arguments.
380 This makes it easier to process a variable number of arguments:
385 eval "print $arg%d", $i
390 * Target descriptions can now describe registers for sparc32 and sparc64.
392 * GDB now supports DWARF version 5 (debug information format).
393 Its .debug_names index is not yet supported.
395 * New native configurations
397 FreeBSD/mips mips*-*-freebsd
401 Synopsys ARC arc*-*-elf32
402 FreeBSD/mips mips*-*-freebsd
404 * Removed targets and native configurations
406 Alpha running FreeBSD alpha*-*-freebsd*
407 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
412 Erases all the flash memory regions reported by the target.
414 maint print arc arc-instruction address
415 Print internal disassembler information about instruction at a given address.
419 set disassembler-options
420 show disassembler-options
421 Controls the passing of target specific information to the disassembler.
422 If it is necessary to specify more than one disassembler option then
423 multiple options can be placed together into a comma separated list.
424 The default value is the empty string. Currently, the only supported
425 targets are ARM, PowerPC and S/390.
430 Erases all the flash memory regions reported by the target. This is
431 equivalent to the CLI command flash-erase.
433 -file-list-shared-libraries
434 List the shared libraries in the program. This is
435 equivalent to the CLI command "info shared".
438 Catchpoints stopping the program when Ada exceptions are
439 handled. This is equivalent to the CLI command "catch handlers".
441 *** Changes in GDB 7.12
443 * GDB and GDBserver now build with a C++ compiler by default.
445 The --enable-build-with-cxx configure option is now enabled by
446 default. One must now explicitly configure with
447 --disable-build-with-cxx in order to build with a C compiler. This
448 option will be removed in a future release.
450 * GDBserver now supports recording btrace without maintaining an active
453 * GDB now supports a negative repeat count in the 'x' command to examine
454 memory backward from the given address. For example:
457 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
458 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
459 (gdb) x/-5i 0x0000000000400580
460 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
461 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
462 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
463 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
464 0x40057b <main(int, char**)+25>:
465 callq 0x400536 <Func1(int, char const*)>
467 * Fortran: Support structures with fields of dynamic types and
468 arrays of dynamic types.
470 * The symbol dumping maintenance commands have new syntax.
471 maint print symbols [-pc address] [--] [filename]
472 maint print symbols [-objfile objfile] [-source source] [--] [filename]
473 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
474 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
475 maint print msymbols [-objfile objfile] [--] [filename]
477 * GDB now supports multibit bitfields and enums in target register
480 * New Python-based convenience function $_as_string(val), which returns
481 the textual representation of a value. This function is especially
482 useful to obtain the text label of an enum value.
484 * Intel MPX bound violation handling.
486 Segmentation faults caused by a Intel MPX boundary violation
487 now display the kind of violation (upper or lower), the memory
488 address accessed and the memory bounds, along with the usual
489 signal received and code location.
493 Program received signal SIGSEGV, Segmentation fault
494 Upper bound violation while accessing address 0x7fffffffc3b3
495 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
496 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
498 * Rust language support.
499 GDB now supports debugging programs written in the Rust programming
500 language. See https://www.rust-lang.org/ for more information about
503 * Support for running interpreters on specified input/output devices
505 GDB now supports a new mechanism that allows frontends to provide
506 fully featured GDB console views, as a better alternative to
507 building such views on top of the "-interpreter-exec console"
508 command. See the new "new-ui" command below. With that command,
509 frontends can now start GDB in the traditional command-line mode
510 running in an embedded terminal emulator widget, and create a
511 separate MI interpreter running on a specified i/o device. In this
512 way, GDB handles line editing, history, tab completion, etc. in the
513 console all by itself, and the GUI uses the separate MI interpreter
514 for its own control and synchronization, invisible to the command
517 * The "catch syscall" command catches groups of related syscalls.
519 The "catch syscall" command now supports catching a group of related
520 syscalls using the 'group:' or 'g:' prefix.
525 skip -gfile file-glob-pattern
526 skip -function function
527 skip -rfunction regular-expression
528 A generalized form of the skip command, with new support for
529 glob-style file names and regular expressions for function names.
530 Additionally, a file spec and a function spec may now be combined.
532 maint info line-table REGEXP
533 Display the contents of GDB's internal line table data struture.
536 Run any GDB unit tests that were compiled in.
539 Start a new user interface instance running INTERP as interpreter,
540 using the TTY file for input/output.
544 ** gdb.Breakpoint objects have a new attribute "pending", which
545 indicates whether the breakpoint is pending.
546 ** Three new breakpoint-related events have been added:
547 gdb.breakpoint_created, gdb.breakpoint_modified, and
548 gdb.breakpoint_deleted.
551 Signal ("set") the given MS-Windows event object. This is used in
552 conjunction with the Windows JIT debugging (AeDebug) support, where
553 the OS suspends a crashing process until a debugger can attach to
554 it. Resuming the crashing process, in order to debug it, is done by
557 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
558 was added in GDBserver, including JIT compiling fast tracepoint's
559 conditional expression bytecode into native code.
561 * Support for various remote target protocols and ROM monitors has
564 target m32rsdi Remote M32R debugging over SDI
565 target mips MIPS remote debugging protocol
566 target pmon PMON ROM monitor
567 target ddb NEC's DDB variant of PMON for Vr4300
568 target rockhopper NEC RockHopper variant of PMON
569 target lsi LSI variant of PMO
571 * Support for tracepoints and fast tracepoints on powerpc-linux,
572 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
573 including JIT compiling fast tracepoint's conditional expression
574 bytecode into native code.
576 * MI async record =record-started now includes the method and format used for
577 recording. For example:
579 =record-started,thread-group="i1",method="btrace",format="bts"
581 * MI async record =thread-selected now includes the frame field. For example:
583 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
587 Andes NDS32 nds32*-*-elf
589 *** Changes in GDB 7.11
591 * GDB now supports debugging kernel-based threads on FreeBSD.
593 * Per-inferior thread numbers
595 Thread numbers are now per inferior instead of global. If you're
596 debugging multiple inferiors, GDB displays thread IDs using a
597 qualified INF_NUM.THR_NUM form. For example:
601 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
602 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
603 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
604 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
606 As consequence, thread numbers as visible in the $_thread
607 convenience variable and in Python's InferiorThread.num attribute
608 are no longer unique between inferiors.
610 GDB now maintains a second thread ID per thread, referred to as the
611 global thread ID, which is the new equivalent of thread numbers in
612 previous releases. See also $_gthread below.
614 For backwards compatibility, MI's thread IDs always refer to global
617 * Commands that accept thread IDs now accept the qualified
618 INF_NUM.THR_NUM form as well. For example:
621 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
624 * In commands that accept a list of thread IDs, you can now refer to
625 all threads of an inferior using a star wildcard. GDB accepts
626 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
627 refer to all threads of the current inferior. For example, "info
630 * You can use "info threads -gid" to display the global thread ID of
633 * The new convenience variable $_gthread holds the global number of
636 * The new convenience variable $_inferior holds the number of the
639 * GDB now displays the ID and name of the thread that hit a breakpoint
640 or received a signal, if your program is multi-threaded. For
643 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
644 Thread 1 "main" received signal SIGINT, Interrupt.
646 * Record btrace now supports non-stop mode.
648 * Support for tracepoints on aarch64-linux was added in GDBserver.
650 * The 'record instruction-history' command now indicates speculative execution
651 when using the Intel Processor Trace recording format.
653 * GDB now allows users to specify explicit locations, bypassing
654 the linespec parser. This feature is also available to GDB/MI
657 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
658 GDB now is able to debug both AArch64 applications and ARM applications
661 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
662 including JIT compiling fast tracepoint's conditional expression bytecode
665 * GDB now supports displaced stepping on AArch64 GNU/Linux.
667 * "info threads", "info inferiors", "info display", "info checkpoints"
668 and "maint info program-spaces" now list the corresponding items in
669 ascending ID order, for consistency with all other "info" commands.
671 * In Ada, the overloads selection menu has been enhanced to display the
672 parameter types and the return types for the matching overloaded subprograms.
676 maint set target-non-stop (on|off|auto)
677 maint show target-non-stop
678 Control whether GDB targets always operate in non-stop mode even if
679 "set non-stop" is "off". The default is "auto", meaning non-stop
680 mode is enabled if supported by the target.
682 maint set bfd-sharing
683 maint show bfd-sharing
684 Control the reuse of bfd objects.
688 Control display of debugging info regarding bfd caching.
692 Control display of debugging info regarding FreeBSD threads.
694 set remote multiprocess-extensions-packet
695 show remote multiprocess-extensions-packet
696 Set/show the use of the remote protocol multiprocess extensions.
698 set remote thread-events
699 show remote thread-events
700 Set/show the use of thread create/exit events.
702 set ada print-signatures on|off
703 show ada print-signatures"
704 Control whether parameter types and return types are displayed in overloads
705 selection menus. It is activaled (@code{on}) by default.
709 Controls the maximum size of memory, in bytes, that GDB will
710 allocate for value contents. Prevents incorrect programs from
711 causing GDB to allocate overly large buffers. Default is 64k.
713 * The "disassemble" command accepts a new modifier: /s.
714 It prints mixed source+disassembly like /m with two differences:
715 - disassembled instructions are now printed in program order, and
716 - and source for all relevant files is now printed.
717 The "/m" option is now considered deprecated: its "source-centric"
718 output hasn't proved useful in practice.
720 * The "record instruction-history" command accepts a new modifier: /s.
721 It behaves exactly like /m and prints mixed source+disassembly.
723 * The "set scheduler-locking" command supports a new mode "replay".
724 It behaves like "off" in record mode and like "on" in replay mode.
726 * Support for various ROM monitors has been removed:
728 target dbug dBUG ROM monitor for Motorola ColdFire
729 target picobug Motorola picobug monitor
730 target dink32 DINK32 ROM monitor for PowerPC
731 target m32r Renesas M32R/D ROM monitor
732 target mon2000 mon2000 ROM monitor
733 target ppcbug PPCBUG ROM monitor for PowerPC
735 * Support for reading/writing memory and extracting values on architectures
736 whose memory is addressable in units of any integral multiple of 8 bits.
739 Allows to break when an Ada exception is handled.
744 Indicates that an exec system call was executed.
746 exec-events feature in qSupported
747 The qSupported packet allows GDB to request support for exec
748 events using the new 'gdbfeature' exec-event, and the qSupported
749 response can contain the corresponding 'stubfeature'. Set and
750 show commands can be used to display whether these features are enabled.
753 Equivalent to interrupting with the ^C character, but works in
756 thread created stop reason (T05 create:...)
757 Indicates that the thread was just created and is stopped at entry.
759 thread exit stop reply (w exitcode;tid)
760 Indicates that the thread has terminated.
763 Enables/disables thread create and exit event reporting. For
764 example, this is used in non-stop mode when GDB stops a set of
765 threads and synchronously waits for the their corresponding stop
766 replies. Without exit events, if one of the threads exits, GDB
767 would hang forever not knowing that it should no longer expect a
768 stop for that same thread.
771 Indicates that there are no resumed threads left in the target (all
772 threads are stopped). The remote stub reports support for this stop
773 reply to GDB's qSupported query.
776 Enables/disables catching syscalls from the inferior process.
777 The remote stub reports support for this packet to GDB's qSupported query.
779 syscall_entry stop reason
780 Indicates that a syscall was just called.
782 syscall_return stop reason
783 Indicates that a syscall just returned.
785 * Extended-remote exec events
787 ** GDB now has support for exec events on extended-remote Linux targets.
788 For such targets with Linux kernels 2.5.46 and later, this enables
789 follow-exec-mode and exec catchpoints.
791 set remote exec-event-feature-packet
792 show remote exec-event-feature-packet
793 Set/show the use of the remote exec event feature.
795 * Thread names in remote protocol
797 The reply to qXfer:threads:read may now include a name attribute for each
800 * Target remote mode fork and exec events
802 ** GDB now has support for fork and exec events on target remote mode
803 Linux targets. For such targets with Linux kernels 2.5.46 and later,
804 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
805 fork and exec catchpoints.
807 * Remote syscall events
809 ** GDB now has support for catch syscall on remote Linux targets,
810 currently enabled on x86/x86_64 architectures.
812 set remote catch-syscall-packet
813 show remote catch-syscall-packet
814 Set/show the use of the remote catch syscall feature.
818 ** The -var-set-format command now accepts the zero-hexadecimal
819 format. It outputs data in hexadecimal format with zero-padding on the
824 ** gdb.InferiorThread objects have a new attribute "global_num",
825 which refers to the thread's global thread ID. The existing
826 "num" attribute now refers to the thread's per-inferior number.
827 See "Per-inferior thread numbers" above.
828 ** gdb.InferiorThread objects have a new attribute "inferior", which
829 is the Inferior object the thread belongs to.
831 *** Changes in GDB 7.10
833 * Support for process record-replay and reverse debugging on aarch64*-linux*
834 targets has been added. GDB now supports recording of A64 instruction set
835 including advance SIMD instructions.
837 * Support for Sun's version of the "stabs" debug file format has been removed.
839 * GDB now honors the content of the file /proc/PID/coredump_filter
840 (PID is the process ID) on GNU/Linux systems. This file can be used
841 to specify the types of memory mappings that will be included in a
842 corefile. For more information, please refer to the manual page of
843 "core(5)". GDB also has a new command: "set use-coredump-filter
844 on|off". It allows to set whether GDB will read the content of the
845 /proc/PID/coredump_filter file when generating a corefile.
847 * The "info os" command on GNU/Linux can now display information on
849 "info os cpus" Listing of all cpus/cores on the system
851 * GDB has two new commands: "set serial parity odd|even|none" and
852 "show serial parity". These allows to set or show parity for the
855 * The "info source" command now displays the producer string if it was
856 present in the debug info. This typically includes the compiler version
857 and may include things like its command line arguments.
859 * The "info dll", an alias of the "info sharedlibrary" command,
860 is now available on all platforms.
862 * Directory names supplied to the "set sysroot" commands may be
863 prefixed with "target:" to tell GDB to access shared libraries from
864 the target system, be it local or remote. This replaces the prefix
865 "remote:". The default sysroot has been changed from "" to
866 "target:". "remote:" is automatically converted to "target:" for
867 backward compatibility.
869 * The system root specified by "set sysroot" will be prepended to the
870 filename of the main executable (if reported to GDB as absolute by
871 the operating system) when starting processes remotely, and when
872 attaching to already-running local or remote processes.
874 * GDB now supports automatic location and retrieval of executable
875 files from remote targets. Remote debugging can now be initiated
876 using only a "target remote" or "target extended-remote" command
877 (no "set sysroot" or "file" commands are required). See "New remote
880 * The "dump" command now supports verilog hex format.
882 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
884 * On GNU/Linux, GDB and gdbserver are now able to access executable
885 and shared library files without a "set sysroot" command when
886 attaching to processes running in different mount namespaces from
887 the debugger. This makes it possible to attach to processes in
888 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
889 See "New remote packets" below.
891 * The "tui reg" command now provides completion for all of the
892 available register groups, including target specific groups.
894 * The HISTSIZE environment variable is no longer read when determining
895 the size of GDB's command history. GDB now instead reads the dedicated
896 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
897 disables truncation of command history. Non-numeric values of GDBHISTSIZE
902 ** Memory ports can now be unbuffered.
906 ** gdb.Objfile objects have a new attribute "username",
907 which is the name of the objfile as specified by the user,
908 without, for example, resolving symlinks.
909 ** You can now write frame unwinders in Python.
910 ** gdb.Type objects have a new method "optimized_out",
911 returning optimized out gdb.Value instance of this type.
912 ** gdb.Value objects have new methods "reference_value" and
913 "const_value" which return a reference to the value and a
914 "const" version of the value respectively.
918 maint print symbol-cache
919 Print the contents of the symbol cache.
921 maint print symbol-cache-statistics
922 Print statistics of symbol cache usage.
924 maint flush-symbol-cache
925 Flush the contents of the symbol cache.
929 Start branch trace recording using Branch Trace Store (BTS) format.
932 Evaluate expression by using the compiler and print result.
936 Explicit commands for enabling and disabling tui mode.
939 set mpx bound on i386 and amd64
940 Support for bound table investigation on Intel MPX enabled applications.
944 Start branch trace recording using Intel Processor Trace format.
947 Print information about branch tracing internals.
949 maint btrace packet-history
950 Print the raw branch tracing data.
952 maint btrace clear-packet-history
953 Discard the stored raw branch tracing data.
956 Discard all branch tracing data. It will be fetched and processed
957 anew by the next "record" command.
962 Renamed from "set debug dwarf2-die".
964 Renamed from "show debug dwarf2-die".
967 Renamed from "set debug dwarf2-read".
968 show debug dwarf-read
969 Renamed from "show debug dwarf2-read".
971 maint set dwarf always-disassemble
972 Renamed from "maint set dwarf2 always-disassemble".
973 maint show dwarf always-disassemble
974 Renamed from "maint show dwarf2 always-disassemble".
976 maint set dwarf max-cache-age
977 Renamed from "maint set dwarf2 max-cache-age".
978 maint show dwarf max-cache-age
979 Renamed from "maint show dwarf2 max-cache-age".
982 show debug dwarf-line
983 Control display of debugging info regarding DWARF line processing.
987 Set the maximum number of candidates to be considered during
988 completion. The default value is 200. This limit allows GDB
989 to avoid generating large completion lists, the computation of
990 which can cause the debugger to become temporarily unresponsive.
992 set history remove-duplicates
993 show history remove-duplicates
994 Control the removal of duplicate history entries.
996 maint set symbol-cache-size
997 maint show symbol-cache-size
998 Control the size of the symbol cache.
1000 set|show record btrace bts buffer-size
1001 Set and show the size of the ring buffer used for branch tracing in
1003 The obtained size may differ from the requested size. Use "info
1004 record" to see the obtained buffer size.
1006 set debug linux-namespaces
1007 show debug linux-namespaces
1008 Control display of debugging info regarding Linux namespaces.
1010 set|show record btrace pt buffer-size
1011 Set and show the size of the ring buffer used for branch tracing in
1012 Intel Processor Trace format.
1013 The obtained size may differ from the requested size. Use "info
1014 record" to see the obtained buffer size.
1016 maint set|show btrace pt skip-pad
1017 Set and show whether PAD packets are skipped when computing the
1020 * The command 'thread apply all' can now support new option '-ascending'
1021 to call its specified command for all threads in ascending order.
1023 * Python/Guile scripting
1025 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1026 special section named `.debug_gdb_scripts'.
1028 * New remote packets
1030 qXfer:btrace-conf:read
1031 Return the branch trace configuration for the current thread.
1033 Qbtrace-conf:bts:size
1034 Set the requested ring buffer size for branch tracing in BTS format.
1037 Enable Intel Procesor Trace-based branch tracing for the current
1038 process. The remote stub reports support for this packet to GDB's
1041 Qbtrace-conf:pt:size
1042 Set the requested ring buffer size for branch tracing in Intel Processor
1046 Indicates a memory breakpoint instruction was executed, irrespective
1047 of whether it was GDB that planted the breakpoint or the breakpoint
1048 is hardcoded in the program. This is required for correct non-stop
1052 Indicates the target stopped for a hardware breakpoint. This is
1053 required for correct non-stop mode operation.
1056 Return information about files on the remote system.
1058 qXfer:exec-file:read
1059 Return the full absolute name of the file that was executed to
1060 create a process running on the remote system.
1063 Select the filesystem on which vFile: operations with filename
1064 arguments will operate. This is required for GDB to be able to
1065 access files on remote targets where the remote stub does not
1066 share a common filesystem with the inferior(s).
1069 Indicates that a fork system call was executed.
1072 Indicates that a vfork system call was executed.
1074 vforkdone stop reason
1075 Indicates that a vfork child of the specified process has executed
1076 an exec or exit, allowing the vfork parent to resume execution.
1078 fork-events and vfork-events features in qSupported
1079 The qSupported packet allows GDB to request support for fork and
1080 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1081 and the qSupported response can contain the corresponding
1082 'stubfeatures'. Set and show commands can be used to display
1083 whether these features are enabled.
1085 * Extended-remote fork events
1087 ** GDB now has support for fork events on extended-remote Linux
1088 targets. For targets with Linux kernels 2.5.60 and later, this
1089 enables follow-fork-mode and detach-on-fork for both fork and
1090 vfork, as well as fork and vfork catchpoints.
1092 * The info record command now shows the recording format and the
1093 branch tracing configuration for the current thread when using
1094 the btrace record target.
1095 For the BTS format, it shows the ring buffer size.
1097 * GDB now has support for DTrace USDT (Userland Static Defined
1098 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1100 * GDB now supports access to vector registers on S/390 GNU/Linux
1103 * Removed command line options
1105 -xdb HP-UX XDB compatibility mode.
1107 * Removed targets and native configurations
1109 HP/PA running HP-UX hppa*-*-hpux*
1110 Itanium running HP-UX ia64-*-hpux*
1112 * New configure options
1115 This configure option allows the user to build GDB with support for
1116 Intel Processor Trace (default: auto). This requires libipt.
1118 --with-libipt-prefix=PATH
1119 Specify the path to the version of libipt that GDB should use.
1120 $PATH/include should contain the intel-pt.h header and
1121 $PATH/lib should contain the libipt.so library.
1123 *** Changes in GDB 7.9.1
1127 ** Xmethods can now specify a result type.
1129 *** Changes in GDB 7.9
1131 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1135 ** You can now access frame registers from Python scripts.
1136 ** New attribute 'producer' for gdb.Symtab objects.
1137 ** gdb.Objfile objects have a new attribute "progspace",
1138 which is the gdb.Progspace object of the containing program space.
1139 ** gdb.Objfile objects have a new attribute "owner".
1140 ** gdb.Objfile objects have a new attribute "build_id",
1141 which is the build ID generated when the file was built.
1142 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1143 ** A new event "gdb.clear_objfiles" has been added, triggered when
1144 selecting a new file to debug.
1145 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1146 ** New function gdb.lookup_objfile.
1148 New events which are triggered when GDB modifies the state of the
1151 ** gdb.events.inferior_call_pre: Function call is about to be made.
1152 ** gdb.events.inferior_call_post: Function call has just been made.
1153 ** gdb.events.memory_changed: A memory location has been altered.
1154 ** gdb.events.register_changed: A register has been altered.
1156 * New Python-based convenience functions:
1158 ** $_caller_is(name [, number_of_frames])
1159 ** $_caller_matches(regexp [, number_of_frames])
1160 ** $_any_caller_is(name [, number_of_frames])
1161 ** $_any_caller_matches(regexp [, number_of_frames])
1163 * GDB now supports the compilation and injection of source code into
1164 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1165 to compile the source code to object code, and if successful, inject
1166 and execute that code within the current context of the inferior.
1167 Currently the C language is supported. The commands used to
1168 interface with this new feature are:
1170 compile code [-raw|-r] [--] [source code]
1171 compile file [-raw|-r] filename
1175 demangle [-l language] [--] name
1176 Demangle "name" in the specified language, or the current language
1177 if elided. This command is renamed from the "maint demangle" command.
1178 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1179 as "maint demangler-warning".
1181 queue-signal signal-name-or-number
1182 Queue a signal to be delivered to the thread when it is resumed.
1184 add-auto-load-scripts-directory directory
1185 Add entries to the list of directories from which to load auto-loaded
1188 maint print user-registers
1189 List all currently available "user" registers.
1191 compile code [-r|-raw] [--] [source code]
1192 Compile, inject, and execute in the inferior the executable object
1193 code produced by compiling the provided source code.
1195 compile file [-r|-raw] filename
1196 Compile and inject into the inferior the executable object code
1197 produced by compiling the source code stored in the filename
1200 * On resume, GDB now always passes the signal the program had stopped
1201 for to the thread the signal was sent to, even if the user changed
1202 threads before resuming. Previously GDB would often (but not
1203 always) deliver the signal to the thread that happens to be current
1206 * Conversely, the "signal" command now consistently delivers the
1207 requested signal to the current thread. GDB now asks for
1208 confirmation if the program had stopped for a signal and the user
1209 switched threads meanwhile.
1211 * "breakpoint always-inserted" modes "off" and "auto" merged.
1213 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1214 won't remove breakpoints from the target until all threads stop,
1215 even in non-stop mode. The "auto" mode has been removed, and "off"
1216 is now the default mode.
1220 set debug symbol-lookup
1221 show debug symbol-lookup
1222 Control display of debugging info regarding symbol lookup.
1226 ** The -list-thread-groups command outputs an exit-code field for
1227 inferiors that have exited.
1231 MIPS SDE mips*-sde*-elf*
1235 Support for these obsolete configurations has been removed.
1237 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1238 SGI Irix-5.x mips-*-irix5*
1239 SGI Irix-6.x mips-*-irix6*
1240 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1241 VAX running Ultrix vax-*-ultrix*
1243 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1244 and "assf"), have been removed. Use the "sharedlibrary" command, or
1245 its alias "share", instead.
1247 *** Changes in GDB 7.8
1249 * New command line options
1252 This is an alias for the --data-directory option.
1254 * GDB supports printing and modifying of variable length automatic arrays
1255 as specified in ISO C99.
1257 * The ARM simulator now supports instruction level tracing
1258 with or without disassembly.
1262 GDB now has support for scripting using Guile. Whether this is
1263 available is determined at configure time.
1264 Guile version 2.0 or greater is required.
1265 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1267 * New commands (for set/show, see "New options" below)
1271 Invoke CODE by passing it to the Guile interpreter.
1275 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1277 info auto-load guile-scripts [regexp]
1278 Print the list of automatically loaded Guile scripts.
1280 * The source command is now capable of sourcing Guile scripts.
1281 This feature is dependent on the debugger being built with Guile support.
1285 set print symbol-loading (off|brief|full)
1286 show print symbol-loading
1287 Control whether to print informational messages when loading symbol
1288 information for a file. The default is "full", but when debugging
1289 programs with large numbers of shared libraries the amount of output
1290 becomes less useful.
1292 set guile print-stack (none|message|full)
1293 show guile print-stack
1294 Show a stack trace when an error is encountered in a Guile script.
1296 set auto-load guile-scripts (on|off)
1297 show auto-load guile-scripts
1298 Control auto-loading of Guile script files.
1300 maint ada set ignore-descriptive-types (on|off)
1301 maint ada show ignore-descriptive-types
1302 Control whether the debugger should ignore descriptive types in Ada
1303 programs. The default is not to ignore the descriptive types. See
1304 the user manual for more details on descriptive types and the intended
1305 usage of this option.
1307 set auto-connect-native-target
1309 Control whether GDB is allowed to automatically connect to the
1310 native target for the run, attach, etc. commands when not connected
1311 to any target yet. See also "target native" below.
1313 set record btrace replay-memory-access (read-only|read-write)
1314 show record btrace replay-memory-access
1315 Control what memory accesses are allowed during replay.
1317 maint set target-async (on|off)
1318 maint show target-async
1319 This controls whether GDB targets operate in synchronous or
1320 asynchronous mode. Normally the default is asynchronous, if it is
1321 available; but this can be changed to more easily debug problems
1322 occurring only in synchronous mode.
1324 set mi-async (on|off)
1326 Control whether MI asynchronous mode is preferred. This supersedes
1327 "set target-async" of previous GDB versions.
1329 * "set target-async" is deprecated as a CLI option and is now an alias
1330 for "set mi-async" (only puts MI into async mode).
1332 * Background execution commands (e.g., "c&", "s&", etc.) are now
1333 possible ``out of the box'' if the target supports them. Previously
1334 the user would need to explicitly enable the possibility with the
1335 "set target-async on" command.
1337 * New features in the GDB remote stub, GDBserver
1339 ** New option --debug-format=option1[,option2,...] allows one to add
1340 additional text to each output. At present only timestamps
1341 are supported: --debug-format=timestamps.
1342 Timestamps can also be turned on with the
1343 "monitor set debug-format timestamps" command from GDB.
1345 * The 'record instruction-history' command now starts counting instructions
1346 at one. This also affects the instruction ranges reported by the
1347 'record function-call-history' command when given the /i modifier.
1349 * The command 'record function-call-history' supports a new modifier '/c' to
1350 indent the function names based on their call stack depth.
1351 The fields for the '/i' and '/l' modifier have been reordered.
1352 The source line range is now prefixed with 'at'.
1353 The instruction range is now prefixed with 'inst'.
1354 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1355 "record instruction-history" and "list" commands.
1357 * The ranges given as arguments to the 'record function-call-history' and
1358 'record instruction-history' commands are now inclusive.
1360 * The btrace record target now supports the 'record goto' command.
1361 For locations inside the execution trace, the back trace is computed
1362 based on the information stored in the execution trace.
1364 * The btrace record target supports limited reverse execution and replay.
1365 The target does not record data and therefore does not allow reading
1366 memory or registers.
1368 * The "catch syscall" command now works on s390*-linux* targets.
1370 * The "compare-sections" command is no longer specific to target
1371 remote. It now works with all targets.
1373 * All native targets are now consistently called "native".
1374 Consequently, the "target child", "target GNU", "target djgpp",
1375 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1376 commands have been replaced with "target native". The QNX/NTO port
1377 leaves the "procfs" target in place and adds a "native" target for
1378 consistency with other ports. The impact on users should be minimal
1379 as these commands previously either throwed an error, or were
1380 no-ops. The target's name is visible in the output of the following
1381 commands: "help target", "info target", "info files", "maint print
1384 * The "target native" command now connects to the native target. This
1385 can be used to launch native programs even when "set
1386 auto-connect-native-target" is set to off.
1388 * GDB now supports access to Intel MPX registers on GNU/Linux.
1390 * Support for Intel AVX-512 registers on GNU/Linux.
1391 Support displaying and modifying Intel AVX-512 registers
1392 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1394 * New remote packets
1396 qXfer:btrace:read's annex
1397 The qXfer:btrace:read packet supports a new annex 'delta' to read
1398 branch trace incrementally.
1402 ** Valid Python operations on gdb.Value objects representing
1403 structs/classes invoke the corresponding overloaded operators if
1405 ** New `Xmethods' feature in the Python API. Xmethods are
1406 additional methods or replacements for existing methods of a C++
1407 class. This feature is useful for those cases where a method
1408 defined in C++ source code could be inlined or optimized out by
1409 the compiler, making it unavailable to GDB.
1412 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1414 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1415 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1416 its alias "share", instead.
1418 * The commands "set remotebaud" and "show remotebaud" are no longer
1419 supported. Use "set serial baud" and "show serial baud" (respectively)
1424 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1425 target-async". The latter is left as a deprecated alias of the
1426 former for backward compatibility. If the target supports it,
1427 CLI background execution commands are now always possible by
1428 default, independently of whether the frontend stated a
1429 preference for asynchronous execution with "-gdb-set mi-async".
1430 Previously "-gdb-set target-async off" affected both MI execution
1431 commands and CLI execution commands.
1433 *** Changes in GDB 7.7
1435 * Improved support for process record-replay and reverse debugging on
1436 arm*-linux* targets. Support for thumb32 and syscall instruction
1437 recording has been added.
1439 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1441 * GDB now supports Fission DWP file format version 2.
1442 http://gcc.gnu.org/wiki/DebugFission
1444 * New convenience function "$_isvoid", to check whether an expression
1445 is void. A void expression is an expression where the type of the
1446 result is "void". For example, some convenience variables may be
1447 "void" when evaluated (e.g., "$_exitcode" before the execution of
1448 the program being debugged; or an undefined convenience variable).
1449 Another example, when calling a function whose return type is
1452 * The "maintenance print objfiles" command now takes an optional regexp.
1454 * The "catch syscall" command now works on arm*-linux* targets.
1456 * GDB now consistently shows "<not saved>" when printing values of
1457 registers the debug info indicates have not been saved in the frame
1458 and there's nowhere to retrieve them from
1459 (callee-saved/call-clobbered registers):
1464 (gdb) info registers rax
1467 Before, the former would print "<optimized out>", and the latter
1468 "*value not available*".
1470 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1475 ** Frame filters and frame decorators have been added.
1476 ** Temporary breakpoints are now supported.
1477 ** Line tables representation has been added.
1478 ** New attribute 'parent_type' for gdb.Field objects.
1479 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1480 ** New attribute 'name' for gdb.Type objects.
1484 Nios II ELF nios2*-*-elf
1485 Nios II GNU/Linux nios2*-*-linux
1486 Texas Instruments MSP430 msp430*-*-elf
1488 * Removed native configurations
1490 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1491 been removed. ELF variants of these configurations are kept supported.
1493 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1494 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1495 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1496 i[34567]86-*-openbsd3.[0-3]
1497 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1498 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1499 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1503 Like "catch throw", but catches a re-thrown exception.
1504 maint check-psymtabs
1505 Renamed from old "maint check-symtabs".
1507 Perform consistency checks on symtabs.
1508 maint expand-symtabs
1509 Expand symtabs matching an optional regexp.
1512 Display the details of GDB configure-time options.
1514 maint set|show per-command
1515 maint set|show per-command space
1516 maint set|show per-command time
1517 maint set|show per-command symtab
1518 Enable display of per-command gdb resource usage.
1520 remove-symbol-file FILENAME
1521 remove-symbol-file -a ADDRESS
1522 Remove a symbol file added via add-symbol-file. The file to remove
1523 can be identified by its filename or by an address that lies within
1524 the boundaries of this symbol file in memory.
1527 info exceptions REGEXP
1528 Display the list of Ada exceptions defined in the program being
1529 debugged. If provided, only the exceptions whose names match REGEXP
1534 set debug symfile off|on
1536 Control display of debugging info regarding reading symbol files and
1537 symbol tables within those files
1539 set print raw frame-arguments
1540 show print raw frame-arguments
1541 Set/show whether to print frame arguments in raw mode,
1542 disregarding any defined pretty-printers.
1544 set remote trace-status-packet
1545 show remote trace-status-packet
1546 Set/show the use of remote protocol qTStatus packet.
1550 Control display of debugging messages related to Nios II targets.
1554 Control whether target-assisted range stepping is enabled.
1556 set startup-with-shell
1557 show startup-with-shell
1558 Specifies whether Unix child processes are started via a shell or
1563 Use the target memory cache for accesses to the code segment. This
1564 improves performance of remote debugging (particularly disassembly).
1566 * You can now use a literal value 'unlimited' for options that
1567 interpret 0 or -1 as meaning "unlimited". E.g., "set
1568 trace-buffer-size unlimited" is now an alias for "set
1569 trace-buffer-size -1" and "set height unlimited" is now an alias for
1572 * The "set debug symtab-create" debugging option of GDB has been changed to
1573 accept a verbosity level. 0 means "off", 1 provides basic debugging
1574 output, and values of 2 or greater provides more verbose output.
1576 * New command-line options
1578 Display the details of GDB configure-time options.
1580 * The command 'tsave' can now support new option '-ctf' to save trace
1581 buffer in Common Trace Format.
1583 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1586 * GDB now implements the the C++ 'typeid' operator.
1588 * The new convenience variable $_exception holds the exception being
1589 thrown or caught at an exception-related catchpoint.
1591 * The exception-related catchpoints, like "catch throw", now accept a
1592 regular expression which can be used to filter exceptions by type.
1594 * The new convenience variable $_exitsignal is automatically set to
1595 the terminating signal number when the program being debugged dies
1596 due to an uncaught signal.
1600 ** All MI commands now accept an optional "--language" option.
1601 Support for this feature can be verified by using the "-list-features"
1602 command, which should contain "language-option".
1604 ** The new command -info-gdb-mi-command allows the user to determine
1605 whether a GDB/MI command is supported or not.
1607 ** The "^error" result record returned when trying to execute an undefined
1608 GDB/MI command now provides a variable named "code" whose content is the
1609 "undefined-command" error code. Support for this feature can be verified
1610 by using the "-list-features" command, which should contain
1611 "undefined-command-error-code".
1613 ** The -trace-save MI command can optionally save trace buffer in Common
1616 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1618 ** The command -data-list-register-values now accepts an optional
1619 "--skip-unavailable" option. When used, only the available registers
1622 ** The new command -trace-frame-collected dumps collected variables,
1623 computed expressions, tvars, memory and registers in a traceframe.
1625 ** The commands -stack-list-locals, -stack-list-arguments and
1626 -stack-list-variables now accept an option "--skip-unavailable".
1627 When used, only the available locals or arguments are displayed.
1629 ** The -exec-run command now accepts an optional "--start" option.
1630 When used, the command follows the same semantics as the "start"
1631 command, stopping the program's execution at the start of its
1632 main subprogram. Support for this feature can be verified using
1633 the "-list-features" command, which should contain
1634 "exec-run-start-option".
1636 ** The new commands -catch-assert and -catch-exceptions insert
1637 catchpoints stopping the program when Ada exceptions are raised.
1639 ** The new command -info-ada-exceptions provides the equivalent of
1640 the new "info exceptions" command.
1642 * New system-wide configuration scripts
1643 A GDB installation now provides scripts suitable for use as system-wide
1644 configuration scripts for the following systems:
1648 * GDB now supports target-assigned range stepping with remote targets.
1649 This improves the performance of stepping source lines by reducing
1650 the number of control packets from/to GDB. See "New remote packets"
1653 * GDB now understands the element 'tvar' in the XML traceframe info.
1654 It has the id of the collected trace state variables.
1656 * On S/390 targets that provide the transactional-execution feature,
1657 the program interruption transaction diagnostic block (TDB) is now
1658 represented as a number of additional "registers" in GDB.
1660 * New remote packets
1664 The vCont packet supports a new 'r' action, that tells the remote
1665 stub to step through an address range itself, without GDB
1666 involvemement at each single-step.
1668 qXfer:libraries-svr4:read's annex
1669 The previously unused annex of the qXfer:libraries-svr4:read packet
1670 is now used to support passing an argument list. The remote stub
1671 reports support for this argument list to GDB's qSupported query.
1672 The defined arguments are "start" and "prev", used to reduce work
1673 necessary for library list updating, resulting in significant
1676 * New features in the GDB remote stub, GDBserver
1678 ** GDBserver now supports target-assisted range stepping. Currently
1679 enabled on x86/x86_64 GNU/Linux targets.
1681 ** GDBserver now adds element 'tvar' in the XML in the reply to
1682 'qXfer:traceframe-info:read'. It has the id of the collected
1683 trace state variables.
1685 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1688 * New 'z' formatter for printing and examining memory, this displays the
1689 value as hexadecimal zero padded on the left to the size of the type.
1691 * GDB can now use Windows x64 unwinding data.
1693 * The "set remotebaud" command has been replaced by "set serial baud".
1694 Similarly, "show remotebaud" has been replaced by "show serial baud".
1695 The "set remotebaud" and "show remotebaud" commands are still available
1696 to provide backward compatibility with older versions of GDB.
1698 *** Changes in GDB 7.6
1700 * Target record has been renamed to record-full.
1701 Record/replay is now enabled with the "record full" command.
1702 This also affects settings that are associated with full record/replay
1703 that have been moved from "set/show record" to "set/show record full":
1705 set|show record full insn-number-max
1706 set|show record full stop-at-limit
1707 set|show record full memory-query
1709 * A new record target "record-btrace" has been added. The new target
1710 uses hardware support to record the control-flow of a process. It
1711 does not support replaying the execution, but it implements the
1712 below new commands for investigating the recorded execution log.
1713 This new recording method can be enabled using:
1717 The "record-btrace" target is only available on Intel Atom processors
1718 and requires a Linux kernel 2.6.32 or later.
1720 * Two new commands have been added for record/replay to give information
1721 about the recorded execution without having to replay the execution.
1722 The commands are only supported by "record btrace".
1724 record instruction-history prints the execution history at
1725 instruction granularity
1727 record function-call-history prints the execution history at
1728 function granularity
1730 * New native configurations
1732 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1733 FreeBSD/powerpc powerpc*-*-freebsd
1734 x86_64/Cygwin x86_64-*-cygwin*
1735 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1739 ARM AArch64 aarch64*-*-elf
1740 ARM AArch64 GNU/Linux aarch64*-*-linux
1741 Lynx 178 PowerPC powerpc-*-lynx*178
1742 x86_64/Cygwin x86_64-*-cygwin*
1743 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1745 * If the configured location of system.gdbinit file (as given by the
1746 --with-system-gdbinit option at configure time) is in the
1747 data-directory (as specified by --with-gdb-datadir at configure
1748 time) or in one of its subdirectories, then GDB will look for the
1749 system-wide init file in the directory specified by the
1750 --data-directory command-line option.
1752 * New command line options:
1754 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1755 other initialization files, unlike -nx which disables all of them.
1757 * Removed command line options
1759 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1762 * The 'ptype' and 'whatis' commands now accept an argument to control
1765 * 'info proc' now works on some core files.
1769 ** Vectors can be created with gdb.Type.vector.
1771 ** Python's atexit.register now works in GDB.
1773 ** Types can be pretty-printed via a Python API.
1775 ** Python 3 is now supported (in addition to Python 2.4 or later)
1777 ** New class gdb.Architecture exposes GDB's internal representation
1778 of architecture in the Python API.
1780 ** New method Frame.architecture returns the gdb.Architecture object
1781 corresponding to the frame's architecture.
1783 * New Python-based convenience functions:
1785 ** $_memeq(buf1, buf2, length)
1786 ** $_streq(str1, str2)
1788 ** $_regex(str, regex)
1790 * The 'cd' command now defaults to using '~' (the home directory) if not
1793 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1794 default for GCC since November 2000.
1796 * The command 'forward-search' can now be abbreviated as 'fo'.
1798 * The command 'info tracepoints' can now display 'installed on target'
1799 or 'not installed on target' for each non-pending location of tracepoint.
1801 * New configure options
1803 --enable-libmcheck/--disable-libmcheck
1804 By default, development versions are built with -lmcheck on hosts
1805 that support it, in order to help track memory corruption issues.
1806 Release versions, on the other hand, are built without -lmcheck
1807 by default. The --enable-libmcheck/--disable-libmcheck configure
1808 options allow the user to override that default.
1809 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1810 This configure option allows the user to build GDB with
1811 libbabeltrace using which GDB can read Common Trace Format data.
1813 * New commands (for set/show, see "New options" below)
1816 Catch signals. This is similar to "handle", but allows commands and
1817 conditions to be attached.
1820 List the BFDs known to GDB.
1822 python-interactive [command]
1824 Start a Python interactive prompt, or evaluate the optional command
1825 and print the result of expressions.
1828 "py" is a new alias for "python".
1830 enable type-printer [name]...
1831 disable type-printer [name]...
1832 Enable or disable type printers.
1836 ** For the Renesas Super-H architecture, the "regs" command has been removed
1837 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1842 set print type methods (on|off)
1843 show print type methods
1844 Control whether method declarations are displayed by "ptype".
1845 The default is to show them.
1847 set print type typedefs (on|off)
1848 show print type typedefs
1849 Control whether typedef definitions are displayed by "ptype".
1850 The default is to show them.
1852 set filename-display basename|relative|absolute
1853 show filename-display
1854 Control the way in which filenames is displayed.
1855 The default is "relative", which preserves previous behavior.
1857 set trace-buffer-size
1858 show trace-buffer-size
1859 Request target to change the size of trace buffer.
1861 set remote trace-buffer-size-packet auto|on|off
1862 show remote trace-buffer-size-packet
1863 Control the use of the remote protocol `QTBuffer:size' packet.
1867 Control display of debugging messages related to ARM AArch64.
1870 set debug coff-pe-read
1871 show debug coff-pe-read
1872 Control display of debugging messages related to reading of COFF/PE
1877 Control display of debugging messages related to Mach-O symbols
1880 set debug notification
1881 show debug notification
1882 Control display of debugging info for async remote notification.
1886 ** Command parameter changes are now notified using new async record
1887 "=cmd-param-changed".
1888 ** Trace frame changes caused by command "tfind" are now notified using
1889 new async record "=traceframe-changed".
1890 ** The creation, deletion and modification of trace state variables
1891 are now notified using new async records "=tsv-created",
1892 "=tsv-deleted" and "=tsv-modified".
1893 ** The start and stop of process record are now notified using new
1894 async record "=record-started" and "=record-stopped".
1895 ** Memory changes are now notified using new async record
1897 ** The data-disassemble command response will include a "fullname" field
1898 containing the absolute file name when source has been requested.
1899 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1900 command, to allow pattern filling of memory areas.
1901 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1902 library load/unload events.
1903 ** The response to breakpoint commands and breakpoint async records
1904 includes an "installed" field containing a boolean state about each
1905 non-pending tracepoint location is whether installed on target or not.
1906 ** Output of the "-trace-status" command includes a "trace-file" field
1907 containing the name of the trace file being examined. This field is
1908 optional, and only present when examining a trace file.
1909 ** The "fullname" field is now always present along with the "file" field,
1910 even if the file cannot be found by GDB.
1912 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1913 You must have the LZMA library available when configuring GDB for this
1914 feature to be enabled. For more information, see:
1915 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1917 * New remote packets
1920 Set the size of trace buffer. The remote stub reports support for this
1921 packet to gdb's qSupported query.
1924 Enable Branch Trace Store (BTS)-based branch tracing for the current
1925 thread. The remote stub reports support for this packet to gdb's
1929 Disable branch tracing for the current thread. The remote stub reports
1930 support for this packet to gdb's qSupported query.
1933 Read the traced branches for the current thread. The remote stub
1934 reports support for this packet to gdb's qSupported query.
1936 *** Changes in GDB 7.5
1938 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1939 for more x32 ABI info.
1941 * GDB now supports access to MIPS DSP registers on Linux targets.
1943 * GDB now supports debugging microMIPS binaries.
1945 * The "info os" command on GNU/Linux can now display information on
1946 several new classes of objects managed by the operating system:
1947 "info os procgroups" lists process groups
1948 "info os files" lists file descriptors
1949 "info os sockets" lists internet-domain sockets
1950 "info os shm" lists shared-memory regions
1951 "info os semaphores" lists semaphores
1952 "info os msg" lists message queues
1953 "info os modules" lists loaded kernel modules
1955 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1956 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1957 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1958 options and inspect the probe arguments using the new $_probe_arg family
1959 of convenience variables. You can obtain more information about SystemTap
1960 in <http://sourceware.org/systemtap/>.
1962 * GDB now supports reversible debugging on ARM, it allows you to
1963 debug basic ARM and THUMB instructions, and provides
1964 record/replay support.
1966 * The option "symbol-reloading" has been deleted as it is no longer used.
1970 ** GDB commands implemented in Python can now be put in command class
1973 ** The "maint set python print-stack on|off" is now deleted.
1975 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1976 apply "flag enum"-style pretty-printing to any enum.
1978 ** gdb.lookup_symbol can now work when there is no current frame.
1980 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1981 the source at which the symbol was defined.
1983 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1984 method 'value'. The former indicates whether the symbol needs a
1985 frame in order to compute its value, and the latter computes the
1988 ** A new method 'referenced_value' on gdb.Value objects which can
1989 dereference pointer as well as C++ reference values.
1991 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1992 which return the global and static blocks (as gdb.Block objects),
1993 of the underlying symbol table, respectively.
1995 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1996 object associated with a PC value.
1998 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1999 of the address range occupied by code for the current source line.
2001 * Go language support.
2002 GDB now supports debugging programs written in the Go programming
2005 * GDBserver now supports stdio connections.
2006 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2008 * The binary "gdbtui" can no longer be built or installed.
2009 Use "gdb -tui" instead.
2011 * GDB will now print "flag" enums specially. A flag enum is one where
2012 all the enumerator values have no bits in common when pairwise
2013 "and"ed. When printing a value whose type is a flag enum, GDB will
2014 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2015 (gdb) print (enum E) 3
2018 * The filename part of a linespec will now match trailing components
2019 of a source file name. For example, "break gcc/expr.c:1000" will
2020 now set a breakpoint in build/gcc/expr.c, but not
2021 build/libcpp/expr.c.
2023 * The "info proc" and "generate-core-file" commands will now also
2024 work on remote targets connected to GDBserver on Linux.
2026 * The command "info catch" has been removed. It has been disabled
2027 since December 2007.
2029 * The "catch exception" and "catch assert" commands now accept
2030 a condition at the end of the command, much like the "break"
2031 command does. For instance:
2033 (gdb) catch exception Constraint_Error if Barrier = True
2035 Previously, it was possible to add a condition to such catchpoints,
2036 but it had to be done as a second step, after the catchpoint had been
2037 created, using the "condition" command.
2039 * The "info static-tracepoint-marker" command will now also work on
2040 native Linux targets with in-process agent.
2042 * GDB can now set breakpoints on inlined functions.
2044 * The .gdb_index section has been updated to include symbols for
2045 inlined functions. GDB will ignore older .gdb_index sections by
2046 default, which could cause symbol files to be loaded more slowly
2047 until their .gdb_index sections can be recreated. The new command
2048 "set use-deprecated-index-sections on" will cause GDB to use any older
2049 .gdb_index sections it finds. This will restore performance, but the
2050 ability to set breakpoints on inlined functions will be lost in symbol
2051 files with older .gdb_index sections.
2053 The .gdb_index section has also been updated to record more information
2054 about each symbol. This speeds up the "info variables", "info functions"
2055 and "info types" commands when used with programs having the .gdb_index
2056 section, as well as speeding up debugging with shared libraries using
2057 the .gdb_index section.
2059 * Ada support for GDB/MI Variable Objects has been added.
2061 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2066 ** New command -info-os is the MI equivalent of "info os".
2068 ** Output logs ("set logging" and related) now include MI output.
2072 ** "set use-deprecated-index-sections on|off"
2073 "show use-deprecated-index-sections on|off"
2074 Controls the use of deprecated .gdb_index sections.
2076 ** "catch load" and "catch unload" can be used to stop when a shared
2077 library is loaded or unloaded, respectively.
2079 ** "enable count" can be used to auto-disable a breakpoint after
2082 ** "info vtbl" can be used to show the virtual method tables for
2083 C++ and Java objects.
2085 ** "explore" and its sub commands "explore value" and "explore type"
2086 can be used to recursively explore values and types of
2087 expressions. These commands are available only if GDB is
2088 configured with '--with-python'.
2090 ** "info auto-load" shows status of all kinds of auto-loaded files,
2091 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2092 sequences of commands files, "info auto-load python-scripts"
2093 shows status of auto-loading Python script files,
2094 "info auto-load local-gdbinit" shows status of loading init file
2095 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2096 status of inferior specific thread debugging shared library loading.
2098 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2099 and "show auto-load-scripts" commands have been deprecated, use their
2100 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2101 and "show auto-load python-scripts" counterparts instead.
2103 ** "dprintf location,format,args..." creates a dynamic printf, which
2104 is basically a breakpoint that does a printf and immediately
2105 resumes your program's execution, so it is like a printf that you
2106 can insert dynamically at runtime instead of at compiletime.
2108 ** "set print symbol"
2110 Controls whether GDB attempts to display the symbol, if any,
2111 corresponding to addresses it prints. This defaults to "on", but
2112 you can set it to "off" to restore GDB's previous behavior.
2114 * Deprecated commands
2116 ** For the Renesas Super-H architecture, the "regs" command has been
2117 deprecated, and "info all-registers" should be used instead.
2121 Renesas RL78 rl78-*-elf
2122 HP OpenVMS ia64 ia64-hp-openvms*
2124 * GDBserver supports evaluation of breakpoint conditions. When
2125 support is advertised by GDBserver, GDB may be told to send the
2126 breakpoint conditions in bytecode form to GDBserver. GDBserver
2127 will only report the breakpoint trigger to GDB when its condition
2132 set mips compression
2133 show mips compression
2134 Select the compressed ISA encoding used in functions that have no symbol
2135 information available. The encoding can be set to either of:
2138 and is updated automatically from ELF file flags if available.
2140 set breakpoint condition-evaluation
2141 show breakpoint condition-evaluation
2142 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2143 GDBserver ("target"). Default option "auto" chooses the most efficient
2145 This option can improve debugger efficiency depending on the speed of the
2149 Disable auto-loading globally.
2152 Show auto-loading setting of all kinds of auto-loaded files.
2154 set auto-load gdb-scripts on|off
2155 show auto-load gdb-scripts
2156 Control auto-loading of GDB canned sequences of commands files.
2158 set auto-load python-scripts on|off
2159 show auto-load python-scripts
2160 Control auto-loading of Python script files.
2162 set auto-load local-gdbinit on|off
2163 show auto-load local-gdbinit
2164 Control loading of init file (.gdbinit) from current directory.
2166 set auto-load libthread-db on|off
2167 show auto-load libthread-db
2168 Control auto-loading of inferior specific thread debugging shared library.
2170 set auto-load scripts-directory <dir1>[:<dir2>...]
2171 show auto-load scripts-directory
2172 Set a list of directories from which to load auto-loaded scripts.
2173 Automatically loaded Python scripts and GDB scripts are located in one
2174 of the directories listed by this option.
2175 The delimiter (':' above) may differ according to the host platform.
2177 set auto-load safe-path <dir1>[:<dir2>...]
2178 show auto-load safe-path
2179 Set a list of directories from which it is safe to auto-load files.
2180 The delimiter (':' above) may differ according to the host platform.
2182 set debug auto-load on|off
2183 show debug auto-load
2184 Control display of debugging info for auto-loading the files above.
2186 set dprintf-style gdb|call|agent
2188 Control the way in which a dynamic printf is performed; "gdb"
2189 requests a GDB printf command, while "call" causes dprintf to call a
2190 function in the inferior. "agent" requests that the target agent
2191 (such as GDBserver) do the printing.
2193 set dprintf-function <expr>
2194 show dprintf-function
2195 set dprintf-channel <expr>
2196 show dprintf-channel
2197 Set the function and optional first argument to the call when using
2198 the "call" style of dynamic printf.
2200 set disconnected-dprintf on|off
2201 show disconnected-dprintf
2202 Control whether agent-style dynamic printfs continue to be in effect
2203 after GDB disconnects.
2205 * New configure options
2207 --with-auto-load-dir
2208 Configure default value for the 'set auto-load scripts-directory'
2209 setting above. It defaults to '$debugdir:$datadir/auto-load',
2210 $debugdir representing global debugging info directories (available
2211 via 'show debug-file-directory') and $datadir representing GDB's data
2212 directory (available via 'show data-directory').
2214 --with-auto-load-safe-path
2215 Configure default value for the 'set auto-load safe-path' setting
2216 above. It defaults to the --with-auto-load-dir setting.
2218 --without-auto-load-safe-path
2219 Set 'set auto-load safe-path' to '/', effectively disabling this
2222 * New remote packets
2224 z0/z1 conditional breakpoints extension
2226 The z0/z1 breakpoint insertion packets have been extended to carry
2227 a list of conditional expressions over to the remote stub depending on the
2228 condition evaluation mode. The use of this extension can be controlled
2229 via the "set remote conditional-breakpoints-packet" command.
2233 Specify the signals which the remote stub may pass to the debugged
2234 program without GDB involvement.
2236 * New command line options
2238 --init-command=FILE, -ix Like --command, -x but execute it
2239 before loading inferior.
2240 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2241 execute it before loading inferior.
2243 *** Changes in GDB 7.4
2245 * GDB now handles ambiguous linespecs more consistently; the existing
2246 FILE:LINE support has been expanded to other types of linespecs. A
2247 breakpoint will now be set on all matching locations in all
2248 inferiors, and locations will be added or removed according to
2251 * GDB now allows you to skip uninteresting functions and files when
2252 stepping with the "skip function" and "skip file" commands.
2254 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2255 and "show remote hardware-watchpoint-length-limit". These allows to
2256 set or show the maximum length limit (in bytes) of a remote
2257 target hardware watchpoint.
2259 This allows e.g. to use "unlimited" hardware watchpoints with the
2260 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2261 watchpoints are slower than real hardware watchpoints but are
2262 significantly faster than gdb software watchpoints.
2266 ** The register_pretty_printer function in module gdb.printing now takes
2267 an optional `replace' argument. If True, the new printer replaces any
2270 ** The "maint set python print-stack on|off" command has been
2271 deprecated and will be deleted in GDB 7.5.
2272 A new command: "set python print-stack none|full|message" has
2273 replaced it. Additionally, the default for "print-stack" is
2274 now "message", which just prints the error message without
2277 ** A prompt substitution hook (prompt_hook) is now available to the
2280 ** A new Python module, gdb.prompt has been added to the GDB Python
2281 modules library. This module provides functionality for
2282 escape sequences in prompts (used by set/show
2283 extended-prompt). These escape sequences are replaced by their
2284 corresponding value.
2286 ** Python commands and convenience-functions located in
2287 'data-directory'/python/gdb/command and
2288 'data-directory'/python/gdb/function are now automatically loaded
2291 ** Blocks now provide four new attributes. global_block and
2292 static_block will return the global and static blocks
2293 respectively. is_static and is_global are boolean attributes
2294 that indicate if the block is one of those two types.
2296 ** Symbols now provide the "type" attribute, the type of the symbol.
2298 ** The "gdb.breakpoint" function has been deprecated in favor of
2301 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2302 of a function. This class is based on the "finish" command
2303 available in the CLI.
2305 ** Type objects for struct and union types now allow access to
2306 the fields using standard Python dictionary (mapping) methods.
2307 For example, "some_type['myfield']" now works, as does
2308 "some_type.items()".
2310 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2313 ** A new function, "deep_items" has been added to the gdb.types
2314 module in the GDB Python modules library. This function returns
2315 an iterator over the fields of a struct or union type. Unlike
2316 the standard Python "iteritems" method, it will recursively traverse
2317 any anonymous fields.
2321 ** "*stopped" events can report several new "reason"s, such as
2324 ** Breakpoint changes are now notified using new async records, like
2325 "=breakpoint-modified".
2327 ** New command -ada-task-info.
2329 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2330 $sdir specifies the default system locations of shared libraries.
2331 $pdir specifies the directory where the libpthread used by the application
2334 GDB no longer looks in $sdir and $pdir after it has searched the directories
2335 mentioned in libthread-db-search-path. If you want to search those
2336 directories, they must be specified in libthread-db-search-path.
2337 The default value of libthread-db-search-path on GNU/Linux and Solaris
2338 systems is now "$sdir:$pdir".
2340 $pdir is not supported by gdbserver, it is currently ignored.
2341 $sdir is supported by gdbserver.
2343 * New configure option --with-iconv-bin.
2344 When using the internationalization support like the one in the GNU C
2345 library, GDB will invoke the "iconv" program to get a list of supported
2346 character sets. If this program lives in a non-standard location, one can
2347 use this option to specify where to find it.
2349 * When natively debugging programs on PowerPC BookE processors running
2350 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2351 watchpoints, which specify a mask in addition to an address to watch.
2352 The mask specifies that some bits of an address (the bits which are
2353 reset in the mask) should be ignored when matching the address accessed
2354 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2355 section in the user manual for more details.
2357 * The new option --once causes GDBserver to stop listening for connections once
2358 the first connection is made. The listening port used by GDBserver will
2359 become available after that.
2361 * New commands "info macros" and "alias" have been added.
2363 * New function parameters suffix @entry specifies value of function parameter
2364 at the time the function got called. Entry values are available only since
2370 "!" is now an alias of the "shell" command.
2371 Note that no space is needed between "!" and SHELL COMMAND.
2375 watch EXPRESSION mask MASK_VALUE
2376 The watch command now supports the mask argument which allows creation
2377 of masked watchpoints, if the current architecture supports this feature.
2379 info auto-load-scripts [REGEXP]
2380 This command was formerly named "maintenance print section-scripts".
2381 It is now generally useful and is no longer a maintenance-only command.
2383 info macro [-all] [--] MACRO
2384 The info macro command has new options `-all' and `--'. The first for
2385 printing all definitions of a macro. The second for explicitly specifying
2386 the end of arguments and the beginning of the macro name in case the macro
2387 name starts with a hyphen.
2389 collect[/s] EXPRESSIONS
2390 The tracepoint collect command now takes an optional modifier "/s"
2391 that directs it to dereference pointer-to-character types and
2392 collect the bytes of memory up to a zero byte. The behavior is
2393 similar to what you see when you use the regular print command on a
2394 string. An optional integer following the "/s" sets a bound on the
2395 number of bytes that will be collected.
2398 The trace start command now interprets any supplied arguments as a
2399 note to be recorded with the trace run, with an effect similar to
2400 setting the variable trace-notes.
2403 The trace stop command now interprets any arguments as a note to be
2404 mentioned along with the tstatus report that the trace was stopped
2405 with a command. The effect is similar to setting the variable
2408 * Tracepoints can now be enabled and disabled at any time after a trace
2409 experiment has been started using the standard "enable" and "disable"
2410 commands. It is now possible to start a trace experiment with no enabled
2411 tracepoints; GDB will display a warning, but will allow the experiment to
2412 begin, assuming that tracepoints will be enabled as needed while the trace
2415 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2416 locations with 4-byte instructions, when they were previously
2417 limited to locations with instructions of 5 bytes or longer.
2421 set debug dwarf2-read
2422 show debug dwarf2-read
2423 Turns on or off display of debugging messages related to reading
2424 DWARF debug info. The default is off.
2426 set debug symtab-create
2427 show debug symtab-create
2428 Turns on or off display of debugging messages related to symbol table
2429 creation. The default is off.
2432 show extended-prompt
2433 Set the GDB prompt, and allow escape sequences to be inserted to
2434 display miscellaneous information (see 'help set extended-prompt'
2435 for the list of sequences). This prompt (and any information
2436 accessed through the escape sequences) is updated every time the
2437 prompt is displayed.
2439 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2440 show print entry-values
2441 Set printing of frame argument values at function entry. In some cases
2442 GDB can determine the value of function argument which was passed by the
2443 function caller, even if the value was modified inside the called function.
2445 set debug entry-values
2446 show debug entry-values
2447 Control display of debugging info for determining frame argument values at
2448 function entry and virtual tail call frames.
2450 set basenames-may-differ
2451 show basenames-may-differ
2452 Set whether a source file may have multiple base names.
2453 (A "base name" is the name of a file with the directory part removed.
2454 Example: The base name of "/home/user/hello.c" is "hello.c".)
2455 If set, GDB will canonicalize file names (e.g., expand symlinks)
2456 before comparing them. Canonicalization is an expensive operation,
2457 but it allows the same file be known by more than one base name.
2458 If not set (the default), all source files are assumed to have just
2459 one base name, and gdb will do file name comparisons more efficiently.
2465 Set a user name and notes for the current and any future trace runs.
2466 This is useful for long-running and/or disconnected traces, to
2467 inform others (or yourself) as to who is running the trace, supply
2468 contact information, or otherwise explain what is going on.
2470 set trace-stop-notes
2471 show trace-stop-notes
2472 Set a note attached to the trace run, that is displayed when the
2473 trace has been stopped by a tstop command. This is useful for
2474 instance as an explanation, if you are stopping a trace run that was
2475 started by someone else.
2477 * New remote packets
2481 Dynamically enable a tracepoint in a started trace experiment.
2485 Dynamically disable a tracepoint in a started trace experiment.
2489 Set the user and notes of the trace run.
2493 Query the current status of a tracepoint.
2497 Query the minimum length of instruction at which a fast tracepoint may
2500 * Dcache size (number of lines) and line-size are now runtime-configurable
2501 via "set dcache line" and "set dcache line-size" commands.
2505 Texas Instruments TMS320C6x tic6x-*-*
2509 Renesas RL78 rl78-*-elf
2511 *** Changes in GDB 7.3.1
2513 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2515 *** Changes in GDB 7.3
2517 * GDB has a new command: "thread find [REGEXP]".
2518 It finds the thread id whose name, target id, or thread extra info
2519 matches the given regular expression.
2521 * The "catch syscall" command now works on mips*-linux* targets.
2523 * The -data-disassemble MI command now supports modes 2 and 3 for
2524 dumping the instruction opcodes.
2526 * New command line options
2528 -data-directory DIR Specify DIR as the "data-directory".
2529 This is mostly for testing purposes.
2531 * The "maint set python auto-load on|off" command has been renamed to
2532 "set auto-load-scripts on|off".
2534 * GDB has a new command: "set directories".
2535 It is like the "dir" command except that it replaces the
2536 source path list instead of augmenting it.
2538 * GDB now understands thread names.
2540 On GNU/Linux, "info threads" will display the thread name as set by
2541 prctl or pthread_setname_np.
2543 There is also a new command, "thread name", which can be used to
2544 assign a name internally for GDB to display.
2547 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2548 has been integrated into GDB.
2552 ** The function gdb.Write now accepts an optional keyword 'stream'.
2553 This keyword, when provided, will direct the output to either
2554 stdout, stderr, or GDB's logging output.
2556 ** Parameters can now be be sub-classed in Python, and in particular
2557 you may implement the get_set_doc and get_show_doc functions.
2558 This improves how Parameter set/show documentation is processed
2559 and allows for more dynamic content.
2561 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2562 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2563 have an is_valid method.
2565 ** Breakpoints can now be sub-classed in Python, and in particular
2566 you may implement a 'stop' function that is executed each time
2567 the inferior reaches that breakpoint.
2569 ** New function gdb.lookup_global_symbol looks up a global symbol.
2571 ** GDB values in Python are now callable if the value represents a
2572 function. For example, if 'some_value' represents a function that
2573 takes two integer parameters and returns a value, you can call
2574 that function like so:
2576 result = some_value (10,20)
2578 ** Module gdb.types has been added.
2579 It contains a collection of utilities for working with gdb.Types objects:
2580 get_basic_type, has_field, make_enum_dict.
2582 ** Module gdb.printing has been added.
2583 It contains utilities for writing and registering pretty-printers.
2584 New classes: PrettyPrinter, SubPrettyPrinter,
2585 RegexpCollectionPrettyPrinter.
2586 New function: register_pretty_printer.
2588 ** New commands "info pretty-printers", "enable pretty-printer" and
2589 "disable pretty-printer" have been added.
2591 ** gdb.parameter("directories") is now available.
2593 ** New function gdb.newest_frame returns the newest frame in the
2596 ** The gdb.InferiorThread class has a new "name" attribute. This
2597 holds the thread's name.
2599 ** Python Support for Inferior events.
2600 Python scripts can add observers to be notified of events
2601 occurring in the process being debugged.
2602 The following events are currently supported:
2603 - gdb.events.cont Continue event.
2604 - gdb.events.exited Inferior exited event.
2605 - gdb.events.stop Signal received, and Breakpoint hit events.
2609 ** GDB now puts template parameters in scope when debugging in an
2610 instantiation. For example, if you have:
2612 template<int X> int func (void) { return X; }
2614 then if you step into func<5>, "print X" will show "5". This
2615 feature requires proper debuginfo support from the compiler; it
2616 was added to GCC 4.5.
2618 ** The motion commands "next", "finish", "until", and "advance" now
2619 work better when exceptions are thrown. In particular, GDB will
2620 no longer lose control of the inferior; instead, the GDB will
2621 stop the inferior at the point at which the exception is caught.
2622 This functionality requires a change in the exception handling
2623 code that was introduced in GCC 4.5.
2625 * GDB now follows GCC's rules on accessing volatile objects when
2626 reading or writing target state during expression evaluation.
2627 One notable difference to prior behavior is that "print x = 0"
2628 no longer generates a read of x; the value of the assignment is
2629 now always taken directly from the value being assigned.
2631 * GDB now has some support for using labels in the program's source in
2632 linespecs. For instance, you can use "advance label" to continue
2633 execution to a label.
2635 * GDB now has support for reading and writing a new .gdb_index
2636 section. This section holds a fast index of DWARF debugging
2637 information and can be used to greatly speed up GDB startup and
2638 operation. See the documentation for `save gdb-index' for details.
2640 * The "watch" command now accepts an optional "-location" argument.
2641 When used, this causes GDB to watch the memory referred to by the
2642 expression. Such a watchpoint is never deleted due to it going out
2645 * GDB now supports thread debugging of core dumps on GNU/Linux.
2647 GDB now activates thread debugging using the libthread_db library
2648 when debugging GNU/Linux core dumps, similarly to when debugging
2649 live processes. As a result, when debugging a core dump file, GDB
2650 is now able to display pthread_t ids of threads. For example, "info
2651 threads" shows the same output as when debugging the process when it
2652 was live. In earlier releases, you'd see something like this:
2655 * 1 LWP 6780 main () at main.c:10
2657 While now you see this:
2660 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2662 It is also now possible to inspect TLS variables when debugging core
2665 When debugging a core dump generated on a machine other than the one
2666 used to run GDB, you may need to point GDB at the correct
2667 libthread_db library with the "set libthread-db-search-path"
2668 command. See the user manual for more details on this command.
2670 * When natively debugging programs on PowerPC BookE processors running
2671 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2672 which stop execution of the inferior whenever it executes an instruction
2673 at any address within the specified range. See the "PowerPC Embedded"
2674 section in the user manual for more details.
2676 * New features in the GDB remote stub, GDBserver
2678 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2679 and i686 LynxOS (version 5.x).
2681 ** GDBserver is now supported on Blackfin Linux.
2683 * New native configurations
2685 ia64 HP-UX ia64-*-hpux*
2689 Analog Devices, Inc. Blackfin Processor bfin-*
2691 * Ada task switching is now supported on sparc-elf targets when
2692 debugging a program using the Ravenscar Profile. For more information,
2693 see the "Tasking Support when using the Ravenscar Profile" section
2694 in the GDB user manual.
2696 * Guile support was removed.
2698 * New features in the GNU simulator
2700 ** The --map-info flag lists all known core mappings.
2702 ** CFI flashes may be simulated via the "cfi" device.
2704 *** Changes in GDB 7.2
2706 * Shared library support for remote targets by default
2708 When GDB is configured for a generic, non-OS specific target, like
2709 for example, --target=arm-eabi or one of the many *-*-elf targets,
2710 GDB now queries remote stubs for loaded shared libraries using the
2711 `qXfer:libraries:read' packet. Previously, shared library support
2712 was always disabled for such configurations.
2716 ** Argument Dependent Lookup (ADL)
2718 In C++ ADL lookup directs function search to the namespaces of its
2719 arguments even if the namespace has not been imported.
2729 Here the compiler will search for `foo' in the namespace of 'b'
2730 and find A::foo. GDB now supports this. This construct is commonly
2731 used in the Standard Template Library for operators.
2733 ** Improved User Defined Operator Support
2735 In addition to member operators, GDB now supports lookup of operators
2736 defined in a namespace and imported with a `using' directive, operators
2737 defined in the global scope, operators imported implicitly from an
2738 anonymous namespace, and the ADL operators mentioned in the previous
2740 GDB now also supports proper overload resolution for all the previously
2741 mentioned flavors of operators.
2743 ** static const class members
2745 Printing of static const class members that are initialized in the
2746 class definition has been fixed.
2748 * Windows Thread Information Block access.
2750 On Windows targets, GDB now supports displaying the Windows Thread
2751 Information Block (TIB) structure. This structure is visible either
2752 by using the new command `info w32 thread-information-block' or, by
2753 dereferencing the new convenience variable named `$_tlb', a
2754 thread-specific pointer to the TIB. This feature is also supported
2755 when remote debugging using GDBserver.
2757 * Static tracepoints
2759 Static tracepoints are calls in the user program into a tracing
2760 library. One such library is a port of the LTTng kernel tracer to
2761 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2762 When debugging with GDBserver, GDB now supports combining the GDB
2763 tracepoint machinery with such libraries. For example: the user can
2764 use GDB to probe a static tracepoint marker (a call from the user
2765 program into the tracing library) with the new "strace" command (see
2766 "New commands" below). This creates a "static tracepoint" in the
2767 breakpoint list, that can be manipulated with the same feature set
2768 as fast and regular tracepoints. E.g., collect registers, local and
2769 global variables, collect trace state variables, and define
2770 tracepoint conditions. In addition, the user can collect extra
2771 static tracepoint marker specific data, by collecting the new
2772 $_sdata internal variable. When analyzing the trace buffer, you can
2773 inspect $_sdata like any other variable available to GDB. For more
2774 information, see the "Tracepoints" chapter in GDB user manual. New
2775 remote packets have been defined to support static tracepoints, see
2776 the "New remote packets" section below.
2778 * Better reconstruction of tracepoints after disconnected tracing
2780 GDB will attempt to download the original source form of tracepoint
2781 definitions when starting a trace run, and then will upload these
2782 upon reconnection to the target, resulting in a more accurate
2783 reconstruction of the tracepoints that are in use on the target.
2787 You can now exercise direct control over the ways that GDB can
2788 affect your program. For instance, you can disallow the setting of
2789 breakpoints, so that the program can run continuously (assuming
2790 non-stop mode). In addition, the "observer" variable is available
2791 to switch all of the different controls; in observer mode, GDB
2792 cannot affect the target's behavior at all, which is useful for
2793 tasks like diagnosing live systems in the field.
2795 * The new convenience variable $_thread holds the number of the
2798 * New remote packets
2802 Return the address of the Windows Thread Information Block of a given thread.
2806 In response to several of the tracepoint packets, the target may now
2807 also respond with a number of intermediate `qRelocInsn' request
2808 packets before the final result packet, to have GDB handle
2809 relocating an instruction to execute at a different address. This
2810 is particularly useful for stubs that support fast tracepoints. GDB
2811 reports support for this feature in the qSupported packet.
2815 List static tracepoint markers in the target program.
2819 List static tracepoint markers at a given address in the target
2822 qXfer:statictrace:read
2824 Read the static trace data collected (by a `collect $_sdata'
2825 tracepoint action). The remote stub reports support for this packet
2826 to gdb's qSupported query.
2830 Send the current settings of GDB's permission flags.
2834 Send part of the source (textual) form of a tracepoint definition,
2835 which includes location, conditional, and action list.
2837 * The source command now accepts a -s option to force searching for the
2838 script in the source search path even if the script name specifies
2841 * New features in the GDB remote stub, GDBserver
2843 - GDBserver now support tracepoints (including fast tracepoints, and
2844 static tracepoints). The feature is currently supported by the
2845 i386-linux and amd64-linux builds. See the "Tracepoints support
2846 in gdbserver" section in the manual for more information.
2848 GDBserver JIT compiles the tracepoint's conditional agent
2849 expression bytecode into native code whenever possible for low
2850 overhead dynamic tracepoints conditionals. For such tracepoints,
2851 an expression that examines program state is evaluated when the
2852 tracepoint is reached, in order to determine whether to capture
2853 trace data. If the condition is simple and false, processing the
2854 tracepoint finishes very quickly and no data is gathered.
2856 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2857 for static tracepoints support.
2859 - GDBserver now supports x86_64 Windows 64-bit debugging.
2861 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2862 it understands register description.
2864 * The --batch flag now disables pagination and queries.
2866 * X86 general purpose registers
2868 GDB now supports reading/writing byte, word and double-word x86
2869 general purpose registers directly. This means you can use, say,
2870 $ah or $ax to refer, respectively, to the byte register AH and
2871 16-bit word register AX that are actually portions of the 32-bit
2872 register EAX or 64-bit register RAX.
2874 * The `commands' command now accepts a range of breakpoints to modify.
2875 A plain `commands' following a command that creates multiple
2876 breakpoints affects all the breakpoints set by that command. This
2877 applies to breakpoints set by `rbreak', and also applies when a
2878 single `break' command creates multiple breakpoints (e.g.,
2879 breakpoints on overloaded c++ functions).
2881 * The `rbreak' command now accepts a filename specification as part of
2882 its argument, limiting the functions selected by the regex to those
2883 in the specified file.
2885 * Support for remote debugging Windows and SymbianOS shared libraries
2886 from Unix hosts has been improved. Non Windows GDB builds now can
2887 understand target reported file names that follow MS-DOS based file
2888 system semantics, such as file names that include drive letters and
2889 use the backslash character as directory separator. This makes it
2890 possible to transparently use the "set sysroot" and "set
2891 solib-search-path" on Unix hosts to point as host copies of the
2892 target's shared libraries. See the new command "set
2893 target-file-system-kind" described below, and the "Commands to
2894 specify files" section in the user manual for more information.
2898 eval template, expressions...
2899 Convert the values of one or more expressions under the control
2900 of the string template to a command line, and call it.
2902 set target-file-system-kind unix|dos-based|auto
2903 show target-file-system-kind
2904 Set or show the assumed file system kind for target reported file
2907 save breakpoints <filename>
2908 Save all current breakpoint definitions to a file suitable for use
2909 in a later debugging session. To read the saved breakpoint
2910 definitions, use the `source' command.
2912 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2915 info static-tracepoint-markers
2916 Display information about static tracepoint markers in the target.
2918 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2919 Define a static tracepoint by probing a marker at the given
2920 function, line, address, or marker ID.
2924 Enable and disable observer mode.
2926 set may-write-registers on|off
2927 set may-write-memory on|off
2928 set may-insert-breakpoints on|off
2929 set may-insert-tracepoints on|off
2930 set may-insert-fast-tracepoints on|off
2931 set may-interrupt on|off
2932 Set individual permissions for GDB effects on the target. Note that
2933 some of these settings can have undesirable or surprising
2934 consequences, particularly when changed in the middle of a session.
2935 For instance, disabling the writing of memory can prevent
2936 breakpoints from being inserted, cause single-stepping to fail, or
2937 even crash your program, if you disable after breakpoints have been
2938 inserted. However, GDB should not crash.
2940 set record memory-query on|off
2941 show record memory-query
2942 Control whether to stop the inferior if memory changes caused
2943 by an instruction cannot be recorded.
2948 The disassemble command now supports "start,+length" form of two arguments.
2952 ** GDB now provides a new directory location, called the python directory,
2953 where Python scripts written for GDB can be installed. The location
2954 of that directory is <data-directory>/python, where <data-directory>
2955 is the GDB data directory. For more details, see section `Scripting
2956 GDB using Python' in the manual.
2958 ** The GDB Python API now has access to breakpoints, symbols, symbol
2959 tables, program spaces, inferiors, threads and frame's code blocks.
2960 Additionally, GDB Parameters can now be created from the API, and
2961 manipulated via set/show in the CLI.
2963 ** New functions gdb.target_charset, gdb.target_wide_charset,
2964 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2966 ** New exception gdb.GdbError.
2968 ** Pretty-printers are now also looked up in the current program space.
2970 ** Pretty-printers can now be individually enabled and disabled.
2972 ** GDB now looks for names of Python scripts to auto-load in a
2973 special section named `.debug_gdb_scripts', in addition to looking
2974 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2976 * Tracepoint actions were unified with breakpoint commands. In particular,
2977 there are no longer differences in "info break" output for breakpoints and
2978 tracepoints and the "commands" command can be used for both tracepoints and
2979 regular breakpoints.
2983 ARM Symbian arm*-*-symbianelf*
2985 * D language support.
2986 GDB now supports debugging programs written in the D programming
2989 * GDB now supports the extended ptrace interface for PowerPC which is
2990 available since Linux kernel version 2.6.34. This automatically enables
2991 any hardware breakpoints and additional hardware watchpoints available in
2992 the processor. The old ptrace interface exposes just one hardware
2993 watchpoint and no hardware breakpoints.
2995 * GDB is now able to use the Data Value Compare (DVC) register available on
2996 embedded PowerPC processors to implement in hardware simple watchpoint
2997 conditions of the form:
2999 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3001 This works in native GDB running on Linux kernels with the extended ptrace
3002 interface mentioned above.
3004 *** Changes in GDB 7.1
3008 ** Namespace Support
3010 GDB now supports importing of namespaces in C++. This enables the
3011 user to inspect variables from imported namespaces. Support for
3012 namepace aliasing has also been added. So, if a namespace is
3013 aliased in the current scope (e.g. namepace C=A; ) the user can
3014 print variables using the alias (e.g. (gdb) print C::x).
3018 All known bugs relating to the printing of virtual base class were
3019 fixed. It is now possible to call overloaded static methods using a
3024 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3025 and reinterpret_cast<> are now handled by the C++ expression parser.
3029 Xilinx MicroBlaze microblaze-*-*
3034 Xilinx MicroBlaze microblaze
3037 * Multi-program debugging.
3039 GDB now has support for multi-program (a.k.a. multi-executable or
3040 multi-exec) debugging. This allows for debugging multiple inferiors
3041 simultaneously each running a different program under the same GDB
3042 session. See "Debugging Multiple Inferiors and Programs" in the
3043 manual for more information. This implied some user visible changes
3044 in the multi-inferior support. For example, "info inferiors" now
3045 lists inferiors that are not running yet or that have exited
3046 already. See also "New commands" and "New options" below.
3048 * New tracing features
3050 GDB's tracepoint facility now includes several new features:
3052 ** Trace state variables
3054 GDB tracepoints now include support for trace state variables, which
3055 are variables managed by the target agent during a tracing
3056 experiment. They are useful for tracepoints that trigger each
3057 other, so for instance one tracepoint can count hits in a variable,
3058 and then a second tracepoint has a condition that is true when the
3059 count reaches a particular value. Trace state variables share the
3060 $-syntax of GDB convenience variables, and can appear in both
3061 tracepoint actions and condition expressions. Use the "tvariable"
3062 command to create, and "info tvariables" to view; see "Trace State
3063 Variables" in the manual for more detail.
3067 GDB now includes an option for defining fast tracepoints, which
3068 targets may implement more efficiently, such as by installing a jump
3069 into the target agent rather than a trap instruction. The resulting
3070 speedup can be by two orders of magnitude or more, although the
3071 tradeoff is that some program locations on some target architectures
3072 might not allow fast tracepoint installation, for instance if the
3073 instruction to be replaced is shorter than the jump. To request a
3074 fast tracepoint, use the "ftrace" command, with syntax identical to
3075 the regular trace command.
3077 ** Disconnected tracing
3079 It is now possible to detach GDB from the target while it is running
3080 a trace experiment, then reconnect later to see how the experiment
3081 is going. In addition, a new variable disconnected-tracing lets you
3082 tell the target agent whether to continue running a trace if the
3083 connection is lost unexpectedly.
3087 GDB now has the ability to save the trace buffer into a file, and
3088 then use that file as a target, similarly to you can do with
3089 corefiles. You can select trace frames, print data that was
3090 collected in them, and use tstatus to display the state of the
3091 tracing run at the moment that it was saved. To create a trace
3092 file, use "tsave <filename>", and to use it, do "target tfile
3095 ** Circular trace buffer
3097 You can ask the target agent to handle the trace buffer as a
3098 circular buffer, discarding the oldest trace frames to make room for
3099 newer ones, by setting circular-trace-buffer to on. This feature may
3100 not be available for all target agents.
3105 The disassemble command, when invoked with two arguments, now requires
3106 the arguments to be comma-separated.
3109 The info variables command now displays variable definitions. Files
3110 which only declare a variable are not shown.
3113 The source command is now capable of sourcing Python scripts.
3114 This feature is dependent on the debugger being build with Python
3117 Related to this enhancement is also the introduction of a new command
3118 "set script-extension" (see below).
3120 * New commands (for set/show, see "New options" below)
3122 record save [<FILENAME>]
3123 Save a file (in core file format) containing the process record
3124 execution log for replay debugging at a later time.
3126 record restore <FILENAME>
3127 Restore the process record execution log that was saved at an
3128 earlier time, for replay debugging.
3130 add-inferior [-copies <N>] [-exec <FILENAME>]
3133 clone-inferior [-copies <N>] [ID]
3134 Make a new inferior ready to execute the same program another
3135 inferior has loaded.
3140 maint info program-spaces
3141 List the program spaces loaded into GDB.
3143 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3144 show remote interrupt-sequence
3145 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3146 as the sequence to the remote target in order to interrupt the execution.
3147 Ctrl-C is a default. Some system prefers BREAK which is high level of
3148 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3149 Magic SysRq g. It is BREAK signal and character 'g'.
3151 set remote interrupt-on-connect [on | off]
3152 show remote interrupt-on-connect
3153 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3154 remote target when gdb connects to it. This is needed when you debug
3157 set remotebreak [on | off]
3159 Deprecated. Use "set/show remote interrupt-sequence" instead.
3161 tvariable $NAME [ = EXP ]
3162 Create or modify a trace state variable.
3165 List trace state variables and their values.
3167 delete tvariable $NAME ...
3168 Delete one or more trace state variables.
3171 Evaluate the given expressions without collecting anything into the
3172 trace buffer. (Valid in tracepoint actions only.)
3174 ftrace FN / FILE:LINE / *ADDR
3175 Define a fast tracepoint at the given function, line, or address.
3177 * New expression syntax
3179 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3180 GDB now parses 0b101010 identically with 42.
3184 set follow-exec-mode new|same
3185 show follow-exec-mode
3186 Control whether GDB reuses the same inferior across an exec call or
3187 creates a new one. This is useful to be able to restart the old
3188 executable after the inferior having done an exec call.
3190 set default-collect EXPR, ...
3191 show default-collect
3192 Define a list of expressions to be collected at each tracepoint.
3193 This is a useful way to ensure essential items are not overlooked,
3194 such as registers or a critical global variable.
3196 set disconnected-tracing
3197 show disconnected-tracing
3198 If set to 1, the target is instructed to continue tracing if it
3199 loses its connection to GDB. If 0, the target is to stop tracing
3202 set circular-trace-buffer
3203 show circular-trace-buffer
3204 If set to on, the target is instructed to use a circular trace buffer
3205 and discard the oldest trace frames instead of stopping the trace due
3206 to a full trace buffer. If set to off, the trace stops when the buffer
3207 fills up. Some targets may not support this.
3209 set script-extension off|soft|strict
3210 show script-extension
3211 If set to "off", the debugger does not perform any script language
3212 recognition, and all sourced files are assumed to be GDB scripts.
3213 If set to "soft" (the default), files are sourced according to
3214 filename extension, falling back to GDB scripts if the first
3216 If set to "strict", files are sourced according to filename extension.
3218 set ada trust-PAD-over-XVS on|off
3219 show ada trust-PAD-over-XVS
3220 If off, activate a workaround against a bug in the debugging information
3221 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3222 the GCC sources for more information about the GNAT encoding and
3223 PAD types in particular). It is always safe to set this option to
3224 off, but this introduces a slight performance penalty. The default
3227 * Python API Improvements
3229 ** GDB provides the new class gdb.LazyString. This is useful in
3230 some pretty-printing cases. The new method gdb.Value.lazy_string
3231 provides a simple way to create objects of this type.
3233 ** The fields returned by gdb.Type.fields now have an
3234 `is_base_class' attribute.
3236 ** The new method gdb.Type.range returns the range of an array type.
3238 ** The new method gdb.parse_and_eval can be used to parse and
3239 evaluate an expression.
3241 * New remote packets
3244 Define a trace state variable.
3247 Get the current value of a trace state variable.
3250 Set desired tracing behavior upon disconnection.
3253 Set the trace buffer to be linear or circular.
3256 Get data about the tracepoints currently in use.
3260 Process record now works correctly with hardware watchpoints.
3262 Multiple bug fixes have been made to the mips-irix port, making it
3263 much more reliable. In particular:
3264 - Debugging threaded applications is now possible again. Previously,
3265 GDB would hang while starting the program, or while waiting for
3266 the program to stop at a breakpoint.
3267 - Attaching to a running process no longer hangs.
3268 - An error occurring while loading a core file has been fixed.
3269 - Changing the value of the PC register now works again. This fixes
3270 problems observed when using the "jump" command, or when calling
3271 a function from GDB, or even when assigning a new value to $pc.
3272 - With the "finish" and "return" commands, the return value for functions
3273 returning a small array is now correctly printed.
3274 - It is now possible to break on shared library code which gets executed
3275 during a shared library init phase (code executed while executing
3276 their .init section). Previously, the breakpoint would have no effect.
3277 - GDB is now able to backtrace through the signal handler for
3278 non-threaded programs.
3280 PIE (Position Independent Executable) programs debugging is now supported.
3281 This includes debugging execution of PIC (Position Independent Code) shared
3282 libraries although for that, it should be possible to run such libraries as an
3285 *** Changes in GDB 7.0
3287 * GDB now has an interface for JIT compilation. Applications that
3288 dynamically generate code can create symbol files in memory and register
3289 them with GDB. For users, the feature should work transparently, and
3290 for JIT developers, the interface is documented in the GDB manual in the
3291 "JIT Compilation Interface" chapter.
3293 * Tracepoints may now be conditional. The syntax is as for
3294 breakpoints; either an "if" clause appended to the "trace" command,
3295 or the "condition" command is available. GDB sends the condition to
3296 the target for evaluation using the same bytecode format as is used
3297 for tracepoint actions.
3299 * The disassemble command now supports: an optional /r modifier, print the
3300 raw instructions in hex as well as in symbolic form, and an optional /m
3301 modifier to print mixed source+assembly.
3303 * Process record and replay
3305 In a architecture environment that supports ``process record and
3306 replay'', ``process record and replay'' target can record a log of
3307 the process execution, and replay it with both forward and reverse
3310 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3311 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3312 set execution-direction {forward|reverse}, for targets that support
3315 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3316 feature is available with a native GDB running on kernel version
3319 * GDB now has support for multi-byte and wide character sets on the
3320 target. Strings whose character type is wchar_t, char16_t, or
3321 char32_t are now correctly printed. GDB supports wide- and unicode-
3322 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3323 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3324 `printf'. This feature requires iconv to work properly; if your
3325 system does not have a working iconv, GDB can use GNU libiconv. See
3326 the installation instructions for more information.
3328 * GDB now supports automatic retrieval of shared library files from
3329 remote targets. To use this feature, specify a system root that begins
3330 with the `remote:' prefix, either via the `set sysroot' command or via
3331 the `--with-sysroot' configure-time option.
3333 * "info sharedlibrary" now takes an optional regex of libraries to show,
3334 and it now reports if a shared library has no debugging information.
3336 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3337 now complete on file names.
3339 * When completing in expressions, gdb will attempt to limit
3340 completions to allowable structure or union fields, where appropriate.
3341 For instance, consider:
3343 # struct example { int f1; double f2; };
3344 # struct example variable;
3347 If the user types TAB at the end of this command line, the available
3348 completions will be "f1" and "f2".
3350 * Inlined functions are now supported. They show up in backtraces, and
3351 the "step", "next", and "finish" commands handle them automatically.
3353 * GDB now supports the token-splicing (##) and stringification (#)
3354 operators when expanding macros. It also supports variable-arity
3357 * GDB now supports inspecting extra signal information, exported by
3358 the new $_siginfo convenience variable. The feature is currently
3359 implemented on linux ARM, i386 and amd64.
3361 * GDB can now display the VFP floating point registers and NEON vector
3362 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3363 can provide these registers (requires Linux 2.6.30 or later). Remote
3364 and simulator targets may also provide them.
3366 * New remote packets
3369 Search memory for a sequence of bytes.
3372 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3373 operation over reliable transport links. Use of this packet is
3374 controlled by the `set remote noack-packet' command.
3377 Kill the process with the specified process ID. Use this in preference
3378 to `k' when multiprocess protocol extensions are supported.
3381 Obtains additional operating system information
3385 Read or write additional signal information.
3387 * Removed remote protocol undocumented extension
3389 An undocumented extension to the remote protocol's `S' stop reply
3390 packet that permited the stub to pass a process id was removed.
3391 Remote servers should use the `T' stop reply packet instead.
3393 * GDB now supports multiple function calling conventions according to the
3394 DWARF-2 DW_AT_calling_convention function attribute.
3396 * The SH target utilizes the aforementioned change to distinguish between gcc
3397 and Renesas calling convention. It also adds the new CLI commands
3398 `set/show sh calling-convention'.
3400 * GDB can now read compressed debug sections, as produced by GNU gold
3401 with the --compress-debug-sections=zlib flag.
3403 * 64-bit core files are now supported on AIX.
3405 * Thread switching is now supported on Tru64.
3407 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3408 which will be allocated using malloc later in program execution.
3410 * The qXfer:libraries:read remote procotol packet now allows passing a
3411 list of section offsets.
3413 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3414 conditions handling signals delivered during attach or thread creation
3415 have also been fixed.
3417 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3418 From the user's standpoint, all unqualified instances of True and False
3419 are treated as the standard definitions, regardless of context.
3421 * GDB now parses C++ symbol and type names more flexibly. For
3424 template<typename T> class C { };
3427 GDB will now correctly handle all of:
3429 ptype C<char const *>
3430 ptype C<char const*>
3431 ptype C<const char *>
3432 ptype C<const char*>
3434 * New features in the GDB remote stub, gdbserver
3436 - The "--wrapper" command-line argument tells gdbserver to use a
3437 wrapper program to launch programs for debugging.
3439 - On PowerPC and S/390 targets, it is now possible to use a single
3440 gdbserver executable to debug both 32-bit and 64-bit programs.
3441 (This requires gdbserver itself to be built as a 64-bit executable.)
3443 - gdbserver uses the new noack protocol mode for TCP connections to
3444 reduce communications latency, if also supported and enabled in GDB.
3446 - Support for the sparc64-linux-gnu target is now included in
3449 - The amd64-linux build of gdbserver now supports debugging both
3450 32-bit and 64-bit programs.
3452 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3453 now support hardware watchpoints, and will use them automatically
3458 GDB now has support for scripting using Python. Whether this is
3459 available is determined at configure time.
3461 New GDB commands can now be written in Python.
3463 * Ada tasking support
3465 Ada tasks can now be inspected in GDB. The following commands have
3469 Print the list of Ada tasks.
3471 Print detailed information about task number N.
3473 Print the task number of the current task.
3475 Switch the context of debugging to task number N.
3477 * Support for user-defined prefixed commands. The "define" command can
3478 add new commands to existing prefixes, e.g. "target".
3480 * Multi-inferior, multi-process debugging.
3482 GDB now has generalized support for multi-inferior debugging. See
3483 "Debugging Multiple Inferiors" in the manual for more information.
3484 Although availability still depends on target support, the command
3485 set is more uniform now. The GNU/Linux specific multi-forks support
3486 has been migrated to this new framework. This implied some user
3487 visible changes; see "New commands" and also "Removed commands"
3490 * Target descriptions can now describe the target OS ABI. See the
3491 "Target Description Format" section in the user manual for more
3494 * Target descriptions can now describe "compatible" architectures
3495 to indicate that the target can execute applications for a different
3496 architecture in addition to those for the main target architecture.
3497 See the "Target Description Format" section in the user manual for
3500 * Multi-architecture debugging.
3502 GDB now includes general supports for debugging applications on
3503 hybrid systems that use more than one single processor architecture
3504 at the same time. Each such hybrid architecture still requires
3505 specific support to be added. The only hybrid architecture supported
3506 in this version of GDB is the Cell Broadband Engine.
3508 * GDB now supports integrated debugging of Cell/B.E. applications that
3509 use both the PPU and SPU architectures. To enable support for hybrid
3510 Cell/B.E. debugging, you need to configure GDB to support both the
3511 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3512 --enable-targets configure option.
3514 * Non-stop mode debugging.
3516 For some targets, GDB now supports an optional mode of operation in
3517 which you can examine stopped threads while other threads continue
3518 to execute freely. This is referred to as non-stop mode, with the
3519 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3520 section in the user manual for more information.
3522 To be able to support remote non-stop debugging, a remote stub needs
3523 to implement the non-stop mode remote protocol extensions, as
3524 described in the "Remote Non-Stop" section of the user manual. The
3525 GDB remote stub, gdbserver, has been adjusted to support these
3526 extensions on linux targets.
3528 * New commands (for set/show, see "New options" below)
3530 catch syscall [NAME(S) | NUMBER(S)]
3531 Catch system calls. Arguments, which should be names of system
3532 calls or their numbers, mean catch only those syscalls. Without
3533 arguments, every syscall will be caught. When the inferior issues
3534 any of the specified syscalls, GDB will stop and announce the system
3535 call, both when it is called and when its call returns. This
3536 feature is currently available with a native GDB running on the
3537 Linux Kernel, under the following architectures: x86, x86_64,
3538 PowerPC and PowerPC64.
3540 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3542 Search memory for a sequence of bytes.
3544 maint set python print-stack
3545 maint show python print-stack
3546 Show a stack trace when an error is encountered in a Python script.
3549 Invoke CODE by passing it to the Python interpreter.
3554 These allow macros to be defined, undefined, and listed
3558 Show operating system information about processes.
3561 List the inferiors currently under GDB's control.
3564 Switch focus to inferior number NUM.
3567 Detach from inferior number NUM.
3570 Kill inferior number NUM.
3574 set spu stop-on-load
3575 show spu stop-on-load
3576 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3578 set spu auto-flush-cache
3579 show spu auto-flush-cache
3580 Control whether to automatically flush the software-managed cache
3581 during Cell/B.E. debugging.
3583 set sh calling-convention
3584 show sh calling-convention
3585 Control the calling convention used when calling SH target functions.
3588 show debug timestamp
3589 Control display of timestamps with GDB debugging output.
3591 set disassemble-next-line
3592 show disassemble-next-line
3593 Control display of disassembled source lines or instructions when
3596 set remote noack-packet
3597 show remote noack-packet
3598 Set/show the use of remote protocol QStartNoAckMode packet. See above
3599 under "New remote packets."
3601 set remote query-attached-packet
3602 show remote query-attached-packet
3603 Control use of remote protocol `qAttached' (query-attached) packet.
3605 set remote read-siginfo-object
3606 show remote read-siginfo-object
3607 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3610 set remote write-siginfo-object
3611 show remote write-siginfo-object
3612 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3615 set remote reverse-continue
3616 show remote reverse-continue
3617 Control use of remote protocol 'bc' (reverse-continue) packet.
3619 set remote reverse-step
3620 show remote reverse-step
3621 Control use of remote protocol 'bs' (reverse-step) packet.
3623 set displaced-stepping
3624 show displaced-stepping
3625 Control displaced stepping mode. Displaced stepping is a way to
3626 single-step over breakpoints without removing them from the debuggee.
3627 Also known as "out-of-line single-stepping".
3630 show debug displaced
3631 Control display of debugging info for displaced stepping.
3633 maint set internal-error
3634 maint show internal-error
3635 Control what GDB does when an internal error is detected.
3637 maint set internal-warning
3638 maint show internal-warning
3639 Control what GDB does when an internal warning is detected.
3644 Use a wrapper program to launch programs for debugging.
3646 set multiple-symbols (all|ask|cancel)
3647 show multiple-symbols
3648 The value of this variable can be changed to adjust the debugger behavior
3649 when an expression or a breakpoint location contains an ambiguous symbol
3650 name (an overloaded function name, for instance).
3652 set breakpoint always-inserted
3653 show breakpoint always-inserted
3654 Keep breakpoints always inserted in the target, as opposed to inserting
3655 them when resuming the target, and removing them when the target stops.
3656 This option can improve debugger performance on slow remote targets.
3658 set arm fallback-mode (arm|thumb|auto)
3659 show arm fallback-mode
3660 set arm force-mode (arm|thumb|auto)
3662 These commands control how ARM GDB determines whether instructions
3663 are ARM or Thumb. The default for both settings is auto, which uses
3664 the current CPSR value for instructions without symbols; previous
3665 versions of GDB behaved as if "set arm fallback-mode arm".
3667 set disable-randomization
3668 show disable-randomization
3669 Standalone programs run with the virtual address space randomization enabled
3670 by default on some platforms. This option keeps the addresses stable across
3671 multiple debugging sessions.
3675 Control whether other threads are stopped or not when some thread hits
3680 Requests that asynchronous execution is enabled in the target, if available.
3681 In this case, it's possible to resume target in the background, and interact
3682 with GDB while the target is running. "show target-async" displays the
3683 current state of asynchronous execution of the target.
3685 set target-wide-charset
3686 show target-wide-charset
3687 The target-wide-charset is the name of the character set that GDB
3688 uses when printing characters whose type is wchar_t.
3690 set tcp auto-retry (on|off)
3692 set tcp connect-timeout
3693 show tcp connect-timeout
3694 These commands allow GDB to retry failed TCP connections to a remote stub
3695 with a specified timeout period; this is useful if the stub is launched
3696 in parallel with GDB but may not be ready to accept connections immediately.
3698 set libthread-db-search-path
3699 show libthread-db-search-path
3700 Control list of directories which GDB will search for appropriate
3703 set schedule-multiple (on|off)
3704 show schedule-multiple
3705 Allow GDB to resume all threads of all processes or only threads of
3706 the current process.
3710 Use more aggressive caching for accesses to the stack. This improves
3711 performance of remote debugging (particularly backtraces) without
3712 affecting correctness.
3714 set interactive-mode (on|off|auto)
3715 show interactive-mode
3716 Control whether GDB runs in interactive mode (on) or not (off).
3717 When in interactive mode, GDB waits for the user to answer all
3718 queries. Otherwise, GDB does not wait and assumes the default
3719 answer. When set to auto (the default), GDB determines which
3720 mode to use based on the stdin settings.
3725 For program forks, this is replaced by the new more generic `info
3726 inferiors' command. To list checkpoints, you can still use the
3727 `info checkpoints' command, which was an alias for the `info forks'
3731 Replaced by the new `inferior' command. To switch between
3732 checkpoints, you can still use the `restart' command, which was an
3733 alias for the `fork' command.
3736 This is removed, since some targets don't have a notion of
3737 processes. To switch between processes, you can still use the
3738 `inferior' command using GDB's own inferior number.
3741 For program forks, this is replaced by the new more generic `kill
3742 inferior' command. To delete a checkpoint, you can still use the
3743 `delete checkpoint' command, which was an alias for the `delete
3747 For program forks, this is replaced by the new more generic `detach
3748 inferior' command. To detach a checkpoint, you can still use the
3749 `detach checkpoint' command, which was an alias for the `detach
3752 * New native configurations
3754 x86/x86_64 Darwin i[34567]86-*-darwin*
3756 x86_64 MinGW x86_64-*-mingw*
3760 Lattice Mico32 lm32-*
3761 x86 DICOS i[34567]86-*-dicos*
3762 x86_64 DICOS x86_64-*-dicos*
3765 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3766 (mingw32ce) debugging.
3772 These commands were actually not implemented on any target.
3774 *** Changes in GDB 6.8
3776 * New native configurations
3778 NetBSD/hppa hppa*-*netbsd*
3779 Xtensa GNU/Linux xtensa*-*-linux*
3783 NetBSD/hppa hppa*-*-netbsd*
3784 Xtensa GNU/Lunux xtensa*-*-linux*
3786 * Change in command line behavior -- corefiles vs. process ids.
3788 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3789 attaching to process NUMBER fails, GDB no longer attempts to open a
3790 core file named NUMBER. Attaching to a program using the -c option
3791 is no longer supported. Instead, use the '-p' or '--pid' options.
3793 * GDB can now be built as a native debugger for debugging Windows x86
3794 (mingw32) Portable Executable (PE) programs.
3796 * Pending breakpoints no longer change their number when their address
3799 * GDB now supports breakpoints with multiple locations,
3800 including breakpoints on C++ constructors, inside C++ templates,
3801 and in inlined functions.
3803 * GDB's ability to debug optimized code has been improved. GDB more
3804 accurately identifies function bodies and lexical blocks that occupy
3805 more than one contiguous range of addresses.
3807 * Target descriptions can now describe registers for PowerPC.
3809 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3810 registers on PowerPC targets.
3812 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3813 targets even when the libthread_db library is not available.
3815 * The GDB remote stub, gdbserver, now supports the new file transfer
3816 commands (remote put, remote get, and remote delete).
3818 * The GDB remote stub, gdbserver, now supports run and attach in
3819 extended-remote mode.
3821 * hppa*64*-*-hpux11* target broken
3822 The debugger is unable to start a program and fails with the following
3823 error: "Error trying to get information about dynamic linker".
3824 The gdb-6.7 release is also affected.
3826 * GDB now supports the --enable-targets= configure option to allow
3827 building a single GDB executable that supports multiple remote
3828 target architectures.
3830 * GDB now supports debugging C and C++ programs which use the
3831 Decimal Floating Point extension. In addition, the PowerPC target
3832 now has a set of pseudo-registers to inspect decimal float values
3833 stored in two consecutive float registers.
3835 * The -break-insert MI command can optionally create pending
3838 * Improved support for debugging Ada
3839 Many improvements to the Ada language support have been made. These
3841 - Better support for Ada2005 interface types
3842 - Improved handling of arrays and slices in general
3843 - Better support for Taft-amendment types
3844 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3846 - Improved command completion in Ada
3849 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3854 set print frame-arguments (all|scalars|none)
3855 show print frame-arguments
3856 The value of this variable can be changed to control which argument
3857 values should be printed by the debugger when displaying a frame.
3862 Transfer files to and from a remote target, and delete remote files.
3869 Transfer files to and from a remote target, and delete remote files.
3871 * New remote packets
3878 Open, close, read, write, and delete files on the remote system.
3881 Attach to an existing process on the remote system, in extended-remote
3885 Run a new process on the remote system, in extended-remote mode.
3887 *** Changes in GDB 6.7
3889 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3890 bfd, libiberty and opcodes, as revealed by static analysis donated by
3891 Coverity, Inc. (http://scan.coverity.com).
3893 * When looking up multiply-defined global symbols, GDB will now prefer the
3894 symbol definition in the current shared library if it was built using the
3895 -Bsymbolic linker option.
3897 * When the Text User Interface (TUI) is not configured, GDB will now
3898 recognize the -tui command-line option and print a message that the TUI
3901 * The GDB remote stub, gdbserver, now has lower overhead for high
3902 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3904 * GDB for MIPS targets now autodetects whether a remote target provides
3905 32-bit or 64-bit register values.
3907 * Support for C++ member pointers has been improved.
3909 * GDB now understands XML target descriptions, which specify the
3910 target's overall architecture. GDB can read a description from
3911 a local file or over the remote serial protocol.
3913 * Vectors of single-byte data use a new integer type which is not
3914 automatically displayed as character or string data.
3916 * The /s format now works with the print command. It displays
3917 arrays of single-byte integers and pointers to single-byte integers
3920 * Target descriptions can now describe target-specific registers,
3921 for architectures which have implemented the support (currently
3922 only ARM, M68K, and MIPS).
3924 * GDB and the GDB remote stub, gdbserver, now support the XScale
3927 * The GDB remote stub, gdbserver, has been updated to support
3928 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3929 has been rewritten to use the standard GDB remote protocol.
3931 * GDB can now step into C++ functions which are called through thunks.
3933 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3935 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3936 layout. It also supports a TextSeg= and DataSeg= response when only
3937 segment base addresses (rather than offsets) are available.
3939 * The /i format now outputs any trailing branch delay slot instructions
3940 immediately following the last instruction within the count specified.
3942 * The GDB remote protocol "T" stop reply packet now supports a
3943 "library" response. Combined with the new "qXfer:libraries:read"
3944 packet, this response allows GDB to debug shared libraries on targets
3945 where the operating system manages the list of loaded libraries (e.g.
3946 Windows and SymbianOS).
3948 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3949 (DLLs) on Windows and Windows CE targets.
3951 * GDB now supports a faster verification that a .debug file matches its binary
3952 according to its build-id signature, if the signature is present.
3958 Enable or disable hardware flow control (RTS/CTS) on the serial port
3959 when debugging using remote targets.
3961 set mem inaccessible-by-default
3962 show mem inaccessible-by-default
3963 If the target supplies a memory map, for instance via the remote
3964 protocol's "qXfer:memory-map:read" packet, setting this variable
3965 prevents GDB from accessing memory outside the memory map. This
3966 is useful for targets with memory mapped registers or which react
3967 badly to accesses of unmapped address space.
3969 set breakpoint auto-hw
3970 show breakpoint auto-hw
3971 If the target supplies a memory map, for instance via the remote
3972 protocol's "qXfer:memory-map:read" packet, setting this variable
3973 lets GDB use hardware breakpoints automatically for memory regions
3974 where it can not use software breakpoints. This covers both the
3975 "break" command and internal breakpoints used for other commands
3976 including "next" and "finish".
3979 catch exception unhandled
3980 Stop the program execution when Ada exceptions are raised.
3983 Stop the program execution when an Ada assertion failed.
3987 Set an alternate system root for target files. This is a more
3988 general version of "set solib-absolute-prefix", which is now
3989 an alias to "set sysroot".
3992 Provide extended SPU facility status information. This set of
3993 commands is available only when debugging the Cell/B.E. SPU
3996 * New native configurations
3998 OpenBSD/sh sh*-*openbsd*
4001 unset tdesc filename
4003 Use the specified local file as an XML target description, and do
4004 not query the target for its built-in description.
4008 OpenBSD/sh sh*-*-openbsd*
4009 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4010 Toshiba Media Processor mep-elf
4012 * New remote packets
4015 Ignore the specified signals; pass them directly to the debugged program
4016 without stopping other threads or reporting them to GDB.
4018 qXfer:features:read:
4019 Read an XML target description from the target, which describes its
4024 Read or write contents of an spufs file on the target system. These
4025 packets are available only on the Cell/B.E. SPU architecture.
4027 qXfer:libraries:read:
4028 Report the loaded shared libraries. Combined with new "T" packet
4029 response, this packet allows GDB to debug shared libraries on
4030 targets where the operating system manages the list of loaded
4031 libraries (e.g. Windows and SymbianOS).
4035 Support for these obsolete configurations has been removed.
4043 i[34567]86-*-lynxos*
4044 i[34567]86-*-netware*
4045 i[34567]86-*-sco3.2v5*
4046 i[34567]86-*-sco3.2v4*
4048 i[34567]86-*-sysv4.2*
4051 i[34567]86-*-unixware2*
4052 i[34567]86-*-unixware*
4061 * Other removed features
4068 Various m68k-only ROM monitors.
4075 Various Renesas ROM monitors and debugging interfaces for SH and
4080 Support for a Macraigor serial interface to on-chip debugging.
4081 GDB does not directly support the newer parallel or USB
4086 A debug information format. The predecessor to DWARF 2 and
4087 DWARF 3, which are still supported.
4089 Support for the HP aCC compiler on HP-UX/PA-RISC
4091 SOM-encapsulated symbolic debugging information, automatic
4092 invocation of pxdb, and the aCC custom C++ ABI. This does not
4093 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4094 with aCC can still be debugged on an assembly level.
4096 MIPS ".pdr" sections
4098 A MIPS-specific format used to describe stack frame layout
4099 in debugging information.
4103 GDB could work with an older version of Guile to debug
4104 the interpreter and Scheme programs running in it.
4106 set mips stack-arg-size
4107 set mips saved-gpreg-size
4109 Use "set mips abi" to control parameter passing for MIPS.
4111 *** Changes in GDB 6.6
4116 Cell Broadband Engine SPU spu-elf
4118 * GDB can now be configured as a cross-debugger targeting native Windows
4119 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4120 running on a Windows system over TCP/IP to debug Windows programs.
4122 * The GDB remote stub, gdbserver, has been updated to support Windows and
4123 Cygwin debugging. Both single-threaded and multi-threaded programs are
4126 * The "set trust-readonly-sections" command works again. This command was
4127 broken in GDB 6.3, 6.4, and 6.5.
4129 * The "load" command now supports writing to flash memory, if the remote
4130 stub provides the required support.
4132 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4133 longer requires symbolic debug information (e.g. DWARF-2).
4138 unset substitute-path
4139 show substitute-path
4140 Manage a list of substitution rules that GDB uses to rewrite the name
4141 of the directories where the sources are located. This can be useful
4142 for instance when the sources were moved to a different location
4143 between compilation and debugging.
4147 Print each CLI command as it is executed. Each command is prefixed with
4148 a number of `+' symbols representing the nesting depth.
4149 The source command now has a `-v' option to enable the same feature.
4153 The ARM Demon monitor support (RDP protocol, "target rdp").
4155 Kernel Object Display, an embedded debugging feature which only worked with
4156 an obsolete version of Cisco IOS.
4158 The 'set download-write-size' and 'show download-write-size' commands.
4160 * New remote packets
4163 Tell a stub about GDB client features, and request remote target features.
4164 The first feature implemented is PacketSize, which allows the target to
4165 specify the size of packets it can handle - to minimize the number of
4166 packets required and improve performance when connected to a remote
4170 Fetch an OS auxilliary vector from the remote stub. This packet is a
4171 more efficient replacement for qPart:auxv:read.
4173 qXfer:memory-map:read:
4174 Fetch a memory map from the remote stub, including information about
4175 RAM, ROM, and flash memory devices.
4180 Erase and program a flash memory device.
4182 * Removed remote packets
4185 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4186 used it, and only gdbserver implemented it.
4188 *** Changes in GDB 6.5
4192 Renesas M32C/M16C m32c-elf
4194 Morpho Technologies ms1 ms1-elf
4198 init-if-undefined Initialize a convenience variable, but
4199 only if it doesn't already have a value.
4201 The following commands are presently only implemented for native GNU/Linux:
4203 checkpoint Save a snapshot of the program state.
4205 restart <n> Return the program state to a
4206 previously saved state.
4208 info checkpoints List currently saved checkpoints.
4210 delete-checkpoint <n> Delete a previously saved checkpoint.
4212 set|show detach-on-fork Tell gdb whether to detach from a newly
4213 forked process, or to keep debugging it.
4215 info forks List forks of the user program that
4216 are available to be debugged.
4218 fork <n> Switch to debugging one of several
4219 forks of the user program that are
4220 available to be debugged.
4222 delete-fork <n> Delete a fork from the list of forks
4223 that are available to be debugged (and
4224 kill the forked process).
4226 detach-fork <n> Delete a fork from the list of forks
4227 that are available to be debugged (and
4228 allow the process to continue).
4232 Morpho Technologies ms2 ms1-elf
4234 * Improved Windows host support
4236 GDB now builds as a cross debugger hosted on i686-mingw32, including
4237 native console support, and remote communications using either
4238 network sockets or serial ports.
4240 * Improved Modula-2 language support
4242 GDB can now print most types in the Modula-2 syntax. This includes:
4243 basic types, set types, record types, enumerated types, range types,
4244 pointer types and ARRAY types. Procedure var parameters are correctly
4245 printed and hexadecimal addresses and character constants are also
4246 written in the Modula-2 syntax. Best results can be obtained by using
4247 GNU Modula-2 together with the -gdwarf-2 command line option.
4251 The ARM rdi-share module.
4253 The Netware NLM debug server.
4255 *** Changes in GDB 6.4
4257 * New native configurations
4259 OpenBSD/arm arm*-*-openbsd*
4260 OpenBSD/mips64 mips64-*-openbsd*
4264 Morpho Technologies ms1 ms1-elf
4266 * New command line options
4268 --batch-silent As for --batch, but totally silent.
4269 --return-child-result The debugger will exist with the same value
4270 the child (debugged) program exited with.
4271 --eval-command COMMAND, -ex COMMAND
4272 Execute a single GDB CLI command. This may be
4273 specified multiple times and in conjunction
4274 with the --command (-x) option.
4276 * Deprecated commands removed
4278 The following commands, that were deprecated in 2000, have been
4282 set|show arm disassembly-flavor set|show arm disassembler
4283 othernames set arm disassembler
4284 set|show remotedebug set|show debug remote
4285 set|show archdebug set|show debug arch
4286 set|show eventdebug set|show debug event
4289 * New BSD user-level threads support
4291 It is now possible to debug programs using the user-level threads
4292 library on OpenBSD and FreeBSD. Currently supported (target)
4295 FreeBSD/amd64 x86_64-*-freebsd*
4296 FreeBSD/i386 i386-*-freebsd*
4297 OpenBSD/i386 i386-*-openbsd*
4299 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4300 are not yet supported.
4302 * New support for Matsushita MN10300 w/sim added
4303 (Work in progress). mn10300-elf.
4305 * REMOVED configurations and files
4307 VxWorks and the XDR protocol *-*-vxworks
4308 Motorola MCORE mcore-*-*
4309 National Semiconductor NS32000 ns32k-*-*
4311 * New "set print array-indexes" command
4313 After turning this setting "on", GDB prints the index of each element
4314 when displaying arrays. The default is "off" to preserve the previous
4317 * VAX floating point support
4319 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4321 * User-defined command support
4323 In addition to using $arg0..$arg9 for argument passing, it is now possible
4324 to use $argc to determine now many arguments have been passed. See the
4325 section on user-defined commands in the user manual for more information.
4327 *** Changes in GDB 6.3:
4329 * New command line option
4331 GDB now accepts -l followed by a number to set the timeout for remote
4334 * GDB works with GCC -feliminate-dwarf2-dups
4336 GDB now supports a more compact representation of DWARF-2 debug
4337 information using DW_FORM_ref_addr references. These are produced
4338 by GCC with the option -feliminate-dwarf2-dups and also by some
4339 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4340 to use -feliminate-dwarf2-dups.
4342 * Internationalization
4344 When supported by the host system, GDB will be built with
4345 internationalization (libintl). The task of marking up the sources is
4346 continued, we're looking forward to our first translation.
4350 Initial support for debugging programs compiled with the GNAT
4351 implementation of the Ada programming language has been integrated
4352 into GDB. In this release, support is limited to expression evaluation.
4354 * New native configurations
4356 GNU/Linux/m32r m32r-*-linux-gnu
4360 GDB's remote protocol now includes support for the 'p' packet. This
4361 packet is used to fetch individual registers from a remote inferior.
4363 * END-OF-LIFE registers[] compatibility module
4365 GDB's internal register infrastructure has been completely rewritten.
4366 The new infrastructure making possible the implementation of key new
4367 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4370 GDB 6.3 will be the last release to include the the registers[]
4371 compatibility module that allowed out-of-date configurations to
4372 continue to work. This change directly impacts the following
4382 powerpc bdm protocol
4384 Unless there is activity to revive these configurations, they will be
4385 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4387 * OBSOLETE configurations and files
4389 Configurations that have been declared obsolete in this release have
4390 been commented out. Unless there is activity to revive these
4391 configurations, the next release of GDB will have their sources
4392 permanently REMOVED.
4401 *** Changes in GDB 6.2.1:
4403 * MIPS `break main; run' gave an heuristic-fence-post warning
4405 When attempting to run even a simple program, a warning about
4406 heuristic-fence-post being hit would be reported. This problem has
4409 * MIPS IRIX 'long double' crashed GDB
4411 When examining a long double variable, GDB would get a segmentation
4412 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4413 IRIX long double values).
4417 A bug in the VAX stack code was causing problems with the "next"
4418 command. This problem has been fixed.
4420 *** Changes in GDB 6.2:
4422 * Fix for ``many threads''
4424 On GNU/Linux systems that use the NPTL threads library, a program
4425 rapidly creating and deleting threads would confuse GDB leading to the
4428 ptrace: No such process.
4429 thread_db_get_info: cannot get thread info: generic error
4431 This problem has been fixed.
4433 * "-async" and "-noasync" options removed.
4435 Support for the broken "-noasync" option has been removed (it caused
4438 * New ``start'' command.
4440 This command runs the program until the begining of the main procedure.
4442 * New BSD Kernel Data Access Library (libkvm) interface
4444 Using ``target kvm'' it is now possible to debug kernel core dumps and
4445 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4446 platforms. Currently supported (native-only) configurations are:
4448 FreeBSD/amd64 x86_64-*-freebsd*
4449 FreeBSD/i386 i?86-*-freebsd*
4450 NetBSD/i386 i?86-*-netbsd*
4451 NetBSD/m68k m68*-*-netbsd*
4452 NetBSD/sparc sparc-*-netbsd*
4453 OpenBSD/amd64 x86_64-*-openbsd*
4454 OpenBSD/i386 i?86-*-openbsd*
4455 OpenBSD/m68k m68*-openbsd*
4456 OpenBSD/sparc sparc-*-openbsd*
4458 * Signal trampoline code overhauled
4460 Many generic problems with GDB's signal handling code have been fixed.
4461 These include: backtraces through non-contiguous stacks; recognition
4462 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4463 call; backtrace through a signal trampoline; step into and out of
4464 signal handlers; and single-stepping in the signal trampoline.
4466 Please note that kernel bugs are a limiting factor here. These
4467 features have been shown to work on an s390 GNU/Linux system that
4468 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4470 * Cygwin support for DWARF 2 added.
4472 * New native configurations
4474 GNU/Linux/hppa hppa*-*-linux*
4475 OpenBSD/hppa hppa*-*-openbsd*
4476 OpenBSD/m68k m68*-*-openbsd*
4477 OpenBSD/m88k m88*-*-openbsd*
4478 OpenBSD/powerpc powerpc-*-openbsd*
4479 NetBSD/vax vax-*-netbsd*
4480 OpenBSD/vax vax-*-openbsd*
4482 * END-OF-LIFE frame compatibility module
4484 GDB's internal frame infrastructure has been completely rewritten.
4485 The new infrastructure making it possible to support key new features
4486 including DWARF 2 Call Frame Information. To aid in the task of
4487 migrating old configurations to this new infrastructure, a
4488 compatibility module, that allowed old configurations to continue to
4489 work, was also included.
4491 GDB 6.2 will be the last release to include this frame compatibility
4492 module. This change directly impacts the following configurations:
4502 Unless there is activity to revive these configurations, they will be
4503 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4505 * REMOVED configurations and files
4507 Sun 3, running SunOS 3 m68*-*-sunos3*
4508 Sun 3, running SunOS 4 m68*-*-sunos4*
4509 Sun 2, running SunOS 3 m68000-*-sunos3*
4510 Sun 2, running SunOS 4 m68000-*-sunos4*
4511 Motorola 680x0 running LynxOS m68*-*-lynxos*
4512 AT&T 3b1/Unix pc m68*-att-*
4513 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4514 decstation mips-dec-* mips-little-*
4515 riscos mips-*-riscos* mips-*-sysv*
4516 sonymips mips-sony-*
4517 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4519 *** Changes in GDB 6.1.1:
4521 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4523 The TUI (Text-mode User Interface) is now built as part of a default
4524 GDB configuration. It is enabled by either selecting the TUI with the
4525 command line option "-i=tui" or by running the separate "gdbtui"
4526 program. For more information on the TUI, see the manual "Debugging
4529 * Pending breakpoint support (also included in GDB 6.1)
4531 Support has been added to allow you to specify breakpoints in shared
4532 libraries that have not yet been loaded. If a breakpoint location
4533 cannot be found, and the "breakpoint pending" option is set to auto,
4534 GDB queries you if you wish to make the breakpoint pending on a future
4535 shared-library load. If and when GDB resolves the breakpoint symbol,
4536 the pending breakpoint is removed as one or more regular breakpoints
4539 Pending breakpoints are very useful for GCJ Java debugging.
4541 * Fixed ISO-C build problems
4543 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4544 non ISO-C code that stopped them being built using a more strict ISO-C
4545 compiler (e.g., IBM's C compiler).
4547 * Fixed build problem on IRIX 5
4549 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4550 wasn't able to compile compile on an IRIX 5 system.
4552 * Added execute permission to gdb/gdbserver/configure
4554 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4555 permission. This bug would cause configure to fail on a number of
4556 systems (Solaris, IRIX). Ref: server/519.
4558 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4560 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4561 has been updated to use constant array sizes.
4563 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4565 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4566 its generated DWARF Call Frame Info. This encoding was causing GDB to
4567 panic, that panic has been fixed. Ref: gdb/1628.
4569 * Fixed a problem when examining parameters in shared library code.
4571 When examining parameters in optimized shared library code generated
4572 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4573 not available''. GDB now correctly displays the variable's value.
4575 *** Changes in GDB 6.1:
4577 * Removed --with-mmalloc
4579 Support for the mmalloc memory manager has been removed, as it
4580 conflicted with the internal gdb byte cache.
4582 * Changes in AMD64 configurations
4584 The AMD64 target now includes the %cs and %ss registers. As a result
4585 the AMD64 remote protocol has changed; this affects the floating-point
4586 and SSE registers. If you rely on those registers for your debugging,
4587 you should upgrade gdbserver on the remote side.
4589 * Revised SPARC target
4591 The SPARC target has been completely revised, incorporating the
4592 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4593 support for LynxOS and SunOS 4 has been dropped. Calling functions
4594 from within GDB on operating systems with a non-executable stack
4595 (Solaris, OpenBSD) now works.
4599 GDB has a new C++ demangler which does a better job on the mangled
4600 names generated by current versions of g++. It also runs faster, so
4601 with this and other changes gdb should now start faster on large C++
4604 * DWARF 2 Location Expressions
4606 GDB support for location expressions has been extended to support function
4607 arguments and frame bases. Older versions of GDB could crash when they
4610 * C++ nested types and namespaces
4612 GDB's support for nested types and namespaces in C++ has been
4613 improved, especially if you use the DWARF 2 debugging format. (This
4614 is the default for recent versions of GCC on most platforms.)
4615 Specifically, if you have a class "Inner" defined within a class or
4616 namespace "Outer", then GDB realizes that the class's name is
4617 "Outer::Inner", not simply "Inner". This should greatly reduce the
4618 frequency of complaints about not finding RTTI symbols. In addition,
4619 if you are stopped at inside of a function defined within a namespace,
4620 GDB modifies its name lookup accordingly.
4622 * New native configurations
4624 NetBSD/amd64 x86_64-*-netbsd*
4625 OpenBSD/amd64 x86_64-*-openbsd*
4626 OpenBSD/alpha alpha*-*-openbsd*
4627 OpenBSD/sparc sparc-*-openbsd*
4628 OpenBSD/sparc64 sparc64-*-openbsd*
4630 * New debugging protocols
4632 M32R with SDI protocol m32r-*-elf*
4634 * "set prompt-escape-char" command deleted.
4636 The command "set prompt-escape-char" has been deleted. This command,
4637 and its very obscure effet on GDB's prompt, was never documented,
4638 tested, nor mentioned in the NEWS file.
4640 * OBSOLETE configurations and files
4642 Configurations that have been declared obsolete in this release have
4643 been commented out. Unless there is activity to revive these
4644 configurations, the next release of GDB will have their sources
4645 permanently REMOVED.
4647 Sun 3, running SunOS 3 m68*-*-sunos3*
4648 Sun 3, running SunOS 4 m68*-*-sunos4*
4649 Sun 2, running SunOS 3 m68000-*-sunos3*
4650 Sun 2, running SunOS 4 m68000-*-sunos4*
4651 Motorola 680x0 running LynxOS m68*-*-lynxos*
4652 AT&T 3b1/Unix pc m68*-att-*
4653 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4654 decstation mips-dec-* mips-little-*
4655 riscos mips-*-riscos* mips-*-sysv*
4656 sonymips mips-sony-*
4657 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4659 * REMOVED configurations and files
4661 SGI Irix-4.x mips-sgi-irix4 or iris4
4662 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4663 Z8000 simulator z8k-zilog-none or z8ksim
4664 Matsushita MN10200 w/simulator mn10200-*-*
4665 H8/500 simulator h8500-hitachi-hms or h8500hms
4666 HP/PA running BSD hppa*-*-bsd*
4667 HP/PA running OSF/1 hppa*-*-osf*
4668 HP/PA Pro target hppa*-*-pro*
4669 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4670 386BSD i[3456]86-*-bsd*
4671 Sequent family i[3456]86-sequent-sysv4*
4672 i[3456]86-sequent-sysv*
4673 i[3456]86-sequent-bsd*
4674 SPARC running LynxOS sparc-*-lynxos*
4675 SPARC running SunOS 4 sparc-*-sunos4*
4676 Tsqware Sparclet sparclet-*-*
4677 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4679 *** Changes in GDB 6.0:
4683 Support for debugging the Objective-C programming language has been
4684 integrated into GDB.
4686 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4688 DWARF 2's Call Frame Information makes available compiler generated
4689 information that more exactly describes the program's run-time stack.
4690 By using this information, GDB is able to provide more robust stack
4693 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4694 have been updated to use a new backtrace mechanism which includes
4695 DWARF 2 CFI support.
4699 GDB's remote protocol has been extended to include support for hosted
4700 file I/O (where the remote target uses GDB's file system). See GDB's
4701 remote protocol documentation for details.
4703 * All targets using the new architecture framework.
4705 All of GDB's targets have been updated to use the new internal
4706 architecture framework. The way is now open for future GDB releases
4707 to include cross-architecture native debugging support (i386 on amd64,
4710 * GNU/Linux's Thread Local Storage (TLS)
4712 GDB now includes support for for the GNU/Linux implementation of
4713 per-thread variables.
4715 * GNU/Linux's Native POSIX Thread Library (NPTL)
4717 GDB's thread code has been updated to work with either the new
4718 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4720 * Separate debug info.
4722 GDB, in conjunction with BINUTILS, now supports a mechanism for
4723 automatically loading debug information from a separate file. Instead
4724 of shipping full debug and non-debug versions of system libraries,
4725 system integrators can now instead ship just the stripped libraries
4726 and optional debug files.
4728 * DWARF 2 Location Expressions
4730 DWARF 2 Location Expressions allow the compiler to more completely
4731 describe the location of variables (even in optimized code) to the
4734 GDB now includes preliminary support for location expressions (support
4735 for DW_OP_piece is still missing).
4739 A number of long standing bugs that caused GDB to die while starting a
4740 Java application have been fixed. GDB's Java support is now
4741 considered "useable".
4743 * GNU/Linux support for fork, vfork, and exec.
4745 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4746 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4749 * GDB supports logging output to a file
4751 There are two new commands, "set logging" and "show logging", which can be
4752 used to capture GDB's output to a file.
4754 * The meaning of "detach" has changed for gdbserver
4756 The "detach" command will now resume the application, as documented. To
4757 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4760 * d10v, m68hc11 `regs' command deprecated
4762 The `info registers' command has been updated so that it displays the
4763 registers using a format identical to the old `regs' command.
4767 A new command, "maint set profile on/off", has been added. This command can
4768 be used to enable or disable profiling while running GDB, to profile a
4769 session or a set of commands. In addition there is a new configure switch,
4770 "--enable-profiling", which will cause GDB to be compiled with profiling
4771 data, for more informative profiling results.
4773 * Default MI syntax changed to "mi2".
4775 The default MI (machine interface) syntax, enabled by the command line
4776 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4777 "mi1", can be enabled by specifying the option "-i=mi1".
4779 Support for the original "mi0" syntax (included in GDB 5.0) has been
4782 Fix for gdb/192: removed extraneous space when displaying frame level.
4783 Fix for gdb/672: update changelist is now output in mi list format.
4784 Fix for gdb/702: a -var-assign that updates the value now shows up
4785 in a subsequent -var-update.
4787 * New native configurations.
4789 FreeBSD/amd64 x86_64-*-freebsd*
4791 * Multi-arched targets.
4793 HP/PA HPUX11 hppa*-*-hpux*
4794 Renesas M32R/D w/simulator m32r-*-elf*
4796 * OBSOLETE configurations and files
4798 Configurations that have been declared obsolete in this release have
4799 been commented out. Unless there is activity to revive these
4800 configurations, the next release of GDB will have their sources
4801 permanently REMOVED.
4803 Z8000 simulator z8k-zilog-none or z8ksim
4804 Matsushita MN10200 w/simulator mn10200-*-*
4805 H8/500 simulator h8500-hitachi-hms or h8500hms
4806 HP/PA running BSD hppa*-*-bsd*
4807 HP/PA running OSF/1 hppa*-*-osf*
4808 HP/PA Pro target hppa*-*-pro*
4809 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4810 Sequent family i[3456]86-sequent-sysv4*
4811 i[3456]86-sequent-sysv*
4812 i[3456]86-sequent-bsd*
4813 Tsqware Sparclet sparclet-*-*
4814 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4816 * REMOVED configurations and files
4819 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4820 IBM AIX PS/2 i[3456]86-*-aix
4821 i386 running Mach 3.0 i[3456]86-*-mach3*
4822 i386 running Mach i[3456]86-*-mach*
4823 i386 running OSF/1 i[3456]86-*osf1mk*
4824 HP/Apollo 68k Family m68*-apollo*-sysv*,
4826 m68*-hp-bsd*, m68*-hp-hpux*
4827 Argonaut Risc Chip (ARC) arc-*-*
4828 Mitsubishi D30V d30v-*-*
4829 Fujitsu FR30 fr30-*-elf*
4830 OS/9000 i[34]86-*-os9k
4831 I960 with MON960 i960-*-coff
4833 * MIPS $fp behavior changed
4835 The convenience variable $fp, for the MIPS, now consistently returns
4836 the address of the current frame's base. Previously, depending on the
4837 context, $fp could refer to either $sp or the current frame's base
4838 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4839 The GNU Source-Level Debugger''.
4841 *** Changes in GDB 5.3:
4843 * GNU/Linux shared library multi-threaded performance improved.
4845 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4846 `/proc', in preference to `ptrace' for memory reads. This may result
4847 in an improvement in the start-up time of multi-threaded, shared
4848 library applications when run under GDB. One GDB user writes: ``loads
4849 shared libs like mad''.
4851 * ``gdbserver'' now supports multi-threaded applications on some targets
4853 Support for debugging multi-threaded applications which use
4854 the GNU/Linux LinuxThreads package has been added for
4855 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4856 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4858 * GDB now supports C/C++ preprocessor macros.
4860 GDB now expands preprocessor macro invocations in C/C++ expressions,
4861 and provides various commands for showing macro definitions and how
4864 The new command `macro expand EXPRESSION' expands any macro
4865 invocations in expression, and shows the result.
4867 The new command `show macro MACRO-NAME' shows the definition of the
4868 macro named MACRO-NAME, and where it was defined.
4870 Most compilers don't include information about macros in the debugging
4871 information by default. In GCC 3.1, for example, you need to compile
4872 your program with the options `-gdwarf-2 -g3'. If the macro
4873 information is present in the executable, GDB will read it.
4875 * Multi-arched targets.
4877 DEC Alpha (partial) alpha*-*-*
4878 DEC VAX (partial) vax-*-*
4880 National Semiconductor NS32000 (partial) ns32k-*-*
4881 Motorola 68000 (partial) m68k-*-*
4882 Motorola MCORE mcore-*-*
4886 Fujitsu FRV architecture added by Red Hat frv*-*-*
4889 * New native configurations
4891 Alpha NetBSD alpha*-*-netbsd*
4892 SH NetBSD sh*-*-netbsdelf*
4893 MIPS NetBSD mips*-*-netbsd*
4894 UltraSPARC NetBSD sparc64-*-netbsd*
4896 * OBSOLETE configurations and files
4898 Configurations that have been declared obsolete in this release have
4899 been commented out. Unless there is activity to revive these
4900 configurations, the next release of GDB will have their sources
4901 permanently REMOVED.
4903 Mitsubishi D30V d30v-*-*
4904 OS/9000 i[34]86-*-os9k
4905 IBM AIX PS/2 i[3456]86-*-aix
4906 Fujitsu FR30 fr30-*-elf*
4907 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4908 Argonaut Risc Chip (ARC) arc-*-*
4909 i386 running Mach 3.0 i[3456]86-*-mach3*
4910 i386 running Mach i[3456]86-*-mach*
4911 i386 running OSF/1 i[3456]86-*osf1mk*
4912 HP/Apollo 68k Family m68*-apollo*-sysv*,
4914 m68*-hp-bsd*, m68*-hp-hpux*
4915 I960 with MON960 i960-*-coff
4917 * OBSOLETE languages
4919 CHILL, a Pascal like language used by telecommunications companies.
4921 * REMOVED configurations and files
4923 AMD 29k family via UDI a29k-amd-udi, udi29k
4924 A29K VxWorks a29k-*-vxworks
4925 AMD 29000 embedded, using EBMON a29k-none-none
4926 AMD 29000 embedded with COFF a29k-none-coff
4927 AMD 29000 embedded with a.out a29k-none-aout
4929 testsuite/gdb.hp/gdb.threads-hp/ directory
4931 * New command "set max-user-call-depth <nnn>"
4933 This command allows the user to limit the call depth of user-defined
4934 commands. The default is 1024.
4936 * Changes in FreeBSD/i386 native debugging.
4938 Support for the "generate-core-file" has been added.
4940 * New commands "dump", "append", and "restore".
4942 These commands allow data to be copied from target memory
4943 to a bfd-format or binary file (dump and append), and back
4944 from a file into memory (restore).
4946 * Improved "next/step" support on multi-processor Alpha Tru64.
4948 The previous single-step mechanism could cause unpredictable problems,
4949 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4950 of a software single-step mechanism prevents this.
4952 *** Changes in GDB 5.2.1:
4960 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4961 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4962 Fix, by Joel Brobecker imported from mainline.
4964 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4965 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4966 Fix, by Fred Fish, imported from mainline.
4968 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4969 Surprisingly enough, it works now.
4970 By Michal Ludvig, imported from mainline.
4972 i386 hardware watchpoint support:
4973 avoid misses on second run for some targets.
4974 By Pierre Muller, imported from mainline.
4976 *** Changes in GDB 5.2:
4978 * New command "set trust-readonly-sections on[off]".
4980 This command is a hint that tells gdb that read-only sections
4981 really are read-only (ie. that their contents will not change).
4982 In this mode, gdb will go to the object file rather than the
4983 target to read memory from read-only sections (such as ".text").
4984 This can be a significant performance improvement on some
4985 (notably embedded) targets.
4987 * New command "generate-core-file" (or "gcore").
4989 This new gdb command allows the user to drop a core file of the child
4990 process state at any time. So far it's been implemented only for
4991 GNU/Linux and Solaris, but should be relatively easily ported to other
4992 hosts. Argument is core file name (defaults to core.<pid>).
4994 * New command line option
4996 GDB now accepts --pid or -p followed by a process id.
4998 * Change in command line behavior -- corefiles vs. process ids.
5000 There is a subtle behavior in the way in which GDB handles
5001 command line arguments. The first non-flag argument is always
5002 a program to debug, but the second non-flag argument may either
5003 be a corefile or a process id. Previously, GDB would attempt to
5004 open the second argument as a corefile, and if that failed, would
5005 issue a superfluous error message and then attempt to attach it as
5006 a process. Now, if the second argument begins with a non-digit,
5007 it will be treated as a corefile. If it begins with a digit,
5008 GDB will attempt to attach it as a process, and if no such process
5009 is found, will then attempt to open it as a corefile.
5011 * Changes in ARM configurations.
5013 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5014 configuration is fully multi-arch.
5016 * New native configurations
5018 ARM NetBSD arm*-*-netbsd*
5019 x86 OpenBSD i[3456]86-*-openbsd*
5020 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5021 Sparc64 running FreeBSD sparc64-*-freebsd*
5025 Sanyo XStormy16 xstormy16-elf
5027 * OBSOLETE configurations and files
5029 Configurations that have been declared obsolete in this release have
5030 been commented out. Unless there is activity to revive these
5031 configurations, the next release of GDB will have their sources
5032 permanently REMOVED.
5034 AMD 29k family via UDI a29k-amd-udi, udi29k
5035 A29K VxWorks a29k-*-vxworks
5036 AMD 29000 embedded, using EBMON a29k-none-none
5037 AMD 29000 embedded with COFF a29k-none-coff
5038 AMD 29000 embedded with a.out a29k-none-aout
5040 testsuite/gdb.hp/gdb.threads-hp/ directory
5042 * REMOVED configurations and files
5044 TI TMS320C80 tic80-*-*
5046 PowerPC Solaris powerpcle-*-solaris*
5047 PowerPC Windows NT powerpcle-*-cygwin32
5048 PowerPC Netware powerpc-*-netware*
5049 Harris/CXUX m88k m88*-harris-cxux*
5050 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5051 ns32k-utek-sysv* ns32k-utek-*
5052 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5053 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5054 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5055 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5056 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5058 * Changes to command line processing
5060 The new `--args' feature can be used to specify command-line arguments
5061 for the inferior from gdb's command line.
5063 * Changes to key bindings
5065 There is a new `operate-and-get-next' function bound to `C-o'.
5067 *** Changes in GDB 5.1.1
5069 Fix compile problem on DJGPP.
5071 Fix a problem with floating-point registers on the i386 being
5074 Fix to stop GDB crashing on .debug_str debug info.
5076 Numerous documentation fixes.
5078 Numerous testsuite fixes.
5080 *** Changes in GDB 5.1:
5082 * New native configurations
5084 Alpha FreeBSD alpha*-*-freebsd*
5085 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5086 MIPS GNU/Linux mips*-*-linux*
5087 MIPS SGI Irix 6.x mips*-sgi-irix6*
5088 ia64 AIX ia64-*-aix*
5089 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5093 Motorola 68HC11 and 68HC12 m68hc11-elf
5095 UltraSparc running GNU/Linux sparc64-*-linux*
5097 * OBSOLETE configurations and files
5099 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5100 Harris/CXUX m88k m88*-harris-cxux*
5101 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5102 ns32k-utek-sysv* ns32k-utek-*
5103 TI TMS320C80 tic80-*-*
5105 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5106 PowerPC Solaris powerpcle-*-solaris*
5107 PowerPC Windows NT powerpcle-*-cygwin32
5108 PowerPC Netware powerpc-*-netware*
5109 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5110 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5111 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5112 Apple Macintosh (MPW) host N/A
5114 stuff.c (Program to stuff files into a specially prepared space in kdb)
5115 kdb-start.c (Main loop for the standalone kernel debugger)
5117 Configurations that have been declared obsolete in this release have
5118 been commented out. Unless there is activity to revive these
5119 configurations, the next release of GDB will have their sources
5120 permanently REMOVED.
5122 * REMOVED configurations and files
5124 Altos 3068 m68*-altos-*
5125 Convex c1-*-*, c2-*-*
5127 ARM RISCix arm-*-* (as host)
5131 * GDB has been converted to ISO C.
5133 GDB's source code has been converted to ISO C. In particular, the
5134 sources are fully protoized, and rely on standard headers being
5139 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5141 * The MI enabled by default.
5143 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5144 revised and enabled by default. Packages which use GDB as a debugging
5145 engine behind a UI or another front end are encouraged to switch to
5146 using the GDB/MI interface, instead of the old annotations interface
5147 which is now deprecated.
5149 * Support for debugging Pascal programs.
5151 GDB now includes support for debugging Pascal programs. The following
5152 main features are supported:
5154 - Pascal-specific data types such as sets;
5156 - automatic recognition of Pascal sources based on file-name
5159 - Pascal-style display of data types, variables, and functions;
5161 - a Pascal expression parser.
5163 However, some important features are not yet supported.
5165 - Pascal string operations are not supported at all;
5167 - there are some problems with boolean types;
5169 - Pascal type hexadecimal constants are not supported
5170 because they conflict with the internal variables format;
5172 - support for Pascal objects and classes is not full yet;
5174 - unlike Pascal, GDB is case-sensitive for symbol names.
5176 * Changes in completion.
5178 Commands such as `shell', `run' and `set args', which pass arguments
5179 to inferior programs, now complete on file names, similar to what
5180 users expect at the shell prompt.
5182 Commands which accept locations, such as `disassemble', `print',
5183 `breakpoint', `until', etc. now complete on filenames as well as
5184 program symbols. Thus, if you type "break foob TAB", and the source
5185 files linked into the programs include `foobar.c', that file name will
5186 be one of the candidates for completion. However, file names are not
5187 considered for completion after you typed a colon that delimits a file
5188 name from a name of a function in that file, as in "break foo.c:bar".
5190 `set demangle-style' completes on available demangling styles.
5192 * New platform-independent commands:
5194 It is now possible to define a post-hook for a command as well as a
5195 hook that runs before the command. For more details, see the
5196 documentation of `hookpost' in the GDB manual.
5198 * Changes in GNU/Linux native debugging.
5200 Support for debugging multi-threaded programs has been completely
5201 revised for all platforms except m68k and sparc. You can now debug as
5202 many threads as your system allows you to have.
5204 Attach/detach is supported for multi-threaded programs.
5206 Support for SSE registers was added for x86. This doesn't work for
5207 multi-threaded programs though.
5209 * Changes in MIPS configurations.
5211 Multi-arch support is enabled for all MIPS configurations.
5213 GDB can now be built as native debugger on SGI Irix 6.x systems for
5214 debugging n32 executables. (Debugging 64-bit executables is not yet
5217 * Unified support for hardware watchpoints in all x86 configurations.
5219 Most (if not all) native x86 configurations support hardware-assisted
5220 breakpoints and watchpoints in a unified manner. This support
5221 implements debug register sharing between watchpoints, which allows to
5222 put a virtually infinite number of watchpoints on the same address,
5223 and also supports watching regions up to 16 bytes with several debug
5226 The new maintenance command `maintenance show-debug-regs' toggles
5227 debugging print-outs in functions that insert, remove, and test
5228 watchpoints and hardware breakpoints.
5230 * Changes in the DJGPP native configuration.
5232 New command ``info dos sysinfo'' displays assorted information about
5233 the CPU, OS, memory, and DPMI server.
5235 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5236 display information about segment descriptors stored in GDT, LDT, and
5239 New commands ``info dos pde'' and ``info dos pte'' display entries
5240 from Page Directory and Page Tables (for now works with CWSDPMI only).
5241 New command ``info dos address-pte'' displays the Page Table entry for
5242 a given linear address.
5244 GDB can now pass command lines longer than 126 characters to the
5245 program being debugged (requires an update to the libdbg.a library
5246 which is part of the DJGPP development kit).
5248 DWARF2 debug info is now supported.
5250 It is now possible to `step' and `next' through calls to `longjmp'.
5252 * Changes in documentation.
5254 All GDB documentation was converted to GFDL, the GNU Free
5255 Documentation License.
5257 Tracepoints-related commands are now fully documented in the GDB
5260 TUI, the Text-mode User Interface, is now documented in the manual.
5262 Tracepoints-related commands are now fully documented in the GDB
5265 The "GDB Internals" manual now has an index. It also includes
5266 documentation of `ui_out' functions, GDB coding standards, x86
5267 hardware watchpoints, and memory region attributes.
5269 * GDB's version number moved to ``version.in''
5271 The Makefile variable VERSION has been replaced by the file
5272 ``version.in''. People creating GDB distributions should update the
5273 contents of this file.
5277 GUD support is now a standard part of the EMACS distribution.
5279 *** Changes in GDB 5.0:
5281 * Improved support for debugging FP programs on x86 targets
5283 Unified and much-improved support for debugging floating-point
5284 programs on all x86 targets. In particular, ``info float'' now
5285 displays the FP registers in the same format on all x86 targets, with
5286 greater level of detail.
5288 * Improvements and bugfixes in hardware-assisted watchpoints
5290 It is now possible to watch array elements, struct members, and
5291 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5292 on x86 targets no longer erroneously trigger when the address is
5295 * Improvements in the native DJGPP version of GDB
5297 The distribution now includes all the scripts and auxiliary files
5298 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5299 machines ``out of the box''.
5301 The DJGPP version can now debug programs that use signals. It is
5302 possible to catch signals that happened in the debuggee, deliver
5303 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5304 would kill the program being debugged.) Programs that hook hardware
5305 interrupts (keyboard, timer, etc.) can also be debugged.
5307 It is now possible to debug DJGPP programs that redirect their
5308 standard handles or switch them to raw (as opposed to cooked) mode, or
5309 even close them. The command ``run < foo > bar'' works as expected,
5310 and ``info terminal'' reports useful information about the debuggee's
5311 terminal, including raw/cooked mode, redirection, etc.
5313 The DJGPP version now uses termios functions for console I/O, which
5314 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5317 DOS-style file names with drive letters are now fully supported by
5320 It is now possible to debug DJGPP programs that switch their working
5321 directory. It is also possible to rerun the debuggee any number of
5322 times without restarting GDB; thus, you can use the same setup,
5323 breakpoints, etc. for many debugging sessions.
5325 * New native configurations
5327 ARM GNU/Linux arm*-*-linux*
5328 PowerPC GNU/Linux powerpc-*-linux*
5332 Motorola MCore mcore-*-*
5333 x86 VxWorks i[3456]86-*-vxworks*
5334 PowerPC VxWorks powerpc-*-vxworks*
5335 TI TMS320C80 tic80-*-*
5337 * OBSOLETE configurations
5339 Altos 3068 m68*-altos-*
5340 Convex c1-*-*, c2-*-*
5342 ARM RISCix arm-*-* (as host)
5345 Configurations that have been declared obsolete will be commented out,
5346 but the code will be left in place. If there is no activity to revive
5347 these configurations before the next release of GDB, the sources will
5348 be permanently REMOVED.
5350 * Gould support removed
5352 Support for the Gould PowerNode and NP1 has been removed.
5354 * New features for SVR4
5356 On SVR4 native platforms (such as Solaris), if you attach to a process
5357 without first loading a symbol file, GDB will now attempt to locate and
5358 load symbols from the running process's executable file.
5360 * Many C++ enhancements
5362 C++ support has been greatly improved. Overload resolution now works properly
5363 in almost all cases. RTTI support is on the way.
5365 * Remote targets can connect to a sub-program
5367 A popen(3) style serial-device has been added. This device starts a
5368 sub-process (such as a stand-alone simulator) and then communicates
5369 with that. The sub-program to run is specified using the syntax
5370 ``|<program> <args>'' vis:
5372 (gdb) set remotedebug 1
5373 (gdb) target extended-remote |mn10300-elf-sim program-args
5375 * MIPS 64 remote protocol
5377 A long standing bug in the mips64 remote protocol where by GDB
5378 expected certain 32 bit registers (ex SR) to be transfered as 32
5379 instead of 64 bits has been fixed.
5381 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5382 added to provide backward compatibility with older versions of GDB.
5384 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5386 The command ``set remotebinarydownload'' command has been replaced by
5387 ``set remote X-packet''. Other commands in ``set remote'' family
5388 include ``set remote P-packet''.
5390 * Breakpoint commands accept ranges.
5392 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5393 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5394 ``tracepoint passcount'' also accepts a range of tracepoints.
5396 * ``apropos'' command added.
5398 The ``apropos'' command searches through command names and
5399 documentation strings, printing out matches, making it much easier to
5400 try to find a command that does what you are looking for.
5404 A new machine oriented interface (MI) has been added to GDB. This
5405 interface is designed for debug environments running GDB as a separate
5406 process. This is part of the long term libGDB project. See the
5407 "GDB/MI" chapter of the GDB manual for further information. It can be
5408 enabled by configuring with:
5410 .../configure --enable-gdbmi
5412 *** Changes in GDB-4.18:
5414 * New native configurations
5416 HP-UX 10.20 hppa*-*-hpux10.20
5417 HP-UX 11.x hppa*-*-hpux11.0*
5418 M68K GNU/Linux m68*-*-linux*
5422 Fujitsu FR30 fr30-*-elf*
5423 Intel StrongARM strongarm-*-*
5424 Mitsubishi D30V d30v-*-*
5426 * OBSOLETE configurations
5428 Gould PowerNode, NP1 np1-*-*, pn-*-*
5430 Configurations that have been declared obsolete will be commented out,
5431 but the code will be left in place. If there is no activity to revive
5432 these configurations before the next release of GDB, the sources will
5433 be permanently REMOVED.
5437 As a compatibility experiment, GDB's source files buildsym.h and
5438 buildsym.c have been converted to pure standard C, no longer
5439 containing any K&R compatibility code. We believe that all systems in
5440 use today either come with a standard C compiler, or have a GCC port
5441 available. If this is not true, please report the affected
5442 configuration to bug-gdb@gnu.org immediately. See the README file for
5443 information about getting a standard C compiler if you don't have one
5448 GDB now uses readline 2.2.
5450 * set extension-language
5452 You can now control the mapping between filename extensions and source
5453 languages by using the `set extension-language' command. For instance,
5454 you can ask GDB to treat .c files as C++ by saying
5455 set extension-language .c c++
5456 The command `info extensions' lists all of the recognized extensions
5457 and their associated languages.
5459 * Setting processor type for PowerPC and RS/6000
5461 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5462 you can use the `set processor' command to specify what variant of the
5463 PowerPC family you are debugging. The command
5467 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5468 following PowerPC and RS6000 variants:
5470 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5471 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5473 403GC IBM PowerPC 403GC
5474 505 Motorola PowerPC 505
5475 860 Motorola PowerPC 860 or 850
5476 601 Motorola PowerPC 601
5477 602 Motorola PowerPC 602
5478 603 Motorola/IBM PowerPC 603 or 603e
5479 604 Motorola PowerPC 604 or 604e
5480 750 Motorola/IBM PowerPC 750 or 750
5482 At the moment, this command just tells GDB what to name the
5483 special-purpose processor registers. Since almost all the affected
5484 registers are inaccessible to user-level programs, this command is
5485 only useful for remote debugging in its present form.
5489 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5490 more extensive support for HP-UX. Added features include shared
5491 library support, kernel threads and hardware watchpoints for 11.00,
5492 support for HP's ANSI C and C++ compilers, and a compatibility mode
5493 for xdb and dbx commands.
5497 HP's donation includes the new concept of catchpoints, which is a
5498 generalization of the old catch command. On HP-UX, it is now possible
5499 to catch exec, fork, and vfork, as well as library loading.
5501 This means that the existing catch command has changed; its first
5502 argument now specifies the type of catch to be set up. See the
5503 output of "help catch" for a list of catchpoint types.
5505 * Debugging across forks
5507 On HP-UX, you can choose which process to debug when a fork() happens
5512 HP has donated a curses-based terminal user interface (TUI). To get
5513 it, build with --enable-tui. Although this can be enabled for any
5514 configuration, at present it only works for native HP debugging.
5516 * GDB remote protocol additions
5518 A new protocol packet 'X' that writes binary data is now available.
5519 Default behavior is to try 'X', then drop back to 'M' if the stub
5520 fails to respond. The settable variable `remotebinarydownload'
5521 allows explicit control over the use of 'X'.
5523 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5524 full 64-bit address. The command
5526 set remoteaddresssize 32
5528 can be used to revert to the old behaviour. For existing remote stubs
5529 the change should not be noticed, as the additional address information
5532 In order to assist in debugging stubs, you may use the maintenance
5533 command `packet' to send any text string to the stub. For instance,
5535 maint packet heythere
5537 sends the packet "$heythere#<checksum>". Note that it is very easy to
5538 disrupt a debugging session by sending the wrong packet at the wrong
5541 The compare-sections command allows you to compare section data on the
5542 target to what is in the executable file without uploading or
5543 downloading, by comparing CRC checksums.
5545 * Tracing can collect general expressions
5547 You may now collect general expressions at tracepoints. This requires
5548 further additions to the target-side stub; see tracepoint.c and
5549 doc/agentexpr.texi for further details.
5551 * mask-address variable for Mips
5553 For Mips targets, you may control the zeroing of the upper 32 bits of
5554 a 64-bit address by entering `set mask-address on'. This is mainly
5555 of interest to users of embedded R4xxx and R5xxx processors.
5557 * Higher serial baud rates
5559 GDB's serial code now allows you to specify baud rates 57600, 115200,
5560 230400, and 460800 baud. (Note that your host system may not be able
5561 to achieve all of these rates.)
5565 The i960 configuration now includes an initial implementation of a
5566 builtin simulator, contributed by Jim Wilson.
5569 *** Changes in GDB-4.17:
5571 * New native configurations
5573 Alpha GNU/Linux alpha*-*-linux*
5574 Unixware 2.x i[3456]86-unixware2*
5575 Irix 6.x mips*-sgi-irix6*
5576 PowerPC GNU/Linux powerpc-*-linux*
5577 PowerPC Solaris powerpcle-*-solaris*
5578 Sparc GNU/Linux sparc-*-linux*
5579 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5583 Argonaut Risc Chip (ARC) arc-*-*
5584 Hitachi H8/300S h8300*-*-*
5585 Matsushita MN10200 w/simulator mn10200-*-*
5586 Matsushita MN10300 w/simulator mn10300-*-*
5587 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5588 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5589 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5590 Mitsubishi D10V w/simulator d10v-*-*
5591 Mitsubishi M32R/D w/simulator m32r-*-elf*
5592 Tsqware Sparclet sparclet-*-*
5593 NEC V850 w/simulator v850-*-*
5595 * New debugging protocols
5597 ARM with RDI protocol arm*-*-*
5598 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5599 DDB and LSI variants of PMON protocol mips*-*-*
5600 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5601 PowerPC with SDS protocol powerpc{,le}-*-eabi
5602 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5606 All configurations can now understand and use the DWARF 2 debugging
5607 format. The choice is automatic, if the symbol file contains DWARF 2
5612 GDB now includes basic Java language support. This support is
5613 only useful with Java compilers that produce native machine code.
5615 * solib-absolute-prefix and solib-search-path
5617 For SunOS and SVR4 shared libraries, you may now set the prefix for
5618 loading absolute shared library symbol files, and the search path for
5619 locating non-absolute shared library symbol files.
5621 * Live range splitting
5623 GDB can now effectively debug code for which GCC has performed live
5624 range splitting as part of its optimization. See gdb/doc/LRS for
5625 more details on the expected format of the stabs information.
5629 GDB's support for the GNU Hurd, including thread debugging, has been
5630 updated to work with current versions of the Hurd.
5634 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5635 instruction set. ARM GDB automatically detects when Thumb
5636 instructions are in use, and adjusts disassembly and backtracing
5641 GDB's MIPS target configurations now handle the MIP16 16-bit
5646 GDB now includes support for overlays; if an executable has been
5647 linked such that multiple sections are based at the same address, GDB
5648 will decide which section to use for symbolic info. You can choose to
5649 control the decision manually, using overlay commands, or implement
5650 additional target-side support and use "overlay load-target" to bring
5651 in the overlay mapping. Do "help overlay" for more detail.
5655 The command "info symbol <address>" displays information about
5656 the symbol at the specified address.
5660 The standard remote protocol now includes an extension that allows
5661 asynchronous collection and display of trace data. This requires
5662 extensive support in the target-side debugging stub. Tracing mode
5663 includes a new interaction mode in GDB and new commands: see the
5664 file tracepoint.c for more details.
5668 Configurations for embedded MIPS now include a simulator contributed
5669 by Cygnus Solutions. The simulator supports the instruction sets
5670 of most MIPS variants.
5674 Sparc configurations may now include the ERC32 simulator contributed
5675 by the European Space Agency. The simulator is not built into
5676 Sparc targets by default; configure with --enable-sim to include it.
5680 For target configurations that may include multiple variants of a
5681 basic architecture (such as MIPS and SH), you may now set the
5682 architecture explicitly. "set arch" sets, "info arch" lists
5683 the possible architectures.
5685 *** Changes in GDB-4.16:
5687 * New native configurations
5689 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5690 M68K NetBSD m68k-*-netbsd*
5691 PowerPC AIX 4.x powerpc-*-aix*
5692 PowerPC MacOS powerpc-*-macos*
5693 PowerPC Windows NT powerpcle-*-cygwin32
5694 RS/6000 AIX 4.x rs6000-*-aix4*
5698 ARM with RDP protocol arm-*-*
5699 I960 with MON960 i960-*-coff
5700 MIPS VxWorks mips*-*-vxworks*
5701 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5702 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5704 Matra Sparclet sparclet-*-*
5708 The powerpc-eabi configuration now includes the PSIM simulator,
5709 contributed by Andrew Cagney, with assistance from Mike Meissner.
5710 PSIM is a very elaborate model of the PowerPC, including not only
5711 basic instruction set execution, but also details of execution unit
5712 performance and I/O hardware. See sim/ppc/README for more details.
5716 GDB now works with Solaris 2.5.
5718 * Windows 95/NT native
5720 GDB will now work as a native debugger on Windows 95 and Windows NT.
5721 To build it from source, you must use the "gnu-win32" environment,
5722 which uses a DLL to emulate enough of Unix to run the GNU tools.
5723 Further information, binaries, and sources are available at
5724 ftp.cygnus.com, under pub/gnu-win32.
5726 * dont-repeat command
5728 If a user-defined command includes the command `dont-repeat', then the
5729 command will not be repeated if the user just types return. This is
5730 useful if the command is time-consuming to run, so that accidental
5731 extra keystrokes don't run the same command many times.
5733 * Send break instead of ^C
5735 The standard remote protocol now includes an option to send a break
5736 rather than a ^C to the target in order to interrupt it. By default,
5737 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5739 * Remote protocol timeout
5741 The standard remote protocol includes a new variable `remotetimeout'
5742 that allows you to set the number of seconds before GDB gives up trying
5743 to read from the target. The default value is 2.
5745 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5747 By default GDB will automatically keep track of objects as they are
5748 loaded and unloaded by the dynamic linker. By using the command `set
5749 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5750 when shared library events occur, thus allowing you to set breakpoints
5751 in shared libraries which are explicitly loaded by the inferior.
5753 Note this feature does not work on hpux8. On hpux9 you must link
5754 /usr/lib/end.o into your program. This feature should work
5755 automatically on hpux10.
5757 * Irix 5.x hardware watchpoint support
5759 Irix 5 configurations now support the use of hardware watchpoints.
5761 * Mips protocol "SYN garbage limit"
5763 When debugging a Mips target using the `target mips' protocol, you
5764 may set the number of characters that GDB will ignore by setting
5765 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5766 every character. The default value is 1050.
5768 * Recording and replaying remote debug sessions
5770 If you set `remotelogfile' to the name of a file, gdb will write to it
5771 a recording of a remote debug session. This recording may then be
5772 replayed back to gdb using "gdbreplay". See gdbserver/README for
5773 details. This is useful when you have a problem with GDB while doing
5774 remote debugging; you can make a recording of the session and send it
5775 to someone else, who can then recreate the problem.
5777 * Speedups for remote debugging
5779 GDB includes speedups for downloading and stepping MIPS systems using
5780 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5781 and more efficient S-record downloading.
5783 * Memory use reductions and statistics collection
5785 GDB now uses less memory and reports statistics about memory usage.
5786 Try the `maint print statistics' command, for example.
5788 *** Changes in GDB-4.15:
5790 * Psymtabs for XCOFF
5792 The symbol reader for AIX GDB now uses partial symbol tables. This
5793 can greatly improve startup time, especially for large executables.
5795 * Remote targets use caching
5797 Remote targets now use a data cache to speed up communication with the
5798 remote side. The data cache could lead to incorrect results because
5799 it doesn't know about volatile variables, thus making it impossible to
5800 debug targets which use memory mapped I/O devices. `set remotecache
5801 off' turns the the data cache off.
5803 * Remote targets may have threads
5805 The standard remote protocol now includes support for multiple threads
5806 in the target system, using new protocol commands 'H' and 'T'. See
5807 gdb/remote.c for details.
5811 If GDB is configured with `--enable-netrom', then it will include
5812 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5813 acts as though it is a bank of ROM on the target board, but you can
5814 write into it over the network. GDB's support consists only of
5815 support for fast loading into the emulated ROM; to debug, you must use
5816 another protocol, such as standard remote protocol. The usual
5817 sequence is something like
5819 target nrom <netrom-hostname>
5821 target remote <netrom-hostname>:1235
5825 GDB now includes support for the Apple Macintosh, as a host only. It
5826 may be run as either an MPW tool or as a standalone application, and
5827 it can debug through the serial port. All the usual GDB commands are
5828 available, but to the target command, you must supply "serial" as the
5829 device type instead of "/dev/ttyXX". See mpw-README in the main
5830 directory for more information on how to build. The MPW configuration
5831 scripts */mpw-config.in support only a few targets, and only the
5832 mips-idt-ecoff target has been tested.
5836 GDB configuration now uses autoconf. This is not user-visible,
5837 but does simplify configuration and building.
5841 GDB now supports hpux10.
5843 *** Changes in GDB-4.14:
5845 * New native configurations
5847 x86 FreeBSD i[345]86-*-freebsd
5848 x86 NetBSD i[345]86-*-netbsd
5849 NS32k NetBSD ns32k-*-netbsd
5850 Sparc NetBSD sparc-*-netbsd
5854 A29K VxWorks a29k-*-vxworks
5855 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5856 CPU32 EST-300 emulator m68*-*-est*
5857 PowerPC ELF powerpc-*-elf
5860 * Alpha OSF/1 support for procfs
5862 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5863 possible to attach to running processes. As the mounting of the /proc
5864 filesystem is optional on the Alpha, GDB automatically determines
5865 the availability of /proc during startup. This can lead to problems
5866 if /proc is unmounted after GDB has been started.
5868 * Arguments to user-defined commands
5870 User commands may accept up to 10 arguments separated by whitespace.
5871 Arguments are accessed within the user command via $arg0..$arg9. A
5874 print $arg0 + $arg1 + $arg2
5876 To execute the command use:
5879 Defines the command "adder" which prints the sum of its three arguments.
5880 Note the arguments are text substitutions, so they may reference variables,
5881 use complex expressions, or even perform inferior function calls.
5883 * New `if' and `while' commands
5885 This makes it possible to write more sophisticated user-defined
5886 commands. Both commands take a single argument, which is the
5887 expression to evaluate, and must be followed by the commands to
5888 execute, one per line, if the expression is nonzero, the list being
5889 terminated by the word `end'. The `if' command list may include an
5890 `else' word, which causes the following commands to be executed only
5891 if the expression is zero.
5893 * Fortran source language mode
5895 GDB now includes partial support for Fortran 77. It will recognize
5896 Fortran programs and can evaluate a subset of Fortran expressions, but
5897 variables and functions may not be handled correctly. GDB will work
5898 with G77, but does not yet know much about symbols emitted by other
5901 * Better HPUX support
5903 Most debugging facilities now work on dynamic executables for HPPAs
5904 running hpux9 or later. You can attach to running dynamically linked
5905 processes, but by default the dynamic libraries will be read-only, so
5906 for instance you won't be able to put breakpoints in them. To change
5907 that behavior do the following before running the program:
5913 This will cause the libraries to be mapped private and read-write.
5914 To revert to the normal behavior, do this:
5920 You cannot set breakpoints or examine data in the library until after
5921 the library is loaded if the function/data symbols do not have
5924 GDB can now also read debug symbols produced by the HP C compiler on
5925 HPPAs (sorry, no C++, Fortran or 68k support).
5927 * Target byte order now dynamically selectable
5929 You can choose which byte order to use with a target system, via the
5930 commands "set endian big" and "set endian little", and you can see the
5931 current setting by using "show endian". You can also give the command
5932 "set endian auto", in which case GDB will use the byte order
5933 associated with the executable. Currently, only embedded MIPS
5934 configurations support dynamic selection of target byte order.
5936 * New DOS host serial code
5938 This version uses DPMI interrupts to handle buffered I/O, so you
5939 no longer need to run asynctsr when debugging boards connected to
5942 *** Changes in GDB-4.13:
5944 * New "complete" command
5946 This lists all the possible completions for the rest of the line, if it
5947 were to be given as a command itself. This is intended for use by emacs.
5949 * Trailing space optional in prompt
5951 "set prompt" no longer adds a space for you after the prompt you set. This
5952 allows you to set a prompt which ends in a space or one that does not.
5954 * Breakpoint hit counts
5956 "info break" now displays a count of the number of times the breakpoint
5957 has been hit. This is especially useful in conjunction with "ignore"; you
5958 can ignore a large number of breakpoint hits, look at the breakpoint info
5959 to see how many times the breakpoint was hit, then run again, ignoring one
5960 less than that number, and this will get you quickly to the last hit of
5963 * Ability to stop printing at NULL character
5965 "set print null-stop" will cause GDB to stop printing the characters of
5966 an array when the first NULL is encountered. This is useful when large
5967 arrays actually contain only short strings.
5969 * Shared library breakpoints
5971 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5972 breakpoints in shared libraries before the executable is run.
5974 * Hardware watchpoints
5976 There is a new hardware breakpoint for the watch command for sparclite
5977 targets. See gdb/sparclite/hw_breakpoint.note.
5979 Hardware watchpoints are also now supported under GNU/Linux.
5983 Annotations have been added. These are for use with graphical interfaces,
5984 and are still experimental. Currently only gdba.el uses these.
5986 * Improved Irix 5 support
5988 GDB now works properly with Irix 5.2.
5990 * Improved HPPA support
5992 GDB now works properly with the latest GCC and GAS.
5994 * New native configurations
5996 Sequent PTX4 i[34]86-sequent-ptx4
5997 HPPA running OSF/1 hppa*-*-osf*
5998 Atari TT running SVR4 m68*-*-sysv4*
5999 RS/6000 LynxOS rs6000-*-lynxos*
6003 OS/9000 i[34]86-*-os9k
6004 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6007 * Hitachi SH7000 and E7000-PC ICE support
6009 There is now support for communicating with the Hitachi E7000-PC ICE.
6010 This is available automatically when GDB is configured for the SH.
6014 As usual, a variety of small fixes and improvements, both generic
6015 and configuration-specific. See the ChangeLog for more detail.
6017 *** Changes in GDB-4.12:
6019 * Irix 5 is now supported
6023 GDB-4.12 on the HPPA has a number of changes which make it unable
6024 to debug the output from the currently released versions of GCC and
6025 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6026 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6027 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6030 *** Changes in GDB-4.11:
6032 * User visible changes:
6036 The "set remotedebug" option is now consistent between the mips remote
6037 target, remote targets using the gdb-specific protocol, UDI (AMD's
6038 debug protocol for the 29k) and the 88k bug monitor. It is now an
6039 integer specifying a debug level (normally 0 or 1, but 2 means more
6040 debugging info for the mips target).
6042 * DEC Alpha native support
6044 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6045 debug info, but GDB works fairly well with the DEC compiler and should
6046 work with a future GCC release. See the README file for a few
6047 Alpha-specific notes.
6049 * Preliminary thread implementation
6051 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6053 * LynxOS native and target support for 386
6055 This release has been hosted on LynxOS 2.2, and also can be configured
6056 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6059 * Improvements in C++ mangling/demangling.
6061 This release has much better g++ debugging, specifically in name
6062 mangling/demangling, virtual function calls, print virtual table,
6063 call methods, ...etc.
6065 *** Changes in GDB-4.10:
6067 * User visible changes:
6069 Remote debugging using the GDB-specific (`target remote') protocol now
6070 supports the `load' command. This is only useful if you have some
6071 other way of getting the stub to the target system, and you can put it
6072 somewhere in memory where it won't get clobbered by the download.
6074 Filename completion now works.
6076 When run under emacs mode, the "info line" command now causes the
6077 arrow to point to the line specified. Also, "info line" prints
6078 addresses in symbolic form (as well as hex).
6080 All vxworks based targets now support a user settable option, called
6081 vxworks-timeout. This option represents the number of seconds gdb
6082 should wait for responses to rpc's. You might want to use this if
6083 your vxworks target is, perhaps, a slow software simulator or happens
6084 to be on the far side of a thin network line.
6088 This release contains support for using a DEC alpha as a GDB host for
6089 cross debugging. Native alpha debugging is not supported yet.
6092 *** Changes in GDB-4.9:
6096 This is the first GDB release which is accompanied by a matching testsuite.
6097 The testsuite requires installation of dejagnu, which should be available
6098 via ftp from most sites that carry GNU software.
6102 'Cfront' style demangling has had its name changed to 'ARM' style, to
6103 emphasize that it was written from the specifications in the C++ Annotated
6104 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6105 disclaimers, it still generated too much confusion with users attempting to
6106 use gdb with AT&T cfront.
6110 GDB now uses a standard remote interface to a simulator library.
6111 So far, the library contains simulators for the Zilog Z8001/2, the
6112 Hitachi H8/300, H8/500 and Super-H.
6114 * New targets supported
6116 H8/300 simulator h8300-hitachi-hms or h8300hms
6117 H8/500 simulator h8500-hitachi-hms or h8500hms
6118 SH simulator sh-hitachi-hms or sh
6119 Z8000 simulator z8k-zilog-none or z8ksim
6120 IDT MIPS board over serial line mips-idt-ecoff
6122 Cross-debugging to GO32 targets is supported. It requires a custom
6123 version of the i386-stub.c module which is integrated with the
6124 GO32 memory extender.
6126 * New remote protocols
6128 MIPS remote debugging protocol.
6130 * New source languages supported
6132 This version includes preliminary support for Chill, a Pascal like language
6133 used by telecommunications companies. Chill support is also being integrated
6134 into the GNU compiler, but we don't know when it will be publically available.
6137 *** Changes in GDB-4.8:
6139 * HP Precision Architecture supported
6141 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6142 version of this support was available as a set of patches from the
6143 University of Utah. GDB does not support debugging of programs
6144 compiled with the HP compiler, because HP will not document their file
6145 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6146 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6148 Many problems in the preliminary version have been fixed.
6150 * Faster and better demangling
6152 We have improved template demangling and fixed numerous bugs in the GNU style
6153 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6154 character types (wchar_t) are now supported. Demangling of each symbol is now
6155 only done once, and is cached when the symbol table for a file is read in.
6156 This results in a small increase in memory usage for C programs, a moderate
6157 increase in memory usage for C++ programs, and a fantastic speedup in
6160 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6161 from the specifications in the Annotated Reference Manual, which AT&T's
6162 compiler does not actually implement.
6164 * G++ multiple inheritance compiler problem
6166 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6167 inheritance lattices was reworked to properly discover ambiguities. We
6168 recently found an example which causes this new algorithm to fail in a
6169 very subtle way, producing bad debug information for those classes.
6170 The file 'gcc.patch' (in this directory) can be applied to gcc to
6171 circumvent the problem. A future GCC release will contain a complete
6174 The previous G++ debug info problem (mentioned below for the gdb-4.7
6175 release) is fixed in gcc version 2.3.2.
6177 * Improved configure script
6179 The `configure' script will now attempt to guess your system type if
6180 you don't supply a host system type. The old scheme of supplying a
6181 host system triplet is preferable over using this. All the magic is
6182 done in the new `config.guess' script. Examine it for details.
6184 We have also brought our configure script much more in line with the FSF's
6185 version. It now supports the --with-xxx options. In particular,
6186 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6187 The resulting GDB will not be able to read arbitrary object file formats --
6188 only the format ``expected'' to be used on the configured target system.
6189 We hope to make this the default in a future release.
6191 * Documentation improvements
6193 There's new internal documentation on how to modify GDB, and how to
6194 produce clean changes to the code. We implore people to read it
6195 before submitting changes.
6197 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6198 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6199 `info' files are also provided. To build `info' files from scratch,
6200 you will need the latest `makeinfo' release, which will be available in
6201 a future texinfo-X.Y release.
6203 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6204 We're not sure exactly which versions have this problem, but it has
6205 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6206 or better. If that isn't possible, there is a patch in
6207 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6208 around this problem.
6212 GDB now supports array constants that can be used in expressions typed in by
6213 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6214 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6217 The new directory `gdb/sparclite' contains a program that demonstrates
6218 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6220 * New native hosts supported
6222 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6223 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6225 * New targets supported
6227 AMD 29k family via UDI a29k-amd-udi or udi29k
6229 * New file formats supported
6231 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6232 HPUX core files, and SCO 3.2v2 core files.
6236 Attaching to processes now works again; thanks for the many bug reports.
6238 We have also stomped on a bunch of core dumps caused by
6239 printf_filtered("%s") problems.
6241 We eliminated a copyright problem on the rpc and ptrace header files
6242 for VxWorks, which was discovered at the last minute during the 4.7
6243 release. You should now be able to build a VxWorks GDB.
6245 You can now interrupt gdb while an attached process is running. This
6246 will cause the attached process to stop, and give control back to GDB.
6248 We fixed problems caused by using too many file descriptors
6249 for reading symbols from object files and libraries. This was
6250 especially a problem for programs that used many (~100) shared
6253 The `step' command now only enters a subroutine if there is line number
6254 information for the subroutine. Otherwise it acts like the `next'
6255 command. Previously, `step' would enter subroutines if there was
6256 any debugging information about the routine. This avoids problems
6257 when using `cc -g1' on MIPS machines.
6259 * Internal improvements
6261 GDB's internal interfaces have been improved to make it easier to support
6262 debugging of multiple languages in the future.
6264 GDB now uses a common structure for symbol information internally.
6265 Minimal symbols (derived from linkage symbols in object files), partial
6266 symbols (from a quick scan of debug information), and full symbols
6267 contain a common subset of information, making it easier to write
6268 shared code that handles any of them.
6270 * New command line options
6272 We now accept --silent as an alias for --quiet.
6276 The memory-mapped-malloc library is now licensed under the GNU Library
6277 General Public License.
6279 *** Changes in GDB-4.7:
6281 * Host/native/target split
6283 GDB has had some major internal surgery to untangle the support for
6284 hosts and remote targets. Now, when you configure GDB for a remote
6285 target, it will no longer load in all of the support for debugging
6286 local programs on the host. When fully completed and tested, this will
6287 ensure that arbitrary host/target combinations are possible.
6289 The primary conceptual shift is to separate the non-portable code in
6290 GDB into three categories. Host specific code is required any time GDB
6291 is compiled on that host, regardless of the target. Target specific
6292 code relates to the peculiarities of the target, but can be compiled on
6293 any host. Native specific code is everything else: it can only be
6294 built when the host and target are the same system. Child process
6295 handling and core file support are two common `native' examples.
6297 GDB's use of /proc for controlling Unix child processes is now cleaner.
6298 It has been split out into a single module under the `target_ops' vector,
6299 plus two native-dependent functions for each system that uses /proc.
6301 * New hosts supported
6303 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6304 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6305 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6307 * New targets supported
6309 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6310 68030 and CPU32 m68030-*-*, m68332-*-*
6312 * New native hosts supported
6314 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6315 (386bsd is not well tested yet)
6316 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6318 * New file formats supported
6320 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6321 supports reading of `a.out.adobe' object files, which are an a.out
6322 format extended with minimal information about multiple sections.
6326 `show copying' is the same as the old `info copying'.
6327 `show warranty' is the same as `info warrantee'.
6328 These were renamed for consistency. The old commands continue to work.
6330 `info handle' is a new alias for `info signals'.
6332 You can now define pre-command hooks, which attach arbitrary command
6333 scripts to any command. The commands in the hook will be executed
6334 prior to the user's command. You can also create a hook which will be
6335 executed whenever the program stops. See gdb.texinfo.
6339 We now deal with Cfront style name mangling, and can even extract type
6340 info from mangled symbols. GDB can automatically figure out which
6341 symbol mangling style your C++ compiler uses.
6343 Calling of methods and virtual functions has been improved as well.
6347 The crash that occured when debugging Sun Ansi-C compiled binaries is
6348 fixed. This was due to mishandling of the extra N_SO stabs output
6351 We also finally got Ultrix 4.2 running in house, and fixed core file
6352 support, with help from a dozen people on the net.
6354 John M. Farrell discovered that the reason that single-stepping was so
6355 slow on all of the Mips based platforms (primarily SGI and DEC) was
6356 that we were trying to demangle and lookup a symbol used for internal
6357 purposes on every instruction that was being stepped through. Changing
6358 the name of that symbol so that it couldn't be mistaken for a C++
6359 mangled symbol sped things up a great deal.
6361 Rich Pixley sped up symbol lookups in general by getting much smarter
6362 about when C++ symbol mangling is necessary. This should make symbol
6363 completion (TAB on the command line) much faster. It's not as fast as
6364 we'd like, but it's significantly faster than gdb-4.6.
6368 A new user controllable variable 'call_scratch_address' can
6369 specify the location of a scratch area to be used when GDB
6370 calls a function in the target. This is necessary because the
6371 usual method of putting the scratch area on the stack does not work
6372 in systems that have separate instruction and data spaces.
6374 We integrated changes to support the 29k UDI (Universal Debugger
6375 Interface), but discovered at the last minute that we didn't have all
6376 of the appropriate copyright paperwork. We are working with AMD to
6377 resolve this, and hope to have it available soon.
6381 We have sped up the remote serial line protocol, especially for targets
6382 with lots of registers. It now supports a new `expedited status' ('T')
6383 message which can be used in place of the existing 'S' status message.
6384 This allows the remote stub to send only the registers that GDB
6385 needs to make a quick decision about single-stepping or conditional
6386 breakpoints, eliminating the need to fetch the entire register set for
6387 each instruction being stepped through.
6389 The GDB remote serial protocol now implements a write-through cache for
6390 registers, only re-reading the registers if the target has run.
6392 There is also a new remote serial stub for SPARC processors. You can
6393 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6394 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6395 processor with a serial port.
6399 Configure.in files have become much easier to read and modify. A new
6400 `table driven' format makes it more obvious what configurations are
6401 supported, and what files each one uses.
6405 There is a new opcodes library which will eventually contain all of the
6406 disassembly routines and opcode tables. At present, it only contains
6407 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6408 disassembler (binutils/objdump) to share these routines.
6410 The libiberty library is now copylefted under the GNU Library General
6411 Public License. This allows more liberal use, and was done so libg++
6412 can use it. This makes no difference to GDB, since the Library License
6413 grants all the rights from the General Public License.
6417 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6418 reference to the stabs symbol info used by the debugger. It is (as far
6419 as we know) the only published document on this fascinating topic. We
6420 encourage you to read it, compare it to the stabs information on your
6421 system, and send improvements on the document in general (to
6422 bug-gdb@prep.ai.mit.edu).
6424 And, of course, many bugs have been fixed.
6427 *** Changes in GDB-4.6:
6429 * Better support for C++ function names
6431 GDB now accepts as input the "demangled form" of C++ overloaded function
6432 names and member function names, and can do command completion on such names
6433 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6434 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6435 Make use of command completion, it is your friend.
6437 GDB also now accepts a variety of C++ mangled symbol formats. They are
6438 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6439 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6440 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6441 for the list of formats.
6443 * G++ symbol mangling problem
6445 Recent versions of gcc have a bug in how they emit debugging information for
6446 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6447 directory) can be applied to gcc to fix the problem. Alternatively, if you
6448 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6449 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6450 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6453 * New 'maintenance' command
6455 All of the commands related to hacking GDB internals have been moved out of
6456 the main command set, and now live behind the 'maintenance' command. This
6457 can also be abbreviated as 'mt'. The following changes were made:
6459 dump-me -> maintenance dump-me
6460 info all-breakpoints -> maintenance info breakpoints
6461 printmsyms -> maintenance print msyms
6462 printobjfiles -> maintenance print objfiles
6463 printpsyms -> maintenance print psymbols
6464 printsyms -> maintenance print symbols
6466 The following commands are new:
6468 maintenance demangle Call internal GDB demangler routine to
6469 demangle a C++ link name and prints the result.
6470 maintenance print type Print a type chain for a given symbol
6472 * Change to .gdbinit file processing
6474 We now read the $HOME/.gdbinit file before processing the argv arguments
6475 (e.g. reading symbol files or core files). This allows global parameters to
6476 be set, which will apply during the symbol reading. The ./.gdbinit is still
6477 read after argv processing.
6479 * New hosts supported
6481 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6483 GNU/Linux support i386-unknown-linux or linux
6485 We are also including code to support the HP/PA running BSD and HPUX. This
6486 is almost guaranteed not to work, as we didn't have time to test or build it
6487 for this release. We are including it so that the more adventurous (or
6488 masochistic) of you can play with it. We also had major problems with the
6489 fact that the compiler that we got from HP doesn't support the -g option.
6492 * New targets supported
6494 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6496 * More smarts about finding #include files
6498 GDB now remembers the compilation directory for all include files, and for
6499 all files from which C is generated (like yacc and lex sources). This
6500 greatly improves GDB's ability to find yacc/lex sources, and include files,
6501 especially if you are debugging your program from a directory different from
6502 the one that contains your sources.
6504 We also fixed a bug which caused difficulty with listing and setting
6505 breakpoints in include files which contain C code. (In the past, you had to
6506 try twice in order to list an include file that you hadn't looked at before.)
6508 * Interesting infernals change
6510 GDB now deals with arbitrary numbers of sections, where the symbols for each
6511 section must be relocated relative to that section's landing place in the
6512 target's address space. This work was needed to support ELF with embedded
6513 stabs used by Solaris-2.0.
6515 * Bug fixes (of course!)
6517 There have been loads of fixes for the following things:
6518 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6519 i960, stabs, DOS(GO32), procfs, etc...
6521 See the ChangeLog for details.
6523 *** Changes in GDB-4.5:
6525 * New machines supported (host and target)
6527 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6529 SGI Irix-4.x mips-sgi-irix4 or iris4
6531 * New malloc package
6533 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6534 Mmalloc is capable of handling mutiple heaps of memory. It is also
6535 capable of saving a heap to a file, and then mapping it back in later.
6536 This can be used to greatly speedup the startup of GDB by using a
6537 pre-parsed symbol table which lives in a mmalloc managed heap. For
6538 more details, please read mmalloc/mmalloc.texi.
6542 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6543 'help info proc' for details.
6545 * MIPS ecoff symbol table format
6547 The code that reads MIPS symbol table format is now supported on all hosts.
6548 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6551 * File name changes for MS-DOS
6553 Many files in the config directories have been renamed to make it easier to
6554 support GDB on MS-DOSe systems (which have very restrictive file name
6555 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6556 environment) is close to working but has some remaining problems. Note
6557 that debugging of DOS programs is not supported, due to limitations
6558 in the ``operating system'', but it can be used to host cross-debugging.
6560 * Cross byte order fixes
6562 Many fixes have been made to support cross debugging of Sparc and MIPS
6563 targets from hosts whose byte order differs.
6565 * New -mapped and -readnow options
6567 If memory-mapped files are available on your system through the 'mmap'
6568 system call, you can use the -mapped option on the `file' or
6569 `symbol-file' commands to cause GDB to write the symbols from your
6570 program into a reusable file. If the program you are debugging is
6571 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6572 Future GDB debugging sessions will notice the presence of this file,
6573 and will quickly map in symbol information from it, rather than reading
6574 the symbol table from the executable program. Using the '-mapped'
6575 option in a GDB `file' or `symbol-file' command has the same effect as
6576 starting GDB with the '-mapped' command-line option.
6578 You can cause GDB to read the entire symbol table immediately by using
6579 the '-readnow' option with any of the commands that load symbol table
6580 information (or on the GDB command line). This makes the command
6581 slower, but makes future operations faster.
6583 The -mapped and -readnow options are typically combined in order to
6584 build a `fred.syms' file that contains complete symbol information.
6585 A simple GDB invocation to do nothing but build a `.syms' file for future
6588 gdb -batch -nx -mapped -readnow programname
6590 The `.syms' file is specific to the host machine on which GDB is run.
6591 It holds an exact image of GDB's internal symbol table. It cannot be
6592 shared across multiple host platforms.
6594 * longjmp() handling
6596 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6597 siglongjmp() without losing control. This feature has not yet been ported to
6598 all systems. It currently works on many 386 platforms, all MIPS-based
6599 platforms (SGI, DECstation, etc), and Sun3/4.
6603 Preliminary work has been put in to support the new Solaris OS from Sun. At
6604 this time, it can control and debug processes, but it is not capable of
6609 As always, many many bug fixes. The major areas were with g++, and mipsread.
6610 People using the MIPS-based platforms should experience fewer mysterious
6611 crashes and trashed symbol tables.
6613 *** Changes in GDB-4.4:
6615 * New machines supported (host and target)
6617 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6619 BSD Reno on Vax vax-dec-bsd
6620 Ultrix on Vax vax-dec-ultrix
6622 * New machines supported (target)
6624 AMD 29000 embedded, using EBMON a29k-none-none
6628 GDB continues to improve its handling of C++. `References' work better.
6629 The demangler has also been improved, and now deals with symbols mangled as
6630 per the Annotated C++ Reference Guide.
6632 GDB also now handles `stabs' symbol information embedded in MIPS
6633 `ecoff' symbol tables. Since the ecoff format was not easily
6634 extensible to handle new languages such as C++, this appeared to be a
6635 good way to put C++ debugging info into MIPS binaries. This option
6636 will be supported in the GNU C compiler, version 2, when it is
6639 * New features for SVR4
6641 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6642 shared libraries. Debugging dynamically linked programs should present
6643 only minor differences from debugging statically linked programs.
6645 The `info proc' command will print out information about any process
6646 on an SVR4 system (including the one you are debugging). At the moment,
6647 it prints the address mappings of the process.
6649 If you bring up GDB on another SVR4 system, please send mail to
6650 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6652 * Better dynamic linking support in SunOS
6654 Reading symbols from shared libraries which contain debugging symbols
6655 now works properly. However, there remain issues such as automatic
6656 skipping of `transfer vector' code during function calls, which
6657 make it harder to debug code in a shared library, than to debug the
6658 same code linked statically.
6662 GDB is now using the latest `getopt' routines from the FSF. This
6663 version accepts the -- prefix for options with long names. GDB will
6664 continue to accept the old forms (-option and +option) as well.
6665 Various single letter abbreviations for options have been explicity
6666 added to the option table so that they won't get overshadowed in the
6667 future by other options that begin with the same letter.
6671 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6672 Many assorted bugs have been handled. Many more remain to be handled.
6673 See the various ChangeLog files (primarily in gdb and bfd) for details.
6676 *** Changes in GDB-4.3:
6678 * New machines supported (host and target)
6680 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6681 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6682 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6684 * Almost SCO Unix support
6686 We had hoped to support:
6687 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6688 (except for core file support), but we discovered very late in the release
6689 that it has problems with process groups that render gdb unusable. Sorry
6690 about that. I encourage people to fix it and post the fixes.
6692 * Preliminary ELF and DWARF support
6694 GDB can read ELF object files on System V Release 4, and can handle
6695 debugging records for C, in DWARF format, in ELF files. This support
6696 is preliminary. If you bring up GDB on another SVR4 system, please
6697 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6702 GDB now uses the latest `readline' library. One user-visible change
6703 is that two tabs will list possible command completions, which previously
6704 required typing M-? (meta-question mark, or ESC ?).
6708 The `stepi' bug that many of you noticed has been squashed.
6709 Many bugs in C++ have been handled. Many more remain to be handled.
6710 See the various ChangeLog files (primarily in gdb and bfd) for details.
6712 * State of the MIPS world (in case you wondered):
6714 GDB can understand the symbol tables emitted by the compilers
6715 supplied by most vendors of MIPS-based machines, including DEC. These
6716 symbol tables are in a format that essentially nobody else uses.
6718 Some versions of gcc come with an assembler post-processor called
6719 mips-tfile. This program is required if you want to do source-level
6720 debugging of gcc-compiled programs. I believe FSF does not ship
6721 mips-tfile with gcc version 1, but it will eventually come with gcc
6724 Debugging of g++ output remains a problem. g++ version 1.xx does not
6725 really support it at all. (If you're lucky, you should be able to get
6726 line numbers and stack traces to work, but no parameters or local
6727 variables.) With some work it should be possible to improve the
6730 When gcc version 2 is released, you will have somewhat better luck.
6731 However, even then you will get confusing results for inheritance and
6734 We will eventually provide full debugging of g++ output on
6735 DECstations. This will probably involve some kind of stabs-in-ecoff
6736 encapulation, but the details have not been worked out yet.
6739 *** Changes in GDB-4.2:
6741 * Improved configuration
6743 Only one copy of `configure' exists now, and it is not self-modifying.
6744 Porting BFD is simpler.
6748 The `step' and `next' commands now only stop at the first instruction
6749 of a source line. This prevents the multiple stops that used to occur
6750 in switch statements, for-loops, etc. `Step' continues to stop if a
6751 function that has debugging information is called within the line.
6755 Lots of small bugs fixed. More remain.
6757 * New host supported (not target)
6759 Intel 386 PC clone running Mach i386-none-mach
6762 *** Changes in GDB-4.1:
6764 * Multiple source language support
6766 GDB now has internal scaffolding to handle several source languages.
6767 It determines the type of each source file from its filename extension,
6768 and will switch expression parsing and number formatting to match the
6769 language of the function in the currently selected stack frame.
6770 You can also specifically set the language to be used, with
6771 `set language c' or `set language modula-2'.
6775 GDB now has preliminary support for the GNU Modula-2 compiler,
6776 currently under development at the State University of New York at
6777 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6778 continue through the fall of 1991 and into 1992.
6780 Other Modula-2 compilers are currently not supported, and attempting to
6781 debug programs compiled with them will likely result in an error as the
6782 symbol table is read. Feel free to work on it, though!
6784 There are hooks in GDB for strict type checking and range checking,
6785 in the `Modula-2 philosophy', but they do not currently work.
6789 GDB can now write to executable and core files (e.g. patch
6790 a variable's value). You must turn this switch on, specify
6791 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6792 by assigning a new value to a variable. Modifications take
6795 * Automatic SunOS shared library reading
6797 When you run your program, GDB automatically determines where its
6798 shared libraries (if any) have been loaded, and reads their symbols.
6799 The `share' command is no longer needed. This also works when
6800 examining core files.
6804 You can specify the number of lines that the `list' command shows.
6807 * New machines supported (host and target)
6809 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6810 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6811 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6813 * New hosts supported (not targets)
6815 IBM RT/PC: romp-ibm-aix or rtpc
6817 * New targets supported (not hosts)
6819 AMD 29000 embedded with COFF a29k-none-coff
6820 AMD 29000 embedded with a.out a29k-none-aout
6821 Ultracomputer remote kernel debug a29k-nyu-kern
6823 * New remote interfaces
6829 *** Changes in GDB-4.0:
6833 Wide output is wrapped at good places to make the output more readable.
6835 Gdb now supports cross-debugging from a host machine of one type to a
6836 target machine of another type. Communication with the target system
6837 is over serial lines. The ``target'' command handles connecting to the
6838 remote system; the ``load'' command will download a program into the
6839 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6840 also supports debugging of realtime processes running under VxWorks,
6841 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6842 stub on the target system.
6844 New CPUs supported include the AMD 29000 and Intel 960.
6846 GDB now reads object files and symbol tables via a ``binary file''
6847 library, which allows a single copy of GDB to debug programs of multiple
6848 object file types such as a.out and coff.
6850 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6851 refcard.dvi and refcard.ps are available to format it).
6854 * Control-Variable user interface simplified
6856 All variables that control the operation of the debugger can be set
6857 by the ``set'' command, and displayed by the ``show'' command.
6859 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6860 ``Show prompt'' produces the response:
6861 Gdb's prompt is new-gdb=>.
6863 What follows are the NEW set commands. The command ``help set'' will
6864 print a complete list of old and new set commands. ``help set FOO''
6865 will give a longer description of the variable FOO. ``show'' will show
6866 all of the variable descriptions and their current settings.
6868 confirm on/off: Enables warning questions for operations that are
6869 hard to recover from, e.g. rerunning the program while
6870 it is already running. Default is ON.
6872 editing on/off: Enables EMACS style command line editing
6873 of input. Previous lines can be recalled with
6874 control-P, the current line can be edited with control-B,
6875 you can search for commands with control-R, etc.
6878 history filename NAME: NAME is where the gdb command history
6879 will be stored. The default is .gdb_history,
6880 or the value of the environment variable
6883 history size N: The size, in commands, of the command history. The
6884 default is 256, or the value of the environment variable
6887 history save on/off: If this value is set to ON, the history file will
6888 be saved after exiting gdb. If set to OFF, the
6889 file will not be saved. The default is OFF.
6891 history expansion on/off: If this value is set to ON, then csh-like
6892 history expansion will be performed on
6893 command line input. The default is OFF.
6895 radix N: Sets the default radix for input and output. It can be set
6896 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6897 in the current radix, so "set radix 10" is always a no-op.
6899 height N: This integer value is the number of lines on a page. Default
6900 is 24, the current `stty rows'' setting, or the ``li#''
6901 setting from the termcap entry matching the environment
6904 width N: This integer value is the number of characters on a line.
6905 Default is 80, the current `stty cols'' setting, or the ``co#''
6906 setting from the termcap entry matching the environment
6909 Note: ``set screensize'' is obsolete. Use ``set height'' and
6910 ``set width'' instead.
6912 print address on/off: Print memory addresses in various command displays,
6913 such as stack traces and structure values. Gdb looks
6914 more ``symbolic'' if you turn this off; it looks more
6915 ``machine level'' with it on. Default is ON.
6917 print array on/off: Prettyprint arrays. New convenient format! Default
6920 print demangle on/off: Print C++ symbols in "source" form if on,
6923 print asm-demangle on/off: Same, for assembler level printouts
6926 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6929 * Support for Epoch Environment.
6931 The epoch environment is a version of Emacs v18 with windowing. One
6932 new command, ``inspect'', is identical to ``print'', except that if you
6933 are running in the epoch environment, the value is printed in its own
6937 * Support for Shared Libraries
6939 GDB can now debug programs and core files that use SunOS shared libraries.
6940 Symbols from a shared library cannot be referenced
6941 before the shared library has been linked with the program (this
6942 happens after you type ``run'' and before the function main() is entered).
6943 At any time after this linking (including when examining core files
6944 from dynamically linked programs), gdb reads the symbols from each
6945 shared library when you type the ``sharedlibrary'' command.
6946 It can be abbreviated ``share''.
6948 sharedlibrary REGEXP: Load shared object library symbols for files
6949 matching a unix regular expression. No argument
6950 indicates to load symbols for all shared libraries.
6952 info sharedlibrary: Status of loaded shared libraries.
6957 A watchpoint stops execution of a program whenever the value of an
6958 expression changes. Checking for this slows down execution
6959 tremendously whenever you are in the scope of the expression, but is
6960 quite useful for catching tough ``bit-spreader'' or pointer misuse
6961 problems. Some machines such as the 386 have hardware for doing this
6962 more quickly, and future versions of gdb will use this hardware.
6964 watch EXP: Set a watchpoint (breakpoint) for an expression.
6966 info watchpoints: Information about your watchpoints.
6968 delete N: Deletes watchpoint number N (same as breakpoints).
6969 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6970 enable N: Re-enables watchpoint number N (same as breakpoints).
6973 * C++ multiple inheritance
6975 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6978 * C++ exception handling
6980 Gdb now supports limited C++ exception handling. Besides the existing
6981 ability to breakpoint on an exception handler, gdb can breakpoint on
6982 the raising of an exception (before the stack is peeled back to the
6985 catch FOO: If there is a FOO exception handler in the dynamic scope,
6986 set a breakpoint to catch exceptions which may be raised there.
6987 Multiple exceptions (``catch foo bar baz'') may be caught.
6989 info catch: Lists all exceptions which may be caught in the
6990 current stack frame.
6993 * Minor command changes
6995 The command ``call func (arg, arg, ...)'' now acts like the print
6996 command, except it does not print or save a value if the function's result
6997 is void. This is similar to dbx usage.
6999 The ``up'' and ``down'' commands now always print the frame they end up
7000 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7001 frames without printing.
7003 * New directory command
7005 'dir' now adds directories to the FRONT of the source search path.
7006 The path starts off empty. Source files that contain debug information
7007 about the directory in which they were compiled can be found even
7008 with an empty path; Sun CC and GCC include this information. If GDB can't
7009 find your source file in the current directory, type "dir .".
7011 * Configuring GDB for compilation
7013 For normal use, type ``./configure host''. See README or gdb.texinfo
7016 GDB now handles cross debugging. If you are remotely debugging between
7017 two different machines, type ``./configure host -target=targ''.
7018 Host is the machine where GDB will run; targ is the machine
7019 where the program that you are debugging will run.