1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.1
6 * The commands 'info variables/functions/types' now show the source line
7 numbers of symbol definitions when available.
9 * 'info proc' now works on running processes on FreeBSD systems and core
10 files created on FreeBSD systems.
16 Control display of debugging info regarding the FreeBSD native target.
18 set|show varsize-limit
19 This new setting allows the user to control the maximum size of Ada
20 objects being printed when those objects have a variable type,
21 instead of that maximum size being hardcoded to 65536 bytes.
23 set|show record btrace cpu
24 Controls the processor to be used for enabling errata workarounds for
29 RiscV ELF riscv*-*-elf
31 *** Changes in GDB 8.1
33 * GDB now supports dynamically creating arbitrary register groups specified
34 in XML target descriptions. This allows for finer grain grouping of
35 registers on systems with a large amount of registers.
37 * The 'ptype' command now accepts a '/o' flag, which prints the
38 offsets and sizes of fields in a struct, like the pahole(1) tool.
40 * New "--readnever" command line option instructs GDB to not read each
41 symbol file's symbolic debug information. This makes startup faster
42 but at the expense of not being able to perform symbolic debugging.
43 This option is intended for use cases where symbolic debugging will
44 not be used, e.g., when you only need to dump the debuggee's core.
46 * GDB now uses the GNU MPFR library, if available, to emulate target
47 floating-point arithmetic during expression evaluation when the target
48 uses different floating-point formats than the host. At least version
49 3.1 of GNU MPFR is required.
51 * GDB now supports access to the guarded-storage-control registers and the
52 software-based guarded-storage broadcast control registers on IBM z14.
54 * On Unix systems, GDB now supports transmitting environment variables
55 that are to be set or unset to GDBserver. These variables will
56 affect the environment to be passed to the remote inferior.
58 To inform GDB of environment variables that are to be transmitted to
59 GDBserver, use the "set environment" command. Only user set
60 environment variables are sent to GDBserver.
62 To inform GDB of environment variables that are to be unset before
63 the remote inferior is started by the GDBserver, use the "unset
66 * Completion improvements
68 ** GDB can now complete function parameters in linespecs and
69 explicit locations without quoting. When setting breakpoints,
70 quoting around functions names to help with TAB-completion is
71 generally no longer necessary. For example, this now completes
74 (gdb) b function(in[TAB]
77 Related, GDB is no longer confused with completing functions in
78 C++ anonymous namespaces:
81 (gdb) b (anonymous namespace)::[TAB][TAB]
82 (anonymous namespace)::a_function()
83 (anonymous namespace)::b_function()
85 ** GDB now has much improved linespec and explicit locations TAB
86 completion support, that better understands what you're
87 completing and offers better suggestions. For example, GDB no
88 longer offers data symbols as possible completions when you're
91 ** GDB now TAB-completes label symbol names.
93 ** The "complete" command now mimics TAB completion accurately.
95 * New command line options (gcore)
98 Dump all memory mappings.
100 * Breakpoints on C++ functions are now set on all scopes by default
102 By default, breakpoints on functions/methods are now interpreted as
103 specifying all functions with the given name ignoring missing
104 leading scopes (namespaces and classes).
106 For example, assuming a C++ program with symbols named:
111 both commands "break func()" and "break B::func()" set a breakpoint
114 You can use the new flag "-qualified" to override this. This makes
115 GDB interpret the specified function name as a complete
116 fully-qualified name instead. For example, using the same C++
117 program, the "break -q B::func" command sets a breakpoint on
118 "B::func", only. A parameter has been added to the Python
119 gdb.Breakpoint constructor to achieve the same result when creating
120 a breakpoint from Python.
122 * Breakpoints on functions marked with C++ ABI tags
124 GDB can now set breakpoints on functions marked with C++ ABI tags
125 (e.g., [abi:cxx11]). See here for a description of ABI tags:
126 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
128 Functions with a C++11 abi tag are demangled/displayed like this:
130 function[abi:cxx11](int)
133 You can now set a breakpoint on such functions simply as if they had
136 (gdb) b function(int)
138 Or if you need to disambiguate between tags, like:
140 (gdb) b function[abi:other_tag](int)
142 Tab completion was adjusted accordingly as well.
146 ** New events gdb.new_inferior, gdb.inferior_deleted, and
147 gdb.new_thread are emitted. See the manual for further
148 description of these.
150 ** A new function, "gdb.rbreak" has been added to the Python API.
151 This function allows the setting of a large number of breakpoints
152 via a regex pattern in Python. See the manual for further details.
154 ** Python breakpoints can now accept explicit locations. See the
155 manual for a further description of this feature.
158 * New features in the GDB remote stub, GDBserver
160 ** GDBserver is now able to start inferior processes with a
161 specified initial working directory.
163 The user can set the desired working directory to be used from
164 GDB using the new "set cwd" command.
166 ** New "--selftest" command line option runs some GDBserver self
167 tests. These self tests are disabled in releases.
169 ** On Unix systems, GDBserver now does globbing expansion and variable
170 substitution in inferior command line arguments.
172 This is done by starting inferiors using a shell, like GDB does.
173 See "set startup-with-shell" in the user manual for how to disable
174 this from GDB when using "target extended-remote". When using
175 "target remote", you can disable the startup with shell by using the
176 new "--no-startup-with-shell" GDBserver command line option.
178 ** On Unix systems, GDBserver now supports receiving environment
179 variables that are to be set or unset from GDB. These variables
180 will affect the environment to be passed to the inferior.
182 * When catching an Ada exception raised with a message, GDB now prints
183 the message in the catchpoint hit notification. In GDB/MI mode, that
184 information is provided as an extra field named "exception-message"
185 in the *stopped notification.
187 * Trait objects can now be inspected When debugging Rust code. This
188 requires compiler support which will appear in Rust 1.24.
192 QEnvironmentHexEncoded
193 Inform GDBserver of an environment variable that is to be passed to
194 the inferior when starting it.
197 Inform GDBserver of an environment variable that is to be unset
198 before starting the remote inferior.
201 Inform GDBserver that the environment should be reset (i.e.,
202 user-set environment variables should be unset).
205 Indicates whether the inferior must be started with a shell or not.
208 Tell GDBserver that the inferior to be started should use a specific
211 * The "maintenance print c-tdesc" command now takes an optional
212 argument which is the file name of XML target description.
214 * The "maintenance selftest" command now takes an optional argument to
215 filter the tests to be run.
217 * The "enable", and "disable" commands now accept a range of
218 breakpoint locations, e.g. "enable 1.3-5".
223 Set and show the current working directory for the inferior.
226 Set and show compilation command used for compiling and injecting code
227 with the 'compile' commands.
229 set debug separate-debug-file
230 show debug separate-debug-file
231 Control the display of debug output about separate debug file search.
233 set dump-excluded-mappings
234 show dump-excluded-mappings
235 Control whether mappings marked with the VM_DONTDUMP flag should be
236 dumped when generating a core file.
239 List the registered selftests.
242 Start the debugged program stopping at the first instruction.
245 Control display of debugging messages related to OpenRISC targets.
247 set|show print type nested-type-limit
248 Set and show the limit of nesting level for nested types that the
249 type printer will show.
251 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
254 * Safer/improved support for debugging with no debug info
256 GDB no longer assumes functions with no debug information return
259 This means that GDB now refuses to call such functions unless you
260 tell it the function's type, by either casting the call to the
261 declared return type, or by casting the function to a function
262 pointer of the right type, and calling that:
264 (gdb) p getenv ("PATH")
265 'getenv' has unknown return type; cast the call to its declared return type
266 (gdb) p (char *) getenv ("PATH")
267 $1 = 0x7fffffffe "/usr/local/bin:/"...
268 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
269 $2 = 0x7fffffffe "/usr/local/bin:/"...
271 Similarly, GDB no longer assumes that global variables with no debug
272 info have type 'int', and refuses to print the variable's value
273 unless you tell it the variable's type:
276 'var' has unknown type; cast it to its declared type
280 * New native configurations
282 FreeBSD/aarch64 aarch64*-*-freebsd*
283 FreeBSD/arm arm*-*-freebsd*
287 FreeBSD/aarch64 aarch64*-*-freebsd*
288 FreeBSD/arm arm*-*-freebsd*
289 OpenRISC ELF or1k*-*-elf
291 * Removed targets and native configurations
293 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
295 *** Changes in GDB 8.0
297 * GDB now supports access to the PKU register on GNU/Linux. The register is
298 added by the Memory Protection Keys for Userspace feature which will be
299 available in future Intel CPUs.
301 * GDB now supports C++11 rvalue references.
305 ** New functions to start, stop and access a running btrace recording.
306 ** Rvalue references are now supported in gdb.Type.
308 * GDB now supports recording and replaying rdrand and rdseed Intel 64
311 * Building GDB and GDBserver now requires a C++11 compiler.
313 For example, GCC 4.8 or later.
315 It is no longer possible to build GDB or GDBserver with a C
316 compiler. The --disable-build-with-cxx configure option has been
319 * Building GDB and GDBserver now requires GNU make >= 3.81.
321 It is no longer supported to build GDB or GDBserver with another
322 implementation of the make program or an earlier version of GNU make.
324 * Native debugging on MS-Windows supports command-line redirection
326 Command-line arguments used for starting programs on MS-Windows can
327 now include redirection symbols supported by native Windows shells,
328 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
329 as "run", "start", and "set args", as well as the corresponding MI
332 * Support for thread names on MS-Windows.
334 GDB now catches and handles the special exception that programs
335 running on MS-Windows use to assign names to threads in the
338 * Support for Java programs compiled with gcj has been removed.
340 * User commands now accept an unlimited number of arguments.
341 Previously, only up to 10 was accepted.
343 * The "eval" command now expands user-defined command arguments.
345 This makes it easier to process a variable number of arguments:
350 eval "print $arg%d", $i
355 * Target descriptions can now describe registers for sparc32 and sparc64.
357 * GDB now supports DWARF version 5 (debug information format).
358 Its .debug_names index is not yet supported.
360 * New native configurations
362 FreeBSD/mips mips*-*-freebsd
366 Synopsys ARC arc*-*-elf32
367 FreeBSD/mips mips*-*-freebsd
369 * Removed targets and native configurations
371 Alpha running FreeBSD alpha*-*-freebsd*
372 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
377 Erases all the flash memory regions reported by the target.
379 maint print arc arc-instruction address
380 Print internal disassembler information about instruction at a given address.
384 set disassembler-options
385 show disassembler-options
386 Controls the passing of target specific information to the disassembler.
387 If it is necessary to specify more than one disassembler option then
388 multiple options can be placed together into a comma separated list.
389 The default value is the empty string. Currently, the only supported
390 targets are ARM, PowerPC and S/390.
395 Erases all the flash memory regions reported by the target. This is
396 equivalent to the CLI command flash-erase.
398 -file-list-shared-libraries
399 List the shared libraries in the program. This is
400 equivalent to the CLI command "info shared".
403 Catchpoints stopping the program when Ada exceptions are
404 handled. This is equivalent to the CLI command "catch handlers".
406 *** Changes in GDB 7.12
408 * GDB and GDBserver now build with a C++ compiler by default.
410 The --enable-build-with-cxx configure option is now enabled by
411 default. One must now explicitly configure with
412 --disable-build-with-cxx in order to build with a C compiler. This
413 option will be removed in a future release.
415 * GDBserver now supports recording btrace without maintaining an active
418 * GDB now supports a negative repeat count in the 'x' command to examine
419 memory backward from the given address. For example:
422 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
423 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
424 (gdb) x/-5i 0x0000000000400580
425 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
426 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
427 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
428 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
429 0x40057b <main(int, char**)+25>:
430 callq 0x400536 <Func1(int, char const*)>
432 * Fortran: Support structures with fields of dynamic types and
433 arrays of dynamic types.
435 * The symbol dumping maintenance commands have new syntax.
436 maint print symbols [-pc address] [--] [filename]
437 maint print symbols [-objfile objfile] [-source source] [--] [filename]
438 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
439 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
440 maint print msymbols [-objfile objfile] [--] [filename]
442 * GDB now supports multibit bitfields and enums in target register
445 * New Python-based convenience function $_as_string(val), which returns
446 the textual representation of a value. This function is especially
447 useful to obtain the text label of an enum value.
449 * Intel MPX bound violation handling.
451 Segmentation faults caused by a Intel MPX boundary violation
452 now display the kind of violation (upper or lower), the memory
453 address accessed and the memory bounds, along with the usual
454 signal received and code location.
458 Program received signal SIGSEGV, Segmentation fault
459 Upper bound violation while accessing address 0x7fffffffc3b3
460 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
461 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
463 * Rust language support.
464 GDB now supports debugging programs written in the Rust programming
465 language. See https://www.rust-lang.org/ for more information about
468 * Support for running interpreters on specified input/output devices
470 GDB now supports a new mechanism that allows frontends to provide
471 fully featured GDB console views, as a better alternative to
472 building such views on top of the "-interpreter-exec console"
473 command. See the new "new-ui" command below. With that command,
474 frontends can now start GDB in the traditional command-line mode
475 running in an embedded terminal emulator widget, and create a
476 separate MI interpreter running on a specified i/o device. In this
477 way, GDB handles line editing, history, tab completion, etc. in the
478 console all by itself, and the GUI uses the separate MI interpreter
479 for its own control and synchronization, invisible to the command
482 * The "catch syscall" command catches groups of related syscalls.
484 The "catch syscall" command now supports catching a group of related
485 syscalls using the 'group:' or 'g:' prefix.
490 skip -gfile file-glob-pattern
491 skip -function function
492 skip -rfunction regular-expression
493 A generalized form of the skip command, with new support for
494 glob-style file names and regular expressions for function names.
495 Additionally, a file spec and a function spec may now be combined.
497 maint info line-table REGEXP
498 Display the contents of GDB's internal line table data struture.
501 Run any GDB unit tests that were compiled in.
504 Start a new user interface instance running INTERP as interpreter,
505 using the TTY file for input/output.
509 ** gdb.Breakpoint objects have a new attribute "pending", which
510 indicates whether the breakpoint is pending.
511 ** Three new breakpoint-related events have been added:
512 gdb.breakpoint_created, gdb.breakpoint_modified, and
513 gdb.breakpoint_deleted.
516 Signal ("set") the given MS-Windows event object. This is used in
517 conjunction with the Windows JIT debugging (AeDebug) support, where
518 the OS suspends a crashing process until a debugger can attach to
519 it. Resuming the crashing process, in order to debug it, is done by
522 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
523 was added in GDBserver, including JIT compiling fast tracepoint's
524 conditional expression bytecode into native code.
526 * Support for various remote target protocols and ROM monitors has
529 target m32rsdi Remote M32R debugging over SDI
530 target mips MIPS remote debugging protocol
531 target pmon PMON ROM monitor
532 target ddb NEC's DDB variant of PMON for Vr4300
533 target rockhopper NEC RockHopper variant of PMON
534 target lsi LSI variant of PMO
536 * Support for tracepoints and fast tracepoints on powerpc-linux,
537 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
538 including JIT compiling fast tracepoint's conditional expression
539 bytecode into native code.
541 * MI async record =record-started now includes the method and format used for
542 recording. For example:
544 =record-started,thread-group="i1",method="btrace",format="bts"
546 * MI async record =thread-selected now includes the frame field. For example:
548 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
552 Andes NDS32 nds32*-*-elf
554 *** Changes in GDB 7.11
556 * GDB now supports debugging kernel-based threads on FreeBSD.
558 * Per-inferior thread numbers
560 Thread numbers are now per inferior instead of global. If you're
561 debugging multiple inferiors, GDB displays thread IDs using a
562 qualified INF_NUM.THR_NUM form. For example:
566 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
567 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
568 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
569 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
571 As consequence, thread numbers as visible in the $_thread
572 convenience variable and in Python's InferiorThread.num attribute
573 are no longer unique between inferiors.
575 GDB now maintains a second thread ID per thread, referred to as the
576 global thread ID, which is the new equivalent of thread numbers in
577 previous releases. See also $_gthread below.
579 For backwards compatibility, MI's thread IDs always refer to global
582 * Commands that accept thread IDs now accept the qualified
583 INF_NUM.THR_NUM form as well. For example:
586 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
589 * In commands that accept a list of thread IDs, you can now refer to
590 all threads of an inferior using a star wildcard. GDB accepts
591 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
592 refer to all threads of the current inferior. For example, "info
595 * You can use "info threads -gid" to display the global thread ID of
598 * The new convenience variable $_gthread holds the global number of
601 * The new convenience variable $_inferior holds the number of the
604 * GDB now displays the ID and name of the thread that hit a breakpoint
605 or received a signal, if your program is multi-threaded. For
608 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
609 Thread 1 "main" received signal SIGINT, Interrupt.
611 * Record btrace now supports non-stop mode.
613 * Support for tracepoints on aarch64-linux was added in GDBserver.
615 * The 'record instruction-history' command now indicates speculative execution
616 when using the Intel Processor Trace recording format.
618 * GDB now allows users to specify explicit locations, bypassing
619 the linespec parser. This feature is also available to GDB/MI
622 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
623 GDB now is able to debug both AArch64 applications and ARM applications
626 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
627 including JIT compiling fast tracepoint's conditional expression bytecode
630 * GDB now supports displaced stepping on AArch64 GNU/Linux.
632 * "info threads", "info inferiors", "info display", "info checkpoints"
633 and "maint info program-spaces" now list the corresponding items in
634 ascending ID order, for consistency with all other "info" commands.
636 * In Ada, the overloads selection menu has been enhanced to display the
637 parameter types and the return types for the matching overloaded subprograms.
641 maint set target-non-stop (on|off|auto)
642 maint show target-non-stop
643 Control whether GDB targets always operate in non-stop mode even if
644 "set non-stop" is "off". The default is "auto", meaning non-stop
645 mode is enabled if supported by the target.
647 maint set bfd-sharing
648 maint show bfd-sharing
649 Control the reuse of bfd objects.
653 Control display of debugging info regarding bfd caching.
657 Control display of debugging info regarding FreeBSD threads.
659 set remote multiprocess-extensions-packet
660 show remote multiprocess-extensions-packet
661 Set/show the use of the remote protocol multiprocess extensions.
663 set remote thread-events
664 show remote thread-events
665 Set/show the use of thread create/exit events.
667 set ada print-signatures on|off
668 show ada print-signatures"
669 Control whether parameter types and return types are displayed in overloads
670 selection menus. It is activaled (@code{on}) by default.
674 Controls the maximum size of memory, in bytes, that GDB will
675 allocate for value contents. Prevents incorrect programs from
676 causing GDB to allocate overly large buffers. Default is 64k.
678 * The "disassemble" command accepts a new modifier: /s.
679 It prints mixed source+disassembly like /m with two differences:
680 - disassembled instructions are now printed in program order, and
681 - and source for all relevant files is now printed.
682 The "/m" option is now considered deprecated: its "source-centric"
683 output hasn't proved useful in practice.
685 * The "record instruction-history" command accepts a new modifier: /s.
686 It behaves exactly like /m and prints mixed source+disassembly.
688 * The "set scheduler-locking" command supports a new mode "replay".
689 It behaves like "off" in record mode and like "on" in replay mode.
691 * Support for various ROM monitors has been removed:
693 target dbug dBUG ROM monitor for Motorola ColdFire
694 target picobug Motorola picobug monitor
695 target dink32 DINK32 ROM monitor for PowerPC
696 target m32r Renesas M32R/D ROM monitor
697 target mon2000 mon2000 ROM monitor
698 target ppcbug PPCBUG ROM monitor for PowerPC
700 * Support for reading/writing memory and extracting values on architectures
701 whose memory is addressable in units of any integral multiple of 8 bits.
704 Allows to break when an Ada exception is handled.
709 Indicates that an exec system call was executed.
711 exec-events feature in qSupported
712 The qSupported packet allows GDB to request support for exec
713 events using the new 'gdbfeature' exec-event, and the qSupported
714 response can contain the corresponding 'stubfeature'. Set and
715 show commands can be used to display whether these features are enabled.
718 Equivalent to interrupting with the ^C character, but works in
721 thread created stop reason (T05 create:...)
722 Indicates that the thread was just created and is stopped at entry.
724 thread exit stop reply (w exitcode;tid)
725 Indicates that the thread has terminated.
728 Enables/disables thread create and exit event reporting. For
729 example, this is used in non-stop mode when GDB stops a set of
730 threads and synchronously waits for the their corresponding stop
731 replies. Without exit events, if one of the threads exits, GDB
732 would hang forever not knowing that it should no longer expect a
733 stop for that same thread.
736 Indicates that there are no resumed threads left in the target (all
737 threads are stopped). The remote stub reports support for this stop
738 reply to GDB's qSupported query.
741 Enables/disables catching syscalls from the inferior process.
742 The remote stub reports support for this packet to GDB's qSupported query.
744 syscall_entry stop reason
745 Indicates that a syscall was just called.
747 syscall_return stop reason
748 Indicates that a syscall just returned.
750 * Extended-remote exec events
752 ** GDB now has support for exec events on extended-remote Linux targets.
753 For such targets with Linux kernels 2.5.46 and later, this enables
754 follow-exec-mode and exec catchpoints.
756 set remote exec-event-feature-packet
757 show remote exec-event-feature-packet
758 Set/show the use of the remote exec event feature.
760 * Thread names in remote protocol
762 The reply to qXfer:threads:read may now include a name attribute for each
765 * Target remote mode fork and exec events
767 ** GDB now has support for fork and exec events on target remote mode
768 Linux targets. For such targets with Linux kernels 2.5.46 and later,
769 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
770 fork and exec catchpoints.
772 * Remote syscall events
774 ** GDB now has support for catch syscall on remote Linux targets,
775 currently enabled on x86/x86_64 architectures.
777 set remote catch-syscall-packet
778 show remote catch-syscall-packet
779 Set/show the use of the remote catch syscall feature.
783 ** The -var-set-format command now accepts the zero-hexadecimal
784 format. It outputs data in hexadecimal format with zero-padding on the
789 ** gdb.InferiorThread objects have a new attribute "global_num",
790 which refers to the thread's global thread ID. The existing
791 "num" attribute now refers to the thread's per-inferior number.
792 See "Per-inferior thread numbers" above.
793 ** gdb.InferiorThread objects have a new attribute "inferior", which
794 is the Inferior object the thread belongs to.
796 *** Changes in GDB 7.10
798 * Support for process record-replay and reverse debugging on aarch64*-linux*
799 targets has been added. GDB now supports recording of A64 instruction set
800 including advance SIMD instructions.
802 * Support for Sun's version of the "stabs" debug file format has been removed.
804 * GDB now honors the content of the file /proc/PID/coredump_filter
805 (PID is the process ID) on GNU/Linux systems. This file can be used
806 to specify the types of memory mappings that will be included in a
807 corefile. For more information, please refer to the manual page of
808 "core(5)". GDB also has a new command: "set use-coredump-filter
809 on|off". It allows to set whether GDB will read the content of the
810 /proc/PID/coredump_filter file when generating a corefile.
812 * The "info os" command on GNU/Linux can now display information on
814 "info os cpus" Listing of all cpus/cores on the system
816 * GDB has two new commands: "set serial parity odd|even|none" and
817 "show serial parity". These allows to set or show parity for the
820 * The "info source" command now displays the producer string if it was
821 present in the debug info. This typically includes the compiler version
822 and may include things like its command line arguments.
824 * The "info dll", an alias of the "info sharedlibrary" command,
825 is now available on all platforms.
827 * Directory names supplied to the "set sysroot" commands may be
828 prefixed with "target:" to tell GDB to access shared libraries from
829 the target system, be it local or remote. This replaces the prefix
830 "remote:". The default sysroot has been changed from "" to
831 "target:". "remote:" is automatically converted to "target:" for
832 backward compatibility.
834 * The system root specified by "set sysroot" will be prepended to the
835 filename of the main executable (if reported to GDB as absolute by
836 the operating system) when starting processes remotely, and when
837 attaching to already-running local or remote processes.
839 * GDB now supports automatic location and retrieval of executable
840 files from remote targets. Remote debugging can now be initiated
841 using only a "target remote" or "target extended-remote" command
842 (no "set sysroot" or "file" commands are required). See "New remote
845 * The "dump" command now supports verilog hex format.
847 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
849 * On GNU/Linux, GDB and gdbserver are now able to access executable
850 and shared library files without a "set sysroot" command when
851 attaching to processes running in different mount namespaces from
852 the debugger. This makes it possible to attach to processes in
853 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
854 See "New remote packets" below.
856 * The "tui reg" command now provides completion for all of the
857 available register groups, including target specific groups.
859 * The HISTSIZE environment variable is no longer read when determining
860 the size of GDB's command history. GDB now instead reads the dedicated
861 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
862 disables truncation of command history. Non-numeric values of GDBHISTSIZE
867 ** Memory ports can now be unbuffered.
871 ** gdb.Objfile objects have a new attribute "username",
872 which is the name of the objfile as specified by the user,
873 without, for example, resolving symlinks.
874 ** You can now write frame unwinders in Python.
875 ** gdb.Type objects have a new method "optimized_out",
876 returning optimized out gdb.Value instance of this type.
877 ** gdb.Value objects have new methods "reference_value" and
878 "const_value" which return a reference to the value and a
879 "const" version of the value respectively.
883 maint print symbol-cache
884 Print the contents of the symbol cache.
886 maint print symbol-cache-statistics
887 Print statistics of symbol cache usage.
889 maint flush-symbol-cache
890 Flush the contents of the symbol cache.
894 Start branch trace recording using Branch Trace Store (BTS) format.
897 Evaluate expression by using the compiler and print result.
901 Explicit commands for enabling and disabling tui mode.
904 set mpx bound on i386 and amd64
905 Support for bound table investigation on Intel MPX enabled applications.
909 Start branch trace recording using Intel Processor Trace format.
912 Print information about branch tracing internals.
914 maint btrace packet-history
915 Print the raw branch tracing data.
917 maint btrace clear-packet-history
918 Discard the stored raw branch tracing data.
921 Discard all branch tracing data. It will be fetched and processed
922 anew by the next "record" command.
927 Renamed from "set debug dwarf2-die".
929 Renamed from "show debug dwarf2-die".
932 Renamed from "set debug dwarf2-read".
933 show debug dwarf-read
934 Renamed from "show debug dwarf2-read".
936 maint set dwarf always-disassemble
937 Renamed from "maint set dwarf2 always-disassemble".
938 maint show dwarf always-disassemble
939 Renamed from "maint show dwarf2 always-disassemble".
941 maint set dwarf max-cache-age
942 Renamed from "maint set dwarf2 max-cache-age".
943 maint show dwarf max-cache-age
944 Renamed from "maint show dwarf2 max-cache-age".
947 show debug dwarf-line
948 Control display of debugging info regarding DWARF line processing.
952 Set the maximum number of candidates to be considered during
953 completion. The default value is 200. This limit allows GDB
954 to avoid generating large completion lists, the computation of
955 which can cause the debugger to become temporarily unresponsive.
957 set history remove-duplicates
958 show history remove-duplicates
959 Control the removal of duplicate history entries.
961 maint set symbol-cache-size
962 maint show symbol-cache-size
963 Control the size of the symbol cache.
965 set|show record btrace bts buffer-size
966 Set and show the size of the ring buffer used for branch tracing in
968 The obtained size may differ from the requested size. Use "info
969 record" to see the obtained buffer size.
971 set debug linux-namespaces
972 show debug linux-namespaces
973 Control display of debugging info regarding Linux namespaces.
975 set|show record btrace pt buffer-size
976 Set and show the size of the ring buffer used for branch tracing in
977 Intel Processor Trace format.
978 The obtained size may differ from the requested size. Use "info
979 record" to see the obtained buffer size.
981 maint set|show btrace pt skip-pad
982 Set and show whether PAD packets are skipped when computing the
985 * The command 'thread apply all' can now support new option '-ascending'
986 to call its specified command for all threads in ascending order.
988 * Python/Guile scripting
990 ** GDB now supports auto-loading of Python/Guile scripts contained in the
991 special section named `.debug_gdb_scripts'.
995 qXfer:btrace-conf:read
996 Return the branch trace configuration for the current thread.
998 Qbtrace-conf:bts:size
999 Set the requested ring buffer size for branch tracing in BTS format.
1002 Enable Intel Procesor Trace-based branch tracing for the current
1003 process. The remote stub reports support for this packet to GDB's
1006 Qbtrace-conf:pt:size
1007 Set the requested ring buffer size for branch tracing in Intel Processor
1011 Indicates a memory breakpoint instruction was executed, irrespective
1012 of whether it was GDB that planted the breakpoint or the breakpoint
1013 is hardcoded in the program. This is required for correct non-stop
1017 Indicates the target stopped for a hardware breakpoint. This is
1018 required for correct non-stop mode operation.
1021 Return information about files on the remote system.
1023 qXfer:exec-file:read
1024 Return the full absolute name of the file that was executed to
1025 create a process running on the remote system.
1028 Select the filesystem on which vFile: operations with filename
1029 arguments will operate. This is required for GDB to be able to
1030 access files on remote targets where the remote stub does not
1031 share a common filesystem with the inferior(s).
1034 Indicates that a fork system call was executed.
1037 Indicates that a vfork system call was executed.
1039 vforkdone stop reason
1040 Indicates that a vfork child of the specified process has executed
1041 an exec or exit, allowing the vfork parent to resume execution.
1043 fork-events and vfork-events features in qSupported
1044 The qSupported packet allows GDB to request support for fork and
1045 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1046 and the qSupported response can contain the corresponding
1047 'stubfeatures'. Set and show commands can be used to display
1048 whether these features are enabled.
1050 * Extended-remote fork events
1052 ** GDB now has support for fork events on extended-remote Linux
1053 targets. For targets with Linux kernels 2.5.60 and later, this
1054 enables follow-fork-mode and detach-on-fork for both fork and
1055 vfork, as well as fork and vfork catchpoints.
1057 * The info record command now shows the recording format and the
1058 branch tracing configuration for the current thread when using
1059 the btrace record target.
1060 For the BTS format, it shows the ring buffer size.
1062 * GDB now has support for DTrace USDT (Userland Static Defined
1063 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1065 * GDB now supports access to vector registers on S/390 GNU/Linux
1068 * Removed command line options
1070 -xdb HP-UX XDB compatibility mode.
1072 * Removed targets and native configurations
1074 HP/PA running HP-UX hppa*-*-hpux*
1075 Itanium running HP-UX ia64-*-hpux*
1077 * New configure options
1080 This configure option allows the user to build GDB with support for
1081 Intel Processor Trace (default: auto). This requires libipt.
1083 --with-libipt-prefix=PATH
1084 Specify the path to the version of libipt that GDB should use.
1085 $PATH/include should contain the intel-pt.h header and
1086 $PATH/lib should contain the libipt.so library.
1088 *** Changes in GDB 7.9.1
1092 ** Xmethods can now specify a result type.
1094 *** Changes in GDB 7.9
1096 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1100 ** You can now access frame registers from Python scripts.
1101 ** New attribute 'producer' for gdb.Symtab objects.
1102 ** gdb.Objfile objects have a new attribute "progspace",
1103 which is the gdb.Progspace object of the containing program space.
1104 ** gdb.Objfile objects have a new attribute "owner".
1105 ** gdb.Objfile objects have a new attribute "build_id",
1106 which is the build ID generated when the file was built.
1107 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1108 ** A new event "gdb.clear_objfiles" has been added, triggered when
1109 selecting a new file to debug.
1110 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1111 ** New function gdb.lookup_objfile.
1113 New events which are triggered when GDB modifies the state of the
1116 ** gdb.events.inferior_call_pre: Function call is about to be made.
1117 ** gdb.events.inferior_call_post: Function call has just been made.
1118 ** gdb.events.memory_changed: A memory location has been altered.
1119 ** gdb.events.register_changed: A register has been altered.
1121 * New Python-based convenience functions:
1123 ** $_caller_is(name [, number_of_frames])
1124 ** $_caller_matches(regexp [, number_of_frames])
1125 ** $_any_caller_is(name [, number_of_frames])
1126 ** $_any_caller_matches(regexp [, number_of_frames])
1128 * GDB now supports the compilation and injection of source code into
1129 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1130 to compile the source code to object code, and if successful, inject
1131 and execute that code within the current context of the inferior.
1132 Currently the C language is supported. The commands used to
1133 interface with this new feature are:
1135 compile code [-raw|-r] [--] [source code]
1136 compile file [-raw|-r] filename
1140 demangle [-l language] [--] name
1141 Demangle "name" in the specified language, or the current language
1142 if elided. This command is renamed from the "maint demangle" command.
1143 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1144 as "maint demangler-warning".
1146 queue-signal signal-name-or-number
1147 Queue a signal to be delivered to the thread when it is resumed.
1149 add-auto-load-scripts-directory directory
1150 Add entries to the list of directories from which to load auto-loaded
1153 maint print user-registers
1154 List all currently available "user" registers.
1156 compile code [-r|-raw] [--] [source code]
1157 Compile, inject, and execute in the inferior the executable object
1158 code produced by compiling the provided source code.
1160 compile file [-r|-raw] filename
1161 Compile and inject into the inferior the executable object code
1162 produced by compiling the source code stored in the filename
1165 * On resume, GDB now always passes the signal the program had stopped
1166 for to the thread the signal was sent to, even if the user changed
1167 threads before resuming. Previously GDB would often (but not
1168 always) deliver the signal to the thread that happens to be current
1171 * Conversely, the "signal" command now consistently delivers the
1172 requested signal to the current thread. GDB now asks for
1173 confirmation if the program had stopped for a signal and the user
1174 switched threads meanwhile.
1176 * "breakpoint always-inserted" modes "off" and "auto" merged.
1178 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1179 won't remove breakpoints from the target until all threads stop,
1180 even in non-stop mode. The "auto" mode has been removed, and "off"
1181 is now the default mode.
1185 set debug symbol-lookup
1186 show debug symbol-lookup
1187 Control display of debugging info regarding symbol lookup.
1191 ** The -list-thread-groups command outputs an exit-code field for
1192 inferiors that have exited.
1196 MIPS SDE mips*-sde*-elf*
1200 Support for these obsolete configurations has been removed.
1202 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1203 SGI Irix-5.x mips-*-irix5*
1204 SGI Irix-6.x mips-*-irix6*
1205 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1206 VAX running Ultrix vax-*-ultrix*
1208 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1209 and "assf"), have been removed. Use the "sharedlibrary" command, or
1210 its alias "share", instead.
1212 *** Changes in GDB 7.8
1214 * New command line options
1217 This is an alias for the --data-directory option.
1219 * GDB supports printing and modifying of variable length automatic arrays
1220 as specified in ISO C99.
1222 * The ARM simulator now supports instruction level tracing
1223 with or without disassembly.
1227 GDB now has support for scripting using Guile. Whether this is
1228 available is determined at configure time.
1229 Guile version 2.0 or greater is required.
1230 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1232 * New commands (for set/show, see "New options" below)
1236 Invoke CODE by passing it to the Guile interpreter.
1240 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1242 info auto-load guile-scripts [regexp]
1243 Print the list of automatically loaded Guile scripts.
1245 * The source command is now capable of sourcing Guile scripts.
1246 This feature is dependent on the debugger being built with Guile support.
1250 set print symbol-loading (off|brief|full)
1251 show print symbol-loading
1252 Control whether to print informational messages when loading symbol
1253 information for a file. The default is "full", but when debugging
1254 programs with large numbers of shared libraries the amount of output
1255 becomes less useful.
1257 set guile print-stack (none|message|full)
1258 show guile print-stack
1259 Show a stack trace when an error is encountered in a Guile script.
1261 set auto-load guile-scripts (on|off)
1262 show auto-load guile-scripts
1263 Control auto-loading of Guile script files.
1265 maint ada set ignore-descriptive-types (on|off)
1266 maint ada show ignore-descriptive-types
1267 Control whether the debugger should ignore descriptive types in Ada
1268 programs. The default is not to ignore the descriptive types. See
1269 the user manual for more details on descriptive types and the intended
1270 usage of this option.
1272 set auto-connect-native-target
1274 Control whether GDB is allowed to automatically connect to the
1275 native target for the run, attach, etc. commands when not connected
1276 to any target yet. See also "target native" below.
1278 set record btrace replay-memory-access (read-only|read-write)
1279 show record btrace replay-memory-access
1280 Control what memory accesses are allowed during replay.
1282 maint set target-async (on|off)
1283 maint show target-async
1284 This controls whether GDB targets operate in synchronous or
1285 asynchronous mode. Normally the default is asynchronous, if it is
1286 available; but this can be changed to more easily debug problems
1287 occurring only in synchronous mode.
1289 set mi-async (on|off)
1291 Control whether MI asynchronous mode is preferred. This supersedes
1292 "set target-async" of previous GDB versions.
1294 * "set target-async" is deprecated as a CLI option and is now an alias
1295 for "set mi-async" (only puts MI into async mode).
1297 * Background execution commands (e.g., "c&", "s&", etc.) are now
1298 possible ``out of the box'' if the target supports them. Previously
1299 the user would need to explicitly enable the possibility with the
1300 "set target-async on" command.
1302 * New features in the GDB remote stub, GDBserver
1304 ** New option --debug-format=option1[,option2,...] allows one to add
1305 additional text to each output. At present only timestamps
1306 are supported: --debug-format=timestamps.
1307 Timestamps can also be turned on with the
1308 "monitor set debug-format timestamps" command from GDB.
1310 * The 'record instruction-history' command now starts counting instructions
1311 at one. This also affects the instruction ranges reported by the
1312 'record function-call-history' command when given the /i modifier.
1314 * The command 'record function-call-history' supports a new modifier '/c' to
1315 indent the function names based on their call stack depth.
1316 The fields for the '/i' and '/l' modifier have been reordered.
1317 The source line range is now prefixed with 'at'.
1318 The instruction range is now prefixed with 'inst'.
1319 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1320 "record instruction-history" and "list" commands.
1322 * The ranges given as arguments to the 'record function-call-history' and
1323 'record instruction-history' commands are now inclusive.
1325 * The btrace record target now supports the 'record goto' command.
1326 For locations inside the execution trace, the back trace is computed
1327 based on the information stored in the execution trace.
1329 * The btrace record target supports limited reverse execution and replay.
1330 The target does not record data and therefore does not allow reading
1331 memory or registers.
1333 * The "catch syscall" command now works on s390*-linux* targets.
1335 * The "compare-sections" command is no longer specific to target
1336 remote. It now works with all targets.
1338 * All native targets are now consistently called "native".
1339 Consequently, the "target child", "target GNU", "target djgpp",
1340 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1341 commands have been replaced with "target native". The QNX/NTO port
1342 leaves the "procfs" target in place and adds a "native" target for
1343 consistency with other ports. The impact on users should be minimal
1344 as these commands previously either throwed an error, or were
1345 no-ops. The target's name is visible in the output of the following
1346 commands: "help target", "info target", "info files", "maint print
1349 * The "target native" command now connects to the native target. This
1350 can be used to launch native programs even when "set
1351 auto-connect-native-target" is set to off.
1353 * GDB now supports access to Intel MPX registers on GNU/Linux.
1355 * Support for Intel AVX-512 registers on GNU/Linux.
1356 Support displaying and modifying Intel AVX-512 registers
1357 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1359 * New remote packets
1361 qXfer:btrace:read's annex
1362 The qXfer:btrace:read packet supports a new annex 'delta' to read
1363 branch trace incrementally.
1367 ** Valid Python operations on gdb.Value objects representing
1368 structs/classes invoke the corresponding overloaded operators if
1370 ** New `Xmethods' feature in the Python API. Xmethods are
1371 additional methods or replacements for existing methods of a C++
1372 class. This feature is useful for those cases where a method
1373 defined in C++ source code could be inlined or optimized out by
1374 the compiler, making it unavailable to GDB.
1377 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1379 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1380 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1381 its alias "share", instead.
1383 * The commands "set remotebaud" and "show remotebaud" are no longer
1384 supported. Use "set serial baud" and "show serial baud" (respectively)
1389 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1390 target-async". The latter is left as a deprecated alias of the
1391 former for backward compatibility. If the target supports it,
1392 CLI background execution commands are now always possible by
1393 default, independently of whether the frontend stated a
1394 preference for asynchronous execution with "-gdb-set mi-async".
1395 Previously "-gdb-set target-async off" affected both MI execution
1396 commands and CLI execution commands.
1398 *** Changes in GDB 7.7
1400 * Improved support for process record-replay and reverse debugging on
1401 arm*-linux* targets. Support for thumb32 and syscall instruction
1402 recording has been added.
1404 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1406 * GDB now supports Fission DWP file format version 2.
1407 http://gcc.gnu.org/wiki/DebugFission
1409 * New convenience function "$_isvoid", to check whether an expression
1410 is void. A void expression is an expression where the type of the
1411 result is "void". For example, some convenience variables may be
1412 "void" when evaluated (e.g., "$_exitcode" before the execution of
1413 the program being debugged; or an undefined convenience variable).
1414 Another example, when calling a function whose return type is
1417 * The "maintenance print objfiles" command now takes an optional regexp.
1419 * The "catch syscall" command now works on arm*-linux* targets.
1421 * GDB now consistently shows "<not saved>" when printing values of
1422 registers the debug info indicates have not been saved in the frame
1423 and there's nowhere to retrieve them from
1424 (callee-saved/call-clobbered registers):
1429 (gdb) info registers rax
1432 Before, the former would print "<optimized out>", and the latter
1433 "*value not available*".
1435 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1440 ** Frame filters and frame decorators have been added.
1441 ** Temporary breakpoints are now supported.
1442 ** Line tables representation has been added.
1443 ** New attribute 'parent_type' for gdb.Field objects.
1444 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1445 ** New attribute 'name' for gdb.Type objects.
1449 Nios II ELF nios2*-*-elf
1450 Nios II GNU/Linux nios2*-*-linux
1451 Texas Instruments MSP430 msp430*-*-elf
1453 * Removed native configurations
1455 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1456 been removed. ELF variants of these configurations are kept supported.
1458 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1459 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1460 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1461 i[34567]86-*-openbsd3.[0-3]
1462 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1463 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1464 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1468 Like "catch throw", but catches a re-thrown exception.
1469 maint check-psymtabs
1470 Renamed from old "maint check-symtabs".
1472 Perform consistency checks on symtabs.
1473 maint expand-symtabs
1474 Expand symtabs matching an optional regexp.
1477 Display the details of GDB configure-time options.
1479 maint set|show per-command
1480 maint set|show per-command space
1481 maint set|show per-command time
1482 maint set|show per-command symtab
1483 Enable display of per-command gdb resource usage.
1485 remove-symbol-file FILENAME
1486 remove-symbol-file -a ADDRESS
1487 Remove a symbol file added via add-symbol-file. The file to remove
1488 can be identified by its filename or by an address that lies within
1489 the boundaries of this symbol file in memory.
1492 info exceptions REGEXP
1493 Display the list of Ada exceptions defined in the program being
1494 debugged. If provided, only the exceptions whose names match REGEXP
1499 set debug symfile off|on
1501 Control display of debugging info regarding reading symbol files and
1502 symbol tables within those files
1504 set print raw frame-arguments
1505 show print raw frame-arguments
1506 Set/show whether to print frame arguments in raw mode,
1507 disregarding any defined pretty-printers.
1509 set remote trace-status-packet
1510 show remote trace-status-packet
1511 Set/show the use of remote protocol qTStatus packet.
1515 Control display of debugging messages related to Nios II targets.
1519 Control whether target-assisted range stepping is enabled.
1521 set startup-with-shell
1522 show startup-with-shell
1523 Specifies whether Unix child processes are started via a shell or
1528 Use the target memory cache for accesses to the code segment. This
1529 improves performance of remote debugging (particularly disassembly).
1531 * You can now use a literal value 'unlimited' for options that
1532 interpret 0 or -1 as meaning "unlimited". E.g., "set
1533 trace-buffer-size unlimited" is now an alias for "set
1534 trace-buffer-size -1" and "set height unlimited" is now an alias for
1537 * The "set debug symtab-create" debugging option of GDB has been changed to
1538 accept a verbosity level. 0 means "off", 1 provides basic debugging
1539 output, and values of 2 or greater provides more verbose output.
1541 * New command-line options
1543 Display the details of GDB configure-time options.
1545 * The command 'tsave' can now support new option '-ctf' to save trace
1546 buffer in Common Trace Format.
1548 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1551 * GDB now implements the the C++ 'typeid' operator.
1553 * The new convenience variable $_exception holds the exception being
1554 thrown or caught at an exception-related catchpoint.
1556 * The exception-related catchpoints, like "catch throw", now accept a
1557 regular expression which can be used to filter exceptions by type.
1559 * The new convenience variable $_exitsignal is automatically set to
1560 the terminating signal number when the program being debugged dies
1561 due to an uncaught signal.
1565 ** All MI commands now accept an optional "--language" option.
1566 Support for this feature can be verified by using the "-list-features"
1567 command, which should contain "language-option".
1569 ** The new command -info-gdb-mi-command allows the user to determine
1570 whether a GDB/MI command is supported or not.
1572 ** The "^error" result record returned when trying to execute an undefined
1573 GDB/MI command now provides a variable named "code" whose content is the
1574 "undefined-command" error code. Support for this feature can be verified
1575 by using the "-list-features" command, which should contain
1576 "undefined-command-error-code".
1578 ** The -trace-save MI command can optionally save trace buffer in Common
1581 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1583 ** The command -data-list-register-values now accepts an optional
1584 "--skip-unavailable" option. When used, only the available registers
1587 ** The new command -trace-frame-collected dumps collected variables,
1588 computed expressions, tvars, memory and registers in a traceframe.
1590 ** The commands -stack-list-locals, -stack-list-arguments and
1591 -stack-list-variables now accept an option "--skip-unavailable".
1592 When used, only the available locals or arguments are displayed.
1594 ** The -exec-run command now accepts an optional "--start" option.
1595 When used, the command follows the same semantics as the "start"
1596 command, stopping the program's execution at the start of its
1597 main subprogram. Support for this feature can be verified using
1598 the "-list-features" command, which should contain
1599 "exec-run-start-option".
1601 ** The new commands -catch-assert and -catch-exceptions insert
1602 catchpoints stopping the program when Ada exceptions are raised.
1604 ** The new command -info-ada-exceptions provides the equivalent of
1605 the new "info exceptions" command.
1607 * New system-wide configuration scripts
1608 A GDB installation now provides scripts suitable for use as system-wide
1609 configuration scripts for the following systems:
1613 * GDB now supports target-assigned range stepping with remote targets.
1614 This improves the performance of stepping source lines by reducing
1615 the number of control packets from/to GDB. See "New remote packets"
1618 * GDB now understands the element 'tvar' in the XML traceframe info.
1619 It has the id of the collected trace state variables.
1621 * On S/390 targets that provide the transactional-execution feature,
1622 the program interruption transaction diagnostic block (TDB) is now
1623 represented as a number of additional "registers" in GDB.
1625 * New remote packets
1629 The vCont packet supports a new 'r' action, that tells the remote
1630 stub to step through an address range itself, without GDB
1631 involvemement at each single-step.
1633 qXfer:libraries-svr4:read's annex
1634 The previously unused annex of the qXfer:libraries-svr4:read packet
1635 is now used to support passing an argument list. The remote stub
1636 reports support for this argument list to GDB's qSupported query.
1637 The defined arguments are "start" and "prev", used to reduce work
1638 necessary for library list updating, resulting in significant
1641 * New features in the GDB remote stub, GDBserver
1643 ** GDBserver now supports target-assisted range stepping. Currently
1644 enabled on x86/x86_64 GNU/Linux targets.
1646 ** GDBserver now adds element 'tvar' in the XML in the reply to
1647 'qXfer:traceframe-info:read'. It has the id of the collected
1648 trace state variables.
1650 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1653 * New 'z' formatter for printing and examining memory, this displays the
1654 value as hexadecimal zero padded on the left to the size of the type.
1656 * GDB can now use Windows x64 unwinding data.
1658 * The "set remotebaud" command has been replaced by "set serial baud".
1659 Similarly, "show remotebaud" has been replaced by "show serial baud".
1660 The "set remotebaud" and "show remotebaud" commands are still available
1661 to provide backward compatibility with older versions of GDB.
1663 *** Changes in GDB 7.6
1665 * Target record has been renamed to record-full.
1666 Record/replay is now enabled with the "record full" command.
1667 This also affects settings that are associated with full record/replay
1668 that have been moved from "set/show record" to "set/show record full":
1670 set|show record full insn-number-max
1671 set|show record full stop-at-limit
1672 set|show record full memory-query
1674 * A new record target "record-btrace" has been added. The new target
1675 uses hardware support to record the control-flow of a process. It
1676 does not support replaying the execution, but it implements the
1677 below new commands for investigating the recorded execution log.
1678 This new recording method can be enabled using:
1682 The "record-btrace" target is only available on Intel Atom processors
1683 and requires a Linux kernel 2.6.32 or later.
1685 * Two new commands have been added for record/replay to give information
1686 about the recorded execution without having to replay the execution.
1687 The commands are only supported by "record btrace".
1689 record instruction-history prints the execution history at
1690 instruction granularity
1692 record function-call-history prints the execution history at
1693 function granularity
1695 * New native configurations
1697 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1698 FreeBSD/powerpc powerpc*-*-freebsd
1699 x86_64/Cygwin x86_64-*-cygwin*
1700 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1704 ARM AArch64 aarch64*-*-elf
1705 ARM AArch64 GNU/Linux aarch64*-*-linux
1706 Lynx 178 PowerPC powerpc-*-lynx*178
1707 x86_64/Cygwin x86_64-*-cygwin*
1708 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1710 * If the configured location of system.gdbinit file (as given by the
1711 --with-system-gdbinit option at configure time) is in the
1712 data-directory (as specified by --with-gdb-datadir at configure
1713 time) or in one of its subdirectories, then GDB will look for the
1714 system-wide init file in the directory specified by the
1715 --data-directory command-line option.
1717 * New command line options:
1719 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1720 other initialization files, unlike -nx which disables all of them.
1722 * Removed command line options
1724 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1727 * The 'ptype' and 'whatis' commands now accept an argument to control
1730 * 'info proc' now works on some core files.
1734 ** Vectors can be created with gdb.Type.vector.
1736 ** Python's atexit.register now works in GDB.
1738 ** Types can be pretty-printed via a Python API.
1740 ** Python 3 is now supported (in addition to Python 2.4 or later)
1742 ** New class gdb.Architecture exposes GDB's internal representation
1743 of architecture in the Python API.
1745 ** New method Frame.architecture returns the gdb.Architecture object
1746 corresponding to the frame's architecture.
1748 * New Python-based convenience functions:
1750 ** $_memeq(buf1, buf2, length)
1751 ** $_streq(str1, str2)
1753 ** $_regex(str, regex)
1755 * The 'cd' command now defaults to using '~' (the home directory) if not
1758 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1759 default for GCC since November 2000.
1761 * The command 'forward-search' can now be abbreviated as 'fo'.
1763 * The command 'info tracepoints' can now display 'installed on target'
1764 or 'not installed on target' for each non-pending location of tracepoint.
1766 * New configure options
1768 --enable-libmcheck/--disable-libmcheck
1769 By default, development versions are built with -lmcheck on hosts
1770 that support it, in order to help track memory corruption issues.
1771 Release versions, on the other hand, are built without -lmcheck
1772 by default. The --enable-libmcheck/--disable-libmcheck configure
1773 options allow the user to override that default.
1774 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1775 This configure option allows the user to build GDB with
1776 libbabeltrace using which GDB can read Common Trace Format data.
1778 * New commands (for set/show, see "New options" below)
1781 Catch signals. This is similar to "handle", but allows commands and
1782 conditions to be attached.
1785 List the BFDs known to GDB.
1787 python-interactive [command]
1789 Start a Python interactive prompt, or evaluate the optional command
1790 and print the result of expressions.
1793 "py" is a new alias for "python".
1795 enable type-printer [name]...
1796 disable type-printer [name]...
1797 Enable or disable type printers.
1801 ** For the Renesas Super-H architecture, the "regs" command has been removed
1802 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1807 set print type methods (on|off)
1808 show print type methods
1809 Control whether method declarations are displayed by "ptype".
1810 The default is to show them.
1812 set print type typedefs (on|off)
1813 show print type typedefs
1814 Control whether typedef definitions are displayed by "ptype".
1815 The default is to show them.
1817 set filename-display basename|relative|absolute
1818 show filename-display
1819 Control the way in which filenames is displayed.
1820 The default is "relative", which preserves previous behavior.
1822 set trace-buffer-size
1823 show trace-buffer-size
1824 Request target to change the size of trace buffer.
1826 set remote trace-buffer-size-packet auto|on|off
1827 show remote trace-buffer-size-packet
1828 Control the use of the remote protocol `QTBuffer:size' packet.
1832 Control display of debugging messages related to ARM AArch64.
1835 set debug coff-pe-read
1836 show debug coff-pe-read
1837 Control display of debugging messages related to reading of COFF/PE
1842 Control display of debugging messages related to Mach-O symbols
1845 set debug notification
1846 show debug notification
1847 Control display of debugging info for async remote notification.
1851 ** Command parameter changes are now notified using new async record
1852 "=cmd-param-changed".
1853 ** Trace frame changes caused by command "tfind" are now notified using
1854 new async record "=traceframe-changed".
1855 ** The creation, deletion and modification of trace state variables
1856 are now notified using new async records "=tsv-created",
1857 "=tsv-deleted" and "=tsv-modified".
1858 ** The start and stop of process record are now notified using new
1859 async record "=record-started" and "=record-stopped".
1860 ** Memory changes are now notified using new async record
1862 ** The data-disassemble command response will include a "fullname" field
1863 containing the absolute file name when source has been requested.
1864 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1865 command, to allow pattern filling of memory areas.
1866 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1867 library load/unload events.
1868 ** The response to breakpoint commands and breakpoint async records
1869 includes an "installed" field containing a boolean state about each
1870 non-pending tracepoint location is whether installed on target or not.
1871 ** Output of the "-trace-status" command includes a "trace-file" field
1872 containing the name of the trace file being examined. This field is
1873 optional, and only present when examining a trace file.
1874 ** The "fullname" field is now always present along with the "file" field,
1875 even if the file cannot be found by GDB.
1877 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1878 You must have the LZMA library available when configuring GDB for this
1879 feature to be enabled. For more information, see:
1880 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1882 * New remote packets
1885 Set the size of trace buffer. The remote stub reports support for this
1886 packet to gdb's qSupported query.
1889 Enable Branch Trace Store (BTS)-based branch tracing for the current
1890 thread. The remote stub reports support for this packet to gdb's
1894 Disable branch tracing for the current thread. The remote stub reports
1895 support for this packet to gdb's qSupported query.
1898 Read the traced branches for the current thread. The remote stub
1899 reports support for this packet to gdb's qSupported query.
1901 *** Changes in GDB 7.5
1903 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1904 for more x32 ABI info.
1906 * GDB now supports access to MIPS DSP registers on Linux targets.
1908 * GDB now supports debugging microMIPS binaries.
1910 * The "info os" command on GNU/Linux can now display information on
1911 several new classes of objects managed by the operating system:
1912 "info os procgroups" lists process groups
1913 "info os files" lists file descriptors
1914 "info os sockets" lists internet-domain sockets
1915 "info os shm" lists shared-memory regions
1916 "info os semaphores" lists semaphores
1917 "info os msg" lists message queues
1918 "info os modules" lists loaded kernel modules
1920 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1921 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1922 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1923 options and inspect the probe arguments using the new $_probe_arg family
1924 of convenience variables. You can obtain more information about SystemTap
1925 in <http://sourceware.org/systemtap/>.
1927 * GDB now supports reversible debugging on ARM, it allows you to
1928 debug basic ARM and THUMB instructions, and provides
1929 record/replay support.
1931 * The option "symbol-reloading" has been deleted as it is no longer used.
1935 ** GDB commands implemented in Python can now be put in command class
1938 ** The "maint set python print-stack on|off" is now deleted.
1940 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1941 apply "flag enum"-style pretty-printing to any enum.
1943 ** gdb.lookup_symbol can now work when there is no current frame.
1945 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1946 the source at which the symbol was defined.
1948 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1949 method 'value'. The former indicates whether the symbol needs a
1950 frame in order to compute its value, and the latter computes the
1953 ** A new method 'referenced_value' on gdb.Value objects which can
1954 dereference pointer as well as C++ reference values.
1956 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1957 which return the global and static blocks (as gdb.Block objects),
1958 of the underlying symbol table, respectively.
1960 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1961 object associated with a PC value.
1963 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1964 of the address range occupied by code for the current source line.
1966 * Go language support.
1967 GDB now supports debugging programs written in the Go programming
1970 * GDBserver now supports stdio connections.
1971 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1973 * The binary "gdbtui" can no longer be built or installed.
1974 Use "gdb -tui" instead.
1976 * GDB will now print "flag" enums specially. A flag enum is one where
1977 all the enumerator values have no bits in common when pairwise
1978 "and"ed. When printing a value whose type is a flag enum, GDB will
1979 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1980 (gdb) print (enum E) 3
1983 * The filename part of a linespec will now match trailing components
1984 of a source file name. For example, "break gcc/expr.c:1000" will
1985 now set a breakpoint in build/gcc/expr.c, but not
1986 build/libcpp/expr.c.
1988 * The "info proc" and "generate-core-file" commands will now also
1989 work on remote targets connected to GDBserver on Linux.
1991 * The command "info catch" has been removed. It has been disabled
1992 since December 2007.
1994 * The "catch exception" and "catch assert" commands now accept
1995 a condition at the end of the command, much like the "break"
1996 command does. For instance:
1998 (gdb) catch exception Constraint_Error if Barrier = True
2000 Previously, it was possible to add a condition to such catchpoints,
2001 but it had to be done as a second step, after the catchpoint had been
2002 created, using the "condition" command.
2004 * The "info static-tracepoint-marker" command will now also work on
2005 native Linux targets with in-process agent.
2007 * GDB can now set breakpoints on inlined functions.
2009 * The .gdb_index section has been updated to include symbols for
2010 inlined functions. GDB will ignore older .gdb_index sections by
2011 default, which could cause symbol files to be loaded more slowly
2012 until their .gdb_index sections can be recreated. The new command
2013 "set use-deprecated-index-sections on" will cause GDB to use any older
2014 .gdb_index sections it finds. This will restore performance, but the
2015 ability to set breakpoints on inlined functions will be lost in symbol
2016 files with older .gdb_index sections.
2018 The .gdb_index section has also been updated to record more information
2019 about each symbol. This speeds up the "info variables", "info functions"
2020 and "info types" commands when used with programs having the .gdb_index
2021 section, as well as speeding up debugging with shared libraries using
2022 the .gdb_index section.
2024 * Ada support for GDB/MI Variable Objects has been added.
2026 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2031 ** New command -info-os is the MI equivalent of "info os".
2033 ** Output logs ("set logging" and related) now include MI output.
2037 ** "set use-deprecated-index-sections on|off"
2038 "show use-deprecated-index-sections on|off"
2039 Controls the use of deprecated .gdb_index sections.
2041 ** "catch load" and "catch unload" can be used to stop when a shared
2042 library is loaded or unloaded, respectively.
2044 ** "enable count" can be used to auto-disable a breakpoint after
2047 ** "info vtbl" can be used to show the virtual method tables for
2048 C++ and Java objects.
2050 ** "explore" and its sub commands "explore value" and "explore type"
2051 can be used to recursively explore values and types of
2052 expressions. These commands are available only if GDB is
2053 configured with '--with-python'.
2055 ** "info auto-load" shows status of all kinds of auto-loaded files,
2056 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2057 sequences of commands files, "info auto-load python-scripts"
2058 shows status of auto-loading Python script files,
2059 "info auto-load local-gdbinit" shows status of loading init file
2060 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2061 status of inferior specific thread debugging shared library loading.
2063 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2064 and "show auto-load-scripts" commands have been deprecated, use their
2065 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2066 and "show auto-load python-scripts" counterparts instead.
2068 ** "dprintf location,format,args..." creates a dynamic printf, which
2069 is basically a breakpoint that does a printf and immediately
2070 resumes your program's execution, so it is like a printf that you
2071 can insert dynamically at runtime instead of at compiletime.
2073 ** "set print symbol"
2075 Controls whether GDB attempts to display the symbol, if any,
2076 corresponding to addresses it prints. This defaults to "on", but
2077 you can set it to "off" to restore GDB's previous behavior.
2079 * Deprecated commands
2081 ** For the Renesas Super-H architecture, the "regs" command has been
2082 deprecated, and "info all-registers" should be used instead.
2086 Renesas RL78 rl78-*-elf
2087 HP OpenVMS ia64 ia64-hp-openvms*
2089 * GDBserver supports evaluation of breakpoint conditions. When
2090 support is advertised by GDBserver, GDB may be told to send the
2091 breakpoint conditions in bytecode form to GDBserver. GDBserver
2092 will only report the breakpoint trigger to GDB when its condition
2097 set mips compression
2098 show mips compression
2099 Select the compressed ISA encoding used in functions that have no symbol
2100 information available. The encoding can be set to either of:
2103 and is updated automatically from ELF file flags if available.
2105 set breakpoint condition-evaluation
2106 show breakpoint condition-evaluation
2107 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2108 GDBserver ("target"). Default option "auto" chooses the most efficient
2110 This option can improve debugger efficiency depending on the speed of the
2114 Disable auto-loading globally.
2117 Show auto-loading setting of all kinds of auto-loaded files.
2119 set auto-load gdb-scripts on|off
2120 show auto-load gdb-scripts
2121 Control auto-loading of GDB canned sequences of commands files.
2123 set auto-load python-scripts on|off
2124 show auto-load python-scripts
2125 Control auto-loading of Python script files.
2127 set auto-load local-gdbinit on|off
2128 show auto-load local-gdbinit
2129 Control loading of init file (.gdbinit) from current directory.
2131 set auto-load libthread-db on|off
2132 show auto-load libthread-db
2133 Control auto-loading of inferior specific thread debugging shared library.
2135 set auto-load scripts-directory <dir1>[:<dir2>...]
2136 show auto-load scripts-directory
2137 Set a list of directories from which to load auto-loaded scripts.
2138 Automatically loaded Python scripts and GDB scripts are located in one
2139 of the directories listed by this option.
2140 The delimiter (':' above) may differ according to the host platform.
2142 set auto-load safe-path <dir1>[:<dir2>...]
2143 show auto-load safe-path
2144 Set a list of directories from which it is safe to auto-load files.
2145 The delimiter (':' above) may differ according to the host platform.
2147 set debug auto-load on|off
2148 show debug auto-load
2149 Control display of debugging info for auto-loading the files above.
2151 set dprintf-style gdb|call|agent
2153 Control the way in which a dynamic printf is performed; "gdb"
2154 requests a GDB printf command, while "call" causes dprintf to call a
2155 function in the inferior. "agent" requests that the target agent
2156 (such as GDBserver) do the printing.
2158 set dprintf-function <expr>
2159 show dprintf-function
2160 set dprintf-channel <expr>
2161 show dprintf-channel
2162 Set the function and optional first argument to the call when using
2163 the "call" style of dynamic printf.
2165 set disconnected-dprintf on|off
2166 show disconnected-dprintf
2167 Control whether agent-style dynamic printfs continue to be in effect
2168 after GDB disconnects.
2170 * New configure options
2172 --with-auto-load-dir
2173 Configure default value for the 'set auto-load scripts-directory'
2174 setting above. It defaults to '$debugdir:$datadir/auto-load',
2175 $debugdir representing global debugging info directories (available
2176 via 'show debug-file-directory') and $datadir representing GDB's data
2177 directory (available via 'show data-directory').
2179 --with-auto-load-safe-path
2180 Configure default value for the 'set auto-load safe-path' setting
2181 above. It defaults to the --with-auto-load-dir setting.
2183 --without-auto-load-safe-path
2184 Set 'set auto-load safe-path' to '/', effectively disabling this
2187 * New remote packets
2189 z0/z1 conditional breakpoints extension
2191 The z0/z1 breakpoint insertion packets have been extended to carry
2192 a list of conditional expressions over to the remote stub depending on the
2193 condition evaluation mode. The use of this extension can be controlled
2194 via the "set remote conditional-breakpoints-packet" command.
2198 Specify the signals which the remote stub may pass to the debugged
2199 program without GDB involvement.
2201 * New command line options
2203 --init-command=FILE, -ix Like --command, -x but execute it
2204 before loading inferior.
2205 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2206 execute it before loading inferior.
2208 *** Changes in GDB 7.4
2210 * GDB now handles ambiguous linespecs more consistently; the existing
2211 FILE:LINE support has been expanded to other types of linespecs. A
2212 breakpoint will now be set on all matching locations in all
2213 inferiors, and locations will be added or removed according to
2216 * GDB now allows you to skip uninteresting functions and files when
2217 stepping with the "skip function" and "skip file" commands.
2219 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2220 and "show remote hardware-watchpoint-length-limit". These allows to
2221 set or show the maximum length limit (in bytes) of a remote
2222 target hardware watchpoint.
2224 This allows e.g. to use "unlimited" hardware watchpoints with the
2225 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2226 watchpoints are slower than real hardware watchpoints but are
2227 significantly faster than gdb software watchpoints.
2231 ** The register_pretty_printer function in module gdb.printing now takes
2232 an optional `replace' argument. If True, the new printer replaces any
2235 ** The "maint set python print-stack on|off" command has been
2236 deprecated and will be deleted in GDB 7.5.
2237 A new command: "set python print-stack none|full|message" has
2238 replaced it. Additionally, the default for "print-stack" is
2239 now "message", which just prints the error message without
2242 ** A prompt substitution hook (prompt_hook) is now available to the
2245 ** A new Python module, gdb.prompt has been added to the GDB Python
2246 modules library. This module provides functionality for
2247 escape sequences in prompts (used by set/show
2248 extended-prompt). These escape sequences are replaced by their
2249 corresponding value.
2251 ** Python commands and convenience-functions located in
2252 'data-directory'/python/gdb/command and
2253 'data-directory'/python/gdb/function are now automatically loaded
2256 ** Blocks now provide four new attributes. global_block and
2257 static_block will return the global and static blocks
2258 respectively. is_static and is_global are boolean attributes
2259 that indicate if the block is one of those two types.
2261 ** Symbols now provide the "type" attribute, the type of the symbol.
2263 ** The "gdb.breakpoint" function has been deprecated in favor of
2266 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2267 of a function. This class is based on the "finish" command
2268 available in the CLI.
2270 ** Type objects for struct and union types now allow access to
2271 the fields using standard Python dictionary (mapping) methods.
2272 For example, "some_type['myfield']" now works, as does
2273 "some_type.items()".
2275 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2278 ** A new function, "deep_items" has been added to the gdb.types
2279 module in the GDB Python modules library. This function returns
2280 an iterator over the fields of a struct or union type. Unlike
2281 the standard Python "iteritems" method, it will recursively traverse
2282 any anonymous fields.
2286 ** "*stopped" events can report several new "reason"s, such as
2289 ** Breakpoint changes are now notified using new async records, like
2290 "=breakpoint-modified".
2292 ** New command -ada-task-info.
2294 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2295 $sdir specifies the default system locations of shared libraries.
2296 $pdir specifies the directory where the libpthread used by the application
2299 GDB no longer looks in $sdir and $pdir after it has searched the directories
2300 mentioned in libthread-db-search-path. If you want to search those
2301 directories, they must be specified in libthread-db-search-path.
2302 The default value of libthread-db-search-path on GNU/Linux and Solaris
2303 systems is now "$sdir:$pdir".
2305 $pdir is not supported by gdbserver, it is currently ignored.
2306 $sdir is supported by gdbserver.
2308 * New configure option --with-iconv-bin.
2309 When using the internationalization support like the one in the GNU C
2310 library, GDB will invoke the "iconv" program to get a list of supported
2311 character sets. If this program lives in a non-standard location, one can
2312 use this option to specify where to find it.
2314 * When natively debugging programs on PowerPC BookE processors running
2315 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2316 watchpoints, which specify a mask in addition to an address to watch.
2317 The mask specifies that some bits of an address (the bits which are
2318 reset in the mask) should be ignored when matching the address accessed
2319 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2320 section in the user manual for more details.
2322 * The new option --once causes GDBserver to stop listening for connections once
2323 the first connection is made. The listening port used by GDBserver will
2324 become available after that.
2326 * New commands "info macros" and "alias" have been added.
2328 * New function parameters suffix @entry specifies value of function parameter
2329 at the time the function got called. Entry values are available only since
2335 "!" is now an alias of the "shell" command.
2336 Note that no space is needed between "!" and SHELL COMMAND.
2340 watch EXPRESSION mask MASK_VALUE
2341 The watch command now supports the mask argument which allows creation
2342 of masked watchpoints, if the current architecture supports this feature.
2344 info auto-load-scripts [REGEXP]
2345 This command was formerly named "maintenance print section-scripts".
2346 It is now generally useful and is no longer a maintenance-only command.
2348 info macro [-all] [--] MACRO
2349 The info macro command has new options `-all' and `--'. The first for
2350 printing all definitions of a macro. The second for explicitly specifying
2351 the end of arguments and the beginning of the macro name in case the macro
2352 name starts with a hyphen.
2354 collect[/s] EXPRESSIONS
2355 The tracepoint collect command now takes an optional modifier "/s"
2356 that directs it to dereference pointer-to-character types and
2357 collect the bytes of memory up to a zero byte. The behavior is
2358 similar to what you see when you use the regular print command on a
2359 string. An optional integer following the "/s" sets a bound on the
2360 number of bytes that will be collected.
2363 The trace start command now interprets any supplied arguments as a
2364 note to be recorded with the trace run, with an effect similar to
2365 setting the variable trace-notes.
2368 The trace stop command now interprets any arguments as a note to be
2369 mentioned along with the tstatus report that the trace was stopped
2370 with a command. The effect is similar to setting the variable
2373 * Tracepoints can now be enabled and disabled at any time after a trace
2374 experiment has been started using the standard "enable" and "disable"
2375 commands. It is now possible to start a trace experiment with no enabled
2376 tracepoints; GDB will display a warning, but will allow the experiment to
2377 begin, assuming that tracepoints will be enabled as needed while the trace
2380 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2381 locations with 4-byte instructions, when they were previously
2382 limited to locations with instructions of 5 bytes or longer.
2386 set debug dwarf2-read
2387 show debug dwarf2-read
2388 Turns on or off display of debugging messages related to reading
2389 DWARF debug info. The default is off.
2391 set debug symtab-create
2392 show debug symtab-create
2393 Turns on or off display of debugging messages related to symbol table
2394 creation. The default is off.
2397 show extended-prompt
2398 Set the GDB prompt, and allow escape sequences to be inserted to
2399 display miscellaneous information (see 'help set extended-prompt'
2400 for the list of sequences). This prompt (and any information
2401 accessed through the escape sequences) is updated every time the
2402 prompt is displayed.
2404 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2405 show print entry-values
2406 Set printing of frame argument values at function entry. In some cases
2407 GDB can determine the value of function argument which was passed by the
2408 function caller, even if the value was modified inside the called function.
2410 set debug entry-values
2411 show debug entry-values
2412 Control display of debugging info for determining frame argument values at
2413 function entry and virtual tail call frames.
2415 set basenames-may-differ
2416 show basenames-may-differ
2417 Set whether a source file may have multiple base names.
2418 (A "base name" is the name of a file with the directory part removed.
2419 Example: The base name of "/home/user/hello.c" is "hello.c".)
2420 If set, GDB will canonicalize file names (e.g., expand symlinks)
2421 before comparing them. Canonicalization is an expensive operation,
2422 but it allows the same file be known by more than one base name.
2423 If not set (the default), all source files are assumed to have just
2424 one base name, and gdb will do file name comparisons more efficiently.
2430 Set a user name and notes for the current and any future trace runs.
2431 This is useful for long-running and/or disconnected traces, to
2432 inform others (or yourself) as to who is running the trace, supply
2433 contact information, or otherwise explain what is going on.
2435 set trace-stop-notes
2436 show trace-stop-notes
2437 Set a note attached to the trace run, that is displayed when the
2438 trace has been stopped by a tstop command. This is useful for
2439 instance as an explanation, if you are stopping a trace run that was
2440 started by someone else.
2442 * New remote packets
2446 Dynamically enable a tracepoint in a started trace experiment.
2450 Dynamically disable a tracepoint in a started trace experiment.
2454 Set the user and notes of the trace run.
2458 Query the current status of a tracepoint.
2462 Query the minimum length of instruction at which a fast tracepoint may
2465 * Dcache size (number of lines) and line-size are now runtime-configurable
2466 via "set dcache line" and "set dcache line-size" commands.
2470 Texas Instruments TMS320C6x tic6x-*-*
2474 Renesas RL78 rl78-*-elf
2476 *** Changes in GDB 7.3.1
2478 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2480 *** Changes in GDB 7.3
2482 * GDB has a new command: "thread find [REGEXP]".
2483 It finds the thread id whose name, target id, or thread extra info
2484 matches the given regular expression.
2486 * The "catch syscall" command now works on mips*-linux* targets.
2488 * The -data-disassemble MI command now supports modes 2 and 3 for
2489 dumping the instruction opcodes.
2491 * New command line options
2493 -data-directory DIR Specify DIR as the "data-directory".
2494 This is mostly for testing purposes.
2496 * The "maint set python auto-load on|off" command has been renamed to
2497 "set auto-load-scripts on|off".
2499 * GDB has a new command: "set directories".
2500 It is like the "dir" command except that it replaces the
2501 source path list instead of augmenting it.
2503 * GDB now understands thread names.
2505 On GNU/Linux, "info threads" will display the thread name as set by
2506 prctl or pthread_setname_np.
2508 There is also a new command, "thread name", which can be used to
2509 assign a name internally for GDB to display.
2512 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2513 has been integrated into GDB.
2517 ** The function gdb.Write now accepts an optional keyword 'stream'.
2518 This keyword, when provided, will direct the output to either
2519 stdout, stderr, or GDB's logging output.
2521 ** Parameters can now be be sub-classed in Python, and in particular
2522 you may implement the get_set_doc and get_show_doc functions.
2523 This improves how Parameter set/show documentation is processed
2524 and allows for more dynamic content.
2526 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2527 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2528 have an is_valid method.
2530 ** Breakpoints can now be sub-classed in Python, and in particular
2531 you may implement a 'stop' function that is executed each time
2532 the inferior reaches that breakpoint.
2534 ** New function gdb.lookup_global_symbol looks up a global symbol.
2536 ** GDB values in Python are now callable if the value represents a
2537 function. For example, if 'some_value' represents a function that
2538 takes two integer parameters and returns a value, you can call
2539 that function like so:
2541 result = some_value (10,20)
2543 ** Module gdb.types has been added.
2544 It contains a collection of utilities for working with gdb.Types objects:
2545 get_basic_type, has_field, make_enum_dict.
2547 ** Module gdb.printing has been added.
2548 It contains utilities for writing and registering pretty-printers.
2549 New classes: PrettyPrinter, SubPrettyPrinter,
2550 RegexpCollectionPrettyPrinter.
2551 New function: register_pretty_printer.
2553 ** New commands "info pretty-printers", "enable pretty-printer" and
2554 "disable pretty-printer" have been added.
2556 ** gdb.parameter("directories") is now available.
2558 ** New function gdb.newest_frame returns the newest frame in the
2561 ** The gdb.InferiorThread class has a new "name" attribute. This
2562 holds the thread's name.
2564 ** Python Support for Inferior events.
2565 Python scripts can add observers to be notified of events
2566 occurring in the process being debugged.
2567 The following events are currently supported:
2568 - gdb.events.cont Continue event.
2569 - gdb.events.exited Inferior exited event.
2570 - gdb.events.stop Signal received, and Breakpoint hit events.
2574 ** GDB now puts template parameters in scope when debugging in an
2575 instantiation. For example, if you have:
2577 template<int X> int func (void) { return X; }
2579 then if you step into func<5>, "print X" will show "5". This
2580 feature requires proper debuginfo support from the compiler; it
2581 was added to GCC 4.5.
2583 ** The motion commands "next", "finish", "until", and "advance" now
2584 work better when exceptions are thrown. In particular, GDB will
2585 no longer lose control of the inferior; instead, the GDB will
2586 stop the inferior at the point at which the exception is caught.
2587 This functionality requires a change in the exception handling
2588 code that was introduced in GCC 4.5.
2590 * GDB now follows GCC's rules on accessing volatile objects when
2591 reading or writing target state during expression evaluation.
2592 One notable difference to prior behavior is that "print x = 0"
2593 no longer generates a read of x; the value of the assignment is
2594 now always taken directly from the value being assigned.
2596 * GDB now has some support for using labels in the program's source in
2597 linespecs. For instance, you can use "advance label" to continue
2598 execution to a label.
2600 * GDB now has support for reading and writing a new .gdb_index
2601 section. This section holds a fast index of DWARF debugging
2602 information and can be used to greatly speed up GDB startup and
2603 operation. See the documentation for `save gdb-index' for details.
2605 * The "watch" command now accepts an optional "-location" argument.
2606 When used, this causes GDB to watch the memory referred to by the
2607 expression. Such a watchpoint is never deleted due to it going out
2610 * GDB now supports thread debugging of core dumps on GNU/Linux.
2612 GDB now activates thread debugging using the libthread_db library
2613 when debugging GNU/Linux core dumps, similarly to when debugging
2614 live processes. As a result, when debugging a core dump file, GDB
2615 is now able to display pthread_t ids of threads. For example, "info
2616 threads" shows the same output as when debugging the process when it
2617 was live. In earlier releases, you'd see something like this:
2620 * 1 LWP 6780 main () at main.c:10
2622 While now you see this:
2625 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2627 It is also now possible to inspect TLS variables when debugging core
2630 When debugging a core dump generated on a machine other than the one
2631 used to run GDB, you may need to point GDB at the correct
2632 libthread_db library with the "set libthread-db-search-path"
2633 command. See the user manual for more details on this command.
2635 * When natively debugging programs on PowerPC BookE processors running
2636 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2637 which stop execution of the inferior whenever it executes an instruction
2638 at any address within the specified range. See the "PowerPC Embedded"
2639 section in the user manual for more details.
2641 * New features in the GDB remote stub, GDBserver
2643 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2644 and i686 LynxOS (version 5.x).
2646 ** GDBserver is now supported on Blackfin Linux.
2648 * New native configurations
2650 ia64 HP-UX ia64-*-hpux*
2654 Analog Devices, Inc. Blackfin Processor bfin-*
2656 * Ada task switching is now supported on sparc-elf targets when
2657 debugging a program using the Ravenscar Profile. For more information,
2658 see the "Tasking Support when using the Ravenscar Profile" section
2659 in the GDB user manual.
2661 * Guile support was removed.
2663 * New features in the GNU simulator
2665 ** The --map-info flag lists all known core mappings.
2667 ** CFI flashes may be simulated via the "cfi" device.
2669 *** Changes in GDB 7.2
2671 * Shared library support for remote targets by default
2673 When GDB is configured for a generic, non-OS specific target, like
2674 for example, --target=arm-eabi or one of the many *-*-elf targets,
2675 GDB now queries remote stubs for loaded shared libraries using the
2676 `qXfer:libraries:read' packet. Previously, shared library support
2677 was always disabled for such configurations.
2681 ** Argument Dependent Lookup (ADL)
2683 In C++ ADL lookup directs function search to the namespaces of its
2684 arguments even if the namespace has not been imported.
2694 Here the compiler will search for `foo' in the namespace of 'b'
2695 and find A::foo. GDB now supports this. This construct is commonly
2696 used in the Standard Template Library for operators.
2698 ** Improved User Defined Operator Support
2700 In addition to member operators, GDB now supports lookup of operators
2701 defined in a namespace and imported with a `using' directive, operators
2702 defined in the global scope, operators imported implicitly from an
2703 anonymous namespace, and the ADL operators mentioned in the previous
2705 GDB now also supports proper overload resolution for all the previously
2706 mentioned flavors of operators.
2708 ** static const class members
2710 Printing of static const class members that are initialized in the
2711 class definition has been fixed.
2713 * Windows Thread Information Block access.
2715 On Windows targets, GDB now supports displaying the Windows Thread
2716 Information Block (TIB) structure. This structure is visible either
2717 by using the new command `info w32 thread-information-block' or, by
2718 dereferencing the new convenience variable named `$_tlb', a
2719 thread-specific pointer to the TIB. This feature is also supported
2720 when remote debugging using GDBserver.
2722 * Static tracepoints
2724 Static tracepoints are calls in the user program into a tracing
2725 library. One such library is a port of the LTTng kernel tracer to
2726 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2727 When debugging with GDBserver, GDB now supports combining the GDB
2728 tracepoint machinery with such libraries. For example: the user can
2729 use GDB to probe a static tracepoint marker (a call from the user
2730 program into the tracing library) with the new "strace" command (see
2731 "New commands" below). This creates a "static tracepoint" in the
2732 breakpoint list, that can be manipulated with the same feature set
2733 as fast and regular tracepoints. E.g., collect registers, local and
2734 global variables, collect trace state variables, and define
2735 tracepoint conditions. In addition, the user can collect extra
2736 static tracepoint marker specific data, by collecting the new
2737 $_sdata internal variable. When analyzing the trace buffer, you can
2738 inspect $_sdata like any other variable available to GDB. For more
2739 information, see the "Tracepoints" chapter in GDB user manual. New
2740 remote packets have been defined to support static tracepoints, see
2741 the "New remote packets" section below.
2743 * Better reconstruction of tracepoints after disconnected tracing
2745 GDB will attempt to download the original source form of tracepoint
2746 definitions when starting a trace run, and then will upload these
2747 upon reconnection to the target, resulting in a more accurate
2748 reconstruction of the tracepoints that are in use on the target.
2752 You can now exercise direct control over the ways that GDB can
2753 affect your program. For instance, you can disallow the setting of
2754 breakpoints, so that the program can run continuously (assuming
2755 non-stop mode). In addition, the "observer" variable is available
2756 to switch all of the different controls; in observer mode, GDB
2757 cannot affect the target's behavior at all, which is useful for
2758 tasks like diagnosing live systems in the field.
2760 * The new convenience variable $_thread holds the number of the
2763 * New remote packets
2767 Return the address of the Windows Thread Information Block of a given thread.
2771 In response to several of the tracepoint packets, the target may now
2772 also respond with a number of intermediate `qRelocInsn' request
2773 packets before the final result packet, to have GDB handle
2774 relocating an instruction to execute at a different address. This
2775 is particularly useful for stubs that support fast tracepoints. GDB
2776 reports support for this feature in the qSupported packet.
2780 List static tracepoint markers in the target program.
2784 List static tracepoint markers at a given address in the target
2787 qXfer:statictrace:read
2789 Read the static trace data collected (by a `collect $_sdata'
2790 tracepoint action). The remote stub reports support for this packet
2791 to gdb's qSupported query.
2795 Send the current settings of GDB's permission flags.
2799 Send part of the source (textual) form of a tracepoint definition,
2800 which includes location, conditional, and action list.
2802 * The source command now accepts a -s option to force searching for the
2803 script in the source search path even if the script name specifies
2806 * New features in the GDB remote stub, GDBserver
2808 - GDBserver now support tracepoints (including fast tracepoints, and
2809 static tracepoints). The feature is currently supported by the
2810 i386-linux and amd64-linux builds. See the "Tracepoints support
2811 in gdbserver" section in the manual for more information.
2813 GDBserver JIT compiles the tracepoint's conditional agent
2814 expression bytecode into native code whenever possible for low
2815 overhead dynamic tracepoints conditionals. For such tracepoints,
2816 an expression that examines program state is evaluated when the
2817 tracepoint is reached, in order to determine whether to capture
2818 trace data. If the condition is simple and false, processing the
2819 tracepoint finishes very quickly and no data is gathered.
2821 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2822 for static tracepoints support.
2824 - GDBserver now supports x86_64 Windows 64-bit debugging.
2826 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2827 it understands register description.
2829 * The --batch flag now disables pagination and queries.
2831 * X86 general purpose registers
2833 GDB now supports reading/writing byte, word and double-word x86
2834 general purpose registers directly. This means you can use, say,
2835 $ah or $ax to refer, respectively, to the byte register AH and
2836 16-bit word register AX that are actually portions of the 32-bit
2837 register EAX or 64-bit register RAX.
2839 * The `commands' command now accepts a range of breakpoints to modify.
2840 A plain `commands' following a command that creates multiple
2841 breakpoints affects all the breakpoints set by that command. This
2842 applies to breakpoints set by `rbreak', and also applies when a
2843 single `break' command creates multiple breakpoints (e.g.,
2844 breakpoints on overloaded c++ functions).
2846 * The `rbreak' command now accepts a filename specification as part of
2847 its argument, limiting the functions selected by the regex to those
2848 in the specified file.
2850 * Support for remote debugging Windows and SymbianOS shared libraries
2851 from Unix hosts has been improved. Non Windows GDB builds now can
2852 understand target reported file names that follow MS-DOS based file
2853 system semantics, such as file names that include drive letters and
2854 use the backslash character as directory separator. This makes it
2855 possible to transparently use the "set sysroot" and "set
2856 solib-search-path" on Unix hosts to point as host copies of the
2857 target's shared libraries. See the new command "set
2858 target-file-system-kind" described below, and the "Commands to
2859 specify files" section in the user manual for more information.
2863 eval template, expressions...
2864 Convert the values of one or more expressions under the control
2865 of the string template to a command line, and call it.
2867 set target-file-system-kind unix|dos-based|auto
2868 show target-file-system-kind
2869 Set or show the assumed file system kind for target reported file
2872 save breakpoints <filename>
2873 Save all current breakpoint definitions to a file suitable for use
2874 in a later debugging session. To read the saved breakpoint
2875 definitions, use the `source' command.
2877 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2880 info static-tracepoint-markers
2881 Display information about static tracepoint markers in the target.
2883 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2884 Define a static tracepoint by probing a marker at the given
2885 function, line, address, or marker ID.
2889 Enable and disable observer mode.
2891 set may-write-registers on|off
2892 set may-write-memory on|off
2893 set may-insert-breakpoints on|off
2894 set may-insert-tracepoints on|off
2895 set may-insert-fast-tracepoints on|off
2896 set may-interrupt on|off
2897 Set individual permissions for GDB effects on the target. Note that
2898 some of these settings can have undesirable or surprising
2899 consequences, particularly when changed in the middle of a session.
2900 For instance, disabling the writing of memory can prevent
2901 breakpoints from being inserted, cause single-stepping to fail, or
2902 even crash your program, if you disable after breakpoints have been
2903 inserted. However, GDB should not crash.
2905 set record memory-query on|off
2906 show record memory-query
2907 Control whether to stop the inferior if memory changes caused
2908 by an instruction cannot be recorded.
2913 The disassemble command now supports "start,+length" form of two arguments.
2917 ** GDB now provides a new directory location, called the python directory,
2918 where Python scripts written for GDB can be installed. The location
2919 of that directory is <data-directory>/python, where <data-directory>
2920 is the GDB data directory. For more details, see section `Scripting
2921 GDB using Python' in the manual.
2923 ** The GDB Python API now has access to breakpoints, symbols, symbol
2924 tables, program spaces, inferiors, threads and frame's code blocks.
2925 Additionally, GDB Parameters can now be created from the API, and
2926 manipulated via set/show in the CLI.
2928 ** New functions gdb.target_charset, gdb.target_wide_charset,
2929 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2931 ** New exception gdb.GdbError.
2933 ** Pretty-printers are now also looked up in the current program space.
2935 ** Pretty-printers can now be individually enabled and disabled.
2937 ** GDB now looks for names of Python scripts to auto-load in a
2938 special section named `.debug_gdb_scripts', in addition to looking
2939 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2941 * Tracepoint actions were unified with breakpoint commands. In particular,
2942 there are no longer differences in "info break" output for breakpoints and
2943 tracepoints and the "commands" command can be used for both tracepoints and
2944 regular breakpoints.
2948 ARM Symbian arm*-*-symbianelf*
2950 * D language support.
2951 GDB now supports debugging programs written in the D programming
2954 * GDB now supports the extended ptrace interface for PowerPC which is
2955 available since Linux kernel version 2.6.34. This automatically enables
2956 any hardware breakpoints and additional hardware watchpoints available in
2957 the processor. The old ptrace interface exposes just one hardware
2958 watchpoint and no hardware breakpoints.
2960 * GDB is now able to use the Data Value Compare (DVC) register available on
2961 embedded PowerPC processors to implement in hardware simple watchpoint
2962 conditions of the form:
2964 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2966 This works in native GDB running on Linux kernels with the extended ptrace
2967 interface mentioned above.
2969 *** Changes in GDB 7.1
2973 ** Namespace Support
2975 GDB now supports importing of namespaces in C++. This enables the
2976 user to inspect variables from imported namespaces. Support for
2977 namepace aliasing has also been added. So, if a namespace is
2978 aliased in the current scope (e.g. namepace C=A; ) the user can
2979 print variables using the alias (e.g. (gdb) print C::x).
2983 All known bugs relating to the printing of virtual base class were
2984 fixed. It is now possible to call overloaded static methods using a
2989 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2990 and reinterpret_cast<> are now handled by the C++ expression parser.
2994 Xilinx MicroBlaze microblaze-*-*
2999 Xilinx MicroBlaze microblaze
3002 * Multi-program debugging.
3004 GDB now has support for multi-program (a.k.a. multi-executable or
3005 multi-exec) debugging. This allows for debugging multiple inferiors
3006 simultaneously each running a different program under the same GDB
3007 session. See "Debugging Multiple Inferiors and Programs" in the
3008 manual for more information. This implied some user visible changes
3009 in the multi-inferior support. For example, "info inferiors" now
3010 lists inferiors that are not running yet or that have exited
3011 already. See also "New commands" and "New options" below.
3013 * New tracing features
3015 GDB's tracepoint facility now includes several new features:
3017 ** Trace state variables
3019 GDB tracepoints now include support for trace state variables, which
3020 are variables managed by the target agent during a tracing
3021 experiment. They are useful for tracepoints that trigger each
3022 other, so for instance one tracepoint can count hits in a variable,
3023 and then a second tracepoint has a condition that is true when the
3024 count reaches a particular value. Trace state variables share the
3025 $-syntax of GDB convenience variables, and can appear in both
3026 tracepoint actions and condition expressions. Use the "tvariable"
3027 command to create, and "info tvariables" to view; see "Trace State
3028 Variables" in the manual for more detail.
3032 GDB now includes an option for defining fast tracepoints, which
3033 targets may implement more efficiently, such as by installing a jump
3034 into the target agent rather than a trap instruction. The resulting
3035 speedup can be by two orders of magnitude or more, although the
3036 tradeoff is that some program locations on some target architectures
3037 might not allow fast tracepoint installation, for instance if the
3038 instruction to be replaced is shorter than the jump. To request a
3039 fast tracepoint, use the "ftrace" command, with syntax identical to
3040 the regular trace command.
3042 ** Disconnected tracing
3044 It is now possible to detach GDB from the target while it is running
3045 a trace experiment, then reconnect later to see how the experiment
3046 is going. In addition, a new variable disconnected-tracing lets you
3047 tell the target agent whether to continue running a trace if the
3048 connection is lost unexpectedly.
3052 GDB now has the ability to save the trace buffer into a file, and
3053 then use that file as a target, similarly to you can do with
3054 corefiles. You can select trace frames, print data that was
3055 collected in them, and use tstatus to display the state of the
3056 tracing run at the moment that it was saved. To create a trace
3057 file, use "tsave <filename>", and to use it, do "target tfile
3060 ** Circular trace buffer
3062 You can ask the target agent to handle the trace buffer as a
3063 circular buffer, discarding the oldest trace frames to make room for
3064 newer ones, by setting circular-trace-buffer to on. This feature may
3065 not be available for all target agents.
3070 The disassemble command, when invoked with two arguments, now requires
3071 the arguments to be comma-separated.
3074 The info variables command now displays variable definitions. Files
3075 which only declare a variable are not shown.
3078 The source command is now capable of sourcing Python scripts.
3079 This feature is dependent on the debugger being build with Python
3082 Related to this enhancement is also the introduction of a new command
3083 "set script-extension" (see below).
3085 * New commands (for set/show, see "New options" below)
3087 record save [<FILENAME>]
3088 Save a file (in core file format) containing the process record
3089 execution log for replay debugging at a later time.
3091 record restore <FILENAME>
3092 Restore the process record execution log that was saved at an
3093 earlier time, for replay debugging.
3095 add-inferior [-copies <N>] [-exec <FILENAME>]
3098 clone-inferior [-copies <N>] [ID]
3099 Make a new inferior ready to execute the same program another
3100 inferior has loaded.
3105 maint info program-spaces
3106 List the program spaces loaded into GDB.
3108 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3109 show remote interrupt-sequence
3110 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3111 as the sequence to the remote target in order to interrupt the execution.
3112 Ctrl-C is a default. Some system prefers BREAK which is high level of
3113 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3114 Magic SysRq g. It is BREAK signal and character 'g'.
3116 set remote interrupt-on-connect [on | off]
3117 show remote interrupt-on-connect
3118 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3119 remote target when gdb connects to it. This is needed when you debug
3122 set remotebreak [on | off]
3124 Deprecated. Use "set/show remote interrupt-sequence" instead.
3126 tvariable $NAME [ = EXP ]
3127 Create or modify a trace state variable.
3130 List trace state variables and their values.
3132 delete tvariable $NAME ...
3133 Delete one or more trace state variables.
3136 Evaluate the given expressions without collecting anything into the
3137 trace buffer. (Valid in tracepoint actions only.)
3139 ftrace FN / FILE:LINE / *ADDR
3140 Define a fast tracepoint at the given function, line, or address.
3142 * New expression syntax
3144 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3145 GDB now parses 0b101010 identically with 42.
3149 set follow-exec-mode new|same
3150 show follow-exec-mode
3151 Control whether GDB reuses the same inferior across an exec call or
3152 creates a new one. This is useful to be able to restart the old
3153 executable after the inferior having done an exec call.
3155 set default-collect EXPR, ...
3156 show default-collect
3157 Define a list of expressions to be collected at each tracepoint.
3158 This is a useful way to ensure essential items are not overlooked,
3159 such as registers or a critical global variable.
3161 set disconnected-tracing
3162 show disconnected-tracing
3163 If set to 1, the target is instructed to continue tracing if it
3164 loses its connection to GDB. If 0, the target is to stop tracing
3167 set circular-trace-buffer
3168 show circular-trace-buffer
3169 If set to on, the target is instructed to use a circular trace buffer
3170 and discard the oldest trace frames instead of stopping the trace due
3171 to a full trace buffer. If set to off, the trace stops when the buffer
3172 fills up. Some targets may not support this.
3174 set script-extension off|soft|strict
3175 show script-extension
3176 If set to "off", the debugger does not perform any script language
3177 recognition, and all sourced files are assumed to be GDB scripts.
3178 If set to "soft" (the default), files are sourced according to
3179 filename extension, falling back to GDB scripts if the first
3181 If set to "strict", files are sourced according to filename extension.
3183 set ada trust-PAD-over-XVS on|off
3184 show ada trust-PAD-over-XVS
3185 If off, activate a workaround against a bug in the debugging information
3186 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3187 the GCC sources for more information about the GNAT encoding and
3188 PAD types in particular). It is always safe to set this option to
3189 off, but this introduces a slight performance penalty. The default
3192 * Python API Improvements
3194 ** GDB provides the new class gdb.LazyString. This is useful in
3195 some pretty-printing cases. The new method gdb.Value.lazy_string
3196 provides a simple way to create objects of this type.
3198 ** The fields returned by gdb.Type.fields now have an
3199 `is_base_class' attribute.
3201 ** The new method gdb.Type.range returns the range of an array type.
3203 ** The new method gdb.parse_and_eval can be used to parse and
3204 evaluate an expression.
3206 * New remote packets
3209 Define a trace state variable.
3212 Get the current value of a trace state variable.
3215 Set desired tracing behavior upon disconnection.
3218 Set the trace buffer to be linear or circular.
3221 Get data about the tracepoints currently in use.
3225 Process record now works correctly with hardware watchpoints.
3227 Multiple bug fixes have been made to the mips-irix port, making it
3228 much more reliable. In particular:
3229 - Debugging threaded applications is now possible again. Previously,
3230 GDB would hang while starting the program, or while waiting for
3231 the program to stop at a breakpoint.
3232 - Attaching to a running process no longer hangs.
3233 - An error occurring while loading a core file has been fixed.
3234 - Changing the value of the PC register now works again. This fixes
3235 problems observed when using the "jump" command, or when calling
3236 a function from GDB, or even when assigning a new value to $pc.
3237 - With the "finish" and "return" commands, the return value for functions
3238 returning a small array is now correctly printed.
3239 - It is now possible to break on shared library code which gets executed
3240 during a shared library init phase (code executed while executing
3241 their .init section). Previously, the breakpoint would have no effect.
3242 - GDB is now able to backtrace through the signal handler for
3243 non-threaded programs.
3245 PIE (Position Independent Executable) programs debugging is now supported.
3246 This includes debugging execution of PIC (Position Independent Code) shared
3247 libraries although for that, it should be possible to run such libraries as an
3250 *** Changes in GDB 7.0
3252 * GDB now has an interface for JIT compilation. Applications that
3253 dynamically generate code can create symbol files in memory and register
3254 them with GDB. For users, the feature should work transparently, and
3255 for JIT developers, the interface is documented in the GDB manual in the
3256 "JIT Compilation Interface" chapter.
3258 * Tracepoints may now be conditional. The syntax is as for
3259 breakpoints; either an "if" clause appended to the "trace" command,
3260 or the "condition" command is available. GDB sends the condition to
3261 the target for evaluation using the same bytecode format as is used
3262 for tracepoint actions.
3264 * The disassemble command now supports: an optional /r modifier, print the
3265 raw instructions in hex as well as in symbolic form, and an optional /m
3266 modifier to print mixed source+assembly.
3268 * Process record and replay
3270 In a architecture environment that supports ``process record and
3271 replay'', ``process record and replay'' target can record a log of
3272 the process execution, and replay it with both forward and reverse
3275 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3276 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3277 set execution-direction {forward|reverse}, for targets that support
3280 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3281 feature is available with a native GDB running on kernel version
3284 * GDB now has support for multi-byte and wide character sets on the
3285 target. Strings whose character type is wchar_t, char16_t, or
3286 char32_t are now correctly printed. GDB supports wide- and unicode-
3287 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3288 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3289 `printf'. This feature requires iconv to work properly; if your
3290 system does not have a working iconv, GDB can use GNU libiconv. See
3291 the installation instructions for more information.
3293 * GDB now supports automatic retrieval of shared library files from
3294 remote targets. To use this feature, specify a system root that begins
3295 with the `remote:' prefix, either via the `set sysroot' command or via
3296 the `--with-sysroot' configure-time option.
3298 * "info sharedlibrary" now takes an optional regex of libraries to show,
3299 and it now reports if a shared library has no debugging information.
3301 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3302 now complete on file names.
3304 * When completing in expressions, gdb will attempt to limit
3305 completions to allowable structure or union fields, where appropriate.
3306 For instance, consider:
3308 # struct example { int f1; double f2; };
3309 # struct example variable;
3312 If the user types TAB at the end of this command line, the available
3313 completions will be "f1" and "f2".
3315 * Inlined functions are now supported. They show up in backtraces, and
3316 the "step", "next", and "finish" commands handle them automatically.
3318 * GDB now supports the token-splicing (##) and stringification (#)
3319 operators when expanding macros. It also supports variable-arity
3322 * GDB now supports inspecting extra signal information, exported by
3323 the new $_siginfo convenience variable. The feature is currently
3324 implemented on linux ARM, i386 and amd64.
3326 * GDB can now display the VFP floating point registers and NEON vector
3327 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3328 can provide these registers (requires Linux 2.6.30 or later). Remote
3329 and simulator targets may also provide them.
3331 * New remote packets
3334 Search memory for a sequence of bytes.
3337 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3338 operation over reliable transport links. Use of this packet is
3339 controlled by the `set remote noack-packet' command.
3342 Kill the process with the specified process ID. Use this in preference
3343 to `k' when multiprocess protocol extensions are supported.
3346 Obtains additional operating system information
3350 Read or write additional signal information.
3352 * Removed remote protocol undocumented extension
3354 An undocumented extension to the remote protocol's `S' stop reply
3355 packet that permited the stub to pass a process id was removed.
3356 Remote servers should use the `T' stop reply packet instead.
3358 * GDB now supports multiple function calling conventions according to the
3359 DWARF-2 DW_AT_calling_convention function attribute.
3361 * The SH target utilizes the aforementioned change to distinguish between gcc
3362 and Renesas calling convention. It also adds the new CLI commands
3363 `set/show sh calling-convention'.
3365 * GDB can now read compressed debug sections, as produced by GNU gold
3366 with the --compress-debug-sections=zlib flag.
3368 * 64-bit core files are now supported on AIX.
3370 * Thread switching is now supported on Tru64.
3372 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3373 which will be allocated using malloc later in program execution.
3375 * The qXfer:libraries:read remote procotol packet now allows passing a
3376 list of section offsets.
3378 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3379 conditions handling signals delivered during attach or thread creation
3380 have also been fixed.
3382 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3383 From the user's standpoint, all unqualified instances of True and False
3384 are treated as the standard definitions, regardless of context.
3386 * GDB now parses C++ symbol and type names more flexibly. For
3389 template<typename T> class C { };
3392 GDB will now correctly handle all of:
3394 ptype C<char const *>
3395 ptype C<char const*>
3396 ptype C<const char *>
3397 ptype C<const char*>
3399 * New features in the GDB remote stub, gdbserver
3401 - The "--wrapper" command-line argument tells gdbserver to use a
3402 wrapper program to launch programs for debugging.
3404 - On PowerPC and S/390 targets, it is now possible to use a single
3405 gdbserver executable to debug both 32-bit and 64-bit programs.
3406 (This requires gdbserver itself to be built as a 64-bit executable.)
3408 - gdbserver uses the new noack protocol mode for TCP connections to
3409 reduce communications latency, if also supported and enabled in GDB.
3411 - Support for the sparc64-linux-gnu target is now included in
3414 - The amd64-linux build of gdbserver now supports debugging both
3415 32-bit and 64-bit programs.
3417 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3418 now support hardware watchpoints, and will use them automatically
3423 GDB now has support for scripting using Python. Whether this is
3424 available is determined at configure time.
3426 New GDB commands can now be written in Python.
3428 * Ada tasking support
3430 Ada tasks can now be inspected in GDB. The following commands have
3434 Print the list of Ada tasks.
3436 Print detailed information about task number N.
3438 Print the task number of the current task.
3440 Switch the context of debugging to task number N.
3442 * Support for user-defined prefixed commands. The "define" command can
3443 add new commands to existing prefixes, e.g. "target".
3445 * Multi-inferior, multi-process debugging.
3447 GDB now has generalized support for multi-inferior debugging. See
3448 "Debugging Multiple Inferiors" in the manual for more information.
3449 Although availability still depends on target support, the command
3450 set is more uniform now. The GNU/Linux specific multi-forks support
3451 has been migrated to this new framework. This implied some user
3452 visible changes; see "New commands" and also "Removed commands"
3455 * Target descriptions can now describe the target OS ABI. See the
3456 "Target Description Format" section in the user manual for more
3459 * Target descriptions can now describe "compatible" architectures
3460 to indicate that the target can execute applications for a different
3461 architecture in addition to those for the main target architecture.
3462 See the "Target Description Format" section in the user manual for
3465 * Multi-architecture debugging.
3467 GDB now includes general supports for debugging applications on
3468 hybrid systems that use more than one single processor architecture
3469 at the same time. Each such hybrid architecture still requires
3470 specific support to be added. The only hybrid architecture supported
3471 in this version of GDB is the Cell Broadband Engine.
3473 * GDB now supports integrated debugging of Cell/B.E. applications that
3474 use both the PPU and SPU architectures. To enable support for hybrid
3475 Cell/B.E. debugging, you need to configure GDB to support both the
3476 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3477 --enable-targets configure option.
3479 * Non-stop mode debugging.
3481 For some targets, GDB now supports an optional mode of operation in
3482 which you can examine stopped threads while other threads continue
3483 to execute freely. This is referred to as non-stop mode, with the
3484 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3485 section in the user manual for more information.
3487 To be able to support remote non-stop debugging, a remote stub needs
3488 to implement the non-stop mode remote protocol extensions, as
3489 described in the "Remote Non-Stop" section of the user manual. The
3490 GDB remote stub, gdbserver, has been adjusted to support these
3491 extensions on linux targets.
3493 * New commands (for set/show, see "New options" below)
3495 catch syscall [NAME(S) | NUMBER(S)]
3496 Catch system calls. Arguments, which should be names of system
3497 calls or their numbers, mean catch only those syscalls. Without
3498 arguments, every syscall will be caught. When the inferior issues
3499 any of the specified syscalls, GDB will stop and announce the system
3500 call, both when it is called and when its call returns. This
3501 feature is currently available with a native GDB running on the
3502 Linux Kernel, under the following architectures: x86, x86_64,
3503 PowerPC and PowerPC64.
3505 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3507 Search memory for a sequence of bytes.
3509 maint set python print-stack
3510 maint show python print-stack
3511 Show a stack trace when an error is encountered in a Python script.
3514 Invoke CODE by passing it to the Python interpreter.
3519 These allow macros to be defined, undefined, and listed
3523 Show operating system information about processes.
3526 List the inferiors currently under GDB's control.
3529 Switch focus to inferior number NUM.
3532 Detach from inferior number NUM.
3535 Kill inferior number NUM.
3539 set spu stop-on-load
3540 show spu stop-on-load
3541 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3543 set spu auto-flush-cache
3544 show spu auto-flush-cache
3545 Control whether to automatically flush the software-managed cache
3546 during Cell/B.E. debugging.
3548 set sh calling-convention
3549 show sh calling-convention
3550 Control the calling convention used when calling SH target functions.
3553 show debug timestamp
3554 Control display of timestamps with GDB debugging output.
3556 set disassemble-next-line
3557 show disassemble-next-line
3558 Control display of disassembled source lines or instructions when
3561 set remote noack-packet
3562 show remote noack-packet
3563 Set/show the use of remote protocol QStartNoAckMode packet. See above
3564 under "New remote packets."
3566 set remote query-attached-packet
3567 show remote query-attached-packet
3568 Control use of remote protocol `qAttached' (query-attached) packet.
3570 set remote read-siginfo-object
3571 show remote read-siginfo-object
3572 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3575 set remote write-siginfo-object
3576 show remote write-siginfo-object
3577 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3580 set remote reverse-continue
3581 show remote reverse-continue
3582 Control use of remote protocol 'bc' (reverse-continue) packet.
3584 set remote reverse-step
3585 show remote reverse-step
3586 Control use of remote protocol 'bs' (reverse-step) packet.
3588 set displaced-stepping
3589 show displaced-stepping
3590 Control displaced stepping mode. Displaced stepping is a way to
3591 single-step over breakpoints without removing them from the debuggee.
3592 Also known as "out-of-line single-stepping".
3595 show debug displaced
3596 Control display of debugging info for displaced stepping.
3598 maint set internal-error
3599 maint show internal-error
3600 Control what GDB does when an internal error is detected.
3602 maint set internal-warning
3603 maint show internal-warning
3604 Control what GDB does when an internal warning is detected.
3609 Use a wrapper program to launch programs for debugging.
3611 set multiple-symbols (all|ask|cancel)
3612 show multiple-symbols
3613 The value of this variable can be changed to adjust the debugger behavior
3614 when an expression or a breakpoint location contains an ambiguous symbol
3615 name (an overloaded function name, for instance).
3617 set breakpoint always-inserted
3618 show breakpoint always-inserted
3619 Keep breakpoints always inserted in the target, as opposed to inserting
3620 them when resuming the target, and removing them when the target stops.
3621 This option can improve debugger performance on slow remote targets.
3623 set arm fallback-mode (arm|thumb|auto)
3624 show arm fallback-mode
3625 set arm force-mode (arm|thumb|auto)
3627 These commands control how ARM GDB determines whether instructions
3628 are ARM or Thumb. The default for both settings is auto, which uses
3629 the current CPSR value for instructions without symbols; previous
3630 versions of GDB behaved as if "set arm fallback-mode arm".
3632 set disable-randomization
3633 show disable-randomization
3634 Standalone programs run with the virtual address space randomization enabled
3635 by default on some platforms. This option keeps the addresses stable across
3636 multiple debugging sessions.
3640 Control whether other threads are stopped or not when some thread hits
3645 Requests that asynchronous execution is enabled in the target, if available.
3646 In this case, it's possible to resume target in the background, and interact
3647 with GDB while the target is running. "show target-async" displays the
3648 current state of asynchronous execution of the target.
3650 set target-wide-charset
3651 show target-wide-charset
3652 The target-wide-charset is the name of the character set that GDB
3653 uses when printing characters whose type is wchar_t.
3655 set tcp auto-retry (on|off)
3657 set tcp connect-timeout
3658 show tcp connect-timeout
3659 These commands allow GDB to retry failed TCP connections to a remote stub
3660 with a specified timeout period; this is useful if the stub is launched
3661 in parallel with GDB but may not be ready to accept connections immediately.
3663 set libthread-db-search-path
3664 show libthread-db-search-path
3665 Control list of directories which GDB will search for appropriate
3668 set schedule-multiple (on|off)
3669 show schedule-multiple
3670 Allow GDB to resume all threads of all processes or only threads of
3671 the current process.
3675 Use more aggressive caching for accesses to the stack. This improves
3676 performance of remote debugging (particularly backtraces) without
3677 affecting correctness.
3679 set interactive-mode (on|off|auto)
3680 show interactive-mode
3681 Control whether GDB runs in interactive mode (on) or not (off).
3682 When in interactive mode, GDB waits for the user to answer all
3683 queries. Otherwise, GDB does not wait and assumes the default
3684 answer. When set to auto (the default), GDB determines which
3685 mode to use based on the stdin settings.
3690 For program forks, this is replaced by the new more generic `info
3691 inferiors' command. To list checkpoints, you can still use the
3692 `info checkpoints' command, which was an alias for the `info forks'
3696 Replaced by the new `inferior' command. To switch between
3697 checkpoints, you can still use the `restart' command, which was an
3698 alias for the `fork' command.
3701 This is removed, since some targets don't have a notion of
3702 processes. To switch between processes, you can still use the
3703 `inferior' command using GDB's own inferior number.
3706 For program forks, this is replaced by the new more generic `kill
3707 inferior' command. To delete a checkpoint, you can still use the
3708 `delete checkpoint' command, which was an alias for the `delete
3712 For program forks, this is replaced by the new more generic `detach
3713 inferior' command. To detach a checkpoint, you can still use the
3714 `detach checkpoint' command, which was an alias for the `detach
3717 * New native configurations
3719 x86/x86_64 Darwin i[34567]86-*-darwin*
3721 x86_64 MinGW x86_64-*-mingw*
3725 Lattice Mico32 lm32-*
3726 x86 DICOS i[34567]86-*-dicos*
3727 x86_64 DICOS x86_64-*-dicos*
3730 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3731 (mingw32ce) debugging.
3737 These commands were actually not implemented on any target.
3739 *** Changes in GDB 6.8
3741 * New native configurations
3743 NetBSD/hppa hppa*-*netbsd*
3744 Xtensa GNU/Linux xtensa*-*-linux*
3748 NetBSD/hppa hppa*-*-netbsd*
3749 Xtensa GNU/Lunux xtensa*-*-linux*
3751 * Change in command line behavior -- corefiles vs. process ids.
3753 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3754 attaching to process NUMBER fails, GDB no longer attempts to open a
3755 core file named NUMBER. Attaching to a program using the -c option
3756 is no longer supported. Instead, use the '-p' or '--pid' options.
3758 * GDB can now be built as a native debugger for debugging Windows x86
3759 (mingw32) Portable Executable (PE) programs.
3761 * Pending breakpoints no longer change their number when their address
3764 * GDB now supports breakpoints with multiple locations,
3765 including breakpoints on C++ constructors, inside C++ templates,
3766 and in inlined functions.
3768 * GDB's ability to debug optimized code has been improved. GDB more
3769 accurately identifies function bodies and lexical blocks that occupy
3770 more than one contiguous range of addresses.
3772 * Target descriptions can now describe registers for PowerPC.
3774 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3775 registers on PowerPC targets.
3777 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3778 targets even when the libthread_db library is not available.
3780 * The GDB remote stub, gdbserver, now supports the new file transfer
3781 commands (remote put, remote get, and remote delete).
3783 * The GDB remote stub, gdbserver, now supports run and attach in
3784 extended-remote mode.
3786 * hppa*64*-*-hpux11* target broken
3787 The debugger is unable to start a program and fails with the following
3788 error: "Error trying to get information about dynamic linker".
3789 The gdb-6.7 release is also affected.
3791 * GDB now supports the --enable-targets= configure option to allow
3792 building a single GDB executable that supports multiple remote
3793 target architectures.
3795 * GDB now supports debugging C and C++ programs which use the
3796 Decimal Floating Point extension. In addition, the PowerPC target
3797 now has a set of pseudo-registers to inspect decimal float values
3798 stored in two consecutive float registers.
3800 * The -break-insert MI command can optionally create pending
3803 * Improved support for debugging Ada
3804 Many improvements to the Ada language support have been made. These
3806 - Better support for Ada2005 interface types
3807 - Improved handling of arrays and slices in general
3808 - Better support for Taft-amendment types
3809 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3811 - Improved command completion in Ada
3814 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3819 set print frame-arguments (all|scalars|none)
3820 show print frame-arguments
3821 The value of this variable can be changed to control which argument
3822 values should be printed by the debugger when displaying a frame.
3827 Transfer files to and from a remote target, and delete remote files.
3834 Transfer files to and from a remote target, and delete remote files.
3836 * New remote packets
3843 Open, close, read, write, and delete files on the remote system.
3846 Attach to an existing process on the remote system, in extended-remote
3850 Run a new process on the remote system, in extended-remote mode.
3852 *** Changes in GDB 6.7
3854 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3855 bfd, libiberty and opcodes, as revealed by static analysis donated by
3856 Coverity, Inc. (http://scan.coverity.com).
3858 * When looking up multiply-defined global symbols, GDB will now prefer the
3859 symbol definition in the current shared library if it was built using the
3860 -Bsymbolic linker option.
3862 * When the Text User Interface (TUI) is not configured, GDB will now
3863 recognize the -tui command-line option and print a message that the TUI
3866 * The GDB remote stub, gdbserver, now has lower overhead for high
3867 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3869 * GDB for MIPS targets now autodetects whether a remote target provides
3870 32-bit or 64-bit register values.
3872 * Support for C++ member pointers has been improved.
3874 * GDB now understands XML target descriptions, which specify the
3875 target's overall architecture. GDB can read a description from
3876 a local file or over the remote serial protocol.
3878 * Vectors of single-byte data use a new integer type which is not
3879 automatically displayed as character or string data.
3881 * The /s format now works with the print command. It displays
3882 arrays of single-byte integers and pointers to single-byte integers
3885 * Target descriptions can now describe target-specific registers,
3886 for architectures which have implemented the support (currently
3887 only ARM, M68K, and MIPS).
3889 * GDB and the GDB remote stub, gdbserver, now support the XScale
3892 * The GDB remote stub, gdbserver, has been updated to support
3893 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3894 has been rewritten to use the standard GDB remote protocol.
3896 * GDB can now step into C++ functions which are called through thunks.
3898 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3900 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3901 layout. It also supports a TextSeg= and DataSeg= response when only
3902 segment base addresses (rather than offsets) are available.
3904 * The /i format now outputs any trailing branch delay slot instructions
3905 immediately following the last instruction within the count specified.
3907 * The GDB remote protocol "T" stop reply packet now supports a
3908 "library" response. Combined with the new "qXfer:libraries:read"
3909 packet, this response allows GDB to debug shared libraries on targets
3910 where the operating system manages the list of loaded libraries (e.g.
3911 Windows and SymbianOS).
3913 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3914 (DLLs) on Windows and Windows CE targets.
3916 * GDB now supports a faster verification that a .debug file matches its binary
3917 according to its build-id signature, if the signature is present.
3923 Enable or disable hardware flow control (RTS/CTS) on the serial port
3924 when debugging using remote targets.
3926 set mem inaccessible-by-default
3927 show mem inaccessible-by-default
3928 If the target supplies a memory map, for instance via the remote
3929 protocol's "qXfer:memory-map:read" packet, setting this variable
3930 prevents GDB from accessing memory outside the memory map. This
3931 is useful for targets with memory mapped registers or which react
3932 badly to accesses of unmapped address space.
3934 set breakpoint auto-hw
3935 show breakpoint auto-hw
3936 If the target supplies a memory map, for instance via the remote
3937 protocol's "qXfer:memory-map:read" packet, setting this variable
3938 lets GDB use hardware breakpoints automatically for memory regions
3939 where it can not use software breakpoints. This covers both the
3940 "break" command and internal breakpoints used for other commands
3941 including "next" and "finish".
3944 catch exception unhandled
3945 Stop the program execution when Ada exceptions are raised.
3948 Stop the program execution when an Ada assertion failed.
3952 Set an alternate system root for target files. This is a more
3953 general version of "set solib-absolute-prefix", which is now
3954 an alias to "set sysroot".
3957 Provide extended SPU facility status information. This set of
3958 commands is available only when debugging the Cell/B.E. SPU
3961 * New native configurations
3963 OpenBSD/sh sh*-*openbsd*
3966 unset tdesc filename
3968 Use the specified local file as an XML target description, and do
3969 not query the target for its built-in description.
3973 OpenBSD/sh sh*-*-openbsd*
3974 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3975 Toshiba Media Processor mep-elf
3977 * New remote packets
3980 Ignore the specified signals; pass them directly to the debugged program
3981 without stopping other threads or reporting them to GDB.
3983 qXfer:features:read:
3984 Read an XML target description from the target, which describes its
3989 Read or write contents of an spufs file on the target system. These
3990 packets are available only on the Cell/B.E. SPU architecture.
3992 qXfer:libraries:read:
3993 Report the loaded shared libraries. Combined with new "T" packet
3994 response, this packet allows GDB to debug shared libraries on
3995 targets where the operating system manages the list of loaded
3996 libraries (e.g. Windows and SymbianOS).
4000 Support for these obsolete configurations has been removed.
4008 i[34567]86-*-lynxos*
4009 i[34567]86-*-netware*
4010 i[34567]86-*-sco3.2v5*
4011 i[34567]86-*-sco3.2v4*
4013 i[34567]86-*-sysv4.2*
4016 i[34567]86-*-unixware2*
4017 i[34567]86-*-unixware*
4026 * Other removed features
4033 Various m68k-only ROM monitors.
4040 Various Renesas ROM monitors and debugging interfaces for SH and
4045 Support for a Macraigor serial interface to on-chip debugging.
4046 GDB does not directly support the newer parallel or USB
4051 A debug information format. The predecessor to DWARF 2 and
4052 DWARF 3, which are still supported.
4054 Support for the HP aCC compiler on HP-UX/PA-RISC
4056 SOM-encapsulated symbolic debugging information, automatic
4057 invocation of pxdb, and the aCC custom C++ ABI. This does not
4058 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4059 with aCC can still be debugged on an assembly level.
4061 MIPS ".pdr" sections
4063 A MIPS-specific format used to describe stack frame layout
4064 in debugging information.
4068 GDB could work with an older version of Guile to debug
4069 the interpreter and Scheme programs running in it.
4071 set mips stack-arg-size
4072 set mips saved-gpreg-size
4074 Use "set mips abi" to control parameter passing for MIPS.
4076 *** Changes in GDB 6.6
4081 Cell Broadband Engine SPU spu-elf
4083 * GDB can now be configured as a cross-debugger targeting native Windows
4084 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4085 running on a Windows system over TCP/IP to debug Windows programs.
4087 * The GDB remote stub, gdbserver, has been updated to support Windows and
4088 Cygwin debugging. Both single-threaded and multi-threaded programs are
4091 * The "set trust-readonly-sections" command works again. This command was
4092 broken in GDB 6.3, 6.4, and 6.5.
4094 * The "load" command now supports writing to flash memory, if the remote
4095 stub provides the required support.
4097 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4098 longer requires symbolic debug information (e.g. DWARF-2).
4103 unset substitute-path
4104 show substitute-path
4105 Manage a list of substitution rules that GDB uses to rewrite the name
4106 of the directories where the sources are located. This can be useful
4107 for instance when the sources were moved to a different location
4108 between compilation and debugging.
4112 Print each CLI command as it is executed. Each command is prefixed with
4113 a number of `+' symbols representing the nesting depth.
4114 The source command now has a `-v' option to enable the same feature.
4118 The ARM Demon monitor support (RDP protocol, "target rdp").
4120 Kernel Object Display, an embedded debugging feature which only worked with
4121 an obsolete version of Cisco IOS.
4123 The 'set download-write-size' and 'show download-write-size' commands.
4125 * New remote packets
4128 Tell a stub about GDB client features, and request remote target features.
4129 The first feature implemented is PacketSize, which allows the target to
4130 specify the size of packets it can handle - to minimize the number of
4131 packets required and improve performance when connected to a remote
4135 Fetch an OS auxilliary vector from the remote stub. This packet is a
4136 more efficient replacement for qPart:auxv:read.
4138 qXfer:memory-map:read:
4139 Fetch a memory map from the remote stub, including information about
4140 RAM, ROM, and flash memory devices.
4145 Erase and program a flash memory device.
4147 * Removed remote packets
4150 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4151 used it, and only gdbserver implemented it.
4153 *** Changes in GDB 6.5
4157 Renesas M32C/M16C m32c-elf
4159 Morpho Technologies ms1 ms1-elf
4163 init-if-undefined Initialize a convenience variable, but
4164 only if it doesn't already have a value.
4166 The following commands are presently only implemented for native GNU/Linux:
4168 checkpoint Save a snapshot of the program state.
4170 restart <n> Return the program state to a
4171 previously saved state.
4173 info checkpoints List currently saved checkpoints.
4175 delete-checkpoint <n> Delete a previously saved checkpoint.
4177 set|show detach-on-fork Tell gdb whether to detach from a newly
4178 forked process, or to keep debugging it.
4180 info forks List forks of the user program that
4181 are available to be debugged.
4183 fork <n> Switch to debugging one of several
4184 forks of the user program that are
4185 available to be debugged.
4187 delete-fork <n> Delete a fork from the list of forks
4188 that are available to be debugged (and
4189 kill the forked process).
4191 detach-fork <n> Delete a fork from the list of forks
4192 that are available to be debugged (and
4193 allow the process to continue).
4197 Morpho Technologies ms2 ms1-elf
4199 * Improved Windows host support
4201 GDB now builds as a cross debugger hosted on i686-mingw32, including
4202 native console support, and remote communications using either
4203 network sockets or serial ports.
4205 * Improved Modula-2 language support
4207 GDB can now print most types in the Modula-2 syntax. This includes:
4208 basic types, set types, record types, enumerated types, range types,
4209 pointer types and ARRAY types. Procedure var parameters are correctly
4210 printed and hexadecimal addresses and character constants are also
4211 written in the Modula-2 syntax. Best results can be obtained by using
4212 GNU Modula-2 together with the -gdwarf-2 command line option.
4216 The ARM rdi-share module.
4218 The Netware NLM debug server.
4220 *** Changes in GDB 6.4
4222 * New native configurations
4224 OpenBSD/arm arm*-*-openbsd*
4225 OpenBSD/mips64 mips64-*-openbsd*
4229 Morpho Technologies ms1 ms1-elf
4231 * New command line options
4233 --batch-silent As for --batch, but totally silent.
4234 --return-child-result The debugger will exist with the same value
4235 the child (debugged) program exited with.
4236 --eval-command COMMAND, -ex COMMAND
4237 Execute a single GDB CLI command. This may be
4238 specified multiple times and in conjunction
4239 with the --command (-x) option.
4241 * Deprecated commands removed
4243 The following commands, that were deprecated in 2000, have been
4247 set|show arm disassembly-flavor set|show arm disassembler
4248 othernames set arm disassembler
4249 set|show remotedebug set|show debug remote
4250 set|show archdebug set|show debug arch
4251 set|show eventdebug set|show debug event
4254 * New BSD user-level threads support
4256 It is now possible to debug programs using the user-level threads
4257 library on OpenBSD and FreeBSD. Currently supported (target)
4260 FreeBSD/amd64 x86_64-*-freebsd*
4261 FreeBSD/i386 i386-*-freebsd*
4262 OpenBSD/i386 i386-*-openbsd*
4264 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4265 are not yet supported.
4267 * New support for Matsushita MN10300 w/sim added
4268 (Work in progress). mn10300-elf.
4270 * REMOVED configurations and files
4272 VxWorks and the XDR protocol *-*-vxworks
4273 Motorola MCORE mcore-*-*
4274 National Semiconductor NS32000 ns32k-*-*
4276 * New "set print array-indexes" command
4278 After turning this setting "on", GDB prints the index of each element
4279 when displaying arrays. The default is "off" to preserve the previous
4282 * VAX floating point support
4284 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4286 * User-defined command support
4288 In addition to using $arg0..$arg9 for argument passing, it is now possible
4289 to use $argc to determine now many arguments have been passed. See the
4290 section on user-defined commands in the user manual for more information.
4292 *** Changes in GDB 6.3:
4294 * New command line option
4296 GDB now accepts -l followed by a number to set the timeout for remote
4299 * GDB works with GCC -feliminate-dwarf2-dups
4301 GDB now supports a more compact representation of DWARF-2 debug
4302 information using DW_FORM_ref_addr references. These are produced
4303 by GCC with the option -feliminate-dwarf2-dups and also by some
4304 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4305 to use -feliminate-dwarf2-dups.
4307 * Internationalization
4309 When supported by the host system, GDB will be built with
4310 internationalization (libintl). The task of marking up the sources is
4311 continued, we're looking forward to our first translation.
4315 Initial support for debugging programs compiled with the GNAT
4316 implementation of the Ada programming language has been integrated
4317 into GDB. In this release, support is limited to expression evaluation.
4319 * New native configurations
4321 GNU/Linux/m32r m32r-*-linux-gnu
4325 GDB's remote protocol now includes support for the 'p' packet. This
4326 packet is used to fetch individual registers from a remote inferior.
4328 * END-OF-LIFE registers[] compatibility module
4330 GDB's internal register infrastructure has been completely rewritten.
4331 The new infrastructure making possible the implementation of key new
4332 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4335 GDB 6.3 will be the last release to include the the registers[]
4336 compatibility module that allowed out-of-date configurations to
4337 continue to work. This change directly impacts the following
4347 powerpc bdm protocol
4349 Unless there is activity to revive these configurations, they will be
4350 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4352 * OBSOLETE configurations and files
4354 Configurations that have been declared obsolete in this release have
4355 been commented out. Unless there is activity to revive these
4356 configurations, the next release of GDB will have their sources
4357 permanently REMOVED.
4366 *** Changes in GDB 6.2.1:
4368 * MIPS `break main; run' gave an heuristic-fence-post warning
4370 When attempting to run even a simple program, a warning about
4371 heuristic-fence-post being hit would be reported. This problem has
4374 * MIPS IRIX 'long double' crashed GDB
4376 When examining a long double variable, GDB would get a segmentation
4377 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4378 IRIX long double values).
4382 A bug in the VAX stack code was causing problems with the "next"
4383 command. This problem has been fixed.
4385 *** Changes in GDB 6.2:
4387 * Fix for ``many threads''
4389 On GNU/Linux systems that use the NPTL threads library, a program
4390 rapidly creating and deleting threads would confuse GDB leading to the
4393 ptrace: No such process.
4394 thread_db_get_info: cannot get thread info: generic error
4396 This problem has been fixed.
4398 * "-async" and "-noasync" options removed.
4400 Support for the broken "-noasync" option has been removed (it caused
4403 * New ``start'' command.
4405 This command runs the program until the begining of the main procedure.
4407 * New BSD Kernel Data Access Library (libkvm) interface
4409 Using ``target kvm'' it is now possible to debug kernel core dumps and
4410 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4411 platforms. Currently supported (native-only) configurations are:
4413 FreeBSD/amd64 x86_64-*-freebsd*
4414 FreeBSD/i386 i?86-*-freebsd*
4415 NetBSD/i386 i?86-*-netbsd*
4416 NetBSD/m68k m68*-*-netbsd*
4417 NetBSD/sparc sparc-*-netbsd*
4418 OpenBSD/amd64 x86_64-*-openbsd*
4419 OpenBSD/i386 i?86-*-openbsd*
4420 OpenBSD/m68k m68*-openbsd*
4421 OpenBSD/sparc sparc-*-openbsd*
4423 * Signal trampoline code overhauled
4425 Many generic problems with GDB's signal handling code have been fixed.
4426 These include: backtraces through non-contiguous stacks; recognition
4427 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4428 call; backtrace through a signal trampoline; step into and out of
4429 signal handlers; and single-stepping in the signal trampoline.
4431 Please note that kernel bugs are a limiting factor here. These
4432 features have been shown to work on an s390 GNU/Linux system that
4433 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4435 * Cygwin support for DWARF 2 added.
4437 * New native configurations
4439 GNU/Linux/hppa hppa*-*-linux*
4440 OpenBSD/hppa hppa*-*-openbsd*
4441 OpenBSD/m68k m68*-*-openbsd*
4442 OpenBSD/m88k m88*-*-openbsd*
4443 OpenBSD/powerpc powerpc-*-openbsd*
4444 NetBSD/vax vax-*-netbsd*
4445 OpenBSD/vax vax-*-openbsd*
4447 * END-OF-LIFE frame compatibility module
4449 GDB's internal frame infrastructure has been completely rewritten.
4450 The new infrastructure making it possible to support key new features
4451 including DWARF 2 Call Frame Information. To aid in the task of
4452 migrating old configurations to this new infrastructure, a
4453 compatibility module, that allowed old configurations to continue to
4454 work, was also included.
4456 GDB 6.2 will be the last release to include this frame compatibility
4457 module. This change directly impacts the following configurations:
4467 Unless there is activity to revive these configurations, they will be
4468 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4470 * REMOVED configurations and files
4472 Sun 3, running SunOS 3 m68*-*-sunos3*
4473 Sun 3, running SunOS 4 m68*-*-sunos4*
4474 Sun 2, running SunOS 3 m68000-*-sunos3*
4475 Sun 2, running SunOS 4 m68000-*-sunos4*
4476 Motorola 680x0 running LynxOS m68*-*-lynxos*
4477 AT&T 3b1/Unix pc m68*-att-*
4478 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4479 decstation mips-dec-* mips-little-*
4480 riscos mips-*-riscos* mips-*-sysv*
4481 sonymips mips-sony-*
4482 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4484 *** Changes in GDB 6.1.1:
4486 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4488 The TUI (Text-mode User Interface) is now built as part of a default
4489 GDB configuration. It is enabled by either selecting the TUI with the
4490 command line option "-i=tui" or by running the separate "gdbtui"
4491 program. For more information on the TUI, see the manual "Debugging
4494 * Pending breakpoint support (also included in GDB 6.1)
4496 Support has been added to allow you to specify breakpoints in shared
4497 libraries that have not yet been loaded. If a breakpoint location
4498 cannot be found, and the "breakpoint pending" option is set to auto,
4499 GDB queries you if you wish to make the breakpoint pending on a future
4500 shared-library load. If and when GDB resolves the breakpoint symbol,
4501 the pending breakpoint is removed as one or more regular breakpoints
4504 Pending breakpoints are very useful for GCJ Java debugging.
4506 * Fixed ISO-C build problems
4508 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4509 non ISO-C code that stopped them being built using a more strict ISO-C
4510 compiler (e.g., IBM's C compiler).
4512 * Fixed build problem on IRIX 5
4514 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4515 wasn't able to compile compile on an IRIX 5 system.
4517 * Added execute permission to gdb/gdbserver/configure
4519 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4520 permission. This bug would cause configure to fail on a number of
4521 systems (Solaris, IRIX). Ref: server/519.
4523 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4525 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4526 has been updated to use constant array sizes.
4528 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4530 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4531 its generated DWARF Call Frame Info. This encoding was causing GDB to
4532 panic, that panic has been fixed. Ref: gdb/1628.
4534 * Fixed a problem when examining parameters in shared library code.
4536 When examining parameters in optimized shared library code generated
4537 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4538 not available''. GDB now correctly displays the variable's value.
4540 *** Changes in GDB 6.1:
4542 * Removed --with-mmalloc
4544 Support for the mmalloc memory manager has been removed, as it
4545 conflicted with the internal gdb byte cache.
4547 * Changes in AMD64 configurations
4549 The AMD64 target now includes the %cs and %ss registers. As a result
4550 the AMD64 remote protocol has changed; this affects the floating-point
4551 and SSE registers. If you rely on those registers for your debugging,
4552 you should upgrade gdbserver on the remote side.
4554 * Revised SPARC target
4556 The SPARC target has been completely revised, incorporating the
4557 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4558 support for LynxOS and SunOS 4 has been dropped. Calling functions
4559 from within GDB on operating systems with a non-executable stack
4560 (Solaris, OpenBSD) now works.
4564 GDB has a new C++ demangler which does a better job on the mangled
4565 names generated by current versions of g++. It also runs faster, so
4566 with this and other changes gdb should now start faster on large C++
4569 * DWARF 2 Location Expressions
4571 GDB support for location expressions has been extended to support function
4572 arguments and frame bases. Older versions of GDB could crash when they
4575 * C++ nested types and namespaces
4577 GDB's support for nested types and namespaces in C++ has been
4578 improved, especially if you use the DWARF 2 debugging format. (This
4579 is the default for recent versions of GCC on most platforms.)
4580 Specifically, if you have a class "Inner" defined within a class or
4581 namespace "Outer", then GDB realizes that the class's name is
4582 "Outer::Inner", not simply "Inner". This should greatly reduce the
4583 frequency of complaints about not finding RTTI symbols. In addition,
4584 if you are stopped at inside of a function defined within a namespace,
4585 GDB modifies its name lookup accordingly.
4587 * New native configurations
4589 NetBSD/amd64 x86_64-*-netbsd*
4590 OpenBSD/amd64 x86_64-*-openbsd*
4591 OpenBSD/alpha alpha*-*-openbsd*
4592 OpenBSD/sparc sparc-*-openbsd*
4593 OpenBSD/sparc64 sparc64-*-openbsd*
4595 * New debugging protocols
4597 M32R with SDI protocol m32r-*-elf*
4599 * "set prompt-escape-char" command deleted.
4601 The command "set prompt-escape-char" has been deleted. This command,
4602 and its very obscure effet on GDB's prompt, was never documented,
4603 tested, nor mentioned in the NEWS file.
4605 * OBSOLETE configurations and files
4607 Configurations that have been declared obsolete in this release have
4608 been commented out. Unless there is activity to revive these
4609 configurations, the next release of GDB will have their sources
4610 permanently REMOVED.
4612 Sun 3, running SunOS 3 m68*-*-sunos3*
4613 Sun 3, running SunOS 4 m68*-*-sunos4*
4614 Sun 2, running SunOS 3 m68000-*-sunos3*
4615 Sun 2, running SunOS 4 m68000-*-sunos4*
4616 Motorola 680x0 running LynxOS m68*-*-lynxos*
4617 AT&T 3b1/Unix pc m68*-att-*
4618 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4619 decstation mips-dec-* mips-little-*
4620 riscos mips-*-riscos* mips-*-sysv*
4621 sonymips mips-sony-*
4622 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4624 * REMOVED configurations and files
4626 SGI Irix-4.x mips-sgi-irix4 or iris4
4627 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4628 Z8000 simulator z8k-zilog-none or z8ksim
4629 Matsushita MN10200 w/simulator mn10200-*-*
4630 H8/500 simulator h8500-hitachi-hms or h8500hms
4631 HP/PA running BSD hppa*-*-bsd*
4632 HP/PA running OSF/1 hppa*-*-osf*
4633 HP/PA Pro target hppa*-*-pro*
4634 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4635 386BSD i[3456]86-*-bsd*
4636 Sequent family i[3456]86-sequent-sysv4*
4637 i[3456]86-sequent-sysv*
4638 i[3456]86-sequent-bsd*
4639 SPARC running LynxOS sparc-*-lynxos*
4640 SPARC running SunOS 4 sparc-*-sunos4*
4641 Tsqware Sparclet sparclet-*-*
4642 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4644 *** Changes in GDB 6.0:
4648 Support for debugging the Objective-C programming language has been
4649 integrated into GDB.
4651 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4653 DWARF 2's Call Frame Information makes available compiler generated
4654 information that more exactly describes the program's run-time stack.
4655 By using this information, GDB is able to provide more robust stack
4658 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4659 have been updated to use a new backtrace mechanism which includes
4660 DWARF 2 CFI support.
4664 GDB's remote protocol has been extended to include support for hosted
4665 file I/O (where the remote target uses GDB's file system). See GDB's
4666 remote protocol documentation for details.
4668 * All targets using the new architecture framework.
4670 All of GDB's targets have been updated to use the new internal
4671 architecture framework. The way is now open for future GDB releases
4672 to include cross-architecture native debugging support (i386 on amd64,
4675 * GNU/Linux's Thread Local Storage (TLS)
4677 GDB now includes support for for the GNU/Linux implementation of
4678 per-thread variables.
4680 * GNU/Linux's Native POSIX Thread Library (NPTL)
4682 GDB's thread code has been updated to work with either the new
4683 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4685 * Separate debug info.
4687 GDB, in conjunction with BINUTILS, now supports a mechanism for
4688 automatically loading debug information from a separate file. Instead
4689 of shipping full debug and non-debug versions of system libraries,
4690 system integrators can now instead ship just the stripped libraries
4691 and optional debug files.
4693 * DWARF 2 Location Expressions
4695 DWARF 2 Location Expressions allow the compiler to more completely
4696 describe the location of variables (even in optimized code) to the
4699 GDB now includes preliminary support for location expressions (support
4700 for DW_OP_piece is still missing).
4704 A number of long standing bugs that caused GDB to die while starting a
4705 Java application have been fixed. GDB's Java support is now
4706 considered "useable".
4708 * GNU/Linux support for fork, vfork, and exec.
4710 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4711 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4714 * GDB supports logging output to a file
4716 There are two new commands, "set logging" and "show logging", which can be
4717 used to capture GDB's output to a file.
4719 * The meaning of "detach" has changed for gdbserver
4721 The "detach" command will now resume the application, as documented. To
4722 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4725 * d10v, m68hc11 `regs' command deprecated
4727 The `info registers' command has been updated so that it displays the
4728 registers using a format identical to the old `regs' command.
4732 A new command, "maint set profile on/off", has been added. This command can
4733 be used to enable or disable profiling while running GDB, to profile a
4734 session or a set of commands. In addition there is a new configure switch,
4735 "--enable-profiling", which will cause GDB to be compiled with profiling
4736 data, for more informative profiling results.
4738 * Default MI syntax changed to "mi2".
4740 The default MI (machine interface) syntax, enabled by the command line
4741 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4742 "mi1", can be enabled by specifying the option "-i=mi1".
4744 Support for the original "mi0" syntax (included in GDB 5.0) has been
4747 Fix for gdb/192: removed extraneous space when displaying frame level.
4748 Fix for gdb/672: update changelist is now output in mi list format.
4749 Fix for gdb/702: a -var-assign that updates the value now shows up
4750 in a subsequent -var-update.
4752 * New native configurations.
4754 FreeBSD/amd64 x86_64-*-freebsd*
4756 * Multi-arched targets.
4758 HP/PA HPUX11 hppa*-*-hpux*
4759 Renesas M32R/D w/simulator m32r-*-elf*
4761 * OBSOLETE configurations and files
4763 Configurations that have been declared obsolete in this release have
4764 been commented out. Unless there is activity to revive these
4765 configurations, the next release of GDB will have their sources
4766 permanently REMOVED.
4768 Z8000 simulator z8k-zilog-none or z8ksim
4769 Matsushita MN10200 w/simulator mn10200-*-*
4770 H8/500 simulator h8500-hitachi-hms or h8500hms
4771 HP/PA running BSD hppa*-*-bsd*
4772 HP/PA running OSF/1 hppa*-*-osf*
4773 HP/PA Pro target hppa*-*-pro*
4774 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4775 Sequent family i[3456]86-sequent-sysv4*
4776 i[3456]86-sequent-sysv*
4777 i[3456]86-sequent-bsd*
4778 Tsqware Sparclet sparclet-*-*
4779 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4781 * REMOVED configurations and files
4784 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4785 IBM AIX PS/2 i[3456]86-*-aix
4786 i386 running Mach 3.0 i[3456]86-*-mach3*
4787 i386 running Mach i[3456]86-*-mach*
4788 i386 running OSF/1 i[3456]86-*osf1mk*
4789 HP/Apollo 68k Family m68*-apollo*-sysv*,
4791 m68*-hp-bsd*, m68*-hp-hpux*
4792 Argonaut Risc Chip (ARC) arc-*-*
4793 Mitsubishi D30V d30v-*-*
4794 Fujitsu FR30 fr30-*-elf*
4795 OS/9000 i[34]86-*-os9k
4796 I960 with MON960 i960-*-coff
4798 * MIPS $fp behavior changed
4800 The convenience variable $fp, for the MIPS, now consistently returns
4801 the address of the current frame's base. Previously, depending on the
4802 context, $fp could refer to either $sp or the current frame's base
4803 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4804 The GNU Source-Level Debugger''.
4806 *** Changes in GDB 5.3:
4808 * GNU/Linux shared library multi-threaded performance improved.
4810 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4811 `/proc', in preference to `ptrace' for memory reads. This may result
4812 in an improvement in the start-up time of multi-threaded, shared
4813 library applications when run under GDB. One GDB user writes: ``loads
4814 shared libs like mad''.
4816 * ``gdbserver'' now supports multi-threaded applications on some targets
4818 Support for debugging multi-threaded applications which use
4819 the GNU/Linux LinuxThreads package has been added for
4820 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4821 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4823 * GDB now supports C/C++ preprocessor macros.
4825 GDB now expands preprocessor macro invocations in C/C++ expressions,
4826 and provides various commands for showing macro definitions and how
4829 The new command `macro expand EXPRESSION' expands any macro
4830 invocations in expression, and shows the result.
4832 The new command `show macro MACRO-NAME' shows the definition of the
4833 macro named MACRO-NAME, and where it was defined.
4835 Most compilers don't include information about macros in the debugging
4836 information by default. In GCC 3.1, for example, you need to compile
4837 your program with the options `-gdwarf-2 -g3'. If the macro
4838 information is present in the executable, GDB will read it.
4840 * Multi-arched targets.
4842 DEC Alpha (partial) alpha*-*-*
4843 DEC VAX (partial) vax-*-*
4845 National Semiconductor NS32000 (partial) ns32k-*-*
4846 Motorola 68000 (partial) m68k-*-*
4847 Motorola MCORE mcore-*-*
4851 Fujitsu FRV architecture added by Red Hat frv*-*-*
4854 * New native configurations
4856 Alpha NetBSD alpha*-*-netbsd*
4857 SH NetBSD sh*-*-netbsdelf*
4858 MIPS NetBSD mips*-*-netbsd*
4859 UltraSPARC NetBSD sparc64-*-netbsd*
4861 * OBSOLETE configurations and files
4863 Configurations that have been declared obsolete in this release have
4864 been commented out. Unless there is activity to revive these
4865 configurations, the next release of GDB will have their sources
4866 permanently REMOVED.
4868 Mitsubishi D30V d30v-*-*
4869 OS/9000 i[34]86-*-os9k
4870 IBM AIX PS/2 i[3456]86-*-aix
4871 Fujitsu FR30 fr30-*-elf*
4872 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4873 Argonaut Risc Chip (ARC) arc-*-*
4874 i386 running Mach 3.0 i[3456]86-*-mach3*
4875 i386 running Mach i[3456]86-*-mach*
4876 i386 running OSF/1 i[3456]86-*osf1mk*
4877 HP/Apollo 68k Family m68*-apollo*-sysv*,
4879 m68*-hp-bsd*, m68*-hp-hpux*
4880 I960 with MON960 i960-*-coff
4882 * OBSOLETE languages
4884 CHILL, a Pascal like language used by telecommunications companies.
4886 * REMOVED configurations and files
4888 AMD 29k family via UDI a29k-amd-udi, udi29k
4889 A29K VxWorks a29k-*-vxworks
4890 AMD 29000 embedded, using EBMON a29k-none-none
4891 AMD 29000 embedded with COFF a29k-none-coff
4892 AMD 29000 embedded with a.out a29k-none-aout
4894 testsuite/gdb.hp/gdb.threads-hp/ directory
4896 * New command "set max-user-call-depth <nnn>"
4898 This command allows the user to limit the call depth of user-defined
4899 commands. The default is 1024.
4901 * Changes in FreeBSD/i386 native debugging.
4903 Support for the "generate-core-file" has been added.
4905 * New commands "dump", "append", and "restore".
4907 These commands allow data to be copied from target memory
4908 to a bfd-format or binary file (dump and append), and back
4909 from a file into memory (restore).
4911 * Improved "next/step" support on multi-processor Alpha Tru64.
4913 The previous single-step mechanism could cause unpredictable problems,
4914 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4915 of a software single-step mechanism prevents this.
4917 *** Changes in GDB 5.2.1:
4925 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4926 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4927 Fix, by Joel Brobecker imported from mainline.
4929 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4930 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4931 Fix, by Fred Fish, imported from mainline.
4933 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4934 Surprisingly enough, it works now.
4935 By Michal Ludvig, imported from mainline.
4937 i386 hardware watchpoint support:
4938 avoid misses on second run for some targets.
4939 By Pierre Muller, imported from mainline.
4941 *** Changes in GDB 5.2:
4943 * New command "set trust-readonly-sections on[off]".
4945 This command is a hint that tells gdb that read-only sections
4946 really are read-only (ie. that their contents will not change).
4947 In this mode, gdb will go to the object file rather than the
4948 target to read memory from read-only sections (such as ".text").
4949 This can be a significant performance improvement on some
4950 (notably embedded) targets.
4952 * New command "generate-core-file" (or "gcore").
4954 This new gdb command allows the user to drop a core file of the child
4955 process state at any time. So far it's been implemented only for
4956 GNU/Linux and Solaris, but should be relatively easily ported to other
4957 hosts. Argument is core file name (defaults to core.<pid>).
4959 * New command line option
4961 GDB now accepts --pid or -p followed by a process id.
4963 * Change in command line behavior -- corefiles vs. process ids.
4965 There is a subtle behavior in the way in which GDB handles
4966 command line arguments. The first non-flag argument is always
4967 a program to debug, but the second non-flag argument may either
4968 be a corefile or a process id. Previously, GDB would attempt to
4969 open the second argument as a corefile, and if that failed, would
4970 issue a superfluous error message and then attempt to attach it as
4971 a process. Now, if the second argument begins with a non-digit,
4972 it will be treated as a corefile. If it begins with a digit,
4973 GDB will attempt to attach it as a process, and if no such process
4974 is found, will then attempt to open it as a corefile.
4976 * Changes in ARM configurations.
4978 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4979 configuration is fully multi-arch.
4981 * New native configurations
4983 ARM NetBSD arm*-*-netbsd*
4984 x86 OpenBSD i[3456]86-*-openbsd*
4985 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4986 Sparc64 running FreeBSD sparc64-*-freebsd*
4990 Sanyo XStormy16 xstormy16-elf
4992 * OBSOLETE configurations and files
4994 Configurations that have been declared obsolete in this release have
4995 been commented out. Unless there is activity to revive these
4996 configurations, the next release of GDB will have their sources
4997 permanently REMOVED.
4999 AMD 29k family via UDI a29k-amd-udi, udi29k
5000 A29K VxWorks a29k-*-vxworks
5001 AMD 29000 embedded, using EBMON a29k-none-none
5002 AMD 29000 embedded with COFF a29k-none-coff
5003 AMD 29000 embedded with a.out a29k-none-aout
5005 testsuite/gdb.hp/gdb.threads-hp/ directory
5007 * REMOVED configurations and files
5009 TI TMS320C80 tic80-*-*
5011 PowerPC Solaris powerpcle-*-solaris*
5012 PowerPC Windows NT powerpcle-*-cygwin32
5013 PowerPC Netware powerpc-*-netware*
5014 Harris/CXUX m88k m88*-harris-cxux*
5015 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5016 ns32k-utek-sysv* ns32k-utek-*
5017 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5018 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5019 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5020 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5021 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5023 * Changes to command line processing
5025 The new `--args' feature can be used to specify command-line arguments
5026 for the inferior from gdb's command line.
5028 * Changes to key bindings
5030 There is a new `operate-and-get-next' function bound to `C-o'.
5032 *** Changes in GDB 5.1.1
5034 Fix compile problem on DJGPP.
5036 Fix a problem with floating-point registers on the i386 being
5039 Fix to stop GDB crashing on .debug_str debug info.
5041 Numerous documentation fixes.
5043 Numerous testsuite fixes.
5045 *** Changes in GDB 5.1:
5047 * New native configurations
5049 Alpha FreeBSD alpha*-*-freebsd*
5050 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5051 MIPS GNU/Linux mips*-*-linux*
5052 MIPS SGI Irix 6.x mips*-sgi-irix6*
5053 ia64 AIX ia64-*-aix*
5054 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5058 Motorola 68HC11 and 68HC12 m68hc11-elf
5060 UltraSparc running GNU/Linux sparc64-*-linux*
5062 * OBSOLETE configurations and files
5064 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5065 Harris/CXUX m88k m88*-harris-cxux*
5066 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5067 ns32k-utek-sysv* ns32k-utek-*
5068 TI TMS320C80 tic80-*-*
5070 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5071 PowerPC Solaris powerpcle-*-solaris*
5072 PowerPC Windows NT powerpcle-*-cygwin32
5073 PowerPC Netware powerpc-*-netware*
5074 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5075 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5076 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5077 Apple Macintosh (MPW) host N/A
5079 stuff.c (Program to stuff files into a specially prepared space in kdb)
5080 kdb-start.c (Main loop for the standalone kernel debugger)
5082 Configurations that have been declared obsolete in this release have
5083 been commented out. Unless there is activity to revive these
5084 configurations, the next release of GDB will have their sources
5085 permanently REMOVED.
5087 * REMOVED configurations and files
5089 Altos 3068 m68*-altos-*
5090 Convex c1-*-*, c2-*-*
5092 ARM RISCix arm-*-* (as host)
5096 * GDB has been converted to ISO C.
5098 GDB's source code has been converted to ISO C. In particular, the
5099 sources are fully protoized, and rely on standard headers being
5104 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5106 * The MI enabled by default.
5108 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5109 revised and enabled by default. Packages which use GDB as a debugging
5110 engine behind a UI or another front end are encouraged to switch to
5111 using the GDB/MI interface, instead of the old annotations interface
5112 which is now deprecated.
5114 * Support for debugging Pascal programs.
5116 GDB now includes support for debugging Pascal programs. The following
5117 main features are supported:
5119 - Pascal-specific data types such as sets;
5121 - automatic recognition of Pascal sources based on file-name
5124 - Pascal-style display of data types, variables, and functions;
5126 - a Pascal expression parser.
5128 However, some important features are not yet supported.
5130 - Pascal string operations are not supported at all;
5132 - there are some problems with boolean types;
5134 - Pascal type hexadecimal constants are not supported
5135 because they conflict with the internal variables format;
5137 - support for Pascal objects and classes is not full yet;
5139 - unlike Pascal, GDB is case-sensitive for symbol names.
5141 * Changes in completion.
5143 Commands such as `shell', `run' and `set args', which pass arguments
5144 to inferior programs, now complete on file names, similar to what
5145 users expect at the shell prompt.
5147 Commands which accept locations, such as `disassemble', `print',
5148 `breakpoint', `until', etc. now complete on filenames as well as
5149 program symbols. Thus, if you type "break foob TAB", and the source
5150 files linked into the programs include `foobar.c', that file name will
5151 be one of the candidates for completion. However, file names are not
5152 considered for completion after you typed a colon that delimits a file
5153 name from a name of a function in that file, as in "break foo.c:bar".
5155 `set demangle-style' completes on available demangling styles.
5157 * New platform-independent commands:
5159 It is now possible to define a post-hook for a command as well as a
5160 hook that runs before the command. For more details, see the
5161 documentation of `hookpost' in the GDB manual.
5163 * Changes in GNU/Linux native debugging.
5165 Support for debugging multi-threaded programs has been completely
5166 revised for all platforms except m68k and sparc. You can now debug as
5167 many threads as your system allows you to have.
5169 Attach/detach is supported for multi-threaded programs.
5171 Support for SSE registers was added for x86. This doesn't work for
5172 multi-threaded programs though.
5174 * Changes in MIPS configurations.
5176 Multi-arch support is enabled for all MIPS configurations.
5178 GDB can now be built as native debugger on SGI Irix 6.x systems for
5179 debugging n32 executables. (Debugging 64-bit executables is not yet
5182 * Unified support for hardware watchpoints in all x86 configurations.
5184 Most (if not all) native x86 configurations support hardware-assisted
5185 breakpoints and watchpoints in a unified manner. This support
5186 implements debug register sharing between watchpoints, which allows to
5187 put a virtually infinite number of watchpoints on the same address,
5188 and also supports watching regions up to 16 bytes with several debug
5191 The new maintenance command `maintenance show-debug-regs' toggles
5192 debugging print-outs in functions that insert, remove, and test
5193 watchpoints and hardware breakpoints.
5195 * Changes in the DJGPP native configuration.
5197 New command ``info dos sysinfo'' displays assorted information about
5198 the CPU, OS, memory, and DPMI server.
5200 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5201 display information about segment descriptors stored in GDT, LDT, and
5204 New commands ``info dos pde'' and ``info dos pte'' display entries
5205 from Page Directory and Page Tables (for now works with CWSDPMI only).
5206 New command ``info dos address-pte'' displays the Page Table entry for
5207 a given linear address.
5209 GDB can now pass command lines longer than 126 characters to the
5210 program being debugged (requires an update to the libdbg.a library
5211 which is part of the DJGPP development kit).
5213 DWARF2 debug info is now supported.
5215 It is now possible to `step' and `next' through calls to `longjmp'.
5217 * Changes in documentation.
5219 All GDB documentation was converted to GFDL, the GNU Free
5220 Documentation License.
5222 Tracepoints-related commands are now fully documented in the GDB
5225 TUI, the Text-mode User Interface, is now documented in the manual.
5227 Tracepoints-related commands are now fully documented in the GDB
5230 The "GDB Internals" manual now has an index. It also includes
5231 documentation of `ui_out' functions, GDB coding standards, x86
5232 hardware watchpoints, and memory region attributes.
5234 * GDB's version number moved to ``version.in''
5236 The Makefile variable VERSION has been replaced by the file
5237 ``version.in''. People creating GDB distributions should update the
5238 contents of this file.
5242 GUD support is now a standard part of the EMACS distribution.
5244 *** Changes in GDB 5.0:
5246 * Improved support for debugging FP programs on x86 targets
5248 Unified and much-improved support for debugging floating-point
5249 programs on all x86 targets. In particular, ``info float'' now
5250 displays the FP registers in the same format on all x86 targets, with
5251 greater level of detail.
5253 * Improvements and bugfixes in hardware-assisted watchpoints
5255 It is now possible to watch array elements, struct members, and
5256 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5257 on x86 targets no longer erroneously trigger when the address is
5260 * Improvements in the native DJGPP version of GDB
5262 The distribution now includes all the scripts and auxiliary files
5263 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5264 machines ``out of the box''.
5266 The DJGPP version can now debug programs that use signals. It is
5267 possible to catch signals that happened in the debuggee, deliver
5268 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5269 would kill the program being debugged.) Programs that hook hardware
5270 interrupts (keyboard, timer, etc.) can also be debugged.
5272 It is now possible to debug DJGPP programs that redirect their
5273 standard handles or switch them to raw (as opposed to cooked) mode, or
5274 even close them. The command ``run < foo > bar'' works as expected,
5275 and ``info terminal'' reports useful information about the debuggee's
5276 terminal, including raw/cooked mode, redirection, etc.
5278 The DJGPP version now uses termios functions for console I/O, which
5279 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5282 DOS-style file names with drive letters are now fully supported by
5285 It is now possible to debug DJGPP programs that switch their working
5286 directory. It is also possible to rerun the debuggee any number of
5287 times without restarting GDB; thus, you can use the same setup,
5288 breakpoints, etc. for many debugging sessions.
5290 * New native configurations
5292 ARM GNU/Linux arm*-*-linux*
5293 PowerPC GNU/Linux powerpc-*-linux*
5297 Motorola MCore mcore-*-*
5298 x86 VxWorks i[3456]86-*-vxworks*
5299 PowerPC VxWorks powerpc-*-vxworks*
5300 TI TMS320C80 tic80-*-*
5302 * OBSOLETE configurations
5304 Altos 3068 m68*-altos-*
5305 Convex c1-*-*, c2-*-*
5307 ARM RISCix arm-*-* (as host)
5310 Configurations that have been declared obsolete will be commented out,
5311 but the code will be left in place. If there is no activity to revive
5312 these configurations before the next release of GDB, the sources will
5313 be permanently REMOVED.
5315 * Gould support removed
5317 Support for the Gould PowerNode and NP1 has been removed.
5319 * New features for SVR4
5321 On SVR4 native platforms (such as Solaris), if you attach to a process
5322 without first loading a symbol file, GDB will now attempt to locate and
5323 load symbols from the running process's executable file.
5325 * Many C++ enhancements
5327 C++ support has been greatly improved. Overload resolution now works properly
5328 in almost all cases. RTTI support is on the way.
5330 * Remote targets can connect to a sub-program
5332 A popen(3) style serial-device has been added. This device starts a
5333 sub-process (such as a stand-alone simulator) and then communicates
5334 with that. The sub-program to run is specified using the syntax
5335 ``|<program> <args>'' vis:
5337 (gdb) set remotedebug 1
5338 (gdb) target extended-remote |mn10300-elf-sim program-args
5340 * MIPS 64 remote protocol
5342 A long standing bug in the mips64 remote protocol where by GDB
5343 expected certain 32 bit registers (ex SR) to be transfered as 32
5344 instead of 64 bits has been fixed.
5346 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5347 added to provide backward compatibility with older versions of GDB.
5349 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5351 The command ``set remotebinarydownload'' command has been replaced by
5352 ``set remote X-packet''. Other commands in ``set remote'' family
5353 include ``set remote P-packet''.
5355 * Breakpoint commands accept ranges.
5357 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5358 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5359 ``tracepoint passcount'' also accepts a range of tracepoints.
5361 * ``apropos'' command added.
5363 The ``apropos'' command searches through command names and
5364 documentation strings, printing out matches, making it much easier to
5365 try to find a command that does what you are looking for.
5369 A new machine oriented interface (MI) has been added to GDB. This
5370 interface is designed for debug environments running GDB as a separate
5371 process. This is part of the long term libGDB project. See the
5372 "GDB/MI" chapter of the GDB manual for further information. It can be
5373 enabled by configuring with:
5375 .../configure --enable-gdbmi
5377 *** Changes in GDB-4.18:
5379 * New native configurations
5381 HP-UX 10.20 hppa*-*-hpux10.20
5382 HP-UX 11.x hppa*-*-hpux11.0*
5383 M68K GNU/Linux m68*-*-linux*
5387 Fujitsu FR30 fr30-*-elf*
5388 Intel StrongARM strongarm-*-*
5389 Mitsubishi D30V d30v-*-*
5391 * OBSOLETE configurations
5393 Gould PowerNode, NP1 np1-*-*, pn-*-*
5395 Configurations that have been declared obsolete will be commented out,
5396 but the code will be left in place. If there is no activity to revive
5397 these configurations before the next release of GDB, the sources will
5398 be permanently REMOVED.
5402 As a compatibility experiment, GDB's source files buildsym.h and
5403 buildsym.c have been converted to pure standard C, no longer
5404 containing any K&R compatibility code. We believe that all systems in
5405 use today either come with a standard C compiler, or have a GCC port
5406 available. If this is not true, please report the affected
5407 configuration to bug-gdb@gnu.org immediately. See the README file for
5408 information about getting a standard C compiler if you don't have one
5413 GDB now uses readline 2.2.
5415 * set extension-language
5417 You can now control the mapping between filename extensions and source
5418 languages by using the `set extension-language' command. For instance,
5419 you can ask GDB to treat .c files as C++ by saying
5420 set extension-language .c c++
5421 The command `info extensions' lists all of the recognized extensions
5422 and their associated languages.
5424 * Setting processor type for PowerPC and RS/6000
5426 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5427 you can use the `set processor' command to specify what variant of the
5428 PowerPC family you are debugging. The command
5432 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5433 following PowerPC and RS6000 variants:
5435 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5436 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5438 403GC IBM PowerPC 403GC
5439 505 Motorola PowerPC 505
5440 860 Motorola PowerPC 860 or 850
5441 601 Motorola PowerPC 601
5442 602 Motorola PowerPC 602
5443 603 Motorola/IBM PowerPC 603 or 603e
5444 604 Motorola PowerPC 604 or 604e
5445 750 Motorola/IBM PowerPC 750 or 750
5447 At the moment, this command just tells GDB what to name the
5448 special-purpose processor registers. Since almost all the affected
5449 registers are inaccessible to user-level programs, this command is
5450 only useful for remote debugging in its present form.
5454 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5455 more extensive support for HP-UX. Added features include shared
5456 library support, kernel threads and hardware watchpoints for 11.00,
5457 support for HP's ANSI C and C++ compilers, and a compatibility mode
5458 for xdb and dbx commands.
5462 HP's donation includes the new concept of catchpoints, which is a
5463 generalization of the old catch command. On HP-UX, it is now possible
5464 to catch exec, fork, and vfork, as well as library loading.
5466 This means that the existing catch command has changed; its first
5467 argument now specifies the type of catch to be set up. See the
5468 output of "help catch" for a list of catchpoint types.
5470 * Debugging across forks
5472 On HP-UX, you can choose which process to debug when a fork() happens
5477 HP has donated a curses-based terminal user interface (TUI). To get
5478 it, build with --enable-tui. Although this can be enabled for any
5479 configuration, at present it only works for native HP debugging.
5481 * GDB remote protocol additions
5483 A new protocol packet 'X' that writes binary data is now available.
5484 Default behavior is to try 'X', then drop back to 'M' if the stub
5485 fails to respond. The settable variable `remotebinarydownload'
5486 allows explicit control over the use of 'X'.
5488 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5489 full 64-bit address. The command
5491 set remoteaddresssize 32
5493 can be used to revert to the old behaviour. For existing remote stubs
5494 the change should not be noticed, as the additional address information
5497 In order to assist in debugging stubs, you may use the maintenance
5498 command `packet' to send any text string to the stub. For instance,
5500 maint packet heythere
5502 sends the packet "$heythere#<checksum>". Note that it is very easy to
5503 disrupt a debugging session by sending the wrong packet at the wrong
5506 The compare-sections command allows you to compare section data on the
5507 target to what is in the executable file without uploading or
5508 downloading, by comparing CRC checksums.
5510 * Tracing can collect general expressions
5512 You may now collect general expressions at tracepoints. This requires
5513 further additions to the target-side stub; see tracepoint.c and
5514 doc/agentexpr.texi for further details.
5516 * mask-address variable for Mips
5518 For Mips targets, you may control the zeroing of the upper 32 bits of
5519 a 64-bit address by entering `set mask-address on'. This is mainly
5520 of interest to users of embedded R4xxx and R5xxx processors.
5522 * Higher serial baud rates
5524 GDB's serial code now allows you to specify baud rates 57600, 115200,
5525 230400, and 460800 baud. (Note that your host system may not be able
5526 to achieve all of these rates.)
5530 The i960 configuration now includes an initial implementation of a
5531 builtin simulator, contributed by Jim Wilson.
5534 *** Changes in GDB-4.17:
5536 * New native configurations
5538 Alpha GNU/Linux alpha*-*-linux*
5539 Unixware 2.x i[3456]86-unixware2*
5540 Irix 6.x mips*-sgi-irix6*
5541 PowerPC GNU/Linux powerpc-*-linux*
5542 PowerPC Solaris powerpcle-*-solaris*
5543 Sparc GNU/Linux sparc-*-linux*
5544 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5548 Argonaut Risc Chip (ARC) arc-*-*
5549 Hitachi H8/300S h8300*-*-*
5550 Matsushita MN10200 w/simulator mn10200-*-*
5551 Matsushita MN10300 w/simulator mn10300-*-*
5552 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5553 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5554 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5555 Mitsubishi D10V w/simulator d10v-*-*
5556 Mitsubishi M32R/D w/simulator m32r-*-elf*
5557 Tsqware Sparclet sparclet-*-*
5558 NEC V850 w/simulator v850-*-*
5560 * New debugging protocols
5562 ARM with RDI protocol arm*-*-*
5563 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5564 DDB and LSI variants of PMON protocol mips*-*-*
5565 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5566 PowerPC with SDS protocol powerpc{,le}-*-eabi
5567 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5571 All configurations can now understand and use the DWARF 2 debugging
5572 format. The choice is automatic, if the symbol file contains DWARF 2
5577 GDB now includes basic Java language support. This support is
5578 only useful with Java compilers that produce native machine code.
5580 * solib-absolute-prefix and solib-search-path
5582 For SunOS and SVR4 shared libraries, you may now set the prefix for
5583 loading absolute shared library symbol files, and the search path for
5584 locating non-absolute shared library symbol files.
5586 * Live range splitting
5588 GDB can now effectively debug code for which GCC has performed live
5589 range splitting as part of its optimization. See gdb/doc/LRS for
5590 more details on the expected format of the stabs information.
5594 GDB's support for the GNU Hurd, including thread debugging, has been
5595 updated to work with current versions of the Hurd.
5599 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5600 instruction set. ARM GDB automatically detects when Thumb
5601 instructions are in use, and adjusts disassembly and backtracing
5606 GDB's MIPS target configurations now handle the MIP16 16-bit
5611 GDB now includes support for overlays; if an executable has been
5612 linked such that multiple sections are based at the same address, GDB
5613 will decide which section to use for symbolic info. You can choose to
5614 control the decision manually, using overlay commands, or implement
5615 additional target-side support and use "overlay load-target" to bring
5616 in the overlay mapping. Do "help overlay" for more detail.
5620 The command "info symbol <address>" displays information about
5621 the symbol at the specified address.
5625 The standard remote protocol now includes an extension that allows
5626 asynchronous collection and display of trace data. This requires
5627 extensive support in the target-side debugging stub. Tracing mode
5628 includes a new interaction mode in GDB and new commands: see the
5629 file tracepoint.c for more details.
5633 Configurations for embedded MIPS now include a simulator contributed
5634 by Cygnus Solutions. The simulator supports the instruction sets
5635 of most MIPS variants.
5639 Sparc configurations may now include the ERC32 simulator contributed
5640 by the European Space Agency. The simulator is not built into
5641 Sparc targets by default; configure with --enable-sim to include it.
5645 For target configurations that may include multiple variants of a
5646 basic architecture (such as MIPS and SH), you may now set the
5647 architecture explicitly. "set arch" sets, "info arch" lists
5648 the possible architectures.
5650 *** Changes in GDB-4.16:
5652 * New native configurations
5654 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5655 M68K NetBSD m68k-*-netbsd*
5656 PowerPC AIX 4.x powerpc-*-aix*
5657 PowerPC MacOS powerpc-*-macos*
5658 PowerPC Windows NT powerpcle-*-cygwin32
5659 RS/6000 AIX 4.x rs6000-*-aix4*
5663 ARM with RDP protocol arm-*-*
5664 I960 with MON960 i960-*-coff
5665 MIPS VxWorks mips*-*-vxworks*
5666 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5667 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5669 Matra Sparclet sparclet-*-*
5673 The powerpc-eabi configuration now includes the PSIM simulator,
5674 contributed by Andrew Cagney, with assistance from Mike Meissner.
5675 PSIM is a very elaborate model of the PowerPC, including not only
5676 basic instruction set execution, but also details of execution unit
5677 performance and I/O hardware. See sim/ppc/README for more details.
5681 GDB now works with Solaris 2.5.
5683 * Windows 95/NT native
5685 GDB will now work as a native debugger on Windows 95 and Windows NT.
5686 To build it from source, you must use the "gnu-win32" environment,
5687 which uses a DLL to emulate enough of Unix to run the GNU tools.
5688 Further information, binaries, and sources are available at
5689 ftp.cygnus.com, under pub/gnu-win32.
5691 * dont-repeat command
5693 If a user-defined command includes the command `dont-repeat', then the
5694 command will not be repeated if the user just types return. This is
5695 useful if the command is time-consuming to run, so that accidental
5696 extra keystrokes don't run the same command many times.
5698 * Send break instead of ^C
5700 The standard remote protocol now includes an option to send a break
5701 rather than a ^C to the target in order to interrupt it. By default,
5702 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5704 * Remote protocol timeout
5706 The standard remote protocol includes a new variable `remotetimeout'
5707 that allows you to set the number of seconds before GDB gives up trying
5708 to read from the target. The default value is 2.
5710 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5712 By default GDB will automatically keep track of objects as they are
5713 loaded and unloaded by the dynamic linker. By using the command `set
5714 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5715 when shared library events occur, thus allowing you to set breakpoints
5716 in shared libraries which are explicitly loaded by the inferior.
5718 Note this feature does not work on hpux8. On hpux9 you must link
5719 /usr/lib/end.o into your program. This feature should work
5720 automatically on hpux10.
5722 * Irix 5.x hardware watchpoint support
5724 Irix 5 configurations now support the use of hardware watchpoints.
5726 * Mips protocol "SYN garbage limit"
5728 When debugging a Mips target using the `target mips' protocol, you
5729 may set the number of characters that GDB will ignore by setting
5730 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5731 every character. The default value is 1050.
5733 * Recording and replaying remote debug sessions
5735 If you set `remotelogfile' to the name of a file, gdb will write to it
5736 a recording of a remote debug session. This recording may then be
5737 replayed back to gdb using "gdbreplay". See gdbserver/README for
5738 details. This is useful when you have a problem with GDB while doing
5739 remote debugging; you can make a recording of the session and send it
5740 to someone else, who can then recreate the problem.
5742 * Speedups for remote debugging
5744 GDB includes speedups for downloading and stepping MIPS systems using
5745 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5746 and more efficient S-record downloading.
5748 * Memory use reductions and statistics collection
5750 GDB now uses less memory and reports statistics about memory usage.
5751 Try the `maint print statistics' command, for example.
5753 *** Changes in GDB-4.15:
5755 * Psymtabs for XCOFF
5757 The symbol reader for AIX GDB now uses partial symbol tables. This
5758 can greatly improve startup time, especially for large executables.
5760 * Remote targets use caching
5762 Remote targets now use a data cache to speed up communication with the
5763 remote side. The data cache could lead to incorrect results because
5764 it doesn't know about volatile variables, thus making it impossible to
5765 debug targets which use memory mapped I/O devices. `set remotecache
5766 off' turns the the data cache off.
5768 * Remote targets may have threads
5770 The standard remote protocol now includes support for multiple threads
5771 in the target system, using new protocol commands 'H' and 'T'. See
5772 gdb/remote.c for details.
5776 If GDB is configured with `--enable-netrom', then it will include
5777 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5778 acts as though it is a bank of ROM on the target board, but you can
5779 write into it over the network. GDB's support consists only of
5780 support for fast loading into the emulated ROM; to debug, you must use
5781 another protocol, such as standard remote protocol. The usual
5782 sequence is something like
5784 target nrom <netrom-hostname>
5786 target remote <netrom-hostname>:1235
5790 GDB now includes support for the Apple Macintosh, as a host only. It
5791 may be run as either an MPW tool or as a standalone application, and
5792 it can debug through the serial port. All the usual GDB commands are
5793 available, but to the target command, you must supply "serial" as the
5794 device type instead of "/dev/ttyXX". See mpw-README in the main
5795 directory for more information on how to build. The MPW configuration
5796 scripts */mpw-config.in support only a few targets, and only the
5797 mips-idt-ecoff target has been tested.
5801 GDB configuration now uses autoconf. This is not user-visible,
5802 but does simplify configuration and building.
5806 GDB now supports hpux10.
5808 *** Changes in GDB-4.14:
5810 * New native configurations
5812 x86 FreeBSD i[345]86-*-freebsd
5813 x86 NetBSD i[345]86-*-netbsd
5814 NS32k NetBSD ns32k-*-netbsd
5815 Sparc NetBSD sparc-*-netbsd
5819 A29K VxWorks a29k-*-vxworks
5820 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5821 CPU32 EST-300 emulator m68*-*-est*
5822 PowerPC ELF powerpc-*-elf
5825 * Alpha OSF/1 support for procfs
5827 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5828 possible to attach to running processes. As the mounting of the /proc
5829 filesystem is optional on the Alpha, GDB automatically determines
5830 the availability of /proc during startup. This can lead to problems
5831 if /proc is unmounted after GDB has been started.
5833 * Arguments to user-defined commands
5835 User commands may accept up to 10 arguments separated by whitespace.
5836 Arguments are accessed within the user command via $arg0..$arg9. A
5839 print $arg0 + $arg1 + $arg2
5841 To execute the command use:
5844 Defines the command "adder" which prints the sum of its three arguments.
5845 Note the arguments are text substitutions, so they may reference variables,
5846 use complex expressions, or even perform inferior function calls.
5848 * New `if' and `while' commands
5850 This makes it possible to write more sophisticated user-defined
5851 commands. Both commands take a single argument, which is the
5852 expression to evaluate, and must be followed by the commands to
5853 execute, one per line, if the expression is nonzero, the list being
5854 terminated by the word `end'. The `if' command list may include an
5855 `else' word, which causes the following commands to be executed only
5856 if the expression is zero.
5858 * Fortran source language mode
5860 GDB now includes partial support for Fortran 77. It will recognize
5861 Fortran programs and can evaluate a subset of Fortran expressions, but
5862 variables and functions may not be handled correctly. GDB will work
5863 with G77, but does not yet know much about symbols emitted by other
5866 * Better HPUX support
5868 Most debugging facilities now work on dynamic executables for HPPAs
5869 running hpux9 or later. You can attach to running dynamically linked
5870 processes, but by default the dynamic libraries will be read-only, so
5871 for instance you won't be able to put breakpoints in them. To change
5872 that behavior do the following before running the program:
5878 This will cause the libraries to be mapped private and read-write.
5879 To revert to the normal behavior, do this:
5885 You cannot set breakpoints or examine data in the library until after
5886 the library is loaded if the function/data symbols do not have
5889 GDB can now also read debug symbols produced by the HP C compiler on
5890 HPPAs (sorry, no C++, Fortran or 68k support).
5892 * Target byte order now dynamically selectable
5894 You can choose which byte order to use with a target system, via the
5895 commands "set endian big" and "set endian little", and you can see the
5896 current setting by using "show endian". You can also give the command
5897 "set endian auto", in which case GDB will use the byte order
5898 associated with the executable. Currently, only embedded MIPS
5899 configurations support dynamic selection of target byte order.
5901 * New DOS host serial code
5903 This version uses DPMI interrupts to handle buffered I/O, so you
5904 no longer need to run asynctsr when debugging boards connected to
5907 *** Changes in GDB-4.13:
5909 * New "complete" command
5911 This lists all the possible completions for the rest of the line, if it
5912 were to be given as a command itself. This is intended for use by emacs.
5914 * Trailing space optional in prompt
5916 "set prompt" no longer adds a space for you after the prompt you set. This
5917 allows you to set a prompt which ends in a space or one that does not.
5919 * Breakpoint hit counts
5921 "info break" now displays a count of the number of times the breakpoint
5922 has been hit. This is especially useful in conjunction with "ignore"; you
5923 can ignore a large number of breakpoint hits, look at the breakpoint info
5924 to see how many times the breakpoint was hit, then run again, ignoring one
5925 less than that number, and this will get you quickly to the last hit of
5928 * Ability to stop printing at NULL character
5930 "set print null-stop" will cause GDB to stop printing the characters of
5931 an array when the first NULL is encountered. This is useful when large
5932 arrays actually contain only short strings.
5934 * Shared library breakpoints
5936 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5937 breakpoints in shared libraries before the executable is run.
5939 * Hardware watchpoints
5941 There is a new hardware breakpoint for the watch command for sparclite
5942 targets. See gdb/sparclite/hw_breakpoint.note.
5944 Hardware watchpoints are also now supported under GNU/Linux.
5948 Annotations have been added. These are for use with graphical interfaces,
5949 and are still experimental. Currently only gdba.el uses these.
5951 * Improved Irix 5 support
5953 GDB now works properly with Irix 5.2.
5955 * Improved HPPA support
5957 GDB now works properly with the latest GCC and GAS.
5959 * New native configurations
5961 Sequent PTX4 i[34]86-sequent-ptx4
5962 HPPA running OSF/1 hppa*-*-osf*
5963 Atari TT running SVR4 m68*-*-sysv4*
5964 RS/6000 LynxOS rs6000-*-lynxos*
5968 OS/9000 i[34]86-*-os9k
5969 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5972 * Hitachi SH7000 and E7000-PC ICE support
5974 There is now support for communicating with the Hitachi E7000-PC ICE.
5975 This is available automatically when GDB is configured for the SH.
5979 As usual, a variety of small fixes and improvements, both generic
5980 and configuration-specific. See the ChangeLog for more detail.
5982 *** Changes in GDB-4.12:
5984 * Irix 5 is now supported
5988 GDB-4.12 on the HPPA has a number of changes which make it unable
5989 to debug the output from the currently released versions of GCC and
5990 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5991 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5992 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
5995 *** Changes in GDB-4.11:
5997 * User visible changes:
6001 The "set remotedebug" option is now consistent between the mips remote
6002 target, remote targets using the gdb-specific protocol, UDI (AMD's
6003 debug protocol for the 29k) and the 88k bug monitor. It is now an
6004 integer specifying a debug level (normally 0 or 1, but 2 means more
6005 debugging info for the mips target).
6007 * DEC Alpha native support
6009 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6010 debug info, but GDB works fairly well with the DEC compiler and should
6011 work with a future GCC release. See the README file for a few
6012 Alpha-specific notes.
6014 * Preliminary thread implementation
6016 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6018 * LynxOS native and target support for 386
6020 This release has been hosted on LynxOS 2.2, and also can be configured
6021 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6024 * Improvements in C++ mangling/demangling.
6026 This release has much better g++ debugging, specifically in name
6027 mangling/demangling, virtual function calls, print virtual table,
6028 call methods, ...etc.
6030 *** Changes in GDB-4.10:
6032 * User visible changes:
6034 Remote debugging using the GDB-specific (`target remote') protocol now
6035 supports the `load' command. This is only useful if you have some
6036 other way of getting the stub to the target system, and you can put it
6037 somewhere in memory where it won't get clobbered by the download.
6039 Filename completion now works.
6041 When run under emacs mode, the "info line" command now causes the
6042 arrow to point to the line specified. Also, "info line" prints
6043 addresses in symbolic form (as well as hex).
6045 All vxworks based targets now support a user settable option, called
6046 vxworks-timeout. This option represents the number of seconds gdb
6047 should wait for responses to rpc's. You might want to use this if
6048 your vxworks target is, perhaps, a slow software simulator or happens
6049 to be on the far side of a thin network line.
6053 This release contains support for using a DEC alpha as a GDB host for
6054 cross debugging. Native alpha debugging is not supported yet.
6057 *** Changes in GDB-4.9:
6061 This is the first GDB release which is accompanied by a matching testsuite.
6062 The testsuite requires installation of dejagnu, which should be available
6063 via ftp from most sites that carry GNU software.
6067 'Cfront' style demangling has had its name changed to 'ARM' style, to
6068 emphasize that it was written from the specifications in the C++ Annotated
6069 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6070 disclaimers, it still generated too much confusion with users attempting to
6071 use gdb with AT&T cfront.
6075 GDB now uses a standard remote interface to a simulator library.
6076 So far, the library contains simulators for the Zilog Z8001/2, the
6077 Hitachi H8/300, H8/500 and Super-H.
6079 * New targets supported
6081 H8/300 simulator h8300-hitachi-hms or h8300hms
6082 H8/500 simulator h8500-hitachi-hms or h8500hms
6083 SH simulator sh-hitachi-hms or sh
6084 Z8000 simulator z8k-zilog-none or z8ksim
6085 IDT MIPS board over serial line mips-idt-ecoff
6087 Cross-debugging to GO32 targets is supported. It requires a custom
6088 version of the i386-stub.c module which is integrated with the
6089 GO32 memory extender.
6091 * New remote protocols
6093 MIPS remote debugging protocol.
6095 * New source languages supported
6097 This version includes preliminary support for Chill, a Pascal like language
6098 used by telecommunications companies. Chill support is also being integrated
6099 into the GNU compiler, but we don't know when it will be publically available.
6102 *** Changes in GDB-4.8:
6104 * HP Precision Architecture supported
6106 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6107 version of this support was available as a set of patches from the
6108 University of Utah. GDB does not support debugging of programs
6109 compiled with the HP compiler, because HP will not document their file
6110 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6111 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6113 Many problems in the preliminary version have been fixed.
6115 * Faster and better demangling
6117 We have improved template demangling and fixed numerous bugs in the GNU style
6118 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6119 character types (wchar_t) are now supported. Demangling of each symbol is now
6120 only done once, and is cached when the symbol table for a file is read in.
6121 This results in a small increase in memory usage for C programs, a moderate
6122 increase in memory usage for C++ programs, and a fantastic speedup in
6125 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6126 from the specifications in the Annotated Reference Manual, which AT&T's
6127 compiler does not actually implement.
6129 * G++ multiple inheritance compiler problem
6131 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6132 inheritance lattices was reworked to properly discover ambiguities. We
6133 recently found an example which causes this new algorithm to fail in a
6134 very subtle way, producing bad debug information for those classes.
6135 The file 'gcc.patch' (in this directory) can be applied to gcc to
6136 circumvent the problem. A future GCC release will contain a complete
6139 The previous G++ debug info problem (mentioned below for the gdb-4.7
6140 release) is fixed in gcc version 2.3.2.
6142 * Improved configure script
6144 The `configure' script will now attempt to guess your system type if
6145 you don't supply a host system type. The old scheme of supplying a
6146 host system triplet is preferable over using this. All the magic is
6147 done in the new `config.guess' script. Examine it for details.
6149 We have also brought our configure script much more in line with the FSF's
6150 version. It now supports the --with-xxx options. In particular,
6151 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6152 The resulting GDB will not be able to read arbitrary object file formats --
6153 only the format ``expected'' to be used on the configured target system.
6154 We hope to make this the default in a future release.
6156 * Documentation improvements
6158 There's new internal documentation on how to modify GDB, and how to
6159 produce clean changes to the code. We implore people to read it
6160 before submitting changes.
6162 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6163 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6164 `info' files are also provided. To build `info' files from scratch,
6165 you will need the latest `makeinfo' release, which will be available in
6166 a future texinfo-X.Y release.
6168 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6169 We're not sure exactly which versions have this problem, but it has
6170 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6171 or better. If that isn't possible, there is a patch in
6172 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6173 around this problem.
6177 GDB now supports array constants that can be used in expressions typed in by
6178 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6179 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6182 The new directory `gdb/sparclite' contains a program that demonstrates
6183 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6185 * New native hosts supported
6187 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6188 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6190 * New targets supported
6192 AMD 29k family via UDI a29k-amd-udi or udi29k
6194 * New file formats supported
6196 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6197 HPUX core files, and SCO 3.2v2 core files.
6201 Attaching to processes now works again; thanks for the many bug reports.
6203 We have also stomped on a bunch of core dumps caused by
6204 printf_filtered("%s") problems.
6206 We eliminated a copyright problem on the rpc and ptrace header files
6207 for VxWorks, which was discovered at the last minute during the 4.7
6208 release. You should now be able to build a VxWorks GDB.
6210 You can now interrupt gdb while an attached process is running. This
6211 will cause the attached process to stop, and give control back to GDB.
6213 We fixed problems caused by using too many file descriptors
6214 for reading symbols from object files and libraries. This was
6215 especially a problem for programs that used many (~100) shared
6218 The `step' command now only enters a subroutine if there is line number
6219 information for the subroutine. Otherwise it acts like the `next'
6220 command. Previously, `step' would enter subroutines if there was
6221 any debugging information about the routine. This avoids problems
6222 when using `cc -g1' on MIPS machines.
6224 * Internal improvements
6226 GDB's internal interfaces have been improved to make it easier to support
6227 debugging of multiple languages in the future.
6229 GDB now uses a common structure for symbol information internally.
6230 Minimal symbols (derived from linkage symbols in object files), partial
6231 symbols (from a quick scan of debug information), and full symbols
6232 contain a common subset of information, making it easier to write
6233 shared code that handles any of them.
6235 * New command line options
6237 We now accept --silent as an alias for --quiet.
6241 The memory-mapped-malloc library is now licensed under the GNU Library
6242 General Public License.
6244 *** Changes in GDB-4.7:
6246 * Host/native/target split
6248 GDB has had some major internal surgery to untangle the support for
6249 hosts and remote targets. Now, when you configure GDB for a remote
6250 target, it will no longer load in all of the support for debugging
6251 local programs on the host. When fully completed and tested, this will
6252 ensure that arbitrary host/target combinations are possible.
6254 The primary conceptual shift is to separate the non-portable code in
6255 GDB into three categories. Host specific code is required any time GDB
6256 is compiled on that host, regardless of the target. Target specific
6257 code relates to the peculiarities of the target, but can be compiled on
6258 any host. Native specific code is everything else: it can only be
6259 built when the host and target are the same system. Child process
6260 handling and core file support are two common `native' examples.
6262 GDB's use of /proc for controlling Unix child processes is now cleaner.
6263 It has been split out into a single module under the `target_ops' vector,
6264 plus two native-dependent functions for each system that uses /proc.
6266 * New hosts supported
6268 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6269 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6270 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6272 * New targets supported
6274 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6275 68030 and CPU32 m68030-*-*, m68332-*-*
6277 * New native hosts supported
6279 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6280 (386bsd is not well tested yet)
6281 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6283 * New file formats supported
6285 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6286 supports reading of `a.out.adobe' object files, which are an a.out
6287 format extended with minimal information about multiple sections.
6291 `show copying' is the same as the old `info copying'.
6292 `show warranty' is the same as `info warrantee'.
6293 These were renamed for consistency. The old commands continue to work.
6295 `info handle' is a new alias for `info signals'.
6297 You can now define pre-command hooks, which attach arbitrary command
6298 scripts to any command. The commands in the hook will be executed
6299 prior to the user's command. You can also create a hook which will be
6300 executed whenever the program stops. See gdb.texinfo.
6304 We now deal with Cfront style name mangling, and can even extract type
6305 info from mangled symbols. GDB can automatically figure out which
6306 symbol mangling style your C++ compiler uses.
6308 Calling of methods and virtual functions has been improved as well.
6312 The crash that occured when debugging Sun Ansi-C compiled binaries is
6313 fixed. This was due to mishandling of the extra N_SO stabs output
6316 We also finally got Ultrix 4.2 running in house, and fixed core file
6317 support, with help from a dozen people on the net.
6319 John M. Farrell discovered that the reason that single-stepping was so
6320 slow on all of the Mips based platforms (primarily SGI and DEC) was
6321 that we were trying to demangle and lookup a symbol used for internal
6322 purposes on every instruction that was being stepped through. Changing
6323 the name of that symbol so that it couldn't be mistaken for a C++
6324 mangled symbol sped things up a great deal.
6326 Rich Pixley sped up symbol lookups in general by getting much smarter
6327 about when C++ symbol mangling is necessary. This should make symbol
6328 completion (TAB on the command line) much faster. It's not as fast as
6329 we'd like, but it's significantly faster than gdb-4.6.
6333 A new user controllable variable 'call_scratch_address' can
6334 specify the location of a scratch area to be used when GDB
6335 calls a function in the target. This is necessary because the
6336 usual method of putting the scratch area on the stack does not work
6337 in systems that have separate instruction and data spaces.
6339 We integrated changes to support the 29k UDI (Universal Debugger
6340 Interface), but discovered at the last minute that we didn't have all
6341 of the appropriate copyright paperwork. We are working with AMD to
6342 resolve this, and hope to have it available soon.
6346 We have sped up the remote serial line protocol, especially for targets
6347 with lots of registers. It now supports a new `expedited status' ('T')
6348 message which can be used in place of the existing 'S' status message.
6349 This allows the remote stub to send only the registers that GDB
6350 needs to make a quick decision about single-stepping or conditional
6351 breakpoints, eliminating the need to fetch the entire register set for
6352 each instruction being stepped through.
6354 The GDB remote serial protocol now implements a write-through cache for
6355 registers, only re-reading the registers if the target has run.
6357 There is also a new remote serial stub for SPARC processors. You can
6358 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6359 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6360 processor with a serial port.
6364 Configure.in files have become much easier to read and modify. A new
6365 `table driven' format makes it more obvious what configurations are
6366 supported, and what files each one uses.
6370 There is a new opcodes library which will eventually contain all of the
6371 disassembly routines and opcode tables. At present, it only contains
6372 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6373 disassembler (binutils/objdump) to share these routines.
6375 The libiberty library is now copylefted under the GNU Library General
6376 Public License. This allows more liberal use, and was done so libg++
6377 can use it. This makes no difference to GDB, since the Library License
6378 grants all the rights from the General Public License.
6382 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6383 reference to the stabs symbol info used by the debugger. It is (as far
6384 as we know) the only published document on this fascinating topic. We
6385 encourage you to read it, compare it to the stabs information on your
6386 system, and send improvements on the document in general (to
6387 bug-gdb@prep.ai.mit.edu).
6389 And, of course, many bugs have been fixed.
6392 *** Changes in GDB-4.6:
6394 * Better support for C++ function names
6396 GDB now accepts as input the "demangled form" of C++ overloaded function
6397 names and member function names, and can do command completion on such names
6398 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6399 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6400 Make use of command completion, it is your friend.
6402 GDB also now accepts a variety of C++ mangled symbol formats. They are
6403 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6404 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6405 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6406 for the list of formats.
6408 * G++ symbol mangling problem
6410 Recent versions of gcc have a bug in how they emit debugging information for
6411 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6412 directory) can be applied to gcc to fix the problem. Alternatively, if you
6413 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6414 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6415 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6418 * New 'maintenance' command
6420 All of the commands related to hacking GDB internals have been moved out of
6421 the main command set, and now live behind the 'maintenance' command. This
6422 can also be abbreviated as 'mt'. The following changes were made:
6424 dump-me -> maintenance dump-me
6425 info all-breakpoints -> maintenance info breakpoints
6426 printmsyms -> maintenance print msyms
6427 printobjfiles -> maintenance print objfiles
6428 printpsyms -> maintenance print psymbols
6429 printsyms -> maintenance print symbols
6431 The following commands are new:
6433 maintenance demangle Call internal GDB demangler routine to
6434 demangle a C++ link name and prints the result.
6435 maintenance print type Print a type chain for a given symbol
6437 * Change to .gdbinit file processing
6439 We now read the $HOME/.gdbinit file before processing the argv arguments
6440 (e.g. reading symbol files or core files). This allows global parameters to
6441 be set, which will apply during the symbol reading. The ./.gdbinit is still
6442 read after argv processing.
6444 * New hosts supported
6446 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6448 GNU/Linux support i386-unknown-linux or linux
6450 We are also including code to support the HP/PA running BSD and HPUX. This
6451 is almost guaranteed not to work, as we didn't have time to test or build it
6452 for this release. We are including it so that the more adventurous (or
6453 masochistic) of you can play with it. We also had major problems with the
6454 fact that the compiler that we got from HP doesn't support the -g option.
6457 * New targets supported
6459 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6461 * More smarts about finding #include files
6463 GDB now remembers the compilation directory for all include files, and for
6464 all files from which C is generated (like yacc and lex sources). This
6465 greatly improves GDB's ability to find yacc/lex sources, and include files,
6466 especially if you are debugging your program from a directory different from
6467 the one that contains your sources.
6469 We also fixed a bug which caused difficulty with listing and setting
6470 breakpoints in include files which contain C code. (In the past, you had to
6471 try twice in order to list an include file that you hadn't looked at before.)
6473 * Interesting infernals change
6475 GDB now deals with arbitrary numbers of sections, where the symbols for each
6476 section must be relocated relative to that section's landing place in the
6477 target's address space. This work was needed to support ELF with embedded
6478 stabs used by Solaris-2.0.
6480 * Bug fixes (of course!)
6482 There have been loads of fixes for the following things:
6483 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6484 i960, stabs, DOS(GO32), procfs, etc...
6486 See the ChangeLog for details.
6488 *** Changes in GDB-4.5:
6490 * New machines supported (host and target)
6492 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6494 SGI Irix-4.x mips-sgi-irix4 or iris4
6496 * New malloc package
6498 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6499 Mmalloc is capable of handling mutiple heaps of memory. It is also
6500 capable of saving a heap to a file, and then mapping it back in later.
6501 This can be used to greatly speedup the startup of GDB by using a
6502 pre-parsed symbol table which lives in a mmalloc managed heap. For
6503 more details, please read mmalloc/mmalloc.texi.
6507 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6508 'help info proc' for details.
6510 * MIPS ecoff symbol table format
6512 The code that reads MIPS symbol table format is now supported on all hosts.
6513 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6516 * File name changes for MS-DOS
6518 Many files in the config directories have been renamed to make it easier to
6519 support GDB on MS-DOSe systems (which have very restrictive file name
6520 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6521 environment) is close to working but has some remaining problems. Note
6522 that debugging of DOS programs is not supported, due to limitations
6523 in the ``operating system'', but it can be used to host cross-debugging.
6525 * Cross byte order fixes
6527 Many fixes have been made to support cross debugging of Sparc and MIPS
6528 targets from hosts whose byte order differs.
6530 * New -mapped and -readnow options
6532 If memory-mapped files are available on your system through the 'mmap'
6533 system call, you can use the -mapped option on the `file' or
6534 `symbol-file' commands to cause GDB to write the symbols from your
6535 program into a reusable file. If the program you are debugging is
6536 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6537 Future GDB debugging sessions will notice the presence of this file,
6538 and will quickly map in symbol information from it, rather than reading
6539 the symbol table from the executable program. Using the '-mapped'
6540 option in a GDB `file' or `symbol-file' command has the same effect as
6541 starting GDB with the '-mapped' command-line option.
6543 You can cause GDB to read the entire symbol table immediately by using
6544 the '-readnow' option with any of the commands that load symbol table
6545 information (or on the GDB command line). This makes the command
6546 slower, but makes future operations faster.
6548 The -mapped and -readnow options are typically combined in order to
6549 build a `fred.syms' file that contains complete symbol information.
6550 A simple GDB invocation to do nothing but build a `.syms' file for future
6553 gdb -batch -nx -mapped -readnow programname
6555 The `.syms' file is specific to the host machine on which GDB is run.
6556 It holds an exact image of GDB's internal symbol table. It cannot be
6557 shared across multiple host platforms.
6559 * longjmp() handling
6561 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6562 siglongjmp() without losing control. This feature has not yet been ported to
6563 all systems. It currently works on many 386 platforms, all MIPS-based
6564 platforms (SGI, DECstation, etc), and Sun3/4.
6568 Preliminary work has been put in to support the new Solaris OS from Sun. At
6569 this time, it can control and debug processes, but it is not capable of
6574 As always, many many bug fixes. The major areas were with g++, and mipsread.
6575 People using the MIPS-based platforms should experience fewer mysterious
6576 crashes and trashed symbol tables.
6578 *** Changes in GDB-4.4:
6580 * New machines supported (host and target)
6582 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6584 BSD Reno on Vax vax-dec-bsd
6585 Ultrix on Vax vax-dec-ultrix
6587 * New machines supported (target)
6589 AMD 29000 embedded, using EBMON a29k-none-none
6593 GDB continues to improve its handling of C++. `References' work better.
6594 The demangler has also been improved, and now deals with symbols mangled as
6595 per the Annotated C++ Reference Guide.
6597 GDB also now handles `stabs' symbol information embedded in MIPS
6598 `ecoff' symbol tables. Since the ecoff format was not easily
6599 extensible to handle new languages such as C++, this appeared to be a
6600 good way to put C++ debugging info into MIPS binaries. This option
6601 will be supported in the GNU C compiler, version 2, when it is
6604 * New features for SVR4
6606 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6607 shared libraries. Debugging dynamically linked programs should present
6608 only minor differences from debugging statically linked programs.
6610 The `info proc' command will print out information about any process
6611 on an SVR4 system (including the one you are debugging). At the moment,
6612 it prints the address mappings of the process.
6614 If you bring up GDB on another SVR4 system, please send mail to
6615 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6617 * Better dynamic linking support in SunOS
6619 Reading symbols from shared libraries which contain debugging symbols
6620 now works properly. However, there remain issues such as automatic
6621 skipping of `transfer vector' code during function calls, which
6622 make it harder to debug code in a shared library, than to debug the
6623 same code linked statically.
6627 GDB is now using the latest `getopt' routines from the FSF. This
6628 version accepts the -- prefix for options with long names. GDB will
6629 continue to accept the old forms (-option and +option) as well.
6630 Various single letter abbreviations for options have been explicity
6631 added to the option table so that they won't get overshadowed in the
6632 future by other options that begin with the same letter.
6636 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6637 Many assorted bugs have been handled. Many more remain to be handled.
6638 See the various ChangeLog files (primarily in gdb and bfd) for details.
6641 *** Changes in GDB-4.3:
6643 * New machines supported (host and target)
6645 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6646 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6647 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6649 * Almost SCO Unix support
6651 We had hoped to support:
6652 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6653 (except for core file support), but we discovered very late in the release
6654 that it has problems with process groups that render gdb unusable. Sorry
6655 about that. I encourage people to fix it and post the fixes.
6657 * Preliminary ELF and DWARF support
6659 GDB can read ELF object files on System V Release 4, and can handle
6660 debugging records for C, in DWARF format, in ELF files. This support
6661 is preliminary. If you bring up GDB on another SVR4 system, please
6662 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6667 GDB now uses the latest `readline' library. One user-visible change
6668 is that two tabs will list possible command completions, which previously
6669 required typing M-? (meta-question mark, or ESC ?).
6673 The `stepi' bug that many of you noticed has been squashed.
6674 Many bugs in C++ have been handled. Many more remain to be handled.
6675 See the various ChangeLog files (primarily in gdb and bfd) for details.
6677 * State of the MIPS world (in case you wondered):
6679 GDB can understand the symbol tables emitted by the compilers
6680 supplied by most vendors of MIPS-based machines, including DEC. These
6681 symbol tables are in a format that essentially nobody else uses.
6683 Some versions of gcc come with an assembler post-processor called
6684 mips-tfile. This program is required if you want to do source-level
6685 debugging of gcc-compiled programs. I believe FSF does not ship
6686 mips-tfile with gcc version 1, but it will eventually come with gcc
6689 Debugging of g++ output remains a problem. g++ version 1.xx does not
6690 really support it at all. (If you're lucky, you should be able to get
6691 line numbers and stack traces to work, but no parameters or local
6692 variables.) With some work it should be possible to improve the
6695 When gcc version 2 is released, you will have somewhat better luck.
6696 However, even then you will get confusing results for inheritance and
6699 We will eventually provide full debugging of g++ output on
6700 DECstations. This will probably involve some kind of stabs-in-ecoff
6701 encapulation, but the details have not been worked out yet.
6704 *** Changes in GDB-4.2:
6706 * Improved configuration
6708 Only one copy of `configure' exists now, and it is not self-modifying.
6709 Porting BFD is simpler.
6713 The `step' and `next' commands now only stop at the first instruction
6714 of a source line. This prevents the multiple stops that used to occur
6715 in switch statements, for-loops, etc. `Step' continues to stop if a
6716 function that has debugging information is called within the line.
6720 Lots of small bugs fixed. More remain.
6722 * New host supported (not target)
6724 Intel 386 PC clone running Mach i386-none-mach
6727 *** Changes in GDB-4.1:
6729 * Multiple source language support
6731 GDB now has internal scaffolding to handle several source languages.
6732 It determines the type of each source file from its filename extension,
6733 and will switch expression parsing and number formatting to match the
6734 language of the function in the currently selected stack frame.
6735 You can also specifically set the language to be used, with
6736 `set language c' or `set language modula-2'.
6740 GDB now has preliminary support for the GNU Modula-2 compiler,
6741 currently under development at the State University of New York at
6742 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6743 continue through the fall of 1991 and into 1992.
6745 Other Modula-2 compilers are currently not supported, and attempting to
6746 debug programs compiled with them will likely result in an error as the
6747 symbol table is read. Feel free to work on it, though!
6749 There are hooks in GDB for strict type checking and range checking,
6750 in the `Modula-2 philosophy', but they do not currently work.
6754 GDB can now write to executable and core files (e.g. patch
6755 a variable's value). You must turn this switch on, specify
6756 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6757 by assigning a new value to a variable. Modifications take
6760 * Automatic SunOS shared library reading
6762 When you run your program, GDB automatically determines where its
6763 shared libraries (if any) have been loaded, and reads their symbols.
6764 The `share' command is no longer needed. This also works when
6765 examining core files.
6769 You can specify the number of lines that the `list' command shows.
6772 * New machines supported (host and target)
6774 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6775 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6776 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6778 * New hosts supported (not targets)
6780 IBM RT/PC: romp-ibm-aix or rtpc
6782 * New targets supported (not hosts)
6784 AMD 29000 embedded with COFF a29k-none-coff
6785 AMD 29000 embedded with a.out a29k-none-aout
6786 Ultracomputer remote kernel debug a29k-nyu-kern
6788 * New remote interfaces
6794 *** Changes in GDB-4.0:
6798 Wide output is wrapped at good places to make the output more readable.
6800 Gdb now supports cross-debugging from a host machine of one type to a
6801 target machine of another type. Communication with the target system
6802 is over serial lines. The ``target'' command handles connecting to the
6803 remote system; the ``load'' command will download a program into the
6804 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6805 also supports debugging of realtime processes running under VxWorks,
6806 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6807 stub on the target system.
6809 New CPUs supported include the AMD 29000 and Intel 960.
6811 GDB now reads object files and symbol tables via a ``binary file''
6812 library, which allows a single copy of GDB to debug programs of multiple
6813 object file types such as a.out and coff.
6815 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6816 refcard.dvi and refcard.ps are available to format it).
6819 * Control-Variable user interface simplified
6821 All variables that control the operation of the debugger can be set
6822 by the ``set'' command, and displayed by the ``show'' command.
6824 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6825 ``Show prompt'' produces the response:
6826 Gdb's prompt is new-gdb=>.
6828 What follows are the NEW set commands. The command ``help set'' will
6829 print a complete list of old and new set commands. ``help set FOO''
6830 will give a longer description of the variable FOO. ``show'' will show
6831 all of the variable descriptions and their current settings.
6833 confirm on/off: Enables warning questions for operations that are
6834 hard to recover from, e.g. rerunning the program while
6835 it is already running. Default is ON.
6837 editing on/off: Enables EMACS style command line editing
6838 of input. Previous lines can be recalled with
6839 control-P, the current line can be edited with control-B,
6840 you can search for commands with control-R, etc.
6843 history filename NAME: NAME is where the gdb command history
6844 will be stored. The default is .gdb_history,
6845 or the value of the environment variable
6848 history size N: The size, in commands, of the command history. The
6849 default is 256, or the value of the environment variable
6852 history save on/off: If this value is set to ON, the history file will
6853 be saved after exiting gdb. If set to OFF, the
6854 file will not be saved. The default is OFF.
6856 history expansion on/off: If this value is set to ON, then csh-like
6857 history expansion will be performed on
6858 command line input. The default is OFF.
6860 radix N: Sets the default radix for input and output. It can be set
6861 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6862 in the current radix, so "set radix 10" is always a no-op.
6864 height N: This integer value is the number of lines on a page. Default
6865 is 24, the current `stty rows'' setting, or the ``li#''
6866 setting from the termcap entry matching the environment
6869 width N: This integer value is the number of characters on a line.
6870 Default is 80, the current `stty cols'' setting, or the ``co#''
6871 setting from the termcap entry matching the environment
6874 Note: ``set screensize'' is obsolete. Use ``set height'' and
6875 ``set width'' instead.
6877 print address on/off: Print memory addresses in various command displays,
6878 such as stack traces and structure values. Gdb looks
6879 more ``symbolic'' if you turn this off; it looks more
6880 ``machine level'' with it on. Default is ON.
6882 print array on/off: Prettyprint arrays. New convenient format! Default
6885 print demangle on/off: Print C++ symbols in "source" form if on,
6888 print asm-demangle on/off: Same, for assembler level printouts
6891 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6894 * Support for Epoch Environment.
6896 The epoch environment is a version of Emacs v18 with windowing. One
6897 new command, ``inspect'', is identical to ``print'', except that if you
6898 are running in the epoch environment, the value is printed in its own
6902 * Support for Shared Libraries
6904 GDB can now debug programs and core files that use SunOS shared libraries.
6905 Symbols from a shared library cannot be referenced
6906 before the shared library has been linked with the program (this
6907 happens after you type ``run'' and before the function main() is entered).
6908 At any time after this linking (including when examining core files
6909 from dynamically linked programs), gdb reads the symbols from each
6910 shared library when you type the ``sharedlibrary'' command.
6911 It can be abbreviated ``share''.
6913 sharedlibrary REGEXP: Load shared object library symbols for files
6914 matching a unix regular expression. No argument
6915 indicates to load symbols for all shared libraries.
6917 info sharedlibrary: Status of loaded shared libraries.
6922 A watchpoint stops execution of a program whenever the value of an
6923 expression changes. Checking for this slows down execution
6924 tremendously whenever you are in the scope of the expression, but is
6925 quite useful for catching tough ``bit-spreader'' or pointer misuse
6926 problems. Some machines such as the 386 have hardware for doing this
6927 more quickly, and future versions of gdb will use this hardware.
6929 watch EXP: Set a watchpoint (breakpoint) for an expression.
6931 info watchpoints: Information about your watchpoints.
6933 delete N: Deletes watchpoint number N (same as breakpoints).
6934 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6935 enable N: Re-enables watchpoint number N (same as breakpoints).
6938 * C++ multiple inheritance
6940 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6943 * C++ exception handling
6945 Gdb now supports limited C++ exception handling. Besides the existing
6946 ability to breakpoint on an exception handler, gdb can breakpoint on
6947 the raising of an exception (before the stack is peeled back to the
6950 catch FOO: If there is a FOO exception handler in the dynamic scope,
6951 set a breakpoint to catch exceptions which may be raised there.
6952 Multiple exceptions (``catch foo bar baz'') may be caught.
6954 info catch: Lists all exceptions which may be caught in the
6955 current stack frame.
6958 * Minor command changes
6960 The command ``call func (arg, arg, ...)'' now acts like the print
6961 command, except it does not print or save a value if the function's result
6962 is void. This is similar to dbx usage.
6964 The ``up'' and ``down'' commands now always print the frame they end up
6965 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6966 frames without printing.
6968 * New directory command
6970 'dir' now adds directories to the FRONT of the source search path.
6971 The path starts off empty. Source files that contain debug information
6972 about the directory in which they were compiled can be found even
6973 with an empty path; Sun CC and GCC include this information. If GDB can't
6974 find your source file in the current directory, type "dir .".
6976 * Configuring GDB for compilation
6978 For normal use, type ``./configure host''. See README or gdb.texinfo
6981 GDB now handles cross debugging. If you are remotely debugging between
6982 two different machines, type ``./configure host -target=targ''.
6983 Host is the machine where GDB will run; targ is the machine
6984 where the program that you are debugging will run.