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 * Removed targets and native configurations
33 m88k running OpenBSD m88*-*-openbsd*
34 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
35 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
36 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
38 *** Changes in GDB 8.1
40 * GDB now supports dynamically creating arbitrary register groups specified
41 in XML target descriptions. This allows for finer grain grouping of
42 registers on systems with a large amount of registers.
44 * The 'ptype' command now accepts a '/o' flag, which prints the
45 offsets and sizes of fields in a struct, like the pahole(1) tool.
47 * New "--readnever" command line option instructs GDB to not read each
48 symbol file's symbolic debug information. This makes startup faster
49 but at the expense of not being able to perform symbolic debugging.
50 This option is intended for use cases where symbolic debugging will
51 not be used, e.g., when you only need to dump the debuggee's core.
53 * GDB now uses the GNU MPFR library, if available, to emulate target
54 floating-point arithmetic during expression evaluation when the target
55 uses different floating-point formats than the host. At least version
56 3.1 of GNU MPFR is required.
58 * GDB now supports access to the guarded-storage-control registers and the
59 software-based guarded-storage broadcast control registers on IBM z14.
61 * On Unix systems, GDB now supports transmitting environment variables
62 that are to be set or unset to GDBserver. These variables will
63 affect the environment to be passed to the remote inferior.
65 To inform GDB of environment variables that are to be transmitted to
66 GDBserver, use the "set environment" command. Only user set
67 environment variables are sent to GDBserver.
69 To inform GDB of environment variables that are to be unset before
70 the remote inferior is started by the GDBserver, use the "unset
73 * Completion improvements
75 ** GDB can now complete function parameters in linespecs and
76 explicit locations without quoting. When setting breakpoints,
77 quoting around functions names to help with TAB-completion is
78 generally no longer necessary. For example, this now completes
81 (gdb) b function(in[TAB]
84 Related, GDB is no longer confused with completing functions in
85 C++ anonymous namespaces:
88 (gdb) b (anonymous namespace)::[TAB][TAB]
89 (anonymous namespace)::a_function()
90 (anonymous namespace)::b_function()
92 ** GDB now has much improved linespec and explicit locations TAB
93 completion support, that better understands what you're
94 completing and offers better suggestions. For example, GDB no
95 longer offers data symbols as possible completions when you're
98 ** GDB now TAB-completes label symbol names.
100 ** The "complete" command now mimics TAB completion accurately.
102 * New command line options (gcore)
105 Dump all memory mappings.
107 * Breakpoints on C++ functions are now set on all scopes by default
109 By default, breakpoints on functions/methods are now interpreted as
110 specifying all functions with the given name ignoring missing
111 leading scopes (namespaces and classes).
113 For example, assuming a C++ program with symbols named:
118 both commands "break func()" and "break B::func()" set a breakpoint
121 You can use the new flag "-qualified" to override this. This makes
122 GDB interpret the specified function name as a complete
123 fully-qualified name instead. For example, using the same C++
124 program, the "break -q B::func" command sets a breakpoint on
125 "B::func", only. A parameter has been added to the Python
126 gdb.Breakpoint constructor to achieve the same result when creating
127 a breakpoint from Python.
129 * Breakpoints on functions marked with C++ ABI tags
131 GDB can now set breakpoints on functions marked with C++ ABI tags
132 (e.g., [abi:cxx11]). See here for a description of ABI tags:
133 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
135 Functions with a C++11 abi tag are demangled/displayed like this:
137 function[abi:cxx11](int)
140 You can now set a breakpoint on such functions simply as if they had
143 (gdb) b function(int)
145 Or if you need to disambiguate between tags, like:
147 (gdb) b function[abi:other_tag](int)
149 Tab completion was adjusted accordingly as well.
153 ** New events gdb.new_inferior, gdb.inferior_deleted, and
154 gdb.new_thread are emitted. See the manual for further
155 description of these.
157 ** A new function, "gdb.rbreak" has been added to the Python API.
158 This function allows the setting of a large number of breakpoints
159 via a regex pattern in Python. See the manual for further details.
161 ** Python breakpoints can now accept explicit locations. See the
162 manual for a further description of this feature.
165 * New features in the GDB remote stub, GDBserver
167 ** GDBserver is now able to start inferior processes with a
168 specified initial working directory.
170 The user can set the desired working directory to be used from
171 GDB using the new "set cwd" command.
173 ** New "--selftest" command line option runs some GDBserver self
174 tests. These self tests are disabled in releases.
176 ** On Unix systems, GDBserver now does globbing expansion and variable
177 substitution in inferior command line arguments.
179 This is done by starting inferiors using a shell, like GDB does.
180 See "set startup-with-shell" in the user manual for how to disable
181 this from GDB when using "target extended-remote". When using
182 "target remote", you can disable the startup with shell by using the
183 new "--no-startup-with-shell" GDBserver command line option.
185 ** On Unix systems, GDBserver now supports receiving environment
186 variables that are to be set or unset from GDB. These variables
187 will affect the environment to be passed to the inferior.
189 * When catching an Ada exception raised with a message, GDB now prints
190 the message in the catchpoint hit notification. In GDB/MI mode, that
191 information is provided as an extra field named "exception-message"
192 in the *stopped notification.
194 * Trait objects can now be inspected When debugging Rust code. This
195 requires compiler support which will appear in Rust 1.24.
199 QEnvironmentHexEncoded
200 Inform GDBserver of an environment variable that is to be passed to
201 the inferior when starting it.
204 Inform GDBserver of an environment variable that is to be unset
205 before starting the remote inferior.
208 Inform GDBserver that the environment should be reset (i.e.,
209 user-set environment variables should be unset).
212 Indicates whether the inferior must be started with a shell or not.
215 Tell GDBserver that the inferior to be started should use a specific
218 * The "maintenance print c-tdesc" command now takes an optional
219 argument which is the file name of XML target description.
221 * The "maintenance selftest" command now takes an optional argument to
222 filter the tests to be run.
224 * The "enable", and "disable" commands now accept a range of
225 breakpoint locations, e.g. "enable 1.3-5".
230 Set and show the current working directory for the inferior.
233 Set and show compilation command used for compiling and injecting code
234 with the 'compile' commands.
236 set debug separate-debug-file
237 show debug separate-debug-file
238 Control the display of debug output about separate debug file search.
240 set dump-excluded-mappings
241 show dump-excluded-mappings
242 Control whether mappings marked with the VM_DONTDUMP flag should be
243 dumped when generating a core file.
246 List the registered selftests.
249 Start the debugged program stopping at the first instruction.
252 Control display of debugging messages related to OpenRISC targets.
254 set|show print type nested-type-limit
255 Set and show the limit of nesting level for nested types that the
256 type printer will show.
258 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
261 * Safer/improved support for debugging with no debug info
263 GDB no longer assumes functions with no debug information return
266 This means that GDB now refuses to call such functions unless you
267 tell it the function's type, by either casting the call to the
268 declared return type, or by casting the function to a function
269 pointer of the right type, and calling that:
271 (gdb) p getenv ("PATH")
272 'getenv' has unknown return type; cast the call to its declared return type
273 (gdb) p (char *) getenv ("PATH")
274 $1 = 0x7fffffffe "/usr/local/bin:/"...
275 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
276 $2 = 0x7fffffffe "/usr/local/bin:/"...
278 Similarly, GDB no longer assumes that global variables with no debug
279 info have type 'int', and refuses to print the variable's value
280 unless you tell it the variable's type:
283 'var' has unknown type; cast it to its declared type
287 * New native configurations
289 FreeBSD/aarch64 aarch64*-*-freebsd*
290 FreeBSD/arm arm*-*-freebsd*
294 FreeBSD/aarch64 aarch64*-*-freebsd*
295 FreeBSD/arm arm*-*-freebsd*
296 OpenRISC ELF or1k*-*-elf
298 * Removed targets and native configurations
300 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
302 *** Changes in GDB 8.0
304 * GDB now supports access to the PKU register on GNU/Linux. The register is
305 added by the Memory Protection Keys for Userspace feature which will be
306 available in future Intel CPUs.
308 * GDB now supports C++11 rvalue references.
312 ** New functions to start, stop and access a running btrace recording.
313 ** Rvalue references are now supported in gdb.Type.
315 * GDB now supports recording and replaying rdrand and rdseed Intel 64
318 * Building GDB and GDBserver now requires a C++11 compiler.
320 For example, GCC 4.8 or later.
322 It is no longer possible to build GDB or GDBserver with a C
323 compiler. The --disable-build-with-cxx configure option has been
326 * Building GDB and GDBserver now requires GNU make >= 3.81.
328 It is no longer supported to build GDB or GDBserver with another
329 implementation of the make program or an earlier version of GNU make.
331 * Native debugging on MS-Windows supports command-line redirection
333 Command-line arguments used for starting programs on MS-Windows can
334 now include redirection symbols supported by native Windows shells,
335 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
336 as "run", "start", and "set args", as well as the corresponding MI
339 * Support for thread names on MS-Windows.
341 GDB now catches and handles the special exception that programs
342 running on MS-Windows use to assign names to threads in the
345 * Support for Java programs compiled with gcj has been removed.
347 * User commands now accept an unlimited number of arguments.
348 Previously, only up to 10 was accepted.
350 * The "eval" command now expands user-defined command arguments.
352 This makes it easier to process a variable number of arguments:
357 eval "print $arg%d", $i
362 * Target descriptions can now describe registers for sparc32 and sparc64.
364 * GDB now supports DWARF version 5 (debug information format).
365 Its .debug_names index is not yet supported.
367 * New native configurations
369 FreeBSD/mips mips*-*-freebsd
373 Synopsys ARC arc*-*-elf32
374 FreeBSD/mips mips*-*-freebsd
376 * Removed targets and native configurations
378 Alpha running FreeBSD alpha*-*-freebsd*
379 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
384 Erases all the flash memory regions reported by the target.
386 maint print arc arc-instruction address
387 Print internal disassembler information about instruction at a given address.
391 set disassembler-options
392 show disassembler-options
393 Controls the passing of target specific information to the disassembler.
394 If it is necessary to specify more than one disassembler option then
395 multiple options can be placed together into a comma separated list.
396 The default value is the empty string. Currently, the only supported
397 targets are ARM, PowerPC and S/390.
402 Erases all the flash memory regions reported by the target. This is
403 equivalent to the CLI command flash-erase.
405 -file-list-shared-libraries
406 List the shared libraries in the program. This is
407 equivalent to the CLI command "info shared".
410 Catchpoints stopping the program when Ada exceptions are
411 handled. This is equivalent to the CLI command "catch handlers".
413 *** Changes in GDB 7.12
415 * GDB and GDBserver now build with a C++ compiler by default.
417 The --enable-build-with-cxx configure option is now enabled by
418 default. One must now explicitly configure with
419 --disable-build-with-cxx in order to build with a C compiler. This
420 option will be removed in a future release.
422 * GDBserver now supports recording btrace without maintaining an active
425 * GDB now supports a negative repeat count in the 'x' command to examine
426 memory backward from the given address. For example:
429 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
430 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
431 (gdb) x/-5i 0x0000000000400580
432 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
433 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
434 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
435 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
436 0x40057b <main(int, char**)+25>:
437 callq 0x400536 <Func1(int, char const*)>
439 * Fortran: Support structures with fields of dynamic types and
440 arrays of dynamic types.
442 * The symbol dumping maintenance commands have new syntax.
443 maint print symbols [-pc address] [--] [filename]
444 maint print symbols [-objfile objfile] [-source source] [--] [filename]
445 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
446 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
447 maint print msymbols [-objfile objfile] [--] [filename]
449 * GDB now supports multibit bitfields and enums in target register
452 * New Python-based convenience function $_as_string(val), which returns
453 the textual representation of a value. This function is especially
454 useful to obtain the text label of an enum value.
456 * Intel MPX bound violation handling.
458 Segmentation faults caused by a Intel MPX boundary violation
459 now display the kind of violation (upper or lower), the memory
460 address accessed and the memory bounds, along with the usual
461 signal received and code location.
465 Program received signal SIGSEGV, Segmentation fault
466 Upper bound violation while accessing address 0x7fffffffc3b3
467 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
468 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
470 * Rust language support.
471 GDB now supports debugging programs written in the Rust programming
472 language. See https://www.rust-lang.org/ for more information about
475 * Support for running interpreters on specified input/output devices
477 GDB now supports a new mechanism that allows frontends to provide
478 fully featured GDB console views, as a better alternative to
479 building such views on top of the "-interpreter-exec console"
480 command. See the new "new-ui" command below. With that command,
481 frontends can now start GDB in the traditional command-line mode
482 running in an embedded terminal emulator widget, and create a
483 separate MI interpreter running on a specified i/o device. In this
484 way, GDB handles line editing, history, tab completion, etc. in the
485 console all by itself, and the GUI uses the separate MI interpreter
486 for its own control and synchronization, invisible to the command
489 * The "catch syscall" command catches groups of related syscalls.
491 The "catch syscall" command now supports catching a group of related
492 syscalls using the 'group:' or 'g:' prefix.
497 skip -gfile file-glob-pattern
498 skip -function function
499 skip -rfunction regular-expression
500 A generalized form of the skip command, with new support for
501 glob-style file names and regular expressions for function names.
502 Additionally, a file spec and a function spec may now be combined.
504 maint info line-table REGEXP
505 Display the contents of GDB's internal line table data struture.
508 Run any GDB unit tests that were compiled in.
511 Start a new user interface instance running INTERP as interpreter,
512 using the TTY file for input/output.
516 ** gdb.Breakpoint objects have a new attribute "pending", which
517 indicates whether the breakpoint is pending.
518 ** Three new breakpoint-related events have been added:
519 gdb.breakpoint_created, gdb.breakpoint_modified, and
520 gdb.breakpoint_deleted.
523 Signal ("set") the given MS-Windows event object. This is used in
524 conjunction with the Windows JIT debugging (AeDebug) support, where
525 the OS suspends a crashing process until a debugger can attach to
526 it. Resuming the crashing process, in order to debug it, is done by
529 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
530 was added in GDBserver, including JIT compiling fast tracepoint's
531 conditional expression bytecode into native code.
533 * Support for various remote target protocols and ROM monitors has
536 target m32rsdi Remote M32R debugging over SDI
537 target mips MIPS remote debugging protocol
538 target pmon PMON ROM monitor
539 target ddb NEC's DDB variant of PMON for Vr4300
540 target rockhopper NEC RockHopper variant of PMON
541 target lsi LSI variant of PMO
543 * Support for tracepoints and fast tracepoints on powerpc-linux,
544 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
545 including JIT compiling fast tracepoint's conditional expression
546 bytecode into native code.
548 * MI async record =record-started now includes the method and format used for
549 recording. For example:
551 =record-started,thread-group="i1",method="btrace",format="bts"
553 * MI async record =thread-selected now includes the frame field. For example:
555 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
559 Andes NDS32 nds32*-*-elf
561 *** Changes in GDB 7.11
563 * GDB now supports debugging kernel-based threads on FreeBSD.
565 * Per-inferior thread numbers
567 Thread numbers are now per inferior instead of global. If you're
568 debugging multiple inferiors, GDB displays thread IDs using a
569 qualified INF_NUM.THR_NUM form. For example:
573 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
574 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
575 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
576 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
578 As consequence, thread numbers as visible in the $_thread
579 convenience variable and in Python's InferiorThread.num attribute
580 are no longer unique between inferiors.
582 GDB now maintains a second thread ID per thread, referred to as the
583 global thread ID, which is the new equivalent of thread numbers in
584 previous releases. See also $_gthread below.
586 For backwards compatibility, MI's thread IDs always refer to global
589 * Commands that accept thread IDs now accept the qualified
590 INF_NUM.THR_NUM form as well. For example:
593 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
596 * In commands that accept a list of thread IDs, you can now refer to
597 all threads of an inferior using a star wildcard. GDB accepts
598 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
599 refer to all threads of the current inferior. For example, "info
602 * You can use "info threads -gid" to display the global thread ID of
605 * The new convenience variable $_gthread holds the global number of
608 * The new convenience variable $_inferior holds the number of the
611 * GDB now displays the ID and name of the thread that hit a breakpoint
612 or received a signal, if your program is multi-threaded. For
615 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
616 Thread 1 "main" received signal SIGINT, Interrupt.
618 * Record btrace now supports non-stop mode.
620 * Support for tracepoints on aarch64-linux was added in GDBserver.
622 * The 'record instruction-history' command now indicates speculative execution
623 when using the Intel Processor Trace recording format.
625 * GDB now allows users to specify explicit locations, bypassing
626 the linespec parser. This feature is also available to GDB/MI
629 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
630 GDB now is able to debug both AArch64 applications and ARM applications
633 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
634 including JIT compiling fast tracepoint's conditional expression bytecode
637 * GDB now supports displaced stepping on AArch64 GNU/Linux.
639 * "info threads", "info inferiors", "info display", "info checkpoints"
640 and "maint info program-spaces" now list the corresponding items in
641 ascending ID order, for consistency with all other "info" commands.
643 * In Ada, the overloads selection menu has been enhanced to display the
644 parameter types and the return types for the matching overloaded subprograms.
648 maint set target-non-stop (on|off|auto)
649 maint show target-non-stop
650 Control whether GDB targets always operate in non-stop mode even if
651 "set non-stop" is "off". The default is "auto", meaning non-stop
652 mode is enabled if supported by the target.
654 maint set bfd-sharing
655 maint show bfd-sharing
656 Control the reuse of bfd objects.
660 Control display of debugging info regarding bfd caching.
664 Control display of debugging info regarding FreeBSD threads.
666 set remote multiprocess-extensions-packet
667 show remote multiprocess-extensions-packet
668 Set/show the use of the remote protocol multiprocess extensions.
670 set remote thread-events
671 show remote thread-events
672 Set/show the use of thread create/exit events.
674 set ada print-signatures on|off
675 show ada print-signatures"
676 Control whether parameter types and return types are displayed in overloads
677 selection menus. It is activaled (@code{on}) by default.
681 Controls the maximum size of memory, in bytes, that GDB will
682 allocate for value contents. Prevents incorrect programs from
683 causing GDB to allocate overly large buffers. Default is 64k.
685 * The "disassemble" command accepts a new modifier: /s.
686 It prints mixed source+disassembly like /m with two differences:
687 - disassembled instructions are now printed in program order, and
688 - and source for all relevant files is now printed.
689 The "/m" option is now considered deprecated: its "source-centric"
690 output hasn't proved useful in practice.
692 * The "record instruction-history" command accepts a new modifier: /s.
693 It behaves exactly like /m and prints mixed source+disassembly.
695 * The "set scheduler-locking" command supports a new mode "replay".
696 It behaves like "off" in record mode and like "on" in replay mode.
698 * Support for various ROM monitors has been removed:
700 target dbug dBUG ROM monitor for Motorola ColdFire
701 target picobug Motorola picobug monitor
702 target dink32 DINK32 ROM monitor for PowerPC
703 target m32r Renesas M32R/D ROM monitor
704 target mon2000 mon2000 ROM monitor
705 target ppcbug PPCBUG ROM monitor for PowerPC
707 * Support for reading/writing memory and extracting values on architectures
708 whose memory is addressable in units of any integral multiple of 8 bits.
711 Allows to break when an Ada exception is handled.
716 Indicates that an exec system call was executed.
718 exec-events feature in qSupported
719 The qSupported packet allows GDB to request support for exec
720 events using the new 'gdbfeature' exec-event, and the qSupported
721 response can contain the corresponding 'stubfeature'. Set and
722 show commands can be used to display whether these features are enabled.
725 Equivalent to interrupting with the ^C character, but works in
728 thread created stop reason (T05 create:...)
729 Indicates that the thread was just created and is stopped at entry.
731 thread exit stop reply (w exitcode;tid)
732 Indicates that the thread has terminated.
735 Enables/disables thread create and exit event reporting. For
736 example, this is used in non-stop mode when GDB stops a set of
737 threads and synchronously waits for the their corresponding stop
738 replies. Without exit events, if one of the threads exits, GDB
739 would hang forever not knowing that it should no longer expect a
740 stop for that same thread.
743 Indicates that there are no resumed threads left in the target (all
744 threads are stopped). The remote stub reports support for this stop
745 reply to GDB's qSupported query.
748 Enables/disables catching syscalls from the inferior process.
749 The remote stub reports support for this packet to GDB's qSupported query.
751 syscall_entry stop reason
752 Indicates that a syscall was just called.
754 syscall_return stop reason
755 Indicates that a syscall just returned.
757 * Extended-remote exec events
759 ** GDB now has support for exec events on extended-remote Linux targets.
760 For such targets with Linux kernels 2.5.46 and later, this enables
761 follow-exec-mode and exec catchpoints.
763 set remote exec-event-feature-packet
764 show remote exec-event-feature-packet
765 Set/show the use of the remote exec event feature.
767 * Thread names in remote protocol
769 The reply to qXfer:threads:read may now include a name attribute for each
772 * Target remote mode fork and exec events
774 ** GDB now has support for fork and exec events on target remote mode
775 Linux targets. For such targets with Linux kernels 2.5.46 and later,
776 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
777 fork and exec catchpoints.
779 * Remote syscall events
781 ** GDB now has support for catch syscall on remote Linux targets,
782 currently enabled on x86/x86_64 architectures.
784 set remote catch-syscall-packet
785 show remote catch-syscall-packet
786 Set/show the use of the remote catch syscall feature.
790 ** The -var-set-format command now accepts the zero-hexadecimal
791 format. It outputs data in hexadecimal format with zero-padding on the
796 ** gdb.InferiorThread objects have a new attribute "global_num",
797 which refers to the thread's global thread ID. The existing
798 "num" attribute now refers to the thread's per-inferior number.
799 See "Per-inferior thread numbers" above.
800 ** gdb.InferiorThread objects have a new attribute "inferior", which
801 is the Inferior object the thread belongs to.
803 *** Changes in GDB 7.10
805 * Support for process record-replay and reverse debugging on aarch64*-linux*
806 targets has been added. GDB now supports recording of A64 instruction set
807 including advance SIMD instructions.
809 * Support for Sun's version of the "stabs" debug file format has been removed.
811 * GDB now honors the content of the file /proc/PID/coredump_filter
812 (PID is the process ID) on GNU/Linux systems. This file can be used
813 to specify the types of memory mappings that will be included in a
814 corefile. For more information, please refer to the manual page of
815 "core(5)". GDB also has a new command: "set use-coredump-filter
816 on|off". It allows to set whether GDB will read the content of the
817 /proc/PID/coredump_filter file when generating a corefile.
819 * The "info os" command on GNU/Linux can now display information on
821 "info os cpus" Listing of all cpus/cores on the system
823 * GDB has two new commands: "set serial parity odd|even|none" and
824 "show serial parity". These allows to set or show parity for the
827 * The "info source" command now displays the producer string if it was
828 present in the debug info. This typically includes the compiler version
829 and may include things like its command line arguments.
831 * The "info dll", an alias of the "info sharedlibrary" command,
832 is now available on all platforms.
834 * Directory names supplied to the "set sysroot" commands may be
835 prefixed with "target:" to tell GDB to access shared libraries from
836 the target system, be it local or remote. This replaces the prefix
837 "remote:". The default sysroot has been changed from "" to
838 "target:". "remote:" is automatically converted to "target:" for
839 backward compatibility.
841 * The system root specified by "set sysroot" will be prepended to the
842 filename of the main executable (if reported to GDB as absolute by
843 the operating system) when starting processes remotely, and when
844 attaching to already-running local or remote processes.
846 * GDB now supports automatic location and retrieval of executable
847 files from remote targets. Remote debugging can now be initiated
848 using only a "target remote" or "target extended-remote" command
849 (no "set sysroot" or "file" commands are required). See "New remote
852 * The "dump" command now supports verilog hex format.
854 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
856 * On GNU/Linux, GDB and gdbserver are now able to access executable
857 and shared library files without a "set sysroot" command when
858 attaching to processes running in different mount namespaces from
859 the debugger. This makes it possible to attach to processes in
860 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
861 See "New remote packets" below.
863 * The "tui reg" command now provides completion for all of the
864 available register groups, including target specific groups.
866 * The HISTSIZE environment variable is no longer read when determining
867 the size of GDB's command history. GDB now instead reads the dedicated
868 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
869 disables truncation of command history. Non-numeric values of GDBHISTSIZE
874 ** Memory ports can now be unbuffered.
878 ** gdb.Objfile objects have a new attribute "username",
879 which is the name of the objfile as specified by the user,
880 without, for example, resolving symlinks.
881 ** You can now write frame unwinders in Python.
882 ** gdb.Type objects have a new method "optimized_out",
883 returning optimized out gdb.Value instance of this type.
884 ** gdb.Value objects have new methods "reference_value" and
885 "const_value" which return a reference to the value and a
886 "const" version of the value respectively.
890 maint print symbol-cache
891 Print the contents of the symbol cache.
893 maint print symbol-cache-statistics
894 Print statistics of symbol cache usage.
896 maint flush-symbol-cache
897 Flush the contents of the symbol cache.
901 Start branch trace recording using Branch Trace Store (BTS) format.
904 Evaluate expression by using the compiler and print result.
908 Explicit commands for enabling and disabling tui mode.
911 set mpx bound on i386 and amd64
912 Support for bound table investigation on Intel MPX enabled applications.
916 Start branch trace recording using Intel Processor Trace format.
919 Print information about branch tracing internals.
921 maint btrace packet-history
922 Print the raw branch tracing data.
924 maint btrace clear-packet-history
925 Discard the stored raw branch tracing data.
928 Discard all branch tracing data. It will be fetched and processed
929 anew by the next "record" command.
934 Renamed from "set debug dwarf2-die".
936 Renamed from "show debug dwarf2-die".
939 Renamed from "set debug dwarf2-read".
940 show debug dwarf-read
941 Renamed from "show debug dwarf2-read".
943 maint set dwarf always-disassemble
944 Renamed from "maint set dwarf2 always-disassemble".
945 maint show dwarf always-disassemble
946 Renamed from "maint show dwarf2 always-disassemble".
948 maint set dwarf max-cache-age
949 Renamed from "maint set dwarf2 max-cache-age".
950 maint show dwarf max-cache-age
951 Renamed from "maint show dwarf2 max-cache-age".
954 show debug dwarf-line
955 Control display of debugging info regarding DWARF line processing.
959 Set the maximum number of candidates to be considered during
960 completion. The default value is 200. This limit allows GDB
961 to avoid generating large completion lists, the computation of
962 which can cause the debugger to become temporarily unresponsive.
964 set history remove-duplicates
965 show history remove-duplicates
966 Control the removal of duplicate history entries.
968 maint set symbol-cache-size
969 maint show symbol-cache-size
970 Control the size of the symbol cache.
972 set|show record btrace bts buffer-size
973 Set and show the size of the ring buffer used for branch tracing in
975 The obtained size may differ from the requested size. Use "info
976 record" to see the obtained buffer size.
978 set debug linux-namespaces
979 show debug linux-namespaces
980 Control display of debugging info regarding Linux namespaces.
982 set|show record btrace pt buffer-size
983 Set and show the size of the ring buffer used for branch tracing in
984 Intel Processor Trace format.
985 The obtained size may differ from the requested size. Use "info
986 record" to see the obtained buffer size.
988 maint set|show btrace pt skip-pad
989 Set and show whether PAD packets are skipped when computing the
992 * The command 'thread apply all' can now support new option '-ascending'
993 to call its specified command for all threads in ascending order.
995 * Python/Guile scripting
997 ** GDB now supports auto-loading of Python/Guile scripts contained in the
998 special section named `.debug_gdb_scripts'.
1000 * New remote packets
1002 qXfer:btrace-conf:read
1003 Return the branch trace configuration for the current thread.
1005 Qbtrace-conf:bts:size
1006 Set the requested ring buffer size for branch tracing in BTS format.
1009 Enable Intel Procesor Trace-based branch tracing for the current
1010 process. The remote stub reports support for this packet to GDB's
1013 Qbtrace-conf:pt:size
1014 Set the requested ring buffer size for branch tracing in Intel Processor
1018 Indicates a memory breakpoint instruction was executed, irrespective
1019 of whether it was GDB that planted the breakpoint or the breakpoint
1020 is hardcoded in the program. This is required for correct non-stop
1024 Indicates the target stopped for a hardware breakpoint. This is
1025 required for correct non-stop mode operation.
1028 Return information about files on the remote system.
1030 qXfer:exec-file:read
1031 Return the full absolute name of the file that was executed to
1032 create a process running on the remote system.
1035 Select the filesystem on which vFile: operations with filename
1036 arguments will operate. This is required for GDB to be able to
1037 access files on remote targets where the remote stub does not
1038 share a common filesystem with the inferior(s).
1041 Indicates that a fork system call was executed.
1044 Indicates that a vfork system call was executed.
1046 vforkdone stop reason
1047 Indicates that a vfork child of the specified process has executed
1048 an exec or exit, allowing the vfork parent to resume execution.
1050 fork-events and vfork-events features in qSupported
1051 The qSupported packet allows GDB to request support for fork and
1052 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1053 and the qSupported response can contain the corresponding
1054 'stubfeatures'. Set and show commands can be used to display
1055 whether these features are enabled.
1057 * Extended-remote fork events
1059 ** GDB now has support for fork events on extended-remote Linux
1060 targets. For targets with Linux kernels 2.5.60 and later, this
1061 enables follow-fork-mode and detach-on-fork for both fork and
1062 vfork, as well as fork and vfork catchpoints.
1064 * The info record command now shows the recording format and the
1065 branch tracing configuration for the current thread when using
1066 the btrace record target.
1067 For the BTS format, it shows the ring buffer size.
1069 * GDB now has support for DTrace USDT (Userland Static Defined
1070 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1072 * GDB now supports access to vector registers on S/390 GNU/Linux
1075 * Removed command line options
1077 -xdb HP-UX XDB compatibility mode.
1079 * Removed targets and native configurations
1081 HP/PA running HP-UX hppa*-*-hpux*
1082 Itanium running HP-UX ia64-*-hpux*
1084 * New configure options
1087 This configure option allows the user to build GDB with support for
1088 Intel Processor Trace (default: auto). This requires libipt.
1090 --with-libipt-prefix=PATH
1091 Specify the path to the version of libipt that GDB should use.
1092 $PATH/include should contain the intel-pt.h header and
1093 $PATH/lib should contain the libipt.so library.
1095 *** Changes in GDB 7.9.1
1099 ** Xmethods can now specify a result type.
1101 *** Changes in GDB 7.9
1103 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1107 ** You can now access frame registers from Python scripts.
1108 ** New attribute 'producer' for gdb.Symtab objects.
1109 ** gdb.Objfile objects have a new attribute "progspace",
1110 which is the gdb.Progspace object of the containing program space.
1111 ** gdb.Objfile objects have a new attribute "owner".
1112 ** gdb.Objfile objects have a new attribute "build_id",
1113 which is the build ID generated when the file was built.
1114 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1115 ** A new event "gdb.clear_objfiles" has been added, triggered when
1116 selecting a new file to debug.
1117 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1118 ** New function gdb.lookup_objfile.
1120 New events which are triggered when GDB modifies the state of the
1123 ** gdb.events.inferior_call_pre: Function call is about to be made.
1124 ** gdb.events.inferior_call_post: Function call has just been made.
1125 ** gdb.events.memory_changed: A memory location has been altered.
1126 ** gdb.events.register_changed: A register has been altered.
1128 * New Python-based convenience functions:
1130 ** $_caller_is(name [, number_of_frames])
1131 ** $_caller_matches(regexp [, number_of_frames])
1132 ** $_any_caller_is(name [, number_of_frames])
1133 ** $_any_caller_matches(regexp [, number_of_frames])
1135 * GDB now supports the compilation and injection of source code into
1136 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1137 to compile the source code to object code, and if successful, inject
1138 and execute that code within the current context of the inferior.
1139 Currently the C language is supported. The commands used to
1140 interface with this new feature are:
1142 compile code [-raw|-r] [--] [source code]
1143 compile file [-raw|-r] filename
1147 demangle [-l language] [--] name
1148 Demangle "name" in the specified language, or the current language
1149 if elided. This command is renamed from the "maint demangle" command.
1150 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1151 as "maint demangler-warning".
1153 queue-signal signal-name-or-number
1154 Queue a signal to be delivered to the thread when it is resumed.
1156 add-auto-load-scripts-directory directory
1157 Add entries to the list of directories from which to load auto-loaded
1160 maint print user-registers
1161 List all currently available "user" registers.
1163 compile code [-r|-raw] [--] [source code]
1164 Compile, inject, and execute in the inferior the executable object
1165 code produced by compiling the provided source code.
1167 compile file [-r|-raw] filename
1168 Compile and inject into the inferior the executable object code
1169 produced by compiling the source code stored in the filename
1172 * On resume, GDB now always passes the signal the program had stopped
1173 for to the thread the signal was sent to, even if the user changed
1174 threads before resuming. Previously GDB would often (but not
1175 always) deliver the signal to the thread that happens to be current
1178 * Conversely, the "signal" command now consistently delivers the
1179 requested signal to the current thread. GDB now asks for
1180 confirmation if the program had stopped for a signal and the user
1181 switched threads meanwhile.
1183 * "breakpoint always-inserted" modes "off" and "auto" merged.
1185 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1186 won't remove breakpoints from the target until all threads stop,
1187 even in non-stop mode. The "auto" mode has been removed, and "off"
1188 is now the default mode.
1192 set debug symbol-lookup
1193 show debug symbol-lookup
1194 Control display of debugging info regarding symbol lookup.
1198 ** The -list-thread-groups command outputs an exit-code field for
1199 inferiors that have exited.
1203 MIPS SDE mips*-sde*-elf*
1207 Support for these obsolete configurations has been removed.
1209 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1210 SGI Irix-5.x mips-*-irix5*
1211 SGI Irix-6.x mips-*-irix6*
1212 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1213 VAX running Ultrix vax-*-ultrix*
1215 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1216 and "assf"), have been removed. Use the "sharedlibrary" command, or
1217 its alias "share", instead.
1219 *** Changes in GDB 7.8
1221 * New command line options
1224 This is an alias for the --data-directory option.
1226 * GDB supports printing and modifying of variable length automatic arrays
1227 as specified in ISO C99.
1229 * The ARM simulator now supports instruction level tracing
1230 with or without disassembly.
1234 GDB now has support for scripting using Guile. Whether this is
1235 available is determined at configure time.
1236 Guile version 2.0 or greater is required.
1237 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1239 * New commands (for set/show, see "New options" below)
1243 Invoke CODE by passing it to the Guile interpreter.
1247 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1249 info auto-load guile-scripts [regexp]
1250 Print the list of automatically loaded Guile scripts.
1252 * The source command is now capable of sourcing Guile scripts.
1253 This feature is dependent on the debugger being built with Guile support.
1257 set print symbol-loading (off|brief|full)
1258 show print symbol-loading
1259 Control whether to print informational messages when loading symbol
1260 information for a file. The default is "full", but when debugging
1261 programs with large numbers of shared libraries the amount of output
1262 becomes less useful.
1264 set guile print-stack (none|message|full)
1265 show guile print-stack
1266 Show a stack trace when an error is encountered in a Guile script.
1268 set auto-load guile-scripts (on|off)
1269 show auto-load guile-scripts
1270 Control auto-loading of Guile script files.
1272 maint ada set ignore-descriptive-types (on|off)
1273 maint ada show ignore-descriptive-types
1274 Control whether the debugger should ignore descriptive types in Ada
1275 programs. The default is not to ignore the descriptive types. See
1276 the user manual for more details on descriptive types and the intended
1277 usage of this option.
1279 set auto-connect-native-target
1281 Control whether GDB is allowed to automatically connect to the
1282 native target for the run, attach, etc. commands when not connected
1283 to any target yet. See also "target native" below.
1285 set record btrace replay-memory-access (read-only|read-write)
1286 show record btrace replay-memory-access
1287 Control what memory accesses are allowed during replay.
1289 maint set target-async (on|off)
1290 maint show target-async
1291 This controls whether GDB targets operate in synchronous or
1292 asynchronous mode. Normally the default is asynchronous, if it is
1293 available; but this can be changed to more easily debug problems
1294 occurring only in synchronous mode.
1296 set mi-async (on|off)
1298 Control whether MI asynchronous mode is preferred. This supersedes
1299 "set target-async" of previous GDB versions.
1301 * "set target-async" is deprecated as a CLI option and is now an alias
1302 for "set mi-async" (only puts MI into async mode).
1304 * Background execution commands (e.g., "c&", "s&", etc.) are now
1305 possible ``out of the box'' if the target supports them. Previously
1306 the user would need to explicitly enable the possibility with the
1307 "set target-async on" command.
1309 * New features in the GDB remote stub, GDBserver
1311 ** New option --debug-format=option1[,option2,...] allows one to add
1312 additional text to each output. At present only timestamps
1313 are supported: --debug-format=timestamps.
1314 Timestamps can also be turned on with the
1315 "monitor set debug-format timestamps" command from GDB.
1317 * The 'record instruction-history' command now starts counting instructions
1318 at one. This also affects the instruction ranges reported by the
1319 'record function-call-history' command when given the /i modifier.
1321 * The command 'record function-call-history' supports a new modifier '/c' to
1322 indent the function names based on their call stack depth.
1323 The fields for the '/i' and '/l' modifier have been reordered.
1324 The source line range is now prefixed with 'at'.
1325 The instruction range is now prefixed with 'inst'.
1326 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1327 "record instruction-history" and "list" commands.
1329 * The ranges given as arguments to the 'record function-call-history' and
1330 'record instruction-history' commands are now inclusive.
1332 * The btrace record target now supports the 'record goto' command.
1333 For locations inside the execution trace, the back trace is computed
1334 based on the information stored in the execution trace.
1336 * The btrace record target supports limited reverse execution and replay.
1337 The target does not record data and therefore does not allow reading
1338 memory or registers.
1340 * The "catch syscall" command now works on s390*-linux* targets.
1342 * The "compare-sections" command is no longer specific to target
1343 remote. It now works with all targets.
1345 * All native targets are now consistently called "native".
1346 Consequently, the "target child", "target GNU", "target djgpp",
1347 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1348 commands have been replaced with "target native". The QNX/NTO port
1349 leaves the "procfs" target in place and adds a "native" target for
1350 consistency with other ports. The impact on users should be minimal
1351 as these commands previously either throwed an error, or were
1352 no-ops. The target's name is visible in the output of the following
1353 commands: "help target", "info target", "info files", "maint print
1356 * The "target native" command now connects to the native target. This
1357 can be used to launch native programs even when "set
1358 auto-connect-native-target" is set to off.
1360 * GDB now supports access to Intel MPX registers on GNU/Linux.
1362 * Support for Intel AVX-512 registers on GNU/Linux.
1363 Support displaying and modifying Intel AVX-512 registers
1364 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1366 * New remote packets
1368 qXfer:btrace:read's annex
1369 The qXfer:btrace:read packet supports a new annex 'delta' to read
1370 branch trace incrementally.
1374 ** Valid Python operations on gdb.Value objects representing
1375 structs/classes invoke the corresponding overloaded operators if
1377 ** New `Xmethods' feature in the Python API. Xmethods are
1378 additional methods or replacements for existing methods of a C++
1379 class. This feature is useful for those cases where a method
1380 defined in C++ source code could be inlined or optimized out by
1381 the compiler, making it unavailable to GDB.
1384 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1386 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1387 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1388 its alias "share", instead.
1390 * The commands "set remotebaud" and "show remotebaud" are no longer
1391 supported. Use "set serial baud" and "show serial baud" (respectively)
1396 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1397 target-async". The latter is left as a deprecated alias of the
1398 former for backward compatibility. If the target supports it,
1399 CLI background execution commands are now always possible by
1400 default, independently of whether the frontend stated a
1401 preference for asynchronous execution with "-gdb-set mi-async".
1402 Previously "-gdb-set target-async off" affected both MI execution
1403 commands and CLI execution commands.
1405 *** Changes in GDB 7.7
1407 * Improved support for process record-replay and reverse debugging on
1408 arm*-linux* targets. Support for thumb32 and syscall instruction
1409 recording has been added.
1411 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1413 * GDB now supports Fission DWP file format version 2.
1414 http://gcc.gnu.org/wiki/DebugFission
1416 * New convenience function "$_isvoid", to check whether an expression
1417 is void. A void expression is an expression where the type of the
1418 result is "void". For example, some convenience variables may be
1419 "void" when evaluated (e.g., "$_exitcode" before the execution of
1420 the program being debugged; or an undefined convenience variable).
1421 Another example, when calling a function whose return type is
1424 * The "maintenance print objfiles" command now takes an optional regexp.
1426 * The "catch syscall" command now works on arm*-linux* targets.
1428 * GDB now consistently shows "<not saved>" when printing values of
1429 registers the debug info indicates have not been saved in the frame
1430 and there's nowhere to retrieve them from
1431 (callee-saved/call-clobbered registers):
1436 (gdb) info registers rax
1439 Before, the former would print "<optimized out>", and the latter
1440 "*value not available*".
1442 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1447 ** Frame filters and frame decorators have been added.
1448 ** Temporary breakpoints are now supported.
1449 ** Line tables representation has been added.
1450 ** New attribute 'parent_type' for gdb.Field objects.
1451 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1452 ** New attribute 'name' for gdb.Type objects.
1456 Nios II ELF nios2*-*-elf
1457 Nios II GNU/Linux nios2*-*-linux
1458 Texas Instruments MSP430 msp430*-*-elf
1460 * Removed native configurations
1462 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1463 been removed. ELF variants of these configurations are kept supported.
1465 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1466 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1467 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1468 i[34567]86-*-openbsd3.[0-3]
1469 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1470 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1471 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1475 Like "catch throw", but catches a re-thrown exception.
1476 maint check-psymtabs
1477 Renamed from old "maint check-symtabs".
1479 Perform consistency checks on symtabs.
1480 maint expand-symtabs
1481 Expand symtabs matching an optional regexp.
1484 Display the details of GDB configure-time options.
1486 maint set|show per-command
1487 maint set|show per-command space
1488 maint set|show per-command time
1489 maint set|show per-command symtab
1490 Enable display of per-command gdb resource usage.
1492 remove-symbol-file FILENAME
1493 remove-symbol-file -a ADDRESS
1494 Remove a symbol file added via add-symbol-file. The file to remove
1495 can be identified by its filename or by an address that lies within
1496 the boundaries of this symbol file in memory.
1499 info exceptions REGEXP
1500 Display the list of Ada exceptions defined in the program being
1501 debugged. If provided, only the exceptions whose names match REGEXP
1506 set debug symfile off|on
1508 Control display of debugging info regarding reading symbol files and
1509 symbol tables within those files
1511 set print raw frame-arguments
1512 show print raw frame-arguments
1513 Set/show whether to print frame arguments in raw mode,
1514 disregarding any defined pretty-printers.
1516 set remote trace-status-packet
1517 show remote trace-status-packet
1518 Set/show the use of remote protocol qTStatus packet.
1522 Control display of debugging messages related to Nios II targets.
1526 Control whether target-assisted range stepping is enabled.
1528 set startup-with-shell
1529 show startup-with-shell
1530 Specifies whether Unix child processes are started via a shell or
1535 Use the target memory cache for accesses to the code segment. This
1536 improves performance of remote debugging (particularly disassembly).
1538 * You can now use a literal value 'unlimited' for options that
1539 interpret 0 or -1 as meaning "unlimited". E.g., "set
1540 trace-buffer-size unlimited" is now an alias for "set
1541 trace-buffer-size -1" and "set height unlimited" is now an alias for
1544 * The "set debug symtab-create" debugging option of GDB has been changed to
1545 accept a verbosity level. 0 means "off", 1 provides basic debugging
1546 output, and values of 2 or greater provides more verbose output.
1548 * New command-line options
1550 Display the details of GDB configure-time options.
1552 * The command 'tsave' can now support new option '-ctf' to save trace
1553 buffer in Common Trace Format.
1555 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1558 * GDB now implements the the C++ 'typeid' operator.
1560 * The new convenience variable $_exception holds the exception being
1561 thrown or caught at an exception-related catchpoint.
1563 * The exception-related catchpoints, like "catch throw", now accept a
1564 regular expression which can be used to filter exceptions by type.
1566 * The new convenience variable $_exitsignal is automatically set to
1567 the terminating signal number when the program being debugged dies
1568 due to an uncaught signal.
1572 ** All MI commands now accept an optional "--language" option.
1573 Support for this feature can be verified by using the "-list-features"
1574 command, which should contain "language-option".
1576 ** The new command -info-gdb-mi-command allows the user to determine
1577 whether a GDB/MI command is supported or not.
1579 ** The "^error" result record returned when trying to execute an undefined
1580 GDB/MI command now provides a variable named "code" whose content is the
1581 "undefined-command" error code. Support for this feature can be verified
1582 by using the "-list-features" command, which should contain
1583 "undefined-command-error-code".
1585 ** The -trace-save MI command can optionally save trace buffer in Common
1588 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1590 ** The command -data-list-register-values now accepts an optional
1591 "--skip-unavailable" option. When used, only the available registers
1594 ** The new command -trace-frame-collected dumps collected variables,
1595 computed expressions, tvars, memory and registers in a traceframe.
1597 ** The commands -stack-list-locals, -stack-list-arguments and
1598 -stack-list-variables now accept an option "--skip-unavailable".
1599 When used, only the available locals or arguments are displayed.
1601 ** The -exec-run command now accepts an optional "--start" option.
1602 When used, the command follows the same semantics as the "start"
1603 command, stopping the program's execution at the start of its
1604 main subprogram. Support for this feature can be verified using
1605 the "-list-features" command, which should contain
1606 "exec-run-start-option".
1608 ** The new commands -catch-assert and -catch-exceptions insert
1609 catchpoints stopping the program when Ada exceptions are raised.
1611 ** The new command -info-ada-exceptions provides the equivalent of
1612 the new "info exceptions" command.
1614 * New system-wide configuration scripts
1615 A GDB installation now provides scripts suitable for use as system-wide
1616 configuration scripts for the following systems:
1620 * GDB now supports target-assigned range stepping with remote targets.
1621 This improves the performance of stepping source lines by reducing
1622 the number of control packets from/to GDB. See "New remote packets"
1625 * GDB now understands the element 'tvar' in the XML traceframe info.
1626 It has the id of the collected trace state variables.
1628 * On S/390 targets that provide the transactional-execution feature,
1629 the program interruption transaction diagnostic block (TDB) is now
1630 represented as a number of additional "registers" in GDB.
1632 * New remote packets
1636 The vCont packet supports a new 'r' action, that tells the remote
1637 stub to step through an address range itself, without GDB
1638 involvemement at each single-step.
1640 qXfer:libraries-svr4:read's annex
1641 The previously unused annex of the qXfer:libraries-svr4:read packet
1642 is now used to support passing an argument list. The remote stub
1643 reports support for this argument list to GDB's qSupported query.
1644 The defined arguments are "start" and "prev", used to reduce work
1645 necessary for library list updating, resulting in significant
1648 * New features in the GDB remote stub, GDBserver
1650 ** GDBserver now supports target-assisted range stepping. Currently
1651 enabled on x86/x86_64 GNU/Linux targets.
1653 ** GDBserver now adds element 'tvar' in the XML in the reply to
1654 'qXfer:traceframe-info:read'. It has the id of the collected
1655 trace state variables.
1657 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1660 * New 'z' formatter for printing and examining memory, this displays the
1661 value as hexadecimal zero padded on the left to the size of the type.
1663 * GDB can now use Windows x64 unwinding data.
1665 * The "set remotebaud" command has been replaced by "set serial baud".
1666 Similarly, "show remotebaud" has been replaced by "show serial baud".
1667 The "set remotebaud" and "show remotebaud" commands are still available
1668 to provide backward compatibility with older versions of GDB.
1670 *** Changes in GDB 7.6
1672 * Target record has been renamed to record-full.
1673 Record/replay is now enabled with the "record full" command.
1674 This also affects settings that are associated with full record/replay
1675 that have been moved from "set/show record" to "set/show record full":
1677 set|show record full insn-number-max
1678 set|show record full stop-at-limit
1679 set|show record full memory-query
1681 * A new record target "record-btrace" has been added. The new target
1682 uses hardware support to record the control-flow of a process. It
1683 does not support replaying the execution, but it implements the
1684 below new commands for investigating the recorded execution log.
1685 This new recording method can be enabled using:
1689 The "record-btrace" target is only available on Intel Atom processors
1690 and requires a Linux kernel 2.6.32 or later.
1692 * Two new commands have been added for record/replay to give information
1693 about the recorded execution without having to replay the execution.
1694 The commands are only supported by "record btrace".
1696 record instruction-history prints the execution history at
1697 instruction granularity
1699 record function-call-history prints the execution history at
1700 function granularity
1702 * New native configurations
1704 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1705 FreeBSD/powerpc powerpc*-*-freebsd
1706 x86_64/Cygwin x86_64-*-cygwin*
1707 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1711 ARM AArch64 aarch64*-*-elf
1712 ARM AArch64 GNU/Linux aarch64*-*-linux
1713 Lynx 178 PowerPC powerpc-*-lynx*178
1714 x86_64/Cygwin x86_64-*-cygwin*
1715 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1717 * If the configured location of system.gdbinit file (as given by the
1718 --with-system-gdbinit option at configure time) is in the
1719 data-directory (as specified by --with-gdb-datadir at configure
1720 time) or in one of its subdirectories, then GDB will look for the
1721 system-wide init file in the directory specified by the
1722 --data-directory command-line option.
1724 * New command line options:
1726 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1727 other initialization files, unlike -nx which disables all of them.
1729 * Removed command line options
1731 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1734 * The 'ptype' and 'whatis' commands now accept an argument to control
1737 * 'info proc' now works on some core files.
1741 ** Vectors can be created with gdb.Type.vector.
1743 ** Python's atexit.register now works in GDB.
1745 ** Types can be pretty-printed via a Python API.
1747 ** Python 3 is now supported (in addition to Python 2.4 or later)
1749 ** New class gdb.Architecture exposes GDB's internal representation
1750 of architecture in the Python API.
1752 ** New method Frame.architecture returns the gdb.Architecture object
1753 corresponding to the frame's architecture.
1755 * New Python-based convenience functions:
1757 ** $_memeq(buf1, buf2, length)
1758 ** $_streq(str1, str2)
1760 ** $_regex(str, regex)
1762 * The 'cd' command now defaults to using '~' (the home directory) if not
1765 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1766 default for GCC since November 2000.
1768 * The command 'forward-search' can now be abbreviated as 'fo'.
1770 * The command 'info tracepoints' can now display 'installed on target'
1771 or 'not installed on target' for each non-pending location of tracepoint.
1773 * New configure options
1775 --enable-libmcheck/--disable-libmcheck
1776 By default, development versions are built with -lmcheck on hosts
1777 that support it, in order to help track memory corruption issues.
1778 Release versions, on the other hand, are built without -lmcheck
1779 by default. The --enable-libmcheck/--disable-libmcheck configure
1780 options allow the user to override that default.
1781 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1782 This configure option allows the user to build GDB with
1783 libbabeltrace using which GDB can read Common Trace Format data.
1785 * New commands (for set/show, see "New options" below)
1788 Catch signals. This is similar to "handle", but allows commands and
1789 conditions to be attached.
1792 List the BFDs known to GDB.
1794 python-interactive [command]
1796 Start a Python interactive prompt, or evaluate the optional command
1797 and print the result of expressions.
1800 "py" is a new alias for "python".
1802 enable type-printer [name]...
1803 disable type-printer [name]...
1804 Enable or disable type printers.
1808 ** For the Renesas Super-H architecture, the "regs" command has been removed
1809 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1814 set print type methods (on|off)
1815 show print type methods
1816 Control whether method declarations are displayed by "ptype".
1817 The default is to show them.
1819 set print type typedefs (on|off)
1820 show print type typedefs
1821 Control whether typedef definitions are displayed by "ptype".
1822 The default is to show them.
1824 set filename-display basename|relative|absolute
1825 show filename-display
1826 Control the way in which filenames is displayed.
1827 The default is "relative", which preserves previous behavior.
1829 set trace-buffer-size
1830 show trace-buffer-size
1831 Request target to change the size of trace buffer.
1833 set remote trace-buffer-size-packet auto|on|off
1834 show remote trace-buffer-size-packet
1835 Control the use of the remote protocol `QTBuffer:size' packet.
1839 Control display of debugging messages related to ARM AArch64.
1842 set debug coff-pe-read
1843 show debug coff-pe-read
1844 Control display of debugging messages related to reading of COFF/PE
1849 Control display of debugging messages related to Mach-O symbols
1852 set debug notification
1853 show debug notification
1854 Control display of debugging info for async remote notification.
1858 ** Command parameter changes are now notified using new async record
1859 "=cmd-param-changed".
1860 ** Trace frame changes caused by command "tfind" are now notified using
1861 new async record "=traceframe-changed".
1862 ** The creation, deletion and modification of trace state variables
1863 are now notified using new async records "=tsv-created",
1864 "=tsv-deleted" and "=tsv-modified".
1865 ** The start and stop of process record are now notified using new
1866 async record "=record-started" and "=record-stopped".
1867 ** Memory changes are now notified using new async record
1869 ** The data-disassemble command response will include a "fullname" field
1870 containing the absolute file name when source has been requested.
1871 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1872 command, to allow pattern filling of memory areas.
1873 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1874 library load/unload events.
1875 ** The response to breakpoint commands and breakpoint async records
1876 includes an "installed" field containing a boolean state about each
1877 non-pending tracepoint location is whether installed on target or not.
1878 ** Output of the "-trace-status" command includes a "trace-file" field
1879 containing the name of the trace file being examined. This field is
1880 optional, and only present when examining a trace file.
1881 ** The "fullname" field is now always present along with the "file" field,
1882 even if the file cannot be found by GDB.
1884 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1885 You must have the LZMA library available when configuring GDB for this
1886 feature to be enabled. For more information, see:
1887 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1889 * New remote packets
1892 Set the size of trace buffer. The remote stub reports support for this
1893 packet to gdb's qSupported query.
1896 Enable Branch Trace Store (BTS)-based branch tracing for the current
1897 thread. The remote stub reports support for this packet to gdb's
1901 Disable branch tracing for the current thread. The remote stub reports
1902 support for this packet to gdb's qSupported query.
1905 Read the traced branches for the current thread. The remote stub
1906 reports support for this packet to gdb's qSupported query.
1908 *** Changes in GDB 7.5
1910 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1911 for more x32 ABI info.
1913 * GDB now supports access to MIPS DSP registers on Linux targets.
1915 * GDB now supports debugging microMIPS binaries.
1917 * The "info os" command on GNU/Linux can now display information on
1918 several new classes of objects managed by the operating system:
1919 "info os procgroups" lists process groups
1920 "info os files" lists file descriptors
1921 "info os sockets" lists internet-domain sockets
1922 "info os shm" lists shared-memory regions
1923 "info os semaphores" lists semaphores
1924 "info os msg" lists message queues
1925 "info os modules" lists loaded kernel modules
1927 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1928 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1929 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1930 options and inspect the probe arguments using the new $_probe_arg family
1931 of convenience variables. You can obtain more information about SystemTap
1932 in <http://sourceware.org/systemtap/>.
1934 * GDB now supports reversible debugging on ARM, it allows you to
1935 debug basic ARM and THUMB instructions, and provides
1936 record/replay support.
1938 * The option "symbol-reloading" has been deleted as it is no longer used.
1942 ** GDB commands implemented in Python can now be put in command class
1945 ** The "maint set python print-stack on|off" is now deleted.
1947 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1948 apply "flag enum"-style pretty-printing to any enum.
1950 ** gdb.lookup_symbol can now work when there is no current frame.
1952 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1953 the source at which the symbol was defined.
1955 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1956 method 'value'. The former indicates whether the symbol needs a
1957 frame in order to compute its value, and the latter computes the
1960 ** A new method 'referenced_value' on gdb.Value objects which can
1961 dereference pointer as well as C++ reference values.
1963 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1964 which return the global and static blocks (as gdb.Block objects),
1965 of the underlying symbol table, respectively.
1967 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1968 object associated with a PC value.
1970 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1971 of the address range occupied by code for the current source line.
1973 * Go language support.
1974 GDB now supports debugging programs written in the Go programming
1977 * GDBserver now supports stdio connections.
1978 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1980 * The binary "gdbtui" can no longer be built or installed.
1981 Use "gdb -tui" instead.
1983 * GDB will now print "flag" enums specially. A flag enum is one where
1984 all the enumerator values have no bits in common when pairwise
1985 "and"ed. When printing a value whose type is a flag enum, GDB will
1986 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1987 (gdb) print (enum E) 3
1990 * The filename part of a linespec will now match trailing components
1991 of a source file name. For example, "break gcc/expr.c:1000" will
1992 now set a breakpoint in build/gcc/expr.c, but not
1993 build/libcpp/expr.c.
1995 * The "info proc" and "generate-core-file" commands will now also
1996 work on remote targets connected to GDBserver on Linux.
1998 * The command "info catch" has been removed. It has been disabled
1999 since December 2007.
2001 * The "catch exception" and "catch assert" commands now accept
2002 a condition at the end of the command, much like the "break"
2003 command does. For instance:
2005 (gdb) catch exception Constraint_Error if Barrier = True
2007 Previously, it was possible to add a condition to such catchpoints,
2008 but it had to be done as a second step, after the catchpoint had been
2009 created, using the "condition" command.
2011 * The "info static-tracepoint-marker" command will now also work on
2012 native Linux targets with in-process agent.
2014 * GDB can now set breakpoints on inlined functions.
2016 * The .gdb_index section has been updated to include symbols for
2017 inlined functions. GDB will ignore older .gdb_index sections by
2018 default, which could cause symbol files to be loaded more slowly
2019 until their .gdb_index sections can be recreated. The new command
2020 "set use-deprecated-index-sections on" will cause GDB to use any older
2021 .gdb_index sections it finds. This will restore performance, but the
2022 ability to set breakpoints on inlined functions will be lost in symbol
2023 files with older .gdb_index sections.
2025 The .gdb_index section has also been updated to record more information
2026 about each symbol. This speeds up the "info variables", "info functions"
2027 and "info types" commands when used with programs having the .gdb_index
2028 section, as well as speeding up debugging with shared libraries using
2029 the .gdb_index section.
2031 * Ada support for GDB/MI Variable Objects has been added.
2033 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2038 ** New command -info-os is the MI equivalent of "info os".
2040 ** Output logs ("set logging" and related) now include MI output.
2044 ** "set use-deprecated-index-sections on|off"
2045 "show use-deprecated-index-sections on|off"
2046 Controls the use of deprecated .gdb_index sections.
2048 ** "catch load" and "catch unload" can be used to stop when a shared
2049 library is loaded or unloaded, respectively.
2051 ** "enable count" can be used to auto-disable a breakpoint after
2054 ** "info vtbl" can be used to show the virtual method tables for
2055 C++ and Java objects.
2057 ** "explore" and its sub commands "explore value" and "explore type"
2058 can be used to recursively explore values and types of
2059 expressions. These commands are available only if GDB is
2060 configured with '--with-python'.
2062 ** "info auto-load" shows status of all kinds of auto-loaded files,
2063 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2064 sequences of commands files, "info auto-load python-scripts"
2065 shows status of auto-loading Python script files,
2066 "info auto-load local-gdbinit" shows status of loading init file
2067 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2068 status of inferior specific thread debugging shared library loading.
2070 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2071 and "show auto-load-scripts" commands have been deprecated, use their
2072 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2073 and "show auto-load python-scripts" counterparts instead.
2075 ** "dprintf location,format,args..." creates a dynamic printf, which
2076 is basically a breakpoint that does a printf and immediately
2077 resumes your program's execution, so it is like a printf that you
2078 can insert dynamically at runtime instead of at compiletime.
2080 ** "set print symbol"
2082 Controls whether GDB attempts to display the symbol, if any,
2083 corresponding to addresses it prints. This defaults to "on", but
2084 you can set it to "off" to restore GDB's previous behavior.
2086 * Deprecated commands
2088 ** For the Renesas Super-H architecture, the "regs" command has been
2089 deprecated, and "info all-registers" should be used instead.
2093 Renesas RL78 rl78-*-elf
2094 HP OpenVMS ia64 ia64-hp-openvms*
2096 * GDBserver supports evaluation of breakpoint conditions. When
2097 support is advertised by GDBserver, GDB may be told to send the
2098 breakpoint conditions in bytecode form to GDBserver. GDBserver
2099 will only report the breakpoint trigger to GDB when its condition
2104 set mips compression
2105 show mips compression
2106 Select the compressed ISA encoding used in functions that have no symbol
2107 information available. The encoding can be set to either of:
2110 and is updated automatically from ELF file flags if available.
2112 set breakpoint condition-evaluation
2113 show breakpoint condition-evaluation
2114 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2115 GDBserver ("target"). Default option "auto" chooses the most efficient
2117 This option can improve debugger efficiency depending on the speed of the
2121 Disable auto-loading globally.
2124 Show auto-loading setting of all kinds of auto-loaded files.
2126 set auto-load gdb-scripts on|off
2127 show auto-load gdb-scripts
2128 Control auto-loading of GDB canned sequences of commands files.
2130 set auto-load python-scripts on|off
2131 show auto-load python-scripts
2132 Control auto-loading of Python script files.
2134 set auto-load local-gdbinit on|off
2135 show auto-load local-gdbinit
2136 Control loading of init file (.gdbinit) from current directory.
2138 set auto-load libthread-db on|off
2139 show auto-load libthread-db
2140 Control auto-loading of inferior specific thread debugging shared library.
2142 set auto-load scripts-directory <dir1>[:<dir2>...]
2143 show auto-load scripts-directory
2144 Set a list of directories from which to load auto-loaded scripts.
2145 Automatically loaded Python scripts and GDB scripts are located in one
2146 of the directories listed by this option.
2147 The delimiter (':' above) may differ according to the host platform.
2149 set auto-load safe-path <dir1>[:<dir2>...]
2150 show auto-load safe-path
2151 Set a list of directories from which it is safe to auto-load files.
2152 The delimiter (':' above) may differ according to the host platform.
2154 set debug auto-load on|off
2155 show debug auto-load
2156 Control display of debugging info for auto-loading the files above.
2158 set dprintf-style gdb|call|agent
2160 Control the way in which a dynamic printf is performed; "gdb"
2161 requests a GDB printf command, while "call" causes dprintf to call a
2162 function in the inferior. "agent" requests that the target agent
2163 (such as GDBserver) do the printing.
2165 set dprintf-function <expr>
2166 show dprintf-function
2167 set dprintf-channel <expr>
2168 show dprintf-channel
2169 Set the function and optional first argument to the call when using
2170 the "call" style of dynamic printf.
2172 set disconnected-dprintf on|off
2173 show disconnected-dprintf
2174 Control whether agent-style dynamic printfs continue to be in effect
2175 after GDB disconnects.
2177 * New configure options
2179 --with-auto-load-dir
2180 Configure default value for the 'set auto-load scripts-directory'
2181 setting above. It defaults to '$debugdir:$datadir/auto-load',
2182 $debugdir representing global debugging info directories (available
2183 via 'show debug-file-directory') and $datadir representing GDB's data
2184 directory (available via 'show data-directory').
2186 --with-auto-load-safe-path
2187 Configure default value for the 'set auto-load safe-path' setting
2188 above. It defaults to the --with-auto-load-dir setting.
2190 --without-auto-load-safe-path
2191 Set 'set auto-load safe-path' to '/', effectively disabling this
2194 * New remote packets
2196 z0/z1 conditional breakpoints extension
2198 The z0/z1 breakpoint insertion packets have been extended to carry
2199 a list of conditional expressions over to the remote stub depending on the
2200 condition evaluation mode. The use of this extension can be controlled
2201 via the "set remote conditional-breakpoints-packet" command.
2205 Specify the signals which the remote stub may pass to the debugged
2206 program without GDB involvement.
2208 * New command line options
2210 --init-command=FILE, -ix Like --command, -x but execute it
2211 before loading inferior.
2212 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2213 execute it before loading inferior.
2215 *** Changes in GDB 7.4
2217 * GDB now handles ambiguous linespecs more consistently; the existing
2218 FILE:LINE support has been expanded to other types of linespecs. A
2219 breakpoint will now be set on all matching locations in all
2220 inferiors, and locations will be added or removed according to
2223 * GDB now allows you to skip uninteresting functions and files when
2224 stepping with the "skip function" and "skip file" commands.
2226 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2227 and "show remote hardware-watchpoint-length-limit". These allows to
2228 set or show the maximum length limit (in bytes) of a remote
2229 target hardware watchpoint.
2231 This allows e.g. to use "unlimited" hardware watchpoints with the
2232 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2233 watchpoints are slower than real hardware watchpoints but are
2234 significantly faster than gdb software watchpoints.
2238 ** The register_pretty_printer function in module gdb.printing now takes
2239 an optional `replace' argument. If True, the new printer replaces any
2242 ** The "maint set python print-stack on|off" command has been
2243 deprecated and will be deleted in GDB 7.5.
2244 A new command: "set python print-stack none|full|message" has
2245 replaced it. Additionally, the default for "print-stack" is
2246 now "message", which just prints the error message without
2249 ** A prompt substitution hook (prompt_hook) is now available to the
2252 ** A new Python module, gdb.prompt has been added to the GDB Python
2253 modules library. This module provides functionality for
2254 escape sequences in prompts (used by set/show
2255 extended-prompt). These escape sequences are replaced by their
2256 corresponding value.
2258 ** Python commands and convenience-functions located in
2259 'data-directory'/python/gdb/command and
2260 'data-directory'/python/gdb/function are now automatically loaded
2263 ** Blocks now provide four new attributes. global_block and
2264 static_block will return the global and static blocks
2265 respectively. is_static and is_global are boolean attributes
2266 that indicate if the block is one of those two types.
2268 ** Symbols now provide the "type" attribute, the type of the symbol.
2270 ** The "gdb.breakpoint" function has been deprecated in favor of
2273 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2274 of a function. This class is based on the "finish" command
2275 available in the CLI.
2277 ** Type objects for struct and union types now allow access to
2278 the fields using standard Python dictionary (mapping) methods.
2279 For example, "some_type['myfield']" now works, as does
2280 "some_type.items()".
2282 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2285 ** A new function, "deep_items" has been added to the gdb.types
2286 module in the GDB Python modules library. This function returns
2287 an iterator over the fields of a struct or union type. Unlike
2288 the standard Python "iteritems" method, it will recursively traverse
2289 any anonymous fields.
2293 ** "*stopped" events can report several new "reason"s, such as
2296 ** Breakpoint changes are now notified using new async records, like
2297 "=breakpoint-modified".
2299 ** New command -ada-task-info.
2301 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2302 $sdir specifies the default system locations of shared libraries.
2303 $pdir specifies the directory where the libpthread used by the application
2306 GDB no longer looks in $sdir and $pdir after it has searched the directories
2307 mentioned in libthread-db-search-path. If you want to search those
2308 directories, they must be specified in libthread-db-search-path.
2309 The default value of libthread-db-search-path on GNU/Linux and Solaris
2310 systems is now "$sdir:$pdir".
2312 $pdir is not supported by gdbserver, it is currently ignored.
2313 $sdir is supported by gdbserver.
2315 * New configure option --with-iconv-bin.
2316 When using the internationalization support like the one in the GNU C
2317 library, GDB will invoke the "iconv" program to get a list of supported
2318 character sets. If this program lives in a non-standard location, one can
2319 use this option to specify where to find it.
2321 * When natively debugging programs on PowerPC BookE processors running
2322 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2323 watchpoints, which specify a mask in addition to an address to watch.
2324 The mask specifies that some bits of an address (the bits which are
2325 reset in the mask) should be ignored when matching the address accessed
2326 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2327 section in the user manual for more details.
2329 * The new option --once causes GDBserver to stop listening for connections once
2330 the first connection is made. The listening port used by GDBserver will
2331 become available after that.
2333 * New commands "info macros" and "alias" have been added.
2335 * New function parameters suffix @entry specifies value of function parameter
2336 at the time the function got called. Entry values are available only since
2342 "!" is now an alias of the "shell" command.
2343 Note that no space is needed between "!" and SHELL COMMAND.
2347 watch EXPRESSION mask MASK_VALUE
2348 The watch command now supports the mask argument which allows creation
2349 of masked watchpoints, if the current architecture supports this feature.
2351 info auto-load-scripts [REGEXP]
2352 This command was formerly named "maintenance print section-scripts".
2353 It is now generally useful and is no longer a maintenance-only command.
2355 info macro [-all] [--] MACRO
2356 The info macro command has new options `-all' and `--'. The first for
2357 printing all definitions of a macro. The second for explicitly specifying
2358 the end of arguments and the beginning of the macro name in case the macro
2359 name starts with a hyphen.
2361 collect[/s] EXPRESSIONS
2362 The tracepoint collect command now takes an optional modifier "/s"
2363 that directs it to dereference pointer-to-character types and
2364 collect the bytes of memory up to a zero byte. The behavior is
2365 similar to what you see when you use the regular print command on a
2366 string. An optional integer following the "/s" sets a bound on the
2367 number of bytes that will be collected.
2370 The trace start command now interprets any supplied arguments as a
2371 note to be recorded with the trace run, with an effect similar to
2372 setting the variable trace-notes.
2375 The trace stop command now interprets any arguments as a note to be
2376 mentioned along with the tstatus report that the trace was stopped
2377 with a command. The effect is similar to setting the variable
2380 * Tracepoints can now be enabled and disabled at any time after a trace
2381 experiment has been started using the standard "enable" and "disable"
2382 commands. It is now possible to start a trace experiment with no enabled
2383 tracepoints; GDB will display a warning, but will allow the experiment to
2384 begin, assuming that tracepoints will be enabled as needed while the trace
2387 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2388 locations with 4-byte instructions, when they were previously
2389 limited to locations with instructions of 5 bytes or longer.
2393 set debug dwarf2-read
2394 show debug dwarf2-read
2395 Turns on or off display of debugging messages related to reading
2396 DWARF debug info. The default is off.
2398 set debug symtab-create
2399 show debug symtab-create
2400 Turns on or off display of debugging messages related to symbol table
2401 creation. The default is off.
2404 show extended-prompt
2405 Set the GDB prompt, and allow escape sequences to be inserted to
2406 display miscellaneous information (see 'help set extended-prompt'
2407 for the list of sequences). This prompt (and any information
2408 accessed through the escape sequences) is updated every time the
2409 prompt is displayed.
2411 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2412 show print entry-values
2413 Set printing of frame argument values at function entry. In some cases
2414 GDB can determine the value of function argument which was passed by the
2415 function caller, even if the value was modified inside the called function.
2417 set debug entry-values
2418 show debug entry-values
2419 Control display of debugging info for determining frame argument values at
2420 function entry and virtual tail call frames.
2422 set basenames-may-differ
2423 show basenames-may-differ
2424 Set whether a source file may have multiple base names.
2425 (A "base name" is the name of a file with the directory part removed.
2426 Example: The base name of "/home/user/hello.c" is "hello.c".)
2427 If set, GDB will canonicalize file names (e.g., expand symlinks)
2428 before comparing them. Canonicalization is an expensive operation,
2429 but it allows the same file be known by more than one base name.
2430 If not set (the default), all source files are assumed to have just
2431 one base name, and gdb will do file name comparisons more efficiently.
2437 Set a user name and notes for the current and any future trace runs.
2438 This is useful for long-running and/or disconnected traces, to
2439 inform others (or yourself) as to who is running the trace, supply
2440 contact information, or otherwise explain what is going on.
2442 set trace-stop-notes
2443 show trace-stop-notes
2444 Set a note attached to the trace run, that is displayed when the
2445 trace has been stopped by a tstop command. This is useful for
2446 instance as an explanation, if you are stopping a trace run that was
2447 started by someone else.
2449 * New remote packets
2453 Dynamically enable a tracepoint in a started trace experiment.
2457 Dynamically disable a tracepoint in a started trace experiment.
2461 Set the user and notes of the trace run.
2465 Query the current status of a tracepoint.
2469 Query the minimum length of instruction at which a fast tracepoint may
2472 * Dcache size (number of lines) and line-size are now runtime-configurable
2473 via "set dcache line" and "set dcache line-size" commands.
2477 Texas Instruments TMS320C6x tic6x-*-*
2481 Renesas RL78 rl78-*-elf
2483 *** Changes in GDB 7.3.1
2485 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2487 *** Changes in GDB 7.3
2489 * GDB has a new command: "thread find [REGEXP]".
2490 It finds the thread id whose name, target id, or thread extra info
2491 matches the given regular expression.
2493 * The "catch syscall" command now works on mips*-linux* targets.
2495 * The -data-disassemble MI command now supports modes 2 and 3 for
2496 dumping the instruction opcodes.
2498 * New command line options
2500 -data-directory DIR Specify DIR as the "data-directory".
2501 This is mostly for testing purposes.
2503 * The "maint set python auto-load on|off" command has been renamed to
2504 "set auto-load-scripts on|off".
2506 * GDB has a new command: "set directories".
2507 It is like the "dir" command except that it replaces the
2508 source path list instead of augmenting it.
2510 * GDB now understands thread names.
2512 On GNU/Linux, "info threads" will display the thread name as set by
2513 prctl or pthread_setname_np.
2515 There is also a new command, "thread name", which can be used to
2516 assign a name internally for GDB to display.
2519 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2520 has been integrated into GDB.
2524 ** The function gdb.Write now accepts an optional keyword 'stream'.
2525 This keyword, when provided, will direct the output to either
2526 stdout, stderr, or GDB's logging output.
2528 ** Parameters can now be be sub-classed in Python, and in particular
2529 you may implement the get_set_doc and get_show_doc functions.
2530 This improves how Parameter set/show documentation is processed
2531 and allows for more dynamic content.
2533 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2534 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2535 have an is_valid method.
2537 ** Breakpoints can now be sub-classed in Python, and in particular
2538 you may implement a 'stop' function that is executed each time
2539 the inferior reaches that breakpoint.
2541 ** New function gdb.lookup_global_symbol looks up a global symbol.
2543 ** GDB values in Python are now callable if the value represents a
2544 function. For example, if 'some_value' represents a function that
2545 takes two integer parameters and returns a value, you can call
2546 that function like so:
2548 result = some_value (10,20)
2550 ** Module gdb.types has been added.
2551 It contains a collection of utilities for working with gdb.Types objects:
2552 get_basic_type, has_field, make_enum_dict.
2554 ** Module gdb.printing has been added.
2555 It contains utilities for writing and registering pretty-printers.
2556 New classes: PrettyPrinter, SubPrettyPrinter,
2557 RegexpCollectionPrettyPrinter.
2558 New function: register_pretty_printer.
2560 ** New commands "info pretty-printers", "enable pretty-printer" and
2561 "disable pretty-printer" have been added.
2563 ** gdb.parameter("directories") is now available.
2565 ** New function gdb.newest_frame returns the newest frame in the
2568 ** The gdb.InferiorThread class has a new "name" attribute. This
2569 holds the thread's name.
2571 ** Python Support for Inferior events.
2572 Python scripts can add observers to be notified of events
2573 occurring in the process being debugged.
2574 The following events are currently supported:
2575 - gdb.events.cont Continue event.
2576 - gdb.events.exited Inferior exited event.
2577 - gdb.events.stop Signal received, and Breakpoint hit events.
2581 ** GDB now puts template parameters in scope when debugging in an
2582 instantiation. For example, if you have:
2584 template<int X> int func (void) { return X; }
2586 then if you step into func<5>, "print X" will show "5". This
2587 feature requires proper debuginfo support from the compiler; it
2588 was added to GCC 4.5.
2590 ** The motion commands "next", "finish", "until", and "advance" now
2591 work better when exceptions are thrown. In particular, GDB will
2592 no longer lose control of the inferior; instead, the GDB will
2593 stop the inferior at the point at which the exception is caught.
2594 This functionality requires a change in the exception handling
2595 code that was introduced in GCC 4.5.
2597 * GDB now follows GCC's rules on accessing volatile objects when
2598 reading or writing target state during expression evaluation.
2599 One notable difference to prior behavior is that "print x = 0"
2600 no longer generates a read of x; the value of the assignment is
2601 now always taken directly from the value being assigned.
2603 * GDB now has some support for using labels in the program's source in
2604 linespecs. For instance, you can use "advance label" to continue
2605 execution to a label.
2607 * GDB now has support for reading and writing a new .gdb_index
2608 section. This section holds a fast index of DWARF debugging
2609 information and can be used to greatly speed up GDB startup and
2610 operation. See the documentation for `save gdb-index' for details.
2612 * The "watch" command now accepts an optional "-location" argument.
2613 When used, this causes GDB to watch the memory referred to by the
2614 expression. Such a watchpoint is never deleted due to it going out
2617 * GDB now supports thread debugging of core dumps on GNU/Linux.
2619 GDB now activates thread debugging using the libthread_db library
2620 when debugging GNU/Linux core dumps, similarly to when debugging
2621 live processes. As a result, when debugging a core dump file, GDB
2622 is now able to display pthread_t ids of threads. For example, "info
2623 threads" shows the same output as when debugging the process when it
2624 was live. In earlier releases, you'd see something like this:
2627 * 1 LWP 6780 main () at main.c:10
2629 While now you see this:
2632 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2634 It is also now possible to inspect TLS variables when debugging core
2637 When debugging a core dump generated on a machine other than the one
2638 used to run GDB, you may need to point GDB at the correct
2639 libthread_db library with the "set libthread-db-search-path"
2640 command. See the user manual for more details on this command.
2642 * When natively debugging programs on PowerPC BookE processors running
2643 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2644 which stop execution of the inferior whenever it executes an instruction
2645 at any address within the specified range. See the "PowerPC Embedded"
2646 section in the user manual for more details.
2648 * New features in the GDB remote stub, GDBserver
2650 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2651 and i686 LynxOS (version 5.x).
2653 ** GDBserver is now supported on Blackfin Linux.
2655 * New native configurations
2657 ia64 HP-UX ia64-*-hpux*
2661 Analog Devices, Inc. Blackfin Processor bfin-*
2663 * Ada task switching is now supported on sparc-elf targets when
2664 debugging a program using the Ravenscar Profile. For more information,
2665 see the "Tasking Support when using the Ravenscar Profile" section
2666 in the GDB user manual.
2668 * Guile support was removed.
2670 * New features in the GNU simulator
2672 ** The --map-info flag lists all known core mappings.
2674 ** CFI flashes may be simulated via the "cfi" device.
2676 *** Changes in GDB 7.2
2678 * Shared library support for remote targets by default
2680 When GDB is configured for a generic, non-OS specific target, like
2681 for example, --target=arm-eabi or one of the many *-*-elf targets,
2682 GDB now queries remote stubs for loaded shared libraries using the
2683 `qXfer:libraries:read' packet. Previously, shared library support
2684 was always disabled for such configurations.
2688 ** Argument Dependent Lookup (ADL)
2690 In C++ ADL lookup directs function search to the namespaces of its
2691 arguments even if the namespace has not been imported.
2701 Here the compiler will search for `foo' in the namespace of 'b'
2702 and find A::foo. GDB now supports this. This construct is commonly
2703 used in the Standard Template Library for operators.
2705 ** Improved User Defined Operator Support
2707 In addition to member operators, GDB now supports lookup of operators
2708 defined in a namespace and imported with a `using' directive, operators
2709 defined in the global scope, operators imported implicitly from an
2710 anonymous namespace, and the ADL operators mentioned in the previous
2712 GDB now also supports proper overload resolution for all the previously
2713 mentioned flavors of operators.
2715 ** static const class members
2717 Printing of static const class members that are initialized in the
2718 class definition has been fixed.
2720 * Windows Thread Information Block access.
2722 On Windows targets, GDB now supports displaying the Windows Thread
2723 Information Block (TIB) structure. This structure is visible either
2724 by using the new command `info w32 thread-information-block' or, by
2725 dereferencing the new convenience variable named `$_tlb', a
2726 thread-specific pointer to the TIB. This feature is also supported
2727 when remote debugging using GDBserver.
2729 * Static tracepoints
2731 Static tracepoints are calls in the user program into a tracing
2732 library. One such library is a port of the LTTng kernel tracer to
2733 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2734 When debugging with GDBserver, GDB now supports combining the GDB
2735 tracepoint machinery with such libraries. For example: the user can
2736 use GDB to probe a static tracepoint marker (a call from the user
2737 program into the tracing library) with the new "strace" command (see
2738 "New commands" below). This creates a "static tracepoint" in the
2739 breakpoint list, that can be manipulated with the same feature set
2740 as fast and regular tracepoints. E.g., collect registers, local and
2741 global variables, collect trace state variables, and define
2742 tracepoint conditions. In addition, the user can collect extra
2743 static tracepoint marker specific data, by collecting the new
2744 $_sdata internal variable. When analyzing the trace buffer, you can
2745 inspect $_sdata like any other variable available to GDB. For more
2746 information, see the "Tracepoints" chapter in GDB user manual. New
2747 remote packets have been defined to support static tracepoints, see
2748 the "New remote packets" section below.
2750 * Better reconstruction of tracepoints after disconnected tracing
2752 GDB will attempt to download the original source form of tracepoint
2753 definitions when starting a trace run, and then will upload these
2754 upon reconnection to the target, resulting in a more accurate
2755 reconstruction of the tracepoints that are in use on the target.
2759 You can now exercise direct control over the ways that GDB can
2760 affect your program. For instance, you can disallow the setting of
2761 breakpoints, so that the program can run continuously (assuming
2762 non-stop mode). In addition, the "observer" variable is available
2763 to switch all of the different controls; in observer mode, GDB
2764 cannot affect the target's behavior at all, which is useful for
2765 tasks like diagnosing live systems in the field.
2767 * The new convenience variable $_thread holds the number of the
2770 * New remote packets
2774 Return the address of the Windows Thread Information Block of a given thread.
2778 In response to several of the tracepoint packets, the target may now
2779 also respond with a number of intermediate `qRelocInsn' request
2780 packets before the final result packet, to have GDB handle
2781 relocating an instruction to execute at a different address. This
2782 is particularly useful for stubs that support fast tracepoints. GDB
2783 reports support for this feature in the qSupported packet.
2787 List static tracepoint markers in the target program.
2791 List static tracepoint markers at a given address in the target
2794 qXfer:statictrace:read
2796 Read the static trace data collected (by a `collect $_sdata'
2797 tracepoint action). The remote stub reports support for this packet
2798 to gdb's qSupported query.
2802 Send the current settings of GDB's permission flags.
2806 Send part of the source (textual) form of a tracepoint definition,
2807 which includes location, conditional, and action list.
2809 * The source command now accepts a -s option to force searching for the
2810 script in the source search path even if the script name specifies
2813 * New features in the GDB remote stub, GDBserver
2815 - GDBserver now support tracepoints (including fast tracepoints, and
2816 static tracepoints). The feature is currently supported by the
2817 i386-linux and amd64-linux builds. See the "Tracepoints support
2818 in gdbserver" section in the manual for more information.
2820 GDBserver JIT compiles the tracepoint's conditional agent
2821 expression bytecode into native code whenever possible for low
2822 overhead dynamic tracepoints conditionals. For such tracepoints,
2823 an expression that examines program state is evaluated when the
2824 tracepoint is reached, in order to determine whether to capture
2825 trace data. If the condition is simple and false, processing the
2826 tracepoint finishes very quickly and no data is gathered.
2828 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2829 for static tracepoints support.
2831 - GDBserver now supports x86_64 Windows 64-bit debugging.
2833 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2834 it understands register description.
2836 * The --batch flag now disables pagination and queries.
2838 * X86 general purpose registers
2840 GDB now supports reading/writing byte, word and double-word x86
2841 general purpose registers directly. This means you can use, say,
2842 $ah or $ax to refer, respectively, to the byte register AH and
2843 16-bit word register AX that are actually portions of the 32-bit
2844 register EAX or 64-bit register RAX.
2846 * The `commands' command now accepts a range of breakpoints to modify.
2847 A plain `commands' following a command that creates multiple
2848 breakpoints affects all the breakpoints set by that command. This
2849 applies to breakpoints set by `rbreak', and also applies when a
2850 single `break' command creates multiple breakpoints (e.g.,
2851 breakpoints on overloaded c++ functions).
2853 * The `rbreak' command now accepts a filename specification as part of
2854 its argument, limiting the functions selected by the regex to those
2855 in the specified file.
2857 * Support for remote debugging Windows and SymbianOS shared libraries
2858 from Unix hosts has been improved. Non Windows GDB builds now can
2859 understand target reported file names that follow MS-DOS based file
2860 system semantics, such as file names that include drive letters and
2861 use the backslash character as directory separator. This makes it
2862 possible to transparently use the "set sysroot" and "set
2863 solib-search-path" on Unix hosts to point as host copies of the
2864 target's shared libraries. See the new command "set
2865 target-file-system-kind" described below, and the "Commands to
2866 specify files" section in the user manual for more information.
2870 eval template, expressions...
2871 Convert the values of one or more expressions under the control
2872 of the string template to a command line, and call it.
2874 set target-file-system-kind unix|dos-based|auto
2875 show target-file-system-kind
2876 Set or show the assumed file system kind for target reported file
2879 save breakpoints <filename>
2880 Save all current breakpoint definitions to a file suitable for use
2881 in a later debugging session. To read the saved breakpoint
2882 definitions, use the `source' command.
2884 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2887 info static-tracepoint-markers
2888 Display information about static tracepoint markers in the target.
2890 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2891 Define a static tracepoint by probing a marker at the given
2892 function, line, address, or marker ID.
2896 Enable and disable observer mode.
2898 set may-write-registers on|off
2899 set may-write-memory on|off
2900 set may-insert-breakpoints on|off
2901 set may-insert-tracepoints on|off
2902 set may-insert-fast-tracepoints on|off
2903 set may-interrupt on|off
2904 Set individual permissions for GDB effects on the target. Note that
2905 some of these settings can have undesirable or surprising
2906 consequences, particularly when changed in the middle of a session.
2907 For instance, disabling the writing of memory can prevent
2908 breakpoints from being inserted, cause single-stepping to fail, or
2909 even crash your program, if you disable after breakpoints have been
2910 inserted. However, GDB should not crash.
2912 set record memory-query on|off
2913 show record memory-query
2914 Control whether to stop the inferior if memory changes caused
2915 by an instruction cannot be recorded.
2920 The disassemble command now supports "start,+length" form of two arguments.
2924 ** GDB now provides a new directory location, called the python directory,
2925 where Python scripts written for GDB can be installed. The location
2926 of that directory is <data-directory>/python, where <data-directory>
2927 is the GDB data directory. For more details, see section `Scripting
2928 GDB using Python' in the manual.
2930 ** The GDB Python API now has access to breakpoints, symbols, symbol
2931 tables, program spaces, inferiors, threads and frame's code blocks.
2932 Additionally, GDB Parameters can now be created from the API, and
2933 manipulated via set/show in the CLI.
2935 ** New functions gdb.target_charset, gdb.target_wide_charset,
2936 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2938 ** New exception gdb.GdbError.
2940 ** Pretty-printers are now also looked up in the current program space.
2942 ** Pretty-printers can now be individually enabled and disabled.
2944 ** GDB now looks for names of Python scripts to auto-load in a
2945 special section named `.debug_gdb_scripts', in addition to looking
2946 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2948 * Tracepoint actions were unified with breakpoint commands. In particular,
2949 there are no longer differences in "info break" output for breakpoints and
2950 tracepoints and the "commands" command can be used for both tracepoints and
2951 regular breakpoints.
2955 ARM Symbian arm*-*-symbianelf*
2957 * D language support.
2958 GDB now supports debugging programs written in the D programming
2961 * GDB now supports the extended ptrace interface for PowerPC which is
2962 available since Linux kernel version 2.6.34. This automatically enables
2963 any hardware breakpoints and additional hardware watchpoints available in
2964 the processor. The old ptrace interface exposes just one hardware
2965 watchpoint and no hardware breakpoints.
2967 * GDB is now able to use the Data Value Compare (DVC) register available on
2968 embedded PowerPC processors to implement in hardware simple watchpoint
2969 conditions of the form:
2971 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2973 This works in native GDB running on Linux kernels with the extended ptrace
2974 interface mentioned above.
2976 *** Changes in GDB 7.1
2980 ** Namespace Support
2982 GDB now supports importing of namespaces in C++. This enables the
2983 user to inspect variables from imported namespaces. Support for
2984 namepace aliasing has also been added. So, if a namespace is
2985 aliased in the current scope (e.g. namepace C=A; ) the user can
2986 print variables using the alias (e.g. (gdb) print C::x).
2990 All known bugs relating to the printing of virtual base class were
2991 fixed. It is now possible to call overloaded static methods using a
2996 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
2997 and reinterpret_cast<> are now handled by the C++ expression parser.
3001 Xilinx MicroBlaze microblaze-*-*
3006 Xilinx MicroBlaze microblaze
3009 * Multi-program debugging.
3011 GDB now has support for multi-program (a.k.a. multi-executable or
3012 multi-exec) debugging. This allows for debugging multiple inferiors
3013 simultaneously each running a different program under the same GDB
3014 session. See "Debugging Multiple Inferiors and Programs" in the
3015 manual for more information. This implied some user visible changes
3016 in the multi-inferior support. For example, "info inferiors" now
3017 lists inferiors that are not running yet or that have exited
3018 already. See also "New commands" and "New options" below.
3020 * New tracing features
3022 GDB's tracepoint facility now includes several new features:
3024 ** Trace state variables
3026 GDB tracepoints now include support for trace state variables, which
3027 are variables managed by the target agent during a tracing
3028 experiment. They are useful for tracepoints that trigger each
3029 other, so for instance one tracepoint can count hits in a variable,
3030 and then a second tracepoint has a condition that is true when the
3031 count reaches a particular value. Trace state variables share the
3032 $-syntax of GDB convenience variables, and can appear in both
3033 tracepoint actions and condition expressions. Use the "tvariable"
3034 command to create, and "info tvariables" to view; see "Trace State
3035 Variables" in the manual for more detail.
3039 GDB now includes an option for defining fast tracepoints, which
3040 targets may implement more efficiently, such as by installing a jump
3041 into the target agent rather than a trap instruction. The resulting
3042 speedup can be by two orders of magnitude or more, although the
3043 tradeoff is that some program locations on some target architectures
3044 might not allow fast tracepoint installation, for instance if the
3045 instruction to be replaced is shorter than the jump. To request a
3046 fast tracepoint, use the "ftrace" command, with syntax identical to
3047 the regular trace command.
3049 ** Disconnected tracing
3051 It is now possible to detach GDB from the target while it is running
3052 a trace experiment, then reconnect later to see how the experiment
3053 is going. In addition, a new variable disconnected-tracing lets you
3054 tell the target agent whether to continue running a trace if the
3055 connection is lost unexpectedly.
3059 GDB now has the ability to save the trace buffer into a file, and
3060 then use that file as a target, similarly to you can do with
3061 corefiles. You can select trace frames, print data that was
3062 collected in them, and use tstatus to display the state of the
3063 tracing run at the moment that it was saved. To create a trace
3064 file, use "tsave <filename>", and to use it, do "target tfile
3067 ** Circular trace buffer
3069 You can ask the target agent to handle the trace buffer as a
3070 circular buffer, discarding the oldest trace frames to make room for
3071 newer ones, by setting circular-trace-buffer to on. This feature may
3072 not be available for all target agents.
3077 The disassemble command, when invoked with two arguments, now requires
3078 the arguments to be comma-separated.
3081 The info variables command now displays variable definitions. Files
3082 which only declare a variable are not shown.
3085 The source command is now capable of sourcing Python scripts.
3086 This feature is dependent on the debugger being build with Python
3089 Related to this enhancement is also the introduction of a new command
3090 "set script-extension" (see below).
3092 * New commands (for set/show, see "New options" below)
3094 record save [<FILENAME>]
3095 Save a file (in core file format) containing the process record
3096 execution log for replay debugging at a later time.
3098 record restore <FILENAME>
3099 Restore the process record execution log that was saved at an
3100 earlier time, for replay debugging.
3102 add-inferior [-copies <N>] [-exec <FILENAME>]
3105 clone-inferior [-copies <N>] [ID]
3106 Make a new inferior ready to execute the same program another
3107 inferior has loaded.
3112 maint info program-spaces
3113 List the program spaces loaded into GDB.
3115 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3116 show remote interrupt-sequence
3117 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3118 as the sequence to the remote target in order to interrupt the execution.
3119 Ctrl-C is a default. Some system prefers BREAK which is high level of
3120 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3121 Magic SysRq g. It is BREAK signal and character 'g'.
3123 set remote interrupt-on-connect [on | off]
3124 show remote interrupt-on-connect
3125 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3126 remote target when gdb connects to it. This is needed when you debug
3129 set remotebreak [on | off]
3131 Deprecated. Use "set/show remote interrupt-sequence" instead.
3133 tvariable $NAME [ = EXP ]
3134 Create or modify a trace state variable.
3137 List trace state variables and their values.
3139 delete tvariable $NAME ...
3140 Delete one or more trace state variables.
3143 Evaluate the given expressions without collecting anything into the
3144 trace buffer. (Valid in tracepoint actions only.)
3146 ftrace FN / FILE:LINE / *ADDR
3147 Define a fast tracepoint at the given function, line, or address.
3149 * New expression syntax
3151 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3152 GDB now parses 0b101010 identically with 42.
3156 set follow-exec-mode new|same
3157 show follow-exec-mode
3158 Control whether GDB reuses the same inferior across an exec call or
3159 creates a new one. This is useful to be able to restart the old
3160 executable after the inferior having done an exec call.
3162 set default-collect EXPR, ...
3163 show default-collect
3164 Define a list of expressions to be collected at each tracepoint.
3165 This is a useful way to ensure essential items are not overlooked,
3166 such as registers or a critical global variable.
3168 set disconnected-tracing
3169 show disconnected-tracing
3170 If set to 1, the target is instructed to continue tracing if it
3171 loses its connection to GDB. If 0, the target is to stop tracing
3174 set circular-trace-buffer
3175 show circular-trace-buffer
3176 If set to on, the target is instructed to use a circular trace buffer
3177 and discard the oldest trace frames instead of stopping the trace due
3178 to a full trace buffer. If set to off, the trace stops when the buffer
3179 fills up. Some targets may not support this.
3181 set script-extension off|soft|strict
3182 show script-extension
3183 If set to "off", the debugger does not perform any script language
3184 recognition, and all sourced files are assumed to be GDB scripts.
3185 If set to "soft" (the default), files are sourced according to
3186 filename extension, falling back to GDB scripts if the first
3188 If set to "strict", files are sourced according to filename extension.
3190 set ada trust-PAD-over-XVS on|off
3191 show ada trust-PAD-over-XVS
3192 If off, activate a workaround against a bug in the debugging information
3193 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3194 the GCC sources for more information about the GNAT encoding and
3195 PAD types in particular). It is always safe to set this option to
3196 off, but this introduces a slight performance penalty. The default
3199 * Python API Improvements
3201 ** GDB provides the new class gdb.LazyString. This is useful in
3202 some pretty-printing cases. The new method gdb.Value.lazy_string
3203 provides a simple way to create objects of this type.
3205 ** The fields returned by gdb.Type.fields now have an
3206 `is_base_class' attribute.
3208 ** The new method gdb.Type.range returns the range of an array type.
3210 ** The new method gdb.parse_and_eval can be used to parse and
3211 evaluate an expression.
3213 * New remote packets
3216 Define a trace state variable.
3219 Get the current value of a trace state variable.
3222 Set desired tracing behavior upon disconnection.
3225 Set the trace buffer to be linear or circular.
3228 Get data about the tracepoints currently in use.
3232 Process record now works correctly with hardware watchpoints.
3234 Multiple bug fixes have been made to the mips-irix port, making it
3235 much more reliable. In particular:
3236 - Debugging threaded applications is now possible again. Previously,
3237 GDB would hang while starting the program, or while waiting for
3238 the program to stop at a breakpoint.
3239 - Attaching to a running process no longer hangs.
3240 - An error occurring while loading a core file has been fixed.
3241 - Changing the value of the PC register now works again. This fixes
3242 problems observed when using the "jump" command, or when calling
3243 a function from GDB, or even when assigning a new value to $pc.
3244 - With the "finish" and "return" commands, the return value for functions
3245 returning a small array is now correctly printed.
3246 - It is now possible to break on shared library code which gets executed
3247 during a shared library init phase (code executed while executing
3248 their .init section). Previously, the breakpoint would have no effect.
3249 - GDB is now able to backtrace through the signal handler for
3250 non-threaded programs.
3252 PIE (Position Independent Executable) programs debugging is now supported.
3253 This includes debugging execution of PIC (Position Independent Code) shared
3254 libraries although for that, it should be possible to run such libraries as an
3257 *** Changes in GDB 7.0
3259 * GDB now has an interface for JIT compilation. Applications that
3260 dynamically generate code can create symbol files in memory and register
3261 them with GDB. For users, the feature should work transparently, and
3262 for JIT developers, the interface is documented in the GDB manual in the
3263 "JIT Compilation Interface" chapter.
3265 * Tracepoints may now be conditional. The syntax is as for
3266 breakpoints; either an "if" clause appended to the "trace" command,
3267 or the "condition" command is available. GDB sends the condition to
3268 the target for evaluation using the same bytecode format as is used
3269 for tracepoint actions.
3271 * The disassemble command now supports: an optional /r modifier, print the
3272 raw instructions in hex as well as in symbolic form, and an optional /m
3273 modifier to print mixed source+assembly.
3275 * Process record and replay
3277 In a architecture environment that supports ``process record and
3278 replay'', ``process record and replay'' target can record a log of
3279 the process execution, and replay it with both forward and reverse
3282 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3283 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3284 set execution-direction {forward|reverse}, for targets that support
3287 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3288 feature is available with a native GDB running on kernel version
3291 * GDB now has support for multi-byte and wide character sets on the
3292 target. Strings whose character type is wchar_t, char16_t, or
3293 char32_t are now correctly printed. GDB supports wide- and unicode-
3294 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3295 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3296 `printf'. This feature requires iconv to work properly; if your
3297 system does not have a working iconv, GDB can use GNU libiconv. See
3298 the installation instructions for more information.
3300 * GDB now supports automatic retrieval of shared library files from
3301 remote targets. To use this feature, specify a system root that begins
3302 with the `remote:' prefix, either via the `set sysroot' command or via
3303 the `--with-sysroot' configure-time option.
3305 * "info sharedlibrary" now takes an optional regex of libraries to show,
3306 and it now reports if a shared library has no debugging information.
3308 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3309 now complete on file names.
3311 * When completing in expressions, gdb will attempt to limit
3312 completions to allowable structure or union fields, where appropriate.
3313 For instance, consider:
3315 # struct example { int f1; double f2; };
3316 # struct example variable;
3319 If the user types TAB at the end of this command line, the available
3320 completions will be "f1" and "f2".
3322 * Inlined functions are now supported. They show up in backtraces, and
3323 the "step", "next", and "finish" commands handle them automatically.
3325 * GDB now supports the token-splicing (##) and stringification (#)
3326 operators when expanding macros. It also supports variable-arity
3329 * GDB now supports inspecting extra signal information, exported by
3330 the new $_siginfo convenience variable. The feature is currently
3331 implemented on linux ARM, i386 and amd64.
3333 * GDB can now display the VFP floating point registers and NEON vector
3334 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3335 can provide these registers (requires Linux 2.6.30 or later). Remote
3336 and simulator targets may also provide them.
3338 * New remote packets
3341 Search memory for a sequence of bytes.
3344 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3345 operation over reliable transport links. Use of this packet is
3346 controlled by the `set remote noack-packet' command.
3349 Kill the process with the specified process ID. Use this in preference
3350 to `k' when multiprocess protocol extensions are supported.
3353 Obtains additional operating system information
3357 Read or write additional signal information.
3359 * Removed remote protocol undocumented extension
3361 An undocumented extension to the remote protocol's `S' stop reply
3362 packet that permited the stub to pass a process id was removed.
3363 Remote servers should use the `T' stop reply packet instead.
3365 * GDB now supports multiple function calling conventions according to the
3366 DWARF-2 DW_AT_calling_convention function attribute.
3368 * The SH target utilizes the aforementioned change to distinguish between gcc
3369 and Renesas calling convention. It also adds the new CLI commands
3370 `set/show sh calling-convention'.
3372 * GDB can now read compressed debug sections, as produced by GNU gold
3373 with the --compress-debug-sections=zlib flag.
3375 * 64-bit core files are now supported on AIX.
3377 * Thread switching is now supported on Tru64.
3379 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3380 which will be allocated using malloc later in program execution.
3382 * The qXfer:libraries:read remote procotol packet now allows passing a
3383 list of section offsets.
3385 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3386 conditions handling signals delivered during attach or thread creation
3387 have also been fixed.
3389 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3390 From the user's standpoint, all unqualified instances of True and False
3391 are treated as the standard definitions, regardless of context.
3393 * GDB now parses C++ symbol and type names more flexibly. For
3396 template<typename T> class C { };
3399 GDB will now correctly handle all of:
3401 ptype C<char const *>
3402 ptype C<char const*>
3403 ptype C<const char *>
3404 ptype C<const char*>
3406 * New features in the GDB remote stub, gdbserver
3408 - The "--wrapper" command-line argument tells gdbserver to use a
3409 wrapper program to launch programs for debugging.
3411 - On PowerPC and S/390 targets, it is now possible to use a single
3412 gdbserver executable to debug both 32-bit and 64-bit programs.
3413 (This requires gdbserver itself to be built as a 64-bit executable.)
3415 - gdbserver uses the new noack protocol mode for TCP connections to
3416 reduce communications latency, if also supported and enabled in GDB.
3418 - Support for the sparc64-linux-gnu target is now included in
3421 - The amd64-linux build of gdbserver now supports debugging both
3422 32-bit and 64-bit programs.
3424 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3425 now support hardware watchpoints, and will use them automatically
3430 GDB now has support for scripting using Python. Whether this is
3431 available is determined at configure time.
3433 New GDB commands can now be written in Python.
3435 * Ada tasking support
3437 Ada tasks can now be inspected in GDB. The following commands have
3441 Print the list of Ada tasks.
3443 Print detailed information about task number N.
3445 Print the task number of the current task.
3447 Switch the context of debugging to task number N.
3449 * Support for user-defined prefixed commands. The "define" command can
3450 add new commands to existing prefixes, e.g. "target".
3452 * Multi-inferior, multi-process debugging.
3454 GDB now has generalized support for multi-inferior debugging. See
3455 "Debugging Multiple Inferiors" in the manual for more information.
3456 Although availability still depends on target support, the command
3457 set is more uniform now. The GNU/Linux specific multi-forks support
3458 has been migrated to this new framework. This implied some user
3459 visible changes; see "New commands" and also "Removed commands"
3462 * Target descriptions can now describe the target OS ABI. See the
3463 "Target Description Format" section in the user manual for more
3466 * Target descriptions can now describe "compatible" architectures
3467 to indicate that the target can execute applications for a different
3468 architecture in addition to those for the main target architecture.
3469 See the "Target Description Format" section in the user manual for
3472 * Multi-architecture debugging.
3474 GDB now includes general supports for debugging applications on
3475 hybrid systems that use more than one single processor architecture
3476 at the same time. Each such hybrid architecture still requires
3477 specific support to be added. The only hybrid architecture supported
3478 in this version of GDB is the Cell Broadband Engine.
3480 * GDB now supports integrated debugging of Cell/B.E. applications that
3481 use both the PPU and SPU architectures. To enable support for hybrid
3482 Cell/B.E. debugging, you need to configure GDB to support both the
3483 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3484 --enable-targets configure option.
3486 * Non-stop mode debugging.
3488 For some targets, GDB now supports an optional mode of operation in
3489 which you can examine stopped threads while other threads continue
3490 to execute freely. This is referred to as non-stop mode, with the
3491 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3492 section in the user manual for more information.
3494 To be able to support remote non-stop debugging, a remote stub needs
3495 to implement the non-stop mode remote protocol extensions, as
3496 described in the "Remote Non-Stop" section of the user manual. The
3497 GDB remote stub, gdbserver, has been adjusted to support these
3498 extensions on linux targets.
3500 * New commands (for set/show, see "New options" below)
3502 catch syscall [NAME(S) | NUMBER(S)]
3503 Catch system calls. Arguments, which should be names of system
3504 calls or their numbers, mean catch only those syscalls. Without
3505 arguments, every syscall will be caught. When the inferior issues
3506 any of the specified syscalls, GDB will stop and announce the system
3507 call, both when it is called and when its call returns. This
3508 feature is currently available with a native GDB running on the
3509 Linux Kernel, under the following architectures: x86, x86_64,
3510 PowerPC and PowerPC64.
3512 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3514 Search memory for a sequence of bytes.
3516 maint set python print-stack
3517 maint show python print-stack
3518 Show a stack trace when an error is encountered in a Python script.
3521 Invoke CODE by passing it to the Python interpreter.
3526 These allow macros to be defined, undefined, and listed
3530 Show operating system information about processes.
3533 List the inferiors currently under GDB's control.
3536 Switch focus to inferior number NUM.
3539 Detach from inferior number NUM.
3542 Kill inferior number NUM.
3546 set spu stop-on-load
3547 show spu stop-on-load
3548 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3550 set spu auto-flush-cache
3551 show spu auto-flush-cache
3552 Control whether to automatically flush the software-managed cache
3553 during Cell/B.E. debugging.
3555 set sh calling-convention
3556 show sh calling-convention
3557 Control the calling convention used when calling SH target functions.
3560 show debug timestamp
3561 Control display of timestamps with GDB debugging output.
3563 set disassemble-next-line
3564 show disassemble-next-line
3565 Control display of disassembled source lines or instructions when
3568 set remote noack-packet
3569 show remote noack-packet
3570 Set/show the use of remote protocol QStartNoAckMode packet. See above
3571 under "New remote packets."
3573 set remote query-attached-packet
3574 show remote query-attached-packet
3575 Control use of remote protocol `qAttached' (query-attached) packet.
3577 set remote read-siginfo-object
3578 show remote read-siginfo-object
3579 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3582 set remote write-siginfo-object
3583 show remote write-siginfo-object
3584 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3587 set remote reverse-continue
3588 show remote reverse-continue
3589 Control use of remote protocol 'bc' (reverse-continue) packet.
3591 set remote reverse-step
3592 show remote reverse-step
3593 Control use of remote protocol 'bs' (reverse-step) packet.
3595 set displaced-stepping
3596 show displaced-stepping
3597 Control displaced stepping mode. Displaced stepping is a way to
3598 single-step over breakpoints without removing them from the debuggee.
3599 Also known as "out-of-line single-stepping".
3602 show debug displaced
3603 Control display of debugging info for displaced stepping.
3605 maint set internal-error
3606 maint show internal-error
3607 Control what GDB does when an internal error is detected.
3609 maint set internal-warning
3610 maint show internal-warning
3611 Control what GDB does when an internal warning is detected.
3616 Use a wrapper program to launch programs for debugging.
3618 set multiple-symbols (all|ask|cancel)
3619 show multiple-symbols
3620 The value of this variable can be changed to adjust the debugger behavior
3621 when an expression or a breakpoint location contains an ambiguous symbol
3622 name (an overloaded function name, for instance).
3624 set breakpoint always-inserted
3625 show breakpoint always-inserted
3626 Keep breakpoints always inserted in the target, as opposed to inserting
3627 them when resuming the target, and removing them when the target stops.
3628 This option can improve debugger performance on slow remote targets.
3630 set arm fallback-mode (arm|thumb|auto)
3631 show arm fallback-mode
3632 set arm force-mode (arm|thumb|auto)
3634 These commands control how ARM GDB determines whether instructions
3635 are ARM or Thumb. The default for both settings is auto, which uses
3636 the current CPSR value for instructions without symbols; previous
3637 versions of GDB behaved as if "set arm fallback-mode arm".
3639 set disable-randomization
3640 show disable-randomization
3641 Standalone programs run with the virtual address space randomization enabled
3642 by default on some platforms. This option keeps the addresses stable across
3643 multiple debugging sessions.
3647 Control whether other threads are stopped or not when some thread hits
3652 Requests that asynchronous execution is enabled in the target, if available.
3653 In this case, it's possible to resume target in the background, and interact
3654 with GDB while the target is running. "show target-async" displays the
3655 current state of asynchronous execution of the target.
3657 set target-wide-charset
3658 show target-wide-charset
3659 The target-wide-charset is the name of the character set that GDB
3660 uses when printing characters whose type is wchar_t.
3662 set tcp auto-retry (on|off)
3664 set tcp connect-timeout
3665 show tcp connect-timeout
3666 These commands allow GDB to retry failed TCP connections to a remote stub
3667 with a specified timeout period; this is useful if the stub is launched
3668 in parallel with GDB but may not be ready to accept connections immediately.
3670 set libthread-db-search-path
3671 show libthread-db-search-path
3672 Control list of directories which GDB will search for appropriate
3675 set schedule-multiple (on|off)
3676 show schedule-multiple
3677 Allow GDB to resume all threads of all processes or only threads of
3678 the current process.
3682 Use more aggressive caching for accesses to the stack. This improves
3683 performance of remote debugging (particularly backtraces) without
3684 affecting correctness.
3686 set interactive-mode (on|off|auto)
3687 show interactive-mode
3688 Control whether GDB runs in interactive mode (on) or not (off).
3689 When in interactive mode, GDB waits for the user to answer all
3690 queries. Otherwise, GDB does not wait and assumes the default
3691 answer. When set to auto (the default), GDB determines which
3692 mode to use based on the stdin settings.
3697 For program forks, this is replaced by the new more generic `info
3698 inferiors' command. To list checkpoints, you can still use the
3699 `info checkpoints' command, which was an alias for the `info forks'
3703 Replaced by the new `inferior' command. To switch between
3704 checkpoints, you can still use the `restart' command, which was an
3705 alias for the `fork' command.
3708 This is removed, since some targets don't have a notion of
3709 processes. To switch between processes, you can still use the
3710 `inferior' command using GDB's own inferior number.
3713 For program forks, this is replaced by the new more generic `kill
3714 inferior' command. To delete a checkpoint, you can still use the
3715 `delete checkpoint' command, which was an alias for the `delete
3719 For program forks, this is replaced by the new more generic `detach
3720 inferior' command. To detach a checkpoint, you can still use the
3721 `detach checkpoint' command, which was an alias for the `detach
3724 * New native configurations
3726 x86/x86_64 Darwin i[34567]86-*-darwin*
3728 x86_64 MinGW x86_64-*-mingw*
3732 Lattice Mico32 lm32-*
3733 x86 DICOS i[34567]86-*-dicos*
3734 x86_64 DICOS x86_64-*-dicos*
3737 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3738 (mingw32ce) debugging.
3744 These commands were actually not implemented on any target.
3746 *** Changes in GDB 6.8
3748 * New native configurations
3750 NetBSD/hppa hppa*-*netbsd*
3751 Xtensa GNU/Linux xtensa*-*-linux*
3755 NetBSD/hppa hppa*-*-netbsd*
3756 Xtensa GNU/Lunux xtensa*-*-linux*
3758 * Change in command line behavior -- corefiles vs. process ids.
3760 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3761 attaching to process NUMBER fails, GDB no longer attempts to open a
3762 core file named NUMBER. Attaching to a program using the -c option
3763 is no longer supported. Instead, use the '-p' or '--pid' options.
3765 * GDB can now be built as a native debugger for debugging Windows x86
3766 (mingw32) Portable Executable (PE) programs.
3768 * Pending breakpoints no longer change their number when their address
3771 * GDB now supports breakpoints with multiple locations,
3772 including breakpoints on C++ constructors, inside C++ templates,
3773 and in inlined functions.
3775 * GDB's ability to debug optimized code has been improved. GDB more
3776 accurately identifies function bodies and lexical blocks that occupy
3777 more than one contiguous range of addresses.
3779 * Target descriptions can now describe registers for PowerPC.
3781 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3782 registers on PowerPC targets.
3784 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3785 targets even when the libthread_db library is not available.
3787 * The GDB remote stub, gdbserver, now supports the new file transfer
3788 commands (remote put, remote get, and remote delete).
3790 * The GDB remote stub, gdbserver, now supports run and attach in
3791 extended-remote mode.
3793 * hppa*64*-*-hpux11* target broken
3794 The debugger is unable to start a program and fails with the following
3795 error: "Error trying to get information about dynamic linker".
3796 The gdb-6.7 release is also affected.
3798 * GDB now supports the --enable-targets= configure option to allow
3799 building a single GDB executable that supports multiple remote
3800 target architectures.
3802 * GDB now supports debugging C and C++ programs which use the
3803 Decimal Floating Point extension. In addition, the PowerPC target
3804 now has a set of pseudo-registers to inspect decimal float values
3805 stored in two consecutive float registers.
3807 * The -break-insert MI command can optionally create pending
3810 * Improved support for debugging Ada
3811 Many improvements to the Ada language support have been made. These
3813 - Better support for Ada2005 interface types
3814 - Improved handling of arrays and slices in general
3815 - Better support for Taft-amendment types
3816 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3818 - Improved command completion in Ada
3821 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3826 set print frame-arguments (all|scalars|none)
3827 show print frame-arguments
3828 The value of this variable can be changed to control which argument
3829 values should be printed by the debugger when displaying a frame.
3834 Transfer files to and from a remote target, and delete remote files.
3841 Transfer files to and from a remote target, and delete remote files.
3843 * New remote packets
3850 Open, close, read, write, and delete files on the remote system.
3853 Attach to an existing process on the remote system, in extended-remote
3857 Run a new process on the remote system, in extended-remote mode.
3859 *** Changes in GDB 6.7
3861 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3862 bfd, libiberty and opcodes, as revealed by static analysis donated by
3863 Coverity, Inc. (http://scan.coverity.com).
3865 * When looking up multiply-defined global symbols, GDB will now prefer the
3866 symbol definition in the current shared library if it was built using the
3867 -Bsymbolic linker option.
3869 * When the Text User Interface (TUI) is not configured, GDB will now
3870 recognize the -tui command-line option and print a message that the TUI
3873 * The GDB remote stub, gdbserver, now has lower overhead for high
3874 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3876 * GDB for MIPS targets now autodetects whether a remote target provides
3877 32-bit or 64-bit register values.
3879 * Support for C++ member pointers has been improved.
3881 * GDB now understands XML target descriptions, which specify the
3882 target's overall architecture. GDB can read a description from
3883 a local file or over the remote serial protocol.
3885 * Vectors of single-byte data use a new integer type which is not
3886 automatically displayed as character or string data.
3888 * The /s format now works with the print command. It displays
3889 arrays of single-byte integers and pointers to single-byte integers
3892 * Target descriptions can now describe target-specific registers,
3893 for architectures which have implemented the support (currently
3894 only ARM, M68K, and MIPS).
3896 * GDB and the GDB remote stub, gdbserver, now support the XScale
3899 * The GDB remote stub, gdbserver, has been updated to support
3900 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3901 has been rewritten to use the standard GDB remote protocol.
3903 * GDB can now step into C++ functions which are called through thunks.
3905 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3907 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3908 layout. It also supports a TextSeg= and DataSeg= response when only
3909 segment base addresses (rather than offsets) are available.
3911 * The /i format now outputs any trailing branch delay slot instructions
3912 immediately following the last instruction within the count specified.
3914 * The GDB remote protocol "T" stop reply packet now supports a
3915 "library" response. Combined with the new "qXfer:libraries:read"
3916 packet, this response allows GDB to debug shared libraries on targets
3917 where the operating system manages the list of loaded libraries (e.g.
3918 Windows and SymbianOS).
3920 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3921 (DLLs) on Windows and Windows CE targets.
3923 * GDB now supports a faster verification that a .debug file matches its binary
3924 according to its build-id signature, if the signature is present.
3930 Enable or disable hardware flow control (RTS/CTS) on the serial port
3931 when debugging using remote targets.
3933 set mem inaccessible-by-default
3934 show mem inaccessible-by-default
3935 If the target supplies a memory map, for instance via the remote
3936 protocol's "qXfer:memory-map:read" packet, setting this variable
3937 prevents GDB from accessing memory outside the memory map. This
3938 is useful for targets with memory mapped registers or which react
3939 badly to accesses of unmapped address space.
3941 set breakpoint auto-hw
3942 show breakpoint auto-hw
3943 If the target supplies a memory map, for instance via the remote
3944 protocol's "qXfer:memory-map:read" packet, setting this variable
3945 lets GDB use hardware breakpoints automatically for memory regions
3946 where it can not use software breakpoints. This covers both the
3947 "break" command and internal breakpoints used for other commands
3948 including "next" and "finish".
3951 catch exception unhandled
3952 Stop the program execution when Ada exceptions are raised.
3955 Stop the program execution when an Ada assertion failed.
3959 Set an alternate system root for target files. This is a more
3960 general version of "set solib-absolute-prefix", which is now
3961 an alias to "set sysroot".
3964 Provide extended SPU facility status information. This set of
3965 commands is available only when debugging the Cell/B.E. SPU
3968 * New native configurations
3970 OpenBSD/sh sh*-*openbsd*
3973 unset tdesc filename
3975 Use the specified local file as an XML target description, and do
3976 not query the target for its built-in description.
3980 OpenBSD/sh sh*-*-openbsd*
3981 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3982 Toshiba Media Processor mep-elf
3984 * New remote packets
3987 Ignore the specified signals; pass them directly to the debugged program
3988 without stopping other threads or reporting them to GDB.
3990 qXfer:features:read:
3991 Read an XML target description from the target, which describes its
3996 Read or write contents of an spufs file on the target system. These
3997 packets are available only on the Cell/B.E. SPU architecture.
3999 qXfer:libraries:read:
4000 Report the loaded shared libraries. Combined with new "T" packet
4001 response, this packet allows GDB to debug shared libraries on
4002 targets where the operating system manages the list of loaded
4003 libraries (e.g. Windows and SymbianOS).
4007 Support for these obsolete configurations has been removed.
4015 i[34567]86-*-lynxos*
4016 i[34567]86-*-netware*
4017 i[34567]86-*-sco3.2v5*
4018 i[34567]86-*-sco3.2v4*
4020 i[34567]86-*-sysv4.2*
4023 i[34567]86-*-unixware2*
4024 i[34567]86-*-unixware*
4033 * Other removed features
4040 Various m68k-only ROM monitors.
4047 Various Renesas ROM monitors and debugging interfaces for SH and
4052 Support for a Macraigor serial interface to on-chip debugging.
4053 GDB does not directly support the newer parallel or USB
4058 A debug information format. The predecessor to DWARF 2 and
4059 DWARF 3, which are still supported.
4061 Support for the HP aCC compiler on HP-UX/PA-RISC
4063 SOM-encapsulated symbolic debugging information, automatic
4064 invocation of pxdb, and the aCC custom C++ ABI. This does not
4065 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4066 with aCC can still be debugged on an assembly level.
4068 MIPS ".pdr" sections
4070 A MIPS-specific format used to describe stack frame layout
4071 in debugging information.
4075 GDB could work with an older version of Guile to debug
4076 the interpreter and Scheme programs running in it.
4078 set mips stack-arg-size
4079 set mips saved-gpreg-size
4081 Use "set mips abi" to control parameter passing for MIPS.
4083 *** Changes in GDB 6.6
4088 Cell Broadband Engine SPU spu-elf
4090 * GDB can now be configured as a cross-debugger targeting native Windows
4091 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4092 running on a Windows system over TCP/IP to debug Windows programs.
4094 * The GDB remote stub, gdbserver, has been updated to support Windows and
4095 Cygwin debugging. Both single-threaded and multi-threaded programs are
4098 * The "set trust-readonly-sections" command works again. This command was
4099 broken in GDB 6.3, 6.4, and 6.5.
4101 * The "load" command now supports writing to flash memory, if the remote
4102 stub provides the required support.
4104 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4105 longer requires symbolic debug information (e.g. DWARF-2).
4110 unset substitute-path
4111 show substitute-path
4112 Manage a list of substitution rules that GDB uses to rewrite the name
4113 of the directories where the sources are located. This can be useful
4114 for instance when the sources were moved to a different location
4115 between compilation and debugging.
4119 Print each CLI command as it is executed. Each command is prefixed with
4120 a number of `+' symbols representing the nesting depth.
4121 The source command now has a `-v' option to enable the same feature.
4125 The ARM Demon monitor support (RDP protocol, "target rdp").
4127 Kernel Object Display, an embedded debugging feature which only worked with
4128 an obsolete version of Cisco IOS.
4130 The 'set download-write-size' and 'show download-write-size' commands.
4132 * New remote packets
4135 Tell a stub about GDB client features, and request remote target features.
4136 The first feature implemented is PacketSize, which allows the target to
4137 specify the size of packets it can handle - to minimize the number of
4138 packets required and improve performance when connected to a remote
4142 Fetch an OS auxilliary vector from the remote stub. This packet is a
4143 more efficient replacement for qPart:auxv:read.
4145 qXfer:memory-map:read:
4146 Fetch a memory map from the remote stub, including information about
4147 RAM, ROM, and flash memory devices.
4152 Erase and program a flash memory device.
4154 * Removed remote packets
4157 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4158 used it, and only gdbserver implemented it.
4160 *** Changes in GDB 6.5
4164 Renesas M32C/M16C m32c-elf
4166 Morpho Technologies ms1 ms1-elf
4170 init-if-undefined Initialize a convenience variable, but
4171 only if it doesn't already have a value.
4173 The following commands are presently only implemented for native GNU/Linux:
4175 checkpoint Save a snapshot of the program state.
4177 restart <n> Return the program state to a
4178 previously saved state.
4180 info checkpoints List currently saved checkpoints.
4182 delete-checkpoint <n> Delete a previously saved checkpoint.
4184 set|show detach-on-fork Tell gdb whether to detach from a newly
4185 forked process, or to keep debugging it.
4187 info forks List forks of the user program that
4188 are available to be debugged.
4190 fork <n> Switch to debugging one of several
4191 forks of the user program that are
4192 available to be debugged.
4194 delete-fork <n> Delete a fork from the list of forks
4195 that are available to be debugged (and
4196 kill the forked process).
4198 detach-fork <n> Delete a fork from the list of forks
4199 that are available to be debugged (and
4200 allow the process to continue).
4204 Morpho Technologies ms2 ms1-elf
4206 * Improved Windows host support
4208 GDB now builds as a cross debugger hosted on i686-mingw32, including
4209 native console support, and remote communications using either
4210 network sockets or serial ports.
4212 * Improved Modula-2 language support
4214 GDB can now print most types in the Modula-2 syntax. This includes:
4215 basic types, set types, record types, enumerated types, range types,
4216 pointer types and ARRAY types. Procedure var parameters are correctly
4217 printed and hexadecimal addresses and character constants are also
4218 written in the Modula-2 syntax. Best results can be obtained by using
4219 GNU Modula-2 together with the -gdwarf-2 command line option.
4223 The ARM rdi-share module.
4225 The Netware NLM debug server.
4227 *** Changes in GDB 6.4
4229 * New native configurations
4231 OpenBSD/arm arm*-*-openbsd*
4232 OpenBSD/mips64 mips64-*-openbsd*
4236 Morpho Technologies ms1 ms1-elf
4238 * New command line options
4240 --batch-silent As for --batch, but totally silent.
4241 --return-child-result The debugger will exist with the same value
4242 the child (debugged) program exited with.
4243 --eval-command COMMAND, -ex COMMAND
4244 Execute a single GDB CLI command. This may be
4245 specified multiple times and in conjunction
4246 with the --command (-x) option.
4248 * Deprecated commands removed
4250 The following commands, that were deprecated in 2000, have been
4254 set|show arm disassembly-flavor set|show arm disassembler
4255 othernames set arm disassembler
4256 set|show remotedebug set|show debug remote
4257 set|show archdebug set|show debug arch
4258 set|show eventdebug set|show debug event
4261 * New BSD user-level threads support
4263 It is now possible to debug programs using the user-level threads
4264 library on OpenBSD and FreeBSD. Currently supported (target)
4267 FreeBSD/amd64 x86_64-*-freebsd*
4268 FreeBSD/i386 i386-*-freebsd*
4269 OpenBSD/i386 i386-*-openbsd*
4271 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4272 are not yet supported.
4274 * New support for Matsushita MN10300 w/sim added
4275 (Work in progress). mn10300-elf.
4277 * REMOVED configurations and files
4279 VxWorks and the XDR protocol *-*-vxworks
4280 Motorola MCORE mcore-*-*
4281 National Semiconductor NS32000 ns32k-*-*
4283 * New "set print array-indexes" command
4285 After turning this setting "on", GDB prints the index of each element
4286 when displaying arrays. The default is "off" to preserve the previous
4289 * VAX floating point support
4291 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4293 * User-defined command support
4295 In addition to using $arg0..$arg9 for argument passing, it is now possible
4296 to use $argc to determine now many arguments have been passed. See the
4297 section on user-defined commands in the user manual for more information.
4299 *** Changes in GDB 6.3:
4301 * New command line option
4303 GDB now accepts -l followed by a number to set the timeout for remote
4306 * GDB works with GCC -feliminate-dwarf2-dups
4308 GDB now supports a more compact representation of DWARF-2 debug
4309 information using DW_FORM_ref_addr references. These are produced
4310 by GCC with the option -feliminate-dwarf2-dups and also by some
4311 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4312 to use -feliminate-dwarf2-dups.
4314 * Internationalization
4316 When supported by the host system, GDB will be built with
4317 internationalization (libintl). The task of marking up the sources is
4318 continued, we're looking forward to our first translation.
4322 Initial support for debugging programs compiled with the GNAT
4323 implementation of the Ada programming language has been integrated
4324 into GDB. In this release, support is limited to expression evaluation.
4326 * New native configurations
4328 GNU/Linux/m32r m32r-*-linux-gnu
4332 GDB's remote protocol now includes support for the 'p' packet. This
4333 packet is used to fetch individual registers from a remote inferior.
4335 * END-OF-LIFE registers[] compatibility module
4337 GDB's internal register infrastructure has been completely rewritten.
4338 The new infrastructure making possible the implementation of key new
4339 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4342 GDB 6.3 will be the last release to include the the registers[]
4343 compatibility module that allowed out-of-date configurations to
4344 continue to work. This change directly impacts the following
4354 powerpc bdm protocol
4356 Unless there is activity to revive these configurations, they will be
4357 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4359 * OBSOLETE configurations and files
4361 Configurations that have been declared obsolete in this release have
4362 been commented out. Unless there is activity to revive these
4363 configurations, the next release of GDB will have their sources
4364 permanently REMOVED.
4373 *** Changes in GDB 6.2.1:
4375 * MIPS `break main; run' gave an heuristic-fence-post warning
4377 When attempting to run even a simple program, a warning about
4378 heuristic-fence-post being hit would be reported. This problem has
4381 * MIPS IRIX 'long double' crashed GDB
4383 When examining a long double variable, GDB would get a segmentation
4384 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4385 IRIX long double values).
4389 A bug in the VAX stack code was causing problems with the "next"
4390 command. This problem has been fixed.
4392 *** Changes in GDB 6.2:
4394 * Fix for ``many threads''
4396 On GNU/Linux systems that use the NPTL threads library, a program
4397 rapidly creating and deleting threads would confuse GDB leading to the
4400 ptrace: No such process.
4401 thread_db_get_info: cannot get thread info: generic error
4403 This problem has been fixed.
4405 * "-async" and "-noasync" options removed.
4407 Support for the broken "-noasync" option has been removed (it caused
4410 * New ``start'' command.
4412 This command runs the program until the begining of the main procedure.
4414 * New BSD Kernel Data Access Library (libkvm) interface
4416 Using ``target kvm'' it is now possible to debug kernel core dumps and
4417 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4418 platforms. Currently supported (native-only) configurations are:
4420 FreeBSD/amd64 x86_64-*-freebsd*
4421 FreeBSD/i386 i?86-*-freebsd*
4422 NetBSD/i386 i?86-*-netbsd*
4423 NetBSD/m68k m68*-*-netbsd*
4424 NetBSD/sparc sparc-*-netbsd*
4425 OpenBSD/amd64 x86_64-*-openbsd*
4426 OpenBSD/i386 i?86-*-openbsd*
4427 OpenBSD/m68k m68*-openbsd*
4428 OpenBSD/sparc sparc-*-openbsd*
4430 * Signal trampoline code overhauled
4432 Many generic problems with GDB's signal handling code have been fixed.
4433 These include: backtraces through non-contiguous stacks; recognition
4434 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4435 call; backtrace through a signal trampoline; step into and out of
4436 signal handlers; and single-stepping in the signal trampoline.
4438 Please note that kernel bugs are a limiting factor here. These
4439 features have been shown to work on an s390 GNU/Linux system that
4440 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4442 * Cygwin support for DWARF 2 added.
4444 * New native configurations
4446 GNU/Linux/hppa hppa*-*-linux*
4447 OpenBSD/hppa hppa*-*-openbsd*
4448 OpenBSD/m68k m68*-*-openbsd*
4449 OpenBSD/m88k m88*-*-openbsd*
4450 OpenBSD/powerpc powerpc-*-openbsd*
4451 NetBSD/vax vax-*-netbsd*
4452 OpenBSD/vax vax-*-openbsd*
4454 * END-OF-LIFE frame compatibility module
4456 GDB's internal frame infrastructure has been completely rewritten.
4457 The new infrastructure making it possible to support key new features
4458 including DWARF 2 Call Frame Information. To aid in the task of
4459 migrating old configurations to this new infrastructure, a
4460 compatibility module, that allowed old configurations to continue to
4461 work, was also included.
4463 GDB 6.2 will be the last release to include this frame compatibility
4464 module. This change directly impacts the following configurations:
4474 Unless there is activity to revive these configurations, they will be
4475 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4477 * REMOVED configurations and files
4479 Sun 3, running SunOS 3 m68*-*-sunos3*
4480 Sun 3, running SunOS 4 m68*-*-sunos4*
4481 Sun 2, running SunOS 3 m68000-*-sunos3*
4482 Sun 2, running SunOS 4 m68000-*-sunos4*
4483 Motorola 680x0 running LynxOS m68*-*-lynxos*
4484 AT&T 3b1/Unix pc m68*-att-*
4485 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4486 decstation mips-dec-* mips-little-*
4487 riscos mips-*-riscos* mips-*-sysv*
4488 sonymips mips-sony-*
4489 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4491 *** Changes in GDB 6.1.1:
4493 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4495 The TUI (Text-mode User Interface) is now built as part of a default
4496 GDB configuration. It is enabled by either selecting the TUI with the
4497 command line option "-i=tui" or by running the separate "gdbtui"
4498 program. For more information on the TUI, see the manual "Debugging
4501 * Pending breakpoint support (also included in GDB 6.1)
4503 Support has been added to allow you to specify breakpoints in shared
4504 libraries that have not yet been loaded. If a breakpoint location
4505 cannot be found, and the "breakpoint pending" option is set to auto,
4506 GDB queries you if you wish to make the breakpoint pending on a future
4507 shared-library load. If and when GDB resolves the breakpoint symbol,
4508 the pending breakpoint is removed as one or more regular breakpoints
4511 Pending breakpoints are very useful for GCJ Java debugging.
4513 * Fixed ISO-C build problems
4515 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4516 non ISO-C code that stopped them being built using a more strict ISO-C
4517 compiler (e.g., IBM's C compiler).
4519 * Fixed build problem on IRIX 5
4521 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4522 wasn't able to compile compile on an IRIX 5 system.
4524 * Added execute permission to gdb/gdbserver/configure
4526 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4527 permission. This bug would cause configure to fail on a number of
4528 systems (Solaris, IRIX). Ref: server/519.
4530 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4532 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4533 has been updated to use constant array sizes.
4535 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4537 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4538 its generated DWARF Call Frame Info. This encoding was causing GDB to
4539 panic, that panic has been fixed. Ref: gdb/1628.
4541 * Fixed a problem when examining parameters in shared library code.
4543 When examining parameters in optimized shared library code generated
4544 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4545 not available''. GDB now correctly displays the variable's value.
4547 *** Changes in GDB 6.1:
4549 * Removed --with-mmalloc
4551 Support for the mmalloc memory manager has been removed, as it
4552 conflicted with the internal gdb byte cache.
4554 * Changes in AMD64 configurations
4556 The AMD64 target now includes the %cs and %ss registers. As a result
4557 the AMD64 remote protocol has changed; this affects the floating-point
4558 and SSE registers. If you rely on those registers for your debugging,
4559 you should upgrade gdbserver on the remote side.
4561 * Revised SPARC target
4563 The SPARC target has been completely revised, incorporating the
4564 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4565 support for LynxOS and SunOS 4 has been dropped. Calling functions
4566 from within GDB on operating systems with a non-executable stack
4567 (Solaris, OpenBSD) now works.
4571 GDB has a new C++ demangler which does a better job on the mangled
4572 names generated by current versions of g++. It also runs faster, so
4573 with this and other changes gdb should now start faster on large C++
4576 * DWARF 2 Location Expressions
4578 GDB support for location expressions has been extended to support function
4579 arguments and frame bases. Older versions of GDB could crash when they
4582 * C++ nested types and namespaces
4584 GDB's support for nested types and namespaces in C++ has been
4585 improved, especially if you use the DWARF 2 debugging format. (This
4586 is the default for recent versions of GCC on most platforms.)
4587 Specifically, if you have a class "Inner" defined within a class or
4588 namespace "Outer", then GDB realizes that the class's name is
4589 "Outer::Inner", not simply "Inner". This should greatly reduce the
4590 frequency of complaints about not finding RTTI symbols. In addition,
4591 if you are stopped at inside of a function defined within a namespace,
4592 GDB modifies its name lookup accordingly.
4594 * New native configurations
4596 NetBSD/amd64 x86_64-*-netbsd*
4597 OpenBSD/amd64 x86_64-*-openbsd*
4598 OpenBSD/alpha alpha*-*-openbsd*
4599 OpenBSD/sparc sparc-*-openbsd*
4600 OpenBSD/sparc64 sparc64-*-openbsd*
4602 * New debugging protocols
4604 M32R with SDI protocol m32r-*-elf*
4606 * "set prompt-escape-char" command deleted.
4608 The command "set prompt-escape-char" has been deleted. This command,
4609 and its very obscure effet on GDB's prompt, was never documented,
4610 tested, nor mentioned in the NEWS file.
4612 * OBSOLETE configurations and files
4614 Configurations that have been declared obsolete in this release have
4615 been commented out. Unless there is activity to revive these
4616 configurations, the next release of GDB will have their sources
4617 permanently REMOVED.
4619 Sun 3, running SunOS 3 m68*-*-sunos3*
4620 Sun 3, running SunOS 4 m68*-*-sunos4*
4621 Sun 2, running SunOS 3 m68000-*-sunos3*
4622 Sun 2, running SunOS 4 m68000-*-sunos4*
4623 Motorola 680x0 running LynxOS m68*-*-lynxos*
4624 AT&T 3b1/Unix pc m68*-att-*
4625 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4626 decstation mips-dec-* mips-little-*
4627 riscos mips-*-riscos* mips-*-sysv*
4628 sonymips mips-sony-*
4629 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4631 * REMOVED configurations and files
4633 SGI Irix-4.x mips-sgi-irix4 or iris4
4634 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4635 Z8000 simulator z8k-zilog-none or z8ksim
4636 Matsushita MN10200 w/simulator mn10200-*-*
4637 H8/500 simulator h8500-hitachi-hms or h8500hms
4638 HP/PA running BSD hppa*-*-bsd*
4639 HP/PA running OSF/1 hppa*-*-osf*
4640 HP/PA Pro target hppa*-*-pro*
4641 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4642 386BSD i[3456]86-*-bsd*
4643 Sequent family i[3456]86-sequent-sysv4*
4644 i[3456]86-sequent-sysv*
4645 i[3456]86-sequent-bsd*
4646 SPARC running LynxOS sparc-*-lynxos*
4647 SPARC running SunOS 4 sparc-*-sunos4*
4648 Tsqware Sparclet sparclet-*-*
4649 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4651 *** Changes in GDB 6.0:
4655 Support for debugging the Objective-C programming language has been
4656 integrated into GDB.
4658 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4660 DWARF 2's Call Frame Information makes available compiler generated
4661 information that more exactly describes the program's run-time stack.
4662 By using this information, GDB is able to provide more robust stack
4665 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4666 have been updated to use a new backtrace mechanism which includes
4667 DWARF 2 CFI support.
4671 GDB's remote protocol has been extended to include support for hosted
4672 file I/O (where the remote target uses GDB's file system). See GDB's
4673 remote protocol documentation for details.
4675 * All targets using the new architecture framework.
4677 All of GDB's targets have been updated to use the new internal
4678 architecture framework. The way is now open for future GDB releases
4679 to include cross-architecture native debugging support (i386 on amd64,
4682 * GNU/Linux's Thread Local Storage (TLS)
4684 GDB now includes support for for the GNU/Linux implementation of
4685 per-thread variables.
4687 * GNU/Linux's Native POSIX Thread Library (NPTL)
4689 GDB's thread code has been updated to work with either the new
4690 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4692 * Separate debug info.
4694 GDB, in conjunction with BINUTILS, now supports a mechanism for
4695 automatically loading debug information from a separate file. Instead
4696 of shipping full debug and non-debug versions of system libraries,
4697 system integrators can now instead ship just the stripped libraries
4698 and optional debug files.
4700 * DWARF 2 Location Expressions
4702 DWARF 2 Location Expressions allow the compiler to more completely
4703 describe the location of variables (even in optimized code) to the
4706 GDB now includes preliminary support for location expressions (support
4707 for DW_OP_piece is still missing).
4711 A number of long standing bugs that caused GDB to die while starting a
4712 Java application have been fixed. GDB's Java support is now
4713 considered "useable".
4715 * GNU/Linux support for fork, vfork, and exec.
4717 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4718 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4721 * GDB supports logging output to a file
4723 There are two new commands, "set logging" and "show logging", which can be
4724 used to capture GDB's output to a file.
4726 * The meaning of "detach" has changed for gdbserver
4728 The "detach" command will now resume the application, as documented. To
4729 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4732 * d10v, m68hc11 `regs' command deprecated
4734 The `info registers' command has been updated so that it displays the
4735 registers using a format identical to the old `regs' command.
4739 A new command, "maint set profile on/off", has been added. This command can
4740 be used to enable or disable profiling while running GDB, to profile a
4741 session or a set of commands. In addition there is a new configure switch,
4742 "--enable-profiling", which will cause GDB to be compiled with profiling
4743 data, for more informative profiling results.
4745 * Default MI syntax changed to "mi2".
4747 The default MI (machine interface) syntax, enabled by the command line
4748 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4749 "mi1", can be enabled by specifying the option "-i=mi1".
4751 Support for the original "mi0" syntax (included in GDB 5.0) has been
4754 Fix for gdb/192: removed extraneous space when displaying frame level.
4755 Fix for gdb/672: update changelist is now output in mi list format.
4756 Fix for gdb/702: a -var-assign that updates the value now shows up
4757 in a subsequent -var-update.
4759 * New native configurations.
4761 FreeBSD/amd64 x86_64-*-freebsd*
4763 * Multi-arched targets.
4765 HP/PA HPUX11 hppa*-*-hpux*
4766 Renesas M32R/D w/simulator m32r-*-elf*
4768 * OBSOLETE configurations and files
4770 Configurations that have been declared obsolete in this release have
4771 been commented out. Unless there is activity to revive these
4772 configurations, the next release of GDB will have their sources
4773 permanently REMOVED.
4775 Z8000 simulator z8k-zilog-none or z8ksim
4776 Matsushita MN10200 w/simulator mn10200-*-*
4777 H8/500 simulator h8500-hitachi-hms or h8500hms
4778 HP/PA running BSD hppa*-*-bsd*
4779 HP/PA running OSF/1 hppa*-*-osf*
4780 HP/PA Pro target hppa*-*-pro*
4781 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4782 Sequent family i[3456]86-sequent-sysv4*
4783 i[3456]86-sequent-sysv*
4784 i[3456]86-sequent-bsd*
4785 Tsqware Sparclet sparclet-*-*
4786 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4788 * REMOVED configurations and files
4791 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4792 IBM AIX PS/2 i[3456]86-*-aix
4793 i386 running Mach 3.0 i[3456]86-*-mach3*
4794 i386 running Mach i[3456]86-*-mach*
4795 i386 running OSF/1 i[3456]86-*osf1mk*
4796 HP/Apollo 68k Family m68*-apollo*-sysv*,
4798 m68*-hp-bsd*, m68*-hp-hpux*
4799 Argonaut Risc Chip (ARC) arc-*-*
4800 Mitsubishi D30V d30v-*-*
4801 Fujitsu FR30 fr30-*-elf*
4802 OS/9000 i[34]86-*-os9k
4803 I960 with MON960 i960-*-coff
4805 * MIPS $fp behavior changed
4807 The convenience variable $fp, for the MIPS, now consistently returns
4808 the address of the current frame's base. Previously, depending on the
4809 context, $fp could refer to either $sp or the current frame's base
4810 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4811 The GNU Source-Level Debugger''.
4813 *** Changes in GDB 5.3:
4815 * GNU/Linux shared library multi-threaded performance improved.
4817 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4818 `/proc', in preference to `ptrace' for memory reads. This may result
4819 in an improvement in the start-up time of multi-threaded, shared
4820 library applications when run under GDB. One GDB user writes: ``loads
4821 shared libs like mad''.
4823 * ``gdbserver'' now supports multi-threaded applications on some targets
4825 Support for debugging multi-threaded applications which use
4826 the GNU/Linux LinuxThreads package has been added for
4827 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4828 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4830 * GDB now supports C/C++ preprocessor macros.
4832 GDB now expands preprocessor macro invocations in C/C++ expressions,
4833 and provides various commands for showing macro definitions and how
4836 The new command `macro expand EXPRESSION' expands any macro
4837 invocations in expression, and shows the result.
4839 The new command `show macro MACRO-NAME' shows the definition of the
4840 macro named MACRO-NAME, and where it was defined.
4842 Most compilers don't include information about macros in the debugging
4843 information by default. In GCC 3.1, for example, you need to compile
4844 your program with the options `-gdwarf-2 -g3'. If the macro
4845 information is present in the executable, GDB will read it.
4847 * Multi-arched targets.
4849 DEC Alpha (partial) alpha*-*-*
4850 DEC VAX (partial) vax-*-*
4852 National Semiconductor NS32000 (partial) ns32k-*-*
4853 Motorola 68000 (partial) m68k-*-*
4854 Motorola MCORE mcore-*-*
4858 Fujitsu FRV architecture added by Red Hat frv*-*-*
4861 * New native configurations
4863 Alpha NetBSD alpha*-*-netbsd*
4864 SH NetBSD sh*-*-netbsdelf*
4865 MIPS NetBSD mips*-*-netbsd*
4866 UltraSPARC NetBSD sparc64-*-netbsd*
4868 * OBSOLETE configurations and files
4870 Configurations that have been declared obsolete in this release have
4871 been commented out. Unless there is activity to revive these
4872 configurations, the next release of GDB will have their sources
4873 permanently REMOVED.
4875 Mitsubishi D30V d30v-*-*
4876 OS/9000 i[34]86-*-os9k
4877 IBM AIX PS/2 i[3456]86-*-aix
4878 Fujitsu FR30 fr30-*-elf*
4879 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4880 Argonaut Risc Chip (ARC) arc-*-*
4881 i386 running Mach 3.0 i[3456]86-*-mach3*
4882 i386 running Mach i[3456]86-*-mach*
4883 i386 running OSF/1 i[3456]86-*osf1mk*
4884 HP/Apollo 68k Family m68*-apollo*-sysv*,
4886 m68*-hp-bsd*, m68*-hp-hpux*
4887 I960 with MON960 i960-*-coff
4889 * OBSOLETE languages
4891 CHILL, a Pascal like language used by telecommunications companies.
4893 * REMOVED configurations and files
4895 AMD 29k family via UDI a29k-amd-udi, udi29k
4896 A29K VxWorks a29k-*-vxworks
4897 AMD 29000 embedded, using EBMON a29k-none-none
4898 AMD 29000 embedded with COFF a29k-none-coff
4899 AMD 29000 embedded with a.out a29k-none-aout
4901 testsuite/gdb.hp/gdb.threads-hp/ directory
4903 * New command "set max-user-call-depth <nnn>"
4905 This command allows the user to limit the call depth of user-defined
4906 commands. The default is 1024.
4908 * Changes in FreeBSD/i386 native debugging.
4910 Support for the "generate-core-file" has been added.
4912 * New commands "dump", "append", and "restore".
4914 These commands allow data to be copied from target memory
4915 to a bfd-format or binary file (dump and append), and back
4916 from a file into memory (restore).
4918 * Improved "next/step" support on multi-processor Alpha Tru64.
4920 The previous single-step mechanism could cause unpredictable problems,
4921 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4922 of a software single-step mechanism prevents this.
4924 *** Changes in GDB 5.2.1:
4932 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4933 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4934 Fix, by Joel Brobecker imported from mainline.
4936 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4937 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4938 Fix, by Fred Fish, imported from mainline.
4940 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4941 Surprisingly enough, it works now.
4942 By Michal Ludvig, imported from mainline.
4944 i386 hardware watchpoint support:
4945 avoid misses on second run for some targets.
4946 By Pierre Muller, imported from mainline.
4948 *** Changes in GDB 5.2:
4950 * New command "set trust-readonly-sections on[off]".
4952 This command is a hint that tells gdb that read-only sections
4953 really are read-only (ie. that their contents will not change).
4954 In this mode, gdb will go to the object file rather than the
4955 target to read memory from read-only sections (such as ".text").
4956 This can be a significant performance improvement on some
4957 (notably embedded) targets.
4959 * New command "generate-core-file" (or "gcore").
4961 This new gdb command allows the user to drop a core file of the child
4962 process state at any time. So far it's been implemented only for
4963 GNU/Linux and Solaris, but should be relatively easily ported to other
4964 hosts. Argument is core file name (defaults to core.<pid>).
4966 * New command line option
4968 GDB now accepts --pid or -p followed by a process id.
4970 * Change in command line behavior -- corefiles vs. process ids.
4972 There is a subtle behavior in the way in which GDB handles
4973 command line arguments. The first non-flag argument is always
4974 a program to debug, but the second non-flag argument may either
4975 be a corefile or a process id. Previously, GDB would attempt to
4976 open the second argument as a corefile, and if that failed, would
4977 issue a superfluous error message and then attempt to attach it as
4978 a process. Now, if the second argument begins with a non-digit,
4979 it will be treated as a corefile. If it begins with a digit,
4980 GDB will attempt to attach it as a process, and if no such process
4981 is found, will then attempt to open it as a corefile.
4983 * Changes in ARM configurations.
4985 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4986 configuration is fully multi-arch.
4988 * New native configurations
4990 ARM NetBSD arm*-*-netbsd*
4991 x86 OpenBSD i[3456]86-*-openbsd*
4992 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4993 Sparc64 running FreeBSD sparc64-*-freebsd*
4997 Sanyo XStormy16 xstormy16-elf
4999 * OBSOLETE configurations and files
5001 Configurations that have been declared obsolete in this release have
5002 been commented out. Unless there is activity to revive these
5003 configurations, the next release of GDB will have their sources
5004 permanently REMOVED.
5006 AMD 29k family via UDI a29k-amd-udi, udi29k
5007 A29K VxWorks a29k-*-vxworks
5008 AMD 29000 embedded, using EBMON a29k-none-none
5009 AMD 29000 embedded with COFF a29k-none-coff
5010 AMD 29000 embedded with a.out a29k-none-aout
5012 testsuite/gdb.hp/gdb.threads-hp/ directory
5014 * REMOVED configurations and files
5016 TI TMS320C80 tic80-*-*
5018 PowerPC Solaris powerpcle-*-solaris*
5019 PowerPC Windows NT powerpcle-*-cygwin32
5020 PowerPC Netware powerpc-*-netware*
5021 Harris/CXUX m88k m88*-harris-cxux*
5022 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5023 ns32k-utek-sysv* ns32k-utek-*
5024 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5025 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5026 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5027 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5028 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5030 * Changes to command line processing
5032 The new `--args' feature can be used to specify command-line arguments
5033 for the inferior from gdb's command line.
5035 * Changes to key bindings
5037 There is a new `operate-and-get-next' function bound to `C-o'.
5039 *** Changes in GDB 5.1.1
5041 Fix compile problem on DJGPP.
5043 Fix a problem with floating-point registers on the i386 being
5046 Fix to stop GDB crashing on .debug_str debug info.
5048 Numerous documentation fixes.
5050 Numerous testsuite fixes.
5052 *** Changes in GDB 5.1:
5054 * New native configurations
5056 Alpha FreeBSD alpha*-*-freebsd*
5057 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5058 MIPS GNU/Linux mips*-*-linux*
5059 MIPS SGI Irix 6.x mips*-sgi-irix6*
5060 ia64 AIX ia64-*-aix*
5061 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5065 Motorola 68HC11 and 68HC12 m68hc11-elf
5067 UltraSparc running GNU/Linux sparc64-*-linux*
5069 * OBSOLETE configurations and files
5071 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5072 Harris/CXUX m88k m88*-harris-cxux*
5073 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5074 ns32k-utek-sysv* ns32k-utek-*
5075 TI TMS320C80 tic80-*-*
5077 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5078 PowerPC Solaris powerpcle-*-solaris*
5079 PowerPC Windows NT powerpcle-*-cygwin32
5080 PowerPC Netware powerpc-*-netware*
5081 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5082 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5083 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5084 Apple Macintosh (MPW) host N/A
5086 stuff.c (Program to stuff files into a specially prepared space in kdb)
5087 kdb-start.c (Main loop for the standalone kernel debugger)
5089 Configurations that have been declared obsolete in this release have
5090 been commented out. Unless there is activity to revive these
5091 configurations, the next release of GDB will have their sources
5092 permanently REMOVED.
5094 * REMOVED configurations and files
5096 Altos 3068 m68*-altos-*
5097 Convex c1-*-*, c2-*-*
5099 ARM RISCix arm-*-* (as host)
5103 * GDB has been converted to ISO C.
5105 GDB's source code has been converted to ISO C. In particular, the
5106 sources are fully protoized, and rely on standard headers being
5111 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5113 * The MI enabled by default.
5115 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5116 revised and enabled by default. Packages which use GDB as a debugging
5117 engine behind a UI or another front end are encouraged to switch to
5118 using the GDB/MI interface, instead of the old annotations interface
5119 which is now deprecated.
5121 * Support for debugging Pascal programs.
5123 GDB now includes support for debugging Pascal programs. The following
5124 main features are supported:
5126 - Pascal-specific data types such as sets;
5128 - automatic recognition of Pascal sources based on file-name
5131 - Pascal-style display of data types, variables, and functions;
5133 - a Pascal expression parser.
5135 However, some important features are not yet supported.
5137 - Pascal string operations are not supported at all;
5139 - there are some problems with boolean types;
5141 - Pascal type hexadecimal constants are not supported
5142 because they conflict with the internal variables format;
5144 - support for Pascal objects and classes is not full yet;
5146 - unlike Pascal, GDB is case-sensitive for symbol names.
5148 * Changes in completion.
5150 Commands such as `shell', `run' and `set args', which pass arguments
5151 to inferior programs, now complete on file names, similar to what
5152 users expect at the shell prompt.
5154 Commands which accept locations, such as `disassemble', `print',
5155 `breakpoint', `until', etc. now complete on filenames as well as
5156 program symbols. Thus, if you type "break foob TAB", and the source
5157 files linked into the programs include `foobar.c', that file name will
5158 be one of the candidates for completion. However, file names are not
5159 considered for completion after you typed a colon that delimits a file
5160 name from a name of a function in that file, as in "break foo.c:bar".
5162 `set demangle-style' completes on available demangling styles.
5164 * New platform-independent commands:
5166 It is now possible to define a post-hook for a command as well as a
5167 hook that runs before the command. For more details, see the
5168 documentation of `hookpost' in the GDB manual.
5170 * Changes in GNU/Linux native debugging.
5172 Support for debugging multi-threaded programs has been completely
5173 revised for all platforms except m68k and sparc. You can now debug as
5174 many threads as your system allows you to have.
5176 Attach/detach is supported for multi-threaded programs.
5178 Support for SSE registers was added for x86. This doesn't work for
5179 multi-threaded programs though.
5181 * Changes in MIPS configurations.
5183 Multi-arch support is enabled for all MIPS configurations.
5185 GDB can now be built as native debugger on SGI Irix 6.x systems for
5186 debugging n32 executables. (Debugging 64-bit executables is not yet
5189 * Unified support for hardware watchpoints in all x86 configurations.
5191 Most (if not all) native x86 configurations support hardware-assisted
5192 breakpoints and watchpoints in a unified manner. This support
5193 implements debug register sharing between watchpoints, which allows to
5194 put a virtually infinite number of watchpoints on the same address,
5195 and also supports watching regions up to 16 bytes with several debug
5198 The new maintenance command `maintenance show-debug-regs' toggles
5199 debugging print-outs in functions that insert, remove, and test
5200 watchpoints and hardware breakpoints.
5202 * Changes in the DJGPP native configuration.
5204 New command ``info dos sysinfo'' displays assorted information about
5205 the CPU, OS, memory, and DPMI server.
5207 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5208 display information about segment descriptors stored in GDT, LDT, and
5211 New commands ``info dos pde'' and ``info dos pte'' display entries
5212 from Page Directory and Page Tables (for now works with CWSDPMI only).
5213 New command ``info dos address-pte'' displays the Page Table entry for
5214 a given linear address.
5216 GDB can now pass command lines longer than 126 characters to the
5217 program being debugged (requires an update to the libdbg.a library
5218 which is part of the DJGPP development kit).
5220 DWARF2 debug info is now supported.
5222 It is now possible to `step' and `next' through calls to `longjmp'.
5224 * Changes in documentation.
5226 All GDB documentation was converted to GFDL, the GNU Free
5227 Documentation License.
5229 Tracepoints-related commands are now fully documented in the GDB
5232 TUI, the Text-mode User Interface, is now documented in the manual.
5234 Tracepoints-related commands are now fully documented in the GDB
5237 The "GDB Internals" manual now has an index. It also includes
5238 documentation of `ui_out' functions, GDB coding standards, x86
5239 hardware watchpoints, and memory region attributes.
5241 * GDB's version number moved to ``version.in''
5243 The Makefile variable VERSION has been replaced by the file
5244 ``version.in''. People creating GDB distributions should update the
5245 contents of this file.
5249 GUD support is now a standard part of the EMACS distribution.
5251 *** Changes in GDB 5.0:
5253 * Improved support for debugging FP programs on x86 targets
5255 Unified and much-improved support for debugging floating-point
5256 programs on all x86 targets. In particular, ``info float'' now
5257 displays the FP registers in the same format on all x86 targets, with
5258 greater level of detail.
5260 * Improvements and bugfixes in hardware-assisted watchpoints
5262 It is now possible to watch array elements, struct members, and
5263 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5264 on x86 targets no longer erroneously trigger when the address is
5267 * Improvements in the native DJGPP version of GDB
5269 The distribution now includes all the scripts and auxiliary files
5270 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5271 machines ``out of the box''.
5273 The DJGPP version can now debug programs that use signals. It is
5274 possible to catch signals that happened in the debuggee, deliver
5275 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5276 would kill the program being debugged.) Programs that hook hardware
5277 interrupts (keyboard, timer, etc.) can also be debugged.
5279 It is now possible to debug DJGPP programs that redirect their
5280 standard handles or switch them to raw (as opposed to cooked) mode, or
5281 even close them. The command ``run < foo > bar'' works as expected,
5282 and ``info terminal'' reports useful information about the debuggee's
5283 terminal, including raw/cooked mode, redirection, etc.
5285 The DJGPP version now uses termios functions for console I/O, which
5286 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5289 DOS-style file names with drive letters are now fully supported by
5292 It is now possible to debug DJGPP programs that switch their working
5293 directory. It is also possible to rerun the debuggee any number of
5294 times without restarting GDB; thus, you can use the same setup,
5295 breakpoints, etc. for many debugging sessions.
5297 * New native configurations
5299 ARM GNU/Linux arm*-*-linux*
5300 PowerPC GNU/Linux powerpc-*-linux*
5304 Motorola MCore mcore-*-*
5305 x86 VxWorks i[3456]86-*-vxworks*
5306 PowerPC VxWorks powerpc-*-vxworks*
5307 TI TMS320C80 tic80-*-*
5309 * OBSOLETE configurations
5311 Altos 3068 m68*-altos-*
5312 Convex c1-*-*, c2-*-*
5314 ARM RISCix arm-*-* (as host)
5317 Configurations that have been declared obsolete will be commented out,
5318 but the code will be left in place. If there is no activity to revive
5319 these configurations before the next release of GDB, the sources will
5320 be permanently REMOVED.
5322 * Gould support removed
5324 Support for the Gould PowerNode and NP1 has been removed.
5326 * New features for SVR4
5328 On SVR4 native platforms (such as Solaris), if you attach to a process
5329 without first loading a symbol file, GDB will now attempt to locate and
5330 load symbols from the running process's executable file.
5332 * Many C++ enhancements
5334 C++ support has been greatly improved. Overload resolution now works properly
5335 in almost all cases. RTTI support is on the way.
5337 * Remote targets can connect to a sub-program
5339 A popen(3) style serial-device has been added. This device starts a
5340 sub-process (such as a stand-alone simulator) and then communicates
5341 with that. The sub-program to run is specified using the syntax
5342 ``|<program> <args>'' vis:
5344 (gdb) set remotedebug 1
5345 (gdb) target extended-remote |mn10300-elf-sim program-args
5347 * MIPS 64 remote protocol
5349 A long standing bug in the mips64 remote protocol where by GDB
5350 expected certain 32 bit registers (ex SR) to be transfered as 32
5351 instead of 64 bits has been fixed.
5353 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5354 added to provide backward compatibility with older versions of GDB.
5356 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5358 The command ``set remotebinarydownload'' command has been replaced by
5359 ``set remote X-packet''. Other commands in ``set remote'' family
5360 include ``set remote P-packet''.
5362 * Breakpoint commands accept ranges.
5364 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5365 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5366 ``tracepoint passcount'' also accepts a range of tracepoints.
5368 * ``apropos'' command added.
5370 The ``apropos'' command searches through command names and
5371 documentation strings, printing out matches, making it much easier to
5372 try to find a command that does what you are looking for.
5376 A new machine oriented interface (MI) has been added to GDB. This
5377 interface is designed for debug environments running GDB as a separate
5378 process. This is part of the long term libGDB project. See the
5379 "GDB/MI" chapter of the GDB manual for further information. It can be
5380 enabled by configuring with:
5382 .../configure --enable-gdbmi
5384 *** Changes in GDB-4.18:
5386 * New native configurations
5388 HP-UX 10.20 hppa*-*-hpux10.20
5389 HP-UX 11.x hppa*-*-hpux11.0*
5390 M68K GNU/Linux m68*-*-linux*
5394 Fujitsu FR30 fr30-*-elf*
5395 Intel StrongARM strongarm-*-*
5396 Mitsubishi D30V d30v-*-*
5398 * OBSOLETE configurations
5400 Gould PowerNode, NP1 np1-*-*, pn-*-*
5402 Configurations that have been declared obsolete will be commented out,
5403 but the code will be left in place. If there is no activity to revive
5404 these configurations before the next release of GDB, the sources will
5405 be permanently REMOVED.
5409 As a compatibility experiment, GDB's source files buildsym.h and
5410 buildsym.c have been converted to pure standard C, no longer
5411 containing any K&R compatibility code. We believe that all systems in
5412 use today either come with a standard C compiler, or have a GCC port
5413 available. If this is not true, please report the affected
5414 configuration to bug-gdb@gnu.org immediately. See the README file for
5415 information about getting a standard C compiler if you don't have one
5420 GDB now uses readline 2.2.
5422 * set extension-language
5424 You can now control the mapping between filename extensions and source
5425 languages by using the `set extension-language' command. For instance,
5426 you can ask GDB to treat .c files as C++ by saying
5427 set extension-language .c c++
5428 The command `info extensions' lists all of the recognized extensions
5429 and their associated languages.
5431 * Setting processor type for PowerPC and RS/6000
5433 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5434 you can use the `set processor' command to specify what variant of the
5435 PowerPC family you are debugging. The command
5439 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5440 following PowerPC and RS6000 variants:
5442 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5443 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5445 403GC IBM PowerPC 403GC
5446 505 Motorola PowerPC 505
5447 860 Motorola PowerPC 860 or 850
5448 601 Motorola PowerPC 601
5449 602 Motorola PowerPC 602
5450 603 Motorola/IBM PowerPC 603 or 603e
5451 604 Motorola PowerPC 604 or 604e
5452 750 Motorola/IBM PowerPC 750 or 750
5454 At the moment, this command just tells GDB what to name the
5455 special-purpose processor registers. Since almost all the affected
5456 registers are inaccessible to user-level programs, this command is
5457 only useful for remote debugging in its present form.
5461 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5462 more extensive support for HP-UX. Added features include shared
5463 library support, kernel threads and hardware watchpoints for 11.00,
5464 support for HP's ANSI C and C++ compilers, and a compatibility mode
5465 for xdb and dbx commands.
5469 HP's donation includes the new concept of catchpoints, which is a
5470 generalization of the old catch command. On HP-UX, it is now possible
5471 to catch exec, fork, and vfork, as well as library loading.
5473 This means that the existing catch command has changed; its first
5474 argument now specifies the type of catch to be set up. See the
5475 output of "help catch" for a list of catchpoint types.
5477 * Debugging across forks
5479 On HP-UX, you can choose which process to debug when a fork() happens
5484 HP has donated a curses-based terminal user interface (TUI). To get
5485 it, build with --enable-tui. Although this can be enabled for any
5486 configuration, at present it only works for native HP debugging.
5488 * GDB remote protocol additions
5490 A new protocol packet 'X' that writes binary data is now available.
5491 Default behavior is to try 'X', then drop back to 'M' if the stub
5492 fails to respond. The settable variable `remotebinarydownload'
5493 allows explicit control over the use of 'X'.
5495 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5496 full 64-bit address. The command
5498 set remoteaddresssize 32
5500 can be used to revert to the old behaviour. For existing remote stubs
5501 the change should not be noticed, as the additional address information
5504 In order to assist in debugging stubs, you may use the maintenance
5505 command `packet' to send any text string to the stub. For instance,
5507 maint packet heythere
5509 sends the packet "$heythere#<checksum>". Note that it is very easy to
5510 disrupt a debugging session by sending the wrong packet at the wrong
5513 The compare-sections command allows you to compare section data on the
5514 target to what is in the executable file without uploading or
5515 downloading, by comparing CRC checksums.
5517 * Tracing can collect general expressions
5519 You may now collect general expressions at tracepoints. This requires
5520 further additions to the target-side stub; see tracepoint.c and
5521 doc/agentexpr.texi for further details.
5523 * mask-address variable for Mips
5525 For Mips targets, you may control the zeroing of the upper 32 bits of
5526 a 64-bit address by entering `set mask-address on'. This is mainly
5527 of interest to users of embedded R4xxx and R5xxx processors.
5529 * Higher serial baud rates
5531 GDB's serial code now allows you to specify baud rates 57600, 115200,
5532 230400, and 460800 baud. (Note that your host system may not be able
5533 to achieve all of these rates.)
5537 The i960 configuration now includes an initial implementation of a
5538 builtin simulator, contributed by Jim Wilson.
5541 *** Changes in GDB-4.17:
5543 * New native configurations
5545 Alpha GNU/Linux alpha*-*-linux*
5546 Unixware 2.x i[3456]86-unixware2*
5547 Irix 6.x mips*-sgi-irix6*
5548 PowerPC GNU/Linux powerpc-*-linux*
5549 PowerPC Solaris powerpcle-*-solaris*
5550 Sparc GNU/Linux sparc-*-linux*
5551 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5555 Argonaut Risc Chip (ARC) arc-*-*
5556 Hitachi H8/300S h8300*-*-*
5557 Matsushita MN10200 w/simulator mn10200-*-*
5558 Matsushita MN10300 w/simulator mn10300-*-*
5559 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5560 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5561 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5562 Mitsubishi D10V w/simulator d10v-*-*
5563 Mitsubishi M32R/D w/simulator m32r-*-elf*
5564 Tsqware Sparclet sparclet-*-*
5565 NEC V850 w/simulator v850-*-*
5567 * New debugging protocols
5569 ARM with RDI protocol arm*-*-*
5570 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5571 DDB and LSI variants of PMON protocol mips*-*-*
5572 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5573 PowerPC with SDS protocol powerpc{,le}-*-eabi
5574 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5578 All configurations can now understand and use the DWARF 2 debugging
5579 format. The choice is automatic, if the symbol file contains DWARF 2
5584 GDB now includes basic Java language support. This support is
5585 only useful with Java compilers that produce native machine code.
5587 * solib-absolute-prefix and solib-search-path
5589 For SunOS and SVR4 shared libraries, you may now set the prefix for
5590 loading absolute shared library symbol files, and the search path for
5591 locating non-absolute shared library symbol files.
5593 * Live range splitting
5595 GDB can now effectively debug code for which GCC has performed live
5596 range splitting as part of its optimization. See gdb/doc/LRS for
5597 more details on the expected format of the stabs information.
5601 GDB's support for the GNU Hurd, including thread debugging, has been
5602 updated to work with current versions of the Hurd.
5606 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5607 instruction set. ARM GDB automatically detects when Thumb
5608 instructions are in use, and adjusts disassembly and backtracing
5613 GDB's MIPS target configurations now handle the MIP16 16-bit
5618 GDB now includes support for overlays; if an executable has been
5619 linked such that multiple sections are based at the same address, GDB
5620 will decide which section to use for symbolic info. You can choose to
5621 control the decision manually, using overlay commands, or implement
5622 additional target-side support and use "overlay load-target" to bring
5623 in the overlay mapping. Do "help overlay" for more detail.
5627 The command "info symbol <address>" displays information about
5628 the symbol at the specified address.
5632 The standard remote protocol now includes an extension that allows
5633 asynchronous collection and display of trace data. This requires
5634 extensive support in the target-side debugging stub. Tracing mode
5635 includes a new interaction mode in GDB and new commands: see the
5636 file tracepoint.c for more details.
5640 Configurations for embedded MIPS now include a simulator contributed
5641 by Cygnus Solutions. The simulator supports the instruction sets
5642 of most MIPS variants.
5646 Sparc configurations may now include the ERC32 simulator contributed
5647 by the European Space Agency. The simulator is not built into
5648 Sparc targets by default; configure with --enable-sim to include it.
5652 For target configurations that may include multiple variants of a
5653 basic architecture (such as MIPS and SH), you may now set the
5654 architecture explicitly. "set arch" sets, "info arch" lists
5655 the possible architectures.
5657 *** Changes in GDB-4.16:
5659 * New native configurations
5661 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5662 M68K NetBSD m68k-*-netbsd*
5663 PowerPC AIX 4.x powerpc-*-aix*
5664 PowerPC MacOS powerpc-*-macos*
5665 PowerPC Windows NT powerpcle-*-cygwin32
5666 RS/6000 AIX 4.x rs6000-*-aix4*
5670 ARM with RDP protocol arm-*-*
5671 I960 with MON960 i960-*-coff
5672 MIPS VxWorks mips*-*-vxworks*
5673 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5674 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5676 Matra Sparclet sparclet-*-*
5680 The powerpc-eabi configuration now includes the PSIM simulator,
5681 contributed by Andrew Cagney, with assistance from Mike Meissner.
5682 PSIM is a very elaborate model of the PowerPC, including not only
5683 basic instruction set execution, but also details of execution unit
5684 performance and I/O hardware. See sim/ppc/README for more details.
5688 GDB now works with Solaris 2.5.
5690 * Windows 95/NT native
5692 GDB will now work as a native debugger on Windows 95 and Windows NT.
5693 To build it from source, you must use the "gnu-win32" environment,
5694 which uses a DLL to emulate enough of Unix to run the GNU tools.
5695 Further information, binaries, and sources are available at
5696 ftp.cygnus.com, under pub/gnu-win32.
5698 * dont-repeat command
5700 If a user-defined command includes the command `dont-repeat', then the
5701 command will not be repeated if the user just types return. This is
5702 useful if the command is time-consuming to run, so that accidental
5703 extra keystrokes don't run the same command many times.
5705 * Send break instead of ^C
5707 The standard remote protocol now includes an option to send a break
5708 rather than a ^C to the target in order to interrupt it. By default,
5709 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5711 * Remote protocol timeout
5713 The standard remote protocol includes a new variable `remotetimeout'
5714 that allows you to set the number of seconds before GDB gives up trying
5715 to read from the target. The default value is 2.
5717 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5719 By default GDB will automatically keep track of objects as they are
5720 loaded and unloaded by the dynamic linker. By using the command `set
5721 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5722 when shared library events occur, thus allowing you to set breakpoints
5723 in shared libraries which are explicitly loaded by the inferior.
5725 Note this feature does not work on hpux8. On hpux9 you must link
5726 /usr/lib/end.o into your program. This feature should work
5727 automatically on hpux10.
5729 * Irix 5.x hardware watchpoint support
5731 Irix 5 configurations now support the use of hardware watchpoints.
5733 * Mips protocol "SYN garbage limit"
5735 When debugging a Mips target using the `target mips' protocol, you
5736 may set the number of characters that GDB will ignore by setting
5737 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5738 every character. The default value is 1050.
5740 * Recording and replaying remote debug sessions
5742 If you set `remotelogfile' to the name of a file, gdb will write to it
5743 a recording of a remote debug session. This recording may then be
5744 replayed back to gdb using "gdbreplay". See gdbserver/README for
5745 details. This is useful when you have a problem with GDB while doing
5746 remote debugging; you can make a recording of the session and send it
5747 to someone else, who can then recreate the problem.
5749 * Speedups for remote debugging
5751 GDB includes speedups for downloading and stepping MIPS systems using
5752 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5753 and more efficient S-record downloading.
5755 * Memory use reductions and statistics collection
5757 GDB now uses less memory and reports statistics about memory usage.
5758 Try the `maint print statistics' command, for example.
5760 *** Changes in GDB-4.15:
5762 * Psymtabs for XCOFF
5764 The symbol reader for AIX GDB now uses partial symbol tables. This
5765 can greatly improve startup time, especially for large executables.
5767 * Remote targets use caching
5769 Remote targets now use a data cache to speed up communication with the
5770 remote side. The data cache could lead to incorrect results because
5771 it doesn't know about volatile variables, thus making it impossible to
5772 debug targets which use memory mapped I/O devices. `set remotecache
5773 off' turns the the data cache off.
5775 * Remote targets may have threads
5777 The standard remote protocol now includes support for multiple threads
5778 in the target system, using new protocol commands 'H' and 'T'. See
5779 gdb/remote.c for details.
5783 If GDB is configured with `--enable-netrom', then it will include
5784 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5785 acts as though it is a bank of ROM on the target board, but you can
5786 write into it over the network. GDB's support consists only of
5787 support for fast loading into the emulated ROM; to debug, you must use
5788 another protocol, such as standard remote protocol. The usual
5789 sequence is something like
5791 target nrom <netrom-hostname>
5793 target remote <netrom-hostname>:1235
5797 GDB now includes support for the Apple Macintosh, as a host only. It
5798 may be run as either an MPW tool or as a standalone application, and
5799 it can debug through the serial port. All the usual GDB commands are
5800 available, but to the target command, you must supply "serial" as the
5801 device type instead of "/dev/ttyXX". See mpw-README in the main
5802 directory for more information on how to build. The MPW configuration
5803 scripts */mpw-config.in support only a few targets, and only the
5804 mips-idt-ecoff target has been tested.
5808 GDB configuration now uses autoconf. This is not user-visible,
5809 but does simplify configuration and building.
5813 GDB now supports hpux10.
5815 *** Changes in GDB-4.14:
5817 * New native configurations
5819 x86 FreeBSD i[345]86-*-freebsd
5820 x86 NetBSD i[345]86-*-netbsd
5821 NS32k NetBSD ns32k-*-netbsd
5822 Sparc NetBSD sparc-*-netbsd
5826 A29K VxWorks a29k-*-vxworks
5827 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5828 CPU32 EST-300 emulator m68*-*-est*
5829 PowerPC ELF powerpc-*-elf
5832 * Alpha OSF/1 support for procfs
5834 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5835 possible to attach to running processes. As the mounting of the /proc
5836 filesystem is optional on the Alpha, GDB automatically determines
5837 the availability of /proc during startup. This can lead to problems
5838 if /proc is unmounted after GDB has been started.
5840 * Arguments to user-defined commands
5842 User commands may accept up to 10 arguments separated by whitespace.
5843 Arguments are accessed within the user command via $arg0..$arg9. A
5846 print $arg0 + $arg1 + $arg2
5848 To execute the command use:
5851 Defines the command "adder" which prints the sum of its three arguments.
5852 Note the arguments are text substitutions, so they may reference variables,
5853 use complex expressions, or even perform inferior function calls.
5855 * New `if' and `while' commands
5857 This makes it possible to write more sophisticated user-defined
5858 commands. Both commands take a single argument, which is the
5859 expression to evaluate, and must be followed by the commands to
5860 execute, one per line, if the expression is nonzero, the list being
5861 terminated by the word `end'. The `if' command list may include an
5862 `else' word, which causes the following commands to be executed only
5863 if the expression is zero.
5865 * Fortran source language mode
5867 GDB now includes partial support for Fortran 77. It will recognize
5868 Fortran programs and can evaluate a subset of Fortran expressions, but
5869 variables and functions may not be handled correctly. GDB will work
5870 with G77, but does not yet know much about symbols emitted by other
5873 * Better HPUX support
5875 Most debugging facilities now work on dynamic executables for HPPAs
5876 running hpux9 or later. You can attach to running dynamically linked
5877 processes, but by default the dynamic libraries will be read-only, so
5878 for instance you won't be able to put breakpoints in them. To change
5879 that behavior do the following before running the program:
5885 This will cause the libraries to be mapped private and read-write.
5886 To revert to the normal behavior, do this:
5892 You cannot set breakpoints or examine data in the library until after
5893 the library is loaded if the function/data symbols do not have
5896 GDB can now also read debug symbols produced by the HP C compiler on
5897 HPPAs (sorry, no C++, Fortran or 68k support).
5899 * Target byte order now dynamically selectable
5901 You can choose which byte order to use with a target system, via the
5902 commands "set endian big" and "set endian little", and you can see the
5903 current setting by using "show endian". You can also give the command
5904 "set endian auto", in which case GDB will use the byte order
5905 associated with the executable. Currently, only embedded MIPS
5906 configurations support dynamic selection of target byte order.
5908 * New DOS host serial code
5910 This version uses DPMI interrupts to handle buffered I/O, so you
5911 no longer need to run asynctsr when debugging boards connected to
5914 *** Changes in GDB-4.13:
5916 * New "complete" command
5918 This lists all the possible completions for the rest of the line, if it
5919 were to be given as a command itself. This is intended for use by emacs.
5921 * Trailing space optional in prompt
5923 "set prompt" no longer adds a space for you after the prompt you set. This
5924 allows you to set a prompt which ends in a space or one that does not.
5926 * Breakpoint hit counts
5928 "info break" now displays a count of the number of times the breakpoint
5929 has been hit. This is especially useful in conjunction with "ignore"; you
5930 can ignore a large number of breakpoint hits, look at the breakpoint info
5931 to see how many times the breakpoint was hit, then run again, ignoring one
5932 less than that number, and this will get you quickly to the last hit of
5935 * Ability to stop printing at NULL character
5937 "set print null-stop" will cause GDB to stop printing the characters of
5938 an array when the first NULL is encountered. This is useful when large
5939 arrays actually contain only short strings.
5941 * Shared library breakpoints
5943 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5944 breakpoints in shared libraries before the executable is run.
5946 * Hardware watchpoints
5948 There is a new hardware breakpoint for the watch command for sparclite
5949 targets. See gdb/sparclite/hw_breakpoint.note.
5951 Hardware watchpoints are also now supported under GNU/Linux.
5955 Annotations have been added. These are for use with graphical interfaces,
5956 and are still experimental. Currently only gdba.el uses these.
5958 * Improved Irix 5 support
5960 GDB now works properly with Irix 5.2.
5962 * Improved HPPA support
5964 GDB now works properly with the latest GCC and GAS.
5966 * New native configurations
5968 Sequent PTX4 i[34]86-sequent-ptx4
5969 HPPA running OSF/1 hppa*-*-osf*
5970 Atari TT running SVR4 m68*-*-sysv4*
5971 RS/6000 LynxOS rs6000-*-lynxos*
5975 OS/9000 i[34]86-*-os9k
5976 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5979 * Hitachi SH7000 and E7000-PC ICE support
5981 There is now support for communicating with the Hitachi E7000-PC ICE.
5982 This is available automatically when GDB is configured for the SH.
5986 As usual, a variety of small fixes and improvements, both generic
5987 and configuration-specific. See the ChangeLog for more detail.
5989 *** Changes in GDB-4.12:
5991 * Irix 5 is now supported
5995 GDB-4.12 on the HPPA has a number of changes which make it unable
5996 to debug the output from the currently released versions of GCC and
5997 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
5998 of GCC and GAS, versions of these tools designed to work with GDB-4.12
5999 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6002 *** Changes in GDB-4.11:
6004 * User visible changes:
6008 The "set remotedebug" option is now consistent between the mips remote
6009 target, remote targets using the gdb-specific protocol, UDI (AMD's
6010 debug protocol for the 29k) and the 88k bug monitor. It is now an
6011 integer specifying a debug level (normally 0 or 1, but 2 means more
6012 debugging info for the mips target).
6014 * DEC Alpha native support
6016 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6017 debug info, but GDB works fairly well with the DEC compiler and should
6018 work with a future GCC release. See the README file for a few
6019 Alpha-specific notes.
6021 * Preliminary thread implementation
6023 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6025 * LynxOS native and target support for 386
6027 This release has been hosted on LynxOS 2.2, and also can be configured
6028 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6031 * Improvements in C++ mangling/demangling.
6033 This release has much better g++ debugging, specifically in name
6034 mangling/demangling, virtual function calls, print virtual table,
6035 call methods, ...etc.
6037 *** Changes in GDB-4.10:
6039 * User visible changes:
6041 Remote debugging using the GDB-specific (`target remote') protocol now
6042 supports the `load' command. This is only useful if you have some
6043 other way of getting the stub to the target system, and you can put it
6044 somewhere in memory where it won't get clobbered by the download.
6046 Filename completion now works.
6048 When run under emacs mode, the "info line" command now causes the
6049 arrow to point to the line specified. Also, "info line" prints
6050 addresses in symbolic form (as well as hex).
6052 All vxworks based targets now support a user settable option, called
6053 vxworks-timeout. This option represents the number of seconds gdb
6054 should wait for responses to rpc's. You might want to use this if
6055 your vxworks target is, perhaps, a slow software simulator or happens
6056 to be on the far side of a thin network line.
6060 This release contains support for using a DEC alpha as a GDB host for
6061 cross debugging. Native alpha debugging is not supported yet.
6064 *** Changes in GDB-4.9:
6068 This is the first GDB release which is accompanied by a matching testsuite.
6069 The testsuite requires installation of dejagnu, which should be available
6070 via ftp from most sites that carry GNU software.
6074 'Cfront' style demangling has had its name changed to 'ARM' style, to
6075 emphasize that it was written from the specifications in the C++ Annotated
6076 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6077 disclaimers, it still generated too much confusion with users attempting to
6078 use gdb with AT&T cfront.
6082 GDB now uses a standard remote interface to a simulator library.
6083 So far, the library contains simulators for the Zilog Z8001/2, the
6084 Hitachi H8/300, H8/500 and Super-H.
6086 * New targets supported
6088 H8/300 simulator h8300-hitachi-hms or h8300hms
6089 H8/500 simulator h8500-hitachi-hms or h8500hms
6090 SH simulator sh-hitachi-hms or sh
6091 Z8000 simulator z8k-zilog-none or z8ksim
6092 IDT MIPS board over serial line mips-idt-ecoff
6094 Cross-debugging to GO32 targets is supported. It requires a custom
6095 version of the i386-stub.c module which is integrated with the
6096 GO32 memory extender.
6098 * New remote protocols
6100 MIPS remote debugging protocol.
6102 * New source languages supported
6104 This version includes preliminary support for Chill, a Pascal like language
6105 used by telecommunications companies. Chill support is also being integrated
6106 into the GNU compiler, but we don't know when it will be publically available.
6109 *** Changes in GDB-4.8:
6111 * HP Precision Architecture supported
6113 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6114 version of this support was available as a set of patches from the
6115 University of Utah. GDB does not support debugging of programs
6116 compiled with the HP compiler, because HP will not document their file
6117 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6118 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6120 Many problems in the preliminary version have been fixed.
6122 * Faster and better demangling
6124 We have improved template demangling and fixed numerous bugs in the GNU style
6125 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6126 character types (wchar_t) are now supported. Demangling of each symbol is now
6127 only done once, and is cached when the symbol table for a file is read in.
6128 This results in a small increase in memory usage for C programs, a moderate
6129 increase in memory usage for C++ programs, and a fantastic speedup in
6132 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6133 from the specifications in the Annotated Reference Manual, which AT&T's
6134 compiler does not actually implement.
6136 * G++ multiple inheritance compiler problem
6138 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6139 inheritance lattices was reworked to properly discover ambiguities. We
6140 recently found an example which causes this new algorithm to fail in a
6141 very subtle way, producing bad debug information for those classes.
6142 The file 'gcc.patch' (in this directory) can be applied to gcc to
6143 circumvent the problem. A future GCC release will contain a complete
6146 The previous G++ debug info problem (mentioned below for the gdb-4.7
6147 release) is fixed in gcc version 2.3.2.
6149 * Improved configure script
6151 The `configure' script will now attempt to guess your system type if
6152 you don't supply a host system type. The old scheme of supplying a
6153 host system triplet is preferable over using this. All the magic is
6154 done in the new `config.guess' script. Examine it for details.
6156 We have also brought our configure script much more in line with the FSF's
6157 version. It now supports the --with-xxx options. In particular,
6158 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6159 The resulting GDB will not be able to read arbitrary object file formats --
6160 only the format ``expected'' to be used on the configured target system.
6161 We hope to make this the default in a future release.
6163 * Documentation improvements
6165 There's new internal documentation on how to modify GDB, and how to
6166 produce clean changes to the code. We implore people to read it
6167 before submitting changes.
6169 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6170 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6171 `info' files are also provided. To build `info' files from scratch,
6172 you will need the latest `makeinfo' release, which will be available in
6173 a future texinfo-X.Y release.
6175 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6176 We're not sure exactly which versions have this problem, but it has
6177 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6178 or better. If that isn't possible, there is a patch in
6179 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6180 around this problem.
6184 GDB now supports array constants that can be used in expressions typed in by
6185 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6186 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6189 The new directory `gdb/sparclite' contains a program that demonstrates
6190 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6192 * New native hosts supported
6194 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6195 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6197 * New targets supported
6199 AMD 29k family via UDI a29k-amd-udi or udi29k
6201 * New file formats supported
6203 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6204 HPUX core files, and SCO 3.2v2 core files.
6208 Attaching to processes now works again; thanks for the many bug reports.
6210 We have also stomped on a bunch of core dumps caused by
6211 printf_filtered("%s") problems.
6213 We eliminated a copyright problem on the rpc and ptrace header files
6214 for VxWorks, which was discovered at the last minute during the 4.7
6215 release. You should now be able to build a VxWorks GDB.
6217 You can now interrupt gdb while an attached process is running. This
6218 will cause the attached process to stop, and give control back to GDB.
6220 We fixed problems caused by using too many file descriptors
6221 for reading symbols from object files and libraries. This was
6222 especially a problem for programs that used many (~100) shared
6225 The `step' command now only enters a subroutine if there is line number
6226 information for the subroutine. Otherwise it acts like the `next'
6227 command. Previously, `step' would enter subroutines if there was
6228 any debugging information about the routine. This avoids problems
6229 when using `cc -g1' on MIPS machines.
6231 * Internal improvements
6233 GDB's internal interfaces have been improved to make it easier to support
6234 debugging of multiple languages in the future.
6236 GDB now uses a common structure for symbol information internally.
6237 Minimal symbols (derived from linkage symbols in object files), partial
6238 symbols (from a quick scan of debug information), and full symbols
6239 contain a common subset of information, making it easier to write
6240 shared code that handles any of them.
6242 * New command line options
6244 We now accept --silent as an alias for --quiet.
6248 The memory-mapped-malloc library is now licensed under the GNU Library
6249 General Public License.
6251 *** Changes in GDB-4.7:
6253 * Host/native/target split
6255 GDB has had some major internal surgery to untangle the support for
6256 hosts and remote targets. Now, when you configure GDB for a remote
6257 target, it will no longer load in all of the support for debugging
6258 local programs on the host. When fully completed and tested, this will
6259 ensure that arbitrary host/target combinations are possible.
6261 The primary conceptual shift is to separate the non-portable code in
6262 GDB into three categories. Host specific code is required any time GDB
6263 is compiled on that host, regardless of the target. Target specific
6264 code relates to the peculiarities of the target, but can be compiled on
6265 any host. Native specific code is everything else: it can only be
6266 built when the host and target are the same system. Child process
6267 handling and core file support are two common `native' examples.
6269 GDB's use of /proc for controlling Unix child processes is now cleaner.
6270 It has been split out into a single module under the `target_ops' vector,
6271 plus two native-dependent functions for each system that uses /proc.
6273 * New hosts supported
6275 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6276 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6277 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6279 * New targets supported
6281 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6282 68030 and CPU32 m68030-*-*, m68332-*-*
6284 * New native hosts supported
6286 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6287 (386bsd is not well tested yet)
6288 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6290 * New file formats supported
6292 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6293 supports reading of `a.out.adobe' object files, which are an a.out
6294 format extended with minimal information about multiple sections.
6298 `show copying' is the same as the old `info copying'.
6299 `show warranty' is the same as `info warrantee'.
6300 These were renamed for consistency. The old commands continue to work.
6302 `info handle' is a new alias for `info signals'.
6304 You can now define pre-command hooks, which attach arbitrary command
6305 scripts to any command. The commands in the hook will be executed
6306 prior to the user's command. You can also create a hook which will be
6307 executed whenever the program stops. See gdb.texinfo.
6311 We now deal with Cfront style name mangling, and can even extract type
6312 info from mangled symbols. GDB can automatically figure out which
6313 symbol mangling style your C++ compiler uses.
6315 Calling of methods and virtual functions has been improved as well.
6319 The crash that occured when debugging Sun Ansi-C compiled binaries is
6320 fixed. This was due to mishandling of the extra N_SO stabs output
6323 We also finally got Ultrix 4.2 running in house, and fixed core file
6324 support, with help from a dozen people on the net.
6326 John M. Farrell discovered that the reason that single-stepping was so
6327 slow on all of the Mips based platforms (primarily SGI and DEC) was
6328 that we were trying to demangle and lookup a symbol used for internal
6329 purposes on every instruction that was being stepped through. Changing
6330 the name of that symbol so that it couldn't be mistaken for a C++
6331 mangled symbol sped things up a great deal.
6333 Rich Pixley sped up symbol lookups in general by getting much smarter
6334 about when C++ symbol mangling is necessary. This should make symbol
6335 completion (TAB on the command line) much faster. It's not as fast as
6336 we'd like, but it's significantly faster than gdb-4.6.
6340 A new user controllable variable 'call_scratch_address' can
6341 specify the location of a scratch area to be used when GDB
6342 calls a function in the target. This is necessary because the
6343 usual method of putting the scratch area on the stack does not work
6344 in systems that have separate instruction and data spaces.
6346 We integrated changes to support the 29k UDI (Universal Debugger
6347 Interface), but discovered at the last minute that we didn't have all
6348 of the appropriate copyright paperwork. We are working with AMD to
6349 resolve this, and hope to have it available soon.
6353 We have sped up the remote serial line protocol, especially for targets
6354 with lots of registers. It now supports a new `expedited status' ('T')
6355 message which can be used in place of the existing 'S' status message.
6356 This allows the remote stub to send only the registers that GDB
6357 needs to make a quick decision about single-stepping or conditional
6358 breakpoints, eliminating the need to fetch the entire register set for
6359 each instruction being stepped through.
6361 The GDB remote serial protocol now implements a write-through cache for
6362 registers, only re-reading the registers if the target has run.
6364 There is also a new remote serial stub for SPARC processors. You can
6365 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6366 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6367 processor with a serial port.
6371 Configure.in files have become much easier to read and modify. A new
6372 `table driven' format makes it more obvious what configurations are
6373 supported, and what files each one uses.
6377 There is a new opcodes library which will eventually contain all of the
6378 disassembly routines and opcode tables. At present, it only contains
6379 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6380 disassembler (binutils/objdump) to share these routines.
6382 The libiberty library is now copylefted under the GNU Library General
6383 Public License. This allows more liberal use, and was done so libg++
6384 can use it. This makes no difference to GDB, since the Library License
6385 grants all the rights from the General Public License.
6389 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6390 reference to the stabs symbol info used by the debugger. It is (as far
6391 as we know) the only published document on this fascinating topic. We
6392 encourage you to read it, compare it to the stabs information on your
6393 system, and send improvements on the document in general (to
6394 bug-gdb@prep.ai.mit.edu).
6396 And, of course, many bugs have been fixed.
6399 *** Changes in GDB-4.6:
6401 * Better support for C++ function names
6403 GDB now accepts as input the "demangled form" of C++ overloaded function
6404 names and member function names, and can do command completion on such names
6405 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6406 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6407 Make use of command completion, it is your friend.
6409 GDB also now accepts a variety of C++ mangled symbol formats. They are
6410 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6411 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6412 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6413 for the list of formats.
6415 * G++ symbol mangling problem
6417 Recent versions of gcc have a bug in how they emit debugging information for
6418 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6419 directory) can be applied to gcc to fix the problem. Alternatively, if you
6420 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6421 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6422 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6425 * New 'maintenance' command
6427 All of the commands related to hacking GDB internals have been moved out of
6428 the main command set, and now live behind the 'maintenance' command. This
6429 can also be abbreviated as 'mt'. The following changes were made:
6431 dump-me -> maintenance dump-me
6432 info all-breakpoints -> maintenance info breakpoints
6433 printmsyms -> maintenance print msyms
6434 printobjfiles -> maintenance print objfiles
6435 printpsyms -> maintenance print psymbols
6436 printsyms -> maintenance print symbols
6438 The following commands are new:
6440 maintenance demangle Call internal GDB demangler routine to
6441 demangle a C++ link name and prints the result.
6442 maintenance print type Print a type chain for a given symbol
6444 * Change to .gdbinit file processing
6446 We now read the $HOME/.gdbinit file before processing the argv arguments
6447 (e.g. reading symbol files or core files). This allows global parameters to
6448 be set, which will apply during the symbol reading. The ./.gdbinit is still
6449 read after argv processing.
6451 * New hosts supported
6453 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6455 GNU/Linux support i386-unknown-linux or linux
6457 We are also including code to support the HP/PA running BSD and HPUX. This
6458 is almost guaranteed not to work, as we didn't have time to test or build it
6459 for this release. We are including it so that the more adventurous (or
6460 masochistic) of you can play with it. We also had major problems with the
6461 fact that the compiler that we got from HP doesn't support the -g option.
6464 * New targets supported
6466 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6468 * More smarts about finding #include files
6470 GDB now remembers the compilation directory for all include files, and for
6471 all files from which C is generated (like yacc and lex sources). This
6472 greatly improves GDB's ability to find yacc/lex sources, and include files,
6473 especially if you are debugging your program from a directory different from
6474 the one that contains your sources.
6476 We also fixed a bug which caused difficulty with listing and setting
6477 breakpoints in include files which contain C code. (In the past, you had to
6478 try twice in order to list an include file that you hadn't looked at before.)
6480 * Interesting infernals change
6482 GDB now deals with arbitrary numbers of sections, where the symbols for each
6483 section must be relocated relative to that section's landing place in the
6484 target's address space. This work was needed to support ELF with embedded
6485 stabs used by Solaris-2.0.
6487 * Bug fixes (of course!)
6489 There have been loads of fixes for the following things:
6490 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6491 i960, stabs, DOS(GO32), procfs, etc...
6493 See the ChangeLog for details.
6495 *** Changes in GDB-4.5:
6497 * New machines supported (host and target)
6499 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6501 SGI Irix-4.x mips-sgi-irix4 or iris4
6503 * New malloc package
6505 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6506 Mmalloc is capable of handling mutiple heaps of memory. It is also
6507 capable of saving a heap to a file, and then mapping it back in later.
6508 This can be used to greatly speedup the startup of GDB by using a
6509 pre-parsed symbol table which lives in a mmalloc managed heap. For
6510 more details, please read mmalloc/mmalloc.texi.
6514 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6515 'help info proc' for details.
6517 * MIPS ecoff symbol table format
6519 The code that reads MIPS symbol table format is now supported on all hosts.
6520 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6523 * File name changes for MS-DOS
6525 Many files in the config directories have been renamed to make it easier to
6526 support GDB on MS-DOSe systems (which have very restrictive file name
6527 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6528 environment) is close to working but has some remaining problems. Note
6529 that debugging of DOS programs is not supported, due to limitations
6530 in the ``operating system'', but it can be used to host cross-debugging.
6532 * Cross byte order fixes
6534 Many fixes have been made to support cross debugging of Sparc and MIPS
6535 targets from hosts whose byte order differs.
6537 * New -mapped and -readnow options
6539 If memory-mapped files are available on your system through the 'mmap'
6540 system call, you can use the -mapped option on the `file' or
6541 `symbol-file' commands to cause GDB to write the symbols from your
6542 program into a reusable file. If the program you are debugging is
6543 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6544 Future GDB debugging sessions will notice the presence of this file,
6545 and will quickly map in symbol information from it, rather than reading
6546 the symbol table from the executable program. Using the '-mapped'
6547 option in a GDB `file' or `symbol-file' command has the same effect as
6548 starting GDB with the '-mapped' command-line option.
6550 You can cause GDB to read the entire symbol table immediately by using
6551 the '-readnow' option with any of the commands that load symbol table
6552 information (or on the GDB command line). This makes the command
6553 slower, but makes future operations faster.
6555 The -mapped and -readnow options are typically combined in order to
6556 build a `fred.syms' file that contains complete symbol information.
6557 A simple GDB invocation to do nothing but build a `.syms' file for future
6560 gdb -batch -nx -mapped -readnow programname
6562 The `.syms' file is specific to the host machine on which GDB is run.
6563 It holds an exact image of GDB's internal symbol table. It cannot be
6564 shared across multiple host platforms.
6566 * longjmp() handling
6568 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6569 siglongjmp() without losing control. This feature has not yet been ported to
6570 all systems. It currently works on many 386 platforms, all MIPS-based
6571 platforms (SGI, DECstation, etc), and Sun3/4.
6575 Preliminary work has been put in to support the new Solaris OS from Sun. At
6576 this time, it can control and debug processes, but it is not capable of
6581 As always, many many bug fixes. The major areas were with g++, and mipsread.
6582 People using the MIPS-based platforms should experience fewer mysterious
6583 crashes and trashed symbol tables.
6585 *** Changes in GDB-4.4:
6587 * New machines supported (host and target)
6589 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6591 BSD Reno on Vax vax-dec-bsd
6592 Ultrix on Vax vax-dec-ultrix
6594 * New machines supported (target)
6596 AMD 29000 embedded, using EBMON a29k-none-none
6600 GDB continues to improve its handling of C++. `References' work better.
6601 The demangler has also been improved, and now deals with symbols mangled as
6602 per the Annotated C++ Reference Guide.
6604 GDB also now handles `stabs' symbol information embedded in MIPS
6605 `ecoff' symbol tables. Since the ecoff format was not easily
6606 extensible to handle new languages such as C++, this appeared to be a
6607 good way to put C++ debugging info into MIPS binaries. This option
6608 will be supported in the GNU C compiler, version 2, when it is
6611 * New features for SVR4
6613 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6614 shared libraries. Debugging dynamically linked programs should present
6615 only minor differences from debugging statically linked programs.
6617 The `info proc' command will print out information about any process
6618 on an SVR4 system (including the one you are debugging). At the moment,
6619 it prints the address mappings of the process.
6621 If you bring up GDB on another SVR4 system, please send mail to
6622 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6624 * Better dynamic linking support in SunOS
6626 Reading symbols from shared libraries which contain debugging symbols
6627 now works properly. However, there remain issues such as automatic
6628 skipping of `transfer vector' code during function calls, which
6629 make it harder to debug code in a shared library, than to debug the
6630 same code linked statically.
6634 GDB is now using the latest `getopt' routines from the FSF. This
6635 version accepts the -- prefix for options with long names. GDB will
6636 continue to accept the old forms (-option and +option) as well.
6637 Various single letter abbreviations for options have been explicity
6638 added to the option table so that they won't get overshadowed in the
6639 future by other options that begin with the same letter.
6643 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6644 Many assorted bugs have been handled. Many more remain to be handled.
6645 See the various ChangeLog files (primarily in gdb and bfd) for details.
6648 *** Changes in GDB-4.3:
6650 * New machines supported (host and target)
6652 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6653 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6654 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6656 * Almost SCO Unix support
6658 We had hoped to support:
6659 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6660 (except for core file support), but we discovered very late in the release
6661 that it has problems with process groups that render gdb unusable. Sorry
6662 about that. I encourage people to fix it and post the fixes.
6664 * Preliminary ELF and DWARF support
6666 GDB can read ELF object files on System V Release 4, and can handle
6667 debugging records for C, in DWARF format, in ELF files. This support
6668 is preliminary. If you bring up GDB on another SVR4 system, please
6669 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6674 GDB now uses the latest `readline' library. One user-visible change
6675 is that two tabs will list possible command completions, which previously
6676 required typing M-? (meta-question mark, or ESC ?).
6680 The `stepi' bug that many of you noticed has been squashed.
6681 Many bugs in C++ have been handled. Many more remain to be handled.
6682 See the various ChangeLog files (primarily in gdb and bfd) for details.
6684 * State of the MIPS world (in case you wondered):
6686 GDB can understand the symbol tables emitted by the compilers
6687 supplied by most vendors of MIPS-based machines, including DEC. These
6688 symbol tables are in a format that essentially nobody else uses.
6690 Some versions of gcc come with an assembler post-processor called
6691 mips-tfile. This program is required if you want to do source-level
6692 debugging of gcc-compiled programs. I believe FSF does not ship
6693 mips-tfile with gcc version 1, but it will eventually come with gcc
6696 Debugging of g++ output remains a problem. g++ version 1.xx does not
6697 really support it at all. (If you're lucky, you should be able to get
6698 line numbers and stack traces to work, but no parameters or local
6699 variables.) With some work it should be possible to improve the
6702 When gcc version 2 is released, you will have somewhat better luck.
6703 However, even then you will get confusing results for inheritance and
6706 We will eventually provide full debugging of g++ output on
6707 DECstations. This will probably involve some kind of stabs-in-ecoff
6708 encapulation, but the details have not been worked out yet.
6711 *** Changes in GDB-4.2:
6713 * Improved configuration
6715 Only one copy of `configure' exists now, and it is not self-modifying.
6716 Porting BFD is simpler.
6720 The `step' and `next' commands now only stop at the first instruction
6721 of a source line. This prevents the multiple stops that used to occur
6722 in switch statements, for-loops, etc. `Step' continues to stop if a
6723 function that has debugging information is called within the line.
6727 Lots of small bugs fixed. More remain.
6729 * New host supported (not target)
6731 Intel 386 PC clone running Mach i386-none-mach
6734 *** Changes in GDB-4.1:
6736 * Multiple source language support
6738 GDB now has internal scaffolding to handle several source languages.
6739 It determines the type of each source file from its filename extension,
6740 and will switch expression parsing and number formatting to match the
6741 language of the function in the currently selected stack frame.
6742 You can also specifically set the language to be used, with
6743 `set language c' or `set language modula-2'.
6747 GDB now has preliminary support for the GNU Modula-2 compiler,
6748 currently under development at the State University of New York at
6749 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6750 continue through the fall of 1991 and into 1992.
6752 Other Modula-2 compilers are currently not supported, and attempting to
6753 debug programs compiled with them will likely result in an error as the
6754 symbol table is read. Feel free to work on it, though!
6756 There are hooks in GDB for strict type checking and range checking,
6757 in the `Modula-2 philosophy', but they do not currently work.
6761 GDB can now write to executable and core files (e.g. patch
6762 a variable's value). You must turn this switch on, specify
6763 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6764 by assigning a new value to a variable. Modifications take
6767 * Automatic SunOS shared library reading
6769 When you run your program, GDB automatically determines where its
6770 shared libraries (if any) have been loaded, and reads their symbols.
6771 The `share' command is no longer needed. This also works when
6772 examining core files.
6776 You can specify the number of lines that the `list' command shows.
6779 * New machines supported (host and target)
6781 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6782 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6783 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6785 * New hosts supported (not targets)
6787 IBM RT/PC: romp-ibm-aix or rtpc
6789 * New targets supported (not hosts)
6791 AMD 29000 embedded with COFF a29k-none-coff
6792 AMD 29000 embedded with a.out a29k-none-aout
6793 Ultracomputer remote kernel debug a29k-nyu-kern
6795 * New remote interfaces
6801 *** Changes in GDB-4.0:
6805 Wide output is wrapped at good places to make the output more readable.
6807 Gdb now supports cross-debugging from a host machine of one type to a
6808 target machine of another type. Communication with the target system
6809 is over serial lines. The ``target'' command handles connecting to the
6810 remote system; the ``load'' command will download a program into the
6811 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6812 also supports debugging of realtime processes running under VxWorks,
6813 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6814 stub on the target system.
6816 New CPUs supported include the AMD 29000 and Intel 960.
6818 GDB now reads object files and symbol tables via a ``binary file''
6819 library, which allows a single copy of GDB to debug programs of multiple
6820 object file types such as a.out and coff.
6822 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6823 refcard.dvi and refcard.ps are available to format it).
6826 * Control-Variable user interface simplified
6828 All variables that control the operation of the debugger can be set
6829 by the ``set'' command, and displayed by the ``show'' command.
6831 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6832 ``Show prompt'' produces the response:
6833 Gdb's prompt is new-gdb=>.
6835 What follows are the NEW set commands. The command ``help set'' will
6836 print a complete list of old and new set commands. ``help set FOO''
6837 will give a longer description of the variable FOO. ``show'' will show
6838 all of the variable descriptions and their current settings.
6840 confirm on/off: Enables warning questions for operations that are
6841 hard to recover from, e.g. rerunning the program while
6842 it is already running. Default is ON.
6844 editing on/off: Enables EMACS style command line editing
6845 of input. Previous lines can be recalled with
6846 control-P, the current line can be edited with control-B,
6847 you can search for commands with control-R, etc.
6850 history filename NAME: NAME is where the gdb command history
6851 will be stored. The default is .gdb_history,
6852 or the value of the environment variable
6855 history size N: The size, in commands, of the command history. The
6856 default is 256, or the value of the environment variable
6859 history save on/off: If this value is set to ON, the history file will
6860 be saved after exiting gdb. If set to OFF, the
6861 file will not be saved. The default is OFF.
6863 history expansion on/off: If this value is set to ON, then csh-like
6864 history expansion will be performed on
6865 command line input. The default is OFF.
6867 radix N: Sets the default radix for input and output. It can be set
6868 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6869 in the current radix, so "set radix 10" is always a no-op.
6871 height N: This integer value is the number of lines on a page. Default
6872 is 24, the current `stty rows'' setting, or the ``li#''
6873 setting from the termcap entry matching the environment
6876 width N: This integer value is the number of characters on a line.
6877 Default is 80, the current `stty cols'' setting, or the ``co#''
6878 setting from the termcap entry matching the environment
6881 Note: ``set screensize'' is obsolete. Use ``set height'' and
6882 ``set width'' instead.
6884 print address on/off: Print memory addresses in various command displays,
6885 such as stack traces and structure values. Gdb looks
6886 more ``symbolic'' if you turn this off; it looks more
6887 ``machine level'' with it on. Default is ON.
6889 print array on/off: Prettyprint arrays. New convenient format! Default
6892 print demangle on/off: Print C++ symbols in "source" form if on,
6895 print asm-demangle on/off: Same, for assembler level printouts
6898 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6901 * Support for Epoch Environment.
6903 The epoch environment is a version of Emacs v18 with windowing. One
6904 new command, ``inspect'', is identical to ``print'', except that if you
6905 are running in the epoch environment, the value is printed in its own
6909 * Support for Shared Libraries
6911 GDB can now debug programs and core files that use SunOS shared libraries.
6912 Symbols from a shared library cannot be referenced
6913 before the shared library has been linked with the program (this
6914 happens after you type ``run'' and before the function main() is entered).
6915 At any time after this linking (including when examining core files
6916 from dynamically linked programs), gdb reads the symbols from each
6917 shared library when you type the ``sharedlibrary'' command.
6918 It can be abbreviated ``share''.
6920 sharedlibrary REGEXP: Load shared object library symbols for files
6921 matching a unix regular expression. No argument
6922 indicates to load symbols for all shared libraries.
6924 info sharedlibrary: Status of loaded shared libraries.
6929 A watchpoint stops execution of a program whenever the value of an
6930 expression changes. Checking for this slows down execution
6931 tremendously whenever you are in the scope of the expression, but is
6932 quite useful for catching tough ``bit-spreader'' or pointer misuse
6933 problems. Some machines such as the 386 have hardware for doing this
6934 more quickly, and future versions of gdb will use this hardware.
6936 watch EXP: Set a watchpoint (breakpoint) for an expression.
6938 info watchpoints: Information about your watchpoints.
6940 delete N: Deletes watchpoint number N (same as breakpoints).
6941 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6942 enable N: Re-enables watchpoint number N (same as breakpoints).
6945 * C++ multiple inheritance
6947 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6950 * C++ exception handling
6952 Gdb now supports limited C++ exception handling. Besides the existing
6953 ability to breakpoint on an exception handler, gdb can breakpoint on
6954 the raising of an exception (before the stack is peeled back to the
6957 catch FOO: If there is a FOO exception handler in the dynamic scope,
6958 set a breakpoint to catch exceptions which may be raised there.
6959 Multiple exceptions (``catch foo bar baz'') may be caught.
6961 info catch: Lists all exceptions which may be caught in the
6962 current stack frame.
6965 * Minor command changes
6967 The command ``call func (arg, arg, ...)'' now acts like the print
6968 command, except it does not print or save a value if the function's result
6969 is void. This is similar to dbx usage.
6971 The ``up'' and ``down'' commands now always print the frame they end up
6972 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6973 frames without printing.
6975 * New directory command
6977 'dir' now adds directories to the FRONT of the source search path.
6978 The path starts off empty. Source files that contain debug information
6979 about the directory in which they were compiled can be found even
6980 with an empty path; Sun CC and GCC include this information. If GDB can't
6981 find your source file in the current directory, type "dir .".
6983 * Configuring GDB for compilation
6985 For normal use, type ``./configure host''. See README or gdb.texinfo
6988 GDB now handles cross debugging. If you are remotely debugging between
6989 two different machines, type ``./configure host -target=targ''.
6990 Host is the machine where GDB will run; targ is the machine
6991 where the program that you are debugging will run.