1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
6 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
7 can be passed using the '[ADDRESS]:PORT' notation, or the regular
10 *** Changes in GDB 8.2
12 * The 'set disassembler-options' command now supports specifying options
15 * The 'symbol-file' command now accepts an '-o' option to add a relative
16 offset to all sections.
18 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
19 a relative offset to all sections, but it allows to override the load
20 address of individual sections using '-s'.
22 * The 'add-symbol-file' command no longer requires the second argument
23 (address of the text section).
25 * The endianness used with the 'set endian auto' mode in the absence of
26 an executable selected for debugging is now the last endianness chosen
27 either by one of the 'set endian big' and 'set endian little' commands
28 or by inferring from the last executable used, rather than the startup
31 * The pager now allows a "c" response, meaning to disable the pager
32 for the rest of the current command.
34 * The commands 'info variables/functions/types' now show the source line
35 numbers of symbol definitions when available.
37 * 'info proc' now works on running processes on FreeBSD systems and core
38 files created on FreeBSD systems.
40 * C expressions can now use _Alignof, and C++ expressions can now use
47 Control display of debugging info regarding the FreeBSD native target.
49 set|show varsize-limit
50 This new setting allows the user to control the maximum size of Ada
51 objects being printed when those objects have a variable type,
52 instead of that maximum size being hardcoded to 65536 bytes.
54 set|show record btrace cpu
55 Controls the processor to be used for enabling errata workarounds for
58 maint check libthread-db
59 Run integrity checks on the current inferior's thread debugging
62 maint set check-libthread-db (on|off)
63 maint show check-libthread-db
64 Control whether to run integrity checks on inferior specific thread
65 debugging libraries as they are loaded. The default is not to
70 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
72 ** The commands attached to a breakpoint can be set by assigning to
73 the breakpoint's "commands" field.
75 ** gdb.execute can now execute multi-line gdb commands.
77 ** The new functions gdb.convenience_variable and
78 gdb.set_convenience_variable can be used to get and set the value
79 of convenience variables.
81 ** A gdb.Parameter will no longer print the "set" help text on an
82 ordinary "set"; instead by default a "set" will be silent unless
83 the get_set_string method returns a non-empty string.
87 RiscV ELF riscv*-*-elf
89 * Removed targets and native configurations
91 m88k running OpenBSD m88*-*-openbsd*
92 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
93 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
94 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
96 * Aarch64/Linux hardware watchpoints improvements
98 Hardware watchpoints on unaligned addresses are now properly
99 supported when running Linux kernel 4.10 or higher: read and access
100 watchpoints are no longer spuriously missed, and all watchpoints
101 lengths between 1 and 8 bytes are supported. On older kernels,
102 watchpoints set on unaligned addresses are no longer missed, with
103 the tradeoff that there is a possibility of false hits being
106 * New configure options
108 --enable-codesign=CERT
109 This can be used to invoke "codesign -s CERT" after building gdb.
110 This option is useful on macOS, where code signing is required for
111 gdb to work properly.
113 *** Changes in GDB 8.1
115 * GDB now supports dynamically creating arbitrary register groups specified
116 in XML target descriptions. This allows for finer grain grouping of
117 registers on systems with a large amount of registers.
119 * The 'ptype' command now accepts a '/o' flag, which prints the
120 offsets and sizes of fields in a struct, like the pahole(1) tool.
122 * New "--readnever" command line option instructs GDB to not read each
123 symbol file's symbolic debug information. This makes startup faster
124 but at the expense of not being able to perform symbolic debugging.
125 This option is intended for use cases where symbolic debugging will
126 not be used, e.g., when you only need to dump the debuggee's core.
128 * GDB now uses the GNU MPFR library, if available, to emulate target
129 floating-point arithmetic during expression evaluation when the target
130 uses different floating-point formats than the host. At least version
131 3.1 of GNU MPFR is required.
133 * GDB now supports access to the guarded-storage-control registers and the
134 software-based guarded-storage broadcast control registers on IBM z14.
136 * On Unix systems, GDB now supports transmitting environment variables
137 that are to be set or unset to GDBserver. These variables will
138 affect the environment to be passed to the remote inferior.
140 To inform GDB of environment variables that are to be transmitted to
141 GDBserver, use the "set environment" command. Only user set
142 environment variables are sent to GDBserver.
144 To inform GDB of environment variables that are to be unset before
145 the remote inferior is started by the GDBserver, use the "unset
146 environment" command.
148 * Completion improvements
150 ** GDB can now complete function parameters in linespecs and
151 explicit locations without quoting. When setting breakpoints,
152 quoting around functions names to help with TAB-completion is
153 generally no longer necessary. For example, this now completes
156 (gdb) b function(in[TAB]
157 (gdb) b function(int)
159 Related, GDB is no longer confused with completing functions in
160 C++ anonymous namespaces:
163 (gdb) b (anonymous namespace)::[TAB][TAB]
164 (anonymous namespace)::a_function()
165 (anonymous namespace)::b_function()
167 ** GDB now has much improved linespec and explicit locations TAB
168 completion support, that better understands what you're
169 completing and offers better suggestions. For example, GDB no
170 longer offers data symbols as possible completions when you're
171 setting a breakpoint.
173 ** GDB now TAB-completes label symbol names.
175 ** The "complete" command now mimics TAB completion accurately.
177 * New command line options (gcore)
180 Dump all memory mappings.
182 * Breakpoints on C++ functions are now set on all scopes by default
184 By default, breakpoints on functions/methods are now interpreted as
185 specifying all functions with the given name ignoring missing
186 leading scopes (namespaces and classes).
188 For example, assuming a C++ program with symbols named:
193 both commands "break func()" and "break B::func()" set a breakpoint
196 You can use the new flag "-qualified" to override this. This makes
197 GDB interpret the specified function name as a complete
198 fully-qualified name instead. For example, using the same C++
199 program, the "break -q B::func" command sets a breakpoint on
200 "B::func", only. A parameter has been added to the Python
201 gdb.Breakpoint constructor to achieve the same result when creating
202 a breakpoint from Python.
204 * Breakpoints on functions marked with C++ ABI tags
206 GDB can now set breakpoints on functions marked with C++ ABI tags
207 (e.g., [abi:cxx11]). See here for a description of ABI tags:
208 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
210 Functions with a C++11 abi tag are demangled/displayed like this:
212 function[abi:cxx11](int)
215 You can now set a breakpoint on such functions simply as if they had
218 (gdb) b function(int)
220 Or if you need to disambiguate between tags, like:
222 (gdb) b function[abi:other_tag](int)
224 Tab completion was adjusted accordingly as well.
228 ** New events gdb.new_inferior, gdb.inferior_deleted, and
229 gdb.new_thread are emitted. See the manual for further
230 description of these.
232 ** A new function, "gdb.rbreak" has been added to the Python API.
233 This function allows the setting of a large number of breakpoints
234 via a regex pattern in Python. See the manual for further details.
236 ** Python breakpoints can now accept explicit locations. See the
237 manual for a further description of this feature.
240 * New features in the GDB remote stub, GDBserver
242 ** GDBserver is now able to start inferior processes with a
243 specified initial working directory.
245 The user can set the desired working directory to be used from
246 GDB using the new "set cwd" command.
248 ** New "--selftest" command line option runs some GDBserver self
249 tests. These self tests are disabled in releases.
251 ** On Unix systems, GDBserver now does globbing expansion and variable
252 substitution in inferior command line arguments.
254 This is done by starting inferiors using a shell, like GDB does.
255 See "set startup-with-shell" in the user manual for how to disable
256 this from GDB when using "target extended-remote". When using
257 "target remote", you can disable the startup with shell by using the
258 new "--no-startup-with-shell" GDBserver command line option.
260 ** On Unix systems, GDBserver now supports receiving environment
261 variables that are to be set or unset from GDB. These variables
262 will affect the environment to be passed to the inferior.
264 * When catching an Ada exception raised with a message, GDB now prints
265 the message in the catchpoint hit notification. In GDB/MI mode, that
266 information is provided as an extra field named "exception-message"
267 in the *stopped notification.
269 * Trait objects can now be inspected When debugging Rust code. This
270 requires compiler support which will appear in Rust 1.24.
274 QEnvironmentHexEncoded
275 Inform GDBserver of an environment variable that is to be passed to
276 the inferior when starting it.
279 Inform GDBserver of an environment variable that is to be unset
280 before starting the remote inferior.
283 Inform GDBserver that the environment should be reset (i.e.,
284 user-set environment variables should be unset).
287 Indicates whether the inferior must be started with a shell or not.
290 Tell GDBserver that the inferior to be started should use a specific
293 * The "maintenance print c-tdesc" command now takes an optional
294 argument which is the file name of XML target description.
296 * The "maintenance selftest" command now takes an optional argument to
297 filter the tests to be run.
299 * The "enable", and "disable" commands now accept a range of
300 breakpoint locations, e.g. "enable 1.3-5".
305 Set and show the current working directory for the inferior.
308 Set and show compilation command used for compiling and injecting code
309 with the 'compile' commands.
311 set debug separate-debug-file
312 show debug separate-debug-file
313 Control the display of debug output about separate debug file search.
315 set dump-excluded-mappings
316 show dump-excluded-mappings
317 Control whether mappings marked with the VM_DONTDUMP flag should be
318 dumped when generating a core file.
321 List the registered selftests.
324 Start the debugged program stopping at the first instruction.
327 Control display of debugging messages related to OpenRISC targets.
329 set|show print type nested-type-limit
330 Set and show the limit of nesting level for nested types that the
331 type printer will show.
333 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
336 * Safer/improved support for debugging with no debug info
338 GDB no longer assumes functions with no debug information return
341 This means that GDB now refuses to call such functions unless you
342 tell it the function's type, by either casting the call to the
343 declared return type, or by casting the function to a function
344 pointer of the right type, and calling that:
346 (gdb) p getenv ("PATH")
347 'getenv' has unknown return type; cast the call to its declared return type
348 (gdb) p (char *) getenv ("PATH")
349 $1 = 0x7fffffffe "/usr/local/bin:/"...
350 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
351 $2 = 0x7fffffffe "/usr/local/bin:/"...
353 Similarly, GDB no longer assumes that global variables with no debug
354 info have type 'int', and refuses to print the variable's value
355 unless you tell it the variable's type:
358 'var' has unknown type; cast it to its declared type
362 * New native configurations
364 FreeBSD/aarch64 aarch64*-*-freebsd*
365 FreeBSD/arm arm*-*-freebsd*
369 FreeBSD/aarch64 aarch64*-*-freebsd*
370 FreeBSD/arm arm*-*-freebsd*
371 OpenRISC ELF or1k*-*-elf
373 * Removed targets and native configurations
375 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
377 *** Changes in GDB 8.0
379 * GDB now supports access to the PKU register on GNU/Linux. The register is
380 added by the Memory Protection Keys for Userspace feature which will be
381 available in future Intel CPUs.
383 * GDB now supports C++11 rvalue references.
387 ** New functions to start, stop and access a running btrace recording.
388 ** Rvalue references are now supported in gdb.Type.
390 * GDB now supports recording and replaying rdrand and rdseed Intel 64
393 * Building GDB and GDBserver now requires a C++11 compiler.
395 For example, GCC 4.8 or later.
397 It is no longer possible to build GDB or GDBserver with a C
398 compiler. The --disable-build-with-cxx configure option has been
401 * Building GDB and GDBserver now requires GNU make >= 3.81.
403 It is no longer supported to build GDB or GDBserver with another
404 implementation of the make program or an earlier version of GNU make.
406 * Native debugging on MS-Windows supports command-line redirection
408 Command-line arguments used for starting programs on MS-Windows can
409 now include redirection symbols supported by native Windows shells,
410 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
411 as "run", "start", and "set args", as well as the corresponding MI
414 * Support for thread names on MS-Windows.
416 GDB now catches and handles the special exception that programs
417 running on MS-Windows use to assign names to threads in the
420 * Support for Java programs compiled with gcj has been removed.
422 * User commands now accept an unlimited number of arguments.
423 Previously, only up to 10 was accepted.
425 * The "eval" command now expands user-defined command arguments.
427 This makes it easier to process a variable number of arguments:
432 eval "print $arg%d", $i
437 * Target descriptions can now describe registers for sparc32 and sparc64.
439 * GDB now supports DWARF version 5 (debug information format).
440 Its .debug_names index is not yet supported.
442 * New native configurations
444 FreeBSD/mips mips*-*-freebsd
448 Synopsys ARC arc*-*-elf32
449 FreeBSD/mips mips*-*-freebsd
451 * Removed targets and native configurations
453 Alpha running FreeBSD alpha*-*-freebsd*
454 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
459 Erases all the flash memory regions reported by the target.
461 maint print arc arc-instruction address
462 Print internal disassembler information about instruction at a given address.
466 set disassembler-options
467 show disassembler-options
468 Controls the passing of target specific information to the disassembler.
469 If it is necessary to specify more than one disassembler option then
470 multiple options can be placed together into a comma separated list.
471 The default value is the empty string. Currently, the only supported
472 targets are ARM, PowerPC and S/390.
477 Erases all the flash memory regions reported by the target. This is
478 equivalent to the CLI command flash-erase.
480 -file-list-shared-libraries
481 List the shared libraries in the program. This is
482 equivalent to the CLI command "info shared".
485 Catchpoints stopping the program when Ada exceptions are
486 handled. This is equivalent to the CLI command "catch handlers".
488 *** Changes in GDB 7.12
490 * GDB and GDBserver now build with a C++ compiler by default.
492 The --enable-build-with-cxx configure option is now enabled by
493 default. One must now explicitly configure with
494 --disable-build-with-cxx in order to build with a C compiler. This
495 option will be removed in a future release.
497 * GDBserver now supports recording btrace without maintaining an active
500 * GDB now supports a negative repeat count in the 'x' command to examine
501 memory backward from the given address. For example:
504 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
505 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
506 (gdb) x/-5i 0x0000000000400580
507 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
508 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
509 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
510 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
511 0x40057b <main(int, char**)+25>:
512 callq 0x400536 <Func1(int, char const*)>
514 * Fortran: Support structures with fields of dynamic types and
515 arrays of dynamic types.
517 * The symbol dumping maintenance commands have new syntax.
518 maint print symbols [-pc address] [--] [filename]
519 maint print symbols [-objfile objfile] [-source source] [--] [filename]
520 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
521 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
522 maint print msymbols [-objfile objfile] [--] [filename]
524 * GDB now supports multibit bitfields and enums in target register
527 * New Python-based convenience function $_as_string(val), which returns
528 the textual representation of a value. This function is especially
529 useful to obtain the text label of an enum value.
531 * Intel MPX bound violation handling.
533 Segmentation faults caused by a Intel MPX boundary violation
534 now display the kind of violation (upper or lower), the memory
535 address accessed and the memory bounds, along with the usual
536 signal received and code location.
540 Program received signal SIGSEGV, Segmentation fault
541 Upper bound violation while accessing address 0x7fffffffc3b3
542 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
543 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
545 * Rust language support.
546 GDB now supports debugging programs written in the Rust programming
547 language. See https://www.rust-lang.org/ for more information about
550 * Support for running interpreters on specified input/output devices
552 GDB now supports a new mechanism that allows frontends to provide
553 fully featured GDB console views, as a better alternative to
554 building such views on top of the "-interpreter-exec console"
555 command. See the new "new-ui" command below. With that command,
556 frontends can now start GDB in the traditional command-line mode
557 running in an embedded terminal emulator widget, and create a
558 separate MI interpreter running on a specified i/o device. In this
559 way, GDB handles line editing, history, tab completion, etc. in the
560 console all by itself, and the GUI uses the separate MI interpreter
561 for its own control and synchronization, invisible to the command
564 * The "catch syscall" command catches groups of related syscalls.
566 The "catch syscall" command now supports catching a group of related
567 syscalls using the 'group:' or 'g:' prefix.
572 skip -gfile file-glob-pattern
573 skip -function function
574 skip -rfunction regular-expression
575 A generalized form of the skip command, with new support for
576 glob-style file names and regular expressions for function names.
577 Additionally, a file spec and a function spec may now be combined.
579 maint info line-table REGEXP
580 Display the contents of GDB's internal line table data struture.
583 Run any GDB unit tests that were compiled in.
586 Start a new user interface instance running INTERP as interpreter,
587 using the TTY file for input/output.
591 ** gdb.Breakpoint objects have a new attribute "pending", which
592 indicates whether the breakpoint is pending.
593 ** Three new breakpoint-related events have been added:
594 gdb.breakpoint_created, gdb.breakpoint_modified, and
595 gdb.breakpoint_deleted.
598 Signal ("set") the given MS-Windows event object. This is used in
599 conjunction with the Windows JIT debugging (AeDebug) support, where
600 the OS suspends a crashing process until a debugger can attach to
601 it. Resuming the crashing process, in order to debug it, is done by
604 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
605 was added in GDBserver, including JIT compiling fast tracepoint's
606 conditional expression bytecode into native code.
608 * Support for various remote target protocols and ROM monitors has
611 target m32rsdi Remote M32R debugging over SDI
612 target mips MIPS remote debugging protocol
613 target pmon PMON ROM monitor
614 target ddb NEC's DDB variant of PMON for Vr4300
615 target rockhopper NEC RockHopper variant of PMON
616 target lsi LSI variant of PMO
618 * Support for tracepoints and fast tracepoints on powerpc-linux,
619 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
620 including JIT compiling fast tracepoint's conditional expression
621 bytecode into native code.
623 * MI async record =record-started now includes the method and format used for
624 recording. For example:
626 =record-started,thread-group="i1",method="btrace",format="bts"
628 * MI async record =thread-selected now includes the frame field. For example:
630 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
634 Andes NDS32 nds32*-*-elf
636 *** Changes in GDB 7.11
638 * GDB now supports debugging kernel-based threads on FreeBSD.
640 * Per-inferior thread numbers
642 Thread numbers are now per inferior instead of global. If you're
643 debugging multiple inferiors, GDB displays thread IDs using a
644 qualified INF_NUM.THR_NUM form. For example:
648 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
649 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
650 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
651 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
653 As consequence, thread numbers as visible in the $_thread
654 convenience variable and in Python's InferiorThread.num attribute
655 are no longer unique between inferiors.
657 GDB now maintains a second thread ID per thread, referred to as the
658 global thread ID, which is the new equivalent of thread numbers in
659 previous releases. See also $_gthread below.
661 For backwards compatibility, MI's thread IDs always refer to global
664 * Commands that accept thread IDs now accept the qualified
665 INF_NUM.THR_NUM form as well. For example:
668 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
671 * In commands that accept a list of thread IDs, you can now refer to
672 all threads of an inferior using a star wildcard. GDB accepts
673 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
674 refer to all threads of the current inferior. For example, "info
677 * You can use "info threads -gid" to display the global thread ID of
680 * The new convenience variable $_gthread holds the global number of
683 * The new convenience variable $_inferior holds the number of the
686 * GDB now displays the ID and name of the thread that hit a breakpoint
687 or received a signal, if your program is multi-threaded. For
690 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
691 Thread 1 "main" received signal SIGINT, Interrupt.
693 * Record btrace now supports non-stop mode.
695 * Support for tracepoints on aarch64-linux was added in GDBserver.
697 * The 'record instruction-history' command now indicates speculative execution
698 when using the Intel Processor Trace recording format.
700 * GDB now allows users to specify explicit locations, bypassing
701 the linespec parser. This feature is also available to GDB/MI
704 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
705 GDB now is able to debug both AArch64 applications and ARM applications
708 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
709 including JIT compiling fast tracepoint's conditional expression bytecode
712 * GDB now supports displaced stepping on AArch64 GNU/Linux.
714 * "info threads", "info inferiors", "info display", "info checkpoints"
715 and "maint info program-spaces" now list the corresponding items in
716 ascending ID order, for consistency with all other "info" commands.
718 * In Ada, the overloads selection menu has been enhanced to display the
719 parameter types and the return types for the matching overloaded subprograms.
723 maint set target-non-stop (on|off|auto)
724 maint show target-non-stop
725 Control whether GDB targets always operate in non-stop mode even if
726 "set non-stop" is "off". The default is "auto", meaning non-stop
727 mode is enabled if supported by the target.
729 maint set bfd-sharing
730 maint show bfd-sharing
731 Control the reuse of bfd objects.
735 Control display of debugging info regarding bfd caching.
739 Control display of debugging info regarding FreeBSD threads.
741 set remote multiprocess-extensions-packet
742 show remote multiprocess-extensions-packet
743 Set/show the use of the remote protocol multiprocess extensions.
745 set remote thread-events
746 show remote thread-events
747 Set/show the use of thread create/exit events.
749 set ada print-signatures on|off
750 show ada print-signatures"
751 Control whether parameter types and return types are displayed in overloads
752 selection menus. It is activaled (@code{on}) by default.
756 Controls the maximum size of memory, in bytes, that GDB will
757 allocate for value contents. Prevents incorrect programs from
758 causing GDB to allocate overly large buffers. Default is 64k.
760 * The "disassemble" command accepts a new modifier: /s.
761 It prints mixed source+disassembly like /m with two differences:
762 - disassembled instructions are now printed in program order, and
763 - and source for all relevant files is now printed.
764 The "/m" option is now considered deprecated: its "source-centric"
765 output hasn't proved useful in practice.
767 * The "record instruction-history" command accepts a new modifier: /s.
768 It behaves exactly like /m and prints mixed source+disassembly.
770 * The "set scheduler-locking" command supports a new mode "replay".
771 It behaves like "off" in record mode and like "on" in replay mode.
773 * Support for various ROM monitors has been removed:
775 target dbug dBUG ROM monitor for Motorola ColdFire
776 target picobug Motorola picobug monitor
777 target dink32 DINK32 ROM monitor for PowerPC
778 target m32r Renesas M32R/D ROM monitor
779 target mon2000 mon2000 ROM monitor
780 target ppcbug PPCBUG ROM monitor for PowerPC
782 * Support for reading/writing memory and extracting values on architectures
783 whose memory is addressable in units of any integral multiple of 8 bits.
786 Allows to break when an Ada exception is handled.
791 Indicates that an exec system call was executed.
793 exec-events feature in qSupported
794 The qSupported packet allows GDB to request support for exec
795 events using the new 'gdbfeature' exec-event, and the qSupported
796 response can contain the corresponding 'stubfeature'. Set and
797 show commands can be used to display whether these features are enabled.
800 Equivalent to interrupting with the ^C character, but works in
803 thread created stop reason (T05 create:...)
804 Indicates that the thread was just created and is stopped at entry.
806 thread exit stop reply (w exitcode;tid)
807 Indicates that the thread has terminated.
810 Enables/disables thread create and exit event reporting. For
811 example, this is used in non-stop mode when GDB stops a set of
812 threads and synchronously waits for the their corresponding stop
813 replies. Without exit events, if one of the threads exits, GDB
814 would hang forever not knowing that it should no longer expect a
815 stop for that same thread.
818 Indicates that there are no resumed threads left in the target (all
819 threads are stopped). The remote stub reports support for this stop
820 reply to GDB's qSupported query.
823 Enables/disables catching syscalls from the inferior process.
824 The remote stub reports support for this packet to GDB's qSupported query.
826 syscall_entry stop reason
827 Indicates that a syscall was just called.
829 syscall_return stop reason
830 Indicates that a syscall just returned.
832 * Extended-remote exec events
834 ** GDB now has support for exec events on extended-remote Linux targets.
835 For such targets with Linux kernels 2.5.46 and later, this enables
836 follow-exec-mode and exec catchpoints.
838 set remote exec-event-feature-packet
839 show remote exec-event-feature-packet
840 Set/show the use of the remote exec event feature.
842 * Thread names in remote protocol
844 The reply to qXfer:threads:read may now include a name attribute for each
847 * Target remote mode fork and exec events
849 ** GDB now has support for fork and exec events on target remote mode
850 Linux targets. For such targets with Linux kernels 2.5.46 and later,
851 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
852 fork and exec catchpoints.
854 * Remote syscall events
856 ** GDB now has support for catch syscall on remote Linux targets,
857 currently enabled on x86/x86_64 architectures.
859 set remote catch-syscall-packet
860 show remote catch-syscall-packet
861 Set/show the use of the remote catch syscall feature.
865 ** The -var-set-format command now accepts the zero-hexadecimal
866 format. It outputs data in hexadecimal format with zero-padding on the
871 ** gdb.InferiorThread objects have a new attribute "global_num",
872 which refers to the thread's global thread ID. The existing
873 "num" attribute now refers to the thread's per-inferior number.
874 See "Per-inferior thread numbers" above.
875 ** gdb.InferiorThread objects have a new attribute "inferior", which
876 is the Inferior object the thread belongs to.
878 *** Changes in GDB 7.10
880 * Support for process record-replay and reverse debugging on aarch64*-linux*
881 targets has been added. GDB now supports recording of A64 instruction set
882 including advance SIMD instructions.
884 * Support for Sun's version of the "stabs" debug file format has been removed.
886 * GDB now honors the content of the file /proc/PID/coredump_filter
887 (PID is the process ID) on GNU/Linux systems. This file can be used
888 to specify the types of memory mappings that will be included in a
889 corefile. For more information, please refer to the manual page of
890 "core(5)". GDB also has a new command: "set use-coredump-filter
891 on|off". It allows to set whether GDB will read the content of the
892 /proc/PID/coredump_filter file when generating a corefile.
894 * The "info os" command on GNU/Linux can now display information on
896 "info os cpus" Listing of all cpus/cores on the system
898 * GDB has two new commands: "set serial parity odd|even|none" and
899 "show serial parity". These allows to set or show parity for the
902 * The "info source" command now displays the producer string if it was
903 present in the debug info. This typically includes the compiler version
904 and may include things like its command line arguments.
906 * The "info dll", an alias of the "info sharedlibrary" command,
907 is now available on all platforms.
909 * Directory names supplied to the "set sysroot" commands may be
910 prefixed with "target:" to tell GDB to access shared libraries from
911 the target system, be it local or remote. This replaces the prefix
912 "remote:". The default sysroot has been changed from "" to
913 "target:". "remote:" is automatically converted to "target:" for
914 backward compatibility.
916 * The system root specified by "set sysroot" will be prepended to the
917 filename of the main executable (if reported to GDB as absolute by
918 the operating system) when starting processes remotely, and when
919 attaching to already-running local or remote processes.
921 * GDB now supports automatic location and retrieval of executable
922 files from remote targets. Remote debugging can now be initiated
923 using only a "target remote" or "target extended-remote" command
924 (no "set sysroot" or "file" commands are required). See "New remote
927 * The "dump" command now supports verilog hex format.
929 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
931 * On GNU/Linux, GDB and gdbserver are now able to access executable
932 and shared library files without a "set sysroot" command when
933 attaching to processes running in different mount namespaces from
934 the debugger. This makes it possible to attach to processes in
935 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
936 See "New remote packets" below.
938 * The "tui reg" command now provides completion for all of the
939 available register groups, including target specific groups.
941 * The HISTSIZE environment variable is no longer read when determining
942 the size of GDB's command history. GDB now instead reads the dedicated
943 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
944 disables truncation of command history. Non-numeric values of GDBHISTSIZE
949 ** Memory ports can now be unbuffered.
953 ** gdb.Objfile objects have a new attribute "username",
954 which is the name of the objfile as specified by the user,
955 without, for example, resolving symlinks.
956 ** You can now write frame unwinders in Python.
957 ** gdb.Type objects have a new method "optimized_out",
958 returning optimized out gdb.Value instance of this type.
959 ** gdb.Value objects have new methods "reference_value" and
960 "const_value" which return a reference to the value and a
961 "const" version of the value respectively.
965 maint print symbol-cache
966 Print the contents of the symbol cache.
968 maint print symbol-cache-statistics
969 Print statistics of symbol cache usage.
971 maint flush-symbol-cache
972 Flush the contents of the symbol cache.
976 Start branch trace recording using Branch Trace Store (BTS) format.
979 Evaluate expression by using the compiler and print result.
983 Explicit commands for enabling and disabling tui mode.
986 set mpx bound on i386 and amd64
987 Support for bound table investigation on Intel MPX enabled applications.
991 Start branch trace recording using Intel Processor Trace format.
994 Print information about branch tracing internals.
996 maint btrace packet-history
997 Print the raw branch tracing data.
999 maint btrace clear-packet-history
1000 Discard the stored raw branch tracing data.
1003 Discard all branch tracing data. It will be fetched and processed
1004 anew by the next "record" command.
1009 Renamed from "set debug dwarf2-die".
1010 show debug dwarf-die
1011 Renamed from "show debug dwarf2-die".
1013 set debug dwarf-read
1014 Renamed from "set debug dwarf2-read".
1015 show debug dwarf-read
1016 Renamed from "show debug dwarf2-read".
1018 maint set dwarf always-disassemble
1019 Renamed from "maint set dwarf2 always-disassemble".
1020 maint show dwarf always-disassemble
1021 Renamed from "maint show dwarf2 always-disassemble".
1023 maint set dwarf max-cache-age
1024 Renamed from "maint set dwarf2 max-cache-age".
1025 maint show dwarf max-cache-age
1026 Renamed from "maint show dwarf2 max-cache-age".
1028 set debug dwarf-line
1029 show debug dwarf-line
1030 Control display of debugging info regarding DWARF line processing.
1033 show max-completions
1034 Set the maximum number of candidates to be considered during
1035 completion. The default value is 200. This limit allows GDB
1036 to avoid generating large completion lists, the computation of
1037 which can cause the debugger to become temporarily unresponsive.
1039 set history remove-duplicates
1040 show history remove-duplicates
1041 Control the removal of duplicate history entries.
1043 maint set symbol-cache-size
1044 maint show symbol-cache-size
1045 Control the size of the symbol cache.
1047 set|show record btrace bts buffer-size
1048 Set and show the size of the ring buffer used for branch tracing in
1050 The obtained size may differ from the requested size. Use "info
1051 record" to see the obtained buffer size.
1053 set debug linux-namespaces
1054 show debug linux-namespaces
1055 Control display of debugging info regarding Linux namespaces.
1057 set|show record btrace pt buffer-size
1058 Set and show the size of the ring buffer used for branch tracing in
1059 Intel Processor Trace format.
1060 The obtained size may differ from the requested size. Use "info
1061 record" to see the obtained buffer size.
1063 maint set|show btrace pt skip-pad
1064 Set and show whether PAD packets are skipped when computing the
1067 * The command 'thread apply all' can now support new option '-ascending'
1068 to call its specified command for all threads in ascending order.
1070 * Python/Guile scripting
1072 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1073 special section named `.debug_gdb_scripts'.
1075 * New remote packets
1077 qXfer:btrace-conf:read
1078 Return the branch trace configuration for the current thread.
1080 Qbtrace-conf:bts:size
1081 Set the requested ring buffer size for branch tracing in BTS format.
1084 Enable Intel Procesor Trace-based branch tracing for the current
1085 process. The remote stub reports support for this packet to GDB's
1088 Qbtrace-conf:pt:size
1089 Set the requested ring buffer size for branch tracing in Intel Processor
1093 Indicates a memory breakpoint instruction was executed, irrespective
1094 of whether it was GDB that planted the breakpoint or the breakpoint
1095 is hardcoded in the program. This is required for correct non-stop
1099 Indicates the target stopped for a hardware breakpoint. This is
1100 required for correct non-stop mode operation.
1103 Return information about files on the remote system.
1105 qXfer:exec-file:read
1106 Return the full absolute name of the file that was executed to
1107 create a process running on the remote system.
1110 Select the filesystem on which vFile: operations with filename
1111 arguments will operate. This is required for GDB to be able to
1112 access files on remote targets where the remote stub does not
1113 share a common filesystem with the inferior(s).
1116 Indicates that a fork system call was executed.
1119 Indicates that a vfork system call was executed.
1121 vforkdone stop reason
1122 Indicates that a vfork child of the specified process has executed
1123 an exec or exit, allowing the vfork parent to resume execution.
1125 fork-events and vfork-events features in qSupported
1126 The qSupported packet allows GDB to request support for fork and
1127 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1128 and the qSupported response can contain the corresponding
1129 'stubfeatures'. Set and show commands can be used to display
1130 whether these features are enabled.
1132 * Extended-remote fork events
1134 ** GDB now has support for fork events on extended-remote Linux
1135 targets. For targets with Linux kernels 2.5.60 and later, this
1136 enables follow-fork-mode and detach-on-fork for both fork and
1137 vfork, as well as fork and vfork catchpoints.
1139 * The info record command now shows the recording format and the
1140 branch tracing configuration for the current thread when using
1141 the btrace record target.
1142 For the BTS format, it shows the ring buffer size.
1144 * GDB now has support for DTrace USDT (Userland Static Defined
1145 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1147 * GDB now supports access to vector registers on S/390 GNU/Linux
1150 * Removed command line options
1152 -xdb HP-UX XDB compatibility mode.
1154 * Removed targets and native configurations
1156 HP/PA running HP-UX hppa*-*-hpux*
1157 Itanium running HP-UX ia64-*-hpux*
1159 * New configure options
1162 This configure option allows the user to build GDB with support for
1163 Intel Processor Trace (default: auto). This requires libipt.
1165 --with-libipt-prefix=PATH
1166 Specify the path to the version of libipt that GDB should use.
1167 $PATH/include should contain the intel-pt.h header and
1168 $PATH/lib should contain the libipt.so library.
1170 *** Changes in GDB 7.9.1
1174 ** Xmethods can now specify a result type.
1176 *** Changes in GDB 7.9
1178 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1182 ** You can now access frame registers from Python scripts.
1183 ** New attribute 'producer' for gdb.Symtab objects.
1184 ** gdb.Objfile objects have a new attribute "progspace",
1185 which is the gdb.Progspace object of the containing program space.
1186 ** gdb.Objfile objects have a new attribute "owner".
1187 ** gdb.Objfile objects have a new attribute "build_id",
1188 which is the build ID generated when the file was built.
1189 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1190 ** A new event "gdb.clear_objfiles" has been added, triggered when
1191 selecting a new file to debug.
1192 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1193 ** New function gdb.lookup_objfile.
1195 New events which are triggered when GDB modifies the state of the
1198 ** gdb.events.inferior_call_pre: Function call is about to be made.
1199 ** gdb.events.inferior_call_post: Function call has just been made.
1200 ** gdb.events.memory_changed: A memory location has been altered.
1201 ** gdb.events.register_changed: A register has been altered.
1203 * New Python-based convenience functions:
1205 ** $_caller_is(name [, number_of_frames])
1206 ** $_caller_matches(regexp [, number_of_frames])
1207 ** $_any_caller_is(name [, number_of_frames])
1208 ** $_any_caller_matches(regexp [, number_of_frames])
1210 * GDB now supports the compilation and injection of source code into
1211 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1212 to compile the source code to object code, and if successful, inject
1213 and execute that code within the current context of the inferior.
1214 Currently the C language is supported. The commands used to
1215 interface with this new feature are:
1217 compile code [-raw|-r] [--] [source code]
1218 compile file [-raw|-r] filename
1222 demangle [-l language] [--] name
1223 Demangle "name" in the specified language, or the current language
1224 if elided. This command is renamed from the "maint demangle" command.
1225 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1226 as "maint demangler-warning".
1228 queue-signal signal-name-or-number
1229 Queue a signal to be delivered to the thread when it is resumed.
1231 add-auto-load-scripts-directory directory
1232 Add entries to the list of directories from which to load auto-loaded
1235 maint print user-registers
1236 List all currently available "user" registers.
1238 compile code [-r|-raw] [--] [source code]
1239 Compile, inject, and execute in the inferior the executable object
1240 code produced by compiling the provided source code.
1242 compile file [-r|-raw] filename
1243 Compile and inject into the inferior the executable object code
1244 produced by compiling the source code stored in the filename
1247 * On resume, GDB now always passes the signal the program had stopped
1248 for to the thread the signal was sent to, even if the user changed
1249 threads before resuming. Previously GDB would often (but not
1250 always) deliver the signal to the thread that happens to be current
1253 * Conversely, the "signal" command now consistently delivers the
1254 requested signal to the current thread. GDB now asks for
1255 confirmation if the program had stopped for a signal and the user
1256 switched threads meanwhile.
1258 * "breakpoint always-inserted" modes "off" and "auto" merged.
1260 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1261 won't remove breakpoints from the target until all threads stop,
1262 even in non-stop mode. The "auto" mode has been removed, and "off"
1263 is now the default mode.
1267 set debug symbol-lookup
1268 show debug symbol-lookup
1269 Control display of debugging info regarding symbol lookup.
1273 ** The -list-thread-groups command outputs an exit-code field for
1274 inferiors that have exited.
1278 MIPS SDE mips*-sde*-elf*
1282 Support for these obsolete configurations has been removed.
1284 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1285 SGI Irix-5.x mips-*-irix5*
1286 SGI Irix-6.x mips-*-irix6*
1287 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1288 VAX running Ultrix vax-*-ultrix*
1290 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1291 and "assf"), have been removed. Use the "sharedlibrary" command, or
1292 its alias "share", instead.
1294 *** Changes in GDB 7.8
1296 * New command line options
1299 This is an alias for the --data-directory option.
1301 * GDB supports printing and modifying of variable length automatic arrays
1302 as specified in ISO C99.
1304 * The ARM simulator now supports instruction level tracing
1305 with or without disassembly.
1309 GDB now has support for scripting using Guile. Whether this is
1310 available is determined at configure time.
1311 Guile version 2.0 or greater is required.
1312 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1314 * New commands (for set/show, see "New options" below)
1318 Invoke CODE by passing it to the Guile interpreter.
1322 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1324 info auto-load guile-scripts [regexp]
1325 Print the list of automatically loaded Guile scripts.
1327 * The source command is now capable of sourcing Guile scripts.
1328 This feature is dependent on the debugger being built with Guile support.
1332 set print symbol-loading (off|brief|full)
1333 show print symbol-loading
1334 Control whether to print informational messages when loading symbol
1335 information for a file. The default is "full", but when debugging
1336 programs with large numbers of shared libraries the amount of output
1337 becomes less useful.
1339 set guile print-stack (none|message|full)
1340 show guile print-stack
1341 Show a stack trace when an error is encountered in a Guile script.
1343 set auto-load guile-scripts (on|off)
1344 show auto-load guile-scripts
1345 Control auto-loading of Guile script files.
1347 maint ada set ignore-descriptive-types (on|off)
1348 maint ada show ignore-descriptive-types
1349 Control whether the debugger should ignore descriptive types in Ada
1350 programs. The default is not to ignore the descriptive types. See
1351 the user manual for more details on descriptive types and the intended
1352 usage of this option.
1354 set auto-connect-native-target
1356 Control whether GDB is allowed to automatically connect to the
1357 native target for the run, attach, etc. commands when not connected
1358 to any target yet. See also "target native" below.
1360 set record btrace replay-memory-access (read-only|read-write)
1361 show record btrace replay-memory-access
1362 Control what memory accesses are allowed during replay.
1364 maint set target-async (on|off)
1365 maint show target-async
1366 This controls whether GDB targets operate in synchronous or
1367 asynchronous mode. Normally the default is asynchronous, if it is
1368 available; but this can be changed to more easily debug problems
1369 occurring only in synchronous mode.
1371 set mi-async (on|off)
1373 Control whether MI asynchronous mode is preferred. This supersedes
1374 "set target-async" of previous GDB versions.
1376 * "set target-async" is deprecated as a CLI option and is now an alias
1377 for "set mi-async" (only puts MI into async mode).
1379 * Background execution commands (e.g., "c&", "s&", etc.) are now
1380 possible ``out of the box'' if the target supports them. Previously
1381 the user would need to explicitly enable the possibility with the
1382 "set target-async on" command.
1384 * New features in the GDB remote stub, GDBserver
1386 ** New option --debug-format=option1[,option2,...] allows one to add
1387 additional text to each output. At present only timestamps
1388 are supported: --debug-format=timestamps.
1389 Timestamps can also be turned on with the
1390 "monitor set debug-format timestamps" command from GDB.
1392 * The 'record instruction-history' command now starts counting instructions
1393 at one. This also affects the instruction ranges reported by the
1394 'record function-call-history' command when given the /i modifier.
1396 * The command 'record function-call-history' supports a new modifier '/c' to
1397 indent the function names based on their call stack depth.
1398 The fields for the '/i' and '/l' modifier have been reordered.
1399 The source line range is now prefixed with 'at'.
1400 The instruction range is now prefixed with 'inst'.
1401 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1402 "record instruction-history" and "list" commands.
1404 * The ranges given as arguments to the 'record function-call-history' and
1405 'record instruction-history' commands are now inclusive.
1407 * The btrace record target now supports the 'record goto' command.
1408 For locations inside the execution trace, the back trace is computed
1409 based on the information stored in the execution trace.
1411 * The btrace record target supports limited reverse execution and replay.
1412 The target does not record data and therefore does not allow reading
1413 memory or registers.
1415 * The "catch syscall" command now works on s390*-linux* targets.
1417 * The "compare-sections" command is no longer specific to target
1418 remote. It now works with all targets.
1420 * All native targets are now consistently called "native".
1421 Consequently, the "target child", "target GNU", "target djgpp",
1422 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1423 commands have been replaced with "target native". The QNX/NTO port
1424 leaves the "procfs" target in place and adds a "native" target for
1425 consistency with other ports. The impact on users should be minimal
1426 as these commands previously either throwed an error, or were
1427 no-ops. The target's name is visible in the output of the following
1428 commands: "help target", "info target", "info files", "maint print
1431 * The "target native" command now connects to the native target. This
1432 can be used to launch native programs even when "set
1433 auto-connect-native-target" is set to off.
1435 * GDB now supports access to Intel MPX registers on GNU/Linux.
1437 * Support for Intel AVX-512 registers on GNU/Linux.
1438 Support displaying and modifying Intel AVX-512 registers
1439 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1441 * New remote packets
1443 qXfer:btrace:read's annex
1444 The qXfer:btrace:read packet supports a new annex 'delta' to read
1445 branch trace incrementally.
1449 ** Valid Python operations on gdb.Value objects representing
1450 structs/classes invoke the corresponding overloaded operators if
1452 ** New `Xmethods' feature in the Python API. Xmethods are
1453 additional methods or replacements for existing methods of a C++
1454 class. This feature is useful for those cases where a method
1455 defined in C++ source code could be inlined or optimized out by
1456 the compiler, making it unavailable to GDB.
1459 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1461 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1462 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1463 its alias "share", instead.
1465 * The commands "set remotebaud" and "show remotebaud" are no longer
1466 supported. Use "set serial baud" and "show serial baud" (respectively)
1471 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1472 target-async". The latter is left as a deprecated alias of the
1473 former for backward compatibility. If the target supports it,
1474 CLI background execution commands are now always possible by
1475 default, independently of whether the frontend stated a
1476 preference for asynchronous execution with "-gdb-set mi-async".
1477 Previously "-gdb-set target-async off" affected both MI execution
1478 commands and CLI execution commands.
1480 *** Changes in GDB 7.7
1482 * Improved support for process record-replay and reverse debugging on
1483 arm*-linux* targets. Support for thumb32 and syscall instruction
1484 recording has been added.
1486 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1488 * GDB now supports Fission DWP file format version 2.
1489 http://gcc.gnu.org/wiki/DebugFission
1491 * New convenience function "$_isvoid", to check whether an expression
1492 is void. A void expression is an expression where the type of the
1493 result is "void". For example, some convenience variables may be
1494 "void" when evaluated (e.g., "$_exitcode" before the execution of
1495 the program being debugged; or an undefined convenience variable).
1496 Another example, when calling a function whose return type is
1499 * The "maintenance print objfiles" command now takes an optional regexp.
1501 * The "catch syscall" command now works on arm*-linux* targets.
1503 * GDB now consistently shows "<not saved>" when printing values of
1504 registers the debug info indicates have not been saved in the frame
1505 and there's nowhere to retrieve them from
1506 (callee-saved/call-clobbered registers):
1511 (gdb) info registers rax
1514 Before, the former would print "<optimized out>", and the latter
1515 "*value not available*".
1517 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1522 ** Frame filters and frame decorators have been added.
1523 ** Temporary breakpoints are now supported.
1524 ** Line tables representation has been added.
1525 ** New attribute 'parent_type' for gdb.Field objects.
1526 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1527 ** New attribute 'name' for gdb.Type objects.
1531 Nios II ELF nios2*-*-elf
1532 Nios II GNU/Linux nios2*-*-linux
1533 Texas Instruments MSP430 msp430*-*-elf
1535 * Removed native configurations
1537 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1538 been removed. ELF variants of these configurations are kept supported.
1540 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1541 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1542 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1543 i[34567]86-*-openbsd3.[0-3]
1544 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1545 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1546 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1550 Like "catch throw", but catches a re-thrown exception.
1551 maint check-psymtabs
1552 Renamed from old "maint check-symtabs".
1554 Perform consistency checks on symtabs.
1555 maint expand-symtabs
1556 Expand symtabs matching an optional regexp.
1559 Display the details of GDB configure-time options.
1561 maint set|show per-command
1562 maint set|show per-command space
1563 maint set|show per-command time
1564 maint set|show per-command symtab
1565 Enable display of per-command gdb resource usage.
1567 remove-symbol-file FILENAME
1568 remove-symbol-file -a ADDRESS
1569 Remove a symbol file added via add-symbol-file. The file to remove
1570 can be identified by its filename or by an address that lies within
1571 the boundaries of this symbol file in memory.
1574 info exceptions REGEXP
1575 Display the list of Ada exceptions defined in the program being
1576 debugged. If provided, only the exceptions whose names match REGEXP
1581 set debug symfile off|on
1583 Control display of debugging info regarding reading symbol files and
1584 symbol tables within those files
1586 set print raw frame-arguments
1587 show print raw frame-arguments
1588 Set/show whether to print frame arguments in raw mode,
1589 disregarding any defined pretty-printers.
1591 set remote trace-status-packet
1592 show remote trace-status-packet
1593 Set/show the use of remote protocol qTStatus packet.
1597 Control display of debugging messages related to Nios II targets.
1601 Control whether target-assisted range stepping is enabled.
1603 set startup-with-shell
1604 show startup-with-shell
1605 Specifies whether Unix child processes are started via a shell or
1610 Use the target memory cache for accesses to the code segment. This
1611 improves performance of remote debugging (particularly disassembly).
1613 * You can now use a literal value 'unlimited' for options that
1614 interpret 0 or -1 as meaning "unlimited". E.g., "set
1615 trace-buffer-size unlimited" is now an alias for "set
1616 trace-buffer-size -1" and "set height unlimited" is now an alias for
1619 * The "set debug symtab-create" debugging option of GDB has been changed to
1620 accept a verbosity level. 0 means "off", 1 provides basic debugging
1621 output, and values of 2 or greater provides more verbose output.
1623 * New command-line options
1625 Display the details of GDB configure-time options.
1627 * The command 'tsave' can now support new option '-ctf' to save trace
1628 buffer in Common Trace Format.
1630 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1633 * GDB now implements the the C++ 'typeid' operator.
1635 * The new convenience variable $_exception holds the exception being
1636 thrown or caught at an exception-related catchpoint.
1638 * The exception-related catchpoints, like "catch throw", now accept a
1639 regular expression which can be used to filter exceptions by type.
1641 * The new convenience variable $_exitsignal is automatically set to
1642 the terminating signal number when the program being debugged dies
1643 due to an uncaught signal.
1647 ** All MI commands now accept an optional "--language" option.
1648 Support for this feature can be verified by using the "-list-features"
1649 command, which should contain "language-option".
1651 ** The new command -info-gdb-mi-command allows the user to determine
1652 whether a GDB/MI command is supported or not.
1654 ** The "^error" result record returned when trying to execute an undefined
1655 GDB/MI command now provides a variable named "code" whose content is the
1656 "undefined-command" error code. Support for this feature can be verified
1657 by using the "-list-features" command, which should contain
1658 "undefined-command-error-code".
1660 ** The -trace-save MI command can optionally save trace buffer in Common
1663 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1665 ** The command -data-list-register-values now accepts an optional
1666 "--skip-unavailable" option. When used, only the available registers
1669 ** The new command -trace-frame-collected dumps collected variables,
1670 computed expressions, tvars, memory and registers in a traceframe.
1672 ** The commands -stack-list-locals, -stack-list-arguments and
1673 -stack-list-variables now accept an option "--skip-unavailable".
1674 When used, only the available locals or arguments are displayed.
1676 ** The -exec-run command now accepts an optional "--start" option.
1677 When used, the command follows the same semantics as the "start"
1678 command, stopping the program's execution at the start of its
1679 main subprogram. Support for this feature can be verified using
1680 the "-list-features" command, which should contain
1681 "exec-run-start-option".
1683 ** The new commands -catch-assert and -catch-exceptions insert
1684 catchpoints stopping the program when Ada exceptions are raised.
1686 ** The new command -info-ada-exceptions provides the equivalent of
1687 the new "info exceptions" command.
1689 * New system-wide configuration scripts
1690 A GDB installation now provides scripts suitable for use as system-wide
1691 configuration scripts for the following systems:
1695 * GDB now supports target-assigned range stepping with remote targets.
1696 This improves the performance of stepping source lines by reducing
1697 the number of control packets from/to GDB. See "New remote packets"
1700 * GDB now understands the element 'tvar' in the XML traceframe info.
1701 It has the id of the collected trace state variables.
1703 * On S/390 targets that provide the transactional-execution feature,
1704 the program interruption transaction diagnostic block (TDB) is now
1705 represented as a number of additional "registers" in GDB.
1707 * New remote packets
1711 The vCont packet supports a new 'r' action, that tells the remote
1712 stub to step through an address range itself, without GDB
1713 involvemement at each single-step.
1715 qXfer:libraries-svr4:read's annex
1716 The previously unused annex of the qXfer:libraries-svr4:read packet
1717 is now used to support passing an argument list. The remote stub
1718 reports support for this argument list to GDB's qSupported query.
1719 The defined arguments are "start" and "prev", used to reduce work
1720 necessary for library list updating, resulting in significant
1723 * New features in the GDB remote stub, GDBserver
1725 ** GDBserver now supports target-assisted range stepping. Currently
1726 enabled on x86/x86_64 GNU/Linux targets.
1728 ** GDBserver now adds element 'tvar' in the XML in the reply to
1729 'qXfer:traceframe-info:read'. It has the id of the collected
1730 trace state variables.
1732 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1735 * New 'z' formatter for printing and examining memory, this displays the
1736 value as hexadecimal zero padded on the left to the size of the type.
1738 * GDB can now use Windows x64 unwinding data.
1740 * The "set remotebaud" command has been replaced by "set serial baud".
1741 Similarly, "show remotebaud" has been replaced by "show serial baud".
1742 The "set remotebaud" and "show remotebaud" commands are still available
1743 to provide backward compatibility with older versions of GDB.
1745 *** Changes in GDB 7.6
1747 * Target record has been renamed to record-full.
1748 Record/replay is now enabled with the "record full" command.
1749 This also affects settings that are associated with full record/replay
1750 that have been moved from "set/show record" to "set/show record full":
1752 set|show record full insn-number-max
1753 set|show record full stop-at-limit
1754 set|show record full memory-query
1756 * A new record target "record-btrace" has been added. The new target
1757 uses hardware support to record the control-flow of a process. It
1758 does not support replaying the execution, but it implements the
1759 below new commands for investigating the recorded execution log.
1760 This new recording method can be enabled using:
1764 The "record-btrace" target is only available on Intel Atom processors
1765 and requires a Linux kernel 2.6.32 or later.
1767 * Two new commands have been added for record/replay to give information
1768 about the recorded execution without having to replay the execution.
1769 The commands are only supported by "record btrace".
1771 record instruction-history prints the execution history at
1772 instruction granularity
1774 record function-call-history prints the execution history at
1775 function granularity
1777 * New native configurations
1779 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1780 FreeBSD/powerpc powerpc*-*-freebsd
1781 x86_64/Cygwin x86_64-*-cygwin*
1782 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1786 ARM AArch64 aarch64*-*-elf
1787 ARM AArch64 GNU/Linux aarch64*-*-linux
1788 Lynx 178 PowerPC powerpc-*-lynx*178
1789 x86_64/Cygwin x86_64-*-cygwin*
1790 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1792 * If the configured location of system.gdbinit file (as given by the
1793 --with-system-gdbinit option at configure time) is in the
1794 data-directory (as specified by --with-gdb-datadir at configure
1795 time) or in one of its subdirectories, then GDB will look for the
1796 system-wide init file in the directory specified by the
1797 --data-directory command-line option.
1799 * New command line options:
1801 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1802 other initialization files, unlike -nx which disables all of them.
1804 * Removed command line options
1806 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1809 * The 'ptype' and 'whatis' commands now accept an argument to control
1812 * 'info proc' now works on some core files.
1816 ** Vectors can be created with gdb.Type.vector.
1818 ** Python's atexit.register now works in GDB.
1820 ** Types can be pretty-printed via a Python API.
1822 ** Python 3 is now supported (in addition to Python 2.4 or later)
1824 ** New class gdb.Architecture exposes GDB's internal representation
1825 of architecture in the Python API.
1827 ** New method Frame.architecture returns the gdb.Architecture object
1828 corresponding to the frame's architecture.
1830 * New Python-based convenience functions:
1832 ** $_memeq(buf1, buf2, length)
1833 ** $_streq(str1, str2)
1835 ** $_regex(str, regex)
1837 * The 'cd' command now defaults to using '~' (the home directory) if not
1840 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1841 default for GCC since November 2000.
1843 * The command 'forward-search' can now be abbreviated as 'fo'.
1845 * The command 'info tracepoints' can now display 'installed on target'
1846 or 'not installed on target' for each non-pending location of tracepoint.
1848 * New configure options
1850 --enable-libmcheck/--disable-libmcheck
1851 By default, development versions are built with -lmcheck on hosts
1852 that support it, in order to help track memory corruption issues.
1853 Release versions, on the other hand, are built without -lmcheck
1854 by default. The --enable-libmcheck/--disable-libmcheck configure
1855 options allow the user to override that default.
1856 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1857 This configure option allows the user to build GDB with
1858 libbabeltrace using which GDB can read Common Trace Format data.
1860 * New commands (for set/show, see "New options" below)
1863 Catch signals. This is similar to "handle", but allows commands and
1864 conditions to be attached.
1867 List the BFDs known to GDB.
1869 python-interactive [command]
1871 Start a Python interactive prompt, or evaluate the optional command
1872 and print the result of expressions.
1875 "py" is a new alias for "python".
1877 enable type-printer [name]...
1878 disable type-printer [name]...
1879 Enable or disable type printers.
1883 ** For the Renesas Super-H architecture, the "regs" command has been removed
1884 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1889 set print type methods (on|off)
1890 show print type methods
1891 Control whether method declarations are displayed by "ptype".
1892 The default is to show them.
1894 set print type typedefs (on|off)
1895 show print type typedefs
1896 Control whether typedef definitions are displayed by "ptype".
1897 The default is to show them.
1899 set filename-display basename|relative|absolute
1900 show filename-display
1901 Control the way in which filenames is displayed.
1902 The default is "relative", which preserves previous behavior.
1904 set trace-buffer-size
1905 show trace-buffer-size
1906 Request target to change the size of trace buffer.
1908 set remote trace-buffer-size-packet auto|on|off
1909 show remote trace-buffer-size-packet
1910 Control the use of the remote protocol `QTBuffer:size' packet.
1914 Control display of debugging messages related to ARM AArch64.
1917 set debug coff-pe-read
1918 show debug coff-pe-read
1919 Control display of debugging messages related to reading of COFF/PE
1924 Control display of debugging messages related to Mach-O symbols
1927 set debug notification
1928 show debug notification
1929 Control display of debugging info for async remote notification.
1933 ** Command parameter changes are now notified using new async record
1934 "=cmd-param-changed".
1935 ** Trace frame changes caused by command "tfind" are now notified using
1936 new async record "=traceframe-changed".
1937 ** The creation, deletion and modification of trace state variables
1938 are now notified using new async records "=tsv-created",
1939 "=tsv-deleted" and "=tsv-modified".
1940 ** The start and stop of process record are now notified using new
1941 async record "=record-started" and "=record-stopped".
1942 ** Memory changes are now notified using new async record
1944 ** The data-disassemble command response will include a "fullname" field
1945 containing the absolute file name when source has been requested.
1946 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1947 command, to allow pattern filling of memory areas.
1948 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1949 library load/unload events.
1950 ** The response to breakpoint commands and breakpoint async records
1951 includes an "installed" field containing a boolean state about each
1952 non-pending tracepoint location is whether installed on target or not.
1953 ** Output of the "-trace-status" command includes a "trace-file" field
1954 containing the name of the trace file being examined. This field is
1955 optional, and only present when examining a trace file.
1956 ** The "fullname" field is now always present along with the "file" field,
1957 even if the file cannot be found by GDB.
1959 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1960 You must have the LZMA library available when configuring GDB for this
1961 feature to be enabled. For more information, see:
1962 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1964 * New remote packets
1967 Set the size of trace buffer. The remote stub reports support for this
1968 packet to gdb's qSupported query.
1971 Enable Branch Trace Store (BTS)-based branch tracing for the current
1972 thread. The remote stub reports support for this packet to gdb's
1976 Disable branch tracing for the current thread. The remote stub reports
1977 support for this packet to gdb's qSupported query.
1980 Read the traced branches for the current thread. The remote stub
1981 reports support for this packet to gdb's qSupported query.
1983 *** Changes in GDB 7.5
1985 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1986 for more x32 ABI info.
1988 * GDB now supports access to MIPS DSP registers on Linux targets.
1990 * GDB now supports debugging microMIPS binaries.
1992 * The "info os" command on GNU/Linux can now display information on
1993 several new classes of objects managed by the operating system:
1994 "info os procgroups" lists process groups
1995 "info os files" lists file descriptors
1996 "info os sockets" lists internet-domain sockets
1997 "info os shm" lists shared-memory regions
1998 "info os semaphores" lists semaphores
1999 "info os msg" lists message queues
2000 "info os modules" lists loaded kernel modules
2002 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2003 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2004 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2005 options and inspect the probe arguments using the new $_probe_arg family
2006 of convenience variables. You can obtain more information about SystemTap
2007 in <http://sourceware.org/systemtap/>.
2009 * GDB now supports reversible debugging on ARM, it allows you to
2010 debug basic ARM and THUMB instructions, and provides
2011 record/replay support.
2013 * The option "symbol-reloading" has been deleted as it is no longer used.
2017 ** GDB commands implemented in Python can now be put in command class
2020 ** The "maint set python print-stack on|off" is now deleted.
2022 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2023 apply "flag enum"-style pretty-printing to any enum.
2025 ** gdb.lookup_symbol can now work when there is no current frame.
2027 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2028 the source at which the symbol was defined.
2030 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2031 method 'value'. The former indicates whether the symbol needs a
2032 frame in order to compute its value, and the latter computes the
2035 ** A new method 'referenced_value' on gdb.Value objects which can
2036 dereference pointer as well as C++ reference values.
2038 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2039 which return the global and static blocks (as gdb.Block objects),
2040 of the underlying symbol table, respectively.
2042 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2043 object associated with a PC value.
2045 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2046 of the address range occupied by code for the current source line.
2048 * Go language support.
2049 GDB now supports debugging programs written in the Go programming
2052 * GDBserver now supports stdio connections.
2053 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2055 * The binary "gdbtui" can no longer be built or installed.
2056 Use "gdb -tui" instead.
2058 * GDB will now print "flag" enums specially. A flag enum is one where
2059 all the enumerator values have no bits in common when pairwise
2060 "and"ed. When printing a value whose type is a flag enum, GDB will
2061 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2062 (gdb) print (enum E) 3
2065 * The filename part of a linespec will now match trailing components
2066 of a source file name. For example, "break gcc/expr.c:1000" will
2067 now set a breakpoint in build/gcc/expr.c, but not
2068 build/libcpp/expr.c.
2070 * The "info proc" and "generate-core-file" commands will now also
2071 work on remote targets connected to GDBserver on Linux.
2073 * The command "info catch" has been removed. It has been disabled
2074 since December 2007.
2076 * The "catch exception" and "catch assert" commands now accept
2077 a condition at the end of the command, much like the "break"
2078 command does. For instance:
2080 (gdb) catch exception Constraint_Error if Barrier = True
2082 Previously, it was possible to add a condition to such catchpoints,
2083 but it had to be done as a second step, after the catchpoint had been
2084 created, using the "condition" command.
2086 * The "info static-tracepoint-marker" command will now also work on
2087 native Linux targets with in-process agent.
2089 * GDB can now set breakpoints on inlined functions.
2091 * The .gdb_index section has been updated to include symbols for
2092 inlined functions. GDB will ignore older .gdb_index sections by
2093 default, which could cause symbol files to be loaded more slowly
2094 until their .gdb_index sections can be recreated. The new command
2095 "set use-deprecated-index-sections on" will cause GDB to use any older
2096 .gdb_index sections it finds. This will restore performance, but the
2097 ability to set breakpoints on inlined functions will be lost in symbol
2098 files with older .gdb_index sections.
2100 The .gdb_index section has also been updated to record more information
2101 about each symbol. This speeds up the "info variables", "info functions"
2102 and "info types" commands when used with programs having the .gdb_index
2103 section, as well as speeding up debugging with shared libraries using
2104 the .gdb_index section.
2106 * Ada support for GDB/MI Variable Objects has been added.
2108 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2113 ** New command -info-os is the MI equivalent of "info os".
2115 ** Output logs ("set logging" and related) now include MI output.
2119 ** "set use-deprecated-index-sections on|off"
2120 "show use-deprecated-index-sections on|off"
2121 Controls the use of deprecated .gdb_index sections.
2123 ** "catch load" and "catch unload" can be used to stop when a shared
2124 library is loaded or unloaded, respectively.
2126 ** "enable count" can be used to auto-disable a breakpoint after
2129 ** "info vtbl" can be used to show the virtual method tables for
2130 C++ and Java objects.
2132 ** "explore" and its sub commands "explore value" and "explore type"
2133 can be used to recursively explore values and types of
2134 expressions. These commands are available only if GDB is
2135 configured with '--with-python'.
2137 ** "info auto-load" shows status of all kinds of auto-loaded files,
2138 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2139 sequences of commands files, "info auto-load python-scripts"
2140 shows status of auto-loading Python script files,
2141 "info auto-load local-gdbinit" shows status of loading init file
2142 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2143 status of inferior specific thread debugging shared library loading.
2145 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2146 and "show auto-load-scripts" commands have been deprecated, use their
2147 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2148 and "show auto-load python-scripts" counterparts instead.
2150 ** "dprintf location,format,args..." creates a dynamic printf, which
2151 is basically a breakpoint that does a printf and immediately
2152 resumes your program's execution, so it is like a printf that you
2153 can insert dynamically at runtime instead of at compiletime.
2155 ** "set print symbol"
2157 Controls whether GDB attempts to display the symbol, if any,
2158 corresponding to addresses it prints. This defaults to "on", but
2159 you can set it to "off" to restore GDB's previous behavior.
2161 * Deprecated commands
2163 ** For the Renesas Super-H architecture, the "regs" command has been
2164 deprecated, and "info all-registers" should be used instead.
2168 Renesas RL78 rl78-*-elf
2169 HP OpenVMS ia64 ia64-hp-openvms*
2171 * GDBserver supports evaluation of breakpoint conditions. When
2172 support is advertised by GDBserver, GDB may be told to send the
2173 breakpoint conditions in bytecode form to GDBserver. GDBserver
2174 will only report the breakpoint trigger to GDB when its condition
2179 set mips compression
2180 show mips compression
2181 Select the compressed ISA encoding used in functions that have no symbol
2182 information available. The encoding can be set to either of:
2185 and is updated automatically from ELF file flags if available.
2187 set breakpoint condition-evaluation
2188 show breakpoint condition-evaluation
2189 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2190 GDBserver ("target"). Default option "auto" chooses the most efficient
2192 This option can improve debugger efficiency depending on the speed of the
2196 Disable auto-loading globally.
2199 Show auto-loading setting of all kinds of auto-loaded files.
2201 set auto-load gdb-scripts on|off
2202 show auto-load gdb-scripts
2203 Control auto-loading of GDB canned sequences of commands files.
2205 set auto-load python-scripts on|off
2206 show auto-load python-scripts
2207 Control auto-loading of Python script files.
2209 set auto-load local-gdbinit on|off
2210 show auto-load local-gdbinit
2211 Control loading of init file (.gdbinit) from current directory.
2213 set auto-load libthread-db on|off
2214 show auto-load libthread-db
2215 Control auto-loading of inferior specific thread debugging shared library.
2217 set auto-load scripts-directory <dir1>[:<dir2>...]
2218 show auto-load scripts-directory
2219 Set a list of directories from which to load auto-loaded scripts.
2220 Automatically loaded Python scripts and GDB scripts are located in one
2221 of the directories listed by this option.
2222 The delimiter (':' above) may differ according to the host platform.
2224 set auto-load safe-path <dir1>[:<dir2>...]
2225 show auto-load safe-path
2226 Set a list of directories from which it is safe to auto-load files.
2227 The delimiter (':' above) may differ according to the host platform.
2229 set debug auto-load on|off
2230 show debug auto-load
2231 Control display of debugging info for auto-loading the files above.
2233 set dprintf-style gdb|call|agent
2235 Control the way in which a dynamic printf is performed; "gdb"
2236 requests a GDB printf command, while "call" causes dprintf to call a
2237 function in the inferior. "agent" requests that the target agent
2238 (such as GDBserver) do the printing.
2240 set dprintf-function <expr>
2241 show dprintf-function
2242 set dprintf-channel <expr>
2243 show dprintf-channel
2244 Set the function and optional first argument to the call when using
2245 the "call" style of dynamic printf.
2247 set disconnected-dprintf on|off
2248 show disconnected-dprintf
2249 Control whether agent-style dynamic printfs continue to be in effect
2250 after GDB disconnects.
2252 * New configure options
2254 --with-auto-load-dir
2255 Configure default value for the 'set auto-load scripts-directory'
2256 setting above. It defaults to '$debugdir:$datadir/auto-load',
2257 $debugdir representing global debugging info directories (available
2258 via 'show debug-file-directory') and $datadir representing GDB's data
2259 directory (available via 'show data-directory').
2261 --with-auto-load-safe-path
2262 Configure default value for the 'set auto-load safe-path' setting
2263 above. It defaults to the --with-auto-load-dir setting.
2265 --without-auto-load-safe-path
2266 Set 'set auto-load safe-path' to '/', effectively disabling this
2269 * New remote packets
2271 z0/z1 conditional breakpoints extension
2273 The z0/z1 breakpoint insertion packets have been extended to carry
2274 a list of conditional expressions over to the remote stub depending on the
2275 condition evaluation mode. The use of this extension can be controlled
2276 via the "set remote conditional-breakpoints-packet" command.
2280 Specify the signals which the remote stub may pass to the debugged
2281 program without GDB involvement.
2283 * New command line options
2285 --init-command=FILE, -ix Like --command, -x but execute it
2286 before loading inferior.
2287 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2288 execute it before loading inferior.
2290 *** Changes in GDB 7.4
2292 * GDB now handles ambiguous linespecs more consistently; the existing
2293 FILE:LINE support has been expanded to other types of linespecs. A
2294 breakpoint will now be set on all matching locations in all
2295 inferiors, and locations will be added or removed according to
2298 * GDB now allows you to skip uninteresting functions and files when
2299 stepping with the "skip function" and "skip file" commands.
2301 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2302 and "show remote hardware-watchpoint-length-limit". These allows to
2303 set or show the maximum length limit (in bytes) of a remote
2304 target hardware watchpoint.
2306 This allows e.g. to use "unlimited" hardware watchpoints with the
2307 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2308 watchpoints are slower than real hardware watchpoints but are
2309 significantly faster than gdb software watchpoints.
2313 ** The register_pretty_printer function in module gdb.printing now takes
2314 an optional `replace' argument. If True, the new printer replaces any
2317 ** The "maint set python print-stack on|off" command has been
2318 deprecated and will be deleted in GDB 7.5.
2319 A new command: "set python print-stack none|full|message" has
2320 replaced it. Additionally, the default for "print-stack" is
2321 now "message", which just prints the error message without
2324 ** A prompt substitution hook (prompt_hook) is now available to the
2327 ** A new Python module, gdb.prompt has been added to the GDB Python
2328 modules library. This module provides functionality for
2329 escape sequences in prompts (used by set/show
2330 extended-prompt). These escape sequences are replaced by their
2331 corresponding value.
2333 ** Python commands and convenience-functions located in
2334 'data-directory'/python/gdb/command and
2335 'data-directory'/python/gdb/function are now automatically loaded
2338 ** Blocks now provide four new attributes. global_block and
2339 static_block will return the global and static blocks
2340 respectively. is_static and is_global are boolean attributes
2341 that indicate if the block is one of those two types.
2343 ** Symbols now provide the "type" attribute, the type of the symbol.
2345 ** The "gdb.breakpoint" function has been deprecated in favor of
2348 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2349 of a function. This class is based on the "finish" command
2350 available in the CLI.
2352 ** Type objects for struct and union types now allow access to
2353 the fields using standard Python dictionary (mapping) methods.
2354 For example, "some_type['myfield']" now works, as does
2355 "some_type.items()".
2357 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2360 ** A new function, "deep_items" has been added to the gdb.types
2361 module in the GDB Python modules library. This function returns
2362 an iterator over the fields of a struct or union type. Unlike
2363 the standard Python "iteritems" method, it will recursively traverse
2364 any anonymous fields.
2368 ** "*stopped" events can report several new "reason"s, such as
2371 ** Breakpoint changes are now notified using new async records, like
2372 "=breakpoint-modified".
2374 ** New command -ada-task-info.
2376 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2377 $sdir specifies the default system locations of shared libraries.
2378 $pdir specifies the directory where the libpthread used by the application
2381 GDB no longer looks in $sdir and $pdir after it has searched the directories
2382 mentioned in libthread-db-search-path. If you want to search those
2383 directories, they must be specified in libthread-db-search-path.
2384 The default value of libthread-db-search-path on GNU/Linux and Solaris
2385 systems is now "$sdir:$pdir".
2387 $pdir is not supported by gdbserver, it is currently ignored.
2388 $sdir is supported by gdbserver.
2390 * New configure option --with-iconv-bin.
2391 When using the internationalization support like the one in the GNU C
2392 library, GDB will invoke the "iconv" program to get a list of supported
2393 character sets. If this program lives in a non-standard location, one can
2394 use this option to specify where to find it.
2396 * When natively debugging programs on PowerPC BookE processors running
2397 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2398 watchpoints, which specify a mask in addition to an address to watch.
2399 The mask specifies that some bits of an address (the bits which are
2400 reset in the mask) should be ignored when matching the address accessed
2401 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2402 section in the user manual for more details.
2404 * The new option --once causes GDBserver to stop listening for connections once
2405 the first connection is made. The listening port used by GDBserver will
2406 become available after that.
2408 * New commands "info macros" and "alias" have been added.
2410 * New function parameters suffix @entry specifies value of function parameter
2411 at the time the function got called. Entry values are available only since
2417 "!" is now an alias of the "shell" command.
2418 Note that no space is needed between "!" and SHELL COMMAND.
2422 watch EXPRESSION mask MASK_VALUE
2423 The watch command now supports the mask argument which allows creation
2424 of masked watchpoints, if the current architecture supports this feature.
2426 info auto-load-scripts [REGEXP]
2427 This command was formerly named "maintenance print section-scripts".
2428 It is now generally useful and is no longer a maintenance-only command.
2430 info macro [-all] [--] MACRO
2431 The info macro command has new options `-all' and `--'. The first for
2432 printing all definitions of a macro. The second for explicitly specifying
2433 the end of arguments and the beginning of the macro name in case the macro
2434 name starts with a hyphen.
2436 collect[/s] EXPRESSIONS
2437 The tracepoint collect command now takes an optional modifier "/s"
2438 that directs it to dereference pointer-to-character types and
2439 collect the bytes of memory up to a zero byte. The behavior is
2440 similar to what you see when you use the regular print command on a
2441 string. An optional integer following the "/s" sets a bound on the
2442 number of bytes that will be collected.
2445 The trace start command now interprets any supplied arguments as a
2446 note to be recorded with the trace run, with an effect similar to
2447 setting the variable trace-notes.
2450 The trace stop command now interprets any arguments as a note to be
2451 mentioned along with the tstatus report that the trace was stopped
2452 with a command. The effect is similar to setting the variable
2455 * Tracepoints can now be enabled and disabled at any time after a trace
2456 experiment has been started using the standard "enable" and "disable"
2457 commands. It is now possible to start a trace experiment with no enabled
2458 tracepoints; GDB will display a warning, but will allow the experiment to
2459 begin, assuming that tracepoints will be enabled as needed while the trace
2462 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2463 locations with 4-byte instructions, when they were previously
2464 limited to locations with instructions of 5 bytes or longer.
2468 set debug dwarf2-read
2469 show debug dwarf2-read
2470 Turns on or off display of debugging messages related to reading
2471 DWARF debug info. The default is off.
2473 set debug symtab-create
2474 show debug symtab-create
2475 Turns on or off display of debugging messages related to symbol table
2476 creation. The default is off.
2479 show extended-prompt
2480 Set the GDB prompt, and allow escape sequences to be inserted to
2481 display miscellaneous information (see 'help set extended-prompt'
2482 for the list of sequences). This prompt (and any information
2483 accessed through the escape sequences) is updated every time the
2484 prompt is displayed.
2486 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2487 show print entry-values
2488 Set printing of frame argument values at function entry. In some cases
2489 GDB can determine the value of function argument which was passed by the
2490 function caller, even if the value was modified inside the called function.
2492 set debug entry-values
2493 show debug entry-values
2494 Control display of debugging info for determining frame argument values at
2495 function entry and virtual tail call frames.
2497 set basenames-may-differ
2498 show basenames-may-differ
2499 Set whether a source file may have multiple base names.
2500 (A "base name" is the name of a file with the directory part removed.
2501 Example: The base name of "/home/user/hello.c" is "hello.c".)
2502 If set, GDB will canonicalize file names (e.g., expand symlinks)
2503 before comparing them. Canonicalization is an expensive operation,
2504 but it allows the same file be known by more than one base name.
2505 If not set (the default), all source files are assumed to have just
2506 one base name, and gdb will do file name comparisons more efficiently.
2512 Set a user name and notes for the current and any future trace runs.
2513 This is useful for long-running and/or disconnected traces, to
2514 inform others (or yourself) as to who is running the trace, supply
2515 contact information, or otherwise explain what is going on.
2517 set trace-stop-notes
2518 show trace-stop-notes
2519 Set a note attached to the trace run, that is displayed when the
2520 trace has been stopped by a tstop command. This is useful for
2521 instance as an explanation, if you are stopping a trace run that was
2522 started by someone else.
2524 * New remote packets
2528 Dynamically enable a tracepoint in a started trace experiment.
2532 Dynamically disable a tracepoint in a started trace experiment.
2536 Set the user and notes of the trace run.
2540 Query the current status of a tracepoint.
2544 Query the minimum length of instruction at which a fast tracepoint may
2547 * Dcache size (number of lines) and line-size are now runtime-configurable
2548 via "set dcache line" and "set dcache line-size" commands.
2552 Texas Instruments TMS320C6x tic6x-*-*
2556 Renesas RL78 rl78-*-elf
2558 *** Changes in GDB 7.3.1
2560 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2562 *** Changes in GDB 7.3
2564 * GDB has a new command: "thread find [REGEXP]".
2565 It finds the thread id whose name, target id, or thread extra info
2566 matches the given regular expression.
2568 * The "catch syscall" command now works on mips*-linux* targets.
2570 * The -data-disassemble MI command now supports modes 2 and 3 for
2571 dumping the instruction opcodes.
2573 * New command line options
2575 -data-directory DIR Specify DIR as the "data-directory".
2576 This is mostly for testing purposes.
2578 * The "maint set python auto-load on|off" command has been renamed to
2579 "set auto-load-scripts on|off".
2581 * GDB has a new command: "set directories".
2582 It is like the "dir" command except that it replaces the
2583 source path list instead of augmenting it.
2585 * GDB now understands thread names.
2587 On GNU/Linux, "info threads" will display the thread name as set by
2588 prctl or pthread_setname_np.
2590 There is also a new command, "thread name", which can be used to
2591 assign a name internally for GDB to display.
2594 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2595 has been integrated into GDB.
2599 ** The function gdb.Write now accepts an optional keyword 'stream'.
2600 This keyword, when provided, will direct the output to either
2601 stdout, stderr, or GDB's logging output.
2603 ** Parameters can now be be sub-classed in Python, and in particular
2604 you may implement the get_set_doc and get_show_doc functions.
2605 This improves how Parameter set/show documentation is processed
2606 and allows for more dynamic content.
2608 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2609 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2610 have an is_valid method.
2612 ** Breakpoints can now be sub-classed in Python, and in particular
2613 you may implement a 'stop' function that is executed each time
2614 the inferior reaches that breakpoint.
2616 ** New function gdb.lookup_global_symbol looks up a global symbol.
2618 ** GDB values in Python are now callable if the value represents a
2619 function. For example, if 'some_value' represents a function that
2620 takes two integer parameters and returns a value, you can call
2621 that function like so:
2623 result = some_value (10,20)
2625 ** Module gdb.types has been added.
2626 It contains a collection of utilities for working with gdb.Types objects:
2627 get_basic_type, has_field, make_enum_dict.
2629 ** Module gdb.printing has been added.
2630 It contains utilities for writing and registering pretty-printers.
2631 New classes: PrettyPrinter, SubPrettyPrinter,
2632 RegexpCollectionPrettyPrinter.
2633 New function: register_pretty_printer.
2635 ** New commands "info pretty-printers", "enable pretty-printer" and
2636 "disable pretty-printer" have been added.
2638 ** gdb.parameter("directories") is now available.
2640 ** New function gdb.newest_frame returns the newest frame in the
2643 ** The gdb.InferiorThread class has a new "name" attribute. This
2644 holds the thread's name.
2646 ** Python Support for Inferior events.
2647 Python scripts can add observers to be notified of events
2648 occurring in the process being debugged.
2649 The following events are currently supported:
2650 - gdb.events.cont Continue event.
2651 - gdb.events.exited Inferior exited event.
2652 - gdb.events.stop Signal received, and Breakpoint hit events.
2656 ** GDB now puts template parameters in scope when debugging in an
2657 instantiation. For example, if you have:
2659 template<int X> int func (void) { return X; }
2661 then if you step into func<5>, "print X" will show "5". This
2662 feature requires proper debuginfo support from the compiler; it
2663 was added to GCC 4.5.
2665 ** The motion commands "next", "finish", "until", and "advance" now
2666 work better when exceptions are thrown. In particular, GDB will
2667 no longer lose control of the inferior; instead, the GDB will
2668 stop the inferior at the point at which the exception is caught.
2669 This functionality requires a change in the exception handling
2670 code that was introduced in GCC 4.5.
2672 * GDB now follows GCC's rules on accessing volatile objects when
2673 reading or writing target state during expression evaluation.
2674 One notable difference to prior behavior is that "print x = 0"
2675 no longer generates a read of x; the value of the assignment is
2676 now always taken directly from the value being assigned.
2678 * GDB now has some support for using labels in the program's source in
2679 linespecs. For instance, you can use "advance label" to continue
2680 execution to a label.
2682 * GDB now has support for reading and writing a new .gdb_index
2683 section. This section holds a fast index of DWARF debugging
2684 information and can be used to greatly speed up GDB startup and
2685 operation. See the documentation for `save gdb-index' for details.
2687 * The "watch" command now accepts an optional "-location" argument.
2688 When used, this causes GDB to watch the memory referred to by the
2689 expression. Such a watchpoint is never deleted due to it going out
2692 * GDB now supports thread debugging of core dumps on GNU/Linux.
2694 GDB now activates thread debugging using the libthread_db library
2695 when debugging GNU/Linux core dumps, similarly to when debugging
2696 live processes. As a result, when debugging a core dump file, GDB
2697 is now able to display pthread_t ids of threads. For example, "info
2698 threads" shows the same output as when debugging the process when it
2699 was live. In earlier releases, you'd see something like this:
2702 * 1 LWP 6780 main () at main.c:10
2704 While now you see this:
2707 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2709 It is also now possible to inspect TLS variables when debugging core
2712 When debugging a core dump generated on a machine other than the one
2713 used to run GDB, you may need to point GDB at the correct
2714 libthread_db library with the "set libthread-db-search-path"
2715 command. See the user manual for more details on this command.
2717 * When natively debugging programs on PowerPC BookE processors running
2718 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2719 which stop execution of the inferior whenever it executes an instruction
2720 at any address within the specified range. See the "PowerPC Embedded"
2721 section in the user manual for more details.
2723 * New features in the GDB remote stub, GDBserver
2725 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2726 and i686 LynxOS (version 5.x).
2728 ** GDBserver is now supported on Blackfin Linux.
2730 * New native configurations
2732 ia64 HP-UX ia64-*-hpux*
2736 Analog Devices, Inc. Blackfin Processor bfin-*
2738 * Ada task switching is now supported on sparc-elf targets when
2739 debugging a program using the Ravenscar Profile. For more information,
2740 see the "Tasking Support when using the Ravenscar Profile" section
2741 in the GDB user manual.
2743 * Guile support was removed.
2745 * New features in the GNU simulator
2747 ** The --map-info flag lists all known core mappings.
2749 ** CFI flashes may be simulated via the "cfi" device.
2751 *** Changes in GDB 7.2
2753 * Shared library support for remote targets by default
2755 When GDB is configured for a generic, non-OS specific target, like
2756 for example, --target=arm-eabi or one of the many *-*-elf targets,
2757 GDB now queries remote stubs for loaded shared libraries using the
2758 `qXfer:libraries:read' packet. Previously, shared library support
2759 was always disabled for such configurations.
2763 ** Argument Dependent Lookup (ADL)
2765 In C++ ADL lookup directs function search to the namespaces of its
2766 arguments even if the namespace has not been imported.
2776 Here the compiler will search for `foo' in the namespace of 'b'
2777 and find A::foo. GDB now supports this. This construct is commonly
2778 used in the Standard Template Library for operators.
2780 ** Improved User Defined Operator Support
2782 In addition to member operators, GDB now supports lookup of operators
2783 defined in a namespace and imported with a `using' directive, operators
2784 defined in the global scope, operators imported implicitly from an
2785 anonymous namespace, and the ADL operators mentioned in the previous
2787 GDB now also supports proper overload resolution for all the previously
2788 mentioned flavors of operators.
2790 ** static const class members
2792 Printing of static const class members that are initialized in the
2793 class definition has been fixed.
2795 * Windows Thread Information Block access.
2797 On Windows targets, GDB now supports displaying the Windows Thread
2798 Information Block (TIB) structure. This structure is visible either
2799 by using the new command `info w32 thread-information-block' or, by
2800 dereferencing the new convenience variable named `$_tlb', a
2801 thread-specific pointer to the TIB. This feature is also supported
2802 when remote debugging using GDBserver.
2804 * Static tracepoints
2806 Static tracepoints are calls in the user program into a tracing
2807 library. One such library is a port of the LTTng kernel tracer to
2808 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2809 When debugging with GDBserver, GDB now supports combining the GDB
2810 tracepoint machinery with such libraries. For example: the user can
2811 use GDB to probe a static tracepoint marker (a call from the user
2812 program into the tracing library) with the new "strace" command (see
2813 "New commands" below). This creates a "static tracepoint" in the
2814 breakpoint list, that can be manipulated with the same feature set
2815 as fast and regular tracepoints. E.g., collect registers, local and
2816 global variables, collect trace state variables, and define
2817 tracepoint conditions. In addition, the user can collect extra
2818 static tracepoint marker specific data, by collecting the new
2819 $_sdata internal variable. When analyzing the trace buffer, you can
2820 inspect $_sdata like any other variable available to GDB. For more
2821 information, see the "Tracepoints" chapter in GDB user manual. New
2822 remote packets have been defined to support static tracepoints, see
2823 the "New remote packets" section below.
2825 * Better reconstruction of tracepoints after disconnected tracing
2827 GDB will attempt to download the original source form of tracepoint
2828 definitions when starting a trace run, and then will upload these
2829 upon reconnection to the target, resulting in a more accurate
2830 reconstruction of the tracepoints that are in use on the target.
2834 You can now exercise direct control over the ways that GDB can
2835 affect your program. For instance, you can disallow the setting of
2836 breakpoints, so that the program can run continuously (assuming
2837 non-stop mode). In addition, the "observer" variable is available
2838 to switch all of the different controls; in observer mode, GDB
2839 cannot affect the target's behavior at all, which is useful for
2840 tasks like diagnosing live systems in the field.
2842 * The new convenience variable $_thread holds the number of the
2845 * New remote packets
2849 Return the address of the Windows Thread Information Block of a given thread.
2853 In response to several of the tracepoint packets, the target may now
2854 also respond with a number of intermediate `qRelocInsn' request
2855 packets before the final result packet, to have GDB handle
2856 relocating an instruction to execute at a different address. This
2857 is particularly useful for stubs that support fast tracepoints. GDB
2858 reports support for this feature in the qSupported packet.
2862 List static tracepoint markers in the target program.
2866 List static tracepoint markers at a given address in the target
2869 qXfer:statictrace:read
2871 Read the static trace data collected (by a `collect $_sdata'
2872 tracepoint action). The remote stub reports support for this packet
2873 to gdb's qSupported query.
2877 Send the current settings of GDB's permission flags.
2881 Send part of the source (textual) form of a tracepoint definition,
2882 which includes location, conditional, and action list.
2884 * The source command now accepts a -s option to force searching for the
2885 script in the source search path even if the script name specifies
2888 * New features in the GDB remote stub, GDBserver
2890 - GDBserver now support tracepoints (including fast tracepoints, and
2891 static tracepoints). The feature is currently supported by the
2892 i386-linux and amd64-linux builds. See the "Tracepoints support
2893 in gdbserver" section in the manual for more information.
2895 GDBserver JIT compiles the tracepoint's conditional agent
2896 expression bytecode into native code whenever possible for low
2897 overhead dynamic tracepoints conditionals. For such tracepoints,
2898 an expression that examines program state is evaluated when the
2899 tracepoint is reached, in order to determine whether to capture
2900 trace data. If the condition is simple and false, processing the
2901 tracepoint finishes very quickly and no data is gathered.
2903 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2904 for static tracepoints support.
2906 - GDBserver now supports x86_64 Windows 64-bit debugging.
2908 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2909 it understands register description.
2911 * The --batch flag now disables pagination and queries.
2913 * X86 general purpose registers
2915 GDB now supports reading/writing byte, word and double-word x86
2916 general purpose registers directly. This means you can use, say,
2917 $ah or $ax to refer, respectively, to the byte register AH and
2918 16-bit word register AX that are actually portions of the 32-bit
2919 register EAX or 64-bit register RAX.
2921 * The `commands' command now accepts a range of breakpoints to modify.
2922 A plain `commands' following a command that creates multiple
2923 breakpoints affects all the breakpoints set by that command. This
2924 applies to breakpoints set by `rbreak', and also applies when a
2925 single `break' command creates multiple breakpoints (e.g.,
2926 breakpoints on overloaded c++ functions).
2928 * The `rbreak' command now accepts a filename specification as part of
2929 its argument, limiting the functions selected by the regex to those
2930 in the specified file.
2932 * Support for remote debugging Windows and SymbianOS shared libraries
2933 from Unix hosts has been improved. Non Windows GDB builds now can
2934 understand target reported file names that follow MS-DOS based file
2935 system semantics, such as file names that include drive letters and
2936 use the backslash character as directory separator. This makes it
2937 possible to transparently use the "set sysroot" and "set
2938 solib-search-path" on Unix hosts to point as host copies of the
2939 target's shared libraries. See the new command "set
2940 target-file-system-kind" described below, and the "Commands to
2941 specify files" section in the user manual for more information.
2945 eval template, expressions...
2946 Convert the values of one or more expressions under the control
2947 of the string template to a command line, and call it.
2949 set target-file-system-kind unix|dos-based|auto
2950 show target-file-system-kind
2951 Set or show the assumed file system kind for target reported file
2954 save breakpoints <filename>
2955 Save all current breakpoint definitions to a file suitable for use
2956 in a later debugging session. To read the saved breakpoint
2957 definitions, use the `source' command.
2959 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2962 info static-tracepoint-markers
2963 Display information about static tracepoint markers in the target.
2965 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2966 Define a static tracepoint by probing a marker at the given
2967 function, line, address, or marker ID.
2971 Enable and disable observer mode.
2973 set may-write-registers on|off
2974 set may-write-memory on|off
2975 set may-insert-breakpoints on|off
2976 set may-insert-tracepoints on|off
2977 set may-insert-fast-tracepoints on|off
2978 set may-interrupt on|off
2979 Set individual permissions for GDB effects on the target. Note that
2980 some of these settings can have undesirable or surprising
2981 consequences, particularly when changed in the middle of a session.
2982 For instance, disabling the writing of memory can prevent
2983 breakpoints from being inserted, cause single-stepping to fail, or
2984 even crash your program, if you disable after breakpoints have been
2985 inserted. However, GDB should not crash.
2987 set record memory-query on|off
2988 show record memory-query
2989 Control whether to stop the inferior if memory changes caused
2990 by an instruction cannot be recorded.
2995 The disassemble command now supports "start,+length" form of two arguments.
2999 ** GDB now provides a new directory location, called the python directory,
3000 where Python scripts written for GDB can be installed. The location
3001 of that directory is <data-directory>/python, where <data-directory>
3002 is the GDB data directory. For more details, see section `Scripting
3003 GDB using Python' in the manual.
3005 ** The GDB Python API now has access to breakpoints, symbols, symbol
3006 tables, program spaces, inferiors, threads and frame's code blocks.
3007 Additionally, GDB Parameters can now be created from the API, and
3008 manipulated via set/show in the CLI.
3010 ** New functions gdb.target_charset, gdb.target_wide_charset,
3011 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3013 ** New exception gdb.GdbError.
3015 ** Pretty-printers are now also looked up in the current program space.
3017 ** Pretty-printers can now be individually enabled and disabled.
3019 ** GDB now looks for names of Python scripts to auto-load in a
3020 special section named `.debug_gdb_scripts', in addition to looking
3021 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3023 * Tracepoint actions were unified with breakpoint commands. In particular,
3024 there are no longer differences in "info break" output for breakpoints and
3025 tracepoints and the "commands" command can be used for both tracepoints and
3026 regular breakpoints.
3030 ARM Symbian arm*-*-symbianelf*
3032 * D language support.
3033 GDB now supports debugging programs written in the D programming
3036 * GDB now supports the extended ptrace interface for PowerPC which is
3037 available since Linux kernel version 2.6.34. This automatically enables
3038 any hardware breakpoints and additional hardware watchpoints available in
3039 the processor. The old ptrace interface exposes just one hardware
3040 watchpoint and no hardware breakpoints.
3042 * GDB is now able to use the Data Value Compare (DVC) register available on
3043 embedded PowerPC processors to implement in hardware simple watchpoint
3044 conditions of the form:
3046 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3048 This works in native GDB running on Linux kernels with the extended ptrace
3049 interface mentioned above.
3051 *** Changes in GDB 7.1
3055 ** Namespace Support
3057 GDB now supports importing of namespaces in C++. This enables the
3058 user to inspect variables from imported namespaces. Support for
3059 namepace aliasing has also been added. So, if a namespace is
3060 aliased in the current scope (e.g. namepace C=A; ) the user can
3061 print variables using the alias (e.g. (gdb) print C::x).
3065 All known bugs relating to the printing of virtual base class were
3066 fixed. It is now possible to call overloaded static methods using a
3071 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3072 and reinterpret_cast<> are now handled by the C++ expression parser.
3076 Xilinx MicroBlaze microblaze-*-*
3081 Xilinx MicroBlaze microblaze
3084 * Multi-program debugging.
3086 GDB now has support for multi-program (a.k.a. multi-executable or
3087 multi-exec) debugging. This allows for debugging multiple inferiors
3088 simultaneously each running a different program under the same GDB
3089 session. See "Debugging Multiple Inferiors and Programs" in the
3090 manual for more information. This implied some user visible changes
3091 in the multi-inferior support. For example, "info inferiors" now
3092 lists inferiors that are not running yet or that have exited
3093 already. See also "New commands" and "New options" below.
3095 * New tracing features
3097 GDB's tracepoint facility now includes several new features:
3099 ** Trace state variables
3101 GDB tracepoints now include support for trace state variables, which
3102 are variables managed by the target agent during a tracing
3103 experiment. They are useful for tracepoints that trigger each
3104 other, so for instance one tracepoint can count hits in a variable,
3105 and then a second tracepoint has a condition that is true when the
3106 count reaches a particular value. Trace state variables share the
3107 $-syntax of GDB convenience variables, and can appear in both
3108 tracepoint actions and condition expressions. Use the "tvariable"
3109 command to create, and "info tvariables" to view; see "Trace State
3110 Variables" in the manual for more detail.
3114 GDB now includes an option for defining fast tracepoints, which
3115 targets may implement more efficiently, such as by installing a jump
3116 into the target agent rather than a trap instruction. The resulting
3117 speedup can be by two orders of magnitude or more, although the
3118 tradeoff is that some program locations on some target architectures
3119 might not allow fast tracepoint installation, for instance if the
3120 instruction to be replaced is shorter than the jump. To request a
3121 fast tracepoint, use the "ftrace" command, with syntax identical to
3122 the regular trace command.
3124 ** Disconnected tracing
3126 It is now possible to detach GDB from the target while it is running
3127 a trace experiment, then reconnect later to see how the experiment
3128 is going. In addition, a new variable disconnected-tracing lets you
3129 tell the target agent whether to continue running a trace if the
3130 connection is lost unexpectedly.
3134 GDB now has the ability to save the trace buffer into a file, and
3135 then use that file as a target, similarly to you can do with
3136 corefiles. You can select trace frames, print data that was
3137 collected in them, and use tstatus to display the state of the
3138 tracing run at the moment that it was saved. To create a trace
3139 file, use "tsave <filename>", and to use it, do "target tfile
3142 ** Circular trace buffer
3144 You can ask the target agent to handle the trace buffer as a
3145 circular buffer, discarding the oldest trace frames to make room for
3146 newer ones, by setting circular-trace-buffer to on. This feature may
3147 not be available for all target agents.
3152 The disassemble command, when invoked with two arguments, now requires
3153 the arguments to be comma-separated.
3156 The info variables command now displays variable definitions. Files
3157 which only declare a variable are not shown.
3160 The source command is now capable of sourcing Python scripts.
3161 This feature is dependent on the debugger being build with Python
3164 Related to this enhancement is also the introduction of a new command
3165 "set script-extension" (see below).
3167 * New commands (for set/show, see "New options" below)
3169 record save [<FILENAME>]
3170 Save a file (in core file format) containing the process record
3171 execution log for replay debugging at a later time.
3173 record restore <FILENAME>
3174 Restore the process record execution log that was saved at an
3175 earlier time, for replay debugging.
3177 add-inferior [-copies <N>] [-exec <FILENAME>]
3180 clone-inferior [-copies <N>] [ID]
3181 Make a new inferior ready to execute the same program another
3182 inferior has loaded.
3187 maint info program-spaces
3188 List the program spaces loaded into GDB.
3190 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3191 show remote interrupt-sequence
3192 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3193 as the sequence to the remote target in order to interrupt the execution.
3194 Ctrl-C is a default. Some system prefers BREAK which is high level of
3195 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3196 Magic SysRq g. It is BREAK signal and character 'g'.
3198 set remote interrupt-on-connect [on | off]
3199 show remote interrupt-on-connect
3200 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3201 remote target when gdb connects to it. This is needed when you debug
3204 set remotebreak [on | off]
3206 Deprecated. Use "set/show remote interrupt-sequence" instead.
3208 tvariable $NAME [ = EXP ]
3209 Create or modify a trace state variable.
3212 List trace state variables and their values.
3214 delete tvariable $NAME ...
3215 Delete one or more trace state variables.
3218 Evaluate the given expressions without collecting anything into the
3219 trace buffer. (Valid in tracepoint actions only.)
3221 ftrace FN / FILE:LINE / *ADDR
3222 Define a fast tracepoint at the given function, line, or address.
3224 * New expression syntax
3226 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3227 GDB now parses 0b101010 identically with 42.
3231 set follow-exec-mode new|same
3232 show follow-exec-mode
3233 Control whether GDB reuses the same inferior across an exec call or
3234 creates a new one. This is useful to be able to restart the old
3235 executable after the inferior having done an exec call.
3237 set default-collect EXPR, ...
3238 show default-collect
3239 Define a list of expressions to be collected at each tracepoint.
3240 This is a useful way to ensure essential items are not overlooked,
3241 such as registers or a critical global variable.
3243 set disconnected-tracing
3244 show disconnected-tracing
3245 If set to 1, the target is instructed to continue tracing if it
3246 loses its connection to GDB. If 0, the target is to stop tracing
3249 set circular-trace-buffer
3250 show circular-trace-buffer
3251 If set to on, the target is instructed to use a circular trace buffer
3252 and discard the oldest trace frames instead of stopping the trace due
3253 to a full trace buffer. If set to off, the trace stops when the buffer
3254 fills up. Some targets may not support this.
3256 set script-extension off|soft|strict
3257 show script-extension
3258 If set to "off", the debugger does not perform any script language
3259 recognition, and all sourced files are assumed to be GDB scripts.
3260 If set to "soft" (the default), files are sourced according to
3261 filename extension, falling back to GDB scripts if the first
3263 If set to "strict", files are sourced according to filename extension.
3265 set ada trust-PAD-over-XVS on|off
3266 show ada trust-PAD-over-XVS
3267 If off, activate a workaround against a bug in the debugging information
3268 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3269 the GCC sources for more information about the GNAT encoding and
3270 PAD types in particular). It is always safe to set this option to
3271 off, but this introduces a slight performance penalty. The default
3274 * Python API Improvements
3276 ** GDB provides the new class gdb.LazyString. This is useful in
3277 some pretty-printing cases. The new method gdb.Value.lazy_string
3278 provides a simple way to create objects of this type.
3280 ** The fields returned by gdb.Type.fields now have an
3281 `is_base_class' attribute.
3283 ** The new method gdb.Type.range returns the range of an array type.
3285 ** The new method gdb.parse_and_eval can be used to parse and
3286 evaluate an expression.
3288 * New remote packets
3291 Define a trace state variable.
3294 Get the current value of a trace state variable.
3297 Set desired tracing behavior upon disconnection.
3300 Set the trace buffer to be linear or circular.
3303 Get data about the tracepoints currently in use.
3307 Process record now works correctly with hardware watchpoints.
3309 Multiple bug fixes have been made to the mips-irix port, making it
3310 much more reliable. In particular:
3311 - Debugging threaded applications is now possible again. Previously,
3312 GDB would hang while starting the program, or while waiting for
3313 the program to stop at a breakpoint.
3314 - Attaching to a running process no longer hangs.
3315 - An error occurring while loading a core file has been fixed.
3316 - Changing the value of the PC register now works again. This fixes
3317 problems observed when using the "jump" command, or when calling
3318 a function from GDB, or even when assigning a new value to $pc.
3319 - With the "finish" and "return" commands, the return value for functions
3320 returning a small array is now correctly printed.
3321 - It is now possible to break on shared library code which gets executed
3322 during a shared library init phase (code executed while executing
3323 their .init section). Previously, the breakpoint would have no effect.
3324 - GDB is now able to backtrace through the signal handler for
3325 non-threaded programs.
3327 PIE (Position Independent Executable) programs debugging is now supported.
3328 This includes debugging execution of PIC (Position Independent Code) shared
3329 libraries although for that, it should be possible to run such libraries as an
3332 *** Changes in GDB 7.0
3334 * GDB now has an interface for JIT compilation. Applications that
3335 dynamically generate code can create symbol files in memory and register
3336 them with GDB. For users, the feature should work transparently, and
3337 for JIT developers, the interface is documented in the GDB manual in the
3338 "JIT Compilation Interface" chapter.
3340 * Tracepoints may now be conditional. The syntax is as for
3341 breakpoints; either an "if" clause appended to the "trace" command,
3342 or the "condition" command is available. GDB sends the condition to
3343 the target for evaluation using the same bytecode format as is used
3344 for tracepoint actions.
3346 * The disassemble command now supports: an optional /r modifier, print the
3347 raw instructions in hex as well as in symbolic form, and an optional /m
3348 modifier to print mixed source+assembly.
3350 * Process record and replay
3352 In a architecture environment that supports ``process record and
3353 replay'', ``process record and replay'' target can record a log of
3354 the process execution, and replay it with both forward and reverse
3357 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3358 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3359 set execution-direction {forward|reverse}, for targets that support
3362 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3363 feature is available with a native GDB running on kernel version
3366 * GDB now has support for multi-byte and wide character sets on the
3367 target. Strings whose character type is wchar_t, char16_t, or
3368 char32_t are now correctly printed. GDB supports wide- and unicode-
3369 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3370 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3371 `printf'. This feature requires iconv to work properly; if your
3372 system does not have a working iconv, GDB can use GNU libiconv. See
3373 the installation instructions for more information.
3375 * GDB now supports automatic retrieval of shared library files from
3376 remote targets. To use this feature, specify a system root that begins
3377 with the `remote:' prefix, either via the `set sysroot' command or via
3378 the `--with-sysroot' configure-time option.
3380 * "info sharedlibrary" now takes an optional regex of libraries to show,
3381 and it now reports if a shared library has no debugging information.
3383 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3384 now complete on file names.
3386 * When completing in expressions, gdb will attempt to limit
3387 completions to allowable structure or union fields, where appropriate.
3388 For instance, consider:
3390 # struct example { int f1; double f2; };
3391 # struct example variable;
3394 If the user types TAB at the end of this command line, the available
3395 completions will be "f1" and "f2".
3397 * Inlined functions are now supported. They show up in backtraces, and
3398 the "step", "next", and "finish" commands handle them automatically.
3400 * GDB now supports the token-splicing (##) and stringification (#)
3401 operators when expanding macros. It also supports variable-arity
3404 * GDB now supports inspecting extra signal information, exported by
3405 the new $_siginfo convenience variable. The feature is currently
3406 implemented on linux ARM, i386 and amd64.
3408 * GDB can now display the VFP floating point registers and NEON vector
3409 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3410 can provide these registers (requires Linux 2.6.30 or later). Remote
3411 and simulator targets may also provide them.
3413 * New remote packets
3416 Search memory for a sequence of bytes.
3419 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3420 operation over reliable transport links. Use of this packet is
3421 controlled by the `set remote noack-packet' command.
3424 Kill the process with the specified process ID. Use this in preference
3425 to `k' when multiprocess protocol extensions are supported.
3428 Obtains additional operating system information
3432 Read or write additional signal information.
3434 * Removed remote protocol undocumented extension
3436 An undocumented extension to the remote protocol's `S' stop reply
3437 packet that permited the stub to pass a process id was removed.
3438 Remote servers should use the `T' stop reply packet instead.
3440 * GDB now supports multiple function calling conventions according to the
3441 DWARF-2 DW_AT_calling_convention function attribute.
3443 * The SH target utilizes the aforementioned change to distinguish between gcc
3444 and Renesas calling convention. It also adds the new CLI commands
3445 `set/show sh calling-convention'.
3447 * GDB can now read compressed debug sections, as produced by GNU gold
3448 with the --compress-debug-sections=zlib flag.
3450 * 64-bit core files are now supported on AIX.
3452 * Thread switching is now supported on Tru64.
3454 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3455 which will be allocated using malloc later in program execution.
3457 * The qXfer:libraries:read remote procotol packet now allows passing a
3458 list of section offsets.
3460 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3461 conditions handling signals delivered during attach or thread creation
3462 have also been fixed.
3464 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3465 From the user's standpoint, all unqualified instances of True and False
3466 are treated as the standard definitions, regardless of context.
3468 * GDB now parses C++ symbol and type names more flexibly. For
3471 template<typename T> class C { };
3474 GDB will now correctly handle all of:
3476 ptype C<char const *>
3477 ptype C<char const*>
3478 ptype C<const char *>
3479 ptype C<const char*>
3481 * New features in the GDB remote stub, gdbserver
3483 - The "--wrapper" command-line argument tells gdbserver to use a
3484 wrapper program to launch programs for debugging.
3486 - On PowerPC and S/390 targets, it is now possible to use a single
3487 gdbserver executable to debug both 32-bit and 64-bit programs.
3488 (This requires gdbserver itself to be built as a 64-bit executable.)
3490 - gdbserver uses the new noack protocol mode for TCP connections to
3491 reduce communications latency, if also supported and enabled in GDB.
3493 - Support for the sparc64-linux-gnu target is now included in
3496 - The amd64-linux build of gdbserver now supports debugging both
3497 32-bit and 64-bit programs.
3499 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3500 now support hardware watchpoints, and will use them automatically
3505 GDB now has support for scripting using Python. Whether this is
3506 available is determined at configure time.
3508 New GDB commands can now be written in Python.
3510 * Ada tasking support
3512 Ada tasks can now be inspected in GDB. The following commands have
3516 Print the list of Ada tasks.
3518 Print detailed information about task number N.
3520 Print the task number of the current task.
3522 Switch the context of debugging to task number N.
3524 * Support for user-defined prefixed commands. The "define" command can
3525 add new commands to existing prefixes, e.g. "target".
3527 * Multi-inferior, multi-process debugging.
3529 GDB now has generalized support for multi-inferior debugging. See
3530 "Debugging Multiple Inferiors" in the manual for more information.
3531 Although availability still depends on target support, the command
3532 set is more uniform now. The GNU/Linux specific multi-forks support
3533 has been migrated to this new framework. This implied some user
3534 visible changes; see "New commands" and also "Removed commands"
3537 * Target descriptions can now describe the target OS ABI. See the
3538 "Target Description Format" section in the user manual for more
3541 * Target descriptions can now describe "compatible" architectures
3542 to indicate that the target can execute applications for a different
3543 architecture in addition to those for the main target architecture.
3544 See the "Target Description Format" section in the user manual for
3547 * Multi-architecture debugging.
3549 GDB now includes general supports for debugging applications on
3550 hybrid systems that use more than one single processor architecture
3551 at the same time. Each such hybrid architecture still requires
3552 specific support to be added. The only hybrid architecture supported
3553 in this version of GDB is the Cell Broadband Engine.
3555 * GDB now supports integrated debugging of Cell/B.E. applications that
3556 use both the PPU and SPU architectures. To enable support for hybrid
3557 Cell/B.E. debugging, you need to configure GDB to support both the
3558 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3559 --enable-targets configure option.
3561 * Non-stop mode debugging.
3563 For some targets, GDB now supports an optional mode of operation in
3564 which you can examine stopped threads while other threads continue
3565 to execute freely. This is referred to as non-stop mode, with the
3566 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3567 section in the user manual for more information.
3569 To be able to support remote non-stop debugging, a remote stub needs
3570 to implement the non-stop mode remote protocol extensions, as
3571 described in the "Remote Non-Stop" section of the user manual. The
3572 GDB remote stub, gdbserver, has been adjusted to support these
3573 extensions on linux targets.
3575 * New commands (for set/show, see "New options" below)
3577 catch syscall [NAME(S) | NUMBER(S)]
3578 Catch system calls. Arguments, which should be names of system
3579 calls or their numbers, mean catch only those syscalls. Without
3580 arguments, every syscall will be caught. When the inferior issues
3581 any of the specified syscalls, GDB will stop and announce the system
3582 call, both when it is called and when its call returns. This
3583 feature is currently available with a native GDB running on the
3584 Linux Kernel, under the following architectures: x86, x86_64,
3585 PowerPC and PowerPC64.
3587 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3589 Search memory for a sequence of bytes.
3591 maint set python print-stack
3592 maint show python print-stack
3593 Show a stack trace when an error is encountered in a Python script.
3596 Invoke CODE by passing it to the Python interpreter.
3601 These allow macros to be defined, undefined, and listed
3605 Show operating system information about processes.
3608 List the inferiors currently under GDB's control.
3611 Switch focus to inferior number NUM.
3614 Detach from inferior number NUM.
3617 Kill inferior number NUM.
3621 set spu stop-on-load
3622 show spu stop-on-load
3623 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3625 set spu auto-flush-cache
3626 show spu auto-flush-cache
3627 Control whether to automatically flush the software-managed cache
3628 during Cell/B.E. debugging.
3630 set sh calling-convention
3631 show sh calling-convention
3632 Control the calling convention used when calling SH target functions.
3635 show debug timestamp
3636 Control display of timestamps with GDB debugging output.
3638 set disassemble-next-line
3639 show disassemble-next-line
3640 Control display of disassembled source lines or instructions when
3643 set remote noack-packet
3644 show remote noack-packet
3645 Set/show the use of remote protocol QStartNoAckMode packet. See above
3646 under "New remote packets."
3648 set remote query-attached-packet
3649 show remote query-attached-packet
3650 Control use of remote protocol `qAttached' (query-attached) packet.
3652 set remote read-siginfo-object
3653 show remote read-siginfo-object
3654 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3657 set remote write-siginfo-object
3658 show remote write-siginfo-object
3659 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3662 set remote reverse-continue
3663 show remote reverse-continue
3664 Control use of remote protocol 'bc' (reverse-continue) packet.
3666 set remote reverse-step
3667 show remote reverse-step
3668 Control use of remote protocol 'bs' (reverse-step) packet.
3670 set displaced-stepping
3671 show displaced-stepping
3672 Control displaced stepping mode. Displaced stepping is a way to
3673 single-step over breakpoints without removing them from the debuggee.
3674 Also known as "out-of-line single-stepping".
3677 show debug displaced
3678 Control display of debugging info for displaced stepping.
3680 maint set internal-error
3681 maint show internal-error
3682 Control what GDB does when an internal error is detected.
3684 maint set internal-warning
3685 maint show internal-warning
3686 Control what GDB does when an internal warning is detected.
3691 Use a wrapper program to launch programs for debugging.
3693 set multiple-symbols (all|ask|cancel)
3694 show multiple-symbols
3695 The value of this variable can be changed to adjust the debugger behavior
3696 when an expression or a breakpoint location contains an ambiguous symbol
3697 name (an overloaded function name, for instance).
3699 set breakpoint always-inserted
3700 show breakpoint always-inserted
3701 Keep breakpoints always inserted in the target, as opposed to inserting
3702 them when resuming the target, and removing them when the target stops.
3703 This option can improve debugger performance on slow remote targets.
3705 set arm fallback-mode (arm|thumb|auto)
3706 show arm fallback-mode
3707 set arm force-mode (arm|thumb|auto)
3709 These commands control how ARM GDB determines whether instructions
3710 are ARM or Thumb. The default for both settings is auto, which uses
3711 the current CPSR value for instructions without symbols; previous
3712 versions of GDB behaved as if "set arm fallback-mode arm".
3714 set disable-randomization
3715 show disable-randomization
3716 Standalone programs run with the virtual address space randomization enabled
3717 by default on some platforms. This option keeps the addresses stable across
3718 multiple debugging sessions.
3722 Control whether other threads are stopped or not when some thread hits
3727 Requests that asynchronous execution is enabled in the target, if available.
3728 In this case, it's possible to resume target in the background, and interact
3729 with GDB while the target is running. "show target-async" displays the
3730 current state of asynchronous execution of the target.
3732 set target-wide-charset
3733 show target-wide-charset
3734 The target-wide-charset is the name of the character set that GDB
3735 uses when printing characters whose type is wchar_t.
3737 set tcp auto-retry (on|off)
3739 set tcp connect-timeout
3740 show tcp connect-timeout
3741 These commands allow GDB to retry failed TCP connections to a remote stub
3742 with a specified timeout period; this is useful if the stub is launched
3743 in parallel with GDB but may not be ready to accept connections immediately.
3745 set libthread-db-search-path
3746 show libthread-db-search-path
3747 Control list of directories which GDB will search for appropriate
3750 set schedule-multiple (on|off)
3751 show schedule-multiple
3752 Allow GDB to resume all threads of all processes or only threads of
3753 the current process.
3757 Use more aggressive caching for accesses to the stack. This improves
3758 performance of remote debugging (particularly backtraces) without
3759 affecting correctness.
3761 set interactive-mode (on|off|auto)
3762 show interactive-mode
3763 Control whether GDB runs in interactive mode (on) or not (off).
3764 When in interactive mode, GDB waits for the user to answer all
3765 queries. Otherwise, GDB does not wait and assumes the default
3766 answer. When set to auto (the default), GDB determines which
3767 mode to use based on the stdin settings.
3772 For program forks, this is replaced by the new more generic `info
3773 inferiors' command. To list checkpoints, you can still use the
3774 `info checkpoints' command, which was an alias for the `info forks'
3778 Replaced by the new `inferior' command. To switch between
3779 checkpoints, you can still use the `restart' command, which was an
3780 alias for the `fork' command.
3783 This is removed, since some targets don't have a notion of
3784 processes. To switch between processes, you can still use the
3785 `inferior' command using GDB's own inferior number.
3788 For program forks, this is replaced by the new more generic `kill
3789 inferior' command. To delete a checkpoint, you can still use the
3790 `delete checkpoint' command, which was an alias for the `delete
3794 For program forks, this is replaced by the new more generic `detach
3795 inferior' command. To detach a checkpoint, you can still use the
3796 `detach checkpoint' command, which was an alias for the `detach
3799 * New native configurations
3801 x86/x86_64 Darwin i[34567]86-*-darwin*
3803 x86_64 MinGW x86_64-*-mingw*
3807 Lattice Mico32 lm32-*
3808 x86 DICOS i[34567]86-*-dicos*
3809 x86_64 DICOS x86_64-*-dicos*
3812 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3813 (mingw32ce) debugging.
3819 These commands were actually not implemented on any target.
3821 *** Changes in GDB 6.8
3823 * New native configurations
3825 NetBSD/hppa hppa*-*netbsd*
3826 Xtensa GNU/Linux xtensa*-*-linux*
3830 NetBSD/hppa hppa*-*-netbsd*
3831 Xtensa GNU/Lunux xtensa*-*-linux*
3833 * Change in command line behavior -- corefiles vs. process ids.
3835 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3836 attaching to process NUMBER fails, GDB no longer attempts to open a
3837 core file named NUMBER. Attaching to a program using the -c option
3838 is no longer supported. Instead, use the '-p' or '--pid' options.
3840 * GDB can now be built as a native debugger for debugging Windows x86
3841 (mingw32) Portable Executable (PE) programs.
3843 * Pending breakpoints no longer change their number when their address
3846 * GDB now supports breakpoints with multiple locations,
3847 including breakpoints on C++ constructors, inside C++ templates,
3848 and in inlined functions.
3850 * GDB's ability to debug optimized code has been improved. GDB more
3851 accurately identifies function bodies and lexical blocks that occupy
3852 more than one contiguous range of addresses.
3854 * Target descriptions can now describe registers for PowerPC.
3856 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3857 registers on PowerPC targets.
3859 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3860 targets even when the libthread_db library is not available.
3862 * The GDB remote stub, gdbserver, now supports the new file transfer
3863 commands (remote put, remote get, and remote delete).
3865 * The GDB remote stub, gdbserver, now supports run and attach in
3866 extended-remote mode.
3868 * hppa*64*-*-hpux11* target broken
3869 The debugger is unable to start a program and fails with the following
3870 error: "Error trying to get information about dynamic linker".
3871 The gdb-6.7 release is also affected.
3873 * GDB now supports the --enable-targets= configure option to allow
3874 building a single GDB executable that supports multiple remote
3875 target architectures.
3877 * GDB now supports debugging C and C++ programs which use the
3878 Decimal Floating Point extension. In addition, the PowerPC target
3879 now has a set of pseudo-registers to inspect decimal float values
3880 stored in two consecutive float registers.
3882 * The -break-insert MI command can optionally create pending
3885 * Improved support for debugging Ada
3886 Many improvements to the Ada language support have been made. These
3888 - Better support for Ada2005 interface types
3889 - Improved handling of arrays and slices in general
3890 - Better support for Taft-amendment types
3891 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3893 - Improved command completion in Ada
3896 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3901 set print frame-arguments (all|scalars|none)
3902 show print frame-arguments
3903 The value of this variable can be changed to control which argument
3904 values should be printed by the debugger when displaying a frame.
3909 Transfer files to and from a remote target, and delete remote files.
3916 Transfer files to and from a remote target, and delete remote files.
3918 * New remote packets
3925 Open, close, read, write, and delete files on the remote system.
3928 Attach to an existing process on the remote system, in extended-remote
3932 Run a new process on the remote system, in extended-remote mode.
3934 *** Changes in GDB 6.7
3936 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3937 bfd, libiberty and opcodes, as revealed by static analysis donated by
3938 Coverity, Inc. (http://scan.coverity.com).
3940 * When looking up multiply-defined global symbols, GDB will now prefer the
3941 symbol definition in the current shared library if it was built using the
3942 -Bsymbolic linker option.
3944 * When the Text User Interface (TUI) is not configured, GDB will now
3945 recognize the -tui command-line option and print a message that the TUI
3948 * The GDB remote stub, gdbserver, now has lower overhead for high
3949 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3951 * GDB for MIPS targets now autodetects whether a remote target provides
3952 32-bit or 64-bit register values.
3954 * Support for C++ member pointers has been improved.
3956 * GDB now understands XML target descriptions, which specify the
3957 target's overall architecture. GDB can read a description from
3958 a local file or over the remote serial protocol.
3960 * Vectors of single-byte data use a new integer type which is not
3961 automatically displayed as character or string data.
3963 * The /s format now works with the print command. It displays
3964 arrays of single-byte integers and pointers to single-byte integers
3967 * Target descriptions can now describe target-specific registers,
3968 for architectures which have implemented the support (currently
3969 only ARM, M68K, and MIPS).
3971 * GDB and the GDB remote stub, gdbserver, now support the XScale
3974 * The GDB remote stub, gdbserver, has been updated to support
3975 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3976 has been rewritten to use the standard GDB remote protocol.
3978 * GDB can now step into C++ functions which are called through thunks.
3980 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3982 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3983 layout. It also supports a TextSeg= and DataSeg= response when only
3984 segment base addresses (rather than offsets) are available.
3986 * The /i format now outputs any trailing branch delay slot instructions
3987 immediately following the last instruction within the count specified.
3989 * The GDB remote protocol "T" stop reply packet now supports a
3990 "library" response. Combined with the new "qXfer:libraries:read"
3991 packet, this response allows GDB to debug shared libraries on targets
3992 where the operating system manages the list of loaded libraries (e.g.
3993 Windows and SymbianOS).
3995 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3996 (DLLs) on Windows and Windows CE targets.
3998 * GDB now supports a faster verification that a .debug file matches its binary
3999 according to its build-id signature, if the signature is present.
4005 Enable or disable hardware flow control (RTS/CTS) on the serial port
4006 when debugging using remote targets.
4008 set mem inaccessible-by-default
4009 show mem inaccessible-by-default
4010 If the target supplies a memory map, for instance via the remote
4011 protocol's "qXfer:memory-map:read" packet, setting this variable
4012 prevents GDB from accessing memory outside the memory map. This
4013 is useful for targets with memory mapped registers or which react
4014 badly to accesses of unmapped address space.
4016 set breakpoint auto-hw
4017 show breakpoint auto-hw
4018 If the target supplies a memory map, for instance via the remote
4019 protocol's "qXfer:memory-map:read" packet, setting this variable
4020 lets GDB use hardware breakpoints automatically for memory regions
4021 where it can not use software breakpoints. This covers both the
4022 "break" command and internal breakpoints used for other commands
4023 including "next" and "finish".
4026 catch exception unhandled
4027 Stop the program execution when Ada exceptions are raised.
4030 Stop the program execution when an Ada assertion failed.
4034 Set an alternate system root for target files. This is a more
4035 general version of "set solib-absolute-prefix", which is now
4036 an alias to "set sysroot".
4039 Provide extended SPU facility status information. This set of
4040 commands is available only when debugging the Cell/B.E. SPU
4043 * New native configurations
4045 OpenBSD/sh sh*-*openbsd*
4048 unset tdesc filename
4050 Use the specified local file as an XML target description, and do
4051 not query the target for its built-in description.
4055 OpenBSD/sh sh*-*-openbsd*
4056 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4057 Toshiba Media Processor mep-elf
4059 * New remote packets
4062 Ignore the specified signals; pass them directly to the debugged program
4063 without stopping other threads or reporting them to GDB.
4065 qXfer:features:read:
4066 Read an XML target description from the target, which describes its
4071 Read or write contents of an spufs file on the target system. These
4072 packets are available only on the Cell/B.E. SPU architecture.
4074 qXfer:libraries:read:
4075 Report the loaded shared libraries. Combined with new "T" packet
4076 response, this packet allows GDB to debug shared libraries on
4077 targets where the operating system manages the list of loaded
4078 libraries (e.g. Windows and SymbianOS).
4082 Support for these obsolete configurations has been removed.
4090 i[34567]86-*-lynxos*
4091 i[34567]86-*-netware*
4092 i[34567]86-*-sco3.2v5*
4093 i[34567]86-*-sco3.2v4*
4095 i[34567]86-*-sysv4.2*
4098 i[34567]86-*-unixware2*
4099 i[34567]86-*-unixware*
4108 * Other removed features
4115 Various m68k-only ROM monitors.
4122 Various Renesas ROM monitors and debugging interfaces for SH and
4127 Support for a Macraigor serial interface to on-chip debugging.
4128 GDB does not directly support the newer parallel or USB
4133 A debug information format. The predecessor to DWARF 2 and
4134 DWARF 3, which are still supported.
4136 Support for the HP aCC compiler on HP-UX/PA-RISC
4138 SOM-encapsulated symbolic debugging information, automatic
4139 invocation of pxdb, and the aCC custom C++ ABI. This does not
4140 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4141 with aCC can still be debugged on an assembly level.
4143 MIPS ".pdr" sections
4145 A MIPS-specific format used to describe stack frame layout
4146 in debugging information.
4150 GDB could work with an older version of Guile to debug
4151 the interpreter and Scheme programs running in it.
4153 set mips stack-arg-size
4154 set mips saved-gpreg-size
4156 Use "set mips abi" to control parameter passing for MIPS.
4158 *** Changes in GDB 6.6
4163 Cell Broadband Engine SPU spu-elf
4165 * GDB can now be configured as a cross-debugger targeting native Windows
4166 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4167 running on a Windows system over TCP/IP to debug Windows programs.
4169 * The GDB remote stub, gdbserver, has been updated to support Windows and
4170 Cygwin debugging. Both single-threaded and multi-threaded programs are
4173 * The "set trust-readonly-sections" command works again. This command was
4174 broken in GDB 6.3, 6.4, and 6.5.
4176 * The "load" command now supports writing to flash memory, if the remote
4177 stub provides the required support.
4179 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4180 longer requires symbolic debug information (e.g. DWARF-2).
4185 unset substitute-path
4186 show substitute-path
4187 Manage a list of substitution rules that GDB uses to rewrite the name
4188 of the directories where the sources are located. This can be useful
4189 for instance when the sources were moved to a different location
4190 between compilation and debugging.
4194 Print each CLI command as it is executed. Each command is prefixed with
4195 a number of `+' symbols representing the nesting depth.
4196 The source command now has a `-v' option to enable the same feature.
4200 The ARM Demon monitor support (RDP protocol, "target rdp").
4202 Kernel Object Display, an embedded debugging feature which only worked with
4203 an obsolete version of Cisco IOS.
4205 The 'set download-write-size' and 'show download-write-size' commands.
4207 * New remote packets
4210 Tell a stub about GDB client features, and request remote target features.
4211 The first feature implemented is PacketSize, which allows the target to
4212 specify the size of packets it can handle - to minimize the number of
4213 packets required and improve performance when connected to a remote
4217 Fetch an OS auxilliary vector from the remote stub. This packet is a
4218 more efficient replacement for qPart:auxv:read.
4220 qXfer:memory-map:read:
4221 Fetch a memory map from the remote stub, including information about
4222 RAM, ROM, and flash memory devices.
4227 Erase and program a flash memory device.
4229 * Removed remote packets
4232 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4233 used it, and only gdbserver implemented it.
4235 *** Changes in GDB 6.5
4239 Renesas M32C/M16C m32c-elf
4241 Morpho Technologies ms1 ms1-elf
4245 init-if-undefined Initialize a convenience variable, but
4246 only if it doesn't already have a value.
4248 The following commands are presently only implemented for native GNU/Linux:
4250 checkpoint Save a snapshot of the program state.
4252 restart <n> Return the program state to a
4253 previously saved state.
4255 info checkpoints List currently saved checkpoints.
4257 delete-checkpoint <n> Delete a previously saved checkpoint.
4259 set|show detach-on-fork Tell gdb whether to detach from a newly
4260 forked process, or to keep debugging it.
4262 info forks List forks of the user program that
4263 are available to be debugged.
4265 fork <n> Switch to debugging one of several
4266 forks of the user program that are
4267 available to be debugged.
4269 delete-fork <n> Delete a fork from the list of forks
4270 that are available to be debugged (and
4271 kill the forked process).
4273 detach-fork <n> Delete a fork from the list of forks
4274 that are available to be debugged (and
4275 allow the process to continue).
4279 Morpho Technologies ms2 ms1-elf
4281 * Improved Windows host support
4283 GDB now builds as a cross debugger hosted on i686-mingw32, including
4284 native console support, and remote communications using either
4285 network sockets or serial ports.
4287 * Improved Modula-2 language support
4289 GDB can now print most types in the Modula-2 syntax. This includes:
4290 basic types, set types, record types, enumerated types, range types,
4291 pointer types and ARRAY types. Procedure var parameters are correctly
4292 printed and hexadecimal addresses and character constants are also
4293 written in the Modula-2 syntax. Best results can be obtained by using
4294 GNU Modula-2 together with the -gdwarf-2 command line option.
4298 The ARM rdi-share module.
4300 The Netware NLM debug server.
4302 *** Changes in GDB 6.4
4304 * New native configurations
4306 OpenBSD/arm arm*-*-openbsd*
4307 OpenBSD/mips64 mips64-*-openbsd*
4311 Morpho Technologies ms1 ms1-elf
4313 * New command line options
4315 --batch-silent As for --batch, but totally silent.
4316 --return-child-result The debugger will exist with the same value
4317 the child (debugged) program exited with.
4318 --eval-command COMMAND, -ex COMMAND
4319 Execute a single GDB CLI command. This may be
4320 specified multiple times and in conjunction
4321 with the --command (-x) option.
4323 * Deprecated commands removed
4325 The following commands, that were deprecated in 2000, have been
4329 set|show arm disassembly-flavor set|show arm disassembler
4330 othernames set arm disassembler
4331 set|show remotedebug set|show debug remote
4332 set|show archdebug set|show debug arch
4333 set|show eventdebug set|show debug event
4336 * New BSD user-level threads support
4338 It is now possible to debug programs using the user-level threads
4339 library on OpenBSD and FreeBSD. Currently supported (target)
4342 FreeBSD/amd64 x86_64-*-freebsd*
4343 FreeBSD/i386 i386-*-freebsd*
4344 OpenBSD/i386 i386-*-openbsd*
4346 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4347 are not yet supported.
4349 * New support for Matsushita MN10300 w/sim added
4350 (Work in progress). mn10300-elf.
4352 * REMOVED configurations and files
4354 VxWorks and the XDR protocol *-*-vxworks
4355 Motorola MCORE mcore-*-*
4356 National Semiconductor NS32000 ns32k-*-*
4358 * New "set print array-indexes" command
4360 After turning this setting "on", GDB prints the index of each element
4361 when displaying arrays. The default is "off" to preserve the previous
4364 * VAX floating point support
4366 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4368 * User-defined command support
4370 In addition to using $arg0..$arg9 for argument passing, it is now possible
4371 to use $argc to determine now many arguments have been passed. See the
4372 section on user-defined commands in the user manual for more information.
4374 *** Changes in GDB 6.3:
4376 * New command line option
4378 GDB now accepts -l followed by a number to set the timeout for remote
4381 * GDB works with GCC -feliminate-dwarf2-dups
4383 GDB now supports a more compact representation of DWARF-2 debug
4384 information using DW_FORM_ref_addr references. These are produced
4385 by GCC with the option -feliminate-dwarf2-dups and also by some
4386 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4387 to use -feliminate-dwarf2-dups.
4389 * Internationalization
4391 When supported by the host system, GDB will be built with
4392 internationalization (libintl). The task of marking up the sources is
4393 continued, we're looking forward to our first translation.
4397 Initial support for debugging programs compiled with the GNAT
4398 implementation of the Ada programming language has been integrated
4399 into GDB. In this release, support is limited to expression evaluation.
4401 * New native configurations
4403 GNU/Linux/m32r m32r-*-linux-gnu
4407 GDB's remote protocol now includes support for the 'p' packet. This
4408 packet is used to fetch individual registers from a remote inferior.
4410 * END-OF-LIFE registers[] compatibility module
4412 GDB's internal register infrastructure has been completely rewritten.
4413 The new infrastructure making possible the implementation of key new
4414 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4417 GDB 6.3 will be the last release to include the the registers[]
4418 compatibility module that allowed out-of-date configurations to
4419 continue to work. This change directly impacts the following
4429 powerpc bdm protocol
4431 Unless there is activity to revive these configurations, they will be
4432 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4434 * OBSOLETE configurations and files
4436 Configurations that have been declared obsolete in this release have
4437 been commented out. Unless there is activity to revive these
4438 configurations, the next release of GDB will have their sources
4439 permanently REMOVED.
4448 *** Changes in GDB 6.2.1:
4450 * MIPS `break main; run' gave an heuristic-fence-post warning
4452 When attempting to run even a simple program, a warning about
4453 heuristic-fence-post being hit would be reported. This problem has
4456 * MIPS IRIX 'long double' crashed GDB
4458 When examining a long double variable, GDB would get a segmentation
4459 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4460 IRIX long double values).
4464 A bug in the VAX stack code was causing problems with the "next"
4465 command. This problem has been fixed.
4467 *** Changes in GDB 6.2:
4469 * Fix for ``many threads''
4471 On GNU/Linux systems that use the NPTL threads library, a program
4472 rapidly creating and deleting threads would confuse GDB leading to the
4475 ptrace: No such process.
4476 thread_db_get_info: cannot get thread info: generic error
4478 This problem has been fixed.
4480 * "-async" and "-noasync" options removed.
4482 Support for the broken "-noasync" option has been removed (it caused
4485 * New ``start'' command.
4487 This command runs the program until the begining of the main procedure.
4489 * New BSD Kernel Data Access Library (libkvm) interface
4491 Using ``target kvm'' it is now possible to debug kernel core dumps and
4492 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4493 platforms. Currently supported (native-only) configurations are:
4495 FreeBSD/amd64 x86_64-*-freebsd*
4496 FreeBSD/i386 i?86-*-freebsd*
4497 NetBSD/i386 i?86-*-netbsd*
4498 NetBSD/m68k m68*-*-netbsd*
4499 NetBSD/sparc sparc-*-netbsd*
4500 OpenBSD/amd64 x86_64-*-openbsd*
4501 OpenBSD/i386 i?86-*-openbsd*
4502 OpenBSD/m68k m68*-openbsd*
4503 OpenBSD/sparc sparc-*-openbsd*
4505 * Signal trampoline code overhauled
4507 Many generic problems with GDB's signal handling code have been fixed.
4508 These include: backtraces through non-contiguous stacks; recognition
4509 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4510 call; backtrace through a signal trampoline; step into and out of
4511 signal handlers; and single-stepping in the signal trampoline.
4513 Please note that kernel bugs are a limiting factor here. These
4514 features have been shown to work on an s390 GNU/Linux system that
4515 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4517 * Cygwin support for DWARF 2 added.
4519 * New native configurations
4521 GNU/Linux/hppa hppa*-*-linux*
4522 OpenBSD/hppa hppa*-*-openbsd*
4523 OpenBSD/m68k m68*-*-openbsd*
4524 OpenBSD/m88k m88*-*-openbsd*
4525 OpenBSD/powerpc powerpc-*-openbsd*
4526 NetBSD/vax vax-*-netbsd*
4527 OpenBSD/vax vax-*-openbsd*
4529 * END-OF-LIFE frame compatibility module
4531 GDB's internal frame infrastructure has been completely rewritten.
4532 The new infrastructure making it possible to support key new features
4533 including DWARF 2 Call Frame Information. To aid in the task of
4534 migrating old configurations to this new infrastructure, a
4535 compatibility module, that allowed old configurations to continue to
4536 work, was also included.
4538 GDB 6.2 will be the last release to include this frame compatibility
4539 module. This change directly impacts the following configurations:
4549 Unless there is activity to revive these configurations, they will be
4550 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4552 * REMOVED configurations and files
4554 Sun 3, running SunOS 3 m68*-*-sunos3*
4555 Sun 3, running SunOS 4 m68*-*-sunos4*
4556 Sun 2, running SunOS 3 m68000-*-sunos3*
4557 Sun 2, running SunOS 4 m68000-*-sunos4*
4558 Motorola 680x0 running LynxOS m68*-*-lynxos*
4559 AT&T 3b1/Unix pc m68*-att-*
4560 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4561 decstation mips-dec-* mips-little-*
4562 riscos mips-*-riscos* mips-*-sysv*
4563 sonymips mips-sony-*
4564 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4566 *** Changes in GDB 6.1.1:
4568 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4570 The TUI (Text-mode User Interface) is now built as part of a default
4571 GDB configuration. It is enabled by either selecting the TUI with the
4572 command line option "-i=tui" or by running the separate "gdbtui"
4573 program. For more information on the TUI, see the manual "Debugging
4576 * Pending breakpoint support (also included in GDB 6.1)
4578 Support has been added to allow you to specify breakpoints in shared
4579 libraries that have not yet been loaded. If a breakpoint location
4580 cannot be found, and the "breakpoint pending" option is set to auto,
4581 GDB queries you if you wish to make the breakpoint pending on a future
4582 shared-library load. If and when GDB resolves the breakpoint symbol,
4583 the pending breakpoint is removed as one or more regular breakpoints
4586 Pending breakpoints are very useful for GCJ Java debugging.
4588 * Fixed ISO-C build problems
4590 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4591 non ISO-C code that stopped them being built using a more strict ISO-C
4592 compiler (e.g., IBM's C compiler).
4594 * Fixed build problem on IRIX 5
4596 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4597 wasn't able to compile compile on an IRIX 5 system.
4599 * Added execute permission to gdb/gdbserver/configure
4601 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4602 permission. This bug would cause configure to fail on a number of
4603 systems (Solaris, IRIX). Ref: server/519.
4605 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4607 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4608 has been updated to use constant array sizes.
4610 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4612 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4613 its generated DWARF Call Frame Info. This encoding was causing GDB to
4614 panic, that panic has been fixed. Ref: gdb/1628.
4616 * Fixed a problem when examining parameters in shared library code.
4618 When examining parameters in optimized shared library code generated
4619 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4620 not available''. GDB now correctly displays the variable's value.
4622 *** Changes in GDB 6.1:
4624 * Removed --with-mmalloc
4626 Support for the mmalloc memory manager has been removed, as it
4627 conflicted with the internal gdb byte cache.
4629 * Changes in AMD64 configurations
4631 The AMD64 target now includes the %cs and %ss registers. As a result
4632 the AMD64 remote protocol has changed; this affects the floating-point
4633 and SSE registers. If you rely on those registers for your debugging,
4634 you should upgrade gdbserver on the remote side.
4636 * Revised SPARC target
4638 The SPARC target has been completely revised, incorporating the
4639 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4640 support for LynxOS and SunOS 4 has been dropped. Calling functions
4641 from within GDB on operating systems with a non-executable stack
4642 (Solaris, OpenBSD) now works.
4646 GDB has a new C++ demangler which does a better job on the mangled
4647 names generated by current versions of g++. It also runs faster, so
4648 with this and other changes gdb should now start faster on large C++
4651 * DWARF 2 Location Expressions
4653 GDB support for location expressions has been extended to support function
4654 arguments and frame bases. Older versions of GDB could crash when they
4657 * C++ nested types and namespaces
4659 GDB's support for nested types and namespaces in C++ has been
4660 improved, especially if you use the DWARF 2 debugging format. (This
4661 is the default for recent versions of GCC on most platforms.)
4662 Specifically, if you have a class "Inner" defined within a class or
4663 namespace "Outer", then GDB realizes that the class's name is
4664 "Outer::Inner", not simply "Inner". This should greatly reduce the
4665 frequency of complaints about not finding RTTI symbols. In addition,
4666 if you are stopped at inside of a function defined within a namespace,
4667 GDB modifies its name lookup accordingly.
4669 * New native configurations
4671 NetBSD/amd64 x86_64-*-netbsd*
4672 OpenBSD/amd64 x86_64-*-openbsd*
4673 OpenBSD/alpha alpha*-*-openbsd*
4674 OpenBSD/sparc sparc-*-openbsd*
4675 OpenBSD/sparc64 sparc64-*-openbsd*
4677 * New debugging protocols
4679 M32R with SDI protocol m32r-*-elf*
4681 * "set prompt-escape-char" command deleted.
4683 The command "set prompt-escape-char" has been deleted. This command,
4684 and its very obscure effet on GDB's prompt, was never documented,
4685 tested, nor mentioned in the NEWS file.
4687 * OBSOLETE configurations and files
4689 Configurations that have been declared obsolete in this release have
4690 been commented out. Unless there is activity to revive these
4691 configurations, the next release of GDB will have their sources
4692 permanently REMOVED.
4694 Sun 3, running SunOS 3 m68*-*-sunos3*
4695 Sun 3, running SunOS 4 m68*-*-sunos4*
4696 Sun 2, running SunOS 3 m68000-*-sunos3*
4697 Sun 2, running SunOS 4 m68000-*-sunos4*
4698 Motorola 680x0 running LynxOS m68*-*-lynxos*
4699 AT&T 3b1/Unix pc m68*-att-*
4700 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4701 decstation mips-dec-* mips-little-*
4702 riscos mips-*-riscos* mips-*-sysv*
4703 sonymips mips-sony-*
4704 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4706 * REMOVED configurations and files
4708 SGI Irix-4.x mips-sgi-irix4 or iris4
4709 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4710 Z8000 simulator z8k-zilog-none or z8ksim
4711 Matsushita MN10200 w/simulator mn10200-*-*
4712 H8/500 simulator h8500-hitachi-hms or h8500hms
4713 HP/PA running BSD hppa*-*-bsd*
4714 HP/PA running OSF/1 hppa*-*-osf*
4715 HP/PA Pro target hppa*-*-pro*
4716 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4717 386BSD i[3456]86-*-bsd*
4718 Sequent family i[3456]86-sequent-sysv4*
4719 i[3456]86-sequent-sysv*
4720 i[3456]86-sequent-bsd*
4721 SPARC running LynxOS sparc-*-lynxos*
4722 SPARC running SunOS 4 sparc-*-sunos4*
4723 Tsqware Sparclet sparclet-*-*
4724 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4726 *** Changes in GDB 6.0:
4730 Support for debugging the Objective-C programming language has been
4731 integrated into GDB.
4733 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4735 DWARF 2's Call Frame Information makes available compiler generated
4736 information that more exactly describes the program's run-time stack.
4737 By using this information, GDB is able to provide more robust stack
4740 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4741 have been updated to use a new backtrace mechanism which includes
4742 DWARF 2 CFI support.
4746 GDB's remote protocol has been extended to include support for hosted
4747 file I/O (where the remote target uses GDB's file system). See GDB's
4748 remote protocol documentation for details.
4750 * All targets using the new architecture framework.
4752 All of GDB's targets have been updated to use the new internal
4753 architecture framework. The way is now open for future GDB releases
4754 to include cross-architecture native debugging support (i386 on amd64,
4757 * GNU/Linux's Thread Local Storage (TLS)
4759 GDB now includes support for for the GNU/Linux implementation of
4760 per-thread variables.
4762 * GNU/Linux's Native POSIX Thread Library (NPTL)
4764 GDB's thread code has been updated to work with either the new
4765 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4767 * Separate debug info.
4769 GDB, in conjunction with BINUTILS, now supports a mechanism for
4770 automatically loading debug information from a separate file. Instead
4771 of shipping full debug and non-debug versions of system libraries,
4772 system integrators can now instead ship just the stripped libraries
4773 and optional debug files.
4775 * DWARF 2 Location Expressions
4777 DWARF 2 Location Expressions allow the compiler to more completely
4778 describe the location of variables (even in optimized code) to the
4781 GDB now includes preliminary support for location expressions (support
4782 for DW_OP_piece is still missing).
4786 A number of long standing bugs that caused GDB to die while starting a
4787 Java application have been fixed. GDB's Java support is now
4788 considered "useable".
4790 * GNU/Linux support for fork, vfork, and exec.
4792 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4793 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4796 * GDB supports logging output to a file
4798 There are two new commands, "set logging" and "show logging", which can be
4799 used to capture GDB's output to a file.
4801 * The meaning of "detach" has changed for gdbserver
4803 The "detach" command will now resume the application, as documented. To
4804 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4807 * d10v, m68hc11 `regs' command deprecated
4809 The `info registers' command has been updated so that it displays the
4810 registers using a format identical to the old `regs' command.
4814 A new command, "maint set profile on/off", has been added. This command can
4815 be used to enable or disable profiling while running GDB, to profile a
4816 session or a set of commands. In addition there is a new configure switch,
4817 "--enable-profiling", which will cause GDB to be compiled with profiling
4818 data, for more informative profiling results.
4820 * Default MI syntax changed to "mi2".
4822 The default MI (machine interface) syntax, enabled by the command line
4823 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4824 "mi1", can be enabled by specifying the option "-i=mi1".
4826 Support for the original "mi0" syntax (included in GDB 5.0) has been
4829 Fix for gdb/192: removed extraneous space when displaying frame level.
4830 Fix for gdb/672: update changelist is now output in mi list format.
4831 Fix for gdb/702: a -var-assign that updates the value now shows up
4832 in a subsequent -var-update.
4834 * New native configurations.
4836 FreeBSD/amd64 x86_64-*-freebsd*
4838 * Multi-arched targets.
4840 HP/PA HPUX11 hppa*-*-hpux*
4841 Renesas M32R/D w/simulator m32r-*-elf*
4843 * OBSOLETE configurations and files
4845 Configurations that have been declared obsolete in this release have
4846 been commented out. Unless there is activity to revive these
4847 configurations, the next release of GDB will have their sources
4848 permanently REMOVED.
4850 Z8000 simulator z8k-zilog-none or z8ksim
4851 Matsushita MN10200 w/simulator mn10200-*-*
4852 H8/500 simulator h8500-hitachi-hms or h8500hms
4853 HP/PA running BSD hppa*-*-bsd*
4854 HP/PA running OSF/1 hppa*-*-osf*
4855 HP/PA Pro target hppa*-*-pro*
4856 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4857 Sequent family i[3456]86-sequent-sysv4*
4858 i[3456]86-sequent-sysv*
4859 i[3456]86-sequent-bsd*
4860 Tsqware Sparclet sparclet-*-*
4861 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4863 * REMOVED configurations and files
4866 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4867 IBM AIX PS/2 i[3456]86-*-aix
4868 i386 running Mach 3.0 i[3456]86-*-mach3*
4869 i386 running Mach i[3456]86-*-mach*
4870 i386 running OSF/1 i[3456]86-*osf1mk*
4871 HP/Apollo 68k Family m68*-apollo*-sysv*,
4873 m68*-hp-bsd*, m68*-hp-hpux*
4874 Argonaut Risc Chip (ARC) arc-*-*
4875 Mitsubishi D30V d30v-*-*
4876 Fujitsu FR30 fr30-*-elf*
4877 OS/9000 i[34]86-*-os9k
4878 I960 with MON960 i960-*-coff
4880 * MIPS $fp behavior changed
4882 The convenience variable $fp, for the MIPS, now consistently returns
4883 the address of the current frame's base. Previously, depending on the
4884 context, $fp could refer to either $sp or the current frame's base
4885 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4886 The GNU Source-Level Debugger''.
4888 *** Changes in GDB 5.3:
4890 * GNU/Linux shared library multi-threaded performance improved.
4892 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4893 `/proc', in preference to `ptrace' for memory reads. This may result
4894 in an improvement in the start-up time of multi-threaded, shared
4895 library applications when run under GDB. One GDB user writes: ``loads
4896 shared libs like mad''.
4898 * ``gdbserver'' now supports multi-threaded applications on some targets
4900 Support for debugging multi-threaded applications which use
4901 the GNU/Linux LinuxThreads package has been added for
4902 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4903 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4905 * GDB now supports C/C++ preprocessor macros.
4907 GDB now expands preprocessor macro invocations in C/C++ expressions,
4908 and provides various commands for showing macro definitions and how
4911 The new command `macro expand EXPRESSION' expands any macro
4912 invocations in expression, and shows the result.
4914 The new command `show macro MACRO-NAME' shows the definition of the
4915 macro named MACRO-NAME, and where it was defined.
4917 Most compilers don't include information about macros in the debugging
4918 information by default. In GCC 3.1, for example, you need to compile
4919 your program with the options `-gdwarf-2 -g3'. If the macro
4920 information is present in the executable, GDB will read it.
4922 * Multi-arched targets.
4924 DEC Alpha (partial) alpha*-*-*
4925 DEC VAX (partial) vax-*-*
4927 National Semiconductor NS32000 (partial) ns32k-*-*
4928 Motorola 68000 (partial) m68k-*-*
4929 Motorola MCORE mcore-*-*
4933 Fujitsu FRV architecture added by Red Hat frv*-*-*
4936 * New native configurations
4938 Alpha NetBSD alpha*-*-netbsd*
4939 SH NetBSD sh*-*-netbsdelf*
4940 MIPS NetBSD mips*-*-netbsd*
4941 UltraSPARC NetBSD sparc64-*-netbsd*
4943 * OBSOLETE configurations and files
4945 Configurations that have been declared obsolete in this release have
4946 been commented out. Unless there is activity to revive these
4947 configurations, the next release of GDB will have their sources
4948 permanently REMOVED.
4950 Mitsubishi D30V d30v-*-*
4951 OS/9000 i[34]86-*-os9k
4952 IBM AIX PS/2 i[3456]86-*-aix
4953 Fujitsu FR30 fr30-*-elf*
4954 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4955 Argonaut Risc Chip (ARC) arc-*-*
4956 i386 running Mach 3.0 i[3456]86-*-mach3*
4957 i386 running Mach i[3456]86-*-mach*
4958 i386 running OSF/1 i[3456]86-*osf1mk*
4959 HP/Apollo 68k Family m68*-apollo*-sysv*,
4961 m68*-hp-bsd*, m68*-hp-hpux*
4962 I960 with MON960 i960-*-coff
4964 * OBSOLETE languages
4966 CHILL, a Pascal like language used by telecommunications companies.
4968 * REMOVED configurations and files
4970 AMD 29k family via UDI a29k-amd-udi, udi29k
4971 A29K VxWorks a29k-*-vxworks
4972 AMD 29000 embedded, using EBMON a29k-none-none
4973 AMD 29000 embedded with COFF a29k-none-coff
4974 AMD 29000 embedded with a.out a29k-none-aout
4976 testsuite/gdb.hp/gdb.threads-hp/ directory
4978 * New command "set max-user-call-depth <nnn>"
4980 This command allows the user to limit the call depth of user-defined
4981 commands. The default is 1024.
4983 * Changes in FreeBSD/i386 native debugging.
4985 Support for the "generate-core-file" has been added.
4987 * New commands "dump", "append", and "restore".
4989 These commands allow data to be copied from target memory
4990 to a bfd-format or binary file (dump and append), and back
4991 from a file into memory (restore).
4993 * Improved "next/step" support on multi-processor Alpha Tru64.
4995 The previous single-step mechanism could cause unpredictable problems,
4996 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4997 of a software single-step mechanism prevents this.
4999 *** Changes in GDB 5.2.1:
5007 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5008 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5009 Fix, by Joel Brobecker imported from mainline.
5011 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5012 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5013 Fix, by Fred Fish, imported from mainline.
5015 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5016 Surprisingly enough, it works now.
5017 By Michal Ludvig, imported from mainline.
5019 i386 hardware watchpoint support:
5020 avoid misses on second run for some targets.
5021 By Pierre Muller, imported from mainline.
5023 *** Changes in GDB 5.2:
5025 * New command "set trust-readonly-sections on[off]".
5027 This command is a hint that tells gdb that read-only sections
5028 really are read-only (ie. that their contents will not change).
5029 In this mode, gdb will go to the object file rather than the
5030 target to read memory from read-only sections (such as ".text").
5031 This can be a significant performance improvement on some
5032 (notably embedded) targets.
5034 * New command "generate-core-file" (or "gcore").
5036 This new gdb command allows the user to drop a core file of the child
5037 process state at any time. So far it's been implemented only for
5038 GNU/Linux and Solaris, but should be relatively easily ported to other
5039 hosts. Argument is core file name (defaults to core.<pid>).
5041 * New command line option
5043 GDB now accepts --pid or -p followed by a process id.
5045 * Change in command line behavior -- corefiles vs. process ids.
5047 There is a subtle behavior in the way in which GDB handles
5048 command line arguments. The first non-flag argument is always
5049 a program to debug, but the second non-flag argument may either
5050 be a corefile or a process id. Previously, GDB would attempt to
5051 open the second argument as a corefile, and if that failed, would
5052 issue a superfluous error message and then attempt to attach it as
5053 a process. Now, if the second argument begins with a non-digit,
5054 it will be treated as a corefile. If it begins with a digit,
5055 GDB will attempt to attach it as a process, and if no such process
5056 is found, will then attempt to open it as a corefile.
5058 * Changes in ARM configurations.
5060 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5061 configuration is fully multi-arch.
5063 * New native configurations
5065 ARM NetBSD arm*-*-netbsd*
5066 x86 OpenBSD i[3456]86-*-openbsd*
5067 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5068 Sparc64 running FreeBSD sparc64-*-freebsd*
5072 Sanyo XStormy16 xstormy16-elf
5074 * OBSOLETE configurations and files
5076 Configurations that have been declared obsolete in this release have
5077 been commented out. Unless there is activity to revive these
5078 configurations, the next release of GDB will have their sources
5079 permanently REMOVED.
5081 AMD 29k family via UDI a29k-amd-udi, udi29k
5082 A29K VxWorks a29k-*-vxworks
5083 AMD 29000 embedded, using EBMON a29k-none-none
5084 AMD 29000 embedded with COFF a29k-none-coff
5085 AMD 29000 embedded with a.out a29k-none-aout
5087 testsuite/gdb.hp/gdb.threads-hp/ directory
5089 * REMOVED configurations and files
5091 TI TMS320C80 tic80-*-*
5093 PowerPC Solaris powerpcle-*-solaris*
5094 PowerPC Windows NT powerpcle-*-cygwin32
5095 PowerPC Netware powerpc-*-netware*
5096 Harris/CXUX m88k m88*-harris-cxux*
5097 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5098 ns32k-utek-sysv* ns32k-utek-*
5099 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5100 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5101 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5102 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5103 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5105 * Changes to command line processing
5107 The new `--args' feature can be used to specify command-line arguments
5108 for the inferior from gdb's command line.
5110 * Changes to key bindings
5112 There is a new `operate-and-get-next' function bound to `C-o'.
5114 *** Changes in GDB 5.1.1
5116 Fix compile problem on DJGPP.
5118 Fix a problem with floating-point registers on the i386 being
5121 Fix to stop GDB crashing on .debug_str debug info.
5123 Numerous documentation fixes.
5125 Numerous testsuite fixes.
5127 *** Changes in GDB 5.1:
5129 * New native configurations
5131 Alpha FreeBSD alpha*-*-freebsd*
5132 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5133 MIPS GNU/Linux mips*-*-linux*
5134 MIPS SGI Irix 6.x mips*-sgi-irix6*
5135 ia64 AIX ia64-*-aix*
5136 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5140 Motorola 68HC11 and 68HC12 m68hc11-elf
5142 UltraSparc running GNU/Linux sparc64-*-linux*
5144 * OBSOLETE configurations and files
5146 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5147 Harris/CXUX m88k m88*-harris-cxux*
5148 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5149 ns32k-utek-sysv* ns32k-utek-*
5150 TI TMS320C80 tic80-*-*
5152 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5153 PowerPC Solaris powerpcle-*-solaris*
5154 PowerPC Windows NT powerpcle-*-cygwin32
5155 PowerPC Netware powerpc-*-netware*
5156 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5157 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5158 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5159 Apple Macintosh (MPW) host N/A
5161 stuff.c (Program to stuff files into a specially prepared space in kdb)
5162 kdb-start.c (Main loop for the standalone kernel debugger)
5164 Configurations that have been declared obsolete in this release have
5165 been commented out. Unless there is activity to revive these
5166 configurations, the next release of GDB will have their sources
5167 permanently REMOVED.
5169 * REMOVED configurations and files
5171 Altos 3068 m68*-altos-*
5172 Convex c1-*-*, c2-*-*
5174 ARM RISCix arm-*-* (as host)
5178 * GDB has been converted to ISO C.
5180 GDB's source code has been converted to ISO C. In particular, the
5181 sources are fully protoized, and rely on standard headers being
5186 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5188 * The MI enabled by default.
5190 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5191 revised and enabled by default. Packages which use GDB as a debugging
5192 engine behind a UI or another front end are encouraged to switch to
5193 using the GDB/MI interface, instead of the old annotations interface
5194 which is now deprecated.
5196 * Support for debugging Pascal programs.
5198 GDB now includes support for debugging Pascal programs. The following
5199 main features are supported:
5201 - Pascal-specific data types such as sets;
5203 - automatic recognition of Pascal sources based on file-name
5206 - Pascal-style display of data types, variables, and functions;
5208 - a Pascal expression parser.
5210 However, some important features are not yet supported.
5212 - Pascal string operations are not supported at all;
5214 - there are some problems with boolean types;
5216 - Pascal type hexadecimal constants are not supported
5217 because they conflict with the internal variables format;
5219 - support for Pascal objects and classes is not full yet;
5221 - unlike Pascal, GDB is case-sensitive for symbol names.
5223 * Changes in completion.
5225 Commands such as `shell', `run' and `set args', which pass arguments
5226 to inferior programs, now complete on file names, similar to what
5227 users expect at the shell prompt.
5229 Commands which accept locations, such as `disassemble', `print',
5230 `breakpoint', `until', etc. now complete on filenames as well as
5231 program symbols. Thus, if you type "break foob TAB", and the source
5232 files linked into the programs include `foobar.c', that file name will
5233 be one of the candidates for completion. However, file names are not
5234 considered for completion after you typed a colon that delimits a file
5235 name from a name of a function in that file, as in "break foo.c:bar".
5237 `set demangle-style' completes on available demangling styles.
5239 * New platform-independent commands:
5241 It is now possible to define a post-hook for a command as well as a
5242 hook that runs before the command. For more details, see the
5243 documentation of `hookpost' in the GDB manual.
5245 * Changes in GNU/Linux native debugging.
5247 Support for debugging multi-threaded programs has been completely
5248 revised for all platforms except m68k and sparc. You can now debug as
5249 many threads as your system allows you to have.
5251 Attach/detach is supported for multi-threaded programs.
5253 Support for SSE registers was added for x86. This doesn't work for
5254 multi-threaded programs though.
5256 * Changes in MIPS configurations.
5258 Multi-arch support is enabled for all MIPS configurations.
5260 GDB can now be built as native debugger on SGI Irix 6.x systems for
5261 debugging n32 executables. (Debugging 64-bit executables is not yet
5264 * Unified support for hardware watchpoints in all x86 configurations.
5266 Most (if not all) native x86 configurations support hardware-assisted
5267 breakpoints and watchpoints in a unified manner. This support
5268 implements debug register sharing between watchpoints, which allows to
5269 put a virtually infinite number of watchpoints on the same address,
5270 and also supports watching regions up to 16 bytes with several debug
5273 The new maintenance command `maintenance show-debug-regs' toggles
5274 debugging print-outs in functions that insert, remove, and test
5275 watchpoints and hardware breakpoints.
5277 * Changes in the DJGPP native configuration.
5279 New command ``info dos sysinfo'' displays assorted information about
5280 the CPU, OS, memory, and DPMI server.
5282 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5283 display information about segment descriptors stored in GDT, LDT, and
5286 New commands ``info dos pde'' and ``info dos pte'' display entries
5287 from Page Directory and Page Tables (for now works with CWSDPMI only).
5288 New command ``info dos address-pte'' displays the Page Table entry for
5289 a given linear address.
5291 GDB can now pass command lines longer than 126 characters to the
5292 program being debugged (requires an update to the libdbg.a library
5293 which is part of the DJGPP development kit).
5295 DWARF2 debug info is now supported.
5297 It is now possible to `step' and `next' through calls to `longjmp'.
5299 * Changes in documentation.
5301 All GDB documentation was converted to GFDL, the GNU Free
5302 Documentation License.
5304 Tracepoints-related commands are now fully documented in the GDB
5307 TUI, the Text-mode User Interface, is now documented in the manual.
5309 Tracepoints-related commands are now fully documented in the GDB
5312 The "GDB Internals" manual now has an index. It also includes
5313 documentation of `ui_out' functions, GDB coding standards, x86
5314 hardware watchpoints, and memory region attributes.
5316 * GDB's version number moved to ``version.in''
5318 The Makefile variable VERSION has been replaced by the file
5319 ``version.in''. People creating GDB distributions should update the
5320 contents of this file.
5324 GUD support is now a standard part of the EMACS distribution.
5326 *** Changes in GDB 5.0:
5328 * Improved support for debugging FP programs on x86 targets
5330 Unified and much-improved support for debugging floating-point
5331 programs on all x86 targets. In particular, ``info float'' now
5332 displays the FP registers in the same format on all x86 targets, with
5333 greater level of detail.
5335 * Improvements and bugfixes in hardware-assisted watchpoints
5337 It is now possible to watch array elements, struct members, and
5338 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5339 on x86 targets no longer erroneously trigger when the address is
5342 * Improvements in the native DJGPP version of GDB
5344 The distribution now includes all the scripts and auxiliary files
5345 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5346 machines ``out of the box''.
5348 The DJGPP version can now debug programs that use signals. It is
5349 possible to catch signals that happened in the debuggee, deliver
5350 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5351 would kill the program being debugged.) Programs that hook hardware
5352 interrupts (keyboard, timer, etc.) can also be debugged.
5354 It is now possible to debug DJGPP programs that redirect their
5355 standard handles or switch them to raw (as opposed to cooked) mode, or
5356 even close them. The command ``run < foo > bar'' works as expected,
5357 and ``info terminal'' reports useful information about the debuggee's
5358 terminal, including raw/cooked mode, redirection, etc.
5360 The DJGPP version now uses termios functions for console I/O, which
5361 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5364 DOS-style file names with drive letters are now fully supported by
5367 It is now possible to debug DJGPP programs that switch their working
5368 directory. It is also possible to rerun the debuggee any number of
5369 times without restarting GDB; thus, you can use the same setup,
5370 breakpoints, etc. for many debugging sessions.
5372 * New native configurations
5374 ARM GNU/Linux arm*-*-linux*
5375 PowerPC GNU/Linux powerpc-*-linux*
5379 Motorola MCore mcore-*-*
5380 x86 VxWorks i[3456]86-*-vxworks*
5381 PowerPC VxWorks powerpc-*-vxworks*
5382 TI TMS320C80 tic80-*-*
5384 * OBSOLETE configurations
5386 Altos 3068 m68*-altos-*
5387 Convex c1-*-*, c2-*-*
5389 ARM RISCix arm-*-* (as host)
5392 Configurations that have been declared obsolete will be commented out,
5393 but the code will be left in place. If there is no activity to revive
5394 these configurations before the next release of GDB, the sources will
5395 be permanently REMOVED.
5397 * Gould support removed
5399 Support for the Gould PowerNode and NP1 has been removed.
5401 * New features for SVR4
5403 On SVR4 native platforms (such as Solaris), if you attach to a process
5404 without first loading a symbol file, GDB will now attempt to locate and
5405 load symbols from the running process's executable file.
5407 * Many C++ enhancements
5409 C++ support has been greatly improved. Overload resolution now works properly
5410 in almost all cases. RTTI support is on the way.
5412 * Remote targets can connect to a sub-program
5414 A popen(3) style serial-device has been added. This device starts a
5415 sub-process (such as a stand-alone simulator) and then communicates
5416 with that. The sub-program to run is specified using the syntax
5417 ``|<program> <args>'' vis:
5419 (gdb) set remotedebug 1
5420 (gdb) target extended-remote |mn10300-elf-sim program-args
5422 * MIPS 64 remote protocol
5424 A long standing bug in the mips64 remote protocol where by GDB
5425 expected certain 32 bit registers (ex SR) to be transfered as 32
5426 instead of 64 bits has been fixed.
5428 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5429 added to provide backward compatibility with older versions of GDB.
5431 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5433 The command ``set remotebinarydownload'' command has been replaced by
5434 ``set remote X-packet''. Other commands in ``set remote'' family
5435 include ``set remote P-packet''.
5437 * Breakpoint commands accept ranges.
5439 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5440 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5441 ``tracepoint passcount'' also accepts a range of tracepoints.
5443 * ``apropos'' command added.
5445 The ``apropos'' command searches through command names and
5446 documentation strings, printing out matches, making it much easier to
5447 try to find a command that does what you are looking for.
5451 A new machine oriented interface (MI) has been added to GDB. This
5452 interface is designed for debug environments running GDB as a separate
5453 process. This is part of the long term libGDB project. See the
5454 "GDB/MI" chapter of the GDB manual for further information. It can be
5455 enabled by configuring with:
5457 .../configure --enable-gdbmi
5459 *** Changes in GDB-4.18:
5461 * New native configurations
5463 HP-UX 10.20 hppa*-*-hpux10.20
5464 HP-UX 11.x hppa*-*-hpux11.0*
5465 M68K GNU/Linux m68*-*-linux*
5469 Fujitsu FR30 fr30-*-elf*
5470 Intel StrongARM strongarm-*-*
5471 Mitsubishi D30V d30v-*-*
5473 * OBSOLETE configurations
5475 Gould PowerNode, NP1 np1-*-*, pn-*-*
5477 Configurations that have been declared obsolete will be commented out,
5478 but the code will be left in place. If there is no activity to revive
5479 these configurations before the next release of GDB, the sources will
5480 be permanently REMOVED.
5484 As a compatibility experiment, GDB's source files buildsym.h and
5485 buildsym.c have been converted to pure standard C, no longer
5486 containing any K&R compatibility code. We believe that all systems in
5487 use today either come with a standard C compiler, or have a GCC port
5488 available. If this is not true, please report the affected
5489 configuration to bug-gdb@gnu.org immediately. See the README file for
5490 information about getting a standard C compiler if you don't have one
5495 GDB now uses readline 2.2.
5497 * set extension-language
5499 You can now control the mapping between filename extensions and source
5500 languages by using the `set extension-language' command. For instance,
5501 you can ask GDB to treat .c files as C++ by saying
5502 set extension-language .c c++
5503 The command `info extensions' lists all of the recognized extensions
5504 and their associated languages.
5506 * Setting processor type for PowerPC and RS/6000
5508 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5509 you can use the `set processor' command to specify what variant of the
5510 PowerPC family you are debugging. The command
5514 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5515 following PowerPC and RS6000 variants:
5517 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5518 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5520 403GC IBM PowerPC 403GC
5521 505 Motorola PowerPC 505
5522 860 Motorola PowerPC 860 or 850
5523 601 Motorola PowerPC 601
5524 602 Motorola PowerPC 602
5525 603 Motorola/IBM PowerPC 603 or 603e
5526 604 Motorola PowerPC 604 or 604e
5527 750 Motorola/IBM PowerPC 750 or 750
5529 At the moment, this command just tells GDB what to name the
5530 special-purpose processor registers. Since almost all the affected
5531 registers are inaccessible to user-level programs, this command is
5532 only useful for remote debugging in its present form.
5536 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5537 more extensive support for HP-UX. Added features include shared
5538 library support, kernel threads and hardware watchpoints for 11.00,
5539 support for HP's ANSI C and C++ compilers, and a compatibility mode
5540 for xdb and dbx commands.
5544 HP's donation includes the new concept of catchpoints, which is a
5545 generalization of the old catch command. On HP-UX, it is now possible
5546 to catch exec, fork, and vfork, as well as library loading.
5548 This means that the existing catch command has changed; its first
5549 argument now specifies the type of catch to be set up. See the
5550 output of "help catch" for a list of catchpoint types.
5552 * Debugging across forks
5554 On HP-UX, you can choose which process to debug when a fork() happens
5559 HP has donated a curses-based terminal user interface (TUI). To get
5560 it, build with --enable-tui. Although this can be enabled for any
5561 configuration, at present it only works for native HP debugging.
5563 * GDB remote protocol additions
5565 A new protocol packet 'X' that writes binary data is now available.
5566 Default behavior is to try 'X', then drop back to 'M' if the stub
5567 fails to respond. The settable variable `remotebinarydownload'
5568 allows explicit control over the use of 'X'.
5570 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5571 full 64-bit address. The command
5573 set remoteaddresssize 32
5575 can be used to revert to the old behaviour. For existing remote stubs
5576 the change should not be noticed, as the additional address information
5579 In order to assist in debugging stubs, you may use the maintenance
5580 command `packet' to send any text string to the stub. For instance,
5582 maint packet heythere
5584 sends the packet "$heythere#<checksum>". Note that it is very easy to
5585 disrupt a debugging session by sending the wrong packet at the wrong
5588 The compare-sections command allows you to compare section data on the
5589 target to what is in the executable file without uploading or
5590 downloading, by comparing CRC checksums.
5592 * Tracing can collect general expressions
5594 You may now collect general expressions at tracepoints. This requires
5595 further additions to the target-side stub; see tracepoint.c and
5596 doc/agentexpr.texi for further details.
5598 * mask-address variable for Mips
5600 For Mips targets, you may control the zeroing of the upper 32 bits of
5601 a 64-bit address by entering `set mask-address on'. This is mainly
5602 of interest to users of embedded R4xxx and R5xxx processors.
5604 * Higher serial baud rates
5606 GDB's serial code now allows you to specify baud rates 57600, 115200,
5607 230400, and 460800 baud. (Note that your host system may not be able
5608 to achieve all of these rates.)
5612 The i960 configuration now includes an initial implementation of a
5613 builtin simulator, contributed by Jim Wilson.
5616 *** Changes in GDB-4.17:
5618 * New native configurations
5620 Alpha GNU/Linux alpha*-*-linux*
5621 Unixware 2.x i[3456]86-unixware2*
5622 Irix 6.x mips*-sgi-irix6*
5623 PowerPC GNU/Linux powerpc-*-linux*
5624 PowerPC Solaris powerpcle-*-solaris*
5625 Sparc GNU/Linux sparc-*-linux*
5626 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5630 Argonaut Risc Chip (ARC) arc-*-*
5631 Hitachi H8/300S h8300*-*-*
5632 Matsushita MN10200 w/simulator mn10200-*-*
5633 Matsushita MN10300 w/simulator mn10300-*-*
5634 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5635 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5636 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5637 Mitsubishi D10V w/simulator d10v-*-*
5638 Mitsubishi M32R/D w/simulator m32r-*-elf*
5639 Tsqware Sparclet sparclet-*-*
5640 NEC V850 w/simulator v850-*-*
5642 * New debugging protocols
5644 ARM with RDI protocol arm*-*-*
5645 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5646 DDB and LSI variants of PMON protocol mips*-*-*
5647 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5648 PowerPC with SDS protocol powerpc{,le}-*-eabi
5649 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5653 All configurations can now understand and use the DWARF 2 debugging
5654 format. The choice is automatic, if the symbol file contains DWARF 2
5659 GDB now includes basic Java language support. This support is
5660 only useful with Java compilers that produce native machine code.
5662 * solib-absolute-prefix and solib-search-path
5664 For SunOS and SVR4 shared libraries, you may now set the prefix for
5665 loading absolute shared library symbol files, and the search path for
5666 locating non-absolute shared library symbol files.
5668 * Live range splitting
5670 GDB can now effectively debug code for which GCC has performed live
5671 range splitting as part of its optimization. See gdb/doc/LRS for
5672 more details on the expected format of the stabs information.
5676 GDB's support for the GNU Hurd, including thread debugging, has been
5677 updated to work with current versions of the Hurd.
5681 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5682 instruction set. ARM GDB automatically detects when Thumb
5683 instructions are in use, and adjusts disassembly and backtracing
5688 GDB's MIPS target configurations now handle the MIP16 16-bit
5693 GDB now includes support for overlays; if an executable has been
5694 linked such that multiple sections are based at the same address, GDB
5695 will decide which section to use for symbolic info. You can choose to
5696 control the decision manually, using overlay commands, or implement
5697 additional target-side support and use "overlay load-target" to bring
5698 in the overlay mapping. Do "help overlay" for more detail.
5702 The command "info symbol <address>" displays information about
5703 the symbol at the specified address.
5707 The standard remote protocol now includes an extension that allows
5708 asynchronous collection and display of trace data. This requires
5709 extensive support in the target-side debugging stub. Tracing mode
5710 includes a new interaction mode in GDB and new commands: see the
5711 file tracepoint.c for more details.
5715 Configurations for embedded MIPS now include a simulator contributed
5716 by Cygnus Solutions. The simulator supports the instruction sets
5717 of most MIPS variants.
5721 Sparc configurations may now include the ERC32 simulator contributed
5722 by the European Space Agency. The simulator is not built into
5723 Sparc targets by default; configure with --enable-sim to include it.
5727 For target configurations that may include multiple variants of a
5728 basic architecture (such as MIPS and SH), you may now set the
5729 architecture explicitly. "set arch" sets, "info arch" lists
5730 the possible architectures.
5732 *** Changes in GDB-4.16:
5734 * New native configurations
5736 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5737 M68K NetBSD m68k-*-netbsd*
5738 PowerPC AIX 4.x powerpc-*-aix*
5739 PowerPC MacOS powerpc-*-macos*
5740 PowerPC Windows NT powerpcle-*-cygwin32
5741 RS/6000 AIX 4.x rs6000-*-aix4*
5745 ARM with RDP protocol arm-*-*
5746 I960 with MON960 i960-*-coff
5747 MIPS VxWorks mips*-*-vxworks*
5748 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5749 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5751 Matra Sparclet sparclet-*-*
5755 The powerpc-eabi configuration now includes the PSIM simulator,
5756 contributed by Andrew Cagney, with assistance from Mike Meissner.
5757 PSIM is a very elaborate model of the PowerPC, including not only
5758 basic instruction set execution, but also details of execution unit
5759 performance and I/O hardware. See sim/ppc/README for more details.
5763 GDB now works with Solaris 2.5.
5765 * Windows 95/NT native
5767 GDB will now work as a native debugger on Windows 95 and Windows NT.
5768 To build it from source, you must use the "gnu-win32" environment,
5769 which uses a DLL to emulate enough of Unix to run the GNU tools.
5770 Further information, binaries, and sources are available at
5771 ftp.cygnus.com, under pub/gnu-win32.
5773 * dont-repeat command
5775 If a user-defined command includes the command `dont-repeat', then the
5776 command will not be repeated if the user just types return. This is
5777 useful if the command is time-consuming to run, so that accidental
5778 extra keystrokes don't run the same command many times.
5780 * Send break instead of ^C
5782 The standard remote protocol now includes an option to send a break
5783 rather than a ^C to the target in order to interrupt it. By default,
5784 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5786 * Remote protocol timeout
5788 The standard remote protocol includes a new variable `remotetimeout'
5789 that allows you to set the number of seconds before GDB gives up trying
5790 to read from the target. The default value is 2.
5792 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5794 By default GDB will automatically keep track of objects as they are
5795 loaded and unloaded by the dynamic linker. By using the command `set
5796 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5797 when shared library events occur, thus allowing you to set breakpoints
5798 in shared libraries which are explicitly loaded by the inferior.
5800 Note this feature does not work on hpux8. On hpux9 you must link
5801 /usr/lib/end.o into your program. This feature should work
5802 automatically on hpux10.
5804 * Irix 5.x hardware watchpoint support
5806 Irix 5 configurations now support the use of hardware watchpoints.
5808 * Mips protocol "SYN garbage limit"
5810 When debugging a Mips target using the `target mips' protocol, you
5811 may set the number of characters that GDB will ignore by setting
5812 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5813 every character. The default value is 1050.
5815 * Recording and replaying remote debug sessions
5817 If you set `remotelogfile' to the name of a file, gdb will write to it
5818 a recording of a remote debug session. This recording may then be
5819 replayed back to gdb using "gdbreplay". See gdbserver/README for
5820 details. This is useful when you have a problem with GDB while doing
5821 remote debugging; you can make a recording of the session and send it
5822 to someone else, who can then recreate the problem.
5824 * Speedups for remote debugging
5826 GDB includes speedups for downloading and stepping MIPS systems using
5827 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5828 and more efficient S-record downloading.
5830 * Memory use reductions and statistics collection
5832 GDB now uses less memory and reports statistics about memory usage.
5833 Try the `maint print statistics' command, for example.
5835 *** Changes in GDB-4.15:
5837 * Psymtabs for XCOFF
5839 The symbol reader for AIX GDB now uses partial symbol tables. This
5840 can greatly improve startup time, especially for large executables.
5842 * Remote targets use caching
5844 Remote targets now use a data cache to speed up communication with the
5845 remote side. The data cache could lead to incorrect results because
5846 it doesn't know about volatile variables, thus making it impossible to
5847 debug targets which use memory mapped I/O devices. `set remotecache
5848 off' turns the the data cache off.
5850 * Remote targets may have threads
5852 The standard remote protocol now includes support for multiple threads
5853 in the target system, using new protocol commands 'H' and 'T'. See
5854 gdb/remote.c for details.
5858 If GDB is configured with `--enable-netrom', then it will include
5859 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5860 acts as though it is a bank of ROM on the target board, but you can
5861 write into it over the network. GDB's support consists only of
5862 support for fast loading into the emulated ROM; to debug, you must use
5863 another protocol, such as standard remote protocol. The usual
5864 sequence is something like
5866 target nrom <netrom-hostname>
5868 target remote <netrom-hostname>:1235
5872 GDB now includes support for the Apple Macintosh, as a host only. It
5873 may be run as either an MPW tool or as a standalone application, and
5874 it can debug through the serial port. All the usual GDB commands are
5875 available, but to the target command, you must supply "serial" as the
5876 device type instead of "/dev/ttyXX". See mpw-README in the main
5877 directory for more information on how to build. The MPW configuration
5878 scripts */mpw-config.in support only a few targets, and only the
5879 mips-idt-ecoff target has been tested.
5883 GDB configuration now uses autoconf. This is not user-visible,
5884 but does simplify configuration and building.
5888 GDB now supports hpux10.
5890 *** Changes in GDB-4.14:
5892 * New native configurations
5894 x86 FreeBSD i[345]86-*-freebsd
5895 x86 NetBSD i[345]86-*-netbsd
5896 NS32k NetBSD ns32k-*-netbsd
5897 Sparc NetBSD sparc-*-netbsd
5901 A29K VxWorks a29k-*-vxworks
5902 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5903 CPU32 EST-300 emulator m68*-*-est*
5904 PowerPC ELF powerpc-*-elf
5907 * Alpha OSF/1 support for procfs
5909 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5910 possible to attach to running processes. As the mounting of the /proc
5911 filesystem is optional on the Alpha, GDB automatically determines
5912 the availability of /proc during startup. This can lead to problems
5913 if /proc is unmounted after GDB has been started.
5915 * Arguments to user-defined commands
5917 User commands may accept up to 10 arguments separated by whitespace.
5918 Arguments are accessed within the user command via $arg0..$arg9. A
5921 print $arg0 + $arg1 + $arg2
5923 To execute the command use:
5926 Defines the command "adder" which prints the sum of its three arguments.
5927 Note the arguments are text substitutions, so they may reference variables,
5928 use complex expressions, or even perform inferior function calls.
5930 * New `if' and `while' commands
5932 This makes it possible to write more sophisticated user-defined
5933 commands. Both commands take a single argument, which is the
5934 expression to evaluate, and must be followed by the commands to
5935 execute, one per line, if the expression is nonzero, the list being
5936 terminated by the word `end'. The `if' command list may include an
5937 `else' word, which causes the following commands to be executed only
5938 if the expression is zero.
5940 * Fortran source language mode
5942 GDB now includes partial support for Fortran 77. It will recognize
5943 Fortran programs and can evaluate a subset of Fortran expressions, but
5944 variables and functions may not be handled correctly. GDB will work
5945 with G77, but does not yet know much about symbols emitted by other
5948 * Better HPUX support
5950 Most debugging facilities now work on dynamic executables for HPPAs
5951 running hpux9 or later. You can attach to running dynamically linked
5952 processes, but by default the dynamic libraries will be read-only, so
5953 for instance you won't be able to put breakpoints in them. To change
5954 that behavior do the following before running the program:
5960 This will cause the libraries to be mapped private and read-write.
5961 To revert to the normal behavior, do this:
5967 You cannot set breakpoints or examine data in the library until after
5968 the library is loaded if the function/data symbols do not have
5971 GDB can now also read debug symbols produced by the HP C compiler on
5972 HPPAs (sorry, no C++, Fortran or 68k support).
5974 * Target byte order now dynamically selectable
5976 You can choose which byte order to use with a target system, via the
5977 commands "set endian big" and "set endian little", and you can see the
5978 current setting by using "show endian". You can also give the command
5979 "set endian auto", in which case GDB will use the byte order
5980 associated with the executable. Currently, only embedded MIPS
5981 configurations support dynamic selection of target byte order.
5983 * New DOS host serial code
5985 This version uses DPMI interrupts to handle buffered I/O, so you
5986 no longer need to run asynctsr when debugging boards connected to
5989 *** Changes in GDB-4.13:
5991 * New "complete" command
5993 This lists all the possible completions for the rest of the line, if it
5994 were to be given as a command itself. This is intended for use by emacs.
5996 * Trailing space optional in prompt
5998 "set prompt" no longer adds a space for you after the prompt you set. This
5999 allows you to set a prompt which ends in a space or one that does not.
6001 * Breakpoint hit counts
6003 "info break" now displays a count of the number of times the breakpoint
6004 has been hit. This is especially useful in conjunction with "ignore"; you
6005 can ignore a large number of breakpoint hits, look at the breakpoint info
6006 to see how many times the breakpoint was hit, then run again, ignoring one
6007 less than that number, and this will get you quickly to the last hit of
6010 * Ability to stop printing at NULL character
6012 "set print null-stop" will cause GDB to stop printing the characters of
6013 an array when the first NULL is encountered. This is useful when large
6014 arrays actually contain only short strings.
6016 * Shared library breakpoints
6018 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6019 breakpoints in shared libraries before the executable is run.
6021 * Hardware watchpoints
6023 There is a new hardware breakpoint for the watch command for sparclite
6024 targets. See gdb/sparclite/hw_breakpoint.note.
6026 Hardware watchpoints are also now supported under GNU/Linux.
6030 Annotations have been added. These are for use with graphical interfaces,
6031 and are still experimental. Currently only gdba.el uses these.
6033 * Improved Irix 5 support
6035 GDB now works properly with Irix 5.2.
6037 * Improved HPPA support
6039 GDB now works properly with the latest GCC and GAS.
6041 * New native configurations
6043 Sequent PTX4 i[34]86-sequent-ptx4
6044 HPPA running OSF/1 hppa*-*-osf*
6045 Atari TT running SVR4 m68*-*-sysv4*
6046 RS/6000 LynxOS rs6000-*-lynxos*
6050 OS/9000 i[34]86-*-os9k
6051 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6054 * Hitachi SH7000 and E7000-PC ICE support
6056 There is now support for communicating with the Hitachi E7000-PC ICE.
6057 This is available automatically when GDB is configured for the SH.
6061 As usual, a variety of small fixes and improvements, both generic
6062 and configuration-specific. See the ChangeLog for more detail.
6064 *** Changes in GDB-4.12:
6066 * Irix 5 is now supported
6070 GDB-4.12 on the HPPA has a number of changes which make it unable
6071 to debug the output from the currently released versions of GCC and
6072 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6073 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6074 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6077 *** Changes in GDB-4.11:
6079 * User visible changes:
6083 The "set remotedebug" option is now consistent between the mips remote
6084 target, remote targets using the gdb-specific protocol, UDI (AMD's
6085 debug protocol for the 29k) and the 88k bug monitor. It is now an
6086 integer specifying a debug level (normally 0 or 1, but 2 means more
6087 debugging info for the mips target).
6089 * DEC Alpha native support
6091 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6092 debug info, but GDB works fairly well with the DEC compiler and should
6093 work with a future GCC release. See the README file for a few
6094 Alpha-specific notes.
6096 * Preliminary thread implementation
6098 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6100 * LynxOS native and target support for 386
6102 This release has been hosted on LynxOS 2.2, and also can be configured
6103 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6106 * Improvements in C++ mangling/demangling.
6108 This release has much better g++ debugging, specifically in name
6109 mangling/demangling, virtual function calls, print virtual table,
6110 call methods, ...etc.
6112 *** Changes in GDB-4.10:
6114 * User visible changes:
6116 Remote debugging using the GDB-specific (`target remote') protocol now
6117 supports the `load' command. This is only useful if you have some
6118 other way of getting the stub to the target system, and you can put it
6119 somewhere in memory where it won't get clobbered by the download.
6121 Filename completion now works.
6123 When run under emacs mode, the "info line" command now causes the
6124 arrow to point to the line specified. Also, "info line" prints
6125 addresses in symbolic form (as well as hex).
6127 All vxworks based targets now support a user settable option, called
6128 vxworks-timeout. This option represents the number of seconds gdb
6129 should wait for responses to rpc's. You might want to use this if
6130 your vxworks target is, perhaps, a slow software simulator or happens
6131 to be on the far side of a thin network line.
6135 This release contains support for using a DEC alpha as a GDB host for
6136 cross debugging. Native alpha debugging is not supported yet.
6139 *** Changes in GDB-4.9:
6143 This is the first GDB release which is accompanied by a matching testsuite.
6144 The testsuite requires installation of dejagnu, which should be available
6145 via ftp from most sites that carry GNU software.
6149 'Cfront' style demangling has had its name changed to 'ARM' style, to
6150 emphasize that it was written from the specifications in the C++ Annotated
6151 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6152 disclaimers, it still generated too much confusion with users attempting to
6153 use gdb with AT&T cfront.
6157 GDB now uses a standard remote interface to a simulator library.
6158 So far, the library contains simulators for the Zilog Z8001/2, the
6159 Hitachi H8/300, H8/500 and Super-H.
6161 * New targets supported
6163 H8/300 simulator h8300-hitachi-hms or h8300hms
6164 H8/500 simulator h8500-hitachi-hms or h8500hms
6165 SH simulator sh-hitachi-hms or sh
6166 Z8000 simulator z8k-zilog-none or z8ksim
6167 IDT MIPS board over serial line mips-idt-ecoff
6169 Cross-debugging to GO32 targets is supported. It requires a custom
6170 version of the i386-stub.c module which is integrated with the
6171 GO32 memory extender.
6173 * New remote protocols
6175 MIPS remote debugging protocol.
6177 * New source languages supported
6179 This version includes preliminary support for Chill, a Pascal like language
6180 used by telecommunications companies. Chill support is also being integrated
6181 into the GNU compiler, but we don't know when it will be publically available.
6184 *** Changes in GDB-4.8:
6186 * HP Precision Architecture supported
6188 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6189 version of this support was available as a set of patches from the
6190 University of Utah. GDB does not support debugging of programs
6191 compiled with the HP compiler, because HP will not document their file
6192 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6193 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6195 Many problems in the preliminary version have been fixed.
6197 * Faster and better demangling
6199 We have improved template demangling and fixed numerous bugs in the GNU style
6200 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6201 character types (wchar_t) are now supported. Demangling of each symbol is now
6202 only done once, and is cached when the symbol table for a file is read in.
6203 This results in a small increase in memory usage for C programs, a moderate
6204 increase in memory usage for C++ programs, and a fantastic speedup in
6207 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6208 from the specifications in the Annotated Reference Manual, which AT&T's
6209 compiler does not actually implement.
6211 * G++ multiple inheritance compiler problem
6213 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6214 inheritance lattices was reworked to properly discover ambiguities. We
6215 recently found an example which causes this new algorithm to fail in a
6216 very subtle way, producing bad debug information for those classes.
6217 The file 'gcc.patch' (in this directory) can be applied to gcc to
6218 circumvent the problem. A future GCC release will contain a complete
6221 The previous G++ debug info problem (mentioned below for the gdb-4.7
6222 release) is fixed in gcc version 2.3.2.
6224 * Improved configure script
6226 The `configure' script will now attempt to guess your system type if
6227 you don't supply a host system type. The old scheme of supplying a
6228 host system triplet is preferable over using this. All the magic is
6229 done in the new `config.guess' script. Examine it for details.
6231 We have also brought our configure script much more in line with the FSF's
6232 version. It now supports the --with-xxx options. In particular,
6233 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6234 The resulting GDB will not be able to read arbitrary object file formats --
6235 only the format ``expected'' to be used on the configured target system.
6236 We hope to make this the default in a future release.
6238 * Documentation improvements
6240 There's new internal documentation on how to modify GDB, and how to
6241 produce clean changes to the code. We implore people to read it
6242 before submitting changes.
6244 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6245 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6246 `info' files are also provided. To build `info' files from scratch,
6247 you will need the latest `makeinfo' release, which will be available in
6248 a future texinfo-X.Y release.
6250 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6251 We're not sure exactly which versions have this problem, but it has
6252 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6253 or better. If that isn't possible, there is a patch in
6254 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6255 around this problem.
6259 GDB now supports array constants that can be used in expressions typed in by
6260 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6261 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6264 The new directory `gdb/sparclite' contains a program that demonstrates
6265 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6267 * New native hosts supported
6269 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6270 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6272 * New targets supported
6274 AMD 29k family via UDI a29k-amd-udi or udi29k
6276 * New file formats supported
6278 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6279 HPUX core files, and SCO 3.2v2 core files.
6283 Attaching to processes now works again; thanks for the many bug reports.
6285 We have also stomped on a bunch of core dumps caused by
6286 printf_filtered("%s") problems.
6288 We eliminated a copyright problem on the rpc and ptrace header files
6289 for VxWorks, which was discovered at the last minute during the 4.7
6290 release. You should now be able to build a VxWorks GDB.
6292 You can now interrupt gdb while an attached process is running. This
6293 will cause the attached process to stop, and give control back to GDB.
6295 We fixed problems caused by using too many file descriptors
6296 for reading symbols from object files and libraries. This was
6297 especially a problem for programs that used many (~100) shared
6300 The `step' command now only enters a subroutine if there is line number
6301 information for the subroutine. Otherwise it acts like the `next'
6302 command. Previously, `step' would enter subroutines if there was
6303 any debugging information about the routine. This avoids problems
6304 when using `cc -g1' on MIPS machines.
6306 * Internal improvements
6308 GDB's internal interfaces have been improved to make it easier to support
6309 debugging of multiple languages in the future.
6311 GDB now uses a common structure for symbol information internally.
6312 Minimal symbols (derived from linkage symbols in object files), partial
6313 symbols (from a quick scan of debug information), and full symbols
6314 contain a common subset of information, making it easier to write
6315 shared code that handles any of them.
6317 * New command line options
6319 We now accept --silent as an alias for --quiet.
6323 The memory-mapped-malloc library is now licensed under the GNU Library
6324 General Public License.
6326 *** Changes in GDB-4.7:
6328 * Host/native/target split
6330 GDB has had some major internal surgery to untangle the support for
6331 hosts and remote targets. Now, when you configure GDB for a remote
6332 target, it will no longer load in all of the support for debugging
6333 local programs on the host. When fully completed and tested, this will
6334 ensure that arbitrary host/target combinations are possible.
6336 The primary conceptual shift is to separate the non-portable code in
6337 GDB into three categories. Host specific code is required any time GDB
6338 is compiled on that host, regardless of the target. Target specific
6339 code relates to the peculiarities of the target, but can be compiled on
6340 any host. Native specific code is everything else: it can only be
6341 built when the host and target are the same system. Child process
6342 handling and core file support are two common `native' examples.
6344 GDB's use of /proc for controlling Unix child processes is now cleaner.
6345 It has been split out into a single module under the `target_ops' vector,
6346 plus two native-dependent functions for each system that uses /proc.
6348 * New hosts supported
6350 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6351 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6352 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6354 * New targets supported
6356 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6357 68030 and CPU32 m68030-*-*, m68332-*-*
6359 * New native hosts supported
6361 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6362 (386bsd is not well tested yet)
6363 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6365 * New file formats supported
6367 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6368 supports reading of `a.out.adobe' object files, which are an a.out
6369 format extended with minimal information about multiple sections.
6373 `show copying' is the same as the old `info copying'.
6374 `show warranty' is the same as `info warrantee'.
6375 These were renamed for consistency. The old commands continue to work.
6377 `info handle' is a new alias for `info signals'.
6379 You can now define pre-command hooks, which attach arbitrary command
6380 scripts to any command. The commands in the hook will be executed
6381 prior to the user's command. You can also create a hook which will be
6382 executed whenever the program stops. See gdb.texinfo.
6386 We now deal with Cfront style name mangling, and can even extract type
6387 info from mangled symbols. GDB can automatically figure out which
6388 symbol mangling style your C++ compiler uses.
6390 Calling of methods and virtual functions has been improved as well.
6394 The crash that occured when debugging Sun Ansi-C compiled binaries is
6395 fixed. This was due to mishandling of the extra N_SO stabs output
6398 We also finally got Ultrix 4.2 running in house, and fixed core file
6399 support, with help from a dozen people on the net.
6401 John M. Farrell discovered that the reason that single-stepping was so
6402 slow on all of the Mips based platforms (primarily SGI and DEC) was
6403 that we were trying to demangle and lookup a symbol used for internal
6404 purposes on every instruction that was being stepped through. Changing
6405 the name of that symbol so that it couldn't be mistaken for a C++
6406 mangled symbol sped things up a great deal.
6408 Rich Pixley sped up symbol lookups in general by getting much smarter
6409 about when C++ symbol mangling is necessary. This should make symbol
6410 completion (TAB on the command line) much faster. It's not as fast as
6411 we'd like, but it's significantly faster than gdb-4.6.
6415 A new user controllable variable 'call_scratch_address' can
6416 specify the location of a scratch area to be used when GDB
6417 calls a function in the target. This is necessary because the
6418 usual method of putting the scratch area on the stack does not work
6419 in systems that have separate instruction and data spaces.
6421 We integrated changes to support the 29k UDI (Universal Debugger
6422 Interface), but discovered at the last minute that we didn't have all
6423 of the appropriate copyright paperwork. We are working with AMD to
6424 resolve this, and hope to have it available soon.
6428 We have sped up the remote serial line protocol, especially for targets
6429 with lots of registers. It now supports a new `expedited status' ('T')
6430 message which can be used in place of the existing 'S' status message.
6431 This allows the remote stub to send only the registers that GDB
6432 needs to make a quick decision about single-stepping or conditional
6433 breakpoints, eliminating the need to fetch the entire register set for
6434 each instruction being stepped through.
6436 The GDB remote serial protocol now implements a write-through cache for
6437 registers, only re-reading the registers if the target has run.
6439 There is also a new remote serial stub for SPARC processors. You can
6440 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6441 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6442 processor with a serial port.
6446 Configure.in files have become much easier to read and modify. A new
6447 `table driven' format makes it more obvious what configurations are
6448 supported, and what files each one uses.
6452 There is a new opcodes library which will eventually contain all of the
6453 disassembly routines and opcode tables. At present, it only contains
6454 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6455 disassembler (binutils/objdump) to share these routines.
6457 The libiberty library is now copylefted under the GNU Library General
6458 Public License. This allows more liberal use, and was done so libg++
6459 can use it. This makes no difference to GDB, since the Library License
6460 grants all the rights from the General Public License.
6464 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6465 reference to the stabs symbol info used by the debugger. It is (as far
6466 as we know) the only published document on this fascinating topic. We
6467 encourage you to read it, compare it to the stabs information on your
6468 system, and send improvements on the document in general (to
6469 bug-gdb@prep.ai.mit.edu).
6471 And, of course, many bugs have been fixed.
6474 *** Changes in GDB-4.6:
6476 * Better support for C++ function names
6478 GDB now accepts as input the "demangled form" of C++ overloaded function
6479 names and member function names, and can do command completion on such names
6480 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6481 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6482 Make use of command completion, it is your friend.
6484 GDB also now accepts a variety of C++ mangled symbol formats. They are
6485 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6486 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6487 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6488 for the list of formats.
6490 * G++ symbol mangling problem
6492 Recent versions of gcc have a bug in how they emit debugging information for
6493 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6494 directory) can be applied to gcc to fix the problem. Alternatively, if you
6495 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6496 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6497 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6500 * New 'maintenance' command
6502 All of the commands related to hacking GDB internals have been moved out of
6503 the main command set, and now live behind the 'maintenance' command. This
6504 can also be abbreviated as 'mt'. The following changes were made:
6506 dump-me -> maintenance dump-me
6507 info all-breakpoints -> maintenance info breakpoints
6508 printmsyms -> maintenance print msyms
6509 printobjfiles -> maintenance print objfiles
6510 printpsyms -> maintenance print psymbols
6511 printsyms -> maintenance print symbols
6513 The following commands are new:
6515 maintenance demangle Call internal GDB demangler routine to
6516 demangle a C++ link name and prints the result.
6517 maintenance print type Print a type chain for a given symbol
6519 * Change to .gdbinit file processing
6521 We now read the $HOME/.gdbinit file before processing the argv arguments
6522 (e.g. reading symbol files or core files). This allows global parameters to
6523 be set, which will apply during the symbol reading. The ./.gdbinit is still
6524 read after argv processing.
6526 * New hosts supported
6528 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6530 GNU/Linux support i386-unknown-linux or linux
6532 We are also including code to support the HP/PA running BSD and HPUX. This
6533 is almost guaranteed not to work, as we didn't have time to test or build it
6534 for this release. We are including it so that the more adventurous (or
6535 masochistic) of you can play with it. We also had major problems with the
6536 fact that the compiler that we got from HP doesn't support the -g option.
6539 * New targets supported
6541 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6543 * More smarts about finding #include files
6545 GDB now remembers the compilation directory for all include files, and for
6546 all files from which C is generated (like yacc and lex sources). This
6547 greatly improves GDB's ability to find yacc/lex sources, and include files,
6548 especially if you are debugging your program from a directory different from
6549 the one that contains your sources.
6551 We also fixed a bug which caused difficulty with listing and setting
6552 breakpoints in include files which contain C code. (In the past, you had to
6553 try twice in order to list an include file that you hadn't looked at before.)
6555 * Interesting infernals change
6557 GDB now deals with arbitrary numbers of sections, where the symbols for each
6558 section must be relocated relative to that section's landing place in the
6559 target's address space. This work was needed to support ELF with embedded
6560 stabs used by Solaris-2.0.
6562 * Bug fixes (of course!)
6564 There have been loads of fixes for the following things:
6565 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6566 i960, stabs, DOS(GO32), procfs, etc...
6568 See the ChangeLog for details.
6570 *** Changes in GDB-4.5:
6572 * New machines supported (host and target)
6574 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6576 SGI Irix-4.x mips-sgi-irix4 or iris4
6578 * New malloc package
6580 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6581 Mmalloc is capable of handling mutiple heaps of memory. It is also
6582 capable of saving a heap to a file, and then mapping it back in later.
6583 This can be used to greatly speedup the startup of GDB by using a
6584 pre-parsed symbol table which lives in a mmalloc managed heap. For
6585 more details, please read mmalloc/mmalloc.texi.
6589 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6590 'help info proc' for details.
6592 * MIPS ecoff symbol table format
6594 The code that reads MIPS symbol table format is now supported on all hosts.
6595 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6598 * File name changes for MS-DOS
6600 Many files in the config directories have been renamed to make it easier to
6601 support GDB on MS-DOSe systems (which have very restrictive file name
6602 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6603 environment) is close to working but has some remaining problems. Note
6604 that debugging of DOS programs is not supported, due to limitations
6605 in the ``operating system'', but it can be used to host cross-debugging.
6607 * Cross byte order fixes
6609 Many fixes have been made to support cross debugging of Sparc and MIPS
6610 targets from hosts whose byte order differs.
6612 * New -mapped and -readnow options
6614 If memory-mapped files are available on your system through the 'mmap'
6615 system call, you can use the -mapped option on the `file' or
6616 `symbol-file' commands to cause GDB to write the symbols from your
6617 program into a reusable file. If the program you are debugging is
6618 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6619 Future GDB debugging sessions will notice the presence of this file,
6620 and will quickly map in symbol information from it, rather than reading
6621 the symbol table from the executable program. Using the '-mapped'
6622 option in a GDB `file' or `symbol-file' command has the same effect as
6623 starting GDB with the '-mapped' command-line option.
6625 You can cause GDB to read the entire symbol table immediately by using
6626 the '-readnow' option with any of the commands that load symbol table
6627 information (or on the GDB command line). This makes the command
6628 slower, but makes future operations faster.
6630 The -mapped and -readnow options are typically combined in order to
6631 build a `fred.syms' file that contains complete symbol information.
6632 A simple GDB invocation to do nothing but build a `.syms' file for future
6635 gdb -batch -nx -mapped -readnow programname
6637 The `.syms' file is specific to the host machine on which GDB is run.
6638 It holds an exact image of GDB's internal symbol table. It cannot be
6639 shared across multiple host platforms.
6641 * longjmp() handling
6643 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6644 siglongjmp() without losing control. This feature has not yet been ported to
6645 all systems. It currently works on many 386 platforms, all MIPS-based
6646 platforms (SGI, DECstation, etc), and Sun3/4.
6650 Preliminary work has been put in to support the new Solaris OS from Sun. At
6651 this time, it can control and debug processes, but it is not capable of
6656 As always, many many bug fixes. The major areas were with g++, and mipsread.
6657 People using the MIPS-based platforms should experience fewer mysterious
6658 crashes and trashed symbol tables.
6660 *** Changes in GDB-4.4:
6662 * New machines supported (host and target)
6664 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6666 BSD Reno on Vax vax-dec-bsd
6667 Ultrix on Vax vax-dec-ultrix
6669 * New machines supported (target)
6671 AMD 29000 embedded, using EBMON a29k-none-none
6675 GDB continues to improve its handling of C++. `References' work better.
6676 The demangler has also been improved, and now deals with symbols mangled as
6677 per the Annotated C++ Reference Guide.
6679 GDB also now handles `stabs' symbol information embedded in MIPS
6680 `ecoff' symbol tables. Since the ecoff format was not easily
6681 extensible to handle new languages such as C++, this appeared to be a
6682 good way to put C++ debugging info into MIPS binaries. This option
6683 will be supported in the GNU C compiler, version 2, when it is
6686 * New features for SVR4
6688 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6689 shared libraries. Debugging dynamically linked programs should present
6690 only minor differences from debugging statically linked programs.
6692 The `info proc' command will print out information about any process
6693 on an SVR4 system (including the one you are debugging). At the moment,
6694 it prints the address mappings of the process.
6696 If you bring up GDB on another SVR4 system, please send mail to
6697 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6699 * Better dynamic linking support in SunOS
6701 Reading symbols from shared libraries which contain debugging symbols
6702 now works properly. However, there remain issues such as automatic
6703 skipping of `transfer vector' code during function calls, which
6704 make it harder to debug code in a shared library, than to debug the
6705 same code linked statically.
6709 GDB is now using the latest `getopt' routines from the FSF. This
6710 version accepts the -- prefix for options with long names. GDB will
6711 continue to accept the old forms (-option and +option) as well.
6712 Various single letter abbreviations for options have been explicity
6713 added to the option table so that they won't get overshadowed in the
6714 future by other options that begin with the same letter.
6718 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6719 Many assorted bugs have been handled. Many more remain to be handled.
6720 See the various ChangeLog files (primarily in gdb and bfd) for details.
6723 *** Changes in GDB-4.3:
6725 * New machines supported (host and target)
6727 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6728 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6729 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6731 * Almost SCO Unix support
6733 We had hoped to support:
6734 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6735 (except for core file support), but we discovered very late in the release
6736 that it has problems with process groups that render gdb unusable. Sorry
6737 about that. I encourage people to fix it and post the fixes.
6739 * Preliminary ELF and DWARF support
6741 GDB can read ELF object files on System V Release 4, and can handle
6742 debugging records for C, in DWARF format, in ELF files. This support
6743 is preliminary. If you bring up GDB on another SVR4 system, please
6744 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6749 GDB now uses the latest `readline' library. One user-visible change
6750 is that two tabs will list possible command completions, which previously
6751 required typing M-? (meta-question mark, or ESC ?).
6755 The `stepi' bug that many of you noticed has been squashed.
6756 Many bugs in C++ have been handled. Many more remain to be handled.
6757 See the various ChangeLog files (primarily in gdb and bfd) for details.
6759 * State of the MIPS world (in case you wondered):
6761 GDB can understand the symbol tables emitted by the compilers
6762 supplied by most vendors of MIPS-based machines, including DEC. These
6763 symbol tables are in a format that essentially nobody else uses.
6765 Some versions of gcc come with an assembler post-processor called
6766 mips-tfile. This program is required if you want to do source-level
6767 debugging of gcc-compiled programs. I believe FSF does not ship
6768 mips-tfile with gcc version 1, but it will eventually come with gcc
6771 Debugging of g++ output remains a problem. g++ version 1.xx does not
6772 really support it at all. (If you're lucky, you should be able to get
6773 line numbers and stack traces to work, but no parameters or local
6774 variables.) With some work it should be possible to improve the
6777 When gcc version 2 is released, you will have somewhat better luck.
6778 However, even then you will get confusing results for inheritance and
6781 We will eventually provide full debugging of g++ output on
6782 DECstations. This will probably involve some kind of stabs-in-ecoff
6783 encapulation, but the details have not been worked out yet.
6786 *** Changes in GDB-4.2:
6788 * Improved configuration
6790 Only one copy of `configure' exists now, and it is not self-modifying.
6791 Porting BFD is simpler.
6795 The `step' and `next' commands now only stop at the first instruction
6796 of a source line. This prevents the multiple stops that used to occur
6797 in switch statements, for-loops, etc. `Step' continues to stop if a
6798 function that has debugging information is called within the line.
6802 Lots of small bugs fixed. More remain.
6804 * New host supported (not target)
6806 Intel 386 PC clone running Mach i386-none-mach
6809 *** Changes in GDB-4.1:
6811 * Multiple source language support
6813 GDB now has internal scaffolding to handle several source languages.
6814 It determines the type of each source file from its filename extension,
6815 and will switch expression parsing and number formatting to match the
6816 language of the function in the currently selected stack frame.
6817 You can also specifically set the language to be used, with
6818 `set language c' or `set language modula-2'.
6822 GDB now has preliminary support for the GNU Modula-2 compiler,
6823 currently under development at the State University of New York at
6824 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6825 continue through the fall of 1991 and into 1992.
6827 Other Modula-2 compilers are currently not supported, and attempting to
6828 debug programs compiled with them will likely result in an error as the
6829 symbol table is read. Feel free to work on it, though!
6831 There are hooks in GDB for strict type checking and range checking,
6832 in the `Modula-2 philosophy', but they do not currently work.
6836 GDB can now write to executable and core files (e.g. patch
6837 a variable's value). You must turn this switch on, specify
6838 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6839 by assigning a new value to a variable. Modifications take
6842 * Automatic SunOS shared library reading
6844 When you run your program, GDB automatically determines where its
6845 shared libraries (if any) have been loaded, and reads their symbols.
6846 The `share' command is no longer needed. This also works when
6847 examining core files.
6851 You can specify the number of lines that the `list' command shows.
6854 * New machines supported (host and target)
6856 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6857 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6858 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6860 * New hosts supported (not targets)
6862 IBM RT/PC: romp-ibm-aix or rtpc
6864 * New targets supported (not hosts)
6866 AMD 29000 embedded with COFF a29k-none-coff
6867 AMD 29000 embedded with a.out a29k-none-aout
6868 Ultracomputer remote kernel debug a29k-nyu-kern
6870 * New remote interfaces
6876 *** Changes in GDB-4.0:
6880 Wide output is wrapped at good places to make the output more readable.
6882 Gdb now supports cross-debugging from a host machine of one type to a
6883 target machine of another type. Communication with the target system
6884 is over serial lines. The ``target'' command handles connecting to the
6885 remote system; the ``load'' command will download a program into the
6886 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6887 also supports debugging of realtime processes running under VxWorks,
6888 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6889 stub on the target system.
6891 New CPUs supported include the AMD 29000 and Intel 960.
6893 GDB now reads object files and symbol tables via a ``binary file''
6894 library, which allows a single copy of GDB to debug programs of multiple
6895 object file types such as a.out and coff.
6897 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6898 refcard.dvi and refcard.ps are available to format it).
6901 * Control-Variable user interface simplified
6903 All variables that control the operation of the debugger can be set
6904 by the ``set'' command, and displayed by the ``show'' command.
6906 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6907 ``Show prompt'' produces the response:
6908 Gdb's prompt is new-gdb=>.
6910 What follows are the NEW set commands. The command ``help set'' will
6911 print a complete list of old and new set commands. ``help set FOO''
6912 will give a longer description of the variable FOO. ``show'' will show
6913 all of the variable descriptions and their current settings.
6915 confirm on/off: Enables warning questions for operations that are
6916 hard to recover from, e.g. rerunning the program while
6917 it is already running. Default is ON.
6919 editing on/off: Enables EMACS style command line editing
6920 of input. Previous lines can be recalled with
6921 control-P, the current line can be edited with control-B,
6922 you can search for commands with control-R, etc.
6925 history filename NAME: NAME is where the gdb command history
6926 will be stored. The default is .gdb_history,
6927 or the value of the environment variable
6930 history size N: The size, in commands, of the command history. The
6931 default is 256, or the value of the environment variable
6934 history save on/off: If this value is set to ON, the history file will
6935 be saved after exiting gdb. If set to OFF, the
6936 file will not be saved. The default is OFF.
6938 history expansion on/off: If this value is set to ON, then csh-like
6939 history expansion will be performed on
6940 command line input. The default is OFF.
6942 radix N: Sets the default radix for input and output. It can be set
6943 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6944 in the current radix, so "set radix 10" is always a no-op.
6946 height N: This integer value is the number of lines on a page. Default
6947 is 24, the current `stty rows'' setting, or the ``li#''
6948 setting from the termcap entry matching the environment
6951 width N: This integer value is the number of characters on a line.
6952 Default is 80, the current `stty cols'' setting, or the ``co#''
6953 setting from the termcap entry matching the environment
6956 Note: ``set screensize'' is obsolete. Use ``set height'' and
6957 ``set width'' instead.
6959 print address on/off: Print memory addresses in various command displays,
6960 such as stack traces and structure values. Gdb looks
6961 more ``symbolic'' if you turn this off; it looks more
6962 ``machine level'' with it on. Default is ON.
6964 print array on/off: Prettyprint arrays. New convenient format! Default
6967 print demangle on/off: Print C++ symbols in "source" form if on,
6970 print asm-demangle on/off: Same, for assembler level printouts
6973 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6976 * Support for Epoch Environment.
6978 The epoch environment is a version of Emacs v18 with windowing. One
6979 new command, ``inspect'', is identical to ``print'', except that if you
6980 are running in the epoch environment, the value is printed in its own
6984 * Support for Shared Libraries
6986 GDB can now debug programs and core files that use SunOS shared libraries.
6987 Symbols from a shared library cannot be referenced
6988 before the shared library has been linked with the program (this
6989 happens after you type ``run'' and before the function main() is entered).
6990 At any time after this linking (including when examining core files
6991 from dynamically linked programs), gdb reads the symbols from each
6992 shared library when you type the ``sharedlibrary'' command.
6993 It can be abbreviated ``share''.
6995 sharedlibrary REGEXP: Load shared object library symbols for files
6996 matching a unix regular expression. No argument
6997 indicates to load symbols for all shared libraries.
6999 info sharedlibrary: Status of loaded shared libraries.
7004 A watchpoint stops execution of a program whenever the value of an
7005 expression changes. Checking for this slows down execution
7006 tremendously whenever you are in the scope of the expression, but is
7007 quite useful for catching tough ``bit-spreader'' or pointer misuse
7008 problems. Some machines such as the 386 have hardware for doing this
7009 more quickly, and future versions of gdb will use this hardware.
7011 watch EXP: Set a watchpoint (breakpoint) for an expression.
7013 info watchpoints: Information about your watchpoints.
7015 delete N: Deletes watchpoint number N (same as breakpoints).
7016 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7017 enable N: Re-enables watchpoint number N (same as breakpoints).
7020 * C++ multiple inheritance
7022 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7025 * C++ exception handling
7027 Gdb now supports limited C++ exception handling. Besides the existing
7028 ability to breakpoint on an exception handler, gdb can breakpoint on
7029 the raising of an exception (before the stack is peeled back to the
7032 catch FOO: If there is a FOO exception handler in the dynamic scope,
7033 set a breakpoint to catch exceptions which may be raised there.
7034 Multiple exceptions (``catch foo bar baz'') may be caught.
7036 info catch: Lists all exceptions which may be caught in the
7037 current stack frame.
7040 * Minor command changes
7042 The command ``call func (arg, arg, ...)'' now acts like the print
7043 command, except it does not print or save a value if the function's result
7044 is void. This is similar to dbx usage.
7046 The ``up'' and ``down'' commands now always print the frame they end up
7047 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7048 frames without printing.
7050 * New directory command
7052 'dir' now adds directories to the FRONT of the source search path.
7053 The path starts off empty. Source files that contain debug information
7054 about the directory in which they were compiled can be found even
7055 with an empty path; Sun CC and GCC include this information. If GDB can't
7056 find your source file in the current directory, type "dir .".
7058 * Configuring GDB for compilation
7060 For normal use, type ``./configure host''. See README or gdb.texinfo
7063 GDB now handles cross debugging. If you are remotely debugging between
7064 two different machines, type ``./configure host -target=targ''.
7065 Host is the machine where GDB will run; targ is the machine
7066 where the program that you are debugging will run.