1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.1
6 * The commands 'info variables/functions/types' now show the source line
7 numbers of symbol definitions when available.
9 * 'info proc' now works on running processes on FreeBSD systems and core
10 files created on FreeBSD systems.
12 * C expressions can now use _Alignof, and C++ expressions can now use
19 Control display of debugging info regarding the FreeBSD native target.
21 set|show varsize-limit
22 This new setting allows the user to control the maximum size of Ada
23 objects being printed when those objects have a variable type,
24 instead of that maximum size being hardcoded to 65536 bytes.
26 set|show record btrace cpu
27 Controls the processor to be used for enabling errata workarounds for
32 RiscV ELF riscv*-*-elf
34 * Removed targets and native configurations
36 m88k running OpenBSD m88*-*-openbsd*
37 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
38 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
39 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
41 *** Changes in GDB 8.1
43 * GDB now supports dynamically creating arbitrary register groups specified
44 in XML target descriptions. This allows for finer grain grouping of
45 registers on systems with a large amount of registers.
47 * The 'ptype' command now accepts a '/o' flag, which prints the
48 offsets and sizes of fields in a struct, like the pahole(1) tool.
50 * New "--readnever" command line option instructs GDB to not read each
51 symbol file's symbolic debug information. This makes startup faster
52 but at the expense of not being able to perform symbolic debugging.
53 This option is intended for use cases where symbolic debugging will
54 not be used, e.g., when you only need to dump the debuggee's core.
56 * GDB now uses the GNU MPFR library, if available, to emulate target
57 floating-point arithmetic during expression evaluation when the target
58 uses different floating-point formats than the host. At least version
59 3.1 of GNU MPFR is required.
61 * GDB now supports access to the guarded-storage-control registers and the
62 software-based guarded-storage broadcast control registers on IBM z14.
64 * On Unix systems, GDB now supports transmitting environment variables
65 that are to be set or unset to GDBserver. These variables will
66 affect the environment to be passed to the remote inferior.
68 To inform GDB of environment variables that are to be transmitted to
69 GDBserver, use the "set environment" command. Only user set
70 environment variables are sent to GDBserver.
72 To inform GDB of environment variables that are to be unset before
73 the remote inferior is started by the GDBserver, use the "unset
76 * Completion improvements
78 ** GDB can now complete function parameters in linespecs and
79 explicit locations without quoting. When setting breakpoints,
80 quoting around functions names to help with TAB-completion is
81 generally no longer necessary. For example, this now completes
84 (gdb) b function(in[TAB]
87 Related, GDB is no longer confused with completing functions in
88 C++ anonymous namespaces:
91 (gdb) b (anonymous namespace)::[TAB][TAB]
92 (anonymous namespace)::a_function()
93 (anonymous namespace)::b_function()
95 ** GDB now has much improved linespec and explicit locations TAB
96 completion support, that better understands what you're
97 completing and offers better suggestions. For example, GDB no
98 longer offers data symbols as possible completions when you're
101 ** GDB now TAB-completes label symbol names.
103 ** The "complete" command now mimics TAB completion accurately.
105 * New command line options (gcore)
108 Dump all memory mappings.
110 * Breakpoints on C++ functions are now set on all scopes by default
112 By default, breakpoints on functions/methods are now interpreted as
113 specifying all functions with the given name ignoring missing
114 leading scopes (namespaces and classes).
116 For example, assuming a C++ program with symbols named:
121 both commands "break func()" and "break B::func()" set a breakpoint
124 You can use the new flag "-qualified" to override this. This makes
125 GDB interpret the specified function name as a complete
126 fully-qualified name instead. For example, using the same C++
127 program, the "break -q B::func" command sets a breakpoint on
128 "B::func", only. A parameter has been added to the Python
129 gdb.Breakpoint constructor to achieve the same result when creating
130 a breakpoint from Python.
132 * Breakpoints on functions marked with C++ ABI tags
134 GDB can now set breakpoints on functions marked with C++ ABI tags
135 (e.g., [abi:cxx11]). See here for a description of ABI tags:
136 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
138 Functions with a C++11 abi tag are demangled/displayed like this:
140 function[abi:cxx11](int)
143 You can now set a breakpoint on such functions simply as if they had
146 (gdb) b function(int)
148 Or if you need to disambiguate between tags, like:
150 (gdb) b function[abi:other_tag](int)
152 Tab completion was adjusted accordingly as well.
156 ** New events gdb.new_inferior, gdb.inferior_deleted, and
157 gdb.new_thread are emitted. See the manual for further
158 description of these.
160 ** A new function, "gdb.rbreak" has been added to the Python API.
161 This function allows the setting of a large number of breakpoints
162 via a regex pattern in Python. See the manual for further details.
164 ** Python breakpoints can now accept explicit locations. See the
165 manual for a further description of this feature.
168 * New features in the GDB remote stub, GDBserver
170 ** GDBserver is now able to start inferior processes with a
171 specified initial working directory.
173 The user can set the desired working directory to be used from
174 GDB using the new "set cwd" command.
176 ** New "--selftest" command line option runs some GDBserver self
177 tests. These self tests are disabled in releases.
179 ** On Unix systems, GDBserver now does globbing expansion and variable
180 substitution in inferior command line arguments.
182 This is done by starting inferiors using a shell, like GDB does.
183 See "set startup-with-shell" in the user manual for how to disable
184 this from GDB when using "target extended-remote". When using
185 "target remote", you can disable the startup with shell by using the
186 new "--no-startup-with-shell" GDBserver command line option.
188 ** On Unix systems, GDBserver now supports receiving environment
189 variables that are to be set or unset from GDB. These variables
190 will affect the environment to be passed to the inferior.
192 * When catching an Ada exception raised with a message, GDB now prints
193 the message in the catchpoint hit notification. In GDB/MI mode, that
194 information is provided as an extra field named "exception-message"
195 in the *stopped notification.
197 * Trait objects can now be inspected When debugging Rust code. This
198 requires compiler support which will appear in Rust 1.24.
202 QEnvironmentHexEncoded
203 Inform GDBserver of an environment variable that is to be passed to
204 the inferior when starting it.
207 Inform GDBserver of an environment variable that is to be unset
208 before starting the remote inferior.
211 Inform GDBserver that the environment should be reset (i.e.,
212 user-set environment variables should be unset).
215 Indicates whether the inferior must be started with a shell or not.
218 Tell GDBserver that the inferior to be started should use a specific
221 * The "maintenance print c-tdesc" command now takes an optional
222 argument which is the file name of XML target description.
224 * The "maintenance selftest" command now takes an optional argument to
225 filter the tests to be run.
227 * The "enable", and "disable" commands now accept a range of
228 breakpoint locations, e.g. "enable 1.3-5".
233 Set and show the current working directory for the inferior.
236 Set and show compilation command used for compiling and injecting code
237 with the 'compile' commands.
239 set debug separate-debug-file
240 show debug separate-debug-file
241 Control the display of debug output about separate debug file search.
243 set dump-excluded-mappings
244 show dump-excluded-mappings
245 Control whether mappings marked with the VM_DONTDUMP flag should be
246 dumped when generating a core file.
249 List the registered selftests.
252 Start the debugged program stopping at the first instruction.
255 Control display of debugging messages related to OpenRISC targets.
257 set|show print type nested-type-limit
258 Set and show the limit of nesting level for nested types that the
259 type printer will show.
261 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
264 * Safer/improved support for debugging with no debug info
266 GDB no longer assumes functions with no debug information return
269 This means that GDB now refuses to call such functions unless you
270 tell it the function's type, by either casting the call to the
271 declared return type, or by casting the function to a function
272 pointer of the right type, and calling that:
274 (gdb) p getenv ("PATH")
275 'getenv' has unknown return type; cast the call to its declared return type
276 (gdb) p (char *) getenv ("PATH")
277 $1 = 0x7fffffffe "/usr/local/bin:/"...
278 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
279 $2 = 0x7fffffffe "/usr/local/bin:/"...
281 Similarly, GDB no longer assumes that global variables with no debug
282 info have type 'int', and refuses to print the variable's value
283 unless you tell it the variable's type:
286 'var' has unknown type; cast it to its declared type
290 * New native configurations
292 FreeBSD/aarch64 aarch64*-*-freebsd*
293 FreeBSD/arm arm*-*-freebsd*
297 FreeBSD/aarch64 aarch64*-*-freebsd*
298 FreeBSD/arm arm*-*-freebsd*
299 OpenRISC ELF or1k*-*-elf
301 * Removed targets and native configurations
303 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
305 *** Changes in GDB 8.0
307 * GDB now supports access to the PKU register on GNU/Linux. The register is
308 added by the Memory Protection Keys for Userspace feature which will be
309 available in future Intel CPUs.
311 * GDB now supports C++11 rvalue references.
315 ** New functions to start, stop and access a running btrace recording.
316 ** Rvalue references are now supported in gdb.Type.
318 * GDB now supports recording and replaying rdrand and rdseed Intel 64
321 * Building GDB and GDBserver now requires a C++11 compiler.
323 For example, GCC 4.8 or later.
325 It is no longer possible to build GDB or GDBserver with a C
326 compiler. The --disable-build-with-cxx configure option has been
329 * Building GDB and GDBserver now requires GNU make >= 3.81.
331 It is no longer supported to build GDB or GDBserver with another
332 implementation of the make program or an earlier version of GNU make.
334 * Native debugging on MS-Windows supports command-line redirection
336 Command-line arguments used for starting programs on MS-Windows can
337 now include redirection symbols supported by native Windows shells,
338 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
339 as "run", "start", and "set args", as well as the corresponding MI
342 * Support for thread names on MS-Windows.
344 GDB now catches and handles the special exception that programs
345 running on MS-Windows use to assign names to threads in the
348 * Support for Java programs compiled with gcj has been removed.
350 * User commands now accept an unlimited number of arguments.
351 Previously, only up to 10 was accepted.
353 * The "eval" command now expands user-defined command arguments.
355 This makes it easier to process a variable number of arguments:
360 eval "print $arg%d", $i
365 * Target descriptions can now describe registers for sparc32 and sparc64.
367 * GDB now supports DWARF version 5 (debug information format).
368 Its .debug_names index is not yet supported.
370 * New native configurations
372 FreeBSD/mips mips*-*-freebsd
376 Synopsys ARC arc*-*-elf32
377 FreeBSD/mips mips*-*-freebsd
379 * Removed targets and native configurations
381 Alpha running FreeBSD alpha*-*-freebsd*
382 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
387 Erases all the flash memory regions reported by the target.
389 maint print arc arc-instruction address
390 Print internal disassembler information about instruction at a given address.
394 set disassembler-options
395 show disassembler-options
396 Controls the passing of target specific information to the disassembler.
397 If it is necessary to specify more than one disassembler option then
398 multiple options can be placed together into a comma separated list.
399 The default value is the empty string. Currently, the only supported
400 targets are ARM, PowerPC and S/390.
405 Erases all the flash memory regions reported by the target. This is
406 equivalent to the CLI command flash-erase.
408 -file-list-shared-libraries
409 List the shared libraries in the program. This is
410 equivalent to the CLI command "info shared".
413 Catchpoints stopping the program when Ada exceptions are
414 handled. This is equivalent to the CLI command "catch handlers".
416 *** Changes in GDB 7.12
418 * GDB and GDBserver now build with a C++ compiler by default.
420 The --enable-build-with-cxx configure option is now enabled by
421 default. One must now explicitly configure with
422 --disable-build-with-cxx in order to build with a C compiler. This
423 option will be removed in a future release.
425 * GDBserver now supports recording btrace without maintaining an active
428 * GDB now supports a negative repeat count in the 'x' command to examine
429 memory backward from the given address. For example:
432 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
433 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
434 (gdb) x/-5i 0x0000000000400580
435 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
436 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
437 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
438 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
439 0x40057b <main(int, char**)+25>:
440 callq 0x400536 <Func1(int, char const*)>
442 * Fortran: Support structures with fields of dynamic types and
443 arrays of dynamic types.
445 * The symbol dumping maintenance commands have new syntax.
446 maint print symbols [-pc address] [--] [filename]
447 maint print symbols [-objfile objfile] [-source source] [--] [filename]
448 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
449 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
450 maint print msymbols [-objfile objfile] [--] [filename]
452 * GDB now supports multibit bitfields and enums in target register
455 * New Python-based convenience function $_as_string(val), which returns
456 the textual representation of a value. This function is especially
457 useful to obtain the text label of an enum value.
459 * Intel MPX bound violation handling.
461 Segmentation faults caused by a Intel MPX boundary violation
462 now display the kind of violation (upper or lower), the memory
463 address accessed and the memory bounds, along with the usual
464 signal received and code location.
468 Program received signal SIGSEGV, Segmentation fault
469 Upper bound violation while accessing address 0x7fffffffc3b3
470 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
471 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
473 * Rust language support.
474 GDB now supports debugging programs written in the Rust programming
475 language. See https://www.rust-lang.org/ for more information about
478 * Support for running interpreters on specified input/output devices
480 GDB now supports a new mechanism that allows frontends to provide
481 fully featured GDB console views, as a better alternative to
482 building such views on top of the "-interpreter-exec console"
483 command. See the new "new-ui" command below. With that command,
484 frontends can now start GDB in the traditional command-line mode
485 running in an embedded terminal emulator widget, and create a
486 separate MI interpreter running on a specified i/o device. In this
487 way, GDB handles line editing, history, tab completion, etc. in the
488 console all by itself, and the GUI uses the separate MI interpreter
489 for its own control and synchronization, invisible to the command
492 * The "catch syscall" command catches groups of related syscalls.
494 The "catch syscall" command now supports catching a group of related
495 syscalls using the 'group:' or 'g:' prefix.
500 skip -gfile file-glob-pattern
501 skip -function function
502 skip -rfunction regular-expression
503 A generalized form of the skip command, with new support for
504 glob-style file names and regular expressions for function names.
505 Additionally, a file spec and a function spec may now be combined.
507 maint info line-table REGEXP
508 Display the contents of GDB's internal line table data struture.
511 Run any GDB unit tests that were compiled in.
514 Start a new user interface instance running INTERP as interpreter,
515 using the TTY file for input/output.
519 ** gdb.Breakpoint objects have a new attribute "pending", which
520 indicates whether the breakpoint is pending.
521 ** Three new breakpoint-related events have been added:
522 gdb.breakpoint_created, gdb.breakpoint_modified, and
523 gdb.breakpoint_deleted.
526 Signal ("set") the given MS-Windows event object. This is used in
527 conjunction with the Windows JIT debugging (AeDebug) support, where
528 the OS suspends a crashing process until a debugger can attach to
529 it. Resuming the crashing process, in order to debug it, is done by
532 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
533 was added in GDBserver, including JIT compiling fast tracepoint's
534 conditional expression bytecode into native code.
536 * Support for various remote target protocols and ROM monitors has
539 target m32rsdi Remote M32R debugging over SDI
540 target mips MIPS remote debugging protocol
541 target pmon PMON ROM monitor
542 target ddb NEC's DDB variant of PMON for Vr4300
543 target rockhopper NEC RockHopper variant of PMON
544 target lsi LSI variant of PMO
546 * Support for tracepoints and fast tracepoints on powerpc-linux,
547 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
548 including JIT compiling fast tracepoint's conditional expression
549 bytecode into native code.
551 * MI async record =record-started now includes the method and format used for
552 recording. For example:
554 =record-started,thread-group="i1",method="btrace",format="bts"
556 * MI async record =thread-selected now includes the frame field. For example:
558 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
562 Andes NDS32 nds32*-*-elf
564 *** Changes in GDB 7.11
566 * GDB now supports debugging kernel-based threads on FreeBSD.
568 * Per-inferior thread numbers
570 Thread numbers are now per inferior instead of global. If you're
571 debugging multiple inferiors, GDB displays thread IDs using a
572 qualified INF_NUM.THR_NUM form. For example:
576 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
577 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
578 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
579 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
581 As consequence, thread numbers as visible in the $_thread
582 convenience variable and in Python's InferiorThread.num attribute
583 are no longer unique between inferiors.
585 GDB now maintains a second thread ID per thread, referred to as the
586 global thread ID, which is the new equivalent of thread numbers in
587 previous releases. See also $_gthread below.
589 For backwards compatibility, MI's thread IDs always refer to global
592 * Commands that accept thread IDs now accept the qualified
593 INF_NUM.THR_NUM form as well. For example:
596 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
599 * In commands that accept a list of thread IDs, you can now refer to
600 all threads of an inferior using a star wildcard. GDB accepts
601 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
602 refer to all threads of the current inferior. For example, "info
605 * You can use "info threads -gid" to display the global thread ID of
608 * The new convenience variable $_gthread holds the global number of
611 * The new convenience variable $_inferior holds the number of the
614 * GDB now displays the ID and name of the thread that hit a breakpoint
615 or received a signal, if your program is multi-threaded. For
618 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
619 Thread 1 "main" received signal SIGINT, Interrupt.
621 * Record btrace now supports non-stop mode.
623 * Support for tracepoints on aarch64-linux was added in GDBserver.
625 * The 'record instruction-history' command now indicates speculative execution
626 when using the Intel Processor Trace recording format.
628 * GDB now allows users to specify explicit locations, bypassing
629 the linespec parser. This feature is also available to GDB/MI
632 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
633 GDB now is able to debug both AArch64 applications and ARM applications
636 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
637 including JIT compiling fast tracepoint's conditional expression bytecode
640 * GDB now supports displaced stepping on AArch64 GNU/Linux.
642 * "info threads", "info inferiors", "info display", "info checkpoints"
643 and "maint info program-spaces" now list the corresponding items in
644 ascending ID order, for consistency with all other "info" commands.
646 * In Ada, the overloads selection menu has been enhanced to display the
647 parameter types and the return types for the matching overloaded subprograms.
651 maint set target-non-stop (on|off|auto)
652 maint show target-non-stop
653 Control whether GDB targets always operate in non-stop mode even if
654 "set non-stop" is "off". The default is "auto", meaning non-stop
655 mode is enabled if supported by the target.
657 maint set bfd-sharing
658 maint show bfd-sharing
659 Control the reuse of bfd objects.
663 Control display of debugging info regarding bfd caching.
667 Control display of debugging info regarding FreeBSD threads.
669 set remote multiprocess-extensions-packet
670 show remote multiprocess-extensions-packet
671 Set/show the use of the remote protocol multiprocess extensions.
673 set remote thread-events
674 show remote thread-events
675 Set/show the use of thread create/exit events.
677 set ada print-signatures on|off
678 show ada print-signatures"
679 Control whether parameter types and return types are displayed in overloads
680 selection menus. It is activaled (@code{on}) by default.
684 Controls the maximum size of memory, in bytes, that GDB will
685 allocate for value contents. Prevents incorrect programs from
686 causing GDB to allocate overly large buffers. Default is 64k.
688 * The "disassemble" command accepts a new modifier: /s.
689 It prints mixed source+disassembly like /m with two differences:
690 - disassembled instructions are now printed in program order, and
691 - and source for all relevant files is now printed.
692 The "/m" option is now considered deprecated: its "source-centric"
693 output hasn't proved useful in practice.
695 * The "record instruction-history" command accepts a new modifier: /s.
696 It behaves exactly like /m and prints mixed source+disassembly.
698 * The "set scheduler-locking" command supports a new mode "replay".
699 It behaves like "off" in record mode and like "on" in replay mode.
701 * Support for various ROM monitors has been removed:
703 target dbug dBUG ROM monitor for Motorola ColdFire
704 target picobug Motorola picobug monitor
705 target dink32 DINK32 ROM monitor for PowerPC
706 target m32r Renesas M32R/D ROM monitor
707 target mon2000 mon2000 ROM monitor
708 target ppcbug PPCBUG ROM monitor for PowerPC
710 * Support for reading/writing memory and extracting values on architectures
711 whose memory is addressable in units of any integral multiple of 8 bits.
714 Allows to break when an Ada exception is handled.
719 Indicates that an exec system call was executed.
721 exec-events feature in qSupported
722 The qSupported packet allows GDB to request support for exec
723 events using the new 'gdbfeature' exec-event, and the qSupported
724 response can contain the corresponding 'stubfeature'. Set and
725 show commands can be used to display whether these features are enabled.
728 Equivalent to interrupting with the ^C character, but works in
731 thread created stop reason (T05 create:...)
732 Indicates that the thread was just created and is stopped at entry.
734 thread exit stop reply (w exitcode;tid)
735 Indicates that the thread has terminated.
738 Enables/disables thread create and exit event reporting. For
739 example, this is used in non-stop mode when GDB stops a set of
740 threads and synchronously waits for the their corresponding stop
741 replies. Without exit events, if one of the threads exits, GDB
742 would hang forever not knowing that it should no longer expect a
743 stop for that same thread.
746 Indicates that there are no resumed threads left in the target (all
747 threads are stopped). The remote stub reports support for this stop
748 reply to GDB's qSupported query.
751 Enables/disables catching syscalls from the inferior process.
752 The remote stub reports support for this packet to GDB's qSupported query.
754 syscall_entry stop reason
755 Indicates that a syscall was just called.
757 syscall_return stop reason
758 Indicates that a syscall just returned.
760 * Extended-remote exec events
762 ** GDB now has support for exec events on extended-remote Linux targets.
763 For such targets with Linux kernels 2.5.46 and later, this enables
764 follow-exec-mode and exec catchpoints.
766 set remote exec-event-feature-packet
767 show remote exec-event-feature-packet
768 Set/show the use of the remote exec event feature.
770 * Thread names in remote protocol
772 The reply to qXfer:threads:read may now include a name attribute for each
775 * Target remote mode fork and exec events
777 ** GDB now has support for fork and exec events on target remote mode
778 Linux targets. For such targets with Linux kernels 2.5.46 and later,
779 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
780 fork and exec catchpoints.
782 * Remote syscall events
784 ** GDB now has support for catch syscall on remote Linux targets,
785 currently enabled on x86/x86_64 architectures.
787 set remote catch-syscall-packet
788 show remote catch-syscall-packet
789 Set/show the use of the remote catch syscall feature.
793 ** The -var-set-format command now accepts the zero-hexadecimal
794 format. It outputs data in hexadecimal format with zero-padding on the
799 ** gdb.InferiorThread objects have a new attribute "global_num",
800 which refers to the thread's global thread ID. The existing
801 "num" attribute now refers to the thread's per-inferior number.
802 See "Per-inferior thread numbers" above.
803 ** gdb.InferiorThread objects have a new attribute "inferior", which
804 is the Inferior object the thread belongs to.
806 *** Changes in GDB 7.10
808 * Support for process record-replay and reverse debugging on aarch64*-linux*
809 targets has been added. GDB now supports recording of A64 instruction set
810 including advance SIMD instructions.
812 * Support for Sun's version of the "stabs" debug file format has been removed.
814 * GDB now honors the content of the file /proc/PID/coredump_filter
815 (PID is the process ID) on GNU/Linux systems. This file can be used
816 to specify the types of memory mappings that will be included in a
817 corefile. For more information, please refer to the manual page of
818 "core(5)". GDB also has a new command: "set use-coredump-filter
819 on|off". It allows to set whether GDB will read the content of the
820 /proc/PID/coredump_filter file when generating a corefile.
822 * The "info os" command on GNU/Linux can now display information on
824 "info os cpus" Listing of all cpus/cores on the system
826 * GDB has two new commands: "set serial parity odd|even|none" and
827 "show serial parity". These allows to set or show parity for the
830 * The "info source" command now displays the producer string if it was
831 present in the debug info. This typically includes the compiler version
832 and may include things like its command line arguments.
834 * The "info dll", an alias of the "info sharedlibrary" command,
835 is now available on all platforms.
837 * Directory names supplied to the "set sysroot" commands may be
838 prefixed with "target:" to tell GDB to access shared libraries from
839 the target system, be it local or remote. This replaces the prefix
840 "remote:". The default sysroot has been changed from "" to
841 "target:". "remote:" is automatically converted to "target:" for
842 backward compatibility.
844 * The system root specified by "set sysroot" will be prepended to the
845 filename of the main executable (if reported to GDB as absolute by
846 the operating system) when starting processes remotely, and when
847 attaching to already-running local or remote processes.
849 * GDB now supports automatic location and retrieval of executable
850 files from remote targets. Remote debugging can now be initiated
851 using only a "target remote" or "target extended-remote" command
852 (no "set sysroot" or "file" commands are required). See "New remote
855 * The "dump" command now supports verilog hex format.
857 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
859 * On GNU/Linux, GDB and gdbserver are now able to access executable
860 and shared library files without a "set sysroot" command when
861 attaching to processes running in different mount namespaces from
862 the debugger. This makes it possible to attach to processes in
863 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
864 See "New remote packets" below.
866 * The "tui reg" command now provides completion for all of the
867 available register groups, including target specific groups.
869 * The HISTSIZE environment variable is no longer read when determining
870 the size of GDB's command history. GDB now instead reads the dedicated
871 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
872 disables truncation of command history. Non-numeric values of GDBHISTSIZE
877 ** Memory ports can now be unbuffered.
881 ** gdb.Objfile objects have a new attribute "username",
882 which is the name of the objfile as specified by the user,
883 without, for example, resolving symlinks.
884 ** You can now write frame unwinders in Python.
885 ** gdb.Type objects have a new method "optimized_out",
886 returning optimized out gdb.Value instance of this type.
887 ** gdb.Value objects have new methods "reference_value" and
888 "const_value" which return a reference to the value and a
889 "const" version of the value respectively.
893 maint print symbol-cache
894 Print the contents of the symbol cache.
896 maint print symbol-cache-statistics
897 Print statistics of symbol cache usage.
899 maint flush-symbol-cache
900 Flush the contents of the symbol cache.
904 Start branch trace recording using Branch Trace Store (BTS) format.
907 Evaluate expression by using the compiler and print result.
911 Explicit commands for enabling and disabling tui mode.
914 set mpx bound on i386 and amd64
915 Support for bound table investigation on Intel MPX enabled applications.
919 Start branch trace recording using Intel Processor Trace format.
922 Print information about branch tracing internals.
924 maint btrace packet-history
925 Print the raw branch tracing data.
927 maint btrace clear-packet-history
928 Discard the stored raw branch tracing data.
931 Discard all branch tracing data. It will be fetched and processed
932 anew by the next "record" command.
937 Renamed from "set debug dwarf2-die".
939 Renamed from "show debug dwarf2-die".
942 Renamed from "set debug dwarf2-read".
943 show debug dwarf-read
944 Renamed from "show debug dwarf2-read".
946 maint set dwarf always-disassemble
947 Renamed from "maint set dwarf2 always-disassemble".
948 maint show dwarf always-disassemble
949 Renamed from "maint show dwarf2 always-disassemble".
951 maint set dwarf max-cache-age
952 Renamed from "maint set dwarf2 max-cache-age".
953 maint show dwarf max-cache-age
954 Renamed from "maint show dwarf2 max-cache-age".
957 show debug dwarf-line
958 Control display of debugging info regarding DWARF line processing.
962 Set the maximum number of candidates to be considered during
963 completion. The default value is 200. This limit allows GDB
964 to avoid generating large completion lists, the computation of
965 which can cause the debugger to become temporarily unresponsive.
967 set history remove-duplicates
968 show history remove-duplicates
969 Control the removal of duplicate history entries.
971 maint set symbol-cache-size
972 maint show symbol-cache-size
973 Control the size of the symbol cache.
975 set|show record btrace bts buffer-size
976 Set and show the size of the ring buffer used for branch tracing in
978 The obtained size may differ from the requested size. Use "info
979 record" to see the obtained buffer size.
981 set debug linux-namespaces
982 show debug linux-namespaces
983 Control display of debugging info regarding Linux namespaces.
985 set|show record btrace pt buffer-size
986 Set and show the size of the ring buffer used for branch tracing in
987 Intel Processor Trace format.
988 The obtained size may differ from the requested size. Use "info
989 record" to see the obtained buffer size.
991 maint set|show btrace pt skip-pad
992 Set and show whether PAD packets are skipped when computing the
995 * The command 'thread apply all' can now support new option '-ascending'
996 to call its specified command for all threads in ascending order.
998 * Python/Guile scripting
1000 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1001 special section named `.debug_gdb_scripts'.
1003 * New remote packets
1005 qXfer:btrace-conf:read
1006 Return the branch trace configuration for the current thread.
1008 Qbtrace-conf:bts:size
1009 Set the requested ring buffer size for branch tracing in BTS format.
1012 Enable Intel Procesor Trace-based branch tracing for the current
1013 process. The remote stub reports support for this packet to GDB's
1016 Qbtrace-conf:pt:size
1017 Set the requested ring buffer size for branch tracing in Intel Processor
1021 Indicates a memory breakpoint instruction was executed, irrespective
1022 of whether it was GDB that planted the breakpoint or the breakpoint
1023 is hardcoded in the program. This is required for correct non-stop
1027 Indicates the target stopped for a hardware breakpoint. This is
1028 required for correct non-stop mode operation.
1031 Return information about files on the remote system.
1033 qXfer:exec-file:read
1034 Return the full absolute name of the file that was executed to
1035 create a process running on the remote system.
1038 Select the filesystem on which vFile: operations with filename
1039 arguments will operate. This is required for GDB to be able to
1040 access files on remote targets where the remote stub does not
1041 share a common filesystem with the inferior(s).
1044 Indicates that a fork system call was executed.
1047 Indicates that a vfork system call was executed.
1049 vforkdone stop reason
1050 Indicates that a vfork child of the specified process has executed
1051 an exec or exit, allowing the vfork parent to resume execution.
1053 fork-events and vfork-events features in qSupported
1054 The qSupported packet allows GDB to request support for fork and
1055 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1056 and the qSupported response can contain the corresponding
1057 'stubfeatures'. Set and show commands can be used to display
1058 whether these features are enabled.
1060 * Extended-remote fork events
1062 ** GDB now has support for fork events on extended-remote Linux
1063 targets. For targets with Linux kernels 2.5.60 and later, this
1064 enables follow-fork-mode and detach-on-fork for both fork and
1065 vfork, as well as fork and vfork catchpoints.
1067 * The info record command now shows the recording format and the
1068 branch tracing configuration for the current thread when using
1069 the btrace record target.
1070 For the BTS format, it shows the ring buffer size.
1072 * GDB now has support for DTrace USDT (Userland Static Defined
1073 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1075 * GDB now supports access to vector registers on S/390 GNU/Linux
1078 * Removed command line options
1080 -xdb HP-UX XDB compatibility mode.
1082 * Removed targets and native configurations
1084 HP/PA running HP-UX hppa*-*-hpux*
1085 Itanium running HP-UX ia64-*-hpux*
1087 * New configure options
1090 This configure option allows the user to build GDB with support for
1091 Intel Processor Trace (default: auto). This requires libipt.
1093 --with-libipt-prefix=PATH
1094 Specify the path to the version of libipt that GDB should use.
1095 $PATH/include should contain the intel-pt.h header and
1096 $PATH/lib should contain the libipt.so library.
1098 *** Changes in GDB 7.9.1
1102 ** Xmethods can now specify a result type.
1104 *** Changes in GDB 7.9
1106 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1110 ** You can now access frame registers from Python scripts.
1111 ** New attribute 'producer' for gdb.Symtab objects.
1112 ** gdb.Objfile objects have a new attribute "progspace",
1113 which is the gdb.Progspace object of the containing program space.
1114 ** gdb.Objfile objects have a new attribute "owner".
1115 ** gdb.Objfile objects have a new attribute "build_id",
1116 which is the build ID generated when the file was built.
1117 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1118 ** A new event "gdb.clear_objfiles" has been added, triggered when
1119 selecting a new file to debug.
1120 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1121 ** New function gdb.lookup_objfile.
1123 New events which are triggered when GDB modifies the state of the
1126 ** gdb.events.inferior_call_pre: Function call is about to be made.
1127 ** gdb.events.inferior_call_post: Function call has just been made.
1128 ** gdb.events.memory_changed: A memory location has been altered.
1129 ** gdb.events.register_changed: A register has been altered.
1131 * New Python-based convenience functions:
1133 ** $_caller_is(name [, number_of_frames])
1134 ** $_caller_matches(regexp [, number_of_frames])
1135 ** $_any_caller_is(name [, number_of_frames])
1136 ** $_any_caller_matches(regexp [, number_of_frames])
1138 * GDB now supports the compilation and injection of source code into
1139 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1140 to compile the source code to object code, and if successful, inject
1141 and execute that code within the current context of the inferior.
1142 Currently the C language is supported. The commands used to
1143 interface with this new feature are:
1145 compile code [-raw|-r] [--] [source code]
1146 compile file [-raw|-r] filename
1150 demangle [-l language] [--] name
1151 Demangle "name" in the specified language, or the current language
1152 if elided. This command is renamed from the "maint demangle" command.
1153 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1154 as "maint demangler-warning".
1156 queue-signal signal-name-or-number
1157 Queue a signal to be delivered to the thread when it is resumed.
1159 add-auto-load-scripts-directory directory
1160 Add entries to the list of directories from which to load auto-loaded
1163 maint print user-registers
1164 List all currently available "user" registers.
1166 compile code [-r|-raw] [--] [source code]
1167 Compile, inject, and execute in the inferior the executable object
1168 code produced by compiling the provided source code.
1170 compile file [-r|-raw] filename
1171 Compile and inject into the inferior the executable object code
1172 produced by compiling the source code stored in the filename
1175 * On resume, GDB now always passes the signal the program had stopped
1176 for to the thread the signal was sent to, even if the user changed
1177 threads before resuming. Previously GDB would often (but not
1178 always) deliver the signal to the thread that happens to be current
1181 * Conversely, the "signal" command now consistently delivers the
1182 requested signal to the current thread. GDB now asks for
1183 confirmation if the program had stopped for a signal and the user
1184 switched threads meanwhile.
1186 * "breakpoint always-inserted" modes "off" and "auto" merged.
1188 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1189 won't remove breakpoints from the target until all threads stop,
1190 even in non-stop mode. The "auto" mode has been removed, and "off"
1191 is now the default mode.
1195 set debug symbol-lookup
1196 show debug symbol-lookup
1197 Control display of debugging info regarding symbol lookup.
1201 ** The -list-thread-groups command outputs an exit-code field for
1202 inferiors that have exited.
1206 MIPS SDE mips*-sde*-elf*
1210 Support for these obsolete configurations has been removed.
1212 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1213 SGI Irix-5.x mips-*-irix5*
1214 SGI Irix-6.x mips-*-irix6*
1215 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1216 VAX running Ultrix vax-*-ultrix*
1218 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1219 and "assf"), have been removed. Use the "sharedlibrary" command, or
1220 its alias "share", instead.
1222 *** Changes in GDB 7.8
1224 * New command line options
1227 This is an alias for the --data-directory option.
1229 * GDB supports printing and modifying of variable length automatic arrays
1230 as specified in ISO C99.
1232 * The ARM simulator now supports instruction level tracing
1233 with or without disassembly.
1237 GDB now has support for scripting using Guile. Whether this is
1238 available is determined at configure time.
1239 Guile version 2.0 or greater is required.
1240 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1242 * New commands (for set/show, see "New options" below)
1246 Invoke CODE by passing it to the Guile interpreter.
1250 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1252 info auto-load guile-scripts [regexp]
1253 Print the list of automatically loaded Guile scripts.
1255 * The source command is now capable of sourcing Guile scripts.
1256 This feature is dependent on the debugger being built with Guile support.
1260 set print symbol-loading (off|brief|full)
1261 show print symbol-loading
1262 Control whether to print informational messages when loading symbol
1263 information for a file. The default is "full", but when debugging
1264 programs with large numbers of shared libraries the amount of output
1265 becomes less useful.
1267 set guile print-stack (none|message|full)
1268 show guile print-stack
1269 Show a stack trace when an error is encountered in a Guile script.
1271 set auto-load guile-scripts (on|off)
1272 show auto-load guile-scripts
1273 Control auto-loading of Guile script files.
1275 maint ada set ignore-descriptive-types (on|off)
1276 maint ada show ignore-descriptive-types
1277 Control whether the debugger should ignore descriptive types in Ada
1278 programs. The default is not to ignore the descriptive types. See
1279 the user manual for more details on descriptive types and the intended
1280 usage of this option.
1282 set auto-connect-native-target
1284 Control whether GDB is allowed to automatically connect to the
1285 native target for the run, attach, etc. commands when not connected
1286 to any target yet. See also "target native" below.
1288 set record btrace replay-memory-access (read-only|read-write)
1289 show record btrace replay-memory-access
1290 Control what memory accesses are allowed during replay.
1292 maint set target-async (on|off)
1293 maint show target-async
1294 This controls whether GDB targets operate in synchronous or
1295 asynchronous mode. Normally the default is asynchronous, if it is
1296 available; but this can be changed to more easily debug problems
1297 occurring only in synchronous mode.
1299 set mi-async (on|off)
1301 Control whether MI asynchronous mode is preferred. This supersedes
1302 "set target-async" of previous GDB versions.
1304 * "set target-async" is deprecated as a CLI option and is now an alias
1305 for "set mi-async" (only puts MI into async mode).
1307 * Background execution commands (e.g., "c&", "s&", etc.) are now
1308 possible ``out of the box'' if the target supports them. Previously
1309 the user would need to explicitly enable the possibility with the
1310 "set target-async on" command.
1312 * New features in the GDB remote stub, GDBserver
1314 ** New option --debug-format=option1[,option2,...] allows one to add
1315 additional text to each output. At present only timestamps
1316 are supported: --debug-format=timestamps.
1317 Timestamps can also be turned on with the
1318 "monitor set debug-format timestamps" command from GDB.
1320 * The 'record instruction-history' command now starts counting instructions
1321 at one. This also affects the instruction ranges reported by the
1322 'record function-call-history' command when given the /i modifier.
1324 * The command 'record function-call-history' supports a new modifier '/c' to
1325 indent the function names based on their call stack depth.
1326 The fields for the '/i' and '/l' modifier have been reordered.
1327 The source line range is now prefixed with 'at'.
1328 The instruction range is now prefixed with 'inst'.
1329 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1330 "record instruction-history" and "list" commands.
1332 * The ranges given as arguments to the 'record function-call-history' and
1333 'record instruction-history' commands are now inclusive.
1335 * The btrace record target now supports the 'record goto' command.
1336 For locations inside the execution trace, the back trace is computed
1337 based on the information stored in the execution trace.
1339 * The btrace record target supports limited reverse execution and replay.
1340 The target does not record data and therefore does not allow reading
1341 memory or registers.
1343 * The "catch syscall" command now works on s390*-linux* targets.
1345 * The "compare-sections" command is no longer specific to target
1346 remote. It now works with all targets.
1348 * All native targets are now consistently called "native".
1349 Consequently, the "target child", "target GNU", "target djgpp",
1350 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1351 commands have been replaced with "target native". The QNX/NTO port
1352 leaves the "procfs" target in place and adds a "native" target for
1353 consistency with other ports. The impact on users should be minimal
1354 as these commands previously either throwed an error, or were
1355 no-ops. The target's name is visible in the output of the following
1356 commands: "help target", "info target", "info files", "maint print
1359 * The "target native" command now connects to the native target. This
1360 can be used to launch native programs even when "set
1361 auto-connect-native-target" is set to off.
1363 * GDB now supports access to Intel MPX registers on GNU/Linux.
1365 * Support for Intel AVX-512 registers on GNU/Linux.
1366 Support displaying and modifying Intel AVX-512 registers
1367 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1369 * New remote packets
1371 qXfer:btrace:read's annex
1372 The qXfer:btrace:read packet supports a new annex 'delta' to read
1373 branch trace incrementally.
1377 ** Valid Python operations on gdb.Value objects representing
1378 structs/classes invoke the corresponding overloaded operators if
1380 ** New `Xmethods' feature in the Python API. Xmethods are
1381 additional methods or replacements for existing methods of a C++
1382 class. This feature is useful for those cases where a method
1383 defined in C++ source code could be inlined or optimized out by
1384 the compiler, making it unavailable to GDB.
1387 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1389 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1390 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1391 its alias "share", instead.
1393 * The commands "set remotebaud" and "show remotebaud" are no longer
1394 supported. Use "set serial baud" and "show serial baud" (respectively)
1399 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1400 target-async". The latter is left as a deprecated alias of the
1401 former for backward compatibility. If the target supports it,
1402 CLI background execution commands are now always possible by
1403 default, independently of whether the frontend stated a
1404 preference for asynchronous execution with "-gdb-set mi-async".
1405 Previously "-gdb-set target-async off" affected both MI execution
1406 commands and CLI execution commands.
1408 *** Changes in GDB 7.7
1410 * Improved support for process record-replay and reverse debugging on
1411 arm*-linux* targets. Support for thumb32 and syscall instruction
1412 recording has been added.
1414 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1416 * GDB now supports Fission DWP file format version 2.
1417 http://gcc.gnu.org/wiki/DebugFission
1419 * New convenience function "$_isvoid", to check whether an expression
1420 is void. A void expression is an expression where the type of the
1421 result is "void". For example, some convenience variables may be
1422 "void" when evaluated (e.g., "$_exitcode" before the execution of
1423 the program being debugged; or an undefined convenience variable).
1424 Another example, when calling a function whose return type is
1427 * The "maintenance print objfiles" command now takes an optional regexp.
1429 * The "catch syscall" command now works on arm*-linux* targets.
1431 * GDB now consistently shows "<not saved>" when printing values of
1432 registers the debug info indicates have not been saved in the frame
1433 and there's nowhere to retrieve them from
1434 (callee-saved/call-clobbered registers):
1439 (gdb) info registers rax
1442 Before, the former would print "<optimized out>", and the latter
1443 "*value not available*".
1445 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1450 ** Frame filters and frame decorators have been added.
1451 ** Temporary breakpoints are now supported.
1452 ** Line tables representation has been added.
1453 ** New attribute 'parent_type' for gdb.Field objects.
1454 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1455 ** New attribute 'name' for gdb.Type objects.
1459 Nios II ELF nios2*-*-elf
1460 Nios II GNU/Linux nios2*-*-linux
1461 Texas Instruments MSP430 msp430*-*-elf
1463 * Removed native configurations
1465 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1466 been removed. ELF variants of these configurations are kept supported.
1468 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1469 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1470 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1471 i[34567]86-*-openbsd3.[0-3]
1472 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1473 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1474 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1478 Like "catch throw", but catches a re-thrown exception.
1479 maint check-psymtabs
1480 Renamed from old "maint check-symtabs".
1482 Perform consistency checks on symtabs.
1483 maint expand-symtabs
1484 Expand symtabs matching an optional regexp.
1487 Display the details of GDB configure-time options.
1489 maint set|show per-command
1490 maint set|show per-command space
1491 maint set|show per-command time
1492 maint set|show per-command symtab
1493 Enable display of per-command gdb resource usage.
1495 remove-symbol-file FILENAME
1496 remove-symbol-file -a ADDRESS
1497 Remove a symbol file added via add-symbol-file. The file to remove
1498 can be identified by its filename or by an address that lies within
1499 the boundaries of this symbol file in memory.
1502 info exceptions REGEXP
1503 Display the list of Ada exceptions defined in the program being
1504 debugged. If provided, only the exceptions whose names match REGEXP
1509 set debug symfile off|on
1511 Control display of debugging info regarding reading symbol files and
1512 symbol tables within those files
1514 set print raw frame-arguments
1515 show print raw frame-arguments
1516 Set/show whether to print frame arguments in raw mode,
1517 disregarding any defined pretty-printers.
1519 set remote trace-status-packet
1520 show remote trace-status-packet
1521 Set/show the use of remote protocol qTStatus packet.
1525 Control display of debugging messages related to Nios II targets.
1529 Control whether target-assisted range stepping is enabled.
1531 set startup-with-shell
1532 show startup-with-shell
1533 Specifies whether Unix child processes are started via a shell or
1538 Use the target memory cache for accesses to the code segment. This
1539 improves performance of remote debugging (particularly disassembly).
1541 * You can now use a literal value 'unlimited' for options that
1542 interpret 0 or -1 as meaning "unlimited". E.g., "set
1543 trace-buffer-size unlimited" is now an alias for "set
1544 trace-buffer-size -1" and "set height unlimited" is now an alias for
1547 * The "set debug symtab-create" debugging option of GDB has been changed to
1548 accept a verbosity level. 0 means "off", 1 provides basic debugging
1549 output, and values of 2 or greater provides more verbose output.
1551 * New command-line options
1553 Display the details of GDB configure-time options.
1555 * The command 'tsave' can now support new option '-ctf' to save trace
1556 buffer in Common Trace Format.
1558 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1561 * GDB now implements the the C++ 'typeid' operator.
1563 * The new convenience variable $_exception holds the exception being
1564 thrown or caught at an exception-related catchpoint.
1566 * The exception-related catchpoints, like "catch throw", now accept a
1567 regular expression which can be used to filter exceptions by type.
1569 * The new convenience variable $_exitsignal is automatically set to
1570 the terminating signal number when the program being debugged dies
1571 due to an uncaught signal.
1575 ** All MI commands now accept an optional "--language" option.
1576 Support for this feature can be verified by using the "-list-features"
1577 command, which should contain "language-option".
1579 ** The new command -info-gdb-mi-command allows the user to determine
1580 whether a GDB/MI command is supported or not.
1582 ** The "^error" result record returned when trying to execute an undefined
1583 GDB/MI command now provides a variable named "code" whose content is the
1584 "undefined-command" error code. Support for this feature can be verified
1585 by using the "-list-features" command, which should contain
1586 "undefined-command-error-code".
1588 ** The -trace-save MI command can optionally save trace buffer in Common
1591 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1593 ** The command -data-list-register-values now accepts an optional
1594 "--skip-unavailable" option. When used, only the available registers
1597 ** The new command -trace-frame-collected dumps collected variables,
1598 computed expressions, tvars, memory and registers in a traceframe.
1600 ** The commands -stack-list-locals, -stack-list-arguments and
1601 -stack-list-variables now accept an option "--skip-unavailable".
1602 When used, only the available locals or arguments are displayed.
1604 ** The -exec-run command now accepts an optional "--start" option.
1605 When used, the command follows the same semantics as the "start"
1606 command, stopping the program's execution at the start of its
1607 main subprogram. Support for this feature can be verified using
1608 the "-list-features" command, which should contain
1609 "exec-run-start-option".
1611 ** The new commands -catch-assert and -catch-exceptions insert
1612 catchpoints stopping the program when Ada exceptions are raised.
1614 ** The new command -info-ada-exceptions provides the equivalent of
1615 the new "info exceptions" command.
1617 * New system-wide configuration scripts
1618 A GDB installation now provides scripts suitable for use as system-wide
1619 configuration scripts for the following systems:
1623 * GDB now supports target-assigned range stepping with remote targets.
1624 This improves the performance of stepping source lines by reducing
1625 the number of control packets from/to GDB. See "New remote packets"
1628 * GDB now understands the element 'tvar' in the XML traceframe info.
1629 It has the id of the collected trace state variables.
1631 * On S/390 targets that provide the transactional-execution feature,
1632 the program interruption transaction diagnostic block (TDB) is now
1633 represented as a number of additional "registers" in GDB.
1635 * New remote packets
1639 The vCont packet supports a new 'r' action, that tells the remote
1640 stub to step through an address range itself, without GDB
1641 involvemement at each single-step.
1643 qXfer:libraries-svr4:read's annex
1644 The previously unused annex of the qXfer:libraries-svr4:read packet
1645 is now used to support passing an argument list. The remote stub
1646 reports support for this argument list to GDB's qSupported query.
1647 The defined arguments are "start" and "prev", used to reduce work
1648 necessary for library list updating, resulting in significant
1651 * New features in the GDB remote stub, GDBserver
1653 ** GDBserver now supports target-assisted range stepping. Currently
1654 enabled on x86/x86_64 GNU/Linux targets.
1656 ** GDBserver now adds element 'tvar' in the XML in the reply to
1657 'qXfer:traceframe-info:read'. It has the id of the collected
1658 trace state variables.
1660 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1663 * New 'z' formatter for printing and examining memory, this displays the
1664 value as hexadecimal zero padded on the left to the size of the type.
1666 * GDB can now use Windows x64 unwinding data.
1668 * The "set remotebaud" command has been replaced by "set serial baud".
1669 Similarly, "show remotebaud" has been replaced by "show serial baud".
1670 The "set remotebaud" and "show remotebaud" commands are still available
1671 to provide backward compatibility with older versions of GDB.
1673 *** Changes in GDB 7.6
1675 * Target record has been renamed to record-full.
1676 Record/replay is now enabled with the "record full" command.
1677 This also affects settings that are associated with full record/replay
1678 that have been moved from "set/show record" to "set/show record full":
1680 set|show record full insn-number-max
1681 set|show record full stop-at-limit
1682 set|show record full memory-query
1684 * A new record target "record-btrace" has been added. The new target
1685 uses hardware support to record the control-flow of a process. It
1686 does not support replaying the execution, but it implements the
1687 below new commands for investigating the recorded execution log.
1688 This new recording method can be enabled using:
1692 The "record-btrace" target is only available on Intel Atom processors
1693 and requires a Linux kernel 2.6.32 or later.
1695 * Two new commands have been added for record/replay to give information
1696 about the recorded execution without having to replay the execution.
1697 The commands are only supported by "record btrace".
1699 record instruction-history prints the execution history at
1700 instruction granularity
1702 record function-call-history prints the execution history at
1703 function granularity
1705 * New native configurations
1707 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1708 FreeBSD/powerpc powerpc*-*-freebsd
1709 x86_64/Cygwin x86_64-*-cygwin*
1710 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1714 ARM AArch64 aarch64*-*-elf
1715 ARM AArch64 GNU/Linux aarch64*-*-linux
1716 Lynx 178 PowerPC powerpc-*-lynx*178
1717 x86_64/Cygwin x86_64-*-cygwin*
1718 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1720 * If the configured location of system.gdbinit file (as given by the
1721 --with-system-gdbinit option at configure time) is in the
1722 data-directory (as specified by --with-gdb-datadir at configure
1723 time) or in one of its subdirectories, then GDB will look for the
1724 system-wide init file in the directory specified by the
1725 --data-directory command-line option.
1727 * New command line options:
1729 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1730 other initialization files, unlike -nx which disables all of them.
1732 * Removed command line options
1734 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1737 * The 'ptype' and 'whatis' commands now accept an argument to control
1740 * 'info proc' now works on some core files.
1744 ** Vectors can be created with gdb.Type.vector.
1746 ** Python's atexit.register now works in GDB.
1748 ** Types can be pretty-printed via a Python API.
1750 ** Python 3 is now supported (in addition to Python 2.4 or later)
1752 ** New class gdb.Architecture exposes GDB's internal representation
1753 of architecture in the Python API.
1755 ** New method Frame.architecture returns the gdb.Architecture object
1756 corresponding to the frame's architecture.
1758 * New Python-based convenience functions:
1760 ** $_memeq(buf1, buf2, length)
1761 ** $_streq(str1, str2)
1763 ** $_regex(str, regex)
1765 * The 'cd' command now defaults to using '~' (the home directory) if not
1768 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1769 default for GCC since November 2000.
1771 * The command 'forward-search' can now be abbreviated as 'fo'.
1773 * The command 'info tracepoints' can now display 'installed on target'
1774 or 'not installed on target' for each non-pending location of tracepoint.
1776 * New configure options
1778 --enable-libmcheck/--disable-libmcheck
1779 By default, development versions are built with -lmcheck on hosts
1780 that support it, in order to help track memory corruption issues.
1781 Release versions, on the other hand, are built without -lmcheck
1782 by default. The --enable-libmcheck/--disable-libmcheck configure
1783 options allow the user to override that default.
1784 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1785 This configure option allows the user to build GDB with
1786 libbabeltrace using which GDB can read Common Trace Format data.
1788 * New commands (for set/show, see "New options" below)
1791 Catch signals. This is similar to "handle", but allows commands and
1792 conditions to be attached.
1795 List the BFDs known to GDB.
1797 python-interactive [command]
1799 Start a Python interactive prompt, or evaluate the optional command
1800 and print the result of expressions.
1803 "py" is a new alias for "python".
1805 enable type-printer [name]...
1806 disable type-printer [name]...
1807 Enable or disable type printers.
1811 ** For the Renesas Super-H architecture, the "regs" command has been removed
1812 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1817 set print type methods (on|off)
1818 show print type methods
1819 Control whether method declarations are displayed by "ptype".
1820 The default is to show them.
1822 set print type typedefs (on|off)
1823 show print type typedefs
1824 Control whether typedef definitions are displayed by "ptype".
1825 The default is to show them.
1827 set filename-display basename|relative|absolute
1828 show filename-display
1829 Control the way in which filenames is displayed.
1830 The default is "relative", which preserves previous behavior.
1832 set trace-buffer-size
1833 show trace-buffer-size
1834 Request target to change the size of trace buffer.
1836 set remote trace-buffer-size-packet auto|on|off
1837 show remote trace-buffer-size-packet
1838 Control the use of the remote protocol `QTBuffer:size' packet.
1842 Control display of debugging messages related to ARM AArch64.
1845 set debug coff-pe-read
1846 show debug coff-pe-read
1847 Control display of debugging messages related to reading of COFF/PE
1852 Control display of debugging messages related to Mach-O symbols
1855 set debug notification
1856 show debug notification
1857 Control display of debugging info for async remote notification.
1861 ** Command parameter changes are now notified using new async record
1862 "=cmd-param-changed".
1863 ** Trace frame changes caused by command "tfind" are now notified using
1864 new async record "=traceframe-changed".
1865 ** The creation, deletion and modification of trace state variables
1866 are now notified using new async records "=tsv-created",
1867 "=tsv-deleted" and "=tsv-modified".
1868 ** The start and stop of process record are now notified using new
1869 async record "=record-started" and "=record-stopped".
1870 ** Memory changes are now notified using new async record
1872 ** The data-disassemble command response will include a "fullname" field
1873 containing the absolute file name when source has been requested.
1874 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
1875 command, to allow pattern filling of memory areas.
1876 ** New commands "-catch-load"/"-catch-unload" added for intercepting
1877 library load/unload events.
1878 ** The response to breakpoint commands and breakpoint async records
1879 includes an "installed" field containing a boolean state about each
1880 non-pending tracepoint location is whether installed on target or not.
1881 ** Output of the "-trace-status" command includes a "trace-file" field
1882 containing the name of the trace file being examined. This field is
1883 optional, and only present when examining a trace file.
1884 ** The "fullname" field is now always present along with the "file" field,
1885 even if the file cannot be found by GDB.
1887 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
1888 You must have the LZMA library available when configuring GDB for this
1889 feature to be enabled. For more information, see:
1890 http://fedoraproject.org/wiki/Features/MiniDebugInfo
1892 * New remote packets
1895 Set the size of trace buffer. The remote stub reports support for this
1896 packet to gdb's qSupported query.
1899 Enable Branch Trace Store (BTS)-based branch tracing for the current
1900 thread. The remote stub reports support for this packet to gdb's
1904 Disable branch tracing for the current thread. The remote stub reports
1905 support for this packet to gdb's qSupported query.
1908 Read the traced branches for the current thread. The remote stub
1909 reports support for this packet to gdb's qSupported query.
1911 *** Changes in GDB 7.5
1913 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
1914 for more x32 ABI info.
1916 * GDB now supports access to MIPS DSP registers on Linux targets.
1918 * GDB now supports debugging microMIPS binaries.
1920 * The "info os" command on GNU/Linux can now display information on
1921 several new classes of objects managed by the operating system:
1922 "info os procgroups" lists process groups
1923 "info os files" lists file descriptors
1924 "info os sockets" lists internet-domain sockets
1925 "info os shm" lists shared-memory regions
1926 "info os semaphores" lists semaphores
1927 "info os msg" lists message queues
1928 "info os modules" lists loaded kernel modules
1930 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
1931 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
1932 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
1933 options and inspect the probe arguments using the new $_probe_arg family
1934 of convenience variables. You can obtain more information about SystemTap
1935 in <http://sourceware.org/systemtap/>.
1937 * GDB now supports reversible debugging on ARM, it allows you to
1938 debug basic ARM and THUMB instructions, and provides
1939 record/replay support.
1941 * The option "symbol-reloading" has been deleted as it is no longer used.
1945 ** GDB commands implemented in Python can now be put in command class
1948 ** The "maint set python print-stack on|off" is now deleted.
1950 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
1951 apply "flag enum"-style pretty-printing to any enum.
1953 ** gdb.lookup_symbol can now work when there is no current frame.
1955 ** gdb.Symbol now has a 'line' attribute, holding the line number in
1956 the source at which the symbol was defined.
1958 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
1959 method 'value'. The former indicates whether the symbol needs a
1960 frame in order to compute its value, and the latter computes the
1963 ** A new method 'referenced_value' on gdb.Value objects which can
1964 dereference pointer as well as C++ reference values.
1966 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
1967 which return the global and static blocks (as gdb.Block objects),
1968 of the underlying symbol table, respectively.
1970 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
1971 object associated with a PC value.
1973 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
1974 of the address range occupied by code for the current source line.
1976 * Go language support.
1977 GDB now supports debugging programs written in the Go programming
1980 * GDBserver now supports stdio connections.
1981 E.g. (gdb) target remote | ssh myhost gdbserver - hello
1983 * The binary "gdbtui" can no longer be built or installed.
1984 Use "gdb -tui" instead.
1986 * GDB will now print "flag" enums specially. A flag enum is one where
1987 all the enumerator values have no bits in common when pairwise
1988 "and"ed. When printing a value whose type is a flag enum, GDB will
1989 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
1990 (gdb) print (enum E) 3
1993 * The filename part of a linespec will now match trailing components
1994 of a source file name. For example, "break gcc/expr.c:1000" will
1995 now set a breakpoint in build/gcc/expr.c, but not
1996 build/libcpp/expr.c.
1998 * The "info proc" and "generate-core-file" commands will now also
1999 work on remote targets connected to GDBserver on Linux.
2001 * The command "info catch" has been removed. It has been disabled
2002 since December 2007.
2004 * The "catch exception" and "catch assert" commands now accept
2005 a condition at the end of the command, much like the "break"
2006 command does. For instance:
2008 (gdb) catch exception Constraint_Error if Barrier = True
2010 Previously, it was possible to add a condition to such catchpoints,
2011 but it had to be done as a second step, after the catchpoint had been
2012 created, using the "condition" command.
2014 * The "info static-tracepoint-marker" command will now also work on
2015 native Linux targets with in-process agent.
2017 * GDB can now set breakpoints on inlined functions.
2019 * The .gdb_index section has been updated to include symbols for
2020 inlined functions. GDB will ignore older .gdb_index sections by
2021 default, which could cause symbol files to be loaded more slowly
2022 until their .gdb_index sections can be recreated. The new command
2023 "set use-deprecated-index-sections on" will cause GDB to use any older
2024 .gdb_index sections it finds. This will restore performance, but the
2025 ability to set breakpoints on inlined functions will be lost in symbol
2026 files with older .gdb_index sections.
2028 The .gdb_index section has also been updated to record more information
2029 about each symbol. This speeds up the "info variables", "info functions"
2030 and "info types" commands when used with programs having the .gdb_index
2031 section, as well as speeding up debugging with shared libraries using
2032 the .gdb_index section.
2034 * Ada support for GDB/MI Variable Objects has been added.
2036 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2041 ** New command -info-os is the MI equivalent of "info os".
2043 ** Output logs ("set logging" and related) now include MI output.
2047 ** "set use-deprecated-index-sections on|off"
2048 "show use-deprecated-index-sections on|off"
2049 Controls the use of deprecated .gdb_index sections.
2051 ** "catch load" and "catch unload" can be used to stop when a shared
2052 library is loaded or unloaded, respectively.
2054 ** "enable count" can be used to auto-disable a breakpoint after
2057 ** "info vtbl" can be used to show the virtual method tables for
2058 C++ and Java objects.
2060 ** "explore" and its sub commands "explore value" and "explore type"
2061 can be used to recursively explore values and types of
2062 expressions. These commands are available only if GDB is
2063 configured with '--with-python'.
2065 ** "info auto-load" shows status of all kinds of auto-loaded files,
2066 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2067 sequences of commands files, "info auto-load python-scripts"
2068 shows status of auto-loading Python script files,
2069 "info auto-load local-gdbinit" shows status of loading init file
2070 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2071 status of inferior specific thread debugging shared library loading.
2073 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2074 and "show auto-load-scripts" commands have been deprecated, use their
2075 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2076 and "show auto-load python-scripts" counterparts instead.
2078 ** "dprintf location,format,args..." creates a dynamic printf, which
2079 is basically a breakpoint that does a printf and immediately
2080 resumes your program's execution, so it is like a printf that you
2081 can insert dynamically at runtime instead of at compiletime.
2083 ** "set print symbol"
2085 Controls whether GDB attempts to display the symbol, if any,
2086 corresponding to addresses it prints. This defaults to "on", but
2087 you can set it to "off" to restore GDB's previous behavior.
2089 * Deprecated commands
2091 ** For the Renesas Super-H architecture, the "regs" command has been
2092 deprecated, and "info all-registers" should be used instead.
2096 Renesas RL78 rl78-*-elf
2097 HP OpenVMS ia64 ia64-hp-openvms*
2099 * GDBserver supports evaluation of breakpoint conditions. When
2100 support is advertised by GDBserver, GDB may be told to send the
2101 breakpoint conditions in bytecode form to GDBserver. GDBserver
2102 will only report the breakpoint trigger to GDB when its condition
2107 set mips compression
2108 show mips compression
2109 Select the compressed ISA encoding used in functions that have no symbol
2110 information available. The encoding can be set to either of:
2113 and is updated automatically from ELF file flags if available.
2115 set breakpoint condition-evaluation
2116 show breakpoint condition-evaluation
2117 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2118 GDBserver ("target"). Default option "auto" chooses the most efficient
2120 This option can improve debugger efficiency depending on the speed of the
2124 Disable auto-loading globally.
2127 Show auto-loading setting of all kinds of auto-loaded files.
2129 set auto-load gdb-scripts on|off
2130 show auto-load gdb-scripts
2131 Control auto-loading of GDB canned sequences of commands files.
2133 set auto-load python-scripts on|off
2134 show auto-load python-scripts
2135 Control auto-loading of Python script files.
2137 set auto-load local-gdbinit on|off
2138 show auto-load local-gdbinit
2139 Control loading of init file (.gdbinit) from current directory.
2141 set auto-load libthread-db on|off
2142 show auto-load libthread-db
2143 Control auto-loading of inferior specific thread debugging shared library.
2145 set auto-load scripts-directory <dir1>[:<dir2>...]
2146 show auto-load scripts-directory
2147 Set a list of directories from which to load auto-loaded scripts.
2148 Automatically loaded Python scripts and GDB scripts are located in one
2149 of the directories listed by this option.
2150 The delimiter (':' above) may differ according to the host platform.
2152 set auto-load safe-path <dir1>[:<dir2>...]
2153 show auto-load safe-path
2154 Set a list of directories from which it is safe to auto-load files.
2155 The delimiter (':' above) may differ according to the host platform.
2157 set debug auto-load on|off
2158 show debug auto-load
2159 Control display of debugging info for auto-loading the files above.
2161 set dprintf-style gdb|call|agent
2163 Control the way in which a dynamic printf is performed; "gdb"
2164 requests a GDB printf command, while "call" causes dprintf to call a
2165 function in the inferior. "agent" requests that the target agent
2166 (such as GDBserver) do the printing.
2168 set dprintf-function <expr>
2169 show dprintf-function
2170 set dprintf-channel <expr>
2171 show dprintf-channel
2172 Set the function and optional first argument to the call when using
2173 the "call" style of dynamic printf.
2175 set disconnected-dprintf on|off
2176 show disconnected-dprintf
2177 Control whether agent-style dynamic printfs continue to be in effect
2178 after GDB disconnects.
2180 * New configure options
2182 --with-auto-load-dir
2183 Configure default value for the 'set auto-load scripts-directory'
2184 setting above. It defaults to '$debugdir:$datadir/auto-load',
2185 $debugdir representing global debugging info directories (available
2186 via 'show debug-file-directory') and $datadir representing GDB's data
2187 directory (available via 'show data-directory').
2189 --with-auto-load-safe-path
2190 Configure default value for the 'set auto-load safe-path' setting
2191 above. It defaults to the --with-auto-load-dir setting.
2193 --without-auto-load-safe-path
2194 Set 'set auto-load safe-path' to '/', effectively disabling this
2197 * New remote packets
2199 z0/z1 conditional breakpoints extension
2201 The z0/z1 breakpoint insertion packets have been extended to carry
2202 a list of conditional expressions over to the remote stub depending on the
2203 condition evaluation mode. The use of this extension can be controlled
2204 via the "set remote conditional-breakpoints-packet" command.
2208 Specify the signals which the remote stub may pass to the debugged
2209 program without GDB involvement.
2211 * New command line options
2213 --init-command=FILE, -ix Like --command, -x but execute it
2214 before loading inferior.
2215 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2216 execute it before loading inferior.
2218 *** Changes in GDB 7.4
2220 * GDB now handles ambiguous linespecs more consistently; the existing
2221 FILE:LINE support has been expanded to other types of linespecs. A
2222 breakpoint will now be set on all matching locations in all
2223 inferiors, and locations will be added or removed according to
2226 * GDB now allows you to skip uninteresting functions and files when
2227 stepping with the "skip function" and "skip file" commands.
2229 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2230 and "show remote hardware-watchpoint-length-limit". These allows to
2231 set or show the maximum length limit (in bytes) of a remote
2232 target hardware watchpoint.
2234 This allows e.g. to use "unlimited" hardware watchpoints with the
2235 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2236 watchpoints are slower than real hardware watchpoints but are
2237 significantly faster than gdb software watchpoints.
2241 ** The register_pretty_printer function in module gdb.printing now takes
2242 an optional `replace' argument. If True, the new printer replaces any
2245 ** The "maint set python print-stack on|off" command has been
2246 deprecated and will be deleted in GDB 7.5.
2247 A new command: "set python print-stack none|full|message" has
2248 replaced it. Additionally, the default for "print-stack" is
2249 now "message", which just prints the error message without
2252 ** A prompt substitution hook (prompt_hook) is now available to the
2255 ** A new Python module, gdb.prompt has been added to the GDB Python
2256 modules library. This module provides functionality for
2257 escape sequences in prompts (used by set/show
2258 extended-prompt). These escape sequences are replaced by their
2259 corresponding value.
2261 ** Python commands and convenience-functions located in
2262 'data-directory'/python/gdb/command and
2263 'data-directory'/python/gdb/function are now automatically loaded
2266 ** Blocks now provide four new attributes. global_block and
2267 static_block will return the global and static blocks
2268 respectively. is_static and is_global are boolean attributes
2269 that indicate if the block is one of those two types.
2271 ** Symbols now provide the "type" attribute, the type of the symbol.
2273 ** The "gdb.breakpoint" function has been deprecated in favor of
2276 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2277 of a function. This class is based on the "finish" command
2278 available in the CLI.
2280 ** Type objects for struct and union types now allow access to
2281 the fields using standard Python dictionary (mapping) methods.
2282 For example, "some_type['myfield']" now works, as does
2283 "some_type.items()".
2285 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2288 ** A new function, "deep_items" has been added to the gdb.types
2289 module in the GDB Python modules library. This function returns
2290 an iterator over the fields of a struct or union type. Unlike
2291 the standard Python "iteritems" method, it will recursively traverse
2292 any anonymous fields.
2296 ** "*stopped" events can report several new "reason"s, such as
2299 ** Breakpoint changes are now notified using new async records, like
2300 "=breakpoint-modified".
2302 ** New command -ada-task-info.
2304 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2305 $sdir specifies the default system locations of shared libraries.
2306 $pdir specifies the directory where the libpthread used by the application
2309 GDB no longer looks in $sdir and $pdir after it has searched the directories
2310 mentioned in libthread-db-search-path. If you want to search those
2311 directories, they must be specified in libthread-db-search-path.
2312 The default value of libthread-db-search-path on GNU/Linux and Solaris
2313 systems is now "$sdir:$pdir".
2315 $pdir is not supported by gdbserver, it is currently ignored.
2316 $sdir is supported by gdbserver.
2318 * New configure option --with-iconv-bin.
2319 When using the internationalization support like the one in the GNU C
2320 library, GDB will invoke the "iconv" program to get a list of supported
2321 character sets. If this program lives in a non-standard location, one can
2322 use this option to specify where to find it.
2324 * When natively debugging programs on PowerPC BookE processors running
2325 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2326 watchpoints, which specify a mask in addition to an address to watch.
2327 The mask specifies that some bits of an address (the bits which are
2328 reset in the mask) should be ignored when matching the address accessed
2329 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2330 section in the user manual for more details.
2332 * The new option --once causes GDBserver to stop listening for connections once
2333 the first connection is made. The listening port used by GDBserver will
2334 become available after that.
2336 * New commands "info macros" and "alias" have been added.
2338 * New function parameters suffix @entry specifies value of function parameter
2339 at the time the function got called. Entry values are available only since
2345 "!" is now an alias of the "shell" command.
2346 Note that no space is needed between "!" and SHELL COMMAND.
2350 watch EXPRESSION mask MASK_VALUE
2351 The watch command now supports the mask argument which allows creation
2352 of masked watchpoints, if the current architecture supports this feature.
2354 info auto-load-scripts [REGEXP]
2355 This command was formerly named "maintenance print section-scripts".
2356 It is now generally useful and is no longer a maintenance-only command.
2358 info macro [-all] [--] MACRO
2359 The info macro command has new options `-all' and `--'. The first for
2360 printing all definitions of a macro. The second for explicitly specifying
2361 the end of arguments and the beginning of the macro name in case the macro
2362 name starts with a hyphen.
2364 collect[/s] EXPRESSIONS
2365 The tracepoint collect command now takes an optional modifier "/s"
2366 that directs it to dereference pointer-to-character types and
2367 collect the bytes of memory up to a zero byte. The behavior is
2368 similar to what you see when you use the regular print command on a
2369 string. An optional integer following the "/s" sets a bound on the
2370 number of bytes that will be collected.
2373 The trace start command now interprets any supplied arguments as a
2374 note to be recorded with the trace run, with an effect similar to
2375 setting the variable trace-notes.
2378 The trace stop command now interprets any arguments as a note to be
2379 mentioned along with the tstatus report that the trace was stopped
2380 with a command. The effect is similar to setting the variable
2383 * Tracepoints can now be enabled and disabled at any time after a trace
2384 experiment has been started using the standard "enable" and "disable"
2385 commands. It is now possible to start a trace experiment with no enabled
2386 tracepoints; GDB will display a warning, but will allow the experiment to
2387 begin, assuming that tracepoints will be enabled as needed while the trace
2390 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2391 locations with 4-byte instructions, when they were previously
2392 limited to locations with instructions of 5 bytes or longer.
2396 set debug dwarf2-read
2397 show debug dwarf2-read
2398 Turns on or off display of debugging messages related to reading
2399 DWARF debug info. The default is off.
2401 set debug symtab-create
2402 show debug symtab-create
2403 Turns on or off display of debugging messages related to symbol table
2404 creation. The default is off.
2407 show extended-prompt
2408 Set the GDB prompt, and allow escape sequences to be inserted to
2409 display miscellaneous information (see 'help set extended-prompt'
2410 for the list of sequences). This prompt (and any information
2411 accessed through the escape sequences) is updated every time the
2412 prompt is displayed.
2414 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2415 show print entry-values
2416 Set printing of frame argument values at function entry. In some cases
2417 GDB can determine the value of function argument which was passed by the
2418 function caller, even if the value was modified inside the called function.
2420 set debug entry-values
2421 show debug entry-values
2422 Control display of debugging info for determining frame argument values at
2423 function entry and virtual tail call frames.
2425 set basenames-may-differ
2426 show basenames-may-differ
2427 Set whether a source file may have multiple base names.
2428 (A "base name" is the name of a file with the directory part removed.
2429 Example: The base name of "/home/user/hello.c" is "hello.c".)
2430 If set, GDB will canonicalize file names (e.g., expand symlinks)
2431 before comparing them. Canonicalization is an expensive operation,
2432 but it allows the same file be known by more than one base name.
2433 If not set (the default), all source files are assumed to have just
2434 one base name, and gdb will do file name comparisons more efficiently.
2440 Set a user name and notes for the current and any future trace runs.
2441 This is useful for long-running and/or disconnected traces, to
2442 inform others (or yourself) as to who is running the trace, supply
2443 contact information, or otherwise explain what is going on.
2445 set trace-stop-notes
2446 show trace-stop-notes
2447 Set a note attached to the trace run, that is displayed when the
2448 trace has been stopped by a tstop command. This is useful for
2449 instance as an explanation, if you are stopping a trace run that was
2450 started by someone else.
2452 * New remote packets
2456 Dynamically enable a tracepoint in a started trace experiment.
2460 Dynamically disable a tracepoint in a started trace experiment.
2464 Set the user and notes of the trace run.
2468 Query the current status of a tracepoint.
2472 Query the minimum length of instruction at which a fast tracepoint may
2475 * Dcache size (number of lines) and line-size are now runtime-configurable
2476 via "set dcache line" and "set dcache line-size" commands.
2480 Texas Instruments TMS320C6x tic6x-*-*
2484 Renesas RL78 rl78-*-elf
2486 *** Changes in GDB 7.3.1
2488 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2490 *** Changes in GDB 7.3
2492 * GDB has a new command: "thread find [REGEXP]".
2493 It finds the thread id whose name, target id, or thread extra info
2494 matches the given regular expression.
2496 * The "catch syscall" command now works on mips*-linux* targets.
2498 * The -data-disassemble MI command now supports modes 2 and 3 for
2499 dumping the instruction opcodes.
2501 * New command line options
2503 -data-directory DIR Specify DIR as the "data-directory".
2504 This is mostly for testing purposes.
2506 * The "maint set python auto-load on|off" command has been renamed to
2507 "set auto-load-scripts on|off".
2509 * GDB has a new command: "set directories".
2510 It is like the "dir" command except that it replaces the
2511 source path list instead of augmenting it.
2513 * GDB now understands thread names.
2515 On GNU/Linux, "info threads" will display the thread name as set by
2516 prctl or pthread_setname_np.
2518 There is also a new command, "thread name", which can be used to
2519 assign a name internally for GDB to display.
2522 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2523 has been integrated into GDB.
2527 ** The function gdb.Write now accepts an optional keyword 'stream'.
2528 This keyword, when provided, will direct the output to either
2529 stdout, stderr, or GDB's logging output.
2531 ** Parameters can now be be sub-classed in Python, and in particular
2532 you may implement the get_set_doc and get_show_doc functions.
2533 This improves how Parameter set/show documentation is processed
2534 and allows for more dynamic content.
2536 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2537 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2538 have an is_valid method.
2540 ** Breakpoints can now be sub-classed in Python, and in particular
2541 you may implement a 'stop' function that is executed each time
2542 the inferior reaches that breakpoint.
2544 ** New function gdb.lookup_global_symbol looks up a global symbol.
2546 ** GDB values in Python are now callable if the value represents a
2547 function. For example, if 'some_value' represents a function that
2548 takes two integer parameters and returns a value, you can call
2549 that function like so:
2551 result = some_value (10,20)
2553 ** Module gdb.types has been added.
2554 It contains a collection of utilities for working with gdb.Types objects:
2555 get_basic_type, has_field, make_enum_dict.
2557 ** Module gdb.printing has been added.
2558 It contains utilities for writing and registering pretty-printers.
2559 New classes: PrettyPrinter, SubPrettyPrinter,
2560 RegexpCollectionPrettyPrinter.
2561 New function: register_pretty_printer.
2563 ** New commands "info pretty-printers", "enable pretty-printer" and
2564 "disable pretty-printer" have been added.
2566 ** gdb.parameter("directories") is now available.
2568 ** New function gdb.newest_frame returns the newest frame in the
2571 ** The gdb.InferiorThread class has a new "name" attribute. This
2572 holds the thread's name.
2574 ** Python Support for Inferior events.
2575 Python scripts can add observers to be notified of events
2576 occurring in the process being debugged.
2577 The following events are currently supported:
2578 - gdb.events.cont Continue event.
2579 - gdb.events.exited Inferior exited event.
2580 - gdb.events.stop Signal received, and Breakpoint hit events.
2584 ** GDB now puts template parameters in scope when debugging in an
2585 instantiation. For example, if you have:
2587 template<int X> int func (void) { return X; }
2589 then if you step into func<5>, "print X" will show "5". This
2590 feature requires proper debuginfo support from the compiler; it
2591 was added to GCC 4.5.
2593 ** The motion commands "next", "finish", "until", and "advance" now
2594 work better when exceptions are thrown. In particular, GDB will
2595 no longer lose control of the inferior; instead, the GDB will
2596 stop the inferior at the point at which the exception is caught.
2597 This functionality requires a change in the exception handling
2598 code that was introduced in GCC 4.5.
2600 * GDB now follows GCC's rules on accessing volatile objects when
2601 reading or writing target state during expression evaluation.
2602 One notable difference to prior behavior is that "print x = 0"
2603 no longer generates a read of x; the value of the assignment is
2604 now always taken directly from the value being assigned.
2606 * GDB now has some support for using labels in the program's source in
2607 linespecs. For instance, you can use "advance label" to continue
2608 execution to a label.
2610 * GDB now has support for reading and writing a new .gdb_index
2611 section. This section holds a fast index of DWARF debugging
2612 information and can be used to greatly speed up GDB startup and
2613 operation. See the documentation for `save gdb-index' for details.
2615 * The "watch" command now accepts an optional "-location" argument.
2616 When used, this causes GDB to watch the memory referred to by the
2617 expression. Such a watchpoint is never deleted due to it going out
2620 * GDB now supports thread debugging of core dumps on GNU/Linux.
2622 GDB now activates thread debugging using the libthread_db library
2623 when debugging GNU/Linux core dumps, similarly to when debugging
2624 live processes. As a result, when debugging a core dump file, GDB
2625 is now able to display pthread_t ids of threads. For example, "info
2626 threads" shows the same output as when debugging the process when it
2627 was live. In earlier releases, you'd see something like this:
2630 * 1 LWP 6780 main () at main.c:10
2632 While now you see this:
2635 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2637 It is also now possible to inspect TLS variables when debugging core
2640 When debugging a core dump generated on a machine other than the one
2641 used to run GDB, you may need to point GDB at the correct
2642 libthread_db library with the "set libthread-db-search-path"
2643 command. See the user manual for more details on this command.
2645 * When natively debugging programs on PowerPC BookE processors running
2646 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2647 which stop execution of the inferior whenever it executes an instruction
2648 at any address within the specified range. See the "PowerPC Embedded"
2649 section in the user manual for more details.
2651 * New features in the GDB remote stub, GDBserver
2653 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2654 and i686 LynxOS (version 5.x).
2656 ** GDBserver is now supported on Blackfin Linux.
2658 * New native configurations
2660 ia64 HP-UX ia64-*-hpux*
2664 Analog Devices, Inc. Blackfin Processor bfin-*
2666 * Ada task switching is now supported on sparc-elf targets when
2667 debugging a program using the Ravenscar Profile. For more information,
2668 see the "Tasking Support when using the Ravenscar Profile" section
2669 in the GDB user manual.
2671 * Guile support was removed.
2673 * New features in the GNU simulator
2675 ** The --map-info flag lists all known core mappings.
2677 ** CFI flashes may be simulated via the "cfi" device.
2679 *** Changes in GDB 7.2
2681 * Shared library support for remote targets by default
2683 When GDB is configured for a generic, non-OS specific target, like
2684 for example, --target=arm-eabi or one of the many *-*-elf targets,
2685 GDB now queries remote stubs for loaded shared libraries using the
2686 `qXfer:libraries:read' packet. Previously, shared library support
2687 was always disabled for such configurations.
2691 ** Argument Dependent Lookup (ADL)
2693 In C++ ADL lookup directs function search to the namespaces of its
2694 arguments even if the namespace has not been imported.
2704 Here the compiler will search for `foo' in the namespace of 'b'
2705 and find A::foo. GDB now supports this. This construct is commonly
2706 used in the Standard Template Library for operators.
2708 ** Improved User Defined Operator Support
2710 In addition to member operators, GDB now supports lookup of operators
2711 defined in a namespace and imported with a `using' directive, operators
2712 defined in the global scope, operators imported implicitly from an
2713 anonymous namespace, and the ADL operators mentioned in the previous
2715 GDB now also supports proper overload resolution for all the previously
2716 mentioned flavors of operators.
2718 ** static const class members
2720 Printing of static const class members that are initialized in the
2721 class definition has been fixed.
2723 * Windows Thread Information Block access.
2725 On Windows targets, GDB now supports displaying the Windows Thread
2726 Information Block (TIB) structure. This structure is visible either
2727 by using the new command `info w32 thread-information-block' or, by
2728 dereferencing the new convenience variable named `$_tlb', a
2729 thread-specific pointer to the TIB. This feature is also supported
2730 when remote debugging using GDBserver.
2732 * Static tracepoints
2734 Static tracepoints are calls in the user program into a tracing
2735 library. One such library is a port of the LTTng kernel tracer to
2736 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2737 When debugging with GDBserver, GDB now supports combining the GDB
2738 tracepoint machinery with such libraries. For example: the user can
2739 use GDB to probe a static tracepoint marker (a call from the user
2740 program into the tracing library) with the new "strace" command (see
2741 "New commands" below). This creates a "static tracepoint" in the
2742 breakpoint list, that can be manipulated with the same feature set
2743 as fast and regular tracepoints. E.g., collect registers, local and
2744 global variables, collect trace state variables, and define
2745 tracepoint conditions. In addition, the user can collect extra
2746 static tracepoint marker specific data, by collecting the new
2747 $_sdata internal variable. When analyzing the trace buffer, you can
2748 inspect $_sdata like any other variable available to GDB. For more
2749 information, see the "Tracepoints" chapter in GDB user manual. New
2750 remote packets have been defined to support static tracepoints, see
2751 the "New remote packets" section below.
2753 * Better reconstruction of tracepoints after disconnected tracing
2755 GDB will attempt to download the original source form of tracepoint
2756 definitions when starting a trace run, and then will upload these
2757 upon reconnection to the target, resulting in a more accurate
2758 reconstruction of the tracepoints that are in use on the target.
2762 You can now exercise direct control over the ways that GDB can
2763 affect your program. For instance, you can disallow the setting of
2764 breakpoints, so that the program can run continuously (assuming
2765 non-stop mode). In addition, the "observer" variable is available
2766 to switch all of the different controls; in observer mode, GDB
2767 cannot affect the target's behavior at all, which is useful for
2768 tasks like diagnosing live systems in the field.
2770 * The new convenience variable $_thread holds the number of the
2773 * New remote packets
2777 Return the address of the Windows Thread Information Block of a given thread.
2781 In response to several of the tracepoint packets, the target may now
2782 also respond with a number of intermediate `qRelocInsn' request
2783 packets before the final result packet, to have GDB handle
2784 relocating an instruction to execute at a different address. This
2785 is particularly useful for stubs that support fast tracepoints. GDB
2786 reports support for this feature in the qSupported packet.
2790 List static tracepoint markers in the target program.
2794 List static tracepoint markers at a given address in the target
2797 qXfer:statictrace:read
2799 Read the static trace data collected (by a `collect $_sdata'
2800 tracepoint action). The remote stub reports support for this packet
2801 to gdb's qSupported query.
2805 Send the current settings of GDB's permission flags.
2809 Send part of the source (textual) form of a tracepoint definition,
2810 which includes location, conditional, and action list.
2812 * The source command now accepts a -s option to force searching for the
2813 script in the source search path even if the script name specifies
2816 * New features in the GDB remote stub, GDBserver
2818 - GDBserver now support tracepoints (including fast tracepoints, and
2819 static tracepoints). The feature is currently supported by the
2820 i386-linux and amd64-linux builds. See the "Tracepoints support
2821 in gdbserver" section in the manual for more information.
2823 GDBserver JIT compiles the tracepoint's conditional agent
2824 expression bytecode into native code whenever possible for low
2825 overhead dynamic tracepoints conditionals. For such tracepoints,
2826 an expression that examines program state is evaluated when the
2827 tracepoint is reached, in order to determine whether to capture
2828 trace data. If the condition is simple and false, processing the
2829 tracepoint finishes very quickly and no data is gathered.
2831 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2832 for static tracepoints support.
2834 - GDBserver now supports x86_64 Windows 64-bit debugging.
2836 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2837 it understands register description.
2839 * The --batch flag now disables pagination and queries.
2841 * X86 general purpose registers
2843 GDB now supports reading/writing byte, word and double-word x86
2844 general purpose registers directly. This means you can use, say,
2845 $ah or $ax to refer, respectively, to the byte register AH and
2846 16-bit word register AX that are actually portions of the 32-bit
2847 register EAX or 64-bit register RAX.
2849 * The `commands' command now accepts a range of breakpoints to modify.
2850 A plain `commands' following a command that creates multiple
2851 breakpoints affects all the breakpoints set by that command. This
2852 applies to breakpoints set by `rbreak', and also applies when a
2853 single `break' command creates multiple breakpoints (e.g.,
2854 breakpoints on overloaded c++ functions).
2856 * The `rbreak' command now accepts a filename specification as part of
2857 its argument, limiting the functions selected by the regex to those
2858 in the specified file.
2860 * Support for remote debugging Windows and SymbianOS shared libraries
2861 from Unix hosts has been improved. Non Windows GDB builds now can
2862 understand target reported file names that follow MS-DOS based file
2863 system semantics, such as file names that include drive letters and
2864 use the backslash character as directory separator. This makes it
2865 possible to transparently use the "set sysroot" and "set
2866 solib-search-path" on Unix hosts to point as host copies of the
2867 target's shared libraries. See the new command "set
2868 target-file-system-kind" described below, and the "Commands to
2869 specify files" section in the user manual for more information.
2873 eval template, expressions...
2874 Convert the values of one or more expressions under the control
2875 of the string template to a command line, and call it.
2877 set target-file-system-kind unix|dos-based|auto
2878 show target-file-system-kind
2879 Set or show the assumed file system kind for target reported file
2882 save breakpoints <filename>
2883 Save all current breakpoint definitions to a file suitable for use
2884 in a later debugging session. To read the saved breakpoint
2885 definitions, use the `source' command.
2887 `save tracepoints' is a new alias for `save-tracepoints'. The latter
2890 info static-tracepoint-markers
2891 Display information about static tracepoint markers in the target.
2893 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
2894 Define a static tracepoint by probing a marker at the given
2895 function, line, address, or marker ID.
2899 Enable and disable observer mode.
2901 set may-write-registers on|off
2902 set may-write-memory on|off
2903 set may-insert-breakpoints on|off
2904 set may-insert-tracepoints on|off
2905 set may-insert-fast-tracepoints on|off
2906 set may-interrupt on|off
2907 Set individual permissions for GDB effects on the target. Note that
2908 some of these settings can have undesirable or surprising
2909 consequences, particularly when changed in the middle of a session.
2910 For instance, disabling the writing of memory can prevent
2911 breakpoints from being inserted, cause single-stepping to fail, or
2912 even crash your program, if you disable after breakpoints have been
2913 inserted. However, GDB should not crash.
2915 set record memory-query on|off
2916 show record memory-query
2917 Control whether to stop the inferior if memory changes caused
2918 by an instruction cannot be recorded.
2923 The disassemble command now supports "start,+length" form of two arguments.
2927 ** GDB now provides a new directory location, called the python directory,
2928 where Python scripts written for GDB can be installed. The location
2929 of that directory is <data-directory>/python, where <data-directory>
2930 is the GDB data directory. For more details, see section `Scripting
2931 GDB using Python' in the manual.
2933 ** The GDB Python API now has access to breakpoints, symbols, symbol
2934 tables, program spaces, inferiors, threads and frame's code blocks.
2935 Additionally, GDB Parameters can now be created from the API, and
2936 manipulated via set/show in the CLI.
2938 ** New functions gdb.target_charset, gdb.target_wide_charset,
2939 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
2941 ** New exception gdb.GdbError.
2943 ** Pretty-printers are now also looked up in the current program space.
2945 ** Pretty-printers can now be individually enabled and disabled.
2947 ** GDB now looks for names of Python scripts to auto-load in a
2948 special section named `.debug_gdb_scripts', in addition to looking
2949 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
2951 * Tracepoint actions were unified with breakpoint commands. In particular,
2952 there are no longer differences in "info break" output for breakpoints and
2953 tracepoints and the "commands" command can be used for both tracepoints and
2954 regular breakpoints.
2958 ARM Symbian arm*-*-symbianelf*
2960 * D language support.
2961 GDB now supports debugging programs written in the D programming
2964 * GDB now supports the extended ptrace interface for PowerPC which is
2965 available since Linux kernel version 2.6.34. This automatically enables
2966 any hardware breakpoints and additional hardware watchpoints available in
2967 the processor. The old ptrace interface exposes just one hardware
2968 watchpoint and no hardware breakpoints.
2970 * GDB is now able to use the Data Value Compare (DVC) register available on
2971 embedded PowerPC processors to implement in hardware simple watchpoint
2972 conditions of the form:
2974 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
2976 This works in native GDB running on Linux kernels with the extended ptrace
2977 interface mentioned above.
2979 *** Changes in GDB 7.1
2983 ** Namespace Support
2985 GDB now supports importing of namespaces in C++. This enables the
2986 user to inspect variables from imported namespaces. Support for
2987 namepace aliasing has also been added. So, if a namespace is
2988 aliased in the current scope (e.g. namepace C=A; ) the user can
2989 print variables using the alias (e.g. (gdb) print C::x).
2993 All known bugs relating to the printing of virtual base class were
2994 fixed. It is now possible to call overloaded static methods using a
2999 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3000 and reinterpret_cast<> are now handled by the C++ expression parser.
3004 Xilinx MicroBlaze microblaze-*-*
3009 Xilinx MicroBlaze microblaze
3012 * Multi-program debugging.
3014 GDB now has support for multi-program (a.k.a. multi-executable or
3015 multi-exec) debugging. This allows for debugging multiple inferiors
3016 simultaneously each running a different program under the same GDB
3017 session. See "Debugging Multiple Inferiors and Programs" in the
3018 manual for more information. This implied some user visible changes
3019 in the multi-inferior support. For example, "info inferiors" now
3020 lists inferiors that are not running yet or that have exited
3021 already. See also "New commands" and "New options" below.
3023 * New tracing features
3025 GDB's tracepoint facility now includes several new features:
3027 ** Trace state variables
3029 GDB tracepoints now include support for trace state variables, which
3030 are variables managed by the target agent during a tracing
3031 experiment. They are useful for tracepoints that trigger each
3032 other, so for instance one tracepoint can count hits in a variable,
3033 and then a second tracepoint has a condition that is true when the
3034 count reaches a particular value. Trace state variables share the
3035 $-syntax of GDB convenience variables, and can appear in both
3036 tracepoint actions and condition expressions. Use the "tvariable"
3037 command to create, and "info tvariables" to view; see "Trace State
3038 Variables" in the manual for more detail.
3042 GDB now includes an option for defining fast tracepoints, which
3043 targets may implement more efficiently, such as by installing a jump
3044 into the target agent rather than a trap instruction. The resulting
3045 speedup can be by two orders of magnitude or more, although the
3046 tradeoff is that some program locations on some target architectures
3047 might not allow fast tracepoint installation, for instance if the
3048 instruction to be replaced is shorter than the jump. To request a
3049 fast tracepoint, use the "ftrace" command, with syntax identical to
3050 the regular trace command.
3052 ** Disconnected tracing
3054 It is now possible to detach GDB from the target while it is running
3055 a trace experiment, then reconnect later to see how the experiment
3056 is going. In addition, a new variable disconnected-tracing lets you
3057 tell the target agent whether to continue running a trace if the
3058 connection is lost unexpectedly.
3062 GDB now has the ability to save the trace buffer into a file, and
3063 then use that file as a target, similarly to you can do with
3064 corefiles. You can select trace frames, print data that was
3065 collected in them, and use tstatus to display the state of the
3066 tracing run at the moment that it was saved. To create a trace
3067 file, use "tsave <filename>", and to use it, do "target tfile
3070 ** Circular trace buffer
3072 You can ask the target agent to handle the trace buffer as a
3073 circular buffer, discarding the oldest trace frames to make room for
3074 newer ones, by setting circular-trace-buffer to on. This feature may
3075 not be available for all target agents.
3080 The disassemble command, when invoked with two arguments, now requires
3081 the arguments to be comma-separated.
3084 The info variables command now displays variable definitions. Files
3085 which only declare a variable are not shown.
3088 The source command is now capable of sourcing Python scripts.
3089 This feature is dependent on the debugger being build with Python
3092 Related to this enhancement is also the introduction of a new command
3093 "set script-extension" (see below).
3095 * New commands (for set/show, see "New options" below)
3097 record save [<FILENAME>]
3098 Save a file (in core file format) containing the process record
3099 execution log for replay debugging at a later time.
3101 record restore <FILENAME>
3102 Restore the process record execution log that was saved at an
3103 earlier time, for replay debugging.
3105 add-inferior [-copies <N>] [-exec <FILENAME>]
3108 clone-inferior [-copies <N>] [ID]
3109 Make a new inferior ready to execute the same program another
3110 inferior has loaded.
3115 maint info program-spaces
3116 List the program spaces loaded into GDB.
3118 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3119 show remote interrupt-sequence
3120 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3121 as the sequence to the remote target in order to interrupt the execution.
3122 Ctrl-C is a default. Some system prefers BREAK which is high level of
3123 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3124 Magic SysRq g. It is BREAK signal and character 'g'.
3126 set remote interrupt-on-connect [on | off]
3127 show remote interrupt-on-connect
3128 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3129 remote target when gdb connects to it. This is needed when you debug
3132 set remotebreak [on | off]
3134 Deprecated. Use "set/show remote interrupt-sequence" instead.
3136 tvariable $NAME [ = EXP ]
3137 Create or modify a trace state variable.
3140 List trace state variables and their values.
3142 delete tvariable $NAME ...
3143 Delete one or more trace state variables.
3146 Evaluate the given expressions without collecting anything into the
3147 trace buffer. (Valid in tracepoint actions only.)
3149 ftrace FN / FILE:LINE / *ADDR
3150 Define a fast tracepoint at the given function, line, or address.
3152 * New expression syntax
3154 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3155 GDB now parses 0b101010 identically with 42.
3159 set follow-exec-mode new|same
3160 show follow-exec-mode
3161 Control whether GDB reuses the same inferior across an exec call or
3162 creates a new one. This is useful to be able to restart the old
3163 executable after the inferior having done an exec call.
3165 set default-collect EXPR, ...
3166 show default-collect
3167 Define a list of expressions to be collected at each tracepoint.
3168 This is a useful way to ensure essential items are not overlooked,
3169 such as registers or a critical global variable.
3171 set disconnected-tracing
3172 show disconnected-tracing
3173 If set to 1, the target is instructed to continue tracing if it
3174 loses its connection to GDB. If 0, the target is to stop tracing
3177 set circular-trace-buffer
3178 show circular-trace-buffer
3179 If set to on, the target is instructed to use a circular trace buffer
3180 and discard the oldest trace frames instead of stopping the trace due
3181 to a full trace buffer. If set to off, the trace stops when the buffer
3182 fills up. Some targets may not support this.
3184 set script-extension off|soft|strict
3185 show script-extension
3186 If set to "off", the debugger does not perform any script language
3187 recognition, and all sourced files are assumed to be GDB scripts.
3188 If set to "soft" (the default), files are sourced according to
3189 filename extension, falling back to GDB scripts if the first
3191 If set to "strict", files are sourced according to filename extension.
3193 set ada trust-PAD-over-XVS on|off
3194 show ada trust-PAD-over-XVS
3195 If off, activate a workaround against a bug in the debugging information
3196 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3197 the GCC sources for more information about the GNAT encoding and
3198 PAD types in particular). It is always safe to set this option to
3199 off, but this introduces a slight performance penalty. The default
3202 * Python API Improvements
3204 ** GDB provides the new class gdb.LazyString. This is useful in
3205 some pretty-printing cases. The new method gdb.Value.lazy_string
3206 provides a simple way to create objects of this type.
3208 ** The fields returned by gdb.Type.fields now have an
3209 `is_base_class' attribute.
3211 ** The new method gdb.Type.range returns the range of an array type.
3213 ** The new method gdb.parse_and_eval can be used to parse and
3214 evaluate an expression.
3216 * New remote packets
3219 Define a trace state variable.
3222 Get the current value of a trace state variable.
3225 Set desired tracing behavior upon disconnection.
3228 Set the trace buffer to be linear or circular.
3231 Get data about the tracepoints currently in use.
3235 Process record now works correctly with hardware watchpoints.
3237 Multiple bug fixes have been made to the mips-irix port, making it
3238 much more reliable. In particular:
3239 - Debugging threaded applications is now possible again. Previously,
3240 GDB would hang while starting the program, or while waiting for
3241 the program to stop at a breakpoint.
3242 - Attaching to a running process no longer hangs.
3243 - An error occurring while loading a core file has been fixed.
3244 - Changing the value of the PC register now works again. This fixes
3245 problems observed when using the "jump" command, or when calling
3246 a function from GDB, or even when assigning a new value to $pc.
3247 - With the "finish" and "return" commands, the return value for functions
3248 returning a small array is now correctly printed.
3249 - It is now possible to break on shared library code which gets executed
3250 during a shared library init phase (code executed while executing
3251 their .init section). Previously, the breakpoint would have no effect.
3252 - GDB is now able to backtrace through the signal handler for
3253 non-threaded programs.
3255 PIE (Position Independent Executable) programs debugging is now supported.
3256 This includes debugging execution of PIC (Position Independent Code) shared
3257 libraries although for that, it should be possible to run such libraries as an
3260 *** Changes in GDB 7.0
3262 * GDB now has an interface for JIT compilation. Applications that
3263 dynamically generate code can create symbol files in memory and register
3264 them with GDB. For users, the feature should work transparently, and
3265 for JIT developers, the interface is documented in the GDB manual in the
3266 "JIT Compilation Interface" chapter.
3268 * Tracepoints may now be conditional. The syntax is as for
3269 breakpoints; either an "if" clause appended to the "trace" command,
3270 or the "condition" command is available. GDB sends the condition to
3271 the target for evaluation using the same bytecode format as is used
3272 for tracepoint actions.
3274 * The disassemble command now supports: an optional /r modifier, print the
3275 raw instructions in hex as well as in symbolic form, and an optional /m
3276 modifier to print mixed source+assembly.
3278 * Process record and replay
3280 In a architecture environment that supports ``process record and
3281 replay'', ``process record and replay'' target can record a log of
3282 the process execution, and replay it with both forward and reverse
3285 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3286 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3287 set execution-direction {forward|reverse}, for targets that support
3290 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3291 feature is available with a native GDB running on kernel version
3294 * GDB now has support for multi-byte and wide character sets on the
3295 target. Strings whose character type is wchar_t, char16_t, or
3296 char32_t are now correctly printed. GDB supports wide- and unicode-
3297 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3298 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3299 `printf'. This feature requires iconv to work properly; if your
3300 system does not have a working iconv, GDB can use GNU libiconv. See
3301 the installation instructions for more information.
3303 * GDB now supports automatic retrieval of shared library files from
3304 remote targets. To use this feature, specify a system root that begins
3305 with the `remote:' prefix, either via the `set sysroot' command or via
3306 the `--with-sysroot' configure-time option.
3308 * "info sharedlibrary" now takes an optional regex of libraries to show,
3309 and it now reports if a shared library has no debugging information.
3311 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3312 now complete on file names.
3314 * When completing in expressions, gdb will attempt to limit
3315 completions to allowable structure or union fields, where appropriate.
3316 For instance, consider:
3318 # struct example { int f1; double f2; };
3319 # struct example variable;
3322 If the user types TAB at the end of this command line, the available
3323 completions will be "f1" and "f2".
3325 * Inlined functions are now supported. They show up in backtraces, and
3326 the "step", "next", and "finish" commands handle them automatically.
3328 * GDB now supports the token-splicing (##) and stringification (#)
3329 operators when expanding macros. It also supports variable-arity
3332 * GDB now supports inspecting extra signal information, exported by
3333 the new $_siginfo convenience variable. The feature is currently
3334 implemented on linux ARM, i386 and amd64.
3336 * GDB can now display the VFP floating point registers and NEON vector
3337 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3338 can provide these registers (requires Linux 2.6.30 or later). Remote
3339 and simulator targets may also provide them.
3341 * New remote packets
3344 Search memory for a sequence of bytes.
3347 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3348 operation over reliable transport links. Use of this packet is
3349 controlled by the `set remote noack-packet' command.
3352 Kill the process with the specified process ID. Use this in preference
3353 to `k' when multiprocess protocol extensions are supported.
3356 Obtains additional operating system information
3360 Read or write additional signal information.
3362 * Removed remote protocol undocumented extension
3364 An undocumented extension to the remote protocol's `S' stop reply
3365 packet that permited the stub to pass a process id was removed.
3366 Remote servers should use the `T' stop reply packet instead.
3368 * GDB now supports multiple function calling conventions according to the
3369 DWARF-2 DW_AT_calling_convention function attribute.
3371 * The SH target utilizes the aforementioned change to distinguish between gcc
3372 and Renesas calling convention. It also adds the new CLI commands
3373 `set/show sh calling-convention'.
3375 * GDB can now read compressed debug sections, as produced by GNU gold
3376 with the --compress-debug-sections=zlib flag.
3378 * 64-bit core files are now supported on AIX.
3380 * Thread switching is now supported on Tru64.
3382 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3383 which will be allocated using malloc later in program execution.
3385 * The qXfer:libraries:read remote procotol packet now allows passing a
3386 list of section offsets.
3388 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3389 conditions handling signals delivered during attach or thread creation
3390 have also been fixed.
3392 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3393 From the user's standpoint, all unqualified instances of True and False
3394 are treated as the standard definitions, regardless of context.
3396 * GDB now parses C++ symbol and type names more flexibly. For
3399 template<typename T> class C { };
3402 GDB will now correctly handle all of:
3404 ptype C<char const *>
3405 ptype C<char const*>
3406 ptype C<const char *>
3407 ptype C<const char*>
3409 * New features in the GDB remote stub, gdbserver
3411 - The "--wrapper" command-line argument tells gdbserver to use a
3412 wrapper program to launch programs for debugging.
3414 - On PowerPC and S/390 targets, it is now possible to use a single
3415 gdbserver executable to debug both 32-bit and 64-bit programs.
3416 (This requires gdbserver itself to be built as a 64-bit executable.)
3418 - gdbserver uses the new noack protocol mode for TCP connections to
3419 reduce communications latency, if also supported and enabled in GDB.
3421 - Support for the sparc64-linux-gnu target is now included in
3424 - The amd64-linux build of gdbserver now supports debugging both
3425 32-bit and 64-bit programs.
3427 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3428 now support hardware watchpoints, and will use them automatically
3433 GDB now has support for scripting using Python. Whether this is
3434 available is determined at configure time.
3436 New GDB commands can now be written in Python.
3438 * Ada tasking support
3440 Ada tasks can now be inspected in GDB. The following commands have
3444 Print the list of Ada tasks.
3446 Print detailed information about task number N.
3448 Print the task number of the current task.
3450 Switch the context of debugging to task number N.
3452 * Support for user-defined prefixed commands. The "define" command can
3453 add new commands to existing prefixes, e.g. "target".
3455 * Multi-inferior, multi-process debugging.
3457 GDB now has generalized support for multi-inferior debugging. See
3458 "Debugging Multiple Inferiors" in the manual for more information.
3459 Although availability still depends on target support, the command
3460 set is more uniform now. The GNU/Linux specific multi-forks support
3461 has been migrated to this new framework. This implied some user
3462 visible changes; see "New commands" and also "Removed commands"
3465 * Target descriptions can now describe the target OS ABI. See the
3466 "Target Description Format" section in the user manual for more
3469 * Target descriptions can now describe "compatible" architectures
3470 to indicate that the target can execute applications for a different
3471 architecture in addition to those for the main target architecture.
3472 See the "Target Description Format" section in the user manual for
3475 * Multi-architecture debugging.
3477 GDB now includes general supports for debugging applications on
3478 hybrid systems that use more than one single processor architecture
3479 at the same time. Each such hybrid architecture still requires
3480 specific support to be added. The only hybrid architecture supported
3481 in this version of GDB is the Cell Broadband Engine.
3483 * GDB now supports integrated debugging of Cell/B.E. applications that
3484 use both the PPU and SPU architectures. To enable support for hybrid
3485 Cell/B.E. debugging, you need to configure GDB to support both the
3486 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3487 --enable-targets configure option.
3489 * Non-stop mode debugging.
3491 For some targets, GDB now supports an optional mode of operation in
3492 which you can examine stopped threads while other threads continue
3493 to execute freely. This is referred to as non-stop mode, with the
3494 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3495 section in the user manual for more information.
3497 To be able to support remote non-stop debugging, a remote stub needs
3498 to implement the non-stop mode remote protocol extensions, as
3499 described in the "Remote Non-Stop" section of the user manual. The
3500 GDB remote stub, gdbserver, has been adjusted to support these
3501 extensions on linux targets.
3503 * New commands (for set/show, see "New options" below)
3505 catch syscall [NAME(S) | NUMBER(S)]
3506 Catch system calls. Arguments, which should be names of system
3507 calls or their numbers, mean catch only those syscalls. Without
3508 arguments, every syscall will be caught. When the inferior issues
3509 any of the specified syscalls, GDB will stop and announce the system
3510 call, both when it is called and when its call returns. This
3511 feature is currently available with a native GDB running on the
3512 Linux Kernel, under the following architectures: x86, x86_64,
3513 PowerPC and PowerPC64.
3515 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3517 Search memory for a sequence of bytes.
3519 maint set python print-stack
3520 maint show python print-stack
3521 Show a stack trace when an error is encountered in a Python script.
3524 Invoke CODE by passing it to the Python interpreter.
3529 These allow macros to be defined, undefined, and listed
3533 Show operating system information about processes.
3536 List the inferiors currently under GDB's control.
3539 Switch focus to inferior number NUM.
3542 Detach from inferior number NUM.
3545 Kill inferior number NUM.
3549 set spu stop-on-load
3550 show spu stop-on-load
3551 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3553 set spu auto-flush-cache
3554 show spu auto-flush-cache
3555 Control whether to automatically flush the software-managed cache
3556 during Cell/B.E. debugging.
3558 set sh calling-convention
3559 show sh calling-convention
3560 Control the calling convention used when calling SH target functions.
3563 show debug timestamp
3564 Control display of timestamps with GDB debugging output.
3566 set disassemble-next-line
3567 show disassemble-next-line
3568 Control display of disassembled source lines or instructions when
3571 set remote noack-packet
3572 show remote noack-packet
3573 Set/show the use of remote protocol QStartNoAckMode packet. See above
3574 under "New remote packets."
3576 set remote query-attached-packet
3577 show remote query-attached-packet
3578 Control use of remote protocol `qAttached' (query-attached) packet.
3580 set remote read-siginfo-object
3581 show remote read-siginfo-object
3582 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3585 set remote write-siginfo-object
3586 show remote write-siginfo-object
3587 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3590 set remote reverse-continue
3591 show remote reverse-continue
3592 Control use of remote protocol 'bc' (reverse-continue) packet.
3594 set remote reverse-step
3595 show remote reverse-step
3596 Control use of remote protocol 'bs' (reverse-step) packet.
3598 set displaced-stepping
3599 show displaced-stepping
3600 Control displaced stepping mode. Displaced stepping is a way to
3601 single-step over breakpoints without removing them from the debuggee.
3602 Also known as "out-of-line single-stepping".
3605 show debug displaced
3606 Control display of debugging info for displaced stepping.
3608 maint set internal-error
3609 maint show internal-error
3610 Control what GDB does when an internal error is detected.
3612 maint set internal-warning
3613 maint show internal-warning
3614 Control what GDB does when an internal warning is detected.
3619 Use a wrapper program to launch programs for debugging.
3621 set multiple-symbols (all|ask|cancel)
3622 show multiple-symbols
3623 The value of this variable can be changed to adjust the debugger behavior
3624 when an expression or a breakpoint location contains an ambiguous symbol
3625 name (an overloaded function name, for instance).
3627 set breakpoint always-inserted
3628 show breakpoint always-inserted
3629 Keep breakpoints always inserted in the target, as opposed to inserting
3630 them when resuming the target, and removing them when the target stops.
3631 This option can improve debugger performance on slow remote targets.
3633 set arm fallback-mode (arm|thumb|auto)
3634 show arm fallback-mode
3635 set arm force-mode (arm|thumb|auto)
3637 These commands control how ARM GDB determines whether instructions
3638 are ARM or Thumb. The default for both settings is auto, which uses
3639 the current CPSR value for instructions without symbols; previous
3640 versions of GDB behaved as if "set arm fallback-mode arm".
3642 set disable-randomization
3643 show disable-randomization
3644 Standalone programs run with the virtual address space randomization enabled
3645 by default on some platforms. This option keeps the addresses stable across
3646 multiple debugging sessions.
3650 Control whether other threads are stopped or not when some thread hits
3655 Requests that asynchronous execution is enabled in the target, if available.
3656 In this case, it's possible to resume target in the background, and interact
3657 with GDB while the target is running. "show target-async" displays the
3658 current state of asynchronous execution of the target.
3660 set target-wide-charset
3661 show target-wide-charset
3662 The target-wide-charset is the name of the character set that GDB
3663 uses when printing characters whose type is wchar_t.
3665 set tcp auto-retry (on|off)
3667 set tcp connect-timeout
3668 show tcp connect-timeout
3669 These commands allow GDB to retry failed TCP connections to a remote stub
3670 with a specified timeout period; this is useful if the stub is launched
3671 in parallel with GDB but may not be ready to accept connections immediately.
3673 set libthread-db-search-path
3674 show libthread-db-search-path
3675 Control list of directories which GDB will search for appropriate
3678 set schedule-multiple (on|off)
3679 show schedule-multiple
3680 Allow GDB to resume all threads of all processes or only threads of
3681 the current process.
3685 Use more aggressive caching for accesses to the stack. This improves
3686 performance of remote debugging (particularly backtraces) without
3687 affecting correctness.
3689 set interactive-mode (on|off|auto)
3690 show interactive-mode
3691 Control whether GDB runs in interactive mode (on) or not (off).
3692 When in interactive mode, GDB waits for the user to answer all
3693 queries. Otherwise, GDB does not wait and assumes the default
3694 answer. When set to auto (the default), GDB determines which
3695 mode to use based on the stdin settings.
3700 For program forks, this is replaced by the new more generic `info
3701 inferiors' command. To list checkpoints, you can still use the
3702 `info checkpoints' command, which was an alias for the `info forks'
3706 Replaced by the new `inferior' command. To switch between
3707 checkpoints, you can still use the `restart' command, which was an
3708 alias for the `fork' command.
3711 This is removed, since some targets don't have a notion of
3712 processes. To switch between processes, you can still use the
3713 `inferior' command using GDB's own inferior number.
3716 For program forks, this is replaced by the new more generic `kill
3717 inferior' command. To delete a checkpoint, you can still use the
3718 `delete checkpoint' command, which was an alias for the `delete
3722 For program forks, this is replaced by the new more generic `detach
3723 inferior' command. To detach a checkpoint, you can still use the
3724 `detach checkpoint' command, which was an alias for the `detach
3727 * New native configurations
3729 x86/x86_64 Darwin i[34567]86-*-darwin*
3731 x86_64 MinGW x86_64-*-mingw*
3735 Lattice Mico32 lm32-*
3736 x86 DICOS i[34567]86-*-dicos*
3737 x86_64 DICOS x86_64-*-dicos*
3740 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3741 (mingw32ce) debugging.
3747 These commands were actually not implemented on any target.
3749 *** Changes in GDB 6.8
3751 * New native configurations
3753 NetBSD/hppa hppa*-*netbsd*
3754 Xtensa GNU/Linux xtensa*-*-linux*
3758 NetBSD/hppa hppa*-*-netbsd*
3759 Xtensa GNU/Lunux xtensa*-*-linux*
3761 * Change in command line behavior -- corefiles vs. process ids.
3763 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3764 attaching to process NUMBER fails, GDB no longer attempts to open a
3765 core file named NUMBER. Attaching to a program using the -c option
3766 is no longer supported. Instead, use the '-p' or '--pid' options.
3768 * GDB can now be built as a native debugger for debugging Windows x86
3769 (mingw32) Portable Executable (PE) programs.
3771 * Pending breakpoints no longer change their number when their address
3774 * GDB now supports breakpoints with multiple locations,
3775 including breakpoints on C++ constructors, inside C++ templates,
3776 and in inlined functions.
3778 * GDB's ability to debug optimized code has been improved. GDB more
3779 accurately identifies function bodies and lexical blocks that occupy
3780 more than one contiguous range of addresses.
3782 * Target descriptions can now describe registers for PowerPC.
3784 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3785 registers on PowerPC targets.
3787 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3788 targets even when the libthread_db library is not available.
3790 * The GDB remote stub, gdbserver, now supports the new file transfer
3791 commands (remote put, remote get, and remote delete).
3793 * The GDB remote stub, gdbserver, now supports run and attach in
3794 extended-remote mode.
3796 * hppa*64*-*-hpux11* target broken
3797 The debugger is unable to start a program and fails with the following
3798 error: "Error trying to get information about dynamic linker".
3799 The gdb-6.7 release is also affected.
3801 * GDB now supports the --enable-targets= configure option to allow
3802 building a single GDB executable that supports multiple remote
3803 target architectures.
3805 * GDB now supports debugging C and C++ programs which use the
3806 Decimal Floating Point extension. In addition, the PowerPC target
3807 now has a set of pseudo-registers to inspect decimal float values
3808 stored in two consecutive float registers.
3810 * The -break-insert MI command can optionally create pending
3813 * Improved support for debugging Ada
3814 Many improvements to the Ada language support have been made. These
3816 - Better support for Ada2005 interface types
3817 - Improved handling of arrays and slices in general
3818 - Better support for Taft-amendment types
3819 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3821 - Improved command completion in Ada
3824 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3829 set print frame-arguments (all|scalars|none)
3830 show print frame-arguments
3831 The value of this variable can be changed to control which argument
3832 values should be printed by the debugger when displaying a frame.
3837 Transfer files to and from a remote target, and delete remote files.
3844 Transfer files to and from a remote target, and delete remote files.
3846 * New remote packets
3853 Open, close, read, write, and delete files on the remote system.
3856 Attach to an existing process on the remote system, in extended-remote
3860 Run a new process on the remote system, in extended-remote mode.
3862 *** Changes in GDB 6.7
3864 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3865 bfd, libiberty and opcodes, as revealed by static analysis donated by
3866 Coverity, Inc. (http://scan.coverity.com).
3868 * When looking up multiply-defined global symbols, GDB will now prefer the
3869 symbol definition in the current shared library if it was built using the
3870 -Bsymbolic linker option.
3872 * When the Text User Interface (TUI) is not configured, GDB will now
3873 recognize the -tui command-line option and print a message that the TUI
3876 * The GDB remote stub, gdbserver, now has lower overhead for high
3877 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
3879 * GDB for MIPS targets now autodetects whether a remote target provides
3880 32-bit or 64-bit register values.
3882 * Support for C++ member pointers has been improved.
3884 * GDB now understands XML target descriptions, which specify the
3885 target's overall architecture. GDB can read a description from
3886 a local file or over the remote serial protocol.
3888 * Vectors of single-byte data use a new integer type which is not
3889 automatically displayed as character or string data.
3891 * The /s format now works with the print command. It displays
3892 arrays of single-byte integers and pointers to single-byte integers
3895 * Target descriptions can now describe target-specific registers,
3896 for architectures which have implemented the support (currently
3897 only ARM, M68K, and MIPS).
3899 * GDB and the GDB remote stub, gdbserver, now support the XScale
3902 * The GDB remote stub, gdbserver, has been updated to support
3903 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
3904 has been rewritten to use the standard GDB remote protocol.
3906 * GDB can now step into C++ functions which are called through thunks.
3908 * GDB for the Cell/B.E. SPU now supports overlay debugging.
3910 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
3911 layout. It also supports a TextSeg= and DataSeg= response when only
3912 segment base addresses (rather than offsets) are available.
3914 * The /i format now outputs any trailing branch delay slot instructions
3915 immediately following the last instruction within the count specified.
3917 * The GDB remote protocol "T" stop reply packet now supports a
3918 "library" response. Combined with the new "qXfer:libraries:read"
3919 packet, this response allows GDB to debug shared libraries on targets
3920 where the operating system manages the list of loaded libraries (e.g.
3921 Windows and SymbianOS).
3923 * The GDB remote stub, gdbserver, now supports dynamic link libraries
3924 (DLLs) on Windows and Windows CE targets.
3926 * GDB now supports a faster verification that a .debug file matches its binary
3927 according to its build-id signature, if the signature is present.
3933 Enable or disable hardware flow control (RTS/CTS) on the serial port
3934 when debugging using remote targets.
3936 set mem inaccessible-by-default
3937 show mem inaccessible-by-default
3938 If the target supplies a memory map, for instance via the remote
3939 protocol's "qXfer:memory-map:read" packet, setting this variable
3940 prevents GDB from accessing memory outside the memory map. This
3941 is useful for targets with memory mapped registers or which react
3942 badly to accesses of unmapped address space.
3944 set breakpoint auto-hw
3945 show breakpoint auto-hw
3946 If the target supplies a memory map, for instance via the remote
3947 protocol's "qXfer:memory-map:read" packet, setting this variable
3948 lets GDB use hardware breakpoints automatically for memory regions
3949 where it can not use software breakpoints. This covers both the
3950 "break" command and internal breakpoints used for other commands
3951 including "next" and "finish".
3954 catch exception unhandled
3955 Stop the program execution when Ada exceptions are raised.
3958 Stop the program execution when an Ada assertion failed.
3962 Set an alternate system root for target files. This is a more
3963 general version of "set solib-absolute-prefix", which is now
3964 an alias to "set sysroot".
3967 Provide extended SPU facility status information. This set of
3968 commands is available only when debugging the Cell/B.E. SPU
3971 * New native configurations
3973 OpenBSD/sh sh*-*openbsd*
3976 unset tdesc filename
3978 Use the specified local file as an XML target description, and do
3979 not query the target for its built-in description.
3983 OpenBSD/sh sh*-*-openbsd*
3984 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
3985 Toshiba Media Processor mep-elf
3987 * New remote packets
3990 Ignore the specified signals; pass them directly to the debugged program
3991 without stopping other threads or reporting them to GDB.
3993 qXfer:features:read:
3994 Read an XML target description from the target, which describes its
3999 Read or write contents of an spufs file on the target system. These
4000 packets are available only on the Cell/B.E. SPU architecture.
4002 qXfer:libraries:read:
4003 Report the loaded shared libraries. Combined with new "T" packet
4004 response, this packet allows GDB to debug shared libraries on
4005 targets where the operating system manages the list of loaded
4006 libraries (e.g. Windows and SymbianOS).
4010 Support for these obsolete configurations has been removed.
4018 i[34567]86-*-lynxos*
4019 i[34567]86-*-netware*
4020 i[34567]86-*-sco3.2v5*
4021 i[34567]86-*-sco3.2v4*
4023 i[34567]86-*-sysv4.2*
4026 i[34567]86-*-unixware2*
4027 i[34567]86-*-unixware*
4036 * Other removed features
4043 Various m68k-only ROM monitors.
4050 Various Renesas ROM monitors and debugging interfaces for SH and
4055 Support for a Macraigor serial interface to on-chip debugging.
4056 GDB does not directly support the newer parallel or USB
4061 A debug information format. The predecessor to DWARF 2 and
4062 DWARF 3, which are still supported.
4064 Support for the HP aCC compiler on HP-UX/PA-RISC
4066 SOM-encapsulated symbolic debugging information, automatic
4067 invocation of pxdb, and the aCC custom C++ ABI. This does not
4068 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4069 with aCC can still be debugged on an assembly level.
4071 MIPS ".pdr" sections
4073 A MIPS-specific format used to describe stack frame layout
4074 in debugging information.
4078 GDB could work with an older version of Guile to debug
4079 the interpreter and Scheme programs running in it.
4081 set mips stack-arg-size
4082 set mips saved-gpreg-size
4084 Use "set mips abi" to control parameter passing for MIPS.
4086 *** Changes in GDB 6.6
4091 Cell Broadband Engine SPU spu-elf
4093 * GDB can now be configured as a cross-debugger targeting native Windows
4094 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4095 running on a Windows system over TCP/IP to debug Windows programs.
4097 * The GDB remote stub, gdbserver, has been updated to support Windows and
4098 Cygwin debugging. Both single-threaded and multi-threaded programs are
4101 * The "set trust-readonly-sections" command works again. This command was
4102 broken in GDB 6.3, 6.4, and 6.5.
4104 * The "load" command now supports writing to flash memory, if the remote
4105 stub provides the required support.
4107 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4108 longer requires symbolic debug information (e.g. DWARF-2).
4113 unset substitute-path
4114 show substitute-path
4115 Manage a list of substitution rules that GDB uses to rewrite the name
4116 of the directories where the sources are located. This can be useful
4117 for instance when the sources were moved to a different location
4118 between compilation and debugging.
4122 Print each CLI command as it is executed. Each command is prefixed with
4123 a number of `+' symbols representing the nesting depth.
4124 The source command now has a `-v' option to enable the same feature.
4128 The ARM Demon monitor support (RDP protocol, "target rdp").
4130 Kernel Object Display, an embedded debugging feature which only worked with
4131 an obsolete version of Cisco IOS.
4133 The 'set download-write-size' and 'show download-write-size' commands.
4135 * New remote packets
4138 Tell a stub about GDB client features, and request remote target features.
4139 The first feature implemented is PacketSize, which allows the target to
4140 specify the size of packets it can handle - to minimize the number of
4141 packets required and improve performance when connected to a remote
4145 Fetch an OS auxilliary vector from the remote stub. This packet is a
4146 more efficient replacement for qPart:auxv:read.
4148 qXfer:memory-map:read:
4149 Fetch a memory map from the remote stub, including information about
4150 RAM, ROM, and flash memory devices.
4155 Erase and program a flash memory device.
4157 * Removed remote packets
4160 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4161 used it, and only gdbserver implemented it.
4163 *** Changes in GDB 6.5
4167 Renesas M32C/M16C m32c-elf
4169 Morpho Technologies ms1 ms1-elf
4173 init-if-undefined Initialize a convenience variable, but
4174 only if it doesn't already have a value.
4176 The following commands are presently only implemented for native GNU/Linux:
4178 checkpoint Save a snapshot of the program state.
4180 restart <n> Return the program state to a
4181 previously saved state.
4183 info checkpoints List currently saved checkpoints.
4185 delete-checkpoint <n> Delete a previously saved checkpoint.
4187 set|show detach-on-fork Tell gdb whether to detach from a newly
4188 forked process, or to keep debugging it.
4190 info forks List forks of the user program that
4191 are available to be debugged.
4193 fork <n> Switch to debugging one of several
4194 forks of the user program that are
4195 available to be debugged.
4197 delete-fork <n> Delete a fork from the list of forks
4198 that are available to be debugged (and
4199 kill the forked process).
4201 detach-fork <n> Delete a fork from the list of forks
4202 that are available to be debugged (and
4203 allow the process to continue).
4207 Morpho Technologies ms2 ms1-elf
4209 * Improved Windows host support
4211 GDB now builds as a cross debugger hosted on i686-mingw32, including
4212 native console support, and remote communications using either
4213 network sockets or serial ports.
4215 * Improved Modula-2 language support
4217 GDB can now print most types in the Modula-2 syntax. This includes:
4218 basic types, set types, record types, enumerated types, range types,
4219 pointer types and ARRAY types. Procedure var parameters are correctly
4220 printed and hexadecimal addresses and character constants are also
4221 written in the Modula-2 syntax. Best results can be obtained by using
4222 GNU Modula-2 together with the -gdwarf-2 command line option.
4226 The ARM rdi-share module.
4228 The Netware NLM debug server.
4230 *** Changes in GDB 6.4
4232 * New native configurations
4234 OpenBSD/arm arm*-*-openbsd*
4235 OpenBSD/mips64 mips64-*-openbsd*
4239 Morpho Technologies ms1 ms1-elf
4241 * New command line options
4243 --batch-silent As for --batch, but totally silent.
4244 --return-child-result The debugger will exist with the same value
4245 the child (debugged) program exited with.
4246 --eval-command COMMAND, -ex COMMAND
4247 Execute a single GDB CLI command. This may be
4248 specified multiple times and in conjunction
4249 with the --command (-x) option.
4251 * Deprecated commands removed
4253 The following commands, that were deprecated in 2000, have been
4257 set|show arm disassembly-flavor set|show arm disassembler
4258 othernames set arm disassembler
4259 set|show remotedebug set|show debug remote
4260 set|show archdebug set|show debug arch
4261 set|show eventdebug set|show debug event
4264 * New BSD user-level threads support
4266 It is now possible to debug programs using the user-level threads
4267 library on OpenBSD and FreeBSD. Currently supported (target)
4270 FreeBSD/amd64 x86_64-*-freebsd*
4271 FreeBSD/i386 i386-*-freebsd*
4272 OpenBSD/i386 i386-*-openbsd*
4274 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4275 are not yet supported.
4277 * New support for Matsushita MN10300 w/sim added
4278 (Work in progress). mn10300-elf.
4280 * REMOVED configurations and files
4282 VxWorks and the XDR protocol *-*-vxworks
4283 Motorola MCORE mcore-*-*
4284 National Semiconductor NS32000 ns32k-*-*
4286 * New "set print array-indexes" command
4288 After turning this setting "on", GDB prints the index of each element
4289 when displaying arrays. The default is "off" to preserve the previous
4292 * VAX floating point support
4294 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4296 * User-defined command support
4298 In addition to using $arg0..$arg9 for argument passing, it is now possible
4299 to use $argc to determine now many arguments have been passed. See the
4300 section on user-defined commands in the user manual for more information.
4302 *** Changes in GDB 6.3:
4304 * New command line option
4306 GDB now accepts -l followed by a number to set the timeout for remote
4309 * GDB works with GCC -feliminate-dwarf2-dups
4311 GDB now supports a more compact representation of DWARF-2 debug
4312 information using DW_FORM_ref_addr references. These are produced
4313 by GCC with the option -feliminate-dwarf2-dups and also by some
4314 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4315 to use -feliminate-dwarf2-dups.
4317 * Internationalization
4319 When supported by the host system, GDB will be built with
4320 internationalization (libintl). The task of marking up the sources is
4321 continued, we're looking forward to our first translation.
4325 Initial support for debugging programs compiled with the GNAT
4326 implementation of the Ada programming language has been integrated
4327 into GDB. In this release, support is limited to expression evaluation.
4329 * New native configurations
4331 GNU/Linux/m32r m32r-*-linux-gnu
4335 GDB's remote protocol now includes support for the 'p' packet. This
4336 packet is used to fetch individual registers from a remote inferior.
4338 * END-OF-LIFE registers[] compatibility module
4340 GDB's internal register infrastructure has been completely rewritten.
4341 The new infrastructure making possible the implementation of key new
4342 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4345 GDB 6.3 will be the last release to include the the registers[]
4346 compatibility module that allowed out-of-date configurations to
4347 continue to work. This change directly impacts the following
4357 powerpc bdm protocol
4359 Unless there is activity to revive these configurations, they will be
4360 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4362 * OBSOLETE configurations and files
4364 Configurations that have been declared obsolete in this release have
4365 been commented out. Unless there is activity to revive these
4366 configurations, the next release of GDB will have their sources
4367 permanently REMOVED.
4376 *** Changes in GDB 6.2.1:
4378 * MIPS `break main; run' gave an heuristic-fence-post warning
4380 When attempting to run even a simple program, a warning about
4381 heuristic-fence-post being hit would be reported. This problem has
4384 * MIPS IRIX 'long double' crashed GDB
4386 When examining a long double variable, GDB would get a segmentation
4387 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4388 IRIX long double values).
4392 A bug in the VAX stack code was causing problems with the "next"
4393 command. This problem has been fixed.
4395 *** Changes in GDB 6.2:
4397 * Fix for ``many threads''
4399 On GNU/Linux systems that use the NPTL threads library, a program
4400 rapidly creating and deleting threads would confuse GDB leading to the
4403 ptrace: No such process.
4404 thread_db_get_info: cannot get thread info: generic error
4406 This problem has been fixed.
4408 * "-async" and "-noasync" options removed.
4410 Support for the broken "-noasync" option has been removed (it caused
4413 * New ``start'' command.
4415 This command runs the program until the begining of the main procedure.
4417 * New BSD Kernel Data Access Library (libkvm) interface
4419 Using ``target kvm'' it is now possible to debug kernel core dumps and
4420 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4421 platforms. Currently supported (native-only) configurations are:
4423 FreeBSD/amd64 x86_64-*-freebsd*
4424 FreeBSD/i386 i?86-*-freebsd*
4425 NetBSD/i386 i?86-*-netbsd*
4426 NetBSD/m68k m68*-*-netbsd*
4427 NetBSD/sparc sparc-*-netbsd*
4428 OpenBSD/amd64 x86_64-*-openbsd*
4429 OpenBSD/i386 i?86-*-openbsd*
4430 OpenBSD/m68k m68*-openbsd*
4431 OpenBSD/sparc sparc-*-openbsd*
4433 * Signal trampoline code overhauled
4435 Many generic problems with GDB's signal handling code have been fixed.
4436 These include: backtraces through non-contiguous stacks; recognition
4437 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4438 call; backtrace through a signal trampoline; step into and out of
4439 signal handlers; and single-stepping in the signal trampoline.
4441 Please note that kernel bugs are a limiting factor here. These
4442 features have been shown to work on an s390 GNU/Linux system that
4443 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4445 * Cygwin support for DWARF 2 added.
4447 * New native configurations
4449 GNU/Linux/hppa hppa*-*-linux*
4450 OpenBSD/hppa hppa*-*-openbsd*
4451 OpenBSD/m68k m68*-*-openbsd*
4452 OpenBSD/m88k m88*-*-openbsd*
4453 OpenBSD/powerpc powerpc-*-openbsd*
4454 NetBSD/vax vax-*-netbsd*
4455 OpenBSD/vax vax-*-openbsd*
4457 * END-OF-LIFE frame compatibility module
4459 GDB's internal frame infrastructure has been completely rewritten.
4460 The new infrastructure making it possible to support key new features
4461 including DWARF 2 Call Frame Information. To aid in the task of
4462 migrating old configurations to this new infrastructure, a
4463 compatibility module, that allowed old configurations to continue to
4464 work, was also included.
4466 GDB 6.2 will be the last release to include this frame compatibility
4467 module. This change directly impacts the following configurations:
4477 Unless there is activity to revive these configurations, they will be
4478 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4480 * REMOVED configurations and files
4482 Sun 3, running SunOS 3 m68*-*-sunos3*
4483 Sun 3, running SunOS 4 m68*-*-sunos4*
4484 Sun 2, running SunOS 3 m68000-*-sunos3*
4485 Sun 2, running SunOS 4 m68000-*-sunos4*
4486 Motorola 680x0 running LynxOS m68*-*-lynxos*
4487 AT&T 3b1/Unix pc m68*-att-*
4488 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4489 decstation mips-dec-* mips-little-*
4490 riscos mips-*-riscos* mips-*-sysv*
4491 sonymips mips-sony-*
4492 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4494 *** Changes in GDB 6.1.1:
4496 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4498 The TUI (Text-mode User Interface) is now built as part of a default
4499 GDB configuration. It is enabled by either selecting the TUI with the
4500 command line option "-i=tui" or by running the separate "gdbtui"
4501 program. For more information on the TUI, see the manual "Debugging
4504 * Pending breakpoint support (also included in GDB 6.1)
4506 Support has been added to allow you to specify breakpoints in shared
4507 libraries that have not yet been loaded. If a breakpoint location
4508 cannot be found, and the "breakpoint pending" option is set to auto,
4509 GDB queries you if you wish to make the breakpoint pending on a future
4510 shared-library load. If and when GDB resolves the breakpoint symbol,
4511 the pending breakpoint is removed as one or more regular breakpoints
4514 Pending breakpoints are very useful for GCJ Java debugging.
4516 * Fixed ISO-C build problems
4518 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4519 non ISO-C code that stopped them being built using a more strict ISO-C
4520 compiler (e.g., IBM's C compiler).
4522 * Fixed build problem on IRIX 5
4524 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4525 wasn't able to compile compile on an IRIX 5 system.
4527 * Added execute permission to gdb/gdbserver/configure
4529 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4530 permission. This bug would cause configure to fail on a number of
4531 systems (Solaris, IRIX). Ref: server/519.
4533 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4535 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4536 has been updated to use constant array sizes.
4538 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4540 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4541 its generated DWARF Call Frame Info. This encoding was causing GDB to
4542 panic, that panic has been fixed. Ref: gdb/1628.
4544 * Fixed a problem when examining parameters in shared library code.
4546 When examining parameters in optimized shared library code generated
4547 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4548 not available''. GDB now correctly displays the variable's value.
4550 *** Changes in GDB 6.1:
4552 * Removed --with-mmalloc
4554 Support for the mmalloc memory manager has been removed, as it
4555 conflicted with the internal gdb byte cache.
4557 * Changes in AMD64 configurations
4559 The AMD64 target now includes the %cs and %ss registers. As a result
4560 the AMD64 remote protocol has changed; this affects the floating-point
4561 and SSE registers. If you rely on those registers for your debugging,
4562 you should upgrade gdbserver on the remote side.
4564 * Revised SPARC target
4566 The SPARC target has been completely revised, incorporating the
4567 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4568 support for LynxOS and SunOS 4 has been dropped. Calling functions
4569 from within GDB on operating systems with a non-executable stack
4570 (Solaris, OpenBSD) now works.
4574 GDB has a new C++ demangler which does a better job on the mangled
4575 names generated by current versions of g++. It also runs faster, so
4576 with this and other changes gdb should now start faster on large C++
4579 * DWARF 2 Location Expressions
4581 GDB support for location expressions has been extended to support function
4582 arguments and frame bases. Older versions of GDB could crash when they
4585 * C++ nested types and namespaces
4587 GDB's support for nested types and namespaces in C++ has been
4588 improved, especially if you use the DWARF 2 debugging format. (This
4589 is the default for recent versions of GCC on most platforms.)
4590 Specifically, if you have a class "Inner" defined within a class or
4591 namespace "Outer", then GDB realizes that the class's name is
4592 "Outer::Inner", not simply "Inner". This should greatly reduce the
4593 frequency of complaints about not finding RTTI symbols. In addition,
4594 if you are stopped at inside of a function defined within a namespace,
4595 GDB modifies its name lookup accordingly.
4597 * New native configurations
4599 NetBSD/amd64 x86_64-*-netbsd*
4600 OpenBSD/amd64 x86_64-*-openbsd*
4601 OpenBSD/alpha alpha*-*-openbsd*
4602 OpenBSD/sparc sparc-*-openbsd*
4603 OpenBSD/sparc64 sparc64-*-openbsd*
4605 * New debugging protocols
4607 M32R with SDI protocol m32r-*-elf*
4609 * "set prompt-escape-char" command deleted.
4611 The command "set prompt-escape-char" has been deleted. This command,
4612 and its very obscure effet on GDB's prompt, was never documented,
4613 tested, nor mentioned in the NEWS file.
4615 * OBSOLETE configurations and files
4617 Configurations that have been declared obsolete in this release have
4618 been commented out. Unless there is activity to revive these
4619 configurations, the next release of GDB will have their sources
4620 permanently REMOVED.
4622 Sun 3, running SunOS 3 m68*-*-sunos3*
4623 Sun 3, running SunOS 4 m68*-*-sunos4*
4624 Sun 2, running SunOS 3 m68000-*-sunos3*
4625 Sun 2, running SunOS 4 m68000-*-sunos4*
4626 Motorola 680x0 running LynxOS m68*-*-lynxos*
4627 AT&T 3b1/Unix pc m68*-att-*
4628 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4629 decstation mips-dec-* mips-little-*
4630 riscos mips-*-riscos* mips-*-sysv*
4631 sonymips mips-sony-*
4632 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4634 * REMOVED configurations and files
4636 SGI Irix-4.x mips-sgi-irix4 or iris4
4637 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4638 Z8000 simulator z8k-zilog-none or z8ksim
4639 Matsushita MN10200 w/simulator mn10200-*-*
4640 H8/500 simulator h8500-hitachi-hms or h8500hms
4641 HP/PA running BSD hppa*-*-bsd*
4642 HP/PA running OSF/1 hppa*-*-osf*
4643 HP/PA Pro target hppa*-*-pro*
4644 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4645 386BSD i[3456]86-*-bsd*
4646 Sequent family i[3456]86-sequent-sysv4*
4647 i[3456]86-sequent-sysv*
4648 i[3456]86-sequent-bsd*
4649 SPARC running LynxOS sparc-*-lynxos*
4650 SPARC running SunOS 4 sparc-*-sunos4*
4651 Tsqware Sparclet sparclet-*-*
4652 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4654 *** Changes in GDB 6.0:
4658 Support for debugging the Objective-C programming language has been
4659 integrated into GDB.
4661 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4663 DWARF 2's Call Frame Information makes available compiler generated
4664 information that more exactly describes the program's run-time stack.
4665 By using this information, GDB is able to provide more robust stack
4668 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4669 have been updated to use a new backtrace mechanism which includes
4670 DWARF 2 CFI support.
4674 GDB's remote protocol has been extended to include support for hosted
4675 file I/O (where the remote target uses GDB's file system). See GDB's
4676 remote protocol documentation for details.
4678 * All targets using the new architecture framework.
4680 All of GDB's targets have been updated to use the new internal
4681 architecture framework. The way is now open for future GDB releases
4682 to include cross-architecture native debugging support (i386 on amd64,
4685 * GNU/Linux's Thread Local Storage (TLS)
4687 GDB now includes support for for the GNU/Linux implementation of
4688 per-thread variables.
4690 * GNU/Linux's Native POSIX Thread Library (NPTL)
4692 GDB's thread code has been updated to work with either the new
4693 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4695 * Separate debug info.
4697 GDB, in conjunction with BINUTILS, now supports a mechanism for
4698 automatically loading debug information from a separate file. Instead
4699 of shipping full debug and non-debug versions of system libraries,
4700 system integrators can now instead ship just the stripped libraries
4701 and optional debug files.
4703 * DWARF 2 Location Expressions
4705 DWARF 2 Location Expressions allow the compiler to more completely
4706 describe the location of variables (even in optimized code) to the
4709 GDB now includes preliminary support for location expressions (support
4710 for DW_OP_piece is still missing).
4714 A number of long standing bugs that caused GDB to die while starting a
4715 Java application have been fixed. GDB's Java support is now
4716 considered "useable".
4718 * GNU/Linux support for fork, vfork, and exec.
4720 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4721 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4724 * GDB supports logging output to a file
4726 There are two new commands, "set logging" and "show logging", which can be
4727 used to capture GDB's output to a file.
4729 * The meaning of "detach" has changed for gdbserver
4731 The "detach" command will now resume the application, as documented. To
4732 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4735 * d10v, m68hc11 `regs' command deprecated
4737 The `info registers' command has been updated so that it displays the
4738 registers using a format identical to the old `regs' command.
4742 A new command, "maint set profile on/off", has been added. This command can
4743 be used to enable or disable profiling while running GDB, to profile a
4744 session or a set of commands. In addition there is a new configure switch,
4745 "--enable-profiling", which will cause GDB to be compiled with profiling
4746 data, for more informative profiling results.
4748 * Default MI syntax changed to "mi2".
4750 The default MI (machine interface) syntax, enabled by the command line
4751 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4752 "mi1", can be enabled by specifying the option "-i=mi1".
4754 Support for the original "mi0" syntax (included in GDB 5.0) has been
4757 Fix for gdb/192: removed extraneous space when displaying frame level.
4758 Fix for gdb/672: update changelist is now output in mi list format.
4759 Fix for gdb/702: a -var-assign that updates the value now shows up
4760 in a subsequent -var-update.
4762 * New native configurations.
4764 FreeBSD/amd64 x86_64-*-freebsd*
4766 * Multi-arched targets.
4768 HP/PA HPUX11 hppa*-*-hpux*
4769 Renesas M32R/D w/simulator m32r-*-elf*
4771 * OBSOLETE configurations and files
4773 Configurations that have been declared obsolete in this release have
4774 been commented out. Unless there is activity to revive these
4775 configurations, the next release of GDB will have their sources
4776 permanently REMOVED.
4778 Z8000 simulator z8k-zilog-none or z8ksim
4779 Matsushita MN10200 w/simulator mn10200-*-*
4780 H8/500 simulator h8500-hitachi-hms or h8500hms
4781 HP/PA running BSD hppa*-*-bsd*
4782 HP/PA running OSF/1 hppa*-*-osf*
4783 HP/PA Pro target hppa*-*-pro*
4784 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4785 Sequent family i[3456]86-sequent-sysv4*
4786 i[3456]86-sequent-sysv*
4787 i[3456]86-sequent-bsd*
4788 Tsqware Sparclet sparclet-*-*
4789 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4791 * REMOVED configurations and files
4794 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4795 IBM AIX PS/2 i[3456]86-*-aix
4796 i386 running Mach 3.0 i[3456]86-*-mach3*
4797 i386 running Mach i[3456]86-*-mach*
4798 i386 running OSF/1 i[3456]86-*osf1mk*
4799 HP/Apollo 68k Family m68*-apollo*-sysv*,
4801 m68*-hp-bsd*, m68*-hp-hpux*
4802 Argonaut Risc Chip (ARC) arc-*-*
4803 Mitsubishi D30V d30v-*-*
4804 Fujitsu FR30 fr30-*-elf*
4805 OS/9000 i[34]86-*-os9k
4806 I960 with MON960 i960-*-coff
4808 * MIPS $fp behavior changed
4810 The convenience variable $fp, for the MIPS, now consistently returns
4811 the address of the current frame's base. Previously, depending on the
4812 context, $fp could refer to either $sp or the current frame's base
4813 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4814 The GNU Source-Level Debugger''.
4816 *** Changes in GDB 5.3:
4818 * GNU/Linux shared library multi-threaded performance improved.
4820 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4821 `/proc', in preference to `ptrace' for memory reads. This may result
4822 in an improvement in the start-up time of multi-threaded, shared
4823 library applications when run under GDB. One GDB user writes: ``loads
4824 shared libs like mad''.
4826 * ``gdbserver'' now supports multi-threaded applications on some targets
4828 Support for debugging multi-threaded applications which use
4829 the GNU/Linux LinuxThreads package has been added for
4830 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4831 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4833 * GDB now supports C/C++ preprocessor macros.
4835 GDB now expands preprocessor macro invocations in C/C++ expressions,
4836 and provides various commands for showing macro definitions and how
4839 The new command `macro expand EXPRESSION' expands any macro
4840 invocations in expression, and shows the result.
4842 The new command `show macro MACRO-NAME' shows the definition of the
4843 macro named MACRO-NAME, and where it was defined.
4845 Most compilers don't include information about macros in the debugging
4846 information by default. In GCC 3.1, for example, you need to compile
4847 your program with the options `-gdwarf-2 -g3'. If the macro
4848 information is present in the executable, GDB will read it.
4850 * Multi-arched targets.
4852 DEC Alpha (partial) alpha*-*-*
4853 DEC VAX (partial) vax-*-*
4855 National Semiconductor NS32000 (partial) ns32k-*-*
4856 Motorola 68000 (partial) m68k-*-*
4857 Motorola MCORE mcore-*-*
4861 Fujitsu FRV architecture added by Red Hat frv*-*-*
4864 * New native configurations
4866 Alpha NetBSD alpha*-*-netbsd*
4867 SH NetBSD sh*-*-netbsdelf*
4868 MIPS NetBSD mips*-*-netbsd*
4869 UltraSPARC NetBSD sparc64-*-netbsd*
4871 * OBSOLETE configurations and files
4873 Configurations that have been declared obsolete in this release have
4874 been commented out. Unless there is activity to revive these
4875 configurations, the next release of GDB will have their sources
4876 permanently REMOVED.
4878 Mitsubishi D30V d30v-*-*
4879 OS/9000 i[34]86-*-os9k
4880 IBM AIX PS/2 i[3456]86-*-aix
4881 Fujitsu FR30 fr30-*-elf*
4882 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4883 Argonaut Risc Chip (ARC) arc-*-*
4884 i386 running Mach 3.0 i[3456]86-*-mach3*
4885 i386 running Mach i[3456]86-*-mach*
4886 i386 running OSF/1 i[3456]86-*osf1mk*
4887 HP/Apollo 68k Family m68*-apollo*-sysv*,
4889 m68*-hp-bsd*, m68*-hp-hpux*
4890 I960 with MON960 i960-*-coff
4892 * OBSOLETE languages
4894 CHILL, a Pascal like language used by telecommunications companies.
4896 * REMOVED configurations and files
4898 AMD 29k family via UDI a29k-amd-udi, udi29k
4899 A29K VxWorks a29k-*-vxworks
4900 AMD 29000 embedded, using EBMON a29k-none-none
4901 AMD 29000 embedded with COFF a29k-none-coff
4902 AMD 29000 embedded with a.out a29k-none-aout
4904 testsuite/gdb.hp/gdb.threads-hp/ directory
4906 * New command "set max-user-call-depth <nnn>"
4908 This command allows the user to limit the call depth of user-defined
4909 commands. The default is 1024.
4911 * Changes in FreeBSD/i386 native debugging.
4913 Support for the "generate-core-file" has been added.
4915 * New commands "dump", "append", and "restore".
4917 These commands allow data to be copied from target memory
4918 to a bfd-format or binary file (dump and append), and back
4919 from a file into memory (restore).
4921 * Improved "next/step" support on multi-processor Alpha Tru64.
4923 The previous single-step mechanism could cause unpredictable problems,
4924 including the random appearance of SIGSEGV or SIGTRAP signals. The use
4925 of a software single-step mechanism prevents this.
4927 *** Changes in GDB 5.2.1:
4935 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
4936 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
4937 Fix, by Joel Brobecker imported from mainline.
4939 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
4940 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
4941 Fix, by Fred Fish, imported from mainline.
4943 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
4944 Surprisingly enough, it works now.
4945 By Michal Ludvig, imported from mainline.
4947 i386 hardware watchpoint support:
4948 avoid misses on second run for some targets.
4949 By Pierre Muller, imported from mainline.
4951 *** Changes in GDB 5.2:
4953 * New command "set trust-readonly-sections on[off]".
4955 This command is a hint that tells gdb that read-only sections
4956 really are read-only (ie. that their contents will not change).
4957 In this mode, gdb will go to the object file rather than the
4958 target to read memory from read-only sections (such as ".text").
4959 This can be a significant performance improvement on some
4960 (notably embedded) targets.
4962 * New command "generate-core-file" (or "gcore").
4964 This new gdb command allows the user to drop a core file of the child
4965 process state at any time. So far it's been implemented only for
4966 GNU/Linux and Solaris, but should be relatively easily ported to other
4967 hosts. Argument is core file name (defaults to core.<pid>).
4969 * New command line option
4971 GDB now accepts --pid or -p followed by a process id.
4973 * Change in command line behavior -- corefiles vs. process ids.
4975 There is a subtle behavior in the way in which GDB handles
4976 command line arguments. The first non-flag argument is always
4977 a program to debug, but the second non-flag argument may either
4978 be a corefile or a process id. Previously, GDB would attempt to
4979 open the second argument as a corefile, and if that failed, would
4980 issue a superfluous error message and then attempt to attach it as
4981 a process. Now, if the second argument begins with a non-digit,
4982 it will be treated as a corefile. If it begins with a digit,
4983 GDB will attempt to attach it as a process, and if no such process
4984 is found, will then attempt to open it as a corefile.
4986 * Changes in ARM configurations.
4988 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
4989 configuration is fully multi-arch.
4991 * New native configurations
4993 ARM NetBSD arm*-*-netbsd*
4994 x86 OpenBSD i[3456]86-*-openbsd*
4995 AMD x86-64 running GNU/Linux x86_64-*-linux-*
4996 Sparc64 running FreeBSD sparc64-*-freebsd*
5000 Sanyo XStormy16 xstormy16-elf
5002 * OBSOLETE configurations and files
5004 Configurations that have been declared obsolete in this release have
5005 been commented out. Unless there is activity to revive these
5006 configurations, the next release of GDB will have their sources
5007 permanently REMOVED.
5009 AMD 29k family via UDI a29k-amd-udi, udi29k
5010 A29K VxWorks a29k-*-vxworks
5011 AMD 29000 embedded, using EBMON a29k-none-none
5012 AMD 29000 embedded with COFF a29k-none-coff
5013 AMD 29000 embedded with a.out a29k-none-aout
5015 testsuite/gdb.hp/gdb.threads-hp/ directory
5017 * REMOVED configurations and files
5019 TI TMS320C80 tic80-*-*
5021 PowerPC Solaris powerpcle-*-solaris*
5022 PowerPC Windows NT powerpcle-*-cygwin32
5023 PowerPC Netware powerpc-*-netware*
5024 Harris/CXUX m88k m88*-harris-cxux*
5025 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5026 ns32k-utek-sysv* ns32k-utek-*
5027 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5028 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5029 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5030 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5031 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5033 * Changes to command line processing
5035 The new `--args' feature can be used to specify command-line arguments
5036 for the inferior from gdb's command line.
5038 * Changes to key bindings
5040 There is a new `operate-and-get-next' function bound to `C-o'.
5042 *** Changes in GDB 5.1.1
5044 Fix compile problem on DJGPP.
5046 Fix a problem with floating-point registers on the i386 being
5049 Fix to stop GDB crashing on .debug_str debug info.
5051 Numerous documentation fixes.
5053 Numerous testsuite fixes.
5055 *** Changes in GDB 5.1:
5057 * New native configurations
5059 Alpha FreeBSD alpha*-*-freebsd*
5060 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5061 MIPS GNU/Linux mips*-*-linux*
5062 MIPS SGI Irix 6.x mips*-sgi-irix6*
5063 ia64 AIX ia64-*-aix*
5064 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5068 Motorola 68HC11 and 68HC12 m68hc11-elf
5070 UltraSparc running GNU/Linux sparc64-*-linux*
5072 * OBSOLETE configurations and files
5074 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5075 Harris/CXUX m88k m88*-harris-cxux*
5076 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5077 ns32k-utek-sysv* ns32k-utek-*
5078 TI TMS320C80 tic80-*-*
5080 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5081 PowerPC Solaris powerpcle-*-solaris*
5082 PowerPC Windows NT powerpcle-*-cygwin32
5083 PowerPC Netware powerpc-*-netware*
5084 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5085 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5086 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5087 Apple Macintosh (MPW) host N/A
5089 stuff.c (Program to stuff files into a specially prepared space in kdb)
5090 kdb-start.c (Main loop for the standalone kernel debugger)
5092 Configurations that have been declared obsolete in this release have
5093 been commented out. Unless there is activity to revive these
5094 configurations, the next release of GDB will have their sources
5095 permanently REMOVED.
5097 * REMOVED configurations and files
5099 Altos 3068 m68*-altos-*
5100 Convex c1-*-*, c2-*-*
5102 ARM RISCix arm-*-* (as host)
5106 * GDB has been converted to ISO C.
5108 GDB's source code has been converted to ISO C. In particular, the
5109 sources are fully protoized, and rely on standard headers being
5114 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5116 * The MI enabled by default.
5118 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5119 revised and enabled by default. Packages which use GDB as a debugging
5120 engine behind a UI or another front end are encouraged to switch to
5121 using the GDB/MI interface, instead of the old annotations interface
5122 which is now deprecated.
5124 * Support for debugging Pascal programs.
5126 GDB now includes support for debugging Pascal programs. The following
5127 main features are supported:
5129 - Pascal-specific data types such as sets;
5131 - automatic recognition of Pascal sources based on file-name
5134 - Pascal-style display of data types, variables, and functions;
5136 - a Pascal expression parser.
5138 However, some important features are not yet supported.
5140 - Pascal string operations are not supported at all;
5142 - there are some problems with boolean types;
5144 - Pascal type hexadecimal constants are not supported
5145 because they conflict with the internal variables format;
5147 - support for Pascal objects and classes is not full yet;
5149 - unlike Pascal, GDB is case-sensitive for symbol names.
5151 * Changes in completion.
5153 Commands such as `shell', `run' and `set args', which pass arguments
5154 to inferior programs, now complete on file names, similar to what
5155 users expect at the shell prompt.
5157 Commands which accept locations, such as `disassemble', `print',
5158 `breakpoint', `until', etc. now complete on filenames as well as
5159 program symbols. Thus, if you type "break foob TAB", and the source
5160 files linked into the programs include `foobar.c', that file name will
5161 be one of the candidates for completion. However, file names are not
5162 considered for completion after you typed a colon that delimits a file
5163 name from a name of a function in that file, as in "break foo.c:bar".
5165 `set demangle-style' completes on available demangling styles.
5167 * New platform-independent commands:
5169 It is now possible to define a post-hook for a command as well as a
5170 hook that runs before the command. For more details, see the
5171 documentation of `hookpost' in the GDB manual.
5173 * Changes in GNU/Linux native debugging.
5175 Support for debugging multi-threaded programs has been completely
5176 revised for all platforms except m68k and sparc. You can now debug as
5177 many threads as your system allows you to have.
5179 Attach/detach is supported for multi-threaded programs.
5181 Support for SSE registers was added for x86. This doesn't work for
5182 multi-threaded programs though.
5184 * Changes in MIPS configurations.
5186 Multi-arch support is enabled for all MIPS configurations.
5188 GDB can now be built as native debugger on SGI Irix 6.x systems for
5189 debugging n32 executables. (Debugging 64-bit executables is not yet
5192 * Unified support for hardware watchpoints in all x86 configurations.
5194 Most (if not all) native x86 configurations support hardware-assisted
5195 breakpoints and watchpoints in a unified manner. This support
5196 implements debug register sharing between watchpoints, which allows to
5197 put a virtually infinite number of watchpoints on the same address,
5198 and also supports watching regions up to 16 bytes with several debug
5201 The new maintenance command `maintenance show-debug-regs' toggles
5202 debugging print-outs in functions that insert, remove, and test
5203 watchpoints and hardware breakpoints.
5205 * Changes in the DJGPP native configuration.
5207 New command ``info dos sysinfo'' displays assorted information about
5208 the CPU, OS, memory, and DPMI server.
5210 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5211 display information about segment descriptors stored in GDT, LDT, and
5214 New commands ``info dos pde'' and ``info dos pte'' display entries
5215 from Page Directory and Page Tables (for now works with CWSDPMI only).
5216 New command ``info dos address-pte'' displays the Page Table entry for
5217 a given linear address.
5219 GDB can now pass command lines longer than 126 characters to the
5220 program being debugged (requires an update to the libdbg.a library
5221 which is part of the DJGPP development kit).
5223 DWARF2 debug info is now supported.
5225 It is now possible to `step' and `next' through calls to `longjmp'.
5227 * Changes in documentation.
5229 All GDB documentation was converted to GFDL, the GNU Free
5230 Documentation License.
5232 Tracepoints-related commands are now fully documented in the GDB
5235 TUI, the Text-mode User Interface, is now documented in the manual.
5237 Tracepoints-related commands are now fully documented in the GDB
5240 The "GDB Internals" manual now has an index. It also includes
5241 documentation of `ui_out' functions, GDB coding standards, x86
5242 hardware watchpoints, and memory region attributes.
5244 * GDB's version number moved to ``version.in''
5246 The Makefile variable VERSION has been replaced by the file
5247 ``version.in''. People creating GDB distributions should update the
5248 contents of this file.
5252 GUD support is now a standard part of the EMACS distribution.
5254 *** Changes in GDB 5.0:
5256 * Improved support for debugging FP programs on x86 targets
5258 Unified and much-improved support for debugging floating-point
5259 programs on all x86 targets. In particular, ``info float'' now
5260 displays the FP registers in the same format on all x86 targets, with
5261 greater level of detail.
5263 * Improvements and bugfixes in hardware-assisted watchpoints
5265 It is now possible to watch array elements, struct members, and
5266 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5267 on x86 targets no longer erroneously trigger when the address is
5270 * Improvements in the native DJGPP version of GDB
5272 The distribution now includes all the scripts and auxiliary files
5273 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5274 machines ``out of the box''.
5276 The DJGPP version can now debug programs that use signals. It is
5277 possible to catch signals that happened in the debuggee, deliver
5278 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5279 would kill the program being debugged.) Programs that hook hardware
5280 interrupts (keyboard, timer, etc.) can also be debugged.
5282 It is now possible to debug DJGPP programs that redirect their
5283 standard handles or switch them to raw (as opposed to cooked) mode, or
5284 even close them. The command ``run < foo > bar'' works as expected,
5285 and ``info terminal'' reports useful information about the debuggee's
5286 terminal, including raw/cooked mode, redirection, etc.
5288 The DJGPP version now uses termios functions for console I/O, which
5289 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5292 DOS-style file names with drive letters are now fully supported by
5295 It is now possible to debug DJGPP programs that switch their working
5296 directory. It is also possible to rerun the debuggee any number of
5297 times without restarting GDB; thus, you can use the same setup,
5298 breakpoints, etc. for many debugging sessions.
5300 * New native configurations
5302 ARM GNU/Linux arm*-*-linux*
5303 PowerPC GNU/Linux powerpc-*-linux*
5307 Motorola MCore mcore-*-*
5308 x86 VxWorks i[3456]86-*-vxworks*
5309 PowerPC VxWorks powerpc-*-vxworks*
5310 TI TMS320C80 tic80-*-*
5312 * OBSOLETE configurations
5314 Altos 3068 m68*-altos-*
5315 Convex c1-*-*, c2-*-*
5317 ARM RISCix arm-*-* (as host)
5320 Configurations that have been declared obsolete will be commented out,
5321 but the code will be left in place. If there is no activity to revive
5322 these configurations before the next release of GDB, the sources will
5323 be permanently REMOVED.
5325 * Gould support removed
5327 Support for the Gould PowerNode and NP1 has been removed.
5329 * New features for SVR4
5331 On SVR4 native platforms (such as Solaris), if you attach to a process
5332 without first loading a symbol file, GDB will now attempt to locate and
5333 load symbols from the running process's executable file.
5335 * Many C++ enhancements
5337 C++ support has been greatly improved. Overload resolution now works properly
5338 in almost all cases. RTTI support is on the way.
5340 * Remote targets can connect to a sub-program
5342 A popen(3) style serial-device has been added. This device starts a
5343 sub-process (such as a stand-alone simulator) and then communicates
5344 with that. The sub-program to run is specified using the syntax
5345 ``|<program> <args>'' vis:
5347 (gdb) set remotedebug 1
5348 (gdb) target extended-remote |mn10300-elf-sim program-args
5350 * MIPS 64 remote protocol
5352 A long standing bug in the mips64 remote protocol where by GDB
5353 expected certain 32 bit registers (ex SR) to be transfered as 32
5354 instead of 64 bits has been fixed.
5356 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5357 added to provide backward compatibility with older versions of GDB.
5359 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5361 The command ``set remotebinarydownload'' command has been replaced by
5362 ``set remote X-packet''. Other commands in ``set remote'' family
5363 include ``set remote P-packet''.
5365 * Breakpoint commands accept ranges.
5367 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5368 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5369 ``tracepoint passcount'' also accepts a range of tracepoints.
5371 * ``apropos'' command added.
5373 The ``apropos'' command searches through command names and
5374 documentation strings, printing out matches, making it much easier to
5375 try to find a command that does what you are looking for.
5379 A new machine oriented interface (MI) has been added to GDB. This
5380 interface is designed for debug environments running GDB as a separate
5381 process. This is part of the long term libGDB project. See the
5382 "GDB/MI" chapter of the GDB manual for further information. It can be
5383 enabled by configuring with:
5385 .../configure --enable-gdbmi
5387 *** Changes in GDB-4.18:
5389 * New native configurations
5391 HP-UX 10.20 hppa*-*-hpux10.20
5392 HP-UX 11.x hppa*-*-hpux11.0*
5393 M68K GNU/Linux m68*-*-linux*
5397 Fujitsu FR30 fr30-*-elf*
5398 Intel StrongARM strongarm-*-*
5399 Mitsubishi D30V d30v-*-*
5401 * OBSOLETE configurations
5403 Gould PowerNode, NP1 np1-*-*, pn-*-*
5405 Configurations that have been declared obsolete will be commented out,
5406 but the code will be left in place. If there is no activity to revive
5407 these configurations before the next release of GDB, the sources will
5408 be permanently REMOVED.
5412 As a compatibility experiment, GDB's source files buildsym.h and
5413 buildsym.c have been converted to pure standard C, no longer
5414 containing any K&R compatibility code. We believe that all systems in
5415 use today either come with a standard C compiler, or have a GCC port
5416 available. If this is not true, please report the affected
5417 configuration to bug-gdb@gnu.org immediately. See the README file for
5418 information about getting a standard C compiler if you don't have one
5423 GDB now uses readline 2.2.
5425 * set extension-language
5427 You can now control the mapping between filename extensions and source
5428 languages by using the `set extension-language' command. For instance,
5429 you can ask GDB to treat .c files as C++ by saying
5430 set extension-language .c c++
5431 The command `info extensions' lists all of the recognized extensions
5432 and their associated languages.
5434 * Setting processor type for PowerPC and RS/6000
5436 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5437 you can use the `set processor' command to specify what variant of the
5438 PowerPC family you are debugging. The command
5442 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5443 following PowerPC and RS6000 variants:
5445 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5446 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5448 403GC IBM PowerPC 403GC
5449 505 Motorola PowerPC 505
5450 860 Motorola PowerPC 860 or 850
5451 601 Motorola PowerPC 601
5452 602 Motorola PowerPC 602
5453 603 Motorola/IBM PowerPC 603 or 603e
5454 604 Motorola PowerPC 604 or 604e
5455 750 Motorola/IBM PowerPC 750 or 750
5457 At the moment, this command just tells GDB what to name the
5458 special-purpose processor registers. Since almost all the affected
5459 registers are inaccessible to user-level programs, this command is
5460 only useful for remote debugging in its present form.
5464 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5465 more extensive support for HP-UX. Added features include shared
5466 library support, kernel threads and hardware watchpoints for 11.00,
5467 support for HP's ANSI C and C++ compilers, and a compatibility mode
5468 for xdb and dbx commands.
5472 HP's donation includes the new concept of catchpoints, which is a
5473 generalization of the old catch command. On HP-UX, it is now possible
5474 to catch exec, fork, and vfork, as well as library loading.
5476 This means that the existing catch command has changed; its first
5477 argument now specifies the type of catch to be set up. See the
5478 output of "help catch" for a list of catchpoint types.
5480 * Debugging across forks
5482 On HP-UX, you can choose which process to debug when a fork() happens
5487 HP has donated a curses-based terminal user interface (TUI). To get
5488 it, build with --enable-tui. Although this can be enabled for any
5489 configuration, at present it only works for native HP debugging.
5491 * GDB remote protocol additions
5493 A new protocol packet 'X' that writes binary data is now available.
5494 Default behavior is to try 'X', then drop back to 'M' if the stub
5495 fails to respond. The settable variable `remotebinarydownload'
5496 allows explicit control over the use of 'X'.
5498 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5499 full 64-bit address. The command
5501 set remoteaddresssize 32
5503 can be used to revert to the old behaviour. For existing remote stubs
5504 the change should not be noticed, as the additional address information
5507 In order to assist in debugging stubs, you may use the maintenance
5508 command `packet' to send any text string to the stub. For instance,
5510 maint packet heythere
5512 sends the packet "$heythere#<checksum>". Note that it is very easy to
5513 disrupt a debugging session by sending the wrong packet at the wrong
5516 The compare-sections command allows you to compare section data on the
5517 target to what is in the executable file without uploading or
5518 downloading, by comparing CRC checksums.
5520 * Tracing can collect general expressions
5522 You may now collect general expressions at tracepoints. This requires
5523 further additions to the target-side stub; see tracepoint.c and
5524 doc/agentexpr.texi for further details.
5526 * mask-address variable for Mips
5528 For Mips targets, you may control the zeroing of the upper 32 bits of
5529 a 64-bit address by entering `set mask-address on'. This is mainly
5530 of interest to users of embedded R4xxx and R5xxx processors.
5532 * Higher serial baud rates
5534 GDB's serial code now allows you to specify baud rates 57600, 115200,
5535 230400, and 460800 baud. (Note that your host system may not be able
5536 to achieve all of these rates.)
5540 The i960 configuration now includes an initial implementation of a
5541 builtin simulator, contributed by Jim Wilson.
5544 *** Changes in GDB-4.17:
5546 * New native configurations
5548 Alpha GNU/Linux alpha*-*-linux*
5549 Unixware 2.x i[3456]86-unixware2*
5550 Irix 6.x mips*-sgi-irix6*
5551 PowerPC GNU/Linux powerpc-*-linux*
5552 PowerPC Solaris powerpcle-*-solaris*
5553 Sparc GNU/Linux sparc-*-linux*
5554 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5558 Argonaut Risc Chip (ARC) arc-*-*
5559 Hitachi H8/300S h8300*-*-*
5560 Matsushita MN10200 w/simulator mn10200-*-*
5561 Matsushita MN10300 w/simulator mn10300-*-*
5562 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5563 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5564 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5565 Mitsubishi D10V w/simulator d10v-*-*
5566 Mitsubishi M32R/D w/simulator m32r-*-elf*
5567 Tsqware Sparclet sparclet-*-*
5568 NEC V850 w/simulator v850-*-*
5570 * New debugging protocols
5572 ARM with RDI protocol arm*-*-*
5573 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5574 DDB and LSI variants of PMON protocol mips*-*-*
5575 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5576 PowerPC with SDS protocol powerpc{,le}-*-eabi
5577 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5581 All configurations can now understand and use the DWARF 2 debugging
5582 format. The choice is automatic, if the symbol file contains DWARF 2
5587 GDB now includes basic Java language support. This support is
5588 only useful with Java compilers that produce native machine code.
5590 * solib-absolute-prefix and solib-search-path
5592 For SunOS and SVR4 shared libraries, you may now set the prefix for
5593 loading absolute shared library symbol files, and the search path for
5594 locating non-absolute shared library symbol files.
5596 * Live range splitting
5598 GDB can now effectively debug code for which GCC has performed live
5599 range splitting as part of its optimization. See gdb/doc/LRS for
5600 more details on the expected format of the stabs information.
5604 GDB's support for the GNU Hurd, including thread debugging, has been
5605 updated to work with current versions of the Hurd.
5609 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5610 instruction set. ARM GDB automatically detects when Thumb
5611 instructions are in use, and adjusts disassembly and backtracing
5616 GDB's MIPS target configurations now handle the MIP16 16-bit
5621 GDB now includes support for overlays; if an executable has been
5622 linked such that multiple sections are based at the same address, GDB
5623 will decide which section to use for symbolic info. You can choose to
5624 control the decision manually, using overlay commands, or implement
5625 additional target-side support and use "overlay load-target" to bring
5626 in the overlay mapping. Do "help overlay" for more detail.
5630 The command "info symbol <address>" displays information about
5631 the symbol at the specified address.
5635 The standard remote protocol now includes an extension that allows
5636 asynchronous collection and display of trace data. This requires
5637 extensive support in the target-side debugging stub. Tracing mode
5638 includes a new interaction mode in GDB and new commands: see the
5639 file tracepoint.c for more details.
5643 Configurations for embedded MIPS now include a simulator contributed
5644 by Cygnus Solutions. The simulator supports the instruction sets
5645 of most MIPS variants.
5649 Sparc configurations may now include the ERC32 simulator contributed
5650 by the European Space Agency. The simulator is not built into
5651 Sparc targets by default; configure with --enable-sim to include it.
5655 For target configurations that may include multiple variants of a
5656 basic architecture (such as MIPS and SH), you may now set the
5657 architecture explicitly. "set arch" sets, "info arch" lists
5658 the possible architectures.
5660 *** Changes in GDB-4.16:
5662 * New native configurations
5664 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5665 M68K NetBSD m68k-*-netbsd*
5666 PowerPC AIX 4.x powerpc-*-aix*
5667 PowerPC MacOS powerpc-*-macos*
5668 PowerPC Windows NT powerpcle-*-cygwin32
5669 RS/6000 AIX 4.x rs6000-*-aix4*
5673 ARM with RDP protocol arm-*-*
5674 I960 with MON960 i960-*-coff
5675 MIPS VxWorks mips*-*-vxworks*
5676 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5677 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5679 Matra Sparclet sparclet-*-*
5683 The powerpc-eabi configuration now includes the PSIM simulator,
5684 contributed by Andrew Cagney, with assistance from Mike Meissner.
5685 PSIM is a very elaborate model of the PowerPC, including not only
5686 basic instruction set execution, but also details of execution unit
5687 performance and I/O hardware. See sim/ppc/README for more details.
5691 GDB now works with Solaris 2.5.
5693 * Windows 95/NT native
5695 GDB will now work as a native debugger on Windows 95 and Windows NT.
5696 To build it from source, you must use the "gnu-win32" environment,
5697 which uses a DLL to emulate enough of Unix to run the GNU tools.
5698 Further information, binaries, and sources are available at
5699 ftp.cygnus.com, under pub/gnu-win32.
5701 * dont-repeat command
5703 If a user-defined command includes the command `dont-repeat', then the
5704 command will not be repeated if the user just types return. This is
5705 useful if the command is time-consuming to run, so that accidental
5706 extra keystrokes don't run the same command many times.
5708 * Send break instead of ^C
5710 The standard remote protocol now includes an option to send a break
5711 rather than a ^C to the target in order to interrupt it. By default,
5712 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5714 * Remote protocol timeout
5716 The standard remote protocol includes a new variable `remotetimeout'
5717 that allows you to set the number of seconds before GDB gives up trying
5718 to read from the target. The default value is 2.
5720 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5722 By default GDB will automatically keep track of objects as they are
5723 loaded and unloaded by the dynamic linker. By using the command `set
5724 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5725 when shared library events occur, thus allowing you to set breakpoints
5726 in shared libraries which are explicitly loaded by the inferior.
5728 Note this feature does not work on hpux8. On hpux9 you must link
5729 /usr/lib/end.o into your program. This feature should work
5730 automatically on hpux10.
5732 * Irix 5.x hardware watchpoint support
5734 Irix 5 configurations now support the use of hardware watchpoints.
5736 * Mips protocol "SYN garbage limit"
5738 When debugging a Mips target using the `target mips' protocol, you
5739 may set the number of characters that GDB will ignore by setting
5740 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5741 every character. The default value is 1050.
5743 * Recording and replaying remote debug sessions
5745 If you set `remotelogfile' to the name of a file, gdb will write to it
5746 a recording of a remote debug session. This recording may then be
5747 replayed back to gdb using "gdbreplay". See gdbserver/README for
5748 details. This is useful when you have a problem with GDB while doing
5749 remote debugging; you can make a recording of the session and send it
5750 to someone else, who can then recreate the problem.
5752 * Speedups for remote debugging
5754 GDB includes speedups for downloading and stepping MIPS systems using
5755 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5756 and more efficient S-record downloading.
5758 * Memory use reductions and statistics collection
5760 GDB now uses less memory and reports statistics about memory usage.
5761 Try the `maint print statistics' command, for example.
5763 *** Changes in GDB-4.15:
5765 * Psymtabs for XCOFF
5767 The symbol reader for AIX GDB now uses partial symbol tables. This
5768 can greatly improve startup time, especially for large executables.
5770 * Remote targets use caching
5772 Remote targets now use a data cache to speed up communication with the
5773 remote side. The data cache could lead to incorrect results because
5774 it doesn't know about volatile variables, thus making it impossible to
5775 debug targets which use memory mapped I/O devices. `set remotecache
5776 off' turns the the data cache off.
5778 * Remote targets may have threads
5780 The standard remote protocol now includes support for multiple threads
5781 in the target system, using new protocol commands 'H' and 'T'. See
5782 gdb/remote.c for details.
5786 If GDB is configured with `--enable-netrom', then it will include
5787 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5788 acts as though it is a bank of ROM on the target board, but you can
5789 write into it over the network. GDB's support consists only of
5790 support for fast loading into the emulated ROM; to debug, you must use
5791 another protocol, such as standard remote protocol. The usual
5792 sequence is something like
5794 target nrom <netrom-hostname>
5796 target remote <netrom-hostname>:1235
5800 GDB now includes support for the Apple Macintosh, as a host only. It
5801 may be run as either an MPW tool or as a standalone application, and
5802 it can debug through the serial port. All the usual GDB commands are
5803 available, but to the target command, you must supply "serial" as the
5804 device type instead of "/dev/ttyXX". See mpw-README in the main
5805 directory for more information on how to build. The MPW configuration
5806 scripts */mpw-config.in support only a few targets, and only the
5807 mips-idt-ecoff target has been tested.
5811 GDB configuration now uses autoconf. This is not user-visible,
5812 but does simplify configuration and building.
5816 GDB now supports hpux10.
5818 *** Changes in GDB-4.14:
5820 * New native configurations
5822 x86 FreeBSD i[345]86-*-freebsd
5823 x86 NetBSD i[345]86-*-netbsd
5824 NS32k NetBSD ns32k-*-netbsd
5825 Sparc NetBSD sparc-*-netbsd
5829 A29K VxWorks a29k-*-vxworks
5830 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5831 CPU32 EST-300 emulator m68*-*-est*
5832 PowerPC ELF powerpc-*-elf
5835 * Alpha OSF/1 support for procfs
5837 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5838 possible to attach to running processes. As the mounting of the /proc
5839 filesystem is optional on the Alpha, GDB automatically determines
5840 the availability of /proc during startup. This can lead to problems
5841 if /proc is unmounted after GDB has been started.
5843 * Arguments to user-defined commands
5845 User commands may accept up to 10 arguments separated by whitespace.
5846 Arguments are accessed within the user command via $arg0..$arg9. A
5849 print $arg0 + $arg1 + $arg2
5851 To execute the command use:
5854 Defines the command "adder" which prints the sum of its three arguments.
5855 Note the arguments are text substitutions, so they may reference variables,
5856 use complex expressions, or even perform inferior function calls.
5858 * New `if' and `while' commands
5860 This makes it possible to write more sophisticated user-defined
5861 commands. Both commands take a single argument, which is the
5862 expression to evaluate, and must be followed by the commands to
5863 execute, one per line, if the expression is nonzero, the list being
5864 terminated by the word `end'. The `if' command list may include an
5865 `else' word, which causes the following commands to be executed only
5866 if the expression is zero.
5868 * Fortran source language mode
5870 GDB now includes partial support for Fortran 77. It will recognize
5871 Fortran programs and can evaluate a subset of Fortran expressions, but
5872 variables and functions may not be handled correctly. GDB will work
5873 with G77, but does not yet know much about symbols emitted by other
5876 * Better HPUX support
5878 Most debugging facilities now work on dynamic executables for HPPAs
5879 running hpux9 or later. You can attach to running dynamically linked
5880 processes, but by default the dynamic libraries will be read-only, so
5881 for instance you won't be able to put breakpoints in them. To change
5882 that behavior do the following before running the program:
5888 This will cause the libraries to be mapped private and read-write.
5889 To revert to the normal behavior, do this:
5895 You cannot set breakpoints or examine data in the library until after
5896 the library is loaded if the function/data symbols do not have
5899 GDB can now also read debug symbols produced by the HP C compiler on
5900 HPPAs (sorry, no C++, Fortran or 68k support).
5902 * Target byte order now dynamically selectable
5904 You can choose which byte order to use with a target system, via the
5905 commands "set endian big" and "set endian little", and you can see the
5906 current setting by using "show endian". You can also give the command
5907 "set endian auto", in which case GDB will use the byte order
5908 associated with the executable. Currently, only embedded MIPS
5909 configurations support dynamic selection of target byte order.
5911 * New DOS host serial code
5913 This version uses DPMI interrupts to handle buffered I/O, so you
5914 no longer need to run asynctsr when debugging boards connected to
5917 *** Changes in GDB-4.13:
5919 * New "complete" command
5921 This lists all the possible completions for the rest of the line, if it
5922 were to be given as a command itself. This is intended for use by emacs.
5924 * Trailing space optional in prompt
5926 "set prompt" no longer adds a space for you after the prompt you set. This
5927 allows you to set a prompt which ends in a space or one that does not.
5929 * Breakpoint hit counts
5931 "info break" now displays a count of the number of times the breakpoint
5932 has been hit. This is especially useful in conjunction with "ignore"; you
5933 can ignore a large number of breakpoint hits, look at the breakpoint info
5934 to see how many times the breakpoint was hit, then run again, ignoring one
5935 less than that number, and this will get you quickly to the last hit of
5938 * Ability to stop printing at NULL character
5940 "set print null-stop" will cause GDB to stop printing the characters of
5941 an array when the first NULL is encountered. This is useful when large
5942 arrays actually contain only short strings.
5944 * Shared library breakpoints
5946 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
5947 breakpoints in shared libraries before the executable is run.
5949 * Hardware watchpoints
5951 There is a new hardware breakpoint for the watch command for sparclite
5952 targets. See gdb/sparclite/hw_breakpoint.note.
5954 Hardware watchpoints are also now supported under GNU/Linux.
5958 Annotations have been added. These are for use with graphical interfaces,
5959 and are still experimental. Currently only gdba.el uses these.
5961 * Improved Irix 5 support
5963 GDB now works properly with Irix 5.2.
5965 * Improved HPPA support
5967 GDB now works properly with the latest GCC and GAS.
5969 * New native configurations
5971 Sequent PTX4 i[34]86-sequent-ptx4
5972 HPPA running OSF/1 hppa*-*-osf*
5973 Atari TT running SVR4 m68*-*-sysv4*
5974 RS/6000 LynxOS rs6000-*-lynxos*
5978 OS/9000 i[34]86-*-os9k
5979 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
5982 * Hitachi SH7000 and E7000-PC ICE support
5984 There is now support for communicating with the Hitachi E7000-PC ICE.
5985 This is available automatically when GDB is configured for the SH.
5989 As usual, a variety of small fixes and improvements, both generic
5990 and configuration-specific. See the ChangeLog for more detail.
5992 *** Changes in GDB-4.12:
5994 * Irix 5 is now supported
5998 GDB-4.12 on the HPPA has a number of changes which make it unable
5999 to debug the output from the currently released versions of GCC and
6000 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6001 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6002 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6005 *** Changes in GDB-4.11:
6007 * User visible changes:
6011 The "set remotedebug" option is now consistent between the mips remote
6012 target, remote targets using the gdb-specific protocol, UDI (AMD's
6013 debug protocol for the 29k) and the 88k bug monitor. It is now an
6014 integer specifying a debug level (normally 0 or 1, but 2 means more
6015 debugging info for the mips target).
6017 * DEC Alpha native support
6019 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6020 debug info, but GDB works fairly well with the DEC compiler and should
6021 work with a future GCC release. See the README file for a few
6022 Alpha-specific notes.
6024 * Preliminary thread implementation
6026 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6028 * LynxOS native and target support for 386
6030 This release has been hosted on LynxOS 2.2, and also can be configured
6031 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6034 * Improvements in C++ mangling/demangling.
6036 This release has much better g++ debugging, specifically in name
6037 mangling/demangling, virtual function calls, print virtual table,
6038 call methods, ...etc.
6040 *** Changes in GDB-4.10:
6042 * User visible changes:
6044 Remote debugging using the GDB-specific (`target remote') protocol now
6045 supports the `load' command. This is only useful if you have some
6046 other way of getting the stub to the target system, and you can put it
6047 somewhere in memory where it won't get clobbered by the download.
6049 Filename completion now works.
6051 When run under emacs mode, the "info line" command now causes the
6052 arrow to point to the line specified. Also, "info line" prints
6053 addresses in symbolic form (as well as hex).
6055 All vxworks based targets now support a user settable option, called
6056 vxworks-timeout. This option represents the number of seconds gdb
6057 should wait for responses to rpc's. You might want to use this if
6058 your vxworks target is, perhaps, a slow software simulator or happens
6059 to be on the far side of a thin network line.
6063 This release contains support for using a DEC alpha as a GDB host for
6064 cross debugging. Native alpha debugging is not supported yet.
6067 *** Changes in GDB-4.9:
6071 This is the first GDB release which is accompanied by a matching testsuite.
6072 The testsuite requires installation of dejagnu, which should be available
6073 via ftp from most sites that carry GNU software.
6077 'Cfront' style demangling has had its name changed to 'ARM' style, to
6078 emphasize that it was written from the specifications in the C++ Annotated
6079 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6080 disclaimers, it still generated too much confusion with users attempting to
6081 use gdb with AT&T cfront.
6085 GDB now uses a standard remote interface to a simulator library.
6086 So far, the library contains simulators for the Zilog Z8001/2, the
6087 Hitachi H8/300, H8/500 and Super-H.
6089 * New targets supported
6091 H8/300 simulator h8300-hitachi-hms or h8300hms
6092 H8/500 simulator h8500-hitachi-hms or h8500hms
6093 SH simulator sh-hitachi-hms or sh
6094 Z8000 simulator z8k-zilog-none or z8ksim
6095 IDT MIPS board over serial line mips-idt-ecoff
6097 Cross-debugging to GO32 targets is supported. It requires a custom
6098 version of the i386-stub.c module which is integrated with the
6099 GO32 memory extender.
6101 * New remote protocols
6103 MIPS remote debugging protocol.
6105 * New source languages supported
6107 This version includes preliminary support for Chill, a Pascal like language
6108 used by telecommunications companies. Chill support is also being integrated
6109 into the GNU compiler, but we don't know when it will be publically available.
6112 *** Changes in GDB-4.8:
6114 * HP Precision Architecture supported
6116 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6117 version of this support was available as a set of patches from the
6118 University of Utah. GDB does not support debugging of programs
6119 compiled with the HP compiler, because HP will not document their file
6120 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6121 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6123 Many problems in the preliminary version have been fixed.
6125 * Faster and better demangling
6127 We have improved template demangling and fixed numerous bugs in the GNU style
6128 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6129 character types (wchar_t) are now supported. Demangling of each symbol is now
6130 only done once, and is cached when the symbol table for a file is read in.
6131 This results in a small increase in memory usage for C programs, a moderate
6132 increase in memory usage for C++ programs, and a fantastic speedup in
6135 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6136 from the specifications in the Annotated Reference Manual, which AT&T's
6137 compiler does not actually implement.
6139 * G++ multiple inheritance compiler problem
6141 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6142 inheritance lattices was reworked to properly discover ambiguities. We
6143 recently found an example which causes this new algorithm to fail in a
6144 very subtle way, producing bad debug information for those classes.
6145 The file 'gcc.patch' (in this directory) can be applied to gcc to
6146 circumvent the problem. A future GCC release will contain a complete
6149 The previous G++ debug info problem (mentioned below for the gdb-4.7
6150 release) is fixed in gcc version 2.3.2.
6152 * Improved configure script
6154 The `configure' script will now attempt to guess your system type if
6155 you don't supply a host system type. The old scheme of supplying a
6156 host system triplet is preferable over using this. All the magic is
6157 done in the new `config.guess' script. Examine it for details.
6159 We have also brought our configure script much more in line with the FSF's
6160 version. It now supports the --with-xxx options. In particular,
6161 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6162 The resulting GDB will not be able to read arbitrary object file formats --
6163 only the format ``expected'' to be used on the configured target system.
6164 We hope to make this the default in a future release.
6166 * Documentation improvements
6168 There's new internal documentation on how to modify GDB, and how to
6169 produce clean changes to the code. We implore people to read it
6170 before submitting changes.
6172 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6173 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6174 `info' files are also provided. To build `info' files from scratch,
6175 you will need the latest `makeinfo' release, which will be available in
6176 a future texinfo-X.Y release.
6178 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6179 We're not sure exactly which versions have this problem, but it has
6180 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6181 or better. If that isn't possible, there is a patch in
6182 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6183 around this problem.
6187 GDB now supports array constants that can be used in expressions typed in by
6188 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6189 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6192 The new directory `gdb/sparclite' contains a program that demonstrates
6193 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6195 * New native hosts supported
6197 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6198 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6200 * New targets supported
6202 AMD 29k family via UDI a29k-amd-udi or udi29k
6204 * New file formats supported
6206 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6207 HPUX core files, and SCO 3.2v2 core files.
6211 Attaching to processes now works again; thanks for the many bug reports.
6213 We have also stomped on a bunch of core dumps caused by
6214 printf_filtered("%s") problems.
6216 We eliminated a copyright problem on the rpc and ptrace header files
6217 for VxWorks, which was discovered at the last minute during the 4.7
6218 release. You should now be able to build a VxWorks GDB.
6220 You can now interrupt gdb while an attached process is running. This
6221 will cause the attached process to stop, and give control back to GDB.
6223 We fixed problems caused by using too many file descriptors
6224 for reading symbols from object files and libraries. This was
6225 especially a problem for programs that used many (~100) shared
6228 The `step' command now only enters a subroutine if there is line number
6229 information for the subroutine. Otherwise it acts like the `next'
6230 command. Previously, `step' would enter subroutines if there was
6231 any debugging information about the routine. This avoids problems
6232 when using `cc -g1' on MIPS machines.
6234 * Internal improvements
6236 GDB's internal interfaces have been improved to make it easier to support
6237 debugging of multiple languages in the future.
6239 GDB now uses a common structure for symbol information internally.
6240 Minimal symbols (derived from linkage symbols in object files), partial
6241 symbols (from a quick scan of debug information), and full symbols
6242 contain a common subset of information, making it easier to write
6243 shared code that handles any of them.
6245 * New command line options
6247 We now accept --silent as an alias for --quiet.
6251 The memory-mapped-malloc library is now licensed under the GNU Library
6252 General Public License.
6254 *** Changes in GDB-4.7:
6256 * Host/native/target split
6258 GDB has had some major internal surgery to untangle the support for
6259 hosts and remote targets. Now, when you configure GDB for a remote
6260 target, it will no longer load in all of the support for debugging
6261 local programs on the host. When fully completed and tested, this will
6262 ensure that arbitrary host/target combinations are possible.
6264 The primary conceptual shift is to separate the non-portable code in
6265 GDB into three categories. Host specific code is required any time GDB
6266 is compiled on that host, regardless of the target. Target specific
6267 code relates to the peculiarities of the target, but can be compiled on
6268 any host. Native specific code is everything else: it can only be
6269 built when the host and target are the same system. Child process
6270 handling and core file support are two common `native' examples.
6272 GDB's use of /proc for controlling Unix child processes is now cleaner.
6273 It has been split out into a single module under the `target_ops' vector,
6274 plus two native-dependent functions for each system that uses /proc.
6276 * New hosts supported
6278 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6279 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6280 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6282 * New targets supported
6284 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6285 68030 and CPU32 m68030-*-*, m68332-*-*
6287 * New native hosts supported
6289 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6290 (386bsd is not well tested yet)
6291 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6293 * New file formats supported
6295 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6296 supports reading of `a.out.adobe' object files, which are an a.out
6297 format extended with minimal information about multiple sections.
6301 `show copying' is the same as the old `info copying'.
6302 `show warranty' is the same as `info warrantee'.
6303 These were renamed for consistency. The old commands continue to work.
6305 `info handle' is a new alias for `info signals'.
6307 You can now define pre-command hooks, which attach arbitrary command
6308 scripts to any command. The commands in the hook will be executed
6309 prior to the user's command. You can also create a hook which will be
6310 executed whenever the program stops. See gdb.texinfo.
6314 We now deal with Cfront style name mangling, and can even extract type
6315 info from mangled symbols. GDB can automatically figure out which
6316 symbol mangling style your C++ compiler uses.
6318 Calling of methods and virtual functions has been improved as well.
6322 The crash that occured when debugging Sun Ansi-C compiled binaries is
6323 fixed. This was due to mishandling of the extra N_SO stabs output
6326 We also finally got Ultrix 4.2 running in house, and fixed core file
6327 support, with help from a dozen people on the net.
6329 John M. Farrell discovered that the reason that single-stepping was so
6330 slow on all of the Mips based platforms (primarily SGI and DEC) was
6331 that we were trying to demangle and lookup a symbol used for internal
6332 purposes on every instruction that was being stepped through. Changing
6333 the name of that symbol so that it couldn't be mistaken for a C++
6334 mangled symbol sped things up a great deal.
6336 Rich Pixley sped up symbol lookups in general by getting much smarter
6337 about when C++ symbol mangling is necessary. This should make symbol
6338 completion (TAB on the command line) much faster. It's not as fast as
6339 we'd like, but it's significantly faster than gdb-4.6.
6343 A new user controllable variable 'call_scratch_address' can
6344 specify the location of a scratch area to be used when GDB
6345 calls a function in the target. This is necessary because the
6346 usual method of putting the scratch area on the stack does not work
6347 in systems that have separate instruction and data spaces.
6349 We integrated changes to support the 29k UDI (Universal Debugger
6350 Interface), but discovered at the last minute that we didn't have all
6351 of the appropriate copyright paperwork. We are working with AMD to
6352 resolve this, and hope to have it available soon.
6356 We have sped up the remote serial line protocol, especially for targets
6357 with lots of registers. It now supports a new `expedited status' ('T')
6358 message which can be used in place of the existing 'S' status message.
6359 This allows the remote stub to send only the registers that GDB
6360 needs to make a quick decision about single-stepping or conditional
6361 breakpoints, eliminating the need to fetch the entire register set for
6362 each instruction being stepped through.
6364 The GDB remote serial protocol now implements a write-through cache for
6365 registers, only re-reading the registers if the target has run.
6367 There is also a new remote serial stub for SPARC processors. You can
6368 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6369 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6370 processor with a serial port.
6374 Configure.in files have become much easier to read and modify. A new
6375 `table driven' format makes it more obvious what configurations are
6376 supported, and what files each one uses.
6380 There is a new opcodes library which will eventually contain all of the
6381 disassembly routines and opcode tables. At present, it only contains
6382 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6383 disassembler (binutils/objdump) to share these routines.
6385 The libiberty library is now copylefted under the GNU Library General
6386 Public License. This allows more liberal use, and was done so libg++
6387 can use it. This makes no difference to GDB, since the Library License
6388 grants all the rights from the General Public License.
6392 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6393 reference to the stabs symbol info used by the debugger. It is (as far
6394 as we know) the only published document on this fascinating topic. We
6395 encourage you to read it, compare it to the stabs information on your
6396 system, and send improvements on the document in general (to
6397 bug-gdb@prep.ai.mit.edu).
6399 And, of course, many bugs have been fixed.
6402 *** Changes in GDB-4.6:
6404 * Better support for C++ function names
6406 GDB now accepts as input the "demangled form" of C++ overloaded function
6407 names and member function names, and can do command completion on such names
6408 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6409 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6410 Make use of command completion, it is your friend.
6412 GDB also now accepts a variety of C++ mangled symbol formats. They are
6413 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6414 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6415 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6416 for the list of formats.
6418 * G++ symbol mangling problem
6420 Recent versions of gcc have a bug in how they emit debugging information for
6421 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6422 directory) can be applied to gcc to fix the problem. Alternatively, if you
6423 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6424 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6425 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6428 * New 'maintenance' command
6430 All of the commands related to hacking GDB internals have been moved out of
6431 the main command set, and now live behind the 'maintenance' command. This
6432 can also be abbreviated as 'mt'. The following changes were made:
6434 dump-me -> maintenance dump-me
6435 info all-breakpoints -> maintenance info breakpoints
6436 printmsyms -> maintenance print msyms
6437 printobjfiles -> maintenance print objfiles
6438 printpsyms -> maintenance print psymbols
6439 printsyms -> maintenance print symbols
6441 The following commands are new:
6443 maintenance demangle Call internal GDB demangler routine to
6444 demangle a C++ link name and prints the result.
6445 maintenance print type Print a type chain for a given symbol
6447 * Change to .gdbinit file processing
6449 We now read the $HOME/.gdbinit file before processing the argv arguments
6450 (e.g. reading symbol files or core files). This allows global parameters to
6451 be set, which will apply during the symbol reading. The ./.gdbinit is still
6452 read after argv processing.
6454 * New hosts supported
6456 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6458 GNU/Linux support i386-unknown-linux or linux
6460 We are also including code to support the HP/PA running BSD and HPUX. This
6461 is almost guaranteed not to work, as we didn't have time to test or build it
6462 for this release. We are including it so that the more adventurous (or
6463 masochistic) of you can play with it. We also had major problems with the
6464 fact that the compiler that we got from HP doesn't support the -g option.
6467 * New targets supported
6469 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6471 * More smarts about finding #include files
6473 GDB now remembers the compilation directory for all include files, and for
6474 all files from which C is generated (like yacc and lex sources). This
6475 greatly improves GDB's ability to find yacc/lex sources, and include files,
6476 especially if you are debugging your program from a directory different from
6477 the one that contains your sources.
6479 We also fixed a bug which caused difficulty with listing and setting
6480 breakpoints in include files which contain C code. (In the past, you had to
6481 try twice in order to list an include file that you hadn't looked at before.)
6483 * Interesting infernals change
6485 GDB now deals with arbitrary numbers of sections, where the symbols for each
6486 section must be relocated relative to that section's landing place in the
6487 target's address space. This work was needed to support ELF with embedded
6488 stabs used by Solaris-2.0.
6490 * Bug fixes (of course!)
6492 There have been loads of fixes for the following things:
6493 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6494 i960, stabs, DOS(GO32), procfs, etc...
6496 See the ChangeLog for details.
6498 *** Changes in GDB-4.5:
6500 * New machines supported (host and target)
6502 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6504 SGI Irix-4.x mips-sgi-irix4 or iris4
6506 * New malloc package
6508 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6509 Mmalloc is capable of handling mutiple heaps of memory. It is also
6510 capable of saving a heap to a file, and then mapping it back in later.
6511 This can be used to greatly speedup the startup of GDB by using a
6512 pre-parsed symbol table which lives in a mmalloc managed heap. For
6513 more details, please read mmalloc/mmalloc.texi.
6517 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6518 'help info proc' for details.
6520 * MIPS ecoff symbol table format
6522 The code that reads MIPS symbol table format is now supported on all hosts.
6523 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6526 * File name changes for MS-DOS
6528 Many files in the config directories have been renamed to make it easier to
6529 support GDB on MS-DOSe systems (which have very restrictive file name
6530 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6531 environment) is close to working but has some remaining problems. Note
6532 that debugging of DOS programs is not supported, due to limitations
6533 in the ``operating system'', but it can be used to host cross-debugging.
6535 * Cross byte order fixes
6537 Many fixes have been made to support cross debugging of Sparc and MIPS
6538 targets from hosts whose byte order differs.
6540 * New -mapped and -readnow options
6542 If memory-mapped files are available on your system through the 'mmap'
6543 system call, you can use the -mapped option on the `file' or
6544 `symbol-file' commands to cause GDB to write the symbols from your
6545 program into a reusable file. If the program you are debugging is
6546 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6547 Future GDB debugging sessions will notice the presence of this file,
6548 and will quickly map in symbol information from it, rather than reading
6549 the symbol table from the executable program. Using the '-mapped'
6550 option in a GDB `file' or `symbol-file' command has the same effect as
6551 starting GDB with the '-mapped' command-line option.
6553 You can cause GDB to read the entire symbol table immediately by using
6554 the '-readnow' option with any of the commands that load symbol table
6555 information (or on the GDB command line). This makes the command
6556 slower, but makes future operations faster.
6558 The -mapped and -readnow options are typically combined in order to
6559 build a `fred.syms' file that contains complete symbol information.
6560 A simple GDB invocation to do nothing but build a `.syms' file for future
6563 gdb -batch -nx -mapped -readnow programname
6565 The `.syms' file is specific to the host machine on which GDB is run.
6566 It holds an exact image of GDB's internal symbol table. It cannot be
6567 shared across multiple host platforms.
6569 * longjmp() handling
6571 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6572 siglongjmp() without losing control. This feature has not yet been ported to
6573 all systems. It currently works on many 386 platforms, all MIPS-based
6574 platforms (SGI, DECstation, etc), and Sun3/4.
6578 Preliminary work has been put in to support the new Solaris OS from Sun. At
6579 this time, it can control and debug processes, but it is not capable of
6584 As always, many many bug fixes. The major areas were with g++, and mipsread.
6585 People using the MIPS-based platforms should experience fewer mysterious
6586 crashes and trashed symbol tables.
6588 *** Changes in GDB-4.4:
6590 * New machines supported (host and target)
6592 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6594 BSD Reno on Vax vax-dec-bsd
6595 Ultrix on Vax vax-dec-ultrix
6597 * New machines supported (target)
6599 AMD 29000 embedded, using EBMON a29k-none-none
6603 GDB continues to improve its handling of C++. `References' work better.
6604 The demangler has also been improved, and now deals with symbols mangled as
6605 per the Annotated C++ Reference Guide.
6607 GDB also now handles `stabs' symbol information embedded in MIPS
6608 `ecoff' symbol tables. Since the ecoff format was not easily
6609 extensible to handle new languages such as C++, this appeared to be a
6610 good way to put C++ debugging info into MIPS binaries. This option
6611 will be supported in the GNU C compiler, version 2, when it is
6614 * New features for SVR4
6616 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6617 shared libraries. Debugging dynamically linked programs should present
6618 only minor differences from debugging statically linked programs.
6620 The `info proc' command will print out information about any process
6621 on an SVR4 system (including the one you are debugging). At the moment,
6622 it prints the address mappings of the process.
6624 If you bring up GDB on another SVR4 system, please send mail to
6625 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6627 * Better dynamic linking support in SunOS
6629 Reading symbols from shared libraries which contain debugging symbols
6630 now works properly. However, there remain issues such as automatic
6631 skipping of `transfer vector' code during function calls, which
6632 make it harder to debug code in a shared library, than to debug the
6633 same code linked statically.
6637 GDB is now using the latest `getopt' routines from the FSF. This
6638 version accepts the -- prefix for options with long names. GDB will
6639 continue to accept the old forms (-option and +option) as well.
6640 Various single letter abbreviations for options have been explicity
6641 added to the option table so that they won't get overshadowed in the
6642 future by other options that begin with the same letter.
6646 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6647 Many assorted bugs have been handled. Many more remain to be handled.
6648 See the various ChangeLog files (primarily in gdb and bfd) for details.
6651 *** Changes in GDB-4.3:
6653 * New machines supported (host and target)
6655 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6656 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6657 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6659 * Almost SCO Unix support
6661 We had hoped to support:
6662 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6663 (except for core file support), but we discovered very late in the release
6664 that it has problems with process groups that render gdb unusable. Sorry
6665 about that. I encourage people to fix it and post the fixes.
6667 * Preliminary ELF and DWARF support
6669 GDB can read ELF object files on System V Release 4, and can handle
6670 debugging records for C, in DWARF format, in ELF files. This support
6671 is preliminary. If you bring up GDB on another SVR4 system, please
6672 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6677 GDB now uses the latest `readline' library. One user-visible change
6678 is that two tabs will list possible command completions, which previously
6679 required typing M-? (meta-question mark, or ESC ?).
6683 The `stepi' bug that many of you noticed has been squashed.
6684 Many bugs in C++ have been handled. Many more remain to be handled.
6685 See the various ChangeLog files (primarily in gdb and bfd) for details.
6687 * State of the MIPS world (in case you wondered):
6689 GDB can understand the symbol tables emitted by the compilers
6690 supplied by most vendors of MIPS-based machines, including DEC. These
6691 symbol tables are in a format that essentially nobody else uses.
6693 Some versions of gcc come with an assembler post-processor called
6694 mips-tfile. This program is required if you want to do source-level
6695 debugging of gcc-compiled programs. I believe FSF does not ship
6696 mips-tfile with gcc version 1, but it will eventually come with gcc
6699 Debugging of g++ output remains a problem. g++ version 1.xx does not
6700 really support it at all. (If you're lucky, you should be able to get
6701 line numbers and stack traces to work, but no parameters or local
6702 variables.) With some work it should be possible to improve the
6705 When gcc version 2 is released, you will have somewhat better luck.
6706 However, even then you will get confusing results for inheritance and
6709 We will eventually provide full debugging of g++ output on
6710 DECstations. This will probably involve some kind of stabs-in-ecoff
6711 encapulation, but the details have not been worked out yet.
6714 *** Changes in GDB-4.2:
6716 * Improved configuration
6718 Only one copy of `configure' exists now, and it is not self-modifying.
6719 Porting BFD is simpler.
6723 The `step' and `next' commands now only stop at the first instruction
6724 of a source line. This prevents the multiple stops that used to occur
6725 in switch statements, for-loops, etc. `Step' continues to stop if a
6726 function that has debugging information is called within the line.
6730 Lots of small bugs fixed. More remain.
6732 * New host supported (not target)
6734 Intel 386 PC clone running Mach i386-none-mach
6737 *** Changes in GDB-4.1:
6739 * Multiple source language support
6741 GDB now has internal scaffolding to handle several source languages.
6742 It determines the type of each source file from its filename extension,
6743 and will switch expression parsing and number formatting to match the
6744 language of the function in the currently selected stack frame.
6745 You can also specifically set the language to be used, with
6746 `set language c' or `set language modula-2'.
6750 GDB now has preliminary support for the GNU Modula-2 compiler,
6751 currently under development at the State University of New York at
6752 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6753 continue through the fall of 1991 and into 1992.
6755 Other Modula-2 compilers are currently not supported, and attempting to
6756 debug programs compiled with them will likely result in an error as the
6757 symbol table is read. Feel free to work on it, though!
6759 There are hooks in GDB for strict type checking and range checking,
6760 in the `Modula-2 philosophy', but they do not currently work.
6764 GDB can now write to executable and core files (e.g. patch
6765 a variable's value). You must turn this switch on, specify
6766 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6767 by assigning a new value to a variable. Modifications take
6770 * Automatic SunOS shared library reading
6772 When you run your program, GDB automatically determines where its
6773 shared libraries (if any) have been loaded, and reads their symbols.
6774 The `share' command is no longer needed. This also works when
6775 examining core files.
6779 You can specify the number of lines that the `list' command shows.
6782 * New machines supported (host and target)
6784 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6785 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6786 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6788 * New hosts supported (not targets)
6790 IBM RT/PC: romp-ibm-aix or rtpc
6792 * New targets supported (not hosts)
6794 AMD 29000 embedded with COFF a29k-none-coff
6795 AMD 29000 embedded with a.out a29k-none-aout
6796 Ultracomputer remote kernel debug a29k-nyu-kern
6798 * New remote interfaces
6804 *** Changes in GDB-4.0:
6808 Wide output is wrapped at good places to make the output more readable.
6810 Gdb now supports cross-debugging from a host machine of one type to a
6811 target machine of another type. Communication with the target system
6812 is over serial lines. The ``target'' command handles connecting to the
6813 remote system; the ``load'' command will download a program into the
6814 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6815 also supports debugging of realtime processes running under VxWorks,
6816 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6817 stub on the target system.
6819 New CPUs supported include the AMD 29000 and Intel 960.
6821 GDB now reads object files and symbol tables via a ``binary file''
6822 library, which allows a single copy of GDB to debug programs of multiple
6823 object file types such as a.out and coff.
6825 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6826 refcard.dvi and refcard.ps are available to format it).
6829 * Control-Variable user interface simplified
6831 All variables that control the operation of the debugger can be set
6832 by the ``set'' command, and displayed by the ``show'' command.
6834 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6835 ``Show prompt'' produces the response:
6836 Gdb's prompt is new-gdb=>.
6838 What follows are the NEW set commands. The command ``help set'' will
6839 print a complete list of old and new set commands. ``help set FOO''
6840 will give a longer description of the variable FOO. ``show'' will show
6841 all of the variable descriptions and their current settings.
6843 confirm on/off: Enables warning questions for operations that are
6844 hard to recover from, e.g. rerunning the program while
6845 it is already running. Default is ON.
6847 editing on/off: Enables EMACS style command line editing
6848 of input. Previous lines can be recalled with
6849 control-P, the current line can be edited with control-B,
6850 you can search for commands with control-R, etc.
6853 history filename NAME: NAME is where the gdb command history
6854 will be stored. The default is .gdb_history,
6855 or the value of the environment variable
6858 history size N: The size, in commands, of the command history. The
6859 default is 256, or the value of the environment variable
6862 history save on/off: If this value is set to ON, the history file will
6863 be saved after exiting gdb. If set to OFF, the
6864 file will not be saved. The default is OFF.
6866 history expansion on/off: If this value is set to ON, then csh-like
6867 history expansion will be performed on
6868 command line input. The default is OFF.
6870 radix N: Sets the default radix for input and output. It can be set
6871 to 8, 10, or 16. Note that the argument to "radix" is interpreted
6872 in the current radix, so "set radix 10" is always a no-op.
6874 height N: This integer value is the number of lines on a page. Default
6875 is 24, the current `stty rows'' setting, or the ``li#''
6876 setting from the termcap entry matching the environment
6879 width N: This integer value is the number of characters on a line.
6880 Default is 80, the current `stty cols'' setting, or the ``co#''
6881 setting from the termcap entry matching the environment
6884 Note: ``set screensize'' is obsolete. Use ``set height'' and
6885 ``set width'' instead.
6887 print address on/off: Print memory addresses in various command displays,
6888 such as stack traces and structure values. Gdb looks
6889 more ``symbolic'' if you turn this off; it looks more
6890 ``machine level'' with it on. Default is ON.
6892 print array on/off: Prettyprint arrays. New convenient format! Default
6895 print demangle on/off: Print C++ symbols in "source" form if on,
6898 print asm-demangle on/off: Same, for assembler level printouts
6901 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
6904 * Support for Epoch Environment.
6906 The epoch environment is a version of Emacs v18 with windowing. One
6907 new command, ``inspect'', is identical to ``print'', except that if you
6908 are running in the epoch environment, the value is printed in its own
6912 * Support for Shared Libraries
6914 GDB can now debug programs and core files that use SunOS shared libraries.
6915 Symbols from a shared library cannot be referenced
6916 before the shared library has been linked with the program (this
6917 happens after you type ``run'' and before the function main() is entered).
6918 At any time after this linking (including when examining core files
6919 from dynamically linked programs), gdb reads the symbols from each
6920 shared library when you type the ``sharedlibrary'' command.
6921 It can be abbreviated ``share''.
6923 sharedlibrary REGEXP: Load shared object library symbols for files
6924 matching a unix regular expression. No argument
6925 indicates to load symbols for all shared libraries.
6927 info sharedlibrary: Status of loaded shared libraries.
6932 A watchpoint stops execution of a program whenever the value of an
6933 expression changes. Checking for this slows down execution
6934 tremendously whenever you are in the scope of the expression, but is
6935 quite useful for catching tough ``bit-spreader'' or pointer misuse
6936 problems. Some machines such as the 386 have hardware for doing this
6937 more quickly, and future versions of gdb will use this hardware.
6939 watch EXP: Set a watchpoint (breakpoint) for an expression.
6941 info watchpoints: Information about your watchpoints.
6943 delete N: Deletes watchpoint number N (same as breakpoints).
6944 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
6945 enable N: Re-enables watchpoint number N (same as breakpoints).
6948 * C++ multiple inheritance
6950 When used with a GCC version 2 compiler, GDB supports multiple inheritance
6953 * C++ exception handling
6955 Gdb now supports limited C++ exception handling. Besides the existing
6956 ability to breakpoint on an exception handler, gdb can breakpoint on
6957 the raising of an exception (before the stack is peeled back to the
6960 catch FOO: If there is a FOO exception handler in the dynamic scope,
6961 set a breakpoint to catch exceptions which may be raised there.
6962 Multiple exceptions (``catch foo bar baz'') may be caught.
6964 info catch: Lists all exceptions which may be caught in the
6965 current stack frame.
6968 * Minor command changes
6970 The command ``call func (arg, arg, ...)'' now acts like the print
6971 command, except it does not print or save a value if the function's result
6972 is void. This is similar to dbx usage.
6974 The ``up'' and ``down'' commands now always print the frame they end up
6975 at; ``up-silently'' and `down-silently'' can be used in scripts to change
6976 frames without printing.
6978 * New directory command
6980 'dir' now adds directories to the FRONT of the source search path.
6981 The path starts off empty. Source files that contain debug information
6982 about the directory in which they were compiled can be found even
6983 with an empty path; Sun CC and GCC include this information. If GDB can't
6984 find your source file in the current directory, type "dir .".
6986 * Configuring GDB for compilation
6988 For normal use, type ``./configure host''. See README or gdb.texinfo
6991 GDB now handles cross debugging. If you are remotely debugging between
6992 two different machines, type ``./configure host -target=targ''.
6993 Host is the machine where GDB will run; targ is the machine
6994 where the program that you are debugging will run.