1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
6 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
7 can be passed using the '[ADDRESS]:PORT' notation, or the regular
10 * DWARF index cache: GDB can now automatically save indices of DWARF
11 symbols on disk to speed up further loading of the same binaries.
15 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
16 Apply a command to some frames.
17 FLAG arguments allow to control what output to produce and how to handle
18 errors raised when applying COMMAND to a frame.
21 Apply a command to all threads (ignoring errors and empty output).
22 Shortcut for 'thread apply all -s COMMAND'.
25 Apply a command to all frames (ignoring errors and empty output).
26 Shortcut for 'frame apply all -s COMMAND'.
29 Apply a command to all frames of all threads (ignoring errors and empty
31 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
33 maint set dwarf unwinders (on|off)
34 maint show dwarf unwinders
35 Control whether DWARF unwinders can be used.
39 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
40 The 'thread apply' command accepts new FLAG arguments.
41 FLAG arguments allow to control what output to produce and how to handle
42 errors raised when applying COMMAND to a thread.
46 ** The '-data-disassemble' MI command now accepts an '-a' option to
47 disassemble the whole function surrounding the given program
48 counter value or function name. Support for this feature can be
49 verified by using the "-list-features" command, which should
50 contain "data-disassemble-a-option".
52 ** Command responses and notifications that include a frame now include
53 the frame's architecture in a new "arch" attribute.
55 * New native configurations
57 GNU/Linux/RISC-V riscv*-*-linux*
61 GNU/Linux/RISC-V riscv*-*-linux*
63 CSKY GNU/LINUX csky*-*-linux
65 *** Changes in GDB 8.2
67 * The 'set disassembler-options' command now supports specifying options
70 * The 'symbol-file' command now accepts an '-o' option to add a relative
71 offset to all sections.
73 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
74 a relative offset to all sections, but it allows to override the load
75 address of individual sections using '-s'.
77 * The 'add-symbol-file' command no longer requires the second argument
78 (address of the text section).
80 * The endianness used with the 'set endian auto' mode in the absence of
81 an executable selected for debugging is now the last endianness chosen
82 either by one of the 'set endian big' and 'set endian little' commands
83 or by inferring from the last executable used, rather than the startup
86 * The pager now allows a "c" response, meaning to disable the pager
87 for the rest of the current command.
89 * The commands 'info variables/functions/types' now show the source line
90 numbers of symbol definitions when available.
92 * 'info proc' now works on running processes on FreeBSD systems and core
93 files created on FreeBSD systems.
95 * C expressions can now use _Alignof, and C++ expressions can now use
98 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
99 the vector length while the process is running.
105 Control display of debugging info regarding the FreeBSD native target.
107 set|show varsize-limit
108 This new setting allows the user to control the maximum size of Ada
109 objects being printed when those objects have a variable type,
110 instead of that maximum size being hardcoded to 65536 bytes.
112 set|show record btrace cpu
113 Controls the processor to be used for enabling errata workarounds for
116 maint check libthread-db
117 Run integrity checks on the current inferior's thread debugging
120 maint set check-libthread-db (on|off)
121 maint show check-libthread-db
122 Control whether to run integrity checks on inferior specific thread
123 debugging libraries as they are loaded. The default is not to
128 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
130 ** The commands attached to a breakpoint can be set by assigning to
131 the breakpoint's "commands" field.
133 ** gdb.execute can now execute multi-line gdb commands.
135 ** The new functions gdb.convenience_variable and
136 gdb.set_convenience_variable can be used to get and set the value
137 of convenience variables.
139 ** A gdb.Parameter will no longer print the "set" help text on an
140 ordinary "set"; instead by default a "set" will be silent unless
141 the get_set_string method returns a non-empty string.
145 RiscV ELF riscv*-*-elf
147 * Removed targets and native configurations
149 m88k running OpenBSD m88*-*-openbsd*
150 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
151 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
152 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
154 * Aarch64/Linux hardware watchpoints improvements
156 Hardware watchpoints on unaligned addresses are now properly
157 supported when running Linux kernel 4.10 or higher: read and access
158 watchpoints are no longer spuriously missed, and all watchpoints
159 lengths between 1 and 8 bytes are supported. On older kernels,
160 watchpoints set on unaligned addresses are no longer missed, with
161 the tradeoff that there is a possibility of false hits being
166 --enable-codesign=CERT
167 This can be used to invoke "codesign -s CERT" after building gdb.
168 This option is useful on macOS, where code signing is required for
169 gdb to work properly.
171 --disable-gdbcli has been removed
172 This is now silently accepted, but does nothing.
174 *** Changes in GDB 8.1
176 * GDB now supports dynamically creating arbitrary register groups specified
177 in XML target descriptions. This allows for finer grain grouping of
178 registers on systems with a large amount of registers.
180 * The 'ptype' command now accepts a '/o' flag, which prints the
181 offsets and sizes of fields in a struct, like the pahole(1) tool.
183 * New "--readnever" command line option instructs GDB to not read each
184 symbol file's symbolic debug information. This makes startup faster
185 but at the expense of not being able to perform symbolic debugging.
186 This option is intended for use cases where symbolic debugging will
187 not be used, e.g., when you only need to dump the debuggee's core.
189 * GDB now uses the GNU MPFR library, if available, to emulate target
190 floating-point arithmetic during expression evaluation when the target
191 uses different floating-point formats than the host. At least version
192 3.1 of GNU MPFR is required.
194 * GDB now supports access to the guarded-storage-control registers and the
195 software-based guarded-storage broadcast control registers on IBM z14.
197 * On Unix systems, GDB now supports transmitting environment variables
198 that are to be set or unset to GDBserver. These variables will
199 affect the environment to be passed to the remote inferior.
201 To inform GDB of environment variables that are to be transmitted to
202 GDBserver, use the "set environment" command. Only user set
203 environment variables are sent to GDBserver.
205 To inform GDB of environment variables that are to be unset before
206 the remote inferior is started by the GDBserver, use the "unset
207 environment" command.
209 * Completion improvements
211 ** GDB can now complete function parameters in linespecs and
212 explicit locations without quoting. When setting breakpoints,
213 quoting around functions names to help with TAB-completion is
214 generally no longer necessary. For example, this now completes
217 (gdb) b function(in[TAB]
218 (gdb) b function(int)
220 Related, GDB is no longer confused with completing functions in
221 C++ anonymous namespaces:
224 (gdb) b (anonymous namespace)::[TAB][TAB]
225 (anonymous namespace)::a_function()
226 (anonymous namespace)::b_function()
228 ** GDB now has much improved linespec and explicit locations TAB
229 completion support, that better understands what you're
230 completing and offers better suggestions. For example, GDB no
231 longer offers data symbols as possible completions when you're
232 setting a breakpoint.
234 ** GDB now TAB-completes label symbol names.
236 ** The "complete" command now mimics TAB completion accurately.
238 * New command line options (gcore)
241 Dump all memory mappings.
243 * Breakpoints on C++ functions are now set on all scopes by default
245 By default, breakpoints on functions/methods are now interpreted as
246 specifying all functions with the given name ignoring missing
247 leading scopes (namespaces and classes).
249 For example, assuming a C++ program with symbols named:
254 both commands "break func()" and "break B::func()" set a breakpoint
257 You can use the new flag "-qualified" to override this. This makes
258 GDB interpret the specified function name as a complete
259 fully-qualified name instead. For example, using the same C++
260 program, the "break -q B::func" command sets a breakpoint on
261 "B::func", only. A parameter has been added to the Python
262 gdb.Breakpoint constructor to achieve the same result when creating
263 a breakpoint from Python.
265 * Breakpoints on functions marked with C++ ABI tags
267 GDB can now set breakpoints on functions marked with C++ ABI tags
268 (e.g., [abi:cxx11]). See here for a description of ABI tags:
269 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
271 Functions with a C++11 abi tag are demangled/displayed like this:
273 function[abi:cxx11](int)
276 You can now set a breakpoint on such functions simply as if they had
279 (gdb) b function(int)
281 Or if you need to disambiguate between tags, like:
283 (gdb) b function[abi:other_tag](int)
285 Tab completion was adjusted accordingly as well.
289 ** New events gdb.new_inferior, gdb.inferior_deleted, and
290 gdb.new_thread are emitted. See the manual for further
291 description of these.
293 ** A new function, "gdb.rbreak" has been added to the Python API.
294 This function allows the setting of a large number of breakpoints
295 via a regex pattern in Python. See the manual for further details.
297 ** Python breakpoints can now accept explicit locations. See the
298 manual for a further description of this feature.
301 * New features in the GDB remote stub, GDBserver
303 ** GDBserver is now able to start inferior processes with a
304 specified initial working directory.
306 The user can set the desired working directory to be used from
307 GDB using the new "set cwd" command.
309 ** New "--selftest" command line option runs some GDBserver self
310 tests. These self tests are disabled in releases.
312 ** On Unix systems, GDBserver now does globbing expansion and variable
313 substitution in inferior command line arguments.
315 This is done by starting inferiors using a shell, like GDB does.
316 See "set startup-with-shell" in the user manual for how to disable
317 this from GDB when using "target extended-remote". When using
318 "target remote", you can disable the startup with shell by using the
319 new "--no-startup-with-shell" GDBserver command line option.
321 ** On Unix systems, GDBserver now supports receiving environment
322 variables that are to be set or unset from GDB. These variables
323 will affect the environment to be passed to the inferior.
325 * When catching an Ada exception raised with a message, GDB now prints
326 the message in the catchpoint hit notification. In GDB/MI mode, that
327 information is provided as an extra field named "exception-message"
328 in the *stopped notification.
330 * Trait objects can now be inspected When debugging Rust code. This
331 requires compiler support which will appear in Rust 1.24.
335 QEnvironmentHexEncoded
336 Inform GDBserver of an environment variable that is to be passed to
337 the inferior when starting it.
340 Inform GDBserver of an environment variable that is to be unset
341 before starting the remote inferior.
344 Inform GDBserver that the environment should be reset (i.e.,
345 user-set environment variables should be unset).
348 Indicates whether the inferior must be started with a shell or not.
351 Tell GDBserver that the inferior to be started should use a specific
354 * The "maintenance print c-tdesc" command now takes an optional
355 argument which is the file name of XML target description.
357 * The "maintenance selftest" command now takes an optional argument to
358 filter the tests to be run.
360 * The "enable", and "disable" commands now accept a range of
361 breakpoint locations, e.g. "enable 1.3-5".
366 Set and show the current working directory for the inferior.
369 Set and show compilation command used for compiling and injecting code
370 with the 'compile' commands.
372 set debug separate-debug-file
373 show debug separate-debug-file
374 Control the display of debug output about separate debug file search.
376 set dump-excluded-mappings
377 show dump-excluded-mappings
378 Control whether mappings marked with the VM_DONTDUMP flag should be
379 dumped when generating a core file.
382 List the registered selftests.
385 Start the debugged program stopping at the first instruction.
388 Control display of debugging messages related to OpenRISC targets.
390 set|show print type nested-type-limit
391 Set and show the limit of nesting level for nested types that the
392 type printer will show.
394 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
397 * Safer/improved support for debugging with no debug info
399 GDB no longer assumes functions with no debug information return
402 This means that GDB now refuses to call such functions unless you
403 tell it the function's type, by either casting the call to the
404 declared return type, or by casting the function to a function
405 pointer of the right type, and calling that:
407 (gdb) p getenv ("PATH")
408 'getenv' has unknown return type; cast the call to its declared return type
409 (gdb) p (char *) getenv ("PATH")
410 $1 = 0x7fffffffe "/usr/local/bin:/"...
411 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
412 $2 = 0x7fffffffe "/usr/local/bin:/"...
414 Similarly, GDB no longer assumes that global variables with no debug
415 info have type 'int', and refuses to print the variable's value
416 unless you tell it the variable's type:
419 'var' has unknown type; cast it to its declared type
423 * New native configurations
425 FreeBSD/aarch64 aarch64*-*-freebsd*
426 FreeBSD/arm arm*-*-freebsd*
430 FreeBSD/aarch64 aarch64*-*-freebsd*
431 FreeBSD/arm arm*-*-freebsd*
432 OpenRISC ELF or1k*-*-elf
434 * Removed targets and native configurations
436 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
438 *** Changes in GDB 8.0
440 * GDB now supports access to the PKU register on GNU/Linux. The register is
441 added by the Memory Protection Keys for Userspace feature which will be
442 available in future Intel CPUs.
444 * GDB now supports C++11 rvalue references.
448 ** New functions to start, stop and access a running btrace recording.
449 ** Rvalue references are now supported in gdb.Type.
451 * GDB now supports recording and replaying rdrand and rdseed Intel 64
454 * Building GDB and GDBserver now requires a C++11 compiler.
456 For example, GCC 4.8 or later.
458 It is no longer possible to build GDB or GDBserver with a C
459 compiler. The --disable-build-with-cxx configure option has been
462 * Building GDB and GDBserver now requires GNU make >= 3.81.
464 It is no longer supported to build GDB or GDBserver with another
465 implementation of the make program or an earlier version of GNU make.
467 * Native debugging on MS-Windows supports command-line redirection
469 Command-line arguments used for starting programs on MS-Windows can
470 now include redirection symbols supported by native Windows shells,
471 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
472 as "run", "start", and "set args", as well as the corresponding MI
475 * Support for thread names on MS-Windows.
477 GDB now catches and handles the special exception that programs
478 running on MS-Windows use to assign names to threads in the
481 * Support for Java programs compiled with gcj has been removed.
483 * User commands now accept an unlimited number of arguments.
484 Previously, only up to 10 was accepted.
486 * The "eval" command now expands user-defined command arguments.
488 This makes it easier to process a variable number of arguments:
493 eval "print $arg%d", $i
498 * Target descriptions can now describe registers for sparc32 and sparc64.
500 * GDB now supports DWARF version 5 (debug information format).
501 Its .debug_names index is not yet supported.
503 * New native configurations
505 FreeBSD/mips mips*-*-freebsd
509 Synopsys ARC arc*-*-elf32
510 FreeBSD/mips mips*-*-freebsd
512 * Removed targets and native configurations
514 Alpha running FreeBSD alpha*-*-freebsd*
515 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
520 Erases all the flash memory regions reported by the target.
522 maint print arc arc-instruction address
523 Print internal disassembler information about instruction at a given address.
527 set disassembler-options
528 show disassembler-options
529 Controls the passing of target specific information to the disassembler.
530 If it is necessary to specify more than one disassembler option then
531 multiple options can be placed together into a comma separated list.
532 The default value is the empty string. Currently, the only supported
533 targets are ARM, PowerPC and S/390.
538 Erases all the flash memory regions reported by the target. This is
539 equivalent to the CLI command flash-erase.
541 -file-list-shared-libraries
542 List the shared libraries in the program. This is
543 equivalent to the CLI command "info shared".
546 Catchpoints stopping the program when Ada exceptions are
547 handled. This is equivalent to the CLI command "catch handlers".
549 *** Changes in GDB 7.12
551 * GDB and GDBserver now build with a C++ compiler by default.
553 The --enable-build-with-cxx configure option is now enabled by
554 default. One must now explicitly configure with
555 --disable-build-with-cxx in order to build with a C compiler. This
556 option will be removed in a future release.
558 * GDBserver now supports recording btrace without maintaining an active
561 * GDB now supports a negative repeat count in the 'x' command to examine
562 memory backward from the given address. For example:
565 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
566 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
567 (gdb) x/-5i 0x0000000000400580
568 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
569 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
570 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
571 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
572 0x40057b <main(int, char**)+25>:
573 callq 0x400536 <Func1(int, char const*)>
575 * Fortran: Support structures with fields of dynamic types and
576 arrays of dynamic types.
578 * The symbol dumping maintenance commands have new syntax.
579 maint print symbols [-pc address] [--] [filename]
580 maint print symbols [-objfile objfile] [-source source] [--] [filename]
581 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
582 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
583 maint print msymbols [-objfile objfile] [--] [filename]
585 * GDB now supports multibit bitfields and enums in target register
588 * New Python-based convenience function $_as_string(val), which returns
589 the textual representation of a value. This function is especially
590 useful to obtain the text label of an enum value.
592 * Intel MPX bound violation handling.
594 Segmentation faults caused by a Intel MPX boundary violation
595 now display the kind of violation (upper or lower), the memory
596 address accessed and the memory bounds, along with the usual
597 signal received and code location.
601 Program received signal SIGSEGV, Segmentation fault
602 Upper bound violation while accessing address 0x7fffffffc3b3
603 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
604 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
606 * Rust language support.
607 GDB now supports debugging programs written in the Rust programming
608 language. See https://www.rust-lang.org/ for more information about
611 * Support for running interpreters on specified input/output devices
613 GDB now supports a new mechanism that allows frontends to provide
614 fully featured GDB console views, as a better alternative to
615 building such views on top of the "-interpreter-exec console"
616 command. See the new "new-ui" command below. With that command,
617 frontends can now start GDB in the traditional command-line mode
618 running in an embedded terminal emulator widget, and create a
619 separate MI interpreter running on a specified i/o device. In this
620 way, GDB handles line editing, history, tab completion, etc. in the
621 console all by itself, and the GUI uses the separate MI interpreter
622 for its own control and synchronization, invisible to the command
625 * The "catch syscall" command catches groups of related syscalls.
627 The "catch syscall" command now supports catching a group of related
628 syscalls using the 'group:' or 'g:' prefix.
633 skip -gfile file-glob-pattern
634 skip -function function
635 skip -rfunction regular-expression
636 A generalized form of the skip command, with new support for
637 glob-style file names and regular expressions for function names.
638 Additionally, a file spec and a function spec may now be combined.
640 maint info line-table REGEXP
641 Display the contents of GDB's internal line table data struture.
644 Run any GDB unit tests that were compiled in.
647 Start a new user interface instance running INTERP as interpreter,
648 using the TTY file for input/output.
652 ** gdb.Breakpoint objects have a new attribute "pending", which
653 indicates whether the breakpoint is pending.
654 ** Three new breakpoint-related events have been added:
655 gdb.breakpoint_created, gdb.breakpoint_modified, and
656 gdb.breakpoint_deleted.
659 Signal ("set") the given MS-Windows event object. This is used in
660 conjunction with the Windows JIT debugging (AeDebug) support, where
661 the OS suspends a crashing process until a debugger can attach to
662 it. Resuming the crashing process, in order to debug it, is done by
665 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
666 was added in GDBserver, including JIT compiling fast tracepoint's
667 conditional expression bytecode into native code.
669 * Support for various remote target protocols and ROM monitors has
672 target m32rsdi Remote M32R debugging over SDI
673 target mips MIPS remote debugging protocol
674 target pmon PMON ROM monitor
675 target ddb NEC's DDB variant of PMON for Vr4300
676 target rockhopper NEC RockHopper variant of PMON
677 target lsi LSI variant of PMO
679 * Support for tracepoints and fast tracepoints on powerpc-linux,
680 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
681 including JIT compiling fast tracepoint's conditional expression
682 bytecode into native code.
684 * MI async record =record-started now includes the method and format used for
685 recording. For example:
687 =record-started,thread-group="i1",method="btrace",format="bts"
689 * MI async record =thread-selected now includes the frame field. For example:
691 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
695 Andes NDS32 nds32*-*-elf
697 *** Changes in GDB 7.11
699 * GDB now supports debugging kernel-based threads on FreeBSD.
701 * Per-inferior thread numbers
703 Thread numbers are now per inferior instead of global. If you're
704 debugging multiple inferiors, GDB displays thread IDs using a
705 qualified INF_NUM.THR_NUM form. For example:
709 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
710 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
711 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
712 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
714 As consequence, thread numbers as visible in the $_thread
715 convenience variable and in Python's InferiorThread.num attribute
716 are no longer unique between inferiors.
718 GDB now maintains a second thread ID per thread, referred to as the
719 global thread ID, which is the new equivalent of thread numbers in
720 previous releases. See also $_gthread below.
722 For backwards compatibility, MI's thread IDs always refer to global
725 * Commands that accept thread IDs now accept the qualified
726 INF_NUM.THR_NUM form as well. For example:
729 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
732 * In commands that accept a list of thread IDs, you can now refer to
733 all threads of an inferior using a star wildcard. GDB accepts
734 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
735 refer to all threads of the current inferior. For example, "info
738 * You can use "info threads -gid" to display the global thread ID of
741 * The new convenience variable $_gthread holds the global number of
744 * The new convenience variable $_inferior holds the number of the
747 * GDB now displays the ID and name of the thread that hit a breakpoint
748 or received a signal, if your program is multi-threaded. For
751 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
752 Thread 1 "main" received signal SIGINT, Interrupt.
754 * Record btrace now supports non-stop mode.
756 * Support for tracepoints on aarch64-linux was added in GDBserver.
758 * The 'record instruction-history' command now indicates speculative execution
759 when using the Intel Processor Trace recording format.
761 * GDB now allows users to specify explicit locations, bypassing
762 the linespec parser. This feature is also available to GDB/MI
765 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
766 GDB now is able to debug both AArch64 applications and ARM applications
769 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
770 including JIT compiling fast tracepoint's conditional expression bytecode
773 * GDB now supports displaced stepping on AArch64 GNU/Linux.
775 * "info threads", "info inferiors", "info display", "info checkpoints"
776 and "maint info program-spaces" now list the corresponding items in
777 ascending ID order, for consistency with all other "info" commands.
779 * In Ada, the overloads selection menu has been enhanced to display the
780 parameter types and the return types for the matching overloaded subprograms.
784 maint set target-non-stop (on|off|auto)
785 maint show target-non-stop
786 Control whether GDB targets always operate in non-stop mode even if
787 "set non-stop" is "off". The default is "auto", meaning non-stop
788 mode is enabled if supported by the target.
790 maint set bfd-sharing
791 maint show bfd-sharing
792 Control the reuse of bfd objects.
796 Control display of debugging info regarding bfd caching.
800 Control display of debugging info regarding FreeBSD threads.
802 set remote multiprocess-extensions-packet
803 show remote multiprocess-extensions-packet
804 Set/show the use of the remote protocol multiprocess extensions.
806 set remote thread-events
807 show remote thread-events
808 Set/show the use of thread create/exit events.
810 set ada print-signatures on|off
811 show ada print-signatures"
812 Control whether parameter types and return types are displayed in overloads
813 selection menus. It is activaled (@code{on}) by default.
817 Controls the maximum size of memory, in bytes, that GDB will
818 allocate for value contents. Prevents incorrect programs from
819 causing GDB to allocate overly large buffers. Default is 64k.
821 * The "disassemble" command accepts a new modifier: /s.
822 It prints mixed source+disassembly like /m with two differences:
823 - disassembled instructions are now printed in program order, and
824 - and source for all relevant files is now printed.
825 The "/m" option is now considered deprecated: its "source-centric"
826 output hasn't proved useful in practice.
828 * The "record instruction-history" command accepts a new modifier: /s.
829 It behaves exactly like /m and prints mixed source+disassembly.
831 * The "set scheduler-locking" command supports a new mode "replay".
832 It behaves like "off" in record mode and like "on" in replay mode.
834 * Support for various ROM monitors has been removed:
836 target dbug dBUG ROM monitor for Motorola ColdFire
837 target picobug Motorola picobug monitor
838 target dink32 DINK32 ROM monitor for PowerPC
839 target m32r Renesas M32R/D ROM monitor
840 target mon2000 mon2000 ROM monitor
841 target ppcbug PPCBUG ROM monitor for PowerPC
843 * Support for reading/writing memory and extracting values on architectures
844 whose memory is addressable in units of any integral multiple of 8 bits.
847 Allows to break when an Ada exception is handled.
852 Indicates that an exec system call was executed.
854 exec-events feature in qSupported
855 The qSupported packet allows GDB to request support for exec
856 events using the new 'gdbfeature' exec-event, and the qSupported
857 response can contain the corresponding 'stubfeature'. Set and
858 show commands can be used to display whether these features are enabled.
861 Equivalent to interrupting with the ^C character, but works in
864 thread created stop reason (T05 create:...)
865 Indicates that the thread was just created and is stopped at entry.
867 thread exit stop reply (w exitcode;tid)
868 Indicates that the thread has terminated.
871 Enables/disables thread create and exit event reporting. For
872 example, this is used in non-stop mode when GDB stops a set of
873 threads and synchronously waits for the their corresponding stop
874 replies. Without exit events, if one of the threads exits, GDB
875 would hang forever not knowing that it should no longer expect a
876 stop for that same thread.
879 Indicates that there are no resumed threads left in the target (all
880 threads are stopped). The remote stub reports support for this stop
881 reply to GDB's qSupported query.
884 Enables/disables catching syscalls from the inferior process.
885 The remote stub reports support for this packet to GDB's qSupported query.
887 syscall_entry stop reason
888 Indicates that a syscall was just called.
890 syscall_return stop reason
891 Indicates that a syscall just returned.
893 * Extended-remote exec events
895 ** GDB now has support for exec events on extended-remote Linux targets.
896 For such targets with Linux kernels 2.5.46 and later, this enables
897 follow-exec-mode and exec catchpoints.
899 set remote exec-event-feature-packet
900 show remote exec-event-feature-packet
901 Set/show the use of the remote exec event feature.
903 * Thread names in remote protocol
905 The reply to qXfer:threads:read may now include a name attribute for each
908 * Target remote mode fork and exec events
910 ** GDB now has support for fork and exec events on target remote mode
911 Linux targets. For such targets with Linux kernels 2.5.46 and later,
912 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
913 fork and exec catchpoints.
915 * Remote syscall events
917 ** GDB now has support for catch syscall on remote Linux targets,
918 currently enabled on x86/x86_64 architectures.
920 set remote catch-syscall-packet
921 show remote catch-syscall-packet
922 Set/show the use of the remote catch syscall feature.
926 ** The -var-set-format command now accepts the zero-hexadecimal
927 format. It outputs data in hexadecimal format with zero-padding on the
932 ** gdb.InferiorThread objects have a new attribute "global_num",
933 which refers to the thread's global thread ID. The existing
934 "num" attribute now refers to the thread's per-inferior number.
935 See "Per-inferior thread numbers" above.
936 ** gdb.InferiorThread objects have a new attribute "inferior", which
937 is the Inferior object the thread belongs to.
939 *** Changes in GDB 7.10
941 * Support for process record-replay and reverse debugging on aarch64*-linux*
942 targets has been added. GDB now supports recording of A64 instruction set
943 including advance SIMD instructions.
945 * Support for Sun's version of the "stabs" debug file format has been removed.
947 * GDB now honors the content of the file /proc/PID/coredump_filter
948 (PID is the process ID) on GNU/Linux systems. This file can be used
949 to specify the types of memory mappings that will be included in a
950 corefile. For more information, please refer to the manual page of
951 "core(5)". GDB also has a new command: "set use-coredump-filter
952 on|off". It allows to set whether GDB will read the content of the
953 /proc/PID/coredump_filter file when generating a corefile.
955 * The "info os" command on GNU/Linux can now display information on
957 "info os cpus" Listing of all cpus/cores on the system
959 * GDB has two new commands: "set serial parity odd|even|none" and
960 "show serial parity". These allows to set or show parity for the
963 * The "info source" command now displays the producer string if it was
964 present in the debug info. This typically includes the compiler version
965 and may include things like its command line arguments.
967 * The "info dll", an alias of the "info sharedlibrary" command,
968 is now available on all platforms.
970 * Directory names supplied to the "set sysroot" commands may be
971 prefixed with "target:" to tell GDB to access shared libraries from
972 the target system, be it local or remote. This replaces the prefix
973 "remote:". The default sysroot has been changed from "" to
974 "target:". "remote:" is automatically converted to "target:" for
975 backward compatibility.
977 * The system root specified by "set sysroot" will be prepended to the
978 filename of the main executable (if reported to GDB as absolute by
979 the operating system) when starting processes remotely, and when
980 attaching to already-running local or remote processes.
982 * GDB now supports automatic location and retrieval of executable
983 files from remote targets. Remote debugging can now be initiated
984 using only a "target remote" or "target extended-remote" command
985 (no "set sysroot" or "file" commands are required). See "New remote
988 * The "dump" command now supports verilog hex format.
990 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
992 * On GNU/Linux, GDB and gdbserver are now able to access executable
993 and shared library files without a "set sysroot" command when
994 attaching to processes running in different mount namespaces from
995 the debugger. This makes it possible to attach to processes in
996 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
997 See "New remote packets" below.
999 * The "tui reg" command now provides completion for all of the
1000 available register groups, including target specific groups.
1002 * The HISTSIZE environment variable is no longer read when determining
1003 the size of GDB's command history. GDB now instead reads the dedicated
1004 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1005 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1010 ** Memory ports can now be unbuffered.
1014 ** gdb.Objfile objects have a new attribute "username",
1015 which is the name of the objfile as specified by the user,
1016 without, for example, resolving symlinks.
1017 ** You can now write frame unwinders in Python.
1018 ** gdb.Type objects have a new method "optimized_out",
1019 returning optimized out gdb.Value instance of this type.
1020 ** gdb.Value objects have new methods "reference_value" and
1021 "const_value" which return a reference to the value and a
1022 "const" version of the value respectively.
1026 maint print symbol-cache
1027 Print the contents of the symbol cache.
1029 maint print symbol-cache-statistics
1030 Print statistics of symbol cache usage.
1032 maint flush-symbol-cache
1033 Flush the contents of the symbol cache.
1037 Start branch trace recording using Branch Trace Store (BTS) format.
1040 Evaluate expression by using the compiler and print result.
1044 Explicit commands for enabling and disabling tui mode.
1047 set mpx bound on i386 and amd64
1048 Support for bound table investigation on Intel MPX enabled applications.
1052 Start branch trace recording using Intel Processor Trace format.
1055 Print information about branch tracing internals.
1057 maint btrace packet-history
1058 Print the raw branch tracing data.
1060 maint btrace clear-packet-history
1061 Discard the stored raw branch tracing data.
1064 Discard all branch tracing data. It will be fetched and processed
1065 anew by the next "record" command.
1070 Renamed from "set debug dwarf2-die".
1071 show debug dwarf-die
1072 Renamed from "show debug dwarf2-die".
1074 set debug dwarf-read
1075 Renamed from "set debug dwarf2-read".
1076 show debug dwarf-read
1077 Renamed from "show debug dwarf2-read".
1079 maint set dwarf always-disassemble
1080 Renamed from "maint set dwarf2 always-disassemble".
1081 maint show dwarf always-disassemble
1082 Renamed from "maint show dwarf2 always-disassemble".
1084 maint set dwarf max-cache-age
1085 Renamed from "maint set dwarf2 max-cache-age".
1086 maint show dwarf max-cache-age
1087 Renamed from "maint show dwarf2 max-cache-age".
1089 set debug dwarf-line
1090 show debug dwarf-line
1091 Control display of debugging info regarding DWARF line processing.
1094 show max-completions
1095 Set the maximum number of candidates to be considered during
1096 completion. The default value is 200. This limit allows GDB
1097 to avoid generating large completion lists, the computation of
1098 which can cause the debugger to become temporarily unresponsive.
1100 set history remove-duplicates
1101 show history remove-duplicates
1102 Control the removal of duplicate history entries.
1104 maint set symbol-cache-size
1105 maint show symbol-cache-size
1106 Control the size of the symbol cache.
1108 set|show record btrace bts buffer-size
1109 Set and show the size of the ring buffer used for branch tracing in
1111 The obtained size may differ from the requested size. Use "info
1112 record" to see the obtained buffer size.
1114 set debug linux-namespaces
1115 show debug linux-namespaces
1116 Control display of debugging info regarding Linux namespaces.
1118 set|show record btrace pt buffer-size
1119 Set and show the size of the ring buffer used for branch tracing in
1120 Intel Processor Trace format.
1121 The obtained size may differ from the requested size. Use "info
1122 record" to see the obtained buffer size.
1124 maint set|show btrace pt skip-pad
1125 Set and show whether PAD packets are skipped when computing the
1128 * The command 'thread apply all' can now support new option '-ascending'
1129 to call its specified command for all threads in ascending order.
1131 * Python/Guile scripting
1133 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1134 special section named `.debug_gdb_scripts'.
1136 * New remote packets
1138 qXfer:btrace-conf:read
1139 Return the branch trace configuration for the current thread.
1141 Qbtrace-conf:bts:size
1142 Set the requested ring buffer size for branch tracing in BTS format.
1145 Enable Intel Procesor Trace-based branch tracing for the current
1146 process. The remote stub reports support for this packet to GDB's
1149 Qbtrace-conf:pt:size
1150 Set the requested ring buffer size for branch tracing in Intel Processor
1154 Indicates a memory breakpoint instruction was executed, irrespective
1155 of whether it was GDB that planted the breakpoint or the breakpoint
1156 is hardcoded in the program. This is required for correct non-stop
1160 Indicates the target stopped for a hardware breakpoint. This is
1161 required for correct non-stop mode operation.
1164 Return information about files on the remote system.
1166 qXfer:exec-file:read
1167 Return the full absolute name of the file that was executed to
1168 create a process running on the remote system.
1171 Select the filesystem on which vFile: operations with filename
1172 arguments will operate. This is required for GDB to be able to
1173 access files on remote targets where the remote stub does not
1174 share a common filesystem with the inferior(s).
1177 Indicates that a fork system call was executed.
1180 Indicates that a vfork system call was executed.
1182 vforkdone stop reason
1183 Indicates that a vfork child of the specified process has executed
1184 an exec or exit, allowing the vfork parent to resume execution.
1186 fork-events and vfork-events features in qSupported
1187 The qSupported packet allows GDB to request support for fork and
1188 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1189 and the qSupported response can contain the corresponding
1190 'stubfeatures'. Set and show commands can be used to display
1191 whether these features are enabled.
1193 * Extended-remote fork events
1195 ** GDB now has support for fork events on extended-remote Linux
1196 targets. For targets with Linux kernels 2.5.60 and later, this
1197 enables follow-fork-mode and detach-on-fork for both fork and
1198 vfork, as well as fork and vfork catchpoints.
1200 * The info record command now shows the recording format and the
1201 branch tracing configuration for the current thread when using
1202 the btrace record target.
1203 For the BTS format, it shows the ring buffer size.
1205 * GDB now has support for DTrace USDT (Userland Static Defined
1206 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1208 * GDB now supports access to vector registers on S/390 GNU/Linux
1211 * Removed command line options
1213 -xdb HP-UX XDB compatibility mode.
1215 * Removed targets and native configurations
1217 HP/PA running HP-UX hppa*-*-hpux*
1218 Itanium running HP-UX ia64-*-hpux*
1220 * New configure options
1223 This configure option allows the user to build GDB with support for
1224 Intel Processor Trace (default: auto). This requires libipt.
1226 --with-libipt-prefix=PATH
1227 Specify the path to the version of libipt that GDB should use.
1228 $PATH/include should contain the intel-pt.h header and
1229 $PATH/lib should contain the libipt.so library.
1231 *** Changes in GDB 7.9.1
1235 ** Xmethods can now specify a result type.
1237 *** Changes in GDB 7.9
1239 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1243 ** You can now access frame registers from Python scripts.
1244 ** New attribute 'producer' for gdb.Symtab objects.
1245 ** gdb.Objfile objects have a new attribute "progspace",
1246 which is the gdb.Progspace object of the containing program space.
1247 ** gdb.Objfile objects have a new attribute "owner".
1248 ** gdb.Objfile objects have a new attribute "build_id",
1249 which is the build ID generated when the file was built.
1250 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1251 ** A new event "gdb.clear_objfiles" has been added, triggered when
1252 selecting a new file to debug.
1253 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1254 ** New function gdb.lookup_objfile.
1256 New events which are triggered when GDB modifies the state of the
1259 ** gdb.events.inferior_call_pre: Function call is about to be made.
1260 ** gdb.events.inferior_call_post: Function call has just been made.
1261 ** gdb.events.memory_changed: A memory location has been altered.
1262 ** gdb.events.register_changed: A register has been altered.
1264 * New Python-based convenience functions:
1266 ** $_caller_is(name [, number_of_frames])
1267 ** $_caller_matches(regexp [, number_of_frames])
1268 ** $_any_caller_is(name [, number_of_frames])
1269 ** $_any_caller_matches(regexp [, number_of_frames])
1271 * GDB now supports the compilation and injection of source code into
1272 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1273 to compile the source code to object code, and if successful, inject
1274 and execute that code within the current context of the inferior.
1275 Currently the C language is supported. The commands used to
1276 interface with this new feature are:
1278 compile code [-raw|-r] [--] [source code]
1279 compile file [-raw|-r] filename
1283 demangle [-l language] [--] name
1284 Demangle "name" in the specified language, or the current language
1285 if elided. This command is renamed from the "maint demangle" command.
1286 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1287 as "maint demangler-warning".
1289 queue-signal signal-name-or-number
1290 Queue a signal to be delivered to the thread when it is resumed.
1292 add-auto-load-scripts-directory directory
1293 Add entries to the list of directories from which to load auto-loaded
1296 maint print user-registers
1297 List all currently available "user" registers.
1299 compile code [-r|-raw] [--] [source code]
1300 Compile, inject, and execute in the inferior the executable object
1301 code produced by compiling the provided source code.
1303 compile file [-r|-raw] filename
1304 Compile and inject into the inferior the executable object code
1305 produced by compiling the source code stored in the filename
1308 * On resume, GDB now always passes the signal the program had stopped
1309 for to the thread the signal was sent to, even if the user changed
1310 threads before resuming. Previously GDB would often (but not
1311 always) deliver the signal to the thread that happens to be current
1314 * Conversely, the "signal" command now consistently delivers the
1315 requested signal to the current thread. GDB now asks for
1316 confirmation if the program had stopped for a signal and the user
1317 switched threads meanwhile.
1319 * "breakpoint always-inserted" modes "off" and "auto" merged.
1321 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1322 won't remove breakpoints from the target until all threads stop,
1323 even in non-stop mode. The "auto" mode has been removed, and "off"
1324 is now the default mode.
1328 set debug symbol-lookup
1329 show debug symbol-lookup
1330 Control display of debugging info regarding symbol lookup.
1334 ** The -list-thread-groups command outputs an exit-code field for
1335 inferiors that have exited.
1339 MIPS SDE mips*-sde*-elf*
1343 Support for these obsolete configurations has been removed.
1345 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1346 SGI Irix-5.x mips-*-irix5*
1347 SGI Irix-6.x mips-*-irix6*
1348 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1349 VAX running Ultrix vax-*-ultrix*
1351 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1352 and "assf"), have been removed. Use the "sharedlibrary" command, or
1353 its alias "share", instead.
1355 *** Changes in GDB 7.8
1357 * New command line options
1360 This is an alias for the --data-directory option.
1362 * GDB supports printing and modifying of variable length automatic arrays
1363 as specified in ISO C99.
1365 * The ARM simulator now supports instruction level tracing
1366 with or without disassembly.
1370 GDB now has support for scripting using Guile. Whether this is
1371 available is determined at configure time.
1372 Guile version 2.0 or greater is required.
1373 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1375 * New commands (for set/show, see "New options" below)
1379 Invoke CODE by passing it to the Guile interpreter.
1383 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1385 info auto-load guile-scripts [regexp]
1386 Print the list of automatically loaded Guile scripts.
1388 * The source command is now capable of sourcing Guile scripts.
1389 This feature is dependent on the debugger being built with Guile support.
1393 set print symbol-loading (off|brief|full)
1394 show print symbol-loading
1395 Control whether to print informational messages when loading symbol
1396 information for a file. The default is "full", but when debugging
1397 programs with large numbers of shared libraries the amount of output
1398 becomes less useful.
1400 set guile print-stack (none|message|full)
1401 show guile print-stack
1402 Show a stack trace when an error is encountered in a Guile script.
1404 set auto-load guile-scripts (on|off)
1405 show auto-load guile-scripts
1406 Control auto-loading of Guile script files.
1408 maint ada set ignore-descriptive-types (on|off)
1409 maint ada show ignore-descriptive-types
1410 Control whether the debugger should ignore descriptive types in Ada
1411 programs. The default is not to ignore the descriptive types. See
1412 the user manual for more details on descriptive types and the intended
1413 usage of this option.
1415 set auto-connect-native-target
1417 Control whether GDB is allowed to automatically connect to the
1418 native target for the run, attach, etc. commands when not connected
1419 to any target yet. See also "target native" below.
1421 set record btrace replay-memory-access (read-only|read-write)
1422 show record btrace replay-memory-access
1423 Control what memory accesses are allowed during replay.
1425 maint set target-async (on|off)
1426 maint show target-async
1427 This controls whether GDB targets operate in synchronous or
1428 asynchronous mode. Normally the default is asynchronous, if it is
1429 available; but this can be changed to more easily debug problems
1430 occurring only in synchronous mode.
1432 set mi-async (on|off)
1434 Control whether MI asynchronous mode is preferred. This supersedes
1435 "set target-async" of previous GDB versions.
1437 * "set target-async" is deprecated as a CLI option and is now an alias
1438 for "set mi-async" (only puts MI into async mode).
1440 * Background execution commands (e.g., "c&", "s&", etc.) are now
1441 possible ``out of the box'' if the target supports them. Previously
1442 the user would need to explicitly enable the possibility with the
1443 "set target-async on" command.
1445 * New features in the GDB remote stub, GDBserver
1447 ** New option --debug-format=option1[,option2,...] allows one to add
1448 additional text to each output. At present only timestamps
1449 are supported: --debug-format=timestamps.
1450 Timestamps can also be turned on with the
1451 "monitor set debug-format timestamps" command from GDB.
1453 * The 'record instruction-history' command now starts counting instructions
1454 at one. This also affects the instruction ranges reported by the
1455 'record function-call-history' command when given the /i modifier.
1457 * The command 'record function-call-history' supports a new modifier '/c' to
1458 indent the function names based on their call stack depth.
1459 The fields for the '/i' and '/l' modifier have been reordered.
1460 The source line range is now prefixed with 'at'.
1461 The instruction range is now prefixed with 'inst'.
1462 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1463 "record instruction-history" and "list" commands.
1465 * The ranges given as arguments to the 'record function-call-history' and
1466 'record instruction-history' commands are now inclusive.
1468 * The btrace record target now supports the 'record goto' command.
1469 For locations inside the execution trace, the back trace is computed
1470 based on the information stored in the execution trace.
1472 * The btrace record target supports limited reverse execution and replay.
1473 The target does not record data and therefore does not allow reading
1474 memory or registers.
1476 * The "catch syscall" command now works on s390*-linux* targets.
1478 * The "compare-sections" command is no longer specific to target
1479 remote. It now works with all targets.
1481 * All native targets are now consistently called "native".
1482 Consequently, the "target child", "target GNU", "target djgpp",
1483 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1484 commands have been replaced with "target native". The QNX/NTO port
1485 leaves the "procfs" target in place and adds a "native" target for
1486 consistency with other ports. The impact on users should be minimal
1487 as these commands previously either throwed an error, or were
1488 no-ops. The target's name is visible in the output of the following
1489 commands: "help target", "info target", "info files", "maint print
1492 * The "target native" command now connects to the native target. This
1493 can be used to launch native programs even when "set
1494 auto-connect-native-target" is set to off.
1496 * GDB now supports access to Intel MPX registers on GNU/Linux.
1498 * Support for Intel AVX-512 registers on GNU/Linux.
1499 Support displaying and modifying Intel AVX-512 registers
1500 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1502 * New remote packets
1504 qXfer:btrace:read's annex
1505 The qXfer:btrace:read packet supports a new annex 'delta' to read
1506 branch trace incrementally.
1510 ** Valid Python operations on gdb.Value objects representing
1511 structs/classes invoke the corresponding overloaded operators if
1513 ** New `Xmethods' feature in the Python API. Xmethods are
1514 additional methods or replacements for existing methods of a C++
1515 class. This feature is useful for those cases where a method
1516 defined in C++ source code could be inlined or optimized out by
1517 the compiler, making it unavailable to GDB.
1520 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1522 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1523 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1524 its alias "share", instead.
1526 * The commands "set remotebaud" and "show remotebaud" are no longer
1527 supported. Use "set serial baud" and "show serial baud" (respectively)
1532 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1533 target-async". The latter is left as a deprecated alias of the
1534 former for backward compatibility. If the target supports it,
1535 CLI background execution commands are now always possible by
1536 default, independently of whether the frontend stated a
1537 preference for asynchronous execution with "-gdb-set mi-async".
1538 Previously "-gdb-set target-async off" affected both MI execution
1539 commands and CLI execution commands.
1541 *** Changes in GDB 7.7
1543 * Improved support for process record-replay and reverse debugging on
1544 arm*-linux* targets. Support for thumb32 and syscall instruction
1545 recording has been added.
1547 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1549 * GDB now supports Fission DWP file format version 2.
1550 http://gcc.gnu.org/wiki/DebugFission
1552 * New convenience function "$_isvoid", to check whether an expression
1553 is void. A void expression is an expression where the type of the
1554 result is "void". For example, some convenience variables may be
1555 "void" when evaluated (e.g., "$_exitcode" before the execution of
1556 the program being debugged; or an undefined convenience variable).
1557 Another example, when calling a function whose return type is
1560 * The "maintenance print objfiles" command now takes an optional regexp.
1562 * The "catch syscall" command now works on arm*-linux* targets.
1564 * GDB now consistently shows "<not saved>" when printing values of
1565 registers the debug info indicates have not been saved in the frame
1566 and there's nowhere to retrieve them from
1567 (callee-saved/call-clobbered registers):
1572 (gdb) info registers rax
1575 Before, the former would print "<optimized out>", and the latter
1576 "*value not available*".
1578 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1583 ** Frame filters and frame decorators have been added.
1584 ** Temporary breakpoints are now supported.
1585 ** Line tables representation has been added.
1586 ** New attribute 'parent_type' for gdb.Field objects.
1587 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1588 ** New attribute 'name' for gdb.Type objects.
1592 Nios II ELF nios2*-*-elf
1593 Nios II GNU/Linux nios2*-*-linux
1594 Texas Instruments MSP430 msp430*-*-elf
1596 * Removed native configurations
1598 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1599 been removed. ELF variants of these configurations are kept supported.
1601 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1602 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1603 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1604 i[34567]86-*-openbsd3.[0-3]
1605 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1606 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1607 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1611 Like "catch throw", but catches a re-thrown exception.
1612 maint check-psymtabs
1613 Renamed from old "maint check-symtabs".
1615 Perform consistency checks on symtabs.
1616 maint expand-symtabs
1617 Expand symtabs matching an optional regexp.
1620 Display the details of GDB configure-time options.
1622 maint set|show per-command
1623 maint set|show per-command space
1624 maint set|show per-command time
1625 maint set|show per-command symtab
1626 Enable display of per-command gdb resource usage.
1628 remove-symbol-file FILENAME
1629 remove-symbol-file -a ADDRESS
1630 Remove a symbol file added via add-symbol-file. The file to remove
1631 can be identified by its filename or by an address that lies within
1632 the boundaries of this symbol file in memory.
1635 info exceptions REGEXP
1636 Display the list of Ada exceptions defined in the program being
1637 debugged. If provided, only the exceptions whose names match REGEXP
1642 set debug symfile off|on
1644 Control display of debugging info regarding reading symbol files and
1645 symbol tables within those files
1647 set print raw frame-arguments
1648 show print raw frame-arguments
1649 Set/show whether to print frame arguments in raw mode,
1650 disregarding any defined pretty-printers.
1652 set remote trace-status-packet
1653 show remote trace-status-packet
1654 Set/show the use of remote protocol qTStatus packet.
1658 Control display of debugging messages related to Nios II targets.
1662 Control whether target-assisted range stepping is enabled.
1664 set startup-with-shell
1665 show startup-with-shell
1666 Specifies whether Unix child processes are started via a shell or
1671 Use the target memory cache for accesses to the code segment. This
1672 improves performance of remote debugging (particularly disassembly).
1674 * You can now use a literal value 'unlimited' for options that
1675 interpret 0 or -1 as meaning "unlimited". E.g., "set
1676 trace-buffer-size unlimited" is now an alias for "set
1677 trace-buffer-size -1" and "set height unlimited" is now an alias for
1680 * The "set debug symtab-create" debugging option of GDB has been changed to
1681 accept a verbosity level. 0 means "off", 1 provides basic debugging
1682 output, and values of 2 or greater provides more verbose output.
1684 * New command-line options
1686 Display the details of GDB configure-time options.
1688 * The command 'tsave' can now support new option '-ctf' to save trace
1689 buffer in Common Trace Format.
1691 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1694 * GDB now implements the the C++ 'typeid' operator.
1696 * The new convenience variable $_exception holds the exception being
1697 thrown or caught at an exception-related catchpoint.
1699 * The exception-related catchpoints, like "catch throw", now accept a
1700 regular expression which can be used to filter exceptions by type.
1702 * The new convenience variable $_exitsignal is automatically set to
1703 the terminating signal number when the program being debugged dies
1704 due to an uncaught signal.
1708 ** All MI commands now accept an optional "--language" option.
1709 Support for this feature can be verified by using the "-list-features"
1710 command, which should contain "language-option".
1712 ** The new command -info-gdb-mi-command allows the user to determine
1713 whether a GDB/MI command is supported or not.
1715 ** The "^error" result record returned when trying to execute an undefined
1716 GDB/MI command now provides a variable named "code" whose content is the
1717 "undefined-command" error code. Support for this feature can be verified
1718 by using the "-list-features" command, which should contain
1719 "undefined-command-error-code".
1721 ** The -trace-save MI command can optionally save trace buffer in Common
1724 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1726 ** The command -data-list-register-values now accepts an optional
1727 "--skip-unavailable" option. When used, only the available registers
1730 ** The new command -trace-frame-collected dumps collected variables,
1731 computed expressions, tvars, memory and registers in a traceframe.
1733 ** The commands -stack-list-locals, -stack-list-arguments and
1734 -stack-list-variables now accept an option "--skip-unavailable".
1735 When used, only the available locals or arguments are displayed.
1737 ** The -exec-run command now accepts an optional "--start" option.
1738 When used, the command follows the same semantics as the "start"
1739 command, stopping the program's execution at the start of its
1740 main subprogram. Support for this feature can be verified using
1741 the "-list-features" command, which should contain
1742 "exec-run-start-option".
1744 ** The new commands -catch-assert and -catch-exceptions insert
1745 catchpoints stopping the program when Ada exceptions are raised.
1747 ** The new command -info-ada-exceptions provides the equivalent of
1748 the new "info exceptions" command.
1750 * New system-wide configuration scripts
1751 A GDB installation now provides scripts suitable for use as system-wide
1752 configuration scripts for the following systems:
1756 * GDB now supports target-assigned range stepping with remote targets.
1757 This improves the performance of stepping source lines by reducing
1758 the number of control packets from/to GDB. See "New remote packets"
1761 * GDB now understands the element 'tvar' in the XML traceframe info.
1762 It has the id of the collected trace state variables.
1764 * On S/390 targets that provide the transactional-execution feature,
1765 the program interruption transaction diagnostic block (TDB) is now
1766 represented as a number of additional "registers" in GDB.
1768 * New remote packets
1772 The vCont packet supports a new 'r' action, that tells the remote
1773 stub to step through an address range itself, without GDB
1774 involvemement at each single-step.
1776 qXfer:libraries-svr4:read's annex
1777 The previously unused annex of the qXfer:libraries-svr4:read packet
1778 is now used to support passing an argument list. The remote stub
1779 reports support for this argument list to GDB's qSupported query.
1780 The defined arguments are "start" and "prev", used to reduce work
1781 necessary for library list updating, resulting in significant
1784 * New features in the GDB remote stub, GDBserver
1786 ** GDBserver now supports target-assisted range stepping. Currently
1787 enabled on x86/x86_64 GNU/Linux targets.
1789 ** GDBserver now adds element 'tvar' in the XML in the reply to
1790 'qXfer:traceframe-info:read'. It has the id of the collected
1791 trace state variables.
1793 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1796 * New 'z' formatter for printing and examining memory, this displays the
1797 value as hexadecimal zero padded on the left to the size of the type.
1799 * GDB can now use Windows x64 unwinding data.
1801 * The "set remotebaud" command has been replaced by "set serial baud".
1802 Similarly, "show remotebaud" has been replaced by "show serial baud".
1803 The "set remotebaud" and "show remotebaud" commands are still available
1804 to provide backward compatibility with older versions of GDB.
1806 *** Changes in GDB 7.6
1808 * Target record has been renamed to record-full.
1809 Record/replay is now enabled with the "record full" command.
1810 This also affects settings that are associated with full record/replay
1811 that have been moved from "set/show record" to "set/show record full":
1813 set|show record full insn-number-max
1814 set|show record full stop-at-limit
1815 set|show record full memory-query
1817 * A new record target "record-btrace" has been added. The new target
1818 uses hardware support to record the control-flow of a process. It
1819 does not support replaying the execution, but it implements the
1820 below new commands for investigating the recorded execution log.
1821 This new recording method can be enabled using:
1825 The "record-btrace" target is only available on Intel Atom processors
1826 and requires a Linux kernel 2.6.32 or later.
1828 * Two new commands have been added for record/replay to give information
1829 about the recorded execution without having to replay the execution.
1830 The commands are only supported by "record btrace".
1832 record instruction-history prints the execution history at
1833 instruction granularity
1835 record function-call-history prints the execution history at
1836 function granularity
1838 * New native configurations
1840 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1841 FreeBSD/powerpc powerpc*-*-freebsd
1842 x86_64/Cygwin x86_64-*-cygwin*
1843 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1847 ARM AArch64 aarch64*-*-elf
1848 ARM AArch64 GNU/Linux aarch64*-*-linux
1849 Lynx 178 PowerPC powerpc-*-lynx*178
1850 x86_64/Cygwin x86_64-*-cygwin*
1851 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1853 * If the configured location of system.gdbinit file (as given by the
1854 --with-system-gdbinit option at configure time) is in the
1855 data-directory (as specified by --with-gdb-datadir at configure
1856 time) or in one of its subdirectories, then GDB will look for the
1857 system-wide init file in the directory specified by the
1858 --data-directory command-line option.
1860 * New command line options:
1862 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1863 other initialization files, unlike -nx which disables all of them.
1865 * Removed command line options
1867 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1870 * The 'ptype' and 'whatis' commands now accept an argument to control
1873 * 'info proc' now works on some core files.
1877 ** Vectors can be created with gdb.Type.vector.
1879 ** Python's atexit.register now works in GDB.
1881 ** Types can be pretty-printed via a Python API.
1883 ** Python 3 is now supported (in addition to Python 2.4 or later)
1885 ** New class gdb.Architecture exposes GDB's internal representation
1886 of architecture in the Python API.
1888 ** New method Frame.architecture returns the gdb.Architecture object
1889 corresponding to the frame's architecture.
1891 * New Python-based convenience functions:
1893 ** $_memeq(buf1, buf2, length)
1894 ** $_streq(str1, str2)
1896 ** $_regex(str, regex)
1898 * The 'cd' command now defaults to using '~' (the home directory) if not
1901 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
1902 default for GCC since November 2000.
1904 * The command 'forward-search' can now be abbreviated as 'fo'.
1906 * The command 'info tracepoints' can now display 'installed on target'
1907 or 'not installed on target' for each non-pending location of tracepoint.
1909 * New configure options
1911 --enable-libmcheck/--disable-libmcheck
1912 By default, development versions are built with -lmcheck on hosts
1913 that support it, in order to help track memory corruption issues.
1914 Release versions, on the other hand, are built without -lmcheck
1915 by default. The --enable-libmcheck/--disable-libmcheck configure
1916 options allow the user to override that default.
1917 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
1918 This configure option allows the user to build GDB with
1919 libbabeltrace using which GDB can read Common Trace Format data.
1921 * New commands (for set/show, see "New options" below)
1924 Catch signals. This is similar to "handle", but allows commands and
1925 conditions to be attached.
1928 List the BFDs known to GDB.
1930 python-interactive [command]
1932 Start a Python interactive prompt, or evaluate the optional command
1933 and print the result of expressions.
1936 "py" is a new alias for "python".
1938 enable type-printer [name]...
1939 disable type-printer [name]...
1940 Enable or disable type printers.
1944 ** For the Renesas Super-H architecture, the "regs" command has been removed
1945 (has been deprecated in GDB 7.5), and "info all-registers" should be used
1950 set print type methods (on|off)
1951 show print type methods
1952 Control whether method declarations are displayed by "ptype".
1953 The default is to show them.
1955 set print type typedefs (on|off)
1956 show print type typedefs
1957 Control whether typedef definitions are displayed by "ptype".
1958 The default is to show them.
1960 set filename-display basename|relative|absolute
1961 show filename-display
1962 Control the way in which filenames is displayed.
1963 The default is "relative", which preserves previous behavior.
1965 set trace-buffer-size
1966 show trace-buffer-size
1967 Request target to change the size of trace buffer.
1969 set remote trace-buffer-size-packet auto|on|off
1970 show remote trace-buffer-size-packet
1971 Control the use of the remote protocol `QTBuffer:size' packet.
1975 Control display of debugging messages related to ARM AArch64.
1978 set debug coff-pe-read
1979 show debug coff-pe-read
1980 Control display of debugging messages related to reading of COFF/PE
1985 Control display of debugging messages related to Mach-O symbols
1988 set debug notification
1989 show debug notification
1990 Control display of debugging info for async remote notification.
1994 ** Command parameter changes are now notified using new async record
1995 "=cmd-param-changed".
1996 ** Trace frame changes caused by command "tfind" are now notified using
1997 new async record "=traceframe-changed".
1998 ** The creation, deletion and modification of trace state variables
1999 are now notified using new async records "=tsv-created",
2000 "=tsv-deleted" and "=tsv-modified".
2001 ** The start and stop of process record are now notified using new
2002 async record "=record-started" and "=record-stopped".
2003 ** Memory changes are now notified using new async record
2005 ** The data-disassemble command response will include a "fullname" field
2006 containing the absolute file name when source has been requested.
2007 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2008 command, to allow pattern filling of memory areas.
2009 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2010 library load/unload events.
2011 ** The response to breakpoint commands and breakpoint async records
2012 includes an "installed" field containing a boolean state about each
2013 non-pending tracepoint location is whether installed on target or not.
2014 ** Output of the "-trace-status" command includes a "trace-file" field
2015 containing the name of the trace file being examined. This field is
2016 optional, and only present when examining a trace file.
2017 ** The "fullname" field is now always present along with the "file" field,
2018 even if the file cannot be found by GDB.
2020 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2021 You must have the LZMA library available when configuring GDB for this
2022 feature to be enabled. For more information, see:
2023 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2025 * New remote packets
2028 Set the size of trace buffer. The remote stub reports support for this
2029 packet to gdb's qSupported query.
2032 Enable Branch Trace Store (BTS)-based branch tracing for the current
2033 thread. The remote stub reports support for this packet to gdb's
2037 Disable branch tracing for the current thread. The remote stub reports
2038 support for this packet to gdb's qSupported query.
2041 Read the traced branches for the current thread. The remote stub
2042 reports support for this packet to gdb's qSupported query.
2044 *** Changes in GDB 7.5
2046 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2047 for more x32 ABI info.
2049 * GDB now supports access to MIPS DSP registers on Linux targets.
2051 * GDB now supports debugging microMIPS binaries.
2053 * The "info os" command on GNU/Linux can now display information on
2054 several new classes of objects managed by the operating system:
2055 "info os procgroups" lists process groups
2056 "info os files" lists file descriptors
2057 "info os sockets" lists internet-domain sockets
2058 "info os shm" lists shared-memory regions
2059 "info os semaphores" lists semaphores
2060 "info os msg" lists message queues
2061 "info os modules" lists loaded kernel modules
2063 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2064 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2065 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2066 options and inspect the probe arguments using the new $_probe_arg family
2067 of convenience variables. You can obtain more information about SystemTap
2068 in <http://sourceware.org/systemtap/>.
2070 * GDB now supports reversible debugging on ARM, it allows you to
2071 debug basic ARM and THUMB instructions, and provides
2072 record/replay support.
2074 * The option "symbol-reloading" has been deleted as it is no longer used.
2078 ** GDB commands implemented in Python can now be put in command class
2081 ** The "maint set python print-stack on|off" is now deleted.
2083 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2084 apply "flag enum"-style pretty-printing to any enum.
2086 ** gdb.lookup_symbol can now work when there is no current frame.
2088 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2089 the source at which the symbol was defined.
2091 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2092 method 'value'. The former indicates whether the symbol needs a
2093 frame in order to compute its value, and the latter computes the
2096 ** A new method 'referenced_value' on gdb.Value objects which can
2097 dereference pointer as well as C++ reference values.
2099 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2100 which return the global and static blocks (as gdb.Block objects),
2101 of the underlying symbol table, respectively.
2103 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2104 object associated with a PC value.
2106 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2107 of the address range occupied by code for the current source line.
2109 * Go language support.
2110 GDB now supports debugging programs written in the Go programming
2113 * GDBserver now supports stdio connections.
2114 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2116 * The binary "gdbtui" can no longer be built or installed.
2117 Use "gdb -tui" instead.
2119 * GDB will now print "flag" enums specially. A flag enum is one where
2120 all the enumerator values have no bits in common when pairwise
2121 "and"ed. When printing a value whose type is a flag enum, GDB will
2122 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2123 (gdb) print (enum E) 3
2126 * The filename part of a linespec will now match trailing components
2127 of a source file name. For example, "break gcc/expr.c:1000" will
2128 now set a breakpoint in build/gcc/expr.c, but not
2129 build/libcpp/expr.c.
2131 * The "info proc" and "generate-core-file" commands will now also
2132 work on remote targets connected to GDBserver on Linux.
2134 * The command "info catch" has been removed. It has been disabled
2135 since December 2007.
2137 * The "catch exception" and "catch assert" commands now accept
2138 a condition at the end of the command, much like the "break"
2139 command does. For instance:
2141 (gdb) catch exception Constraint_Error if Barrier = True
2143 Previously, it was possible to add a condition to such catchpoints,
2144 but it had to be done as a second step, after the catchpoint had been
2145 created, using the "condition" command.
2147 * The "info static-tracepoint-marker" command will now also work on
2148 native Linux targets with in-process agent.
2150 * GDB can now set breakpoints on inlined functions.
2152 * The .gdb_index section has been updated to include symbols for
2153 inlined functions. GDB will ignore older .gdb_index sections by
2154 default, which could cause symbol files to be loaded more slowly
2155 until their .gdb_index sections can be recreated. The new command
2156 "set use-deprecated-index-sections on" will cause GDB to use any older
2157 .gdb_index sections it finds. This will restore performance, but the
2158 ability to set breakpoints on inlined functions will be lost in symbol
2159 files with older .gdb_index sections.
2161 The .gdb_index section has also been updated to record more information
2162 about each symbol. This speeds up the "info variables", "info functions"
2163 and "info types" commands when used with programs having the .gdb_index
2164 section, as well as speeding up debugging with shared libraries using
2165 the .gdb_index section.
2167 * Ada support for GDB/MI Variable Objects has been added.
2169 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2174 ** New command -info-os is the MI equivalent of "info os".
2176 ** Output logs ("set logging" and related) now include MI output.
2180 ** "set use-deprecated-index-sections on|off"
2181 "show use-deprecated-index-sections on|off"
2182 Controls the use of deprecated .gdb_index sections.
2184 ** "catch load" and "catch unload" can be used to stop when a shared
2185 library is loaded or unloaded, respectively.
2187 ** "enable count" can be used to auto-disable a breakpoint after
2190 ** "info vtbl" can be used to show the virtual method tables for
2191 C++ and Java objects.
2193 ** "explore" and its sub commands "explore value" and "explore type"
2194 can be used to recursively explore values and types of
2195 expressions. These commands are available only if GDB is
2196 configured with '--with-python'.
2198 ** "info auto-load" shows status of all kinds of auto-loaded files,
2199 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2200 sequences of commands files, "info auto-load python-scripts"
2201 shows status of auto-loading Python script files,
2202 "info auto-load local-gdbinit" shows status of loading init file
2203 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2204 status of inferior specific thread debugging shared library loading.
2206 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2207 and "show auto-load-scripts" commands have been deprecated, use their
2208 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2209 and "show auto-load python-scripts" counterparts instead.
2211 ** "dprintf location,format,args..." creates a dynamic printf, which
2212 is basically a breakpoint that does a printf and immediately
2213 resumes your program's execution, so it is like a printf that you
2214 can insert dynamically at runtime instead of at compiletime.
2216 ** "set print symbol"
2218 Controls whether GDB attempts to display the symbol, if any,
2219 corresponding to addresses it prints. This defaults to "on", but
2220 you can set it to "off" to restore GDB's previous behavior.
2222 * Deprecated commands
2224 ** For the Renesas Super-H architecture, the "regs" command has been
2225 deprecated, and "info all-registers" should be used instead.
2229 Renesas RL78 rl78-*-elf
2230 HP OpenVMS ia64 ia64-hp-openvms*
2232 * GDBserver supports evaluation of breakpoint conditions. When
2233 support is advertised by GDBserver, GDB may be told to send the
2234 breakpoint conditions in bytecode form to GDBserver. GDBserver
2235 will only report the breakpoint trigger to GDB when its condition
2240 set mips compression
2241 show mips compression
2242 Select the compressed ISA encoding used in functions that have no symbol
2243 information available. The encoding can be set to either of:
2246 and is updated automatically from ELF file flags if available.
2248 set breakpoint condition-evaluation
2249 show breakpoint condition-evaluation
2250 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2251 GDBserver ("target"). Default option "auto" chooses the most efficient
2253 This option can improve debugger efficiency depending on the speed of the
2257 Disable auto-loading globally.
2260 Show auto-loading setting of all kinds of auto-loaded files.
2262 set auto-load gdb-scripts on|off
2263 show auto-load gdb-scripts
2264 Control auto-loading of GDB canned sequences of commands files.
2266 set auto-load python-scripts on|off
2267 show auto-load python-scripts
2268 Control auto-loading of Python script files.
2270 set auto-load local-gdbinit on|off
2271 show auto-load local-gdbinit
2272 Control loading of init file (.gdbinit) from current directory.
2274 set auto-load libthread-db on|off
2275 show auto-load libthread-db
2276 Control auto-loading of inferior specific thread debugging shared library.
2278 set auto-load scripts-directory <dir1>[:<dir2>...]
2279 show auto-load scripts-directory
2280 Set a list of directories from which to load auto-loaded scripts.
2281 Automatically loaded Python scripts and GDB scripts are located in one
2282 of the directories listed by this option.
2283 The delimiter (':' above) may differ according to the host platform.
2285 set auto-load safe-path <dir1>[:<dir2>...]
2286 show auto-load safe-path
2287 Set a list of directories from which it is safe to auto-load files.
2288 The delimiter (':' above) may differ according to the host platform.
2290 set debug auto-load on|off
2291 show debug auto-load
2292 Control display of debugging info for auto-loading the files above.
2294 set dprintf-style gdb|call|agent
2296 Control the way in which a dynamic printf is performed; "gdb"
2297 requests a GDB printf command, while "call" causes dprintf to call a
2298 function in the inferior. "agent" requests that the target agent
2299 (such as GDBserver) do the printing.
2301 set dprintf-function <expr>
2302 show dprintf-function
2303 set dprintf-channel <expr>
2304 show dprintf-channel
2305 Set the function and optional first argument to the call when using
2306 the "call" style of dynamic printf.
2308 set disconnected-dprintf on|off
2309 show disconnected-dprintf
2310 Control whether agent-style dynamic printfs continue to be in effect
2311 after GDB disconnects.
2313 * New configure options
2315 --with-auto-load-dir
2316 Configure default value for the 'set auto-load scripts-directory'
2317 setting above. It defaults to '$debugdir:$datadir/auto-load',
2318 $debugdir representing global debugging info directories (available
2319 via 'show debug-file-directory') and $datadir representing GDB's data
2320 directory (available via 'show data-directory').
2322 --with-auto-load-safe-path
2323 Configure default value for the 'set auto-load safe-path' setting
2324 above. It defaults to the --with-auto-load-dir setting.
2326 --without-auto-load-safe-path
2327 Set 'set auto-load safe-path' to '/', effectively disabling this
2330 * New remote packets
2332 z0/z1 conditional breakpoints extension
2334 The z0/z1 breakpoint insertion packets have been extended to carry
2335 a list of conditional expressions over to the remote stub depending on the
2336 condition evaluation mode. The use of this extension can be controlled
2337 via the "set remote conditional-breakpoints-packet" command.
2341 Specify the signals which the remote stub may pass to the debugged
2342 program without GDB involvement.
2344 * New command line options
2346 --init-command=FILE, -ix Like --command, -x but execute it
2347 before loading inferior.
2348 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2349 execute it before loading inferior.
2351 *** Changes in GDB 7.4
2353 * GDB now handles ambiguous linespecs more consistently; the existing
2354 FILE:LINE support has been expanded to other types of linespecs. A
2355 breakpoint will now be set on all matching locations in all
2356 inferiors, and locations will be added or removed according to
2359 * GDB now allows you to skip uninteresting functions and files when
2360 stepping with the "skip function" and "skip file" commands.
2362 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2363 and "show remote hardware-watchpoint-length-limit". These allows to
2364 set or show the maximum length limit (in bytes) of a remote
2365 target hardware watchpoint.
2367 This allows e.g. to use "unlimited" hardware watchpoints with the
2368 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2369 watchpoints are slower than real hardware watchpoints but are
2370 significantly faster than gdb software watchpoints.
2374 ** The register_pretty_printer function in module gdb.printing now takes
2375 an optional `replace' argument. If True, the new printer replaces any
2378 ** The "maint set python print-stack on|off" command has been
2379 deprecated and will be deleted in GDB 7.5.
2380 A new command: "set python print-stack none|full|message" has
2381 replaced it. Additionally, the default for "print-stack" is
2382 now "message", which just prints the error message without
2385 ** A prompt substitution hook (prompt_hook) is now available to the
2388 ** A new Python module, gdb.prompt has been added to the GDB Python
2389 modules library. This module provides functionality for
2390 escape sequences in prompts (used by set/show
2391 extended-prompt). These escape sequences are replaced by their
2392 corresponding value.
2394 ** Python commands and convenience-functions located in
2395 'data-directory'/python/gdb/command and
2396 'data-directory'/python/gdb/function are now automatically loaded
2399 ** Blocks now provide four new attributes. global_block and
2400 static_block will return the global and static blocks
2401 respectively. is_static and is_global are boolean attributes
2402 that indicate if the block is one of those two types.
2404 ** Symbols now provide the "type" attribute, the type of the symbol.
2406 ** The "gdb.breakpoint" function has been deprecated in favor of
2409 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2410 of a function. This class is based on the "finish" command
2411 available in the CLI.
2413 ** Type objects for struct and union types now allow access to
2414 the fields using standard Python dictionary (mapping) methods.
2415 For example, "some_type['myfield']" now works, as does
2416 "some_type.items()".
2418 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2421 ** A new function, "deep_items" has been added to the gdb.types
2422 module in the GDB Python modules library. This function returns
2423 an iterator over the fields of a struct or union type. Unlike
2424 the standard Python "iteritems" method, it will recursively traverse
2425 any anonymous fields.
2429 ** "*stopped" events can report several new "reason"s, such as
2432 ** Breakpoint changes are now notified using new async records, like
2433 "=breakpoint-modified".
2435 ** New command -ada-task-info.
2437 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2438 $sdir specifies the default system locations of shared libraries.
2439 $pdir specifies the directory where the libpthread used by the application
2442 GDB no longer looks in $sdir and $pdir after it has searched the directories
2443 mentioned in libthread-db-search-path. If you want to search those
2444 directories, they must be specified in libthread-db-search-path.
2445 The default value of libthread-db-search-path on GNU/Linux and Solaris
2446 systems is now "$sdir:$pdir".
2448 $pdir is not supported by gdbserver, it is currently ignored.
2449 $sdir is supported by gdbserver.
2451 * New configure option --with-iconv-bin.
2452 When using the internationalization support like the one in the GNU C
2453 library, GDB will invoke the "iconv" program to get a list of supported
2454 character sets. If this program lives in a non-standard location, one can
2455 use this option to specify where to find it.
2457 * When natively debugging programs on PowerPC BookE processors running
2458 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2459 watchpoints, which specify a mask in addition to an address to watch.
2460 The mask specifies that some bits of an address (the bits which are
2461 reset in the mask) should be ignored when matching the address accessed
2462 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2463 section in the user manual for more details.
2465 * The new option --once causes GDBserver to stop listening for connections once
2466 the first connection is made. The listening port used by GDBserver will
2467 become available after that.
2469 * New commands "info macros" and "alias" have been added.
2471 * New function parameters suffix @entry specifies value of function parameter
2472 at the time the function got called. Entry values are available only since
2478 "!" is now an alias of the "shell" command.
2479 Note that no space is needed between "!" and SHELL COMMAND.
2483 watch EXPRESSION mask MASK_VALUE
2484 The watch command now supports the mask argument which allows creation
2485 of masked watchpoints, if the current architecture supports this feature.
2487 info auto-load-scripts [REGEXP]
2488 This command was formerly named "maintenance print section-scripts".
2489 It is now generally useful and is no longer a maintenance-only command.
2491 info macro [-all] [--] MACRO
2492 The info macro command has new options `-all' and `--'. The first for
2493 printing all definitions of a macro. The second for explicitly specifying
2494 the end of arguments and the beginning of the macro name in case the macro
2495 name starts with a hyphen.
2497 collect[/s] EXPRESSIONS
2498 The tracepoint collect command now takes an optional modifier "/s"
2499 that directs it to dereference pointer-to-character types and
2500 collect the bytes of memory up to a zero byte. The behavior is
2501 similar to what you see when you use the regular print command on a
2502 string. An optional integer following the "/s" sets a bound on the
2503 number of bytes that will be collected.
2506 The trace start command now interprets any supplied arguments as a
2507 note to be recorded with the trace run, with an effect similar to
2508 setting the variable trace-notes.
2511 The trace stop command now interprets any arguments as a note to be
2512 mentioned along with the tstatus report that the trace was stopped
2513 with a command. The effect is similar to setting the variable
2516 * Tracepoints can now be enabled and disabled at any time after a trace
2517 experiment has been started using the standard "enable" and "disable"
2518 commands. It is now possible to start a trace experiment with no enabled
2519 tracepoints; GDB will display a warning, but will allow the experiment to
2520 begin, assuming that tracepoints will be enabled as needed while the trace
2523 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2524 locations with 4-byte instructions, when they were previously
2525 limited to locations with instructions of 5 bytes or longer.
2529 set debug dwarf2-read
2530 show debug dwarf2-read
2531 Turns on or off display of debugging messages related to reading
2532 DWARF debug info. The default is off.
2534 set debug symtab-create
2535 show debug symtab-create
2536 Turns on or off display of debugging messages related to symbol table
2537 creation. The default is off.
2540 show extended-prompt
2541 Set the GDB prompt, and allow escape sequences to be inserted to
2542 display miscellaneous information (see 'help set extended-prompt'
2543 for the list of sequences). This prompt (and any information
2544 accessed through the escape sequences) is updated every time the
2545 prompt is displayed.
2547 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2548 show print entry-values
2549 Set printing of frame argument values at function entry. In some cases
2550 GDB can determine the value of function argument which was passed by the
2551 function caller, even if the value was modified inside the called function.
2553 set debug entry-values
2554 show debug entry-values
2555 Control display of debugging info for determining frame argument values at
2556 function entry and virtual tail call frames.
2558 set basenames-may-differ
2559 show basenames-may-differ
2560 Set whether a source file may have multiple base names.
2561 (A "base name" is the name of a file with the directory part removed.
2562 Example: The base name of "/home/user/hello.c" is "hello.c".)
2563 If set, GDB will canonicalize file names (e.g., expand symlinks)
2564 before comparing them. Canonicalization is an expensive operation,
2565 but it allows the same file be known by more than one base name.
2566 If not set (the default), all source files are assumed to have just
2567 one base name, and gdb will do file name comparisons more efficiently.
2573 Set a user name and notes for the current and any future trace runs.
2574 This is useful for long-running and/or disconnected traces, to
2575 inform others (or yourself) as to who is running the trace, supply
2576 contact information, or otherwise explain what is going on.
2578 set trace-stop-notes
2579 show trace-stop-notes
2580 Set a note attached to the trace run, that is displayed when the
2581 trace has been stopped by a tstop command. This is useful for
2582 instance as an explanation, if you are stopping a trace run that was
2583 started by someone else.
2585 * New remote packets
2589 Dynamically enable a tracepoint in a started trace experiment.
2593 Dynamically disable a tracepoint in a started trace experiment.
2597 Set the user and notes of the trace run.
2601 Query the current status of a tracepoint.
2605 Query the minimum length of instruction at which a fast tracepoint may
2608 * Dcache size (number of lines) and line-size are now runtime-configurable
2609 via "set dcache line" and "set dcache line-size" commands.
2613 Texas Instruments TMS320C6x tic6x-*-*
2617 Renesas RL78 rl78-*-elf
2619 *** Changes in GDB 7.3.1
2621 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2623 *** Changes in GDB 7.3
2625 * GDB has a new command: "thread find [REGEXP]".
2626 It finds the thread id whose name, target id, or thread extra info
2627 matches the given regular expression.
2629 * The "catch syscall" command now works on mips*-linux* targets.
2631 * The -data-disassemble MI command now supports modes 2 and 3 for
2632 dumping the instruction opcodes.
2634 * New command line options
2636 -data-directory DIR Specify DIR as the "data-directory".
2637 This is mostly for testing purposes.
2639 * The "maint set python auto-load on|off" command has been renamed to
2640 "set auto-load-scripts on|off".
2642 * GDB has a new command: "set directories".
2643 It is like the "dir" command except that it replaces the
2644 source path list instead of augmenting it.
2646 * GDB now understands thread names.
2648 On GNU/Linux, "info threads" will display the thread name as set by
2649 prctl or pthread_setname_np.
2651 There is also a new command, "thread name", which can be used to
2652 assign a name internally for GDB to display.
2655 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2656 has been integrated into GDB.
2660 ** The function gdb.Write now accepts an optional keyword 'stream'.
2661 This keyword, when provided, will direct the output to either
2662 stdout, stderr, or GDB's logging output.
2664 ** Parameters can now be be sub-classed in Python, and in particular
2665 you may implement the get_set_doc and get_show_doc functions.
2666 This improves how Parameter set/show documentation is processed
2667 and allows for more dynamic content.
2669 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2670 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2671 have an is_valid method.
2673 ** Breakpoints can now be sub-classed in Python, and in particular
2674 you may implement a 'stop' function that is executed each time
2675 the inferior reaches that breakpoint.
2677 ** New function gdb.lookup_global_symbol looks up a global symbol.
2679 ** GDB values in Python are now callable if the value represents a
2680 function. For example, if 'some_value' represents a function that
2681 takes two integer parameters and returns a value, you can call
2682 that function like so:
2684 result = some_value (10,20)
2686 ** Module gdb.types has been added.
2687 It contains a collection of utilities for working with gdb.Types objects:
2688 get_basic_type, has_field, make_enum_dict.
2690 ** Module gdb.printing has been added.
2691 It contains utilities for writing and registering pretty-printers.
2692 New classes: PrettyPrinter, SubPrettyPrinter,
2693 RegexpCollectionPrettyPrinter.
2694 New function: register_pretty_printer.
2696 ** New commands "info pretty-printers", "enable pretty-printer" and
2697 "disable pretty-printer" have been added.
2699 ** gdb.parameter("directories") is now available.
2701 ** New function gdb.newest_frame returns the newest frame in the
2704 ** The gdb.InferiorThread class has a new "name" attribute. This
2705 holds the thread's name.
2707 ** Python Support for Inferior events.
2708 Python scripts can add observers to be notified of events
2709 occurring in the process being debugged.
2710 The following events are currently supported:
2711 - gdb.events.cont Continue event.
2712 - gdb.events.exited Inferior exited event.
2713 - gdb.events.stop Signal received, and Breakpoint hit events.
2717 ** GDB now puts template parameters in scope when debugging in an
2718 instantiation. For example, if you have:
2720 template<int X> int func (void) { return X; }
2722 then if you step into func<5>, "print X" will show "5". This
2723 feature requires proper debuginfo support from the compiler; it
2724 was added to GCC 4.5.
2726 ** The motion commands "next", "finish", "until", and "advance" now
2727 work better when exceptions are thrown. In particular, GDB will
2728 no longer lose control of the inferior; instead, the GDB will
2729 stop the inferior at the point at which the exception is caught.
2730 This functionality requires a change in the exception handling
2731 code that was introduced in GCC 4.5.
2733 * GDB now follows GCC's rules on accessing volatile objects when
2734 reading or writing target state during expression evaluation.
2735 One notable difference to prior behavior is that "print x = 0"
2736 no longer generates a read of x; the value of the assignment is
2737 now always taken directly from the value being assigned.
2739 * GDB now has some support for using labels in the program's source in
2740 linespecs. For instance, you can use "advance label" to continue
2741 execution to a label.
2743 * GDB now has support for reading and writing a new .gdb_index
2744 section. This section holds a fast index of DWARF debugging
2745 information and can be used to greatly speed up GDB startup and
2746 operation. See the documentation for `save gdb-index' for details.
2748 * The "watch" command now accepts an optional "-location" argument.
2749 When used, this causes GDB to watch the memory referred to by the
2750 expression. Such a watchpoint is never deleted due to it going out
2753 * GDB now supports thread debugging of core dumps on GNU/Linux.
2755 GDB now activates thread debugging using the libthread_db library
2756 when debugging GNU/Linux core dumps, similarly to when debugging
2757 live processes. As a result, when debugging a core dump file, GDB
2758 is now able to display pthread_t ids of threads. For example, "info
2759 threads" shows the same output as when debugging the process when it
2760 was live. In earlier releases, you'd see something like this:
2763 * 1 LWP 6780 main () at main.c:10
2765 While now you see this:
2768 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2770 It is also now possible to inspect TLS variables when debugging core
2773 When debugging a core dump generated on a machine other than the one
2774 used to run GDB, you may need to point GDB at the correct
2775 libthread_db library with the "set libthread-db-search-path"
2776 command. See the user manual for more details on this command.
2778 * When natively debugging programs on PowerPC BookE processors running
2779 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2780 which stop execution of the inferior whenever it executes an instruction
2781 at any address within the specified range. See the "PowerPC Embedded"
2782 section in the user manual for more details.
2784 * New features in the GDB remote stub, GDBserver
2786 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2787 and i686 LynxOS (version 5.x).
2789 ** GDBserver is now supported on Blackfin Linux.
2791 * New native configurations
2793 ia64 HP-UX ia64-*-hpux*
2797 Analog Devices, Inc. Blackfin Processor bfin-*
2799 * Ada task switching is now supported on sparc-elf targets when
2800 debugging a program using the Ravenscar Profile. For more information,
2801 see the "Tasking Support when using the Ravenscar Profile" section
2802 in the GDB user manual.
2804 * Guile support was removed.
2806 * New features in the GNU simulator
2808 ** The --map-info flag lists all known core mappings.
2810 ** CFI flashes may be simulated via the "cfi" device.
2812 *** Changes in GDB 7.2
2814 * Shared library support for remote targets by default
2816 When GDB is configured for a generic, non-OS specific target, like
2817 for example, --target=arm-eabi or one of the many *-*-elf targets,
2818 GDB now queries remote stubs for loaded shared libraries using the
2819 `qXfer:libraries:read' packet. Previously, shared library support
2820 was always disabled for such configurations.
2824 ** Argument Dependent Lookup (ADL)
2826 In C++ ADL lookup directs function search to the namespaces of its
2827 arguments even if the namespace has not been imported.
2837 Here the compiler will search for `foo' in the namespace of 'b'
2838 and find A::foo. GDB now supports this. This construct is commonly
2839 used in the Standard Template Library for operators.
2841 ** Improved User Defined Operator Support
2843 In addition to member operators, GDB now supports lookup of operators
2844 defined in a namespace and imported with a `using' directive, operators
2845 defined in the global scope, operators imported implicitly from an
2846 anonymous namespace, and the ADL operators mentioned in the previous
2848 GDB now also supports proper overload resolution for all the previously
2849 mentioned flavors of operators.
2851 ** static const class members
2853 Printing of static const class members that are initialized in the
2854 class definition has been fixed.
2856 * Windows Thread Information Block access.
2858 On Windows targets, GDB now supports displaying the Windows Thread
2859 Information Block (TIB) structure. This structure is visible either
2860 by using the new command `info w32 thread-information-block' or, by
2861 dereferencing the new convenience variable named `$_tlb', a
2862 thread-specific pointer to the TIB. This feature is also supported
2863 when remote debugging using GDBserver.
2865 * Static tracepoints
2867 Static tracepoints are calls in the user program into a tracing
2868 library. One such library is a port of the LTTng kernel tracer to
2869 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2870 When debugging with GDBserver, GDB now supports combining the GDB
2871 tracepoint machinery with such libraries. For example: the user can
2872 use GDB to probe a static tracepoint marker (a call from the user
2873 program into the tracing library) with the new "strace" command (see
2874 "New commands" below). This creates a "static tracepoint" in the
2875 breakpoint list, that can be manipulated with the same feature set
2876 as fast and regular tracepoints. E.g., collect registers, local and
2877 global variables, collect trace state variables, and define
2878 tracepoint conditions. In addition, the user can collect extra
2879 static tracepoint marker specific data, by collecting the new
2880 $_sdata internal variable. When analyzing the trace buffer, you can
2881 inspect $_sdata like any other variable available to GDB. For more
2882 information, see the "Tracepoints" chapter in GDB user manual. New
2883 remote packets have been defined to support static tracepoints, see
2884 the "New remote packets" section below.
2886 * Better reconstruction of tracepoints after disconnected tracing
2888 GDB will attempt to download the original source form of tracepoint
2889 definitions when starting a trace run, and then will upload these
2890 upon reconnection to the target, resulting in a more accurate
2891 reconstruction of the tracepoints that are in use on the target.
2895 You can now exercise direct control over the ways that GDB can
2896 affect your program. For instance, you can disallow the setting of
2897 breakpoints, so that the program can run continuously (assuming
2898 non-stop mode). In addition, the "observer" variable is available
2899 to switch all of the different controls; in observer mode, GDB
2900 cannot affect the target's behavior at all, which is useful for
2901 tasks like diagnosing live systems in the field.
2903 * The new convenience variable $_thread holds the number of the
2906 * New remote packets
2910 Return the address of the Windows Thread Information Block of a given thread.
2914 In response to several of the tracepoint packets, the target may now
2915 also respond with a number of intermediate `qRelocInsn' request
2916 packets before the final result packet, to have GDB handle
2917 relocating an instruction to execute at a different address. This
2918 is particularly useful for stubs that support fast tracepoints. GDB
2919 reports support for this feature in the qSupported packet.
2923 List static tracepoint markers in the target program.
2927 List static tracepoint markers at a given address in the target
2930 qXfer:statictrace:read
2932 Read the static trace data collected (by a `collect $_sdata'
2933 tracepoint action). The remote stub reports support for this packet
2934 to gdb's qSupported query.
2938 Send the current settings of GDB's permission flags.
2942 Send part of the source (textual) form of a tracepoint definition,
2943 which includes location, conditional, and action list.
2945 * The source command now accepts a -s option to force searching for the
2946 script in the source search path even if the script name specifies
2949 * New features in the GDB remote stub, GDBserver
2951 - GDBserver now support tracepoints (including fast tracepoints, and
2952 static tracepoints). The feature is currently supported by the
2953 i386-linux and amd64-linux builds. See the "Tracepoints support
2954 in gdbserver" section in the manual for more information.
2956 GDBserver JIT compiles the tracepoint's conditional agent
2957 expression bytecode into native code whenever possible for low
2958 overhead dynamic tracepoints conditionals. For such tracepoints,
2959 an expression that examines program state is evaluated when the
2960 tracepoint is reached, in order to determine whether to capture
2961 trace data. If the condition is simple and false, processing the
2962 tracepoint finishes very quickly and no data is gathered.
2964 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
2965 for static tracepoints support.
2967 - GDBserver now supports x86_64 Windows 64-bit debugging.
2969 * GDB now sends xmlRegisters= in qSupported packet to indicate that
2970 it understands register description.
2972 * The --batch flag now disables pagination and queries.
2974 * X86 general purpose registers
2976 GDB now supports reading/writing byte, word and double-word x86
2977 general purpose registers directly. This means you can use, say,
2978 $ah or $ax to refer, respectively, to the byte register AH and
2979 16-bit word register AX that are actually portions of the 32-bit
2980 register EAX or 64-bit register RAX.
2982 * The `commands' command now accepts a range of breakpoints to modify.
2983 A plain `commands' following a command that creates multiple
2984 breakpoints affects all the breakpoints set by that command. This
2985 applies to breakpoints set by `rbreak', and also applies when a
2986 single `break' command creates multiple breakpoints (e.g.,
2987 breakpoints on overloaded c++ functions).
2989 * The `rbreak' command now accepts a filename specification as part of
2990 its argument, limiting the functions selected by the regex to those
2991 in the specified file.
2993 * Support for remote debugging Windows and SymbianOS shared libraries
2994 from Unix hosts has been improved. Non Windows GDB builds now can
2995 understand target reported file names that follow MS-DOS based file
2996 system semantics, such as file names that include drive letters and
2997 use the backslash character as directory separator. This makes it
2998 possible to transparently use the "set sysroot" and "set
2999 solib-search-path" on Unix hosts to point as host copies of the
3000 target's shared libraries. See the new command "set
3001 target-file-system-kind" described below, and the "Commands to
3002 specify files" section in the user manual for more information.
3006 eval template, expressions...
3007 Convert the values of one or more expressions under the control
3008 of the string template to a command line, and call it.
3010 set target-file-system-kind unix|dos-based|auto
3011 show target-file-system-kind
3012 Set or show the assumed file system kind for target reported file
3015 save breakpoints <filename>
3016 Save all current breakpoint definitions to a file suitable for use
3017 in a later debugging session. To read the saved breakpoint
3018 definitions, use the `source' command.
3020 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3023 info static-tracepoint-markers
3024 Display information about static tracepoint markers in the target.
3026 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3027 Define a static tracepoint by probing a marker at the given
3028 function, line, address, or marker ID.
3032 Enable and disable observer mode.
3034 set may-write-registers on|off
3035 set may-write-memory on|off
3036 set may-insert-breakpoints on|off
3037 set may-insert-tracepoints on|off
3038 set may-insert-fast-tracepoints on|off
3039 set may-interrupt on|off
3040 Set individual permissions for GDB effects on the target. Note that
3041 some of these settings can have undesirable or surprising
3042 consequences, particularly when changed in the middle of a session.
3043 For instance, disabling the writing of memory can prevent
3044 breakpoints from being inserted, cause single-stepping to fail, or
3045 even crash your program, if you disable after breakpoints have been
3046 inserted. However, GDB should not crash.
3048 set record memory-query on|off
3049 show record memory-query
3050 Control whether to stop the inferior if memory changes caused
3051 by an instruction cannot be recorded.
3056 The disassemble command now supports "start,+length" form of two arguments.
3060 ** GDB now provides a new directory location, called the python directory,
3061 where Python scripts written for GDB can be installed. The location
3062 of that directory is <data-directory>/python, where <data-directory>
3063 is the GDB data directory. For more details, see section `Scripting
3064 GDB using Python' in the manual.
3066 ** The GDB Python API now has access to breakpoints, symbols, symbol
3067 tables, program spaces, inferiors, threads and frame's code blocks.
3068 Additionally, GDB Parameters can now be created from the API, and
3069 manipulated via set/show in the CLI.
3071 ** New functions gdb.target_charset, gdb.target_wide_charset,
3072 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3074 ** New exception gdb.GdbError.
3076 ** Pretty-printers are now also looked up in the current program space.
3078 ** Pretty-printers can now be individually enabled and disabled.
3080 ** GDB now looks for names of Python scripts to auto-load in a
3081 special section named `.debug_gdb_scripts', in addition to looking
3082 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3084 * Tracepoint actions were unified with breakpoint commands. In particular,
3085 there are no longer differences in "info break" output for breakpoints and
3086 tracepoints and the "commands" command can be used for both tracepoints and
3087 regular breakpoints.
3091 ARM Symbian arm*-*-symbianelf*
3093 * D language support.
3094 GDB now supports debugging programs written in the D programming
3097 * GDB now supports the extended ptrace interface for PowerPC which is
3098 available since Linux kernel version 2.6.34. This automatically enables
3099 any hardware breakpoints and additional hardware watchpoints available in
3100 the processor. The old ptrace interface exposes just one hardware
3101 watchpoint and no hardware breakpoints.
3103 * GDB is now able to use the Data Value Compare (DVC) register available on
3104 embedded PowerPC processors to implement in hardware simple watchpoint
3105 conditions of the form:
3107 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3109 This works in native GDB running on Linux kernels with the extended ptrace
3110 interface mentioned above.
3112 *** Changes in GDB 7.1
3116 ** Namespace Support
3118 GDB now supports importing of namespaces in C++. This enables the
3119 user to inspect variables from imported namespaces. Support for
3120 namepace aliasing has also been added. So, if a namespace is
3121 aliased in the current scope (e.g. namepace C=A; ) the user can
3122 print variables using the alias (e.g. (gdb) print C::x).
3126 All known bugs relating to the printing of virtual base class were
3127 fixed. It is now possible to call overloaded static methods using a
3132 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3133 and reinterpret_cast<> are now handled by the C++ expression parser.
3137 Xilinx MicroBlaze microblaze-*-*
3142 Xilinx MicroBlaze microblaze
3145 * Multi-program debugging.
3147 GDB now has support for multi-program (a.k.a. multi-executable or
3148 multi-exec) debugging. This allows for debugging multiple inferiors
3149 simultaneously each running a different program under the same GDB
3150 session. See "Debugging Multiple Inferiors and Programs" in the
3151 manual for more information. This implied some user visible changes
3152 in the multi-inferior support. For example, "info inferiors" now
3153 lists inferiors that are not running yet or that have exited
3154 already. See also "New commands" and "New options" below.
3156 * New tracing features
3158 GDB's tracepoint facility now includes several new features:
3160 ** Trace state variables
3162 GDB tracepoints now include support for trace state variables, which
3163 are variables managed by the target agent during a tracing
3164 experiment. They are useful for tracepoints that trigger each
3165 other, so for instance one tracepoint can count hits in a variable,
3166 and then a second tracepoint has a condition that is true when the
3167 count reaches a particular value. Trace state variables share the
3168 $-syntax of GDB convenience variables, and can appear in both
3169 tracepoint actions and condition expressions. Use the "tvariable"
3170 command to create, and "info tvariables" to view; see "Trace State
3171 Variables" in the manual for more detail.
3175 GDB now includes an option for defining fast tracepoints, which
3176 targets may implement more efficiently, such as by installing a jump
3177 into the target agent rather than a trap instruction. The resulting
3178 speedup can be by two orders of magnitude or more, although the
3179 tradeoff is that some program locations on some target architectures
3180 might not allow fast tracepoint installation, for instance if the
3181 instruction to be replaced is shorter than the jump. To request a
3182 fast tracepoint, use the "ftrace" command, with syntax identical to
3183 the regular trace command.
3185 ** Disconnected tracing
3187 It is now possible to detach GDB from the target while it is running
3188 a trace experiment, then reconnect later to see how the experiment
3189 is going. In addition, a new variable disconnected-tracing lets you
3190 tell the target agent whether to continue running a trace if the
3191 connection is lost unexpectedly.
3195 GDB now has the ability to save the trace buffer into a file, and
3196 then use that file as a target, similarly to you can do with
3197 corefiles. You can select trace frames, print data that was
3198 collected in them, and use tstatus to display the state of the
3199 tracing run at the moment that it was saved. To create a trace
3200 file, use "tsave <filename>", and to use it, do "target tfile
3203 ** Circular trace buffer
3205 You can ask the target agent to handle the trace buffer as a
3206 circular buffer, discarding the oldest trace frames to make room for
3207 newer ones, by setting circular-trace-buffer to on. This feature may
3208 not be available for all target agents.
3213 The disassemble command, when invoked with two arguments, now requires
3214 the arguments to be comma-separated.
3217 The info variables command now displays variable definitions. Files
3218 which only declare a variable are not shown.
3221 The source command is now capable of sourcing Python scripts.
3222 This feature is dependent on the debugger being build with Python
3225 Related to this enhancement is also the introduction of a new command
3226 "set script-extension" (see below).
3228 * New commands (for set/show, see "New options" below)
3230 record save [<FILENAME>]
3231 Save a file (in core file format) containing the process record
3232 execution log for replay debugging at a later time.
3234 record restore <FILENAME>
3235 Restore the process record execution log that was saved at an
3236 earlier time, for replay debugging.
3238 add-inferior [-copies <N>] [-exec <FILENAME>]
3241 clone-inferior [-copies <N>] [ID]
3242 Make a new inferior ready to execute the same program another
3243 inferior has loaded.
3248 maint info program-spaces
3249 List the program spaces loaded into GDB.
3251 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3252 show remote interrupt-sequence
3253 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3254 as the sequence to the remote target in order to interrupt the execution.
3255 Ctrl-C is a default. Some system prefers BREAK which is high level of
3256 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3257 Magic SysRq g. It is BREAK signal and character 'g'.
3259 set remote interrupt-on-connect [on | off]
3260 show remote interrupt-on-connect
3261 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3262 remote target when gdb connects to it. This is needed when you debug
3265 set remotebreak [on | off]
3267 Deprecated. Use "set/show remote interrupt-sequence" instead.
3269 tvariable $NAME [ = EXP ]
3270 Create or modify a trace state variable.
3273 List trace state variables and their values.
3275 delete tvariable $NAME ...
3276 Delete one or more trace state variables.
3279 Evaluate the given expressions without collecting anything into the
3280 trace buffer. (Valid in tracepoint actions only.)
3282 ftrace FN / FILE:LINE / *ADDR
3283 Define a fast tracepoint at the given function, line, or address.
3285 * New expression syntax
3287 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3288 GDB now parses 0b101010 identically with 42.
3292 set follow-exec-mode new|same
3293 show follow-exec-mode
3294 Control whether GDB reuses the same inferior across an exec call or
3295 creates a new one. This is useful to be able to restart the old
3296 executable after the inferior having done an exec call.
3298 set default-collect EXPR, ...
3299 show default-collect
3300 Define a list of expressions to be collected at each tracepoint.
3301 This is a useful way to ensure essential items are not overlooked,
3302 such as registers or a critical global variable.
3304 set disconnected-tracing
3305 show disconnected-tracing
3306 If set to 1, the target is instructed to continue tracing if it
3307 loses its connection to GDB. If 0, the target is to stop tracing
3310 set circular-trace-buffer
3311 show circular-trace-buffer
3312 If set to on, the target is instructed to use a circular trace buffer
3313 and discard the oldest trace frames instead of stopping the trace due
3314 to a full trace buffer. If set to off, the trace stops when the buffer
3315 fills up. Some targets may not support this.
3317 set script-extension off|soft|strict
3318 show script-extension
3319 If set to "off", the debugger does not perform any script language
3320 recognition, and all sourced files are assumed to be GDB scripts.
3321 If set to "soft" (the default), files are sourced according to
3322 filename extension, falling back to GDB scripts if the first
3324 If set to "strict", files are sourced according to filename extension.
3326 set ada trust-PAD-over-XVS on|off
3327 show ada trust-PAD-over-XVS
3328 If off, activate a workaround against a bug in the debugging information
3329 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3330 the GCC sources for more information about the GNAT encoding and
3331 PAD types in particular). It is always safe to set this option to
3332 off, but this introduces a slight performance penalty. The default
3335 * Python API Improvements
3337 ** GDB provides the new class gdb.LazyString. This is useful in
3338 some pretty-printing cases. The new method gdb.Value.lazy_string
3339 provides a simple way to create objects of this type.
3341 ** The fields returned by gdb.Type.fields now have an
3342 `is_base_class' attribute.
3344 ** The new method gdb.Type.range returns the range of an array type.
3346 ** The new method gdb.parse_and_eval can be used to parse and
3347 evaluate an expression.
3349 * New remote packets
3352 Define a trace state variable.
3355 Get the current value of a trace state variable.
3358 Set desired tracing behavior upon disconnection.
3361 Set the trace buffer to be linear or circular.
3364 Get data about the tracepoints currently in use.
3368 Process record now works correctly with hardware watchpoints.
3370 Multiple bug fixes have been made to the mips-irix port, making it
3371 much more reliable. In particular:
3372 - Debugging threaded applications is now possible again. Previously,
3373 GDB would hang while starting the program, or while waiting for
3374 the program to stop at a breakpoint.
3375 - Attaching to a running process no longer hangs.
3376 - An error occurring while loading a core file has been fixed.
3377 - Changing the value of the PC register now works again. This fixes
3378 problems observed when using the "jump" command, or when calling
3379 a function from GDB, or even when assigning a new value to $pc.
3380 - With the "finish" and "return" commands, the return value for functions
3381 returning a small array is now correctly printed.
3382 - It is now possible to break on shared library code which gets executed
3383 during a shared library init phase (code executed while executing
3384 their .init section). Previously, the breakpoint would have no effect.
3385 - GDB is now able to backtrace through the signal handler for
3386 non-threaded programs.
3388 PIE (Position Independent Executable) programs debugging is now supported.
3389 This includes debugging execution of PIC (Position Independent Code) shared
3390 libraries although for that, it should be possible to run such libraries as an
3393 *** Changes in GDB 7.0
3395 * GDB now has an interface for JIT compilation. Applications that
3396 dynamically generate code can create symbol files in memory and register
3397 them with GDB. For users, the feature should work transparently, and
3398 for JIT developers, the interface is documented in the GDB manual in the
3399 "JIT Compilation Interface" chapter.
3401 * Tracepoints may now be conditional. The syntax is as for
3402 breakpoints; either an "if" clause appended to the "trace" command,
3403 or the "condition" command is available. GDB sends the condition to
3404 the target for evaluation using the same bytecode format as is used
3405 for tracepoint actions.
3407 * The disassemble command now supports: an optional /r modifier, print the
3408 raw instructions in hex as well as in symbolic form, and an optional /m
3409 modifier to print mixed source+assembly.
3411 * Process record and replay
3413 In a architecture environment that supports ``process record and
3414 replay'', ``process record and replay'' target can record a log of
3415 the process execution, and replay it with both forward and reverse
3418 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3419 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3420 set execution-direction {forward|reverse}, for targets that support
3423 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3424 feature is available with a native GDB running on kernel version
3427 * GDB now has support for multi-byte and wide character sets on the
3428 target. Strings whose character type is wchar_t, char16_t, or
3429 char32_t are now correctly printed. GDB supports wide- and unicode-
3430 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3431 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3432 `printf'. This feature requires iconv to work properly; if your
3433 system does not have a working iconv, GDB can use GNU libiconv. See
3434 the installation instructions for more information.
3436 * GDB now supports automatic retrieval of shared library files from
3437 remote targets. To use this feature, specify a system root that begins
3438 with the `remote:' prefix, either via the `set sysroot' command or via
3439 the `--with-sysroot' configure-time option.
3441 * "info sharedlibrary" now takes an optional regex of libraries to show,
3442 and it now reports if a shared library has no debugging information.
3444 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3445 now complete on file names.
3447 * When completing in expressions, gdb will attempt to limit
3448 completions to allowable structure or union fields, where appropriate.
3449 For instance, consider:
3451 # struct example { int f1; double f2; };
3452 # struct example variable;
3455 If the user types TAB at the end of this command line, the available
3456 completions will be "f1" and "f2".
3458 * Inlined functions are now supported. They show up in backtraces, and
3459 the "step", "next", and "finish" commands handle them automatically.
3461 * GDB now supports the token-splicing (##) and stringification (#)
3462 operators when expanding macros. It also supports variable-arity
3465 * GDB now supports inspecting extra signal information, exported by
3466 the new $_siginfo convenience variable. The feature is currently
3467 implemented on linux ARM, i386 and amd64.
3469 * GDB can now display the VFP floating point registers and NEON vector
3470 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3471 can provide these registers (requires Linux 2.6.30 or later). Remote
3472 and simulator targets may also provide them.
3474 * New remote packets
3477 Search memory for a sequence of bytes.
3480 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3481 operation over reliable transport links. Use of this packet is
3482 controlled by the `set remote noack-packet' command.
3485 Kill the process with the specified process ID. Use this in preference
3486 to `k' when multiprocess protocol extensions are supported.
3489 Obtains additional operating system information
3493 Read or write additional signal information.
3495 * Removed remote protocol undocumented extension
3497 An undocumented extension to the remote protocol's `S' stop reply
3498 packet that permited the stub to pass a process id was removed.
3499 Remote servers should use the `T' stop reply packet instead.
3501 * GDB now supports multiple function calling conventions according to the
3502 DWARF-2 DW_AT_calling_convention function attribute.
3504 * The SH target utilizes the aforementioned change to distinguish between gcc
3505 and Renesas calling convention. It also adds the new CLI commands
3506 `set/show sh calling-convention'.
3508 * GDB can now read compressed debug sections, as produced by GNU gold
3509 with the --compress-debug-sections=zlib flag.
3511 * 64-bit core files are now supported on AIX.
3513 * Thread switching is now supported on Tru64.
3515 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3516 which will be allocated using malloc later in program execution.
3518 * The qXfer:libraries:read remote procotol packet now allows passing a
3519 list of section offsets.
3521 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3522 conditions handling signals delivered during attach or thread creation
3523 have also been fixed.
3525 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3526 From the user's standpoint, all unqualified instances of True and False
3527 are treated as the standard definitions, regardless of context.
3529 * GDB now parses C++ symbol and type names more flexibly. For
3532 template<typename T> class C { };
3535 GDB will now correctly handle all of:
3537 ptype C<char const *>
3538 ptype C<char const*>
3539 ptype C<const char *>
3540 ptype C<const char*>
3542 * New features in the GDB remote stub, gdbserver
3544 - The "--wrapper" command-line argument tells gdbserver to use a
3545 wrapper program to launch programs for debugging.
3547 - On PowerPC and S/390 targets, it is now possible to use a single
3548 gdbserver executable to debug both 32-bit and 64-bit programs.
3549 (This requires gdbserver itself to be built as a 64-bit executable.)
3551 - gdbserver uses the new noack protocol mode for TCP connections to
3552 reduce communications latency, if also supported and enabled in GDB.
3554 - Support for the sparc64-linux-gnu target is now included in
3557 - The amd64-linux build of gdbserver now supports debugging both
3558 32-bit and 64-bit programs.
3560 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3561 now support hardware watchpoints, and will use them automatically
3566 GDB now has support for scripting using Python. Whether this is
3567 available is determined at configure time.
3569 New GDB commands can now be written in Python.
3571 * Ada tasking support
3573 Ada tasks can now be inspected in GDB. The following commands have
3577 Print the list of Ada tasks.
3579 Print detailed information about task number N.
3581 Print the task number of the current task.
3583 Switch the context of debugging to task number N.
3585 * Support for user-defined prefixed commands. The "define" command can
3586 add new commands to existing prefixes, e.g. "target".
3588 * Multi-inferior, multi-process debugging.
3590 GDB now has generalized support for multi-inferior debugging. See
3591 "Debugging Multiple Inferiors" in the manual for more information.
3592 Although availability still depends on target support, the command
3593 set is more uniform now. The GNU/Linux specific multi-forks support
3594 has been migrated to this new framework. This implied some user
3595 visible changes; see "New commands" and also "Removed commands"
3598 * Target descriptions can now describe the target OS ABI. See the
3599 "Target Description Format" section in the user manual for more
3602 * Target descriptions can now describe "compatible" architectures
3603 to indicate that the target can execute applications for a different
3604 architecture in addition to those for the main target architecture.
3605 See the "Target Description Format" section in the user manual for
3608 * Multi-architecture debugging.
3610 GDB now includes general supports for debugging applications on
3611 hybrid systems that use more than one single processor architecture
3612 at the same time. Each such hybrid architecture still requires
3613 specific support to be added. The only hybrid architecture supported
3614 in this version of GDB is the Cell Broadband Engine.
3616 * GDB now supports integrated debugging of Cell/B.E. applications that
3617 use both the PPU and SPU architectures. To enable support for hybrid
3618 Cell/B.E. debugging, you need to configure GDB to support both the
3619 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3620 --enable-targets configure option.
3622 * Non-stop mode debugging.
3624 For some targets, GDB now supports an optional mode of operation in
3625 which you can examine stopped threads while other threads continue
3626 to execute freely. This is referred to as non-stop mode, with the
3627 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3628 section in the user manual for more information.
3630 To be able to support remote non-stop debugging, a remote stub needs
3631 to implement the non-stop mode remote protocol extensions, as
3632 described in the "Remote Non-Stop" section of the user manual. The
3633 GDB remote stub, gdbserver, has been adjusted to support these
3634 extensions on linux targets.
3636 * New commands (for set/show, see "New options" below)
3638 catch syscall [NAME(S) | NUMBER(S)]
3639 Catch system calls. Arguments, which should be names of system
3640 calls or their numbers, mean catch only those syscalls. Without
3641 arguments, every syscall will be caught. When the inferior issues
3642 any of the specified syscalls, GDB will stop and announce the system
3643 call, both when it is called and when its call returns. This
3644 feature is currently available with a native GDB running on the
3645 Linux Kernel, under the following architectures: x86, x86_64,
3646 PowerPC and PowerPC64.
3648 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3650 Search memory for a sequence of bytes.
3652 maint set python print-stack
3653 maint show python print-stack
3654 Show a stack trace when an error is encountered in a Python script.
3657 Invoke CODE by passing it to the Python interpreter.
3662 These allow macros to be defined, undefined, and listed
3666 Show operating system information about processes.
3669 List the inferiors currently under GDB's control.
3672 Switch focus to inferior number NUM.
3675 Detach from inferior number NUM.
3678 Kill inferior number NUM.
3682 set spu stop-on-load
3683 show spu stop-on-load
3684 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3686 set spu auto-flush-cache
3687 show spu auto-flush-cache
3688 Control whether to automatically flush the software-managed cache
3689 during Cell/B.E. debugging.
3691 set sh calling-convention
3692 show sh calling-convention
3693 Control the calling convention used when calling SH target functions.
3696 show debug timestamp
3697 Control display of timestamps with GDB debugging output.
3699 set disassemble-next-line
3700 show disassemble-next-line
3701 Control display of disassembled source lines or instructions when
3704 set remote noack-packet
3705 show remote noack-packet
3706 Set/show the use of remote protocol QStartNoAckMode packet. See above
3707 under "New remote packets."
3709 set remote query-attached-packet
3710 show remote query-attached-packet
3711 Control use of remote protocol `qAttached' (query-attached) packet.
3713 set remote read-siginfo-object
3714 show remote read-siginfo-object
3715 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3718 set remote write-siginfo-object
3719 show remote write-siginfo-object
3720 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3723 set remote reverse-continue
3724 show remote reverse-continue
3725 Control use of remote protocol 'bc' (reverse-continue) packet.
3727 set remote reverse-step
3728 show remote reverse-step
3729 Control use of remote protocol 'bs' (reverse-step) packet.
3731 set displaced-stepping
3732 show displaced-stepping
3733 Control displaced stepping mode. Displaced stepping is a way to
3734 single-step over breakpoints without removing them from the debuggee.
3735 Also known as "out-of-line single-stepping".
3738 show debug displaced
3739 Control display of debugging info for displaced stepping.
3741 maint set internal-error
3742 maint show internal-error
3743 Control what GDB does when an internal error is detected.
3745 maint set internal-warning
3746 maint show internal-warning
3747 Control what GDB does when an internal warning is detected.
3752 Use a wrapper program to launch programs for debugging.
3754 set multiple-symbols (all|ask|cancel)
3755 show multiple-symbols
3756 The value of this variable can be changed to adjust the debugger behavior
3757 when an expression or a breakpoint location contains an ambiguous symbol
3758 name (an overloaded function name, for instance).
3760 set breakpoint always-inserted
3761 show breakpoint always-inserted
3762 Keep breakpoints always inserted in the target, as opposed to inserting
3763 them when resuming the target, and removing them when the target stops.
3764 This option can improve debugger performance on slow remote targets.
3766 set arm fallback-mode (arm|thumb|auto)
3767 show arm fallback-mode
3768 set arm force-mode (arm|thumb|auto)
3770 These commands control how ARM GDB determines whether instructions
3771 are ARM or Thumb. The default for both settings is auto, which uses
3772 the current CPSR value for instructions without symbols; previous
3773 versions of GDB behaved as if "set arm fallback-mode arm".
3775 set disable-randomization
3776 show disable-randomization
3777 Standalone programs run with the virtual address space randomization enabled
3778 by default on some platforms. This option keeps the addresses stable across
3779 multiple debugging sessions.
3783 Control whether other threads are stopped or not when some thread hits
3788 Requests that asynchronous execution is enabled in the target, if available.
3789 In this case, it's possible to resume target in the background, and interact
3790 with GDB while the target is running. "show target-async" displays the
3791 current state of asynchronous execution of the target.
3793 set target-wide-charset
3794 show target-wide-charset
3795 The target-wide-charset is the name of the character set that GDB
3796 uses when printing characters whose type is wchar_t.
3798 set tcp auto-retry (on|off)
3800 set tcp connect-timeout
3801 show tcp connect-timeout
3802 These commands allow GDB to retry failed TCP connections to a remote stub
3803 with a specified timeout period; this is useful if the stub is launched
3804 in parallel with GDB but may not be ready to accept connections immediately.
3806 set libthread-db-search-path
3807 show libthread-db-search-path
3808 Control list of directories which GDB will search for appropriate
3811 set schedule-multiple (on|off)
3812 show schedule-multiple
3813 Allow GDB to resume all threads of all processes or only threads of
3814 the current process.
3818 Use more aggressive caching for accesses to the stack. This improves
3819 performance of remote debugging (particularly backtraces) without
3820 affecting correctness.
3822 set interactive-mode (on|off|auto)
3823 show interactive-mode
3824 Control whether GDB runs in interactive mode (on) or not (off).
3825 When in interactive mode, GDB waits for the user to answer all
3826 queries. Otherwise, GDB does not wait and assumes the default
3827 answer. When set to auto (the default), GDB determines which
3828 mode to use based on the stdin settings.
3833 For program forks, this is replaced by the new more generic `info
3834 inferiors' command. To list checkpoints, you can still use the
3835 `info checkpoints' command, which was an alias for the `info forks'
3839 Replaced by the new `inferior' command. To switch between
3840 checkpoints, you can still use the `restart' command, which was an
3841 alias for the `fork' command.
3844 This is removed, since some targets don't have a notion of
3845 processes. To switch between processes, you can still use the
3846 `inferior' command using GDB's own inferior number.
3849 For program forks, this is replaced by the new more generic `kill
3850 inferior' command. To delete a checkpoint, you can still use the
3851 `delete checkpoint' command, which was an alias for the `delete
3855 For program forks, this is replaced by the new more generic `detach
3856 inferior' command. To detach a checkpoint, you can still use the
3857 `detach checkpoint' command, which was an alias for the `detach
3860 * New native configurations
3862 x86/x86_64 Darwin i[34567]86-*-darwin*
3864 x86_64 MinGW x86_64-*-mingw*
3868 Lattice Mico32 lm32-*
3869 x86 DICOS i[34567]86-*-dicos*
3870 x86_64 DICOS x86_64-*-dicos*
3873 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3874 (mingw32ce) debugging.
3880 These commands were actually not implemented on any target.
3882 *** Changes in GDB 6.8
3884 * New native configurations
3886 NetBSD/hppa hppa*-*netbsd*
3887 Xtensa GNU/Linux xtensa*-*-linux*
3891 NetBSD/hppa hppa*-*-netbsd*
3892 Xtensa GNU/Lunux xtensa*-*-linux*
3894 * Change in command line behavior -- corefiles vs. process ids.
3896 When the '-p NUMBER' or '--pid NUMBER' options are used, and
3897 attaching to process NUMBER fails, GDB no longer attempts to open a
3898 core file named NUMBER. Attaching to a program using the -c option
3899 is no longer supported. Instead, use the '-p' or '--pid' options.
3901 * GDB can now be built as a native debugger for debugging Windows x86
3902 (mingw32) Portable Executable (PE) programs.
3904 * Pending breakpoints no longer change their number when their address
3907 * GDB now supports breakpoints with multiple locations,
3908 including breakpoints on C++ constructors, inside C++ templates,
3909 and in inlined functions.
3911 * GDB's ability to debug optimized code has been improved. GDB more
3912 accurately identifies function bodies and lexical blocks that occupy
3913 more than one contiguous range of addresses.
3915 * Target descriptions can now describe registers for PowerPC.
3917 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
3918 registers on PowerPC targets.
3920 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
3921 targets even when the libthread_db library is not available.
3923 * The GDB remote stub, gdbserver, now supports the new file transfer
3924 commands (remote put, remote get, and remote delete).
3926 * The GDB remote stub, gdbserver, now supports run and attach in
3927 extended-remote mode.
3929 * hppa*64*-*-hpux11* target broken
3930 The debugger is unable to start a program and fails with the following
3931 error: "Error trying to get information about dynamic linker".
3932 The gdb-6.7 release is also affected.
3934 * GDB now supports the --enable-targets= configure option to allow
3935 building a single GDB executable that supports multiple remote
3936 target architectures.
3938 * GDB now supports debugging C and C++ programs which use the
3939 Decimal Floating Point extension. In addition, the PowerPC target
3940 now has a set of pseudo-registers to inspect decimal float values
3941 stored in two consecutive float registers.
3943 * The -break-insert MI command can optionally create pending
3946 * Improved support for debugging Ada
3947 Many improvements to the Ada language support have been made. These
3949 - Better support for Ada2005 interface types
3950 - Improved handling of arrays and slices in general
3951 - Better support for Taft-amendment types
3952 - The '{type} ADDRESS' expression is now allowed on the left hand-side
3954 - Improved command completion in Ada
3957 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
3962 set print frame-arguments (all|scalars|none)
3963 show print frame-arguments
3964 The value of this variable can be changed to control which argument
3965 values should be printed by the debugger when displaying a frame.
3970 Transfer files to and from a remote target, and delete remote files.
3977 Transfer files to and from a remote target, and delete remote files.
3979 * New remote packets
3986 Open, close, read, write, and delete files on the remote system.
3989 Attach to an existing process on the remote system, in extended-remote
3993 Run a new process on the remote system, in extended-remote mode.
3995 *** Changes in GDB 6.7
3997 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
3998 bfd, libiberty and opcodes, as revealed by static analysis donated by
3999 Coverity, Inc. (http://scan.coverity.com).
4001 * When looking up multiply-defined global symbols, GDB will now prefer the
4002 symbol definition in the current shared library if it was built using the
4003 -Bsymbolic linker option.
4005 * When the Text User Interface (TUI) is not configured, GDB will now
4006 recognize the -tui command-line option and print a message that the TUI
4009 * The GDB remote stub, gdbserver, now has lower overhead for high
4010 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4012 * GDB for MIPS targets now autodetects whether a remote target provides
4013 32-bit or 64-bit register values.
4015 * Support for C++ member pointers has been improved.
4017 * GDB now understands XML target descriptions, which specify the
4018 target's overall architecture. GDB can read a description from
4019 a local file or over the remote serial protocol.
4021 * Vectors of single-byte data use a new integer type which is not
4022 automatically displayed as character or string data.
4024 * The /s format now works with the print command. It displays
4025 arrays of single-byte integers and pointers to single-byte integers
4028 * Target descriptions can now describe target-specific registers,
4029 for architectures which have implemented the support (currently
4030 only ARM, M68K, and MIPS).
4032 * GDB and the GDB remote stub, gdbserver, now support the XScale
4035 * The GDB remote stub, gdbserver, has been updated to support
4036 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4037 has been rewritten to use the standard GDB remote protocol.
4039 * GDB can now step into C++ functions which are called through thunks.
4041 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4043 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4044 layout. It also supports a TextSeg= and DataSeg= response when only
4045 segment base addresses (rather than offsets) are available.
4047 * The /i format now outputs any trailing branch delay slot instructions
4048 immediately following the last instruction within the count specified.
4050 * The GDB remote protocol "T" stop reply packet now supports a
4051 "library" response. Combined with the new "qXfer:libraries:read"
4052 packet, this response allows GDB to debug shared libraries on targets
4053 where the operating system manages the list of loaded libraries (e.g.
4054 Windows and SymbianOS).
4056 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4057 (DLLs) on Windows and Windows CE targets.
4059 * GDB now supports a faster verification that a .debug file matches its binary
4060 according to its build-id signature, if the signature is present.
4066 Enable or disable hardware flow control (RTS/CTS) on the serial port
4067 when debugging using remote targets.
4069 set mem inaccessible-by-default
4070 show mem inaccessible-by-default
4071 If the target supplies a memory map, for instance via the remote
4072 protocol's "qXfer:memory-map:read" packet, setting this variable
4073 prevents GDB from accessing memory outside the memory map. This
4074 is useful for targets with memory mapped registers or which react
4075 badly to accesses of unmapped address space.
4077 set breakpoint auto-hw
4078 show breakpoint auto-hw
4079 If the target supplies a memory map, for instance via the remote
4080 protocol's "qXfer:memory-map:read" packet, setting this variable
4081 lets GDB use hardware breakpoints automatically for memory regions
4082 where it can not use software breakpoints. This covers both the
4083 "break" command and internal breakpoints used for other commands
4084 including "next" and "finish".
4087 catch exception unhandled
4088 Stop the program execution when Ada exceptions are raised.
4091 Stop the program execution when an Ada assertion failed.
4095 Set an alternate system root for target files. This is a more
4096 general version of "set solib-absolute-prefix", which is now
4097 an alias to "set sysroot".
4100 Provide extended SPU facility status information. This set of
4101 commands is available only when debugging the Cell/B.E. SPU
4104 * New native configurations
4106 OpenBSD/sh sh*-*openbsd*
4109 unset tdesc filename
4111 Use the specified local file as an XML target description, and do
4112 not query the target for its built-in description.
4116 OpenBSD/sh sh*-*-openbsd*
4117 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4118 Toshiba Media Processor mep-elf
4120 * New remote packets
4123 Ignore the specified signals; pass them directly to the debugged program
4124 without stopping other threads or reporting them to GDB.
4126 qXfer:features:read:
4127 Read an XML target description from the target, which describes its
4132 Read or write contents of an spufs file on the target system. These
4133 packets are available only on the Cell/B.E. SPU architecture.
4135 qXfer:libraries:read:
4136 Report the loaded shared libraries. Combined with new "T" packet
4137 response, this packet allows GDB to debug shared libraries on
4138 targets where the operating system manages the list of loaded
4139 libraries (e.g. Windows and SymbianOS).
4143 Support for these obsolete configurations has been removed.
4151 i[34567]86-*-lynxos*
4152 i[34567]86-*-netware*
4153 i[34567]86-*-sco3.2v5*
4154 i[34567]86-*-sco3.2v4*
4156 i[34567]86-*-sysv4.2*
4159 i[34567]86-*-unixware2*
4160 i[34567]86-*-unixware*
4169 * Other removed features
4176 Various m68k-only ROM monitors.
4183 Various Renesas ROM monitors and debugging interfaces for SH and
4188 Support for a Macraigor serial interface to on-chip debugging.
4189 GDB does not directly support the newer parallel or USB
4194 A debug information format. The predecessor to DWARF 2 and
4195 DWARF 3, which are still supported.
4197 Support for the HP aCC compiler on HP-UX/PA-RISC
4199 SOM-encapsulated symbolic debugging information, automatic
4200 invocation of pxdb, and the aCC custom C++ ABI. This does not
4201 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4202 with aCC can still be debugged on an assembly level.
4204 MIPS ".pdr" sections
4206 A MIPS-specific format used to describe stack frame layout
4207 in debugging information.
4211 GDB could work with an older version of Guile to debug
4212 the interpreter and Scheme programs running in it.
4214 set mips stack-arg-size
4215 set mips saved-gpreg-size
4217 Use "set mips abi" to control parameter passing for MIPS.
4219 *** Changes in GDB 6.6
4224 Cell Broadband Engine SPU spu-elf
4226 * GDB can now be configured as a cross-debugger targeting native Windows
4227 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4228 running on a Windows system over TCP/IP to debug Windows programs.
4230 * The GDB remote stub, gdbserver, has been updated to support Windows and
4231 Cygwin debugging. Both single-threaded and multi-threaded programs are
4234 * The "set trust-readonly-sections" command works again. This command was
4235 broken in GDB 6.3, 6.4, and 6.5.
4237 * The "load" command now supports writing to flash memory, if the remote
4238 stub provides the required support.
4240 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4241 longer requires symbolic debug information (e.g. DWARF-2).
4246 unset substitute-path
4247 show substitute-path
4248 Manage a list of substitution rules that GDB uses to rewrite the name
4249 of the directories where the sources are located. This can be useful
4250 for instance when the sources were moved to a different location
4251 between compilation and debugging.
4255 Print each CLI command as it is executed. Each command is prefixed with
4256 a number of `+' symbols representing the nesting depth.
4257 The source command now has a `-v' option to enable the same feature.
4261 The ARM Demon monitor support (RDP protocol, "target rdp").
4263 Kernel Object Display, an embedded debugging feature which only worked with
4264 an obsolete version of Cisco IOS.
4266 The 'set download-write-size' and 'show download-write-size' commands.
4268 * New remote packets
4271 Tell a stub about GDB client features, and request remote target features.
4272 The first feature implemented is PacketSize, which allows the target to
4273 specify the size of packets it can handle - to minimize the number of
4274 packets required and improve performance when connected to a remote
4278 Fetch an OS auxilliary vector from the remote stub. This packet is a
4279 more efficient replacement for qPart:auxv:read.
4281 qXfer:memory-map:read:
4282 Fetch a memory map from the remote stub, including information about
4283 RAM, ROM, and flash memory devices.
4288 Erase and program a flash memory device.
4290 * Removed remote packets
4293 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4294 used it, and only gdbserver implemented it.
4296 *** Changes in GDB 6.5
4300 Renesas M32C/M16C m32c-elf
4302 Morpho Technologies ms1 ms1-elf
4306 init-if-undefined Initialize a convenience variable, but
4307 only if it doesn't already have a value.
4309 The following commands are presently only implemented for native GNU/Linux:
4311 checkpoint Save a snapshot of the program state.
4313 restart <n> Return the program state to a
4314 previously saved state.
4316 info checkpoints List currently saved checkpoints.
4318 delete-checkpoint <n> Delete a previously saved checkpoint.
4320 set|show detach-on-fork Tell gdb whether to detach from a newly
4321 forked process, or to keep debugging it.
4323 info forks List forks of the user program that
4324 are available to be debugged.
4326 fork <n> Switch to debugging one of several
4327 forks of the user program that are
4328 available to be debugged.
4330 delete-fork <n> Delete a fork from the list of forks
4331 that are available to be debugged (and
4332 kill the forked process).
4334 detach-fork <n> Delete a fork from the list of forks
4335 that are available to be debugged (and
4336 allow the process to continue).
4340 Morpho Technologies ms2 ms1-elf
4342 * Improved Windows host support
4344 GDB now builds as a cross debugger hosted on i686-mingw32, including
4345 native console support, and remote communications using either
4346 network sockets or serial ports.
4348 * Improved Modula-2 language support
4350 GDB can now print most types in the Modula-2 syntax. This includes:
4351 basic types, set types, record types, enumerated types, range types,
4352 pointer types and ARRAY types. Procedure var parameters are correctly
4353 printed and hexadecimal addresses and character constants are also
4354 written in the Modula-2 syntax. Best results can be obtained by using
4355 GNU Modula-2 together with the -gdwarf-2 command line option.
4359 The ARM rdi-share module.
4361 The Netware NLM debug server.
4363 *** Changes in GDB 6.4
4365 * New native configurations
4367 OpenBSD/arm arm*-*-openbsd*
4368 OpenBSD/mips64 mips64-*-openbsd*
4372 Morpho Technologies ms1 ms1-elf
4374 * New command line options
4376 --batch-silent As for --batch, but totally silent.
4377 --return-child-result The debugger will exist with the same value
4378 the child (debugged) program exited with.
4379 --eval-command COMMAND, -ex COMMAND
4380 Execute a single GDB CLI command. This may be
4381 specified multiple times and in conjunction
4382 with the --command (-x) option.
4384 * Deprecated commands removed
4386 The following commands, that were deprecated in 2000, have been
4390 set|show arm disassembly-flavor set|show arm disassembler
4391 othernames set arm disassembler
4392 set|show remotedebug set|show debug remote
4393 set|show archdebug set|show debug arch
4394 set|show eventdebug set|show debug event
4397 * New BSD user-level threads support
4399 It is now possible to debug programs using the user-level threads
4400 library on OpenBSD and FreeBSD. Currently supported (target)
4403 FreeBSD/amd64 x86_64-*-freebsd*
4404 FreeBSD/i386 i386-*-freebsd*
4405 OpenBSD/i386 i386-*-openbsd*
4407 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4408 are not yet supported.
4410 * New support for Matsushita MN10300 w/sim added
4411 (Work in progress). mn10300-elf.
4413 * REMOVED configurations and files
4415 VxWorks and the XDR protocol *-*-vxworks
4416 Motorola MCORE mcore-*-*
4417 National Semiconductor NS32000 ns32k-*-*
4419 * New "set print array-indexes" command
4421 After turning this setting "on", GDB prints the index of each element
4422 when displaying arrays. The default is "off" to preserve the previous
4425 * VAX floating point support
4427 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4429 * User-defined command support
4431 In addition to using $arg0..$arg9 for argument passing, it is now possible
4432 to use $argc to determine now many arguments have been passed. See the
4433 section on user-defined commands in the user manual for more information.
4435 *** Changes in GDB 6.3:
4437 * New command line option
4439 GDB now accepts -l followed by a number to set the timeout for remote
4442 * GDB works with GCC -feliminate-dwarf2-dups
4444 GDB now supports a more compact representation of DWARF-2 debug
4445 information using DW_FORM_ref_addr references. These are produced
4446 by GCC with the option -feliminate-dwarf2-dups and also by some
4447 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4448 to use -feliminate-dwarf2-dups.
4450 * Internationalization
4452 When supported by the host system, GDB will be built with
4453 internationalization (libintl). The task of marking up the sources is
4454 continued, we're looking forward to our first translation.
4458 Initial support for debugging programs compiled with the GNAT
4459 implementation of the Ada programming language has been integrated
4460 into GDB. In this release, support is limited to expression evaluation.
4462 * New native configurations
4464 GNU/Linux/m32r m32r-*-linux-gnu
4468 GDB's remote protocol now includes support for the 'p' packet. This
4469 packet is used to fetch individual registers from a remote inferior.
4471 * END-OF-LIFE registers[] compatibility module
4473 GDB's internal register infrastructure has been completely rewritten.
4474 The new infrastructure making possible the implementation of key new
4475 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4478 GDB 6.3 will be the last release to include the the registers[]
4479 compatibility module that allowed out-of-date configurations to
4480 continue to work. This change directly impacts the following
4490 powerpc bdm protocol
4492 Unless there is activity to revive these configurations, they will be
4493 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4495 * OBSOLETE configurations and files
4497 Configurations that have been declared obsolete in this release have
4498 been commented out. Unless there is activity to revive these
4499 configurations, the next release of GDB will have their sources
4500 permanently REMOVED.
4509 *** Changes in GDB 6.2.1:
4511 * MIPS `break main; run' gave an heuristic-fence-post warning
4513 When attempting to run even a simple program, a warning about
4514 heuristic-fence-post being hit would be reported. This problem has
4517 * MIPS IRIX 'long double' crashed GDB
4519 When examining a long double variable, GDB would get a segmentation
4520 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4521 IRIX long double values).
4525 A bug in the VAX stack code was causing problems with the "next"
4526 command. This problem has been fixed.
4528 *** Changes in GDB 6.2:
4530 * Fix for ``many threads''
4532 On GNU/Linux systems that use the NPTL threads library, a program
4533 rapidly creating and deleting threads would confuse GDB leading to the
4536 ptrace: No such process.
4537 thread_db_get_info: cannot get thread info: generic error
4539 This problem has been fixed.
4541 * "-async" and "-noasync" options removed.
4543 Support for the broken "-noasync" option has been removed (it caused
4546 * New ``start'' command.
4548 This command runs the program until the begining of the main procedure.
4550 * New BSD Kernel Data Access Library (libkvm) interface
4552 Using ``target kvm'' it is now possible to debug kernel core dumps and
4553 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4554 platforms. Currently supported (native-only) configurations are:
4556 FreeBSD/amd64 x86_64-*-freebsd*
4557 FreeBSD/i386 i?86-*-freebsd*
4558 NetBSD/i386 i?86-*-netbsd*
4559 NetBSD/m68k m68*-*-netbsd*
4560 NetBSD/sparc sparc-*-netbsd*
4561 OpenBSD/amd64 x86_64-*-openbsd*
4562 OpenBSD/i386 i?86-*-openbsd*
4563 OpenBSD/m68k m68*-openbsd*
4564 OpenBSD/sparc sparc-*-openbsd*
4566 * Signal trampoline code overhauled
4568 Many generic problems with GDB's signal handling code have been fixed.
4569 These include: backtraces through non-contiguous stacks; recognition
4570 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4571 call; backtrace through a signal trampoline; step into and out of
4572 signal handlers; and single-stepping in the signal trampoline.
4574 Please note that kernel bugs are a limiting factor here. These
4575 features have been shown to work on an s390 GNU/Linux system that
4576 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4578 * Cygwin support for DWARF 2 added.
4580 * New native configurations
4582 GNU/Linux/hppa hppa*-*-linux*
4583 OpenBSD/hppa hppa*-*-openbsd*
4584 OpenBSD/m68k m68*-*-openbsd*
4585 OpenBSD/m88k m88*-*-openbsd*
4586 OpenBSD/powerpc powerpc-*-openbsd*
4587 NetBSD/vax vax-*-netbsd*
4588 OpenBSD/vax vax-*-openbsd*
4590 * END-OF-LIFE frame compatibility module
4592 GDB's internal frame infrastructure has been completely rewritten.
4593 The new infrastructure making it possible to support key new features
4594 including DWARF 2 Call Frame Information. To aid in the task of
4595 migrating old configurations to this new infrastructure, a
4596 compatibility module, that allowed old configurations to continue to
4597 work, was also included.
4599 GDB 6.2 will be the last release to include this frame compatibility
4600 module. This change directly impacts the following configurations:
4610 Unless there is activity to revive these configurations, they will be
4611 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4613 * REMOVED configurations and files
4615 Sun 3, running SunOS 3 m68*-*-sunos3*
4616 Sun 3, running SunOS 4 m68*-*-sunos4*
4617 Sun 2, running SunOS 3 m68000-*-sunos3*
4618 Sun 2, running SunOS 4 m68000-*-sunos4*
4619 Motorola 680x0 running LynxOS m68*-*-lynxos*
4620 AT&T 3b1/Unix pc m68*-att-*
4621 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4622 decstation mips-dec-* mips-little-*
4623 riscos mips-*-riscos* mips-*-sysv*
4624 sonymips mips-sony-*
4625 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4627 *** Changes in GDB 6.1.1:
4629 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4631 The TUI (Text-mode User Interface) is now built as part of a default
4632 GDB configuration. It is enabled by either selecting the TUI with the
4633 command line option "-i=tui" or by running the separate "gdbtui"
4634 program. For more information on the TUI, see the manual "Debugging
4637 * Pending breakpoint support (also included in GDB 6.1)
4639 Support has been added to allow you to specify breakpoints in shared
4640 libraries that have not yet been loaded. If a breakpoint location
4641 cannot be found, and the "breakpoint pending" option is set to auto,
4642 GDB queries you if you wish to make the breakpoint pending on a future
4643 shared-library load. If and when GDB resolves the breakpoint symbol,
4644 the pending breakpoint is removed as one or more regular breakpoints
4647 Pending breakpoints are very useful for GCJ Java debugging.
4649 * Fixed ISO-C build problems
4651 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4652 non ISO-C code that stopped them being built using a more strict ISO-C
4653 compiler (e.g., IBM's C compiler).
4655 * Fixed build problem on IRIX 5
4657 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4658 wasn't able to compile compile on an IRIX 5 system.
4660 * Added execute permission to gdb/gdbserver/configure
4662 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4663 permission. This bug would cause configure to fail on a number of
4664 systems (Solaris, IRIX). Ref: server/519.
4666 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4668 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4669 has been updated to use constant array sizes.
4671 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4673 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4674 its generated DWARF Call Frame Info. This encoding was causing GDB to
4675 panic, that panic has been fixed. Ref: gdb/1628.
4677 * Fixed a problem when examining parameters in shared library code.
4679 When examining parameters in optimized shared library code generated
4680 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4681 not available''. GDB now correctly displays the variable's value.
4683 *** Changes in GDB 6.1:
4685 * Removed --with-mmalloc
4687 Support for the mmalloc memory manager has been removed, as it
4688 conflicted with the internal gdb byte cache.
4690 * Changes in AMD64 configurations
4692 The AMD64 target now includes the %cs and %ss registers. As a result
4693 the AMD64 remote protocol has changed; this affects the floating-point
4694 and SSE registers. If you rely on those registers for your debugging,
4695 you should upgrade gdbserver on the remote side.
4697 * Revised SPARC target
4699 The SPARC target has been completely revised, incorporating the
4700 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4701 support for LynxOS and SunOS 4 has been dropped. Calling functions
4702 from within GDB on operating systems with a non-executable stack
4703 (Solaris, OpenBSD) now works.
4707 GDB has a new C++ demangler which does a better job on the mangled
4708 names generated by current versions of g++. It also runs faster, so
4709 with this and other changes gdb should now start faster on large C++
4712 * DWARF 2 Location Expressions
4714 GDB support for location expressions has been extended to support function
4715 arguments and frame bases. Older versions of GDB could crash when they
4718 * C++ nested types and namespaces
4720 GDB's support for nested types and namespaces in C++ has been
4721 improved, especially if you use the DWARF 2 debugging format. (This
4722 is the default for recent versions of GCC on most platforms.)
4723 Specifically, if you have a class "Inner" defined within a class or
4724 namespace "Outer", then GDB realizes that the class's name is
4725 "Outer::Inner", not simply "Inner". This should greatly reduce the
4726 frequency of complaints about not finding RTTI symbols. In addition,
4727 if you are stopped at inside of a function defined within a namespace,
4728 GDB modifies its name lookup accordingly.
4730 * New native configurations
4732 NetBSD/amd64 x86_64-*-netbsd*
4733 OpenBSD/amd64 x86_64-*-openbsd*
4734 OpenBSD/alpha alpha*-*-openbsd*
4735 OpenBSD/sparc sparc-*-openbsd*
4736 OpenBSD/sparc64 sparc64-*-openbsd*
4738 * New debugging protocols
4740 M32R with SDI protocol m32r-*-elf*
4742 * "set prompt-escape-char" command deleted.
4744 The command "set prompt-escape-char" has been deleted. This command,
4745 and its very obscure effet on GDB's prompt, was never documented,
4746 tested, nor mentioned in the NEWS file.
4748 * OBSOLETE configurations and files
4750 Configurations that have been declared obsolete in this release have
4751 been commented out. Unless there is activity to revive these
4752 configurations, the next release of GDB will have their sources
4753 permanently REMOVED.
4755 Sun 3, running SunOS 3 m68*-*-sunos3*
4756 Sun 3, running SunOS 4 m68*-*-sunos4*
4757 Sun 2, running SunOS 3 m68000-*-sunos3*
4758 Sun 2, running SunOS 4 m68000-*-sunos4*
4759 Motorola 680x0 running LynxOS m68*-*-lynxos*
4760 AT&T 3b1/Unix pc m68*-att-*
4761 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4762 decstation mips-dec-* mips-little-*
4763 riscos mips-*-riscos* mips-*-sysv*
4764 sonymips mips-sony-*
4765 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4767 * REMOVED configurations and files
4769 SGI Irix-4.x mips-sgi-irix4 or iris4
4770 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4771 Z8000 simulator z8k-zilog-none or z8ksim
4772 Matsushita MN10200 w/simulator mn10200-*-*
4773 H8/500 simulator h8500-hitachi-hms or h8500hms
4774 HP/PA running BSD hppa*-*-bsd*
4775 HP/PA running OSF/1 hppa*-*-osf*
4776 HP/PA Pro target hppa*-*-pro*
4777 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4778 386BSD i[3456]86-*-bsd*
4779 Sequent family i[3456]86-sequent-sysv4*
4780 i[3456]86-sequent-sysv*
4781 i[3456]86-sequent-bsd*
4782 SPARC running LynxOS sparc-*-lynxos*
4783 SPARC running SunOS 4 sparc-*-sunos4*
4784 Tsqware Sparclet sparclet-*-*
4785 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4787 *** Changes in GDB 6.0:
4791 Support for debugging the Objective-C programming language has been
4792 integrated into GDB.
4794 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4796 DWARF 2's Call Frame Information makes available compiler generated
4797 information that more exactly describes the program's run-time stack.
4798 By using this information, GDB is able to provide more robust stack
4801 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4802 have been updated to use a new backtrace mechanism which includes
4803 DWARF 2 CFI support.
4807 GDB's remote protocol has been extended to include support for hosted
4808 file I/O (where the remote target uses GDB's file system). See GDB's
4809 remote protocol documentation for details.
4811 * All targets using the new architecture framework.
4813 All of GDB's targets have been updated to use the new internal
4814 architecture framework. The way is now open for future GDB releases
4815 to include cross-architecture native debugging support (i386 on amd64,
4818 * GNU/Linux's Thread Local Storage (TLS)
4820 GDB now includes support for for the GNU/Linux implementation of
4821 per-thread variables.
4823 * GNU/Linux's Native POSIX Thread Library (NPTL)
4825 GDB's thread code has been updated to work with either the new
4826 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4828 * Separate debug info.
4830 GDB, in conjunction with BINUTILS, now supports a mechanism for
4831 automatically loading debug information from a separate file. Instead
4832 of shipping full debug and non-debug versions of system libraries,
4833 system integrators can now instead ship just the stripped libraries
4834 and optional debug files.
4836 * DWARF 2 Location Expressions
4838 DWARF 2 Location Expressions allow the compiler to more completely
4839 describe the location of variables (even in optimized code) to the
4842 GDB now includes preliminary support for location expressions (support
4843 for DW_OP_piece is still missing).
4847 A number of long standing bugs that caused GDB to die while starting a
4848 Java application have been fixed. GDB's Java support is now
4849 considered "useable".
4851 * GNU/Linux support for fork, vfork, and exec.
4853 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4854 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4857 * GDB supports logging output to a file
4859 There are two new commands, "set logging" and "show logging", which can be
4860 used to capture GDB's output to a file.
4862 * The meaning of "detach" has changed for gdbserver
4864 The "detach" command will now resume the application, as documented. To
4865 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4868 * d10v, m68hc11 `regs' command deprecated
4870 The `info registers' command has been updated so that it displays the
4871 registers using a format identical to the old `regs' command.
4875 A new command, "maint set profile on/off", has been added. This command can
4876 be used to enable or disable profiling while running GDB, to profile a
4877 session or a set of commands. In addition there is a new configure switch,
4878 "--enable-profiling", which will cause GDB to be compiled with profiling
4879 data, for more informative profiling results.
4881 * Default MI syntax changed to "mi2".
4883 The default MI (machine interface) syntax, enabled by the command line
4884 option "-i=mi", has been changed to "mi2". The previous MI syntax,
4885 "mi1", can be enabled by specifying the option "-i=mi1".
4887 Support for the original "mi0" syntax (included in GDB 5.0) has been
4890 Fix for gdb/192: removed extraneous space when displaying frame level.
4891 Fix for gdb/672: update changelist is now output in mi list format.
4892 Fix for gdb/702: a -var-assign that updates the value now shows up
4893 in a subsequent -var-update.
4895 * New native configurations.
4897 FreeBSD/amd64 x86_64-*-freebsd*
4899 * Multi-arched targets.
4901 HP/PA HPUX11 hppa*-*-hpux*
4902 Renesas M32R/D w/simulator m32r-*-elf*
4904 * OBSOLETE configurations and files
4906 Configurations that have been declared obsolete in this release have
4907 been commented out. Unless there is activity to revive these
4908 configurations, the next release of GDB will have their sources
4909 permanently REMOVED.
4911 Z8000 simulator z8k-zilog-none or z8ksim
4912 Matsushita MN10200 w/simulator mn10200-*-*
4913 H8/500 simulator h8500-hitachi-hms or h8500hms
4914 HP/PA running BSD hppa*-*-bsd*
4915 HP/PA running OSF/1 hppa*-*-osf*
4916 HP/PA Pro target hppa*-*-pro*
4917 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4918 Sequent family i[3456]86-sequent-sysv4*
4919 i[3456]86-sequent-sysv*
4920 i[3456]86-sequent-bsd*
4921 Tsqware Sparclet sparclet-*-*
4922 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4924 * REMOVED configurations and files
4927 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
4928 IBM AIX PS/2 i[3456]86-*-aix
4929 i386 running Mach 3.0 i[3456]86-*-mach3*
4930 i386 running Mach i[3456]86-*-mach*
4931 i386 running OSF/1 i[3456]86-*osf1mk*
4932 HP/Apollo 68k Family m68*-apollo*-sysv*,
4934 m68*-hp-bsd*, m68*-hp-hpux*
4935 Argonaut Risc Chip (ARC) arc-*-*
4936 Mitsubishi D30V d30v-*-*
4937 Fujitsu FR30 fr30-*-elf*
4938 OS/9000 i[34]86-*-os9k
4939 I960 with MON960 i960-*-coff
4941 * MIPS $fp behavior changed
4943 The convenience variable $fp, for the MIPS, now consistently returns
4944 the address of the current frame's base. Previously, depending on the
4945 context, $fp could refer to either $sp or the current frame's base
4946 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
4947 The GNU Source-Level Debugger''.
4949 *** Changes in GDB 5.3:
4951 * GNU/Linux shared library multi-threaded performance improved.
4953 When debugging a multi-threaded application on GNU/Linux, GDB now uses
4954 `/proc', in preference to `ptrace' for memory reads. This may result
4955 in an improvement in the start-up time of multi-threaded, shared
4956 library applications when run under GDB. One GDB user writes: ``loads
4957 shared libs like mad''.
4959 * ``gdbserver'' now supports multi-threaded applications on some targets
4961 Support for debugging multi-threaded applications which use
4962 the GNU/Linux LinuxThreads package has been added for
4963 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
4964 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
4966 * GDB now supports C/C++ preprocessor macros.
4968 GDB now expands preprocessor macro invocations in C/C++ expressions,
4969 and provides various commands for showing macro definitions and how
4972 The new command `macro expand EXPRESSION' expands any macro
4973 invocations in expression, and shows the result.
4975 The new command `show macro MACRO-NAME' shows the definition of the
4976 macro named MACRO-NAME, and where it was defined.
4978 Most compilers don't include information about macros in the debugging
4979 information by default. In GCC 3.1, for example, you need to compile
4980 your program with the options `-gdwarf-2 -g3'. If the macro
4981 information is present in the executable, GDB will read it.
4983 * Multi-arched targets.
4985 DEC Alpha (partial) alpha*-*-*
4986 DEC VAX (partial) vax-*-*
4988 National Semiconductor NS32000 (partial) ns32k-*-*
4989 Motorola 68000 (partial) m68k-*-*
4990 Motorola MCORE mcore-*-*
4994 Fujitsu FRV architecture added by Red Hat frv*-*-*
4997 * New native configurations
4999 Alpha NetBSD alpha*-*-netbsd*
5000 SH NetBSD sh*-*-netbsdelf*
5001 MIPS NetBSD mips*-*-netbsd*
5002 UltraSPARC NetBSD sparc64-*-netbsd*
5004 * OBSOLETE configurations and files
5006 Configurations that have been declared obsolete in this release have
5007 been commented out. Unless there is activity to revive these
5008 configurations, the next release of GDB will have their sources
5009 permanently REMOVED.
5011 Mitsubishi D30V d30v-*-*
5012 OS/9000 i[34]86-*-os9k
5013 IBM AIX PS/2 i[3456]86-*-aix
5014 Fujitsu FR30 fr30-*-elf*
5015 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5016 Argonaut Risc Chip (ARC) arc-*-*
5017 i386 running Mach 3.0 i[3456]86-*-mach3*
5018 i386 running Mach i[3456]86-*-mach*
5019 i386 running OSF/1 i[3456]86-*osf1mk*
5020 HP/Apollo 68k Family m68*-apollo*-sysv*,
5022 m68*-hp-bsd*, m68*-hp-hpux*
5023 I960 with MON960 i960-*-coff
5025 * OBSOLETE languages
5027 CHILL, a Pascal like language used by telecommunications companies.
5029 * REMOVED configurations and files
5031 AMD 29k family via UDI a29k-amd-udi, udi29k
5032 A29K VxWorks a29k-*-vxworks
5033 AMD 29000 embedded, using EBMON a29k-none-none
5034 AMD 29000 embedded with COFF a29k-none-coff
5035 AMD 29000 embedded with a.out a29k-none-aout
5037 testsuite/gdb.hp/gdb.threads-hp/ directory
5039 * New command "set max-user-call-depth <nnn>"
5041 This command allows the user to limit the call depth of user-defined
5042 commands. The default is 1024.
5044 * Changes in FreeBSD/i386 native debugging.
5046 Support for the "generate-core-file" has been added.
5048 * New commands "dump", "append", and "restore".
5050 These commands allow data to be copied from target memory
5051 to a bfd-format or binary file (dump and append), and back
5052 from a file into memory (restore).
5054 * Improved "next/step" support on multi-processor Alpha Tru64.
5056 The previous single-step mechanism could cause unpredictable problems,
5057 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5058 of a software single-step mechanism prevents this.
5060 *** Changes in GDB 5.2.1:
5068 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5069 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5070 Fix, by Joel Brobecker imported from mainline.
5072 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5073 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5074 Fix, by Fred Fish, imported from mainline.
5076 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5077 Surprisingly enough, it works now.
5078 By Michal Ludvig, imported from mainline.
5080 i386 hardware watchpoint support:
5081 avoid misses on second run for some targets.
5082 By Pierre Muller, imported from mainline.
5084 *** Changes in GDB 5.2:
5086 * New command "set trust-readonly-sections on[off]".
5088 This command is a hint that tells gdb that read-only sections
5089 really are read-only (ie. that their contents will not change).
5090 In this mode, gdb will go to the object file rather than the
5091 target to read memory from read-only sections (such as ".text").
5092 This can be a significant performance improvement on some
5093 (notably embedded) targets.
5095 * New command "generate-core-file" (or "gcore").
5097 This new gdb command allows the user to drop a core file of the child
5098 process state at any time. So far it's been implemented only for
5099 GNU/Linux and Solaris, but should be relatively easily ported to other
5100 hosts. Argument is core file name (defaults to core.<pid>).
5102 * New command line option
5104 GDB now accepts --pid or -p followed by a process id.
5106 * Change in command line behavior -- corefiles vs. process ids.
5108 There is a subtle behavior in the way in which GDB handles
5109 command line arguments. The first non-flag argument is always
5110 a program to debug, but the second non-flag argument may either
5111 be a corefile or a process id. Previously, GDB would attempt to
5112 open the second argument as a corefile, and if that failed, would
5113 issue a superfluous error message and then attempt to attach it as
5114 a process. Now, if the second argument begins with a non-digit,
5115 it will be treated as a corefile. If it begins with a digit,
5116 GDB will attempt to attach it as a process, and if no such process
5117 is found, will then attempt to open it as a corefile.
5119 * Changes in ARM configurations.
5121 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5122 configuration is fully multi-arch.
5124 * New native configurations
5126 ARM NetBSD arm*-*-netbsd*
5127 x86 OpenBSD i[3456]86-*-openbsd*
5128 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5129 Sparc64 running FreeBSD sparc64-*-freebsd*
5133 Sanyo XStormy16 xstormy16-elf
5135 * OBSOLETE configurations and files
5137 Configurations that have been declared obsolete in this release have
5138 been commented out. Unless there is activity to revive these
5139 configurations, the next release of GDB will have their sources
5140 permanently REMOVED.
5142 AMD 29k family via UDI a29k-amd-udi, udi29k
5143 A29K VxWorks a29k-*-vxworks
5144 AMD 29000 embedded, using EBMON a29k-none-none
5145 AMD 29000 embedded with COFF a29k-none-coff
5146 AMD 29000 embedded with a.out a29k-none-aout
5148 testsuite/gdb.hp/gdb.threads-hp/ directory
5150 * REMOVED configurations and files
5152 TI TMS320C80 tic80-*-*
5154 PowerPC Solaris powerpcle-*-solaris*
5155 PowerPC Windows NT powerpcle-*-cygwin32
5156 PowerPC Netware powerpc-*-netware*
5157 Harris/CXUX m88k m88*-harris-cxux*
5158 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5159 ns32k-utek-sysv* ns32k-utek-*
5160 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5161 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5162 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5163 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5164 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5166 * Changes to command line processing
5168 The new `--args' feature can be used to specify command-line arguments
5169 for the inferior from gdb's command line.
5171 * Changes to key bindings
5173 There is a new `operate-and-get-next' function bound to `C-o'.
5175 *** Changes in GDB 5.1.1
5177 Fix compile problem on DJGPP.
5179 Fix a problem with floating-point registers on the i386 being
5182 Fix to stop GDB crashing on .debug_str debug info.
5184 Numerous documentation fixes.
5186 Numerous testsuite fixes.
5188 *** Changes in GDB 5.1:
5190 * New native configurations
5192 Alpha FreeBSD alpha*-*-freebsd*
5193 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5194 MIPS GNU/Linux mips*-*-linux*
5195 MIPS SGI Irix 6.x mips*-sgi-irix6*
5196 ia64 AIX ia64-*-aix*
5197 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5201 Motorola 68HC11 and 68HC12 m68hc11-elf
5203 UltraSparc running GNU/Linux sparc64-*-linux*
5205 * OBSOLETE configurations and files
5207 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5208 Harris/CXUX m88k m88*-harris-cxux*
5209 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5210 ns32k-utek-sysv* ns32k-utek-*
5211 TI TMS320C80 tic80-*-*
5213 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5214 PowerPC Solaris powerpcle-*-solaris*
5215 PowerPC Windows NT powerpcle-*-cygwin32
5216 PowerPC Netware powerpc-*-netware*
5217 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5218 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5219 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5220 Apple Macintosh (MPW) host N/A
5222 stuff.c (Program to stuff files into a specially prepared space in kdb)
5223 kdb-start.c (Main loop for the standalone kernel debugger)
5225 Configurations that have been declared obsolete in this release have
5226 been commented out. Unless there is activity to revive these
5227 configurations, the next release of GDB will have their sources
5228 permanently REMOVED.
5230 * REMOVED configurations and files
5232 Altos 3068 m68*-altos-*
5233 Convex c1-*-*, c2-*-*
5235 ARM RISCix arm-*-* (as host)
5239 * GDB has been converted to ISO C.
5241 GDB's source code has been converted to ISO C. In particular, the
5242 sources are fully protoized, and rely on standard headers being
5247 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5249 * The MI enabled by default.
5251 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5252 revised and enabled by default. Packages which use GDB as a debugging
5253 engine behind a UI or another front end are encouraged to switch to
5254 using the GDB/MI interface, instead of the old annotations interface
5255 which is now deprecated.
5257 * Support for debugging Pascal programs.
5259 GDB now includes support for debugging Pascal programs. The following
5260 main features are supported:
5262 - Pascal-specific data types such as sets;
5264 - automatic recognition of Pascal sources based on file-name
5267 - Pascal-style display of data types, variables, and functions;
5269 - a Pascal expression parser.
5271 However, some important features are not yet supported.
5273 - Pascal string operations are not supported at all;
5275 - there are some problems with boolean types;
5277 - Pascal type hexadecimal constants are not supported
5278 because they conflict with the internal variables format;
5280 - support for Pascal objects and classes is not full yet;
5282 - unlike Pascal, GDB is case-sensitive for symbol names.
5284 * Changes in completion.
5286 Commands such as `shell', `run' and `set args', which pass arguments
5287 to inferior programs, now complete on file names, similar to what
5288 users expect at the shell prompt.
5290 Commands which accept locations, such as `disassemble', `print',
5291 `breakpoint', `until', etc. now complete on filenames as well as
5292 program symbols. Thus, if you type "break foob TAB", and the source
5293 files linked into the programs include `foobar.c', that file name will
5294 be one of the candidates for completion. However, file names are not
5295 considered for completion after you typed a colon that delimits a file
5296 name from a name of a function in that file, as in "break foo.c:bar".
5298 `set demangle-style' completes on available demangling styles.
5300 * New platform-independent commands:
5302 It is now possible to define a post-hook for a command as well as a
5303 hook that runs before the command. For more details, see the
5304 documentation of `hookpost' in the GDB manual.
5306 * Changes in GNU/Linux native debugging.
5308 Support for debugging multi-threaded programs has been completely
5309 revised for all platforms except m68k and sparc. You can now debug as
5310 many threads as your system allows you to have.
5312 Attach/detach is supported for multi-threaded programs.
5314 Support for SSE registers was added for x86. This doesn't work for
5315 multi-threaded programs though.
5317 * Changes in MIPS configurations.
5319 Multi-arch support is enabled for all MIPS configurations.
5321 GDB can now be built as native debugger on SGI Irix 6.x systems for
5322 debugging n32 executables. (Debugging 64-bit executables is not yet
5325 * Unified support for hardware watchpoints in all x86 configurations.
5327 Most (if not all) native x86 configurations support hardware-assisted
5328 breakpoints and watchpoints in a unified manner. This support
5329 implements debug register sharing between watchpoints, which allows to
5330 put a virtually infinite number of watchpoints on the same address,
5331 and also supports watching regions up to 16 bytes with several debug
5334 The new maintenance command `maintenance show-debug-regs' toggles
5335 debugging print-outs in functions that insert, remove, and test
5336 watchpoints and hardware breakpoints.
5338 * Changes in the DJGPP native configuration.
5340 New command ``info dos sysinfo'' displays assorted information about
5341 the CPU, OS, memory, and DPMI server.
5343 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5344 display information about segment descriptors stored in GDT, LDT, and
5347 New commands ``info dos pde'' and ``info dos pte'' display entries
5348 from Page Directory and Page Tables (for now works with CWSDPMI only).
5349 New command ``info dos address-pte'' displays the Page Table entry for
5350 a given linear address.
5352 GDB can now pass command lines longer than 126 characters to the
5353 program being debugged (requires an update to the libdbg.a library
5354 which is part of the DJGPP development kit).
5356 DWARF2 debug info is now supported.
5358 It is now possible to `step' and `next' through calls to `longjmp'.
5360 * Changes in documentation.
5362 All GDB documentation was converted to GFDL, the GNU Free
5363 Documentation License.
5365 Tracepoints-related commands are now fully documented in the GDB
5368 TUI, the Text-mode User Interface, is now documented in the manual.
5370 Tracepoints-related commands are now fully documented in the GDB
5373 The "GDB Internals" manual now has an index. It also includes
5374 documentation of `ui_out' functions, GDB coding standards, x86
5375 hardware watchpoints, and memory region attributes.
5377 * GDB's version number moved to ``version.in''
5379 The Makefile variable VERSION has been replaced by the file
5380 ``version.in''. People creating GDB distributions should update the
5381 contents of this file.
5385 GUD support is now a standard part of the EMACS distribution.
5387 *** Changes in GDB 5.0:
5389 * Improved support for debugging FP programs on x86 targets
5391 Unified and much-improved support for debugging floating-point
5392 programs on all x86 targets. In particular, ``info float'' now
5393 displays the FP registers in the same format on all x86 targets, with
5394 greater level of detail.
5396 * Improvements and bugfixes in hardware-assisted watchpoints
5398 It is now possible to watch array elements, struct members, and
5399 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5400 on x86 targets no longer erroneously trigger when the address is
5403 * Improvements in the native DJGPP version of GDB
5405 The distribution now includes all the scripts and auxiliary files
5406 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5407 machines ``out of the box''.
5409 The DJGPP version can now debug programs that use signals. It is
5410 possible to catch signals that happened in the debuggee, deliver
5411 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5412 would kill the program being debugged.) Programs that hook hardware
5413 interrupts (keyboard, timer, etc.) can also be debugged.
5415 It is now possible to debug DJGPP programs that redirect their
5416 standard handles or switch them to raw (as opposed to cooked) mode, or
5417 even close them. The command ``run < foo > bar'' works as expected,
5418 and ``info terminal'' reports useful information about the debuggee's
5419 terminal, including raw/cooked mode, redirection, etc.
5421 The DJGPP version now uses termios functions for console I/O, which
5422 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5425 DOS-style file names with drive letters are now fully supported by
5428 It is now possible to debug DJGPP programs that switch their working
5429 directory. It is also possible to rerun the debuggee any number of
5430 times without restarting GDB; thus, you can use the same setup,
5431 breakpoints, etc. for many debugging sessions.
5433 * New native configurations
5435 ARM GNU/Linux arm*-*-linux*
5436 PowerPC GNU/Linux powerpc-*-linux*
5440 Motorola MCore mcore-*-*
5441 x86 VxWorks i[3456]86-*-vxworks*
5442 PowerPC VxWorks powerpc-*-vxworks*
5443 TI TMS320C80 tic80-*-*
5445 * OBSOLETE configurations
5447 Altos 3068 m68*-altos-*
5448 Convex c1-*-*, c2-*-*
5450 ARM RISCix arm-*-* (as host)
5453 Configurations that have been declared obsolete will be commented out,
5454 but the code will be left in place. If there is no activity to revive
5455 these configurations before the next release of GDB, the sources will
5456 be permanently REMOVED.
5458 * Gould support removed
5460 Support for the Gould PowerNode and NP1 has been removed.
5462 * New features for SVR4
5464 On SVR4 native platforms (such as Solaris), if you attach to a process
5465 without first loading a symbol file, GDB will now attempt to locate and
5466 load symbols from the running process's executable file.
5468 * Many C++ enhancements
5470 C++ support has been greatly improved. Overload resolution now works properly
5471 in almost all cases. RTTI support is on the way.
5473 * Remote targets can connect to a sub-program
5475 A popen(3) style serial-device has been added. This device starts a
5476 sub-process (such as a stand-alone simulator) and then communicates
5477 with that. The sub-program to run is specified using the syntax
5478 ``|<program> <args>'' vis:
5480 (gdb) set remotedebug 1
5481 (gdb) target extended-remote |mn10300-elf-sim program-args
5483 * MIPS 64 remote protocol
5485 A long standing bug in the mips64 remote protocol where by GDB
5486 expected certain 32 bit registers (ex SR) to be transfered as 32
5487 instead of 64 bits has been fixed.
5489 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5490 added to provide backward compatibility with older versions of GDB.
5492 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5494 The command ``set remotebinarydownload'' command has been replaced by
5495 ``set remote X-packet''. Other commands in ``set remote'' family
5496 include ``set remote P-packet''.
5498 * Breakpoint commands accept ranges.
5500 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5501 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5502 ``tracepoint passcount'' also accepts a range of tracepoints.
5504 * ``apropos'' command added.
5506 The ``apropos'' command searches through command names and
5507 documentation strings, printing out matches, making it much easier to
5508 try to find a command that does what you are looking for.
5512 A new machine oriented interface (MI) has been added to GDB. This
5513 interface is designed for debug environments running GDB as a separate
5514 process. This is part of the long term libGDB project. See the
5515 "GDB/MI" chapter of the GDB manual for further information. It can be
5516 enabled by configuring with:
5518 .../configure --enable-gdbmi
5520 *** Changes in GDB-4.18:
5522 * New native configurations
5524 HP-UX 10.20 hppa*-*-hpux10.20
5525 HP-UX 11.x hppa*-*-hpux11.0*
5526 M68K GNU/Linux m68*-*-linux*
5530 Fujitsu FR30 fr30-*-elf*
5531 Intel StrongARM strongarm-*-*
5532 Mitsubishi D30V d30v-*-*
5534 * OBSOLETE configurations
5536 Gould PowerNode, NP1 np1-*-*, pn-*-*
5538 Configurations that have been declared obsolete will be commented out,
5539 but the code will be left in place. If there is no activity to revive
5540 these configurations before the next release of GDB, the sources will
5541 be permanently REMOVED.
5545 As a compatibility experiment, GDB's source files buildsym.h and
5546 buildsym.c have been converted to pure standard C, no longer
5547 containing any K&R compatibility code. We believe that all systems in
5548 use today either come with a standard C compiler, or have a GCC port
5549 available. If this is not true, please report the affected
5550 configuration to bug-gdb@gnu.org immediately. See the README file for
5551 information about getting a standard C compiler if you don't have one
5556 GDB now uses readline 2.2.
5558 * set extension-language
5560 You can now control the mapping between filename extensions and source
5561 languages by using the `set extension-language' command. For instance,
5562 you can ask GDB to treat .c files as C++ by saying
5563 set extension-language .c c++
5564 The command `info extensions' lists all of the recognized extensions
5565 and their associated languages.
5567 * Setting processor type for PowerPC and RS/6000
5569 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5570 you can use the `set processor' command to specify what variant of the
5571 PowerPC family you are debugging. The command
5575 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5576 following PowerPC and RS6000 variants:
5578 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5579 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5581 403GC IBM PowerPC 403GC
5582 505 Motorola PowerPC 505
5583 860 Motorola PowerPC 860 or 850
5584 601 Motorola PowerPC 601
5585 602 Motorola PowerPC 602
5586 603 Motorola/IBM PowerPC 603 or 603e
5587 604 Motorola PowerPC 604 or 604e
5588 750 Motorola/IBM PowerPC 750 or 750
5590 At the moment, this command just tells GDB what to name the
5591 special-purpose processor registers. Since almost all the affected
5592 registers are inaccessible to user-level programs, this command is
5593 only useful for remote debugging in its present form.
5597 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5598 more extensive support for HP-UX. Added features include shared
5599 library support, kernel threads and hardware watchpoints for 11.00,
5600 support for HP's ANSI C and C++ compilers, and a compatibility mode
5601 for xdb and dbx commands.
5605 HP's donation includes the new concept of catchpoints, which is a
5606 generalization of the old catch command. On HP-UX, it is now possible
5607 to catch exec, fork, and vfork, as well as library loading.
5609 This means that the existing catch command has changed; its first
5610 argument now specifies the type of catch to be set up. See the
5611 output of "help catch" for a list of catchpoint types.
5613 * Debugging across forks
5615 On HP-UX, you can choose which process to debug when a fork() happens
5620 HP has donated a curses-based terminal user interface (TUI). To get
5621 it, build with --enable-tui. Although this can be enabled for any
5622 configuration, at present it only works for native HP debugging.
5624 * GDB remote protocol additions
5626 A new protocol packet 'X' that writes binary data is now available.
5627 Default behavior is to try 'X', then drop back to 'M' if the stub
5628 fails to respond. The settable variable `remotebinarydownload'
5629 allows explicit control over the use of 'X'.
5631 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5632 full 64-bit address. The command
5634 set remoteaddresssize 32
5636 can be used to revert to the old behaviour. For existing remote stubs
5637 the change should not be noticed, as the additional address information
5640 In order to assist in debugging stubs, you may use the maintenance
5641 command `packet' to send any text string to the stub. For instance,
5643 maint packet heythere
5645 sends the packet "$heythere#<checksum>". Note that it is very easy to
5646 disrupt a debugging session by sending the wrong packet at the wrong
5649 The compare-sections command allows you to compare section data on the
5650 target to what is in the executable file without uploading or
5651 downloading, by comparing CRC checksums.
5653 * Tracing can collect general expressions
5655 You may now collect general expressions at tracepoints. This requires
5656 further additions to the target-side stub; see tracepoint.c and
5657 doc/agentexpr.texi for further details.
5659 * mask-address variable for Mips
5661 For Mips targets, you may control the zeroing of the upper 32 bits of
5662 a 64-bit address by entering `set mask-address on'. This is mainly
5663 of interest to users of embedded R4xxx and R5xxx processors.
5665 * Higher serial baud rates
5667 GDB's serial code now allows you to specify baud rates 57600, 115200,
5668 230400, and 460800 baud. (Note that your host system may not be able
5669 to achieve all of these rates.)
5673 The i960 configuration now includes an initial implementation of a
5674 builtin simulator, contributed by Jim Wilson.
5677 *** Changes in GDB-4.17:
5679 * New native configurations
5681 Alpha GNU/Linux alpha*-*-linux*
5682 Unixware 2.x i[3456]86-unixware2*
5683 Irix 6.x mips*-sgi-irix6*
5684 PowerPC GNU/Linux powerpc-*-linux*
5685 PowerPC Solaris powerpcle-*-solaris*
5686 Sparc GNU/Linux sparc-*-linux*
5687 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5691 Argonaut Risc Chip (ARC) arc-*-*
5692 Hitachi H8/300S h8300*-*-*
5693 Matsushita MN10200 w/simulator mn10200-*-*
5694 Matsushita MN10300 w/simulator mn10300-*-*
5695 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5696 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5697 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5698 Mitsubishi D10V w/simulator d10v-*-*
5699 Mitsubishi M32R/D w/simulator m32r-*-elf*
5700 Tsqware Sparclet sparclet-*-*
5701 NEC V850 w/simulator v850-*-*
5703 * New debugging protocols
5705 ARM with RDI protocol arm*-*-*
5706 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5707 DDB and LSI variants of PMON protocol mips*-*-*
5708 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5709 PowerPC with SDS protocol powerpc{,le}-*-eabi
5710 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5714 All configurations can now understand and use the DWARF 2 debugging
5715 format. The choice is automatic, if the symbol file contains DWARF 2
5720 GDB now includes basic Java language support. This support is
5721 only useful with Java compilers that produce native machine code.
5723 * solib-absolute-prefix and solib-search-path
5725 For SunOS and SVR4 shared libraries, you may now set the prefix for
5726 loading absolute shared library symbol files, and the search path for
5727 locating non-absolute shared library symbol files.
5729 * Live range splitting
5731 GDB can now effectively debug code for which GCC has performed live
5732 range splitting as part of its optimization. See gdb/doc/LRS for
5733 more details on the expected format of the stabs information.
5737 GDB's support for the GNU Hurd, including thread debugging, has been
5738 updated to work with current versions of the Hurd.
5742 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5743 instruction set. ARM GDB automatically detects when Thumb
5744 instructions are in use, and adjusts disassembly and backtracing
5749 GDB's MIPS target configurations now handle the MIP16 16-bit
5754 GDB now includes support for overlays; if an executable has been
5755 linked such that multiple sections are based at the same address, GDB
5756 will decide which section to use for symbolic info. You can choose to
5757 control the decision manually, using overlay commands, or implement
5758 additional target-side support and use "overlay load-target" to bring
5759 in the overlay mapping. Do "help overlay" for more detail.
5763 The command "info symbol <address>" displays information about
5764 the symbol at the specified address.
5768 The standard remote protocol now includes an extension that allows
5769 asynchronous collection and display of trace data. This requires
5770 extensive support in the target-side debugging stub. Tracing mode
5771 includes a new interaction mode in GDB and new commands: see the
5772 file tracepoint.c for more details.
5776 Configurations for embedded MIPS now include a simulator contributed
5777 by Cygnus Solutions. The simulator supports the instruction sets
5778 of most MIPS variants.
5782 Sparc configurations may now include the ERC32 simulator contributed
5783 by the European Space Agency. The simulator is not built into
5784 Sparc targets by default; configure with --enable-sim to include it.
5788 For target configurations that may include multiple variants of a
5789 basic architecture (such as MIPS and SH), you may now set the
5790 architecture explicitly. "set arch" sets, "info arch" lists
5791 the possible architectures.
5793 *** Changes in GDB-4.16:
5795 * New native configurations
5797 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5798 M68K NetBSD m68k-*-netbsd*
5799 PowerPC AIX 4.x powerpc-*-aix*
5800 PowerPC MacOS powerpc-*-macos*
5801 PowerPC Windows NT powerpcle-*-cygwin32
5802 RS/6000 AIX 4.x rs6000-*-aix4*
5806 ARM with RDP protocol arm-*-*
5807 I960 with MON960 i960-*-coff
5808 MIPS VxWorks mips*-*-vxworks*
5809 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5810 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5812 Matra Sparclet sparclet-*-*
5816 The powerpc-eabi configuration now includes the PSIM simulator,
5817 contributed by Andrew Cagney, with assistance from Mike Meissner.
5818 PSIM is a very elaborate model of the PowerPC, including not only
5819 basic instruction set execution, but also details of execution unit
5820 performance and I/O hardware. See sim/ppc/README for more details.
5824 GDB now works with Solaris 2.5.
5826 * Windows 95/NT native
5828 GDB will now work as a native debugger on Windows 95 and Windows NT.
5829 To build it from source, you must use the "gnu-win32" environment,
5830 which uses a DLL to emulate enough of Unix to run the GNU tools.
5831 Further information, binaries, and sources are available at
5832 ftp.cygnus.com, under pub/gnu-win32.
5834 * dont-repeat command
5836 If a user-defined command includes the command `dont-repeat', then the
5837 command will not be repeated if the user just types return. This is
5838 useful if the command is time-consuming to run, so that accidental
5839 extra keystrokes don't run the same command many times.
5841 * Send break instead of ^C
5843 The standard remote protocol now includes an option to send a break
5844 rather than a ^C to the target in order to interrupt it. By default,
5845 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5847 * Remote protocol timeout
5849 The standard remote protocol includes a new variable `remotetimeout'
5850 that allows you to set the number of seconds before GDB gives up trying
5851 to read from the target. The default value is 2.
5853 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5855 By default GDB will automatically keep track of objects as they are
5856 loaded and unloaded by the dynamic linker. By using the command `set
5857 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5858 when shared library events occur, thus allowing you to set breakpoints
5859 in shared libraries which are explicitly loaded by the inferior.
5861 Note this feature does not work on hpux8. On hpux9 you must link
5862 /usr/lib/end.o into your program. This feature should work
5863 automatically on hpux10.
5865 * Irix 5.x hardware watchpoint support
5867 Irix 5 configurations now support the use of hardware watchpoints.
5869 * Mips protocol "SYN garbage limit"
5871 When debugging a Mips target using the `target mips' protocol, you
5872 may set the number of characters that GDB will ignore by setting
5873 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5874 every character. The default value is 1050.
5876 * Recording and replaying remote debug sessions
5878 If you set `remotelogfile' to the name of a file, gdb will write to it
5879 a recording of a remote debug session. This recording may then be
5880 replayed back to gdb using "gdbreplay". See gdbserver/README for
5881 details. This is useful when you have a problem with GDB while doing
5882 remote debugging; you can make a recording of the session and send it
5883 to someone else, who can then recreate the problem.
5885 * Speedups for remote debugging
5887 GDB includes speedups for downloading and stepping MIPS systems using
5888 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
5889 and more efficient S-record downloading.
5891 * Memory use reductions and statistics collection
5893 GDB now uses less memory and reports statistics about memory usage.
5894 Try the `maint print statistics' command, for example.
5896 *** Changes in GDB-4.15:
5898 * Psymtabs for XCOFF
5900 The symbol reader for AIX GDB now uses partial symbol tables. This
5901 can greatly improve startup time, especially for large executables.
5903 * Remote targets use caching
5905 Remote targets now use a data cache to speed up communication with the
5906 remote side. The data cache could lead to incorrect results because
5907 it doesn't know about volatile variables, thus making it impossible to
5908 debug targets which use memory mapped I/O devices. `set remotecache
5909 off' turns the the data cache off.
5911 * Remote targets may have threads
5913 The standard remote protocol now includes support for multiple threads
5914 in the target system, using new protocol commands 'H' and 'T'. See
5915 gdb/remote.c for details.
5919 If GDB is configured with `--enable-netrom', then it will include
5920 support for the NetROM ROM emulator from XLNT Designs. The NetROM
5921 acts as though it is a bank of ROM on the target board, but you can
5922 write into it over the network. GDB's support consists only of
5923 support for fast loading into the emulated ROM; to debug, you must use
5924 another protocol, such as standard remote protocol. The usual
5925 sequence is something like
5927 target nrom <netrom-hostname>
5929 target remote <netrom-hostname>:1235
5933 GDB now includes support for the Apple Macintosh, as a host only. It
5934 may be run as either an MPW tool or as a standalone application, and
5935 it can debug through the serial port. All the usual GDB commands are
5936 available, but to the target command, you must supply "serial" as the
5937 device type instead of "/dev/ttyXX". See mpw-README in the main
5938 directory for more information on how to build. The MPW configuration
5939 scripts */mpw-config.in support only a few targets, and only the
5940 mips-idt-ecoff target has been tested.
5944 GDB configuration now uses autoconf. This is not user-visible,
5945 but does simplify configuration and building.
5949 GDB now supports hpux10.
5951 *** Changes in GDB-4.14:
5953 * New native configurations
5955 x86 FreeBSD i[345]86-*-freebsd
5956 x86 NetBSD i[345]86-*-netbsd
5957 NS32k NetBSD ns32k-*-netbsd
5958 Sparc NetBSD sparc-*-netbsd
5962 A29K VxWorks a29k-*-vxworks
5963 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
5964 CPU32 EST-300 emulator m68*-*-est*
5965 PowerPC ELF powerpc-*-elf
5968 * Alpha OSF/1 support for procfs
5970 GDB now supports procfs under OSF/1-2.x and higher, which makes it
5971 possible to attach to running processes. As the mounting of the /proc
5972 filesystem is optional on the Alpha, GDB automatically determines
5973 the availability of /proc during startup. This can lead to problems
5974 if /proc is unmounted after GDB has been started.
5976 * Arguments to user-defined commands
5978 User commands may accept up to 10 arguments separated by whitespace.
5979 Arguments are accessed within the user command via $arg0..$arg9. A
5982 print $arg0 + $arg1 + $arg2
5984 To execute the command use:
5987 Defines the command "adder" which prints the sum of its three arguments.
5988 Note the arguments are text substitutions, so they may reference variables,
5989 use complex expressions, or even perform inferior function calls.
5991 * New `if' and `while' commands
5993 This makes it possible to write more sophisticated user-defined
5994 commands. Both commands take a single argument, which is the
5995 expression to evaluate, and must be followed by the commands to
5996 execute, one per line, if the expression is nonzero, the list being
5997 terminated by the word `end'. The `if' command list may include an
5998 `else' word, which causes the following commands to be executed only
5999 if the expression is zero.
6001 * Fortran source language mode
6003 GDB now includes partial support for Fortran 77. It will recognize
6004 Fortran programs and can evaluate a subset of Fortran expressions, but
6005 variables and functions may not be handled correctly. GDB will work
6006 with G77, but does not yet know much about symbols emitted by other
6009 * Better HPUX support
6011 Most debugging facilities now work on dynamic executables for HPPAs
6012 running hpux9 or later. You can attach to running dynamically linked
6013 processes, but by default the dynamic libraries will be read-only, so
6014 for instance you won't be able to put breakpoints in them. To change
6015 that behavior do the following before running the program:
6021 This will cause the libraries to be mapped private and read-write.
6022 To revert to the normal behavior, do this:
6028 You cannot set breakpoints or examine data in the library until after
6029 the library is loaded if the function/data symbols do not have
6032 GDB can now also read debug symbols produced by the HP C compiler on
6033 HPPAs (sorry, no C++, Fortran or 68k support).
6035 * Target byte order now dynamically selectable
6037 You can choose which byte order to use with a target system, via the
6038 commands "set endian big" and "set endian little", and you can see the
6039 current setting by using "show endian". You can also give the command
6040 "set endian auto", in which case GDB will use the byte order
6041 associated with the executable. Currently, only embedded MIPS
6042 configurations support dynamic selection of target byte order.
6044 * New DOS host serial code
6046 This version uses DPMI interrupts to handle buffered I/O, so you
6047 no longer need to run asynctsr when debugging boards connected to
6050 *** Changes in GDB-4.13:
6052 * New "complete" command
6054 This lists all the possible completions for the rest of the line, if it
6055 were to be given as a command itself. This is intended for use by emacs.
6057 * Trailing space optional in prompt
6059 "set prompt" no longer adds a space for you after the prompt you set. This
6060 allows you to set a prompt which ends in a space or one that does not.
6062 * Breakpoint hit counts
6064 "info break" now displays a count of the number of times the breakpoint
6065 has been hit. This is especially useful in conjunction with "ignore"; you
6066 can ignore a large number of breakpoint hits, look at the breakpoint info
6067 to see how many times the breakpoint was hit, then run again, ignoring one
6068 less than that number, and this will get you quickly to the last hit of
6071 * Ability to stop printing at NULL character
6073 "set print null-stop" will cause GDB to stop printing the characters of
6074 an array when the first NULL is encountered. This is useful when large
6075 arrays actually contain only short strings.
6077 * Shared library breakpoints
6079 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6080 breakpoints in shared libraries before the executable is run.
6082 * Hardware watchpoints
6084 There is a new hardware breakpoint for the watch command for sparclite
6085 targets. See gdb/sparclite/hw_breakpoint.note.
6087 Hardware watchpoints are also now supported under GNU/Linux.
6091 Annotations have been added. These are for use with graphical interfaces,
6092 and are still experimental. Currently only gdba.el uses these.
6094 * Improved Irix 5 support
6096 GDB now works properly with Irix 5.2.
6098 * Improved HPPA support
6100 GDB now works properly with the latest GCC and GAS.
6102 * New native configurations
6104 Sequent PTX4 i[34]86-sequent-ptx4
6105 HPPA running OSF/1 hppa*-*-osf*
6106 Atari TT running SVR4 m68*-*-sysv4*
6107 RS/6000 LynxOS rs6000-*-lynxos*
6111 OS/9000 i[34]86-*-os9k
6112 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6115 * Hitachi SH7000 and E7000-PC ICE support
6117 There is now support for communicating with the Hitachi E7000-PC ICE.
6118 This is available automatically when GDB is configured for the SH.
6122 As usual, a variety of small fixes and improvements, both generic
6123 and configuration-specific. See the ChangeLog for more detail.
6125 *** Changes in GDB-4.12:
6127 * Irix 5 is now supported
6131 GDB-4.12 on the HPPA has a number of changes which make it unable
6132 to debug the output from the currently released versions of GCC and
6133 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6134 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6135 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6138 *** Changes in GDB-4.11:
6140 * User visible changes:
6144 The "set remotedebug" option is now consistent between the mips remote
6145 target, remote targets using the gdb-specific protocol, UDI (AMD's
6146 debug protocol for the 29k) and the 88k bug monitor. It is now an
6147 integer specifying a debug level (normally 0 or 1, but 2 means more
6148 debugging info for the mips target).
6150 * DEC Alpha native support
6152 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6153 debug info, but GDB works fairly well with the DEC compiler and should
6154 work with a future GCC release. See the README file for a few
6155 Alpha-specific notes.
6157 * Preliminary thread implementation
6159 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6161 * LynxOS native and target support for 386
6163 This release has been hosted on LynxOS 2.2, and also can be configured
6164 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6167 * Improvements in C++ mangling/demangling.
6169 This release has much better g++ debugging, specifically in name
6170 mangling/demangling, virtual function calls, print virtual table,
6171 call methods, ...etc.
6173 *** Changes in GDB-4.10:
6175 * User visible changes:
6177 Remote debugging using the GDB-specific (`target remote') protocol now
6178 supports the `load' command. This is only useful if you have some
6179 other way of getting the stub to the target system, and you can put it
6180 somewhere in memory where it won't get clobbered by the download.
6182 Filename completion now works.
6184 When run under emacs mode, the "info line" command now causes the
6185 arrow to point to the line specified. Also, "info line" prints
6186 addresses in symbolic form (as well as hex).
6188 All vxworks based targets now support a user settable option, called
6189 vxworks-timeout. This option represents the number of seconds gdb
6190 should wait for responses to rpc's. You might want to use this if
6191 your vxworks target is, perhaps, a slow software simulator or happens
6192 to be on the far side of a thin network line.
6196 This release contains support for using a DEC alpha as a GDB host for
6197 cross debugging. Native alpha debugging is not supported yet.
6200 *** Changes in GDB-4.9:
6204 This is the first GDB release which is accompanied by a matching testsuite.
6205 The testsuite requires installation of dejagnu, which should be available
6206 via ftp from most sites that carry GNU software.
6210 'Cfront' style demangling has had its name changed to 'ARM' style, to
6211 emphasize that it was written from the specifications in the C++ Annotated
6212 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6213 disclaimers, it still generated too much confusion with users attempting to
6214 use gdb with AT&T cfront.
6218 GDB now uses a standard remote interface to a simulator library.
6219 So far, the library contains simulators for the Zilog Z8001/2, the
6220 Hitachi H8/300, H8/500 and Super-H.
6222 * New targets supported
6224 H8/300 simulator h8300-hitachi-hms or h8300hms
6225 H8/500 simulator h8500-hitachi-hms or h8500hms
6226 SH simulator sh-hitachi-hms or sh
6227 Z8000 simulator z8k-zilog-none or z8ksim
6228 IDT MIPS board over serial line mips-idt-ecoff
6230 Cross-debugging to GO32 targets is supported. It requires a custom
6231 version of the i386-stub.c module which is integrated with the
6232 GO32 memory extender.
6234 * New remote protocols
6236 MIPS remote debugging protocol.
6238 * New source languages supported
6240 This version includes preliminary support for Chill, a Pascal like language
6241 used by telecommunications companies. Chill support is also being integrated
6242 into the GNU compiler, but we don't know when it will be publically available.
6245 *** Changes in GDB-4.8:
6247 * HP Precision Architecture supported
6249 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6250 version of this support was available as a set of patches from the
6251 University of Utah. GDB does not support debugging of programs
6252 compiled with the HP compiler, because HP will not document their file
6253 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6254 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6256 Many problems in the preliminary version have been fixed.
6258 * Faster and better demangling
6260 We have improved template demangling and fixed numerous bugs in the GNU style
6261 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6262 character types (wchar_t) are now supported. Demangling of each symbol is now
6263 only done once, and is cached when the symbol table for a file is read in.
6264 This results in a small increase in memory usage for C programs, a moderate
6265 increase in memory usage for C++ programs, and a fantastic speedup in
6268 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6269 from the specifications in the Annotated Reference Manual, which AT&T's
6270 compiler does not actually implement.
6272 * G++ multiple inheritance compiler problem
6274 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6275 inheritance lattices was reworked to properly discover ambiguities. We
6276 recently found an example which causes this new algorithm to fail in a
6277 very subtle way, producing bad debug information for those classes.
6278 The file 'gcc.patch' (in this directory) can be applied to gcc to
6279 circumvent the problem. A future GCC release will contain a complete
6282 The previous G++ debug info problem (mentioned below for the gdb-4.7
6283 release) is fixed in gcc version 2.3.2.
6285 * Improved configure script
6287 The `configure' script will now attempt to guess your system type if
6288 you don't supply a host system type. The old scheme of supplying a
6289 host system triplet is preferable over using this. All the magic is
6290 done in the new `config.guess' script. Examine it for details.
6292 We have also brought our configure script much more in line with the FSF's
6293 version. It now supports the --with-xxx options. In particular,
6294 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6295 The resulting GDB will not be able to read arbitrary object file formats --
6296 only the format ``expected'' to be used on the configured target system.
6297 We hope to make this the default in a future release.
6299 * Documentation improvements
6301 There's new internal documentation on how to modify GDB, and how to
6302 produce clean changes to the code. We implore people to read it
6303 before submitting changes.
6305 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6306 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6307 `info' files are also provided. To build `info' files from scratch,
6308 you will need the latest `makeinfo' release, which will be available in
6309 a future texinfo-X.Y release.
6311 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6312 We're not sure exactly which versions have this problem, but it has
6313 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6314 or better. If that isn't possible, there is a patch in
6315 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6316 around this problem.
6320 GDB now supports array constants that can be used in expressions typed in by
6321 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6322 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6325 The new directory `gdb/sparclite' contains a program that demonstrates
6326 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6328 * New native hosts supported
6330 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6331 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6333 * New targets supported
6335 AMD 29k family via UDI a29k-amd-udi or udi29k
6337 * New file formats supported
6339 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6340 HPUX core files, and SCO 3.2v2 core files.
6344 Attaching to processes now works again; thanks for the many bug reports.
6346 We have also stomped on a bunch of core dumps caused by
6347 printf_filtered("%s") problems.
6349 We eliminated a copyright problem on the rpc and ptrace header files
6350 for VxWorks, which was discovered at the last minute during the 4.7
6351 release. You should now be able to build a VxWorks GDB.
6353 You can now interrupt gdb while an attached process is running. This
6354 will cause the attached process to stop, and give control back to GDB.
6356 We fixed problems caused by using too many file descriptors
6357 for reading symbols from object files and libraries. This was
6358 especially a problem for programs that used many (~100) shared
6361 The `step' command now only enters a subroutine if there is line number
6362 information for the subroutine. Otherwise it acts like the `next'
6363 command. Previously, `step' would enter subroutines if there was
6364 any debugging information about the routine. This avoids problems
6365 when using `cc -g1' on MIPS machines.
6367 * Internal improvements
6369 GDB's internal interfaces have been improved to make it easier to support
6370 debugging of multiple languages in the future.
6372 GDB now uses a common structure for symbol information internally.
6373 Minimal symbols (derived from linkage symbols in object files), partial
6374 symbols (from a quick scan of debug information), and full symbols
6375 contain a common subset of information, making it easier to write
6376 shared code that handles any of them.
6378 * New command line options
6380 We now accept --silent as an alias for --quiet.
6384 The memory-mapped-malloc library is now licensed under the GNU Library
6385 General Public License.
6387 *** Changes in GDB-4.7:
6389 * Host/native/target split
6391 GDB has had some major internal surgery to untangle the support for
6392 hosts and remote targets. Now, when you configure GDB for a remote
6393 target, it will no longer load in all of the support for debugging
6394 local programs on the host. When fully completed and tested, this will
6395 ensure that arbitrary host/target combinations are possible.
6397 The primary conceptual shift is to separate the non-portable code in
6398 GDB into three categories. Host specific code is required any time GDB
6399 is compiled on that host, regardless of the target. Target specific
6400 code relates to the peculiarities of the target, but can be compiled on
6401 any host. Native specific code is everything else: it can only be
6402 built when the host and target are the same system. Child process
6403 handling and core file support are two common `native' examples.
6405 GDB's use of /proc for controlling Unix child processes is now cleaner.
6406 It has been split out into a single module under the `target_ops' vector,
6407 plus two native-dependent functions for each system that uses /proc.
6409 * New hosts supported
6411 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6412 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6413 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6415 * New targets supported
6417 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6418 68030 and CPU32 m68030-*-*, m68332-*-*
6420 * New native hosts supported
6422 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6423 (386bsd is not well tested yet)
6424 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6426 * New file formats supported
6428 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6429 supports reading of `a.out.adobe' object files, which are an a.out
6430 format extended with minimal information about multiple sections.
6434 `show copying' is the same as the old `info copying'.
6435 `show warranty' is the same as `info warrantee'.
6436 These were renamed for consistency. The old commands continue to work.
6438 `info handle' is a new alias for `info signals'.
6440 You can now define pre-command hooks, which attach arbitrary command
6441 scripts to any command. The commands in the hook will be executed
6442 prior to the user's command. You can also create a hook which will be
6443 executed whenever the program stops. See gdb.texinfo.
6447 We now deal with Cfront style name mangling, and can even extract type
6448 info from mangled symbols. GDB can automatically figure out which
6449 symbol mangling style your C++ compiler uses.
6451 Calling of methods and virtual functions has been improved as well.
6455 The crash that occured when debugging Sun Ansi-C compiled binaries is
6456 fixed. This was due to mishandling of the extra N_SO stabs output
6459 We also finally got Ultrix 4.2 running in house, and fixed core file
6460 support, with help from a dozen people on the net.
6462 John M. Farrell discovered that the reason that single-stepping was so
6463 slow on all of the Mips based platforms (primarily SGI and DEC) was
6464 that we were trying to demangle and lookup a symbol used for internal
6465 purposes on every instruction that was being stepped through. Changing
6466 the name of that symbol so that it couldn't be mistaken for a C++
6467 mangled symbol sped things up a great deal.
6469 Rich Pixley sped up symbol lookups in general by getting much smarter
6470 about when C++ symbol mangling is necessary. This should make symbol
6471 completion (TAB on the command line) much faster. It's not as fast as
6472 we'd like, but it's significantly faster than gdb-4.6.
6476 A new user controllable variable 'call_scratch_address' can
6477 specify the location of a scratch area to be used when GDB
6478 calls a function in the target. This is necessary because the
6479 usual method of putting the scratch area on the stack does not work
6480 in systems that have separate instruction and data spaces.
6482 We integrated changes to support the 29k UDI (Universal Debugger
6483 Interface), but discovered at the last minute that we didn't have all
6484 of the appropriate copyright paperwork. We are working with AMD to
6485 resolve this, and hope to have it available soon.
6489 We have sped up the remote serial line protocol, especially for targets
6490 with lots of registers. It now supports a new `expedited status' ('T')
6491 message which can be used in place of the existing 'S' status message.
6492 This allows the remote stub to send only the registers that GDB
6493 needs to make a quick decision about single-stepping or conditional
6494 breakpoints, eliminating the need to fetch the entire register set for
6495 each instruction being stepped through.
6497 The GDB remote serial protocol now implements a write-through cache for
6498 registers, only re-reading the registers if the target has run.
6500 There is also a new remote serial stub for SPARC processors. You can
6501 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6502 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6503 processor with a serial port.
6507 Configure.in files have become much easier to read and modify. A new
6508 `table driven' format makes it more obvious what configurations are
6509 supported, and what files each one uses.
6513 There is a new opcodes library which will eventually contain all of the
6514 disassembly routines and opcode tables. At present, it only contains
6515 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6516 disassembler (binutils/objdump) to share these routines.
6518 The libiberty library is now copylefted under the GNU Library General
6519 Public License. This allows more liberal use, and was done so libg++
6520 can use it. This makes no difference to GDB, since the Library License
6521 grants all the rights from the General Public License.
6525 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6526 reference to the stabs symbol info used by the debugger. It is (as far
6527 as we know) the only published document on this fascinating topic. We
6528 encourage you to read it, compare it to the stabs information on your
6529 system, and send improvements on the document in general (to
6530 bug-gdb@prep.ai.mit.edu).
6532 And, of course, many bugs have been fixed.
6535 *** Changes in GDB-4.6:
6537 * Better support for C++ function names
6539 GDB now accepts as input the "demangled form" of C++ overloaded function
6540 names and member function names, and can do command completion on such names
6541 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6542 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6543 Make use of command completion, it is your friend.
6545 GDB also now accepts a variety of C++ mangled symbol formats. They are
6546 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6547 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6548 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6549 for the list of formats.
6551 * G++ symbol mangling problem
6553 Recent versions of gcc have a bug in how they emit debugging information for
6554 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6555 directory) can be applied to gcc to fix the problem. Alternatively, if you
6556 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6557 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6558 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6561 * New 'maintenance' command
6563 All of the commands related to hacking GDB internals have been moved out of
6564 the main command set, and now live behind the 'maintenance' command. This
6565 can also be abbreviated as 'mt'. The following changes were made:
6567 dump-me -> maintenance dump-me
6568 info all-breakpoints -> maintenance info breakpoints
6569 printmsyms -> maintenance print msyms
6570 printobjfiles -> maintenance print objfiles
6571 printpsyms -> maintenance print psymbols
6572 printsyms -> maintenance print symbols
6574 The following commands are new:
6576 maintenance demangle Call internal GDB demangler routine to
6577 demangle a C++ link name and prints the result.
6578 maintenance print type Print a type chain for a given symbol
6580 * Change to .gdbinit file processing
6582 We now read the $HOME/.gdbinit file before processing the argv arguments
6583 (e.g. reading symbol files or core files). This allows global parameters to
6584 be set, which will apply during the symbol reading. The ./.gdbinit is still
6585 read after argv processing.
6587 * New hosts supported
6589 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6591 GNU/Linux support i386-unknown-linux or linux
6593 We are also including code to support the HP/PA running BSD and HPUX. This
6594 is almost guaranteed not to work, as we didn't have time to test or build it
6595 for this release. We are including it so that the more adventurous (or
6596 masochistic) of you can play with it. We also had major problems with the
6597 fact that the compiler that we got from HP doesn't support the -g option.
6600 * New targets supported
6602 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6604 * More smarts about finding #include files
6606 GDB now remembers the compilation directory for all include files, and for
6607 all files from which C is generated (like yacc and lex sources). This
6608 greatly improves GDB's ability to find yacc/lex sources, and include files,
6609 especially if you are debugging your program from a directory different from
6610 the one that contains your sources.
6612 We also fixed a bug which caused difficulty with listing and setting
6613 breakpoints in include files which contain C code. (In the past, you had to
6614 try twice in order to list an include file that you hadn't looked at before.)
6616 * Interesting infernals change
6618 GDB now deals with arbitrary numbers of sections, where the symbols for each
6619 section must be relocated relative to that section's landing place in the
6620 target's address space. This work was needed to support ELF with embedded
6621 stabs used by Solaris-2.0.
6623 * Bug fixes (of course!)
6625 There have been loads of fixes for the following things:
6626 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6627 i960, stabs, DOS(GO32), procfs, etc...
6629 See the ChangeLog for details.
6631 *** Changes in GDB-4.5:
6633 * New machines supported (host and target)
6635 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6637 SGI Irix-4.x mips-sgi-irix4 or iris4
6639 * New malloc package
6641 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6642 Mmalloc is capable of handling mutiple heaps of memory. It is also
6643 capable of saving a heap to a file, and then mapping it back in later.
6644 This can be used to greatly speedup the startup of GDB by using a
6645 pre-parsed symbol table which lives in a mmalloc managed heap. For
6646 more details, please read mmalloc/mmalloc.texi.
6650 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6651 'help info proc' for details.
6653 * MIPS ecoff symbol table format
6655 The code that reads MIPS symbol table format is now supported on all hosts.
6656 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6659 * File name changes for MS-DOS
6661 Many files in the config directories have been renamed to make it easier to
6662 support GDB on MS-DOSe systems (which have very restrictive file name
6663 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6664 environment) is close to working but has some remaining problems. Note
6665 that debugging of DOS programs is not supported, due to limitations
6666 in the ``operating system'', but it can be used to host cross-debugging.
6668 * Cross byte order fixes
6670 Many fixes have been made to support cross debugging of Sparc and MIPS
6671 targets from hosts whose byte order differs.
6673 * New -mapped and -readnow options
6675 If memory-mapped files are available on your system through the 'mmap'
6676 system call, you can use the -mapped option on the `file' or
6677 `symbol-file' commands to cause GDB to write the symbols from your
6678 program into a reusable file. If the program you are debugging is
6679 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6680 Future GDB debugging sessions will notice the presence of this file,
6681 and will quickly map in symbol information from it, rather than reading
6682 the symbol table from the executable program. Using the '-mapped'
6683 option in a GDB `file' or `symbol-file' command has the same effect as
6684 starting GDB with the '-mapped' command-line option.
6686 You can cause GDB to read the entire symbol table immediately by using
6687 the '-readnow' option with any of the commands that load symbol table
6688 information (or on the GDB command line). This makes the command
6689 slower, but makes future operations faster.
6691 The -mapped and -readnow options are typically combined in order to
6692 build a `fred.syms' file that contains complete symbol information.
6693 A simple GDB invocation to do nothing but build a `.syms' file for future
6696 gdb -batch -nx -mapped -readnow programname
6698 The `.syms' file is specific to the host machine on which GDB is run.
6699 It holds an exact image of GDB's internal symbol table. It cannot be
6700 shared across multiple host platforms.
6702 * longjmp() handling
6704 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6705 siglongjmp() without losing control. This feature has not yet been ported to
6706 all systems. It currently works on many 386 platforms, all MIPS-based
6707 platforms (SGI, DECstation, etc), and Sun3/4.
6711 Preliminary work has been put in to support the new Solaris OS from Sun. At
6712 this time, it can control and debug processes, but it is not capable of
6717 As always, many many bug fixes. The major areas were with g++, and mipsread.
6718 People using the MIPS-based platforms should experience fewer mysterious
6719 crashes and trashed symbol tables.
6721 *** Changes in GDB-4.4:
6723 * New machines supported (host and target)
6725 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6727 BSD Reno on Vax vax-dec-bsd
6728 Ultrix on Vax vax-dec-ultrix
6730 * New machines supported (target)
6732 AMD 29000 embedded, using EBMON a29k-none-none
6736 GDB continues to improve its handling of C++. `References' work better.
6737 The demangler has also been improved, and now deals with symbols mangled as
6738 per the Annotated C++ Reference Guide.
6740 GDB also now handles `stabs' symbol information embedded in MIPS
6741 `ecoff' symbol tables. Since the ecoff format was not easily
6742 extensible to handle new languages such as C++, this appeared to be a
6743 good way to put C++ debugging info into MIPS binaries. This option
6744 will be supported in the GNU C compiler, version 2, when it is
6747 * New features for SVR4
6749 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6750 shared libraries. Debugging dynamically linked programs should present
6751 only minor differences from debugging statically linked programs.
6753 The `info proc' command will print out information about any process
6754 on an SVR4 system (including the one you are debugging). At the moment,
6755 it prints the address mappings of the process.
6757 If you bring up GDB on another SVR4 system, please send mail to
6758 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6760 * Better dynamic linking support in SunOS
6762 Reading symbols from shared libraries which contain debugging symbols
6763 now works properly. However, there remain issues such as automatic
6764 skipping of `transfer vector' code during function calls, which
6765 make it harder to debug code in a shared library, than to debug the
6766 same code linked statically.
6770 GDB is now using the latest `getopt' routines from the FSF. This
6771 version accepts the -- prefix for options with long names. GDB will
6772 continue to accept the old forms (-option and +option) as well.
6773 Various single letter abbreviations for options have been explicity
6774 added to the option table so that they won't get overshadowed in the
6775 future by other options that begin with the same letter.
6779 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6780 Many assorted bugs have been handled. Many more remain to be handled.
6781 See the various ChangeLog files (primarily in gdb and bfd) for details.
6784 *** Changes in GDB-4.3:
6786 * New machines supported (host and target)
6788 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6789 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6790 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6792 * Almost SCO Unix support
6794 We had hoped to support:
6795 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6796 (except for core file support), but we discovered very late in the release
6797 that it has problems with process groups that render gdb unusable. Sorry
6798 about that. I encourage people to fix it and post the fixes.
6800 * Preliminary ELF and DWARF support
6802 GDB can read ELF object files on System V Release 4, and can handle
6803 debugging records for C, in DWARF format, in ELF files. This support
6804 is preliminary. If you bring up GDB on another SVR4 system, please
6805 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6810 GDB now uses the latest `readline' library. One user-visible change
6811 is that two tabs will list possible command completions, which previously
6812 required typing M-? (meta-question mark, or ESC ?).
6816 The `stepi' bug that many of you noticed has been squashed.
6817 Many bugs in C++ have been handled. Many more remain to be handled.
6818 See the various ChangeLog files (primarily in gdb and bfd) for details.
6820 * State of the MIPS world (in case you wondered):
6822 GDB can understand the symbol tables emitted by the compilers
6823 supplied by most vendors of MIPS-based machines, including DEC. These
6824 symbol tables are in a format that essentially nobody else uses.
6826 Some versions of gcc come with an assembler post-processor called
6827 mips-tfile. This program is required if you want to do source-level
6828 debugging of gcc-compiled programs. I believe FSF does not ship
6829 mips-tfile with gcc version 1, but it will eventually come with gcc
6832 Debugging of g++ output remains a problem. g++ version 1.xx does not
6833 really support it at all. (If you're lucky, you should be able to get
6834 line numbers and stack traces to work, but no parameters or local
6835 variables.) With some work it should be possible to improve the
6838 When gcc version 2 is released, you will have somewhat better luck.
6839 However, even then you will get confusing results for inheritance and
6842 We will eventually provide full debugging of g++ output on
6843 DECstations. This will probably involve some kind of stabs-in-ecoff
6844 encapulation, but the details have not been worked out yet.
6847 *** Changes in GDB-4.2:
6849 * Improved configuration
6851 Only one copy of `configure' exists now, and it is not self-modifying.
6852 Porting BFD is simpler.
6856 The `step' and `next' commands now only stop at the first instruction
6857 of a source line. This prevents the multiple stops that used to occur
6858 in switch statements, for-loops, etc. `Step' continues to stop if a
6859 function that has debugging information is called within the line.
6863 Lots of small bugs fixed. More remain.
6865 * New host supported (not target)
6867 Intel 386 PC clone running Mach i386-none-mach
6870 *** Changes in GDB-4.1:
6872 * Multiple source language support
6874 GDB now has internal scaffolding to handle several source languages.
6875 It determines the type of each source file from its filename extension,
6876 and will switch expression parsing and number formatting to match the
6877 language of the function in the currently selected stack frame.
6878 You can also specifically set the language to be used, with
6879 `set language c' or `set language modula-2'.
6883 GDB now has preliminary support for the GNU Modula-2 compiler,
6884 currently under development at the State University of New York at
6885 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
6886 continue through the fall of 1991 and into 1992.
6888 Other Modula-2 compilers are currently not supported, and attempting to
6889 debug programs compiled with them will likely result in an error as the
6890 symbol table is read. Feel free to work on it, though!
6892 There are hooks in GDB for strict type checking and range checking,
6893 in the `Modula-2 philosophy', but they do not currently work.
6897 GDB can now write to executable and core files (e.g. patch
6898 a variable's value). You must turn this switch on, specify
6899 the file ("exec foo" or "core foo"), *then* modify it, e.g.
6900 by assigning a new value to a variable. Modifications take
6903 * Automatic SunOS shared library reading
6905 When you run your program, GDB automatically determines where its
6906 shared libraries (if any) have been loaded, and reads their symbols.
6907 The `share' command is no longer needed. This also works when
6908 examining core files.
6912 You can specify the number of lines that the `list' command shows.
6915 * New machines supported (host and target)
6917 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
6918 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
6919 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
6921 * New hosts supported (not targets)
6923 IBM RT/PC: romp-ibm-aix or rtpc
6925 * New targets supported (not hosts)
6927 AMD 29000 embedded with COFF a29k-none-coff
6928 AMD 29000 embedded with a.out a29k-none-aout
6929 Ultracomputer remote kernel debug a29k-nyu-kern
6931 * New remote interfaces
6937 *** Changes in GDB-4.0:
6941 Wide output is wrapped at good places to make the output more readable.
6943 Gdb now supports cross-debugging from a host machine of one type to a
6944 target machine of another type. Communication with the target system
6945 is over serial lines. The ``target'' command handles connecting to the
6946 remote system; the ``load'' command will download a program into the
6947 remote system. Serial stubs for the m68k and i386 are provided. Gdb
6948 also supports debugging of realtime processes running under VxWorks,
6949 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
6950 stub on the target system.
6952 New CPUs supported include the AMD 29000 and Intel 960.
6954 GDB now reads object files and symbol tables via a ``binary file''
6955 library, which allows a single copy of GDB to debug programs of multiple
6956 object file types such as a.out and coff.
6958 There is now a GDB reference card in "doc/refcard.tex". (Make targets
6959 refcard.dvi and refcard.ps are available to format it).
6962 * Control-Variable user interface simplified
6964 All variables that control the operation of the debugger can be set
6965 by the ``set'' command, and displayed by the ``show'' command.
6967 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
6968 ``Show prompt'' produces the response:
6969 Gdb's prompt is new-gdb=>.
6971 What follows are the NEW set commands. The command ``help set'' will
6972 print a complete list of old and new set commands. ``help set FOO''
6973 will give a longer description of the variable FOO. ``show'' will show
6974 all of the variable descriptions and their current settings.
6976 confirm on/off: Enables warning questions for operations that are
6977 hard to recover from, e.g. rerunning the program while
6978 it is already running. Default is ON.
6980 editing on/off: Enables EMACS style command line editing
6981 of input. Previous lines can be recalled with
6982 control-P, the current line can be edited with control-B,
6983 you can search for commands with control-R, etc.
6986 history filename NAME: NAME is where the gdb command history
6987 will be stored. The default is .gdb_history,
6988 or the value of the environment variable
6991 history size N: The size, in commands, of the command history. The
6992 default is 256, or the value of the environment variable
6995 history save on/off: If this value is set to ON, the history file will
6996 be saved after exiting gdb. If set to OFF, the
6997 file will not be saved. The default is OFF.
6999 history expansion on/off: If this value is set to ON, then csh-like
7000 history expansion will be performed on
7001 command line input. The default is OFF.
7003 radix N: Sets the default radix for input and output. It can be set
7004 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7005 in the current radix, so "set radix 10" is always a no-op.
7007 height N: This integer value is the number of lines on a page. Default
7008 is 24, the current `stty rows'' setting, or the ``li#''
7009 setting from the termcap entry matching the environment
7012 width N: This integer value is the number of characters on a line.
7013 Default is 80, the current `stty cols'' setting, or the ``co#''
7014 setting from the termcap entry matching the environment
7017 Note: ``set screensize'' is obsolete. Use ``set height'' and
7018 ``set width'' instead.
7020 print address on/off: Print memory addresses in various command displays,
7021 such as stack traces and structure values. Gdb looks
7022 more ``symbolic'' if you turn this off; it looks more
7023 ``machine level'' with it on. Default is ON.
7025 print array on/off: Prettyprint arrays. New convenient format! Default
7028 print demangle on/off: Print C++ symbols in "source" form if on,
7031 print asm-demangle on/off: Same, for assembler level printouts
7034 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7037 * Support for Epoch Environment.
7039 The epoch environment is a version of Emacs v18 with windowing. One
7040 new command, ``inspect'', is identical to ``print'', except that if you
7041 are running in the epoch environment, the value is printed in its own
7045 * Support for Shared Libraries
7047 GDB can now debug programs and core files that use SunOS shared libraries.
7048 Symbols from a shared library cannot be referenced
7049 before the shared library has been linked with the program (this
7050 happens after you type ``run'' and before the function main() is entered).
7051 At any time after this linking (including when examining core files
7052 from dynamically linked programs), gdb reads the symbols from each
7053 shared library when you type the ``sharedlibrary'' command.
7054 It can be abbreviated ``share''.
7056 sharedlibrary REGEXP: Load shared object library symbols for files
7057 matching a unix regular expression. No argument
7058 indicates to load symbols for all shared libraries.
7060 info sharedlibrary: Status of loaded shared libraries.
7065 A watchpoint stops execution of a program whenever the value of an
7066 expression changes. Checking for this slows down execution
7067 tremendously whenever you are in the scope of the expression, but is
7068 quite useful for catching tough ``bit-spreader'' or pointer misuse
7069 problems. Some machines such as the 386 have hardware for doing this
7070 more quickly, and future versions of gdb will use this hardware.
7072 watch EXP: Set a watchpoint (breakpoint) for an expression.
7074 info watchpoints: Information about your watchpoints.
7076 delete N: Deletes watchpoint number N (same as breakpoints).
7077 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7078 enable N: Re-enables watchpoint number N (same as breakpoints).
7081 * C++ multiple inheritance
7083 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7086 * C++ exception handling
7088 Gdb now supports limited C++ exception handling. Besides the existing
7089 ability to breakpoint on an exception handler, gdb can breakpoint on
7090 the raising of an exception (before the stack is peeled back to the
7093 catch FOO: If there is a FOO exception handler in the dynamic scope,
7094 set a breakpoint to catch exceptions which may be raised there.
7095 Multiple exceptions (``catch foo bar baz'') may be caught.
7097 info catch: Lists all exceptions which may be caught in the
7098 current stack frame.
7101 * Minor command changes
7103 The command ``call func (arg, arg, ...)'' now acts like the print
7104 command, except it does not print or save a value if the function's result
7105 is void. This is similar to dbx usage.
7107 The ``up'' and ``down'' commands now always print the frame they end up
7108 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7109 frames without printing.
7111 * New directory command
7113 'dir' now adds directories to the FRONT of the source search path.
7114 The path starts off empty. Source files that contain debug information
7115 about the directory in which they were compiled can be found even
7116 with an empty path; Sun CC and GCC include this information. If GDB can't
7117 find your source file in the current directory, type "dir .".
7119 * Configuring GDB for compilation
7121 For normal use, type ``./configure host''. See README or gdb.texinfo
7124 GDB now handles cross debugging. If you are remotely debugging between
7125 two different machines, type ``./configure host -target=targ''.
7126 Host is the machine where GDB will run; targ is the machine
7127 where the program that you are debugging will run.