1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 8.2
6 * GDB and GDBserver now support access to additional registers on
7 PowerPC GNU/Linux targets: PPR, DSCR, TAR, EBB/PMU registers, and
10 * GDB now has experimental support for the compilation and injection of
11 C++ source code into the inferior. This beta release does not include
12 support for several language features, such as templates, constructors,
15 This feature requires GCC 7.1 or higher built with libcp1.so
18 * GDB and GDBserver now support IPv6 connections. IPv6 addresses
19 can be passed using the '[ADDRESS]:PORT' notation, or the regular
20 'ADDRESS:PORT' method.
22 * DWARF index cache: GDB can now automatically save indices of DWARF
23 symbols on disk to speed up further loading of the same binaries.
25 * Ada task switching is now supported on aarch64-elf targets when
26 debugging a program using the Ravenscar Profile. For more information,
27 see the "Tasking Support when using the Ravenscar Profile" section
28 in the GDB user manual.
30 * GDB in batch mode now exits with status 1 if the last command to be
33 * Changes to the "frame", "select-frame", and "info frame" CLI
34 commands. These commands all now take a frame specification which
35 is either a frame level, or one of the keywords 'level', 'address',
36 'function', or 'view' followed by a parameter. Selecting a frame by
37 address, or viewing a frame outside the current backtrace now
38 requires the use of a keyword. Selecting a frame by level is
39 unchanged. The MI comment "-stack-select-frame" is unchanged.
41 * The RISC-V target now supports target descriptions.
43 * System call catchpoints now support system call aliases on FreeBSD.
44 When the ABI of a system call changes in FreeBSD, this is
45 implemented by leaving a compatibility system call using the old ABI
46 at the existing number and allocating a new system call number for
47 the new ABI. For example, FreeBSD 12 altered the layout of 'struct
48 kevent' used by the 'kevent' system call. As a result, FreeBSD 12
49 kernels ship with both 'kevent' and 'freebsd11_kevent' system calls.
50 The 'freebsd11_kevent' system call is assigned an alias of 'kevent'
51 so that a system call catchpoint for the 'kevent' system call will
52 catch invocations of both the 'kevent' and 'freebsd11_kevent'
53 binaries. This ensures that 'kevent' system calls are caught for
54 binaries using either the old or new ABIs.
59 GNU/Linux/OpenRISC or1k*-*-linux*
63 set debug compile-cplus-types
64 show debug compile-cplus-types
65 Control the display of debug output about type conversion in the
66 C++ compile feature. Commands have no effect while compiliong
71 Control whether debug output about files/functions skipping is
74 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
75 Apply a command to some frames.
76 FLAG arguments allow to control what output to produce and how to handle
77 errors raised when applying COMMAND to a frame.
80 Apply a command to all threads (ignoring errors and empty output).
81 Shortcut for 'thread apply all -s COMMAND'.
84 Apply a command to all frames (ignoring errors and empty output).
85 Shortcut for 'frame apply all -s COMMAND'.
88 Apply a command to all frames of all threads (ignoring errors and empty
90 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
92 maint set dwarf unwinders (on|off)
93 maint show dwarf unwinders
94 Control whether DWARF unwinders can be used.
97 Display a list of open files for a process.
101 target remote FILENAME
102 target extended-remote FILENAME
103 If FILENAME is a Unix domain socket, GDB will attempt to connect
104 to this socket instead of opening FILENAME as a character device.
106 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
107 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
108 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
109 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
110 These commands can now print only the searched entities
111 matching the provided regexp(s), giving a condition
112 on the entity names or entity types. The flag -q disables
113 printing headers or informations messages.
119 These commands now determine the syntax for the shown entities
120 according to the language chosen by `set language'. In particular,
121 `set language auto' means to automatically choose the language of
124 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
125 The 'thread apply' command accepts new FLAG arguments.
126 FLAG arguments allow to control what output to produce and how to handle
127 errors raised when applying COMMAND to a thread.
129 set tui tab-width NCHARS
130 show tui tab-width NCHARS
131 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
135 ** The '-data-disassemble' MI command now accepts an '-a' option to
136 disassemble the whole function surrounding the given program
137 counter value or function name. Support for this feature can be
138 verified by using the "-list-features" command, which should
139 contain "data-disassemble-a-option".
141 ** Command responses and notifications that include a frame now include
142 the frame's architecture in a new "arch" attribute.
144 * New native configurations
146 GNU/Linux/RISC-V riscv*-*-linux*
147 FreeBSD/riscv riscv*-*-freebsd*
151 GNU/Linux/RISC-V riscv*-*-linux*
153 CSKY GNU/LINUX csky*-*-linux
154 FreeBSD/riscv riscv*-*-freebsd*
158 ** The gdb.Inferior type has a new 'progspace' property, which is the program
159 space associated to that inferior.
161 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
162 of objfiles associated to that program space.
164 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
165 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
168 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
169 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
170 correct and did not work properly.
176 Enable or disable the undefined behavior sanitizer. This is
177 disabled by default, but passing --enable-ubsan=yes or
178 --enable-ubsan=auto to configure will enable it. Enabling this can
179 cause a performance penalty. The undefined behavior sanitizer was
180 first introduced in GCC 4.9.
182 *** Changes in GDB 8.2
184 * The 'set disassembler-options' command now supports specifying options
187 * The 'symbol-file' command now accepts an '-o' option to add a relative
188 offset to all sections.
190 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
191 a relative offset to all sections, but it allows to override the load
192 address of individual sections using '-s'.
194 * The 'add-symbol-file' command no longer requires the second argument
195 (address of the text section).
197 * The endianness used with the 'set endian auto' mode in the absence of
198 an executable selected for debugging is now the last endianness chosen
199 either by one of the 'set endian big' and 'set endian little' commands
200 or by inferring from the last executable used, rather than the startup
203 * The pager now allows a "c" response, meaning to disable the pager
204 for the rest of the current command.
206 * The commands 'info variables/functions/types' now show the source line
207 numbers of symbol definitions when available.
209 * 'info proc' now works on running processes on FreeBSD systems and core
210 files created on FreeBSD systems.
212 * C expressions can now use _Alignof, and C++ expressions can now use
215 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
216 the vector length while the process is running.
222 Control display of debugging info regarding the FreeBSD native target.
224 set|show varsize-limit
225 This new setting allows the user to control the maximum size of Ada
226 objects being printed when those objects have a variable type,
227 instead of that maximum size being hardcoded to 65536 bytes.
229 set|show record btrace cpu
230 Controls the processor to be used for enabling errata workarounds for
233 maint check libthread-db
234 Run integrity checks on the current inferior's thread debugging
237 maint set check-libthread-db (on|off)
238 maint show check-libthread-db
239 Control whether to run integrity checks on inferior specific thread
240 debugging libraries as they are loaded. The default is not to
245 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
247 ** The commands attached to a breakpoint can be set by assigning to
248 the breakpoint's "commands" field.
250 ** gdb.execute can now execute multi-line gdb commands.
252 ** The new functions gdb.convenience_variable and
253 gdb.set_convenience_variable can be used to get and set the value
254 of convenience variables.
256 ** A gdb.Parameter will no longer print the "set" help text on an
257 ordinary "set"; instead by default a "set" will be silent unless
258 the get_set_string method returns a non-empty string.
262 RiscV ELF riscv*-*-elf
264 * Removed targets and native configurations
266 m88k running OpenBSD m88*-*-openbsd*
267 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
268 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
269 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
271 * Aarch64/Linux hardware watchpoints improvements
273 Hardware watchpoints on unaligned addresses are now properly
274 supported when running Linux kernel 4.10 or higher: read and access
275 watchpoints are no longer spuriously missed, and all watchpoints
276 lengths between 1 and 8 bytes are supported. On older kernels,
277 watchpoints set on unaligned addresses are no longer missed, with
278 the tradeoff that there is a possibility of false hits being
283 --enable-codesign=CERT
284 This can be used to invoke "codesign -s CERT" after building gdb.
285 This option is useful on macOS, where code signing is required for
286 gdb to work properly.
288 --disable-gdbcli has been removed
289 This is now silently accepted, but does nothing.
291 *** Changes in GDB 8.1
293 * GDB now supports dynamically creating arbitrary register groups specified
294 in XML target descriptions. This allows for finer grain grouping of
295 registers on systems with a large amount of registers.
297 * The 'ptype' command now accepts a '/o' flag, which prints the
298 offsets and sizes of fields in a struct, like the pahole(1) tool.
300 * New "--readnever" command line option instructs GDB to not read each
301 symbol file's symbolic debug information. This makes startup faster
302 but at the expense of not being able to perform symbolic debugging.
303 This option is intended for use cases where symbolic debugging will
304 not be used, e.g., when you only need to dump the debuggee's core.
306 * GDB now uses the GNU MPFR library, if available, to emulate target
307 floating-point arithmetic during expression evaluation when the target
308 uses different floating-point formats than the host. At least version
309 3.1 of GNU MPFR is required.
311 * GDB now supports access to the guarded-storage-control registers and the
312 software-based guarded-storage broadcast control registers on IBM z14.
314 * On Unix systems, GDB now supports transmitting environment variables
315 that are to be set or unset to GDBserver. These variables will
316 affect the environment to be passed to the remote inferior.
318 To inform GDB of environment variables that are to be transmitted to
319 GDBserver, use the "set environment" command. Only user set
320 environment variables are sent to GDBserver.
322 To inform GDB of environment variables that are to be unset before
323 the remote inferior is started by the GDBserver, use the "unset
324 environment" command.
326 * Completion improvements
328 ** GDB can now complete function parameters in linespecs and
329 explicit locations without quoting. When setting breakpoints,
330 quoting around functions names to help with TAB-completion is
331 generally no longer necessary. For example, this now completes
334 (gdb) b function(in[TAB]
335 (gdb) b function(int)
337 Related, GDB is no longer confused with completing functions in
338 C++ anonymous namespaces:
341 (gdb) b (anonymous namespace)::[TAB][TAB]
342 (anonymous namespace)::a_function()
343 (anonymous namespace)::b_function()
345 ** GDB now has much improved linespec and explicit locations TAB
346 completion support, that better understands what you're
347 completing and offers better suggestions. For example, GDB no
348 longer offers data symbols as possible completions when you're
349 setting a breakpoint.
351 ** GDB now TAB-completes label symbol names.
353 ** The "complete" command now mimics TAB completion accurately.
355 * New command line options (gcore)
358 Dump all memory mappings.
360 * Breakpoints on C++ functions are now set on all scopes by default
362 By default, breakpoints on functions/methods are now interpreted as
363 specifying all functions with the given name ignoring missing
364 leading scopes (namespaces and classes).
366 For example, assuming a C++ program with symbols named:
371 both commands "break func()" and "break B::func()" set a breakpoint
374 You can use the new flag "-qualified" to override this. This makes
375 GDB interpret the specified function name as a complete
376 fully-qualified name instead. For example, using the same C++
377 program, the "break -q B::func" command sets a breakpoint on
378 "B::func", only. A parameter has been added to the Python
379 gdb.Breakpoint constructor to achieve the same result when creating
380 a breakpoint from Python.
382 * Breakpoints on functions marked with C++ ABI tags
384 GDB can now set breakpoints on functions marked with C++ ABI tags
385 (e.g., [abi:cxx11]). See here for a description of ABI tags:
386 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
388 Functions with a C++11 abi tag are demangled/displayed like this:
390 function[abi:cxx11](int)
393 You can now set a breakpoint on such functions simply as if they had
396 (gdb) b function(int)
398 Or if you need to disambiguate between tags, like:
400 (gdb) b function[abi:other_tag](int)
402 Tab completion was adjusted accordingly as well.
406 ** New events gdb.new_inferior, gdb.inferior_deleted, and
407 gdb.new_thread are emitted. See the manual for further
408 description of these.
410 ** A new function, "gdb.rbreak" has been added to the Python API.
411 This function allows the setting of a large number of breakpoints
412 via a regex pattern in Python. See the manual for further details.
414 ** Python breakpoints can now accept explicit locations. See the
415 manual for a further description of this feature.
418 * New features in the GDB remote stub, GDBserver
420 ** GDBserver is now able to start inferior processes with a
421 specified initial working directory.
423 The user can set the desired working directory to be used from
424 GDB using the new "set cwd" command.
426 ** New "--selftest" command line option runs some GDBserver self
427 tests. These self tests are disabled in releases.
429 ** On Unix systems, GDBserver now does globbing expansion and variable
430 substitution in inferior command line arguments.
432 This is done by starting inferiors using a shell, like GDB does.
433 See "set startup-with-shell" in the user manual for how to disable
434 this from GDB when using "target extended-remote". When using
435 "target remote", you can disable the startup with shell by using the
436 new "--no-startup-with-shell" GDBserver command line option.
438 ** On Unix systems, GDBserver now supports receiving environment
439 variables that are to be set or unset from GDB. These variables
440 will affect the environment to be passed to the inferior.
442 * When catching an Ada exception raised with a message, GDB now prints
443 the message in the catchpoint hit notification. In GDB/MI mode, that
444 information is provided as an extra field named "exception-message"
445 in the *stopped notification.
447 * Trait objects can now be inspected When debugging Rust code. This
448 requires compiler support which will appear in Rust 1.24.
452 QEnvironmentHexEncoded
453 Inform GDBserver of an environment variable that is to be passed to
454 the inferior when starting it.
457 Inform GDBserver of an environment variable that is to be unset
458 before starting the remote inferior.
461 Inform GDBserver that the environment should be reset (i.e.,
462 user-set environment variables should be unset).
465 Indicates whether the inferior must be started with a shell or not.
468 Tell GDBserver that the inferior to be started should use a specific
471 * The "maintenance print c-tdesc" command now takes an optional
472 argument which is the file name of XML target description.
474 * The "maintenance selftest" command now takes an optional argument to
475 filter the tests to be run.
477 * The "enable", and "disable" commands now accept a range of
478 breakpoint locations, e.g. "enable 1.3-5".
483 Set and show the current working directory for the inferior.
486 Set and show compilation command used for compiling and injecting code
487 with the 'compile' commands.
489 set debug separate-debug-file
490 show debug separate-debug-file
491 Control the display of debug output about separate debug file search.
493 set dump-excluded-mappings
494 show dump-excluded-mappings
495 Control whether mappings marked with the VM_DONTDUMP flag should be
496 dumped when generating a core file.
499 List the registered selftests.
502 Start the debugged program stopping at the first instruction.
505 Control display of debugging messages related to OpenRISC targets.
507 set|show print type nested-type-limit
508 Set and show the limit of nesting level for nested types that the
509 type printer will show.
511 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
514 * Safer/improved support for debugging with no debug info
516 GDB no longer assumes functions with no debug information return
519 This means that GDB now refuses to call such functions unless you
520 tell it the function's type, by either casting the call to the
521 declared return type, or by casting the function to a function
522 pointer of the right type, and calling that:
524 (gdb) p getenv ("PATH")
525 'getenv' has unknown return type; cast the call to its declared return type
526 (gdb) p (char *) getenv ("PATH")
527 $1 = 0x7fffffffe "/usr/local/bin:/"...
528 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
529 $2 = 0x7fffffffe "/usr/local/bin:/"...
531 Similarly, GDB no longer assumes that global variables with no debug
532 info have type 'int', and refuses to print the variable's value
533 unless you tell it the variable's type:
536 'var' has unknown type; cast it to its declared type
540 * New native configurations
542 FreeBSD/aarch64 aarch64*-*-freebsd*
543 FreeBSD/arm arm*-*-freebsd*
547 FreeBSD/aarch64 aarch64*-*-freebsd*
548 FreeBSD/arm arm*-*-freebsd*
549 OpenRISC ELF or1k*-*-elf
551 * Removed targets and native configurations
553 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
555 *** Changes in GDB 8.0
557 * GDB now supports access to the PKU register on GNU/Linux. The register is
558 added by the Memory Protection Keys for Userspace feature which will be
559 available in future Intel CPUs.
561 * GDB now supports C++11 rvalue references.
565 ** New functions to start, stop and access a running btrace recording.
566 ** Rvalue references are now supported in gdb.Type.
568 * GDB now supports recording and replaying rdrand and rdseed Intel 64
571 * Building GDB and GDBserver now requires a C++11 compiler.
573 For example, GCC 4.8 or later.
575 It is no longer possible to build GDB or GDBserver with a C
576 compiler. The --disable-build-with-cxx configure option has been
579 * Building GDB and GDBserver now requires GNU make >= 3.81.
581 It is no longer supported to build GDB or GDBserver with another
582 implementation of the make program or an earlier version of GNU make.
584 * Native debugging on MS-Windows supports command-line redirection
586 Command-line arguments used for starting programs on MS-Windows can
587 now include redirection symbols supported by native Windows shells,
588 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
589 as "run", "start", and "set args", as well as the corresponding MI
592 * Support for thread names on MS-Windows.
594 GDB now catches and handles the special exception that programs
595 running on MS-Windows use to assign names to threads in the
598 * Support for Java programs compiled with gcj has been removed.
600 * User commands now accept an unlimited number of arguments.
601 Previously, only up to 10 was accepted.
603 * The "eval" command now expands user-defined command arguments.
605 This makes it easier to process a variable number of arguments:
610 eval "print $arg%d", $i
615 * Target descriptions can now describe registers for sparc32 and sparc64.
617 * GDB now supports DWARF version 5 (debug information format).
618 Its .debug_names index is not yet supported.
620 * New native configurations
622 FreeBSD/mips mips*-*-freebsd
626 Synopsys ARC arc*-*-elf32
627 FreeBSD/mips mips*-*-freebsd
629 * Removed targets and native configurations
631 Alpha running FreeBSD alpha*-*-freebsd*
632 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
637 Erases all the flash memory regions reported by the target.
639 maint print arc arc-instruction address
640 Print internal disassembler information about instruction at a given address.
644 set disassembler-options
645 show disassembler-options
646 Controls the passing of target specific information to the disassembler.
647 If it is necessary to specify more than one disassembler option then
648 multiple options can be placed together into a comma separated list.
649 The default value is the empty string. Currently, the only supported
650 targets are ARM, PowerPC and S/390.
655 Erases all the flash memory regions reported by the target. This is
656 equivalent to the CLI command flash-erase.
658 -file-list-shared-libraries
659 List the shared libraries in the program. This is
660 equivalent to the CLI command "info shared".
663 Catchpoints stopping the program when Ada exceptions are
664 handled. This is equivalent to the CLI command "catch handlers".
666 *** Changes in GDB 7.12
668 * GDB and GDBserver now build with a C++ compiler by default.
670 The --enable-build-with-cxx configure option is now enabled by
671 default. One must now explicitly configure with
672 --disable-build-with-cxx in order to build with a C compiler. This
673 option will be removed in a future release.
675 * GDBserver now supports recording btrace without maintaining an active
678 * GDB now supports a negative repeat count in the 'x' command to examine
679 memory backward from the given address. For example:
682 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
683 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
684 (gdb) x/-5i 0x0000000000400580
685 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
686 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
687 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
688 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
689 0x40057b <main(int, char**)+25>:
690 callq 0x400536 <Func1(int, char const*)>
692 * Fortran: Support structures with fields of dynamic types and
693 arrays of dynamic types.
695 * The symbol dumping maintenance commands have new syntax.
696 maint print symbols [-pc address] [--] [filename]
697 maint print symbols [-objfile objfile] [-source source] [--] [filename]
698 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
699 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
700 maint print msymbols [-objfile objfile] [--] [filename]
702 * GDB now supports multibit bitfields and enums in target register
705 * New Python-based convenience function $_as_string(val), which returns
706 the textual representation of a value. This function is especially
707 useful to obtain the text label of an enum value.
709 * Intel MPX bound violation handling.
711 Segmentation faults caused by a Intel MPX boundary violation
712 now display the kind of violation (upper or lower), the memory
713 address accessed and the memory bounds, along with the usual
714 signal received and code location.
718 Program received signal SIGSEGV, Segmentation fault
719 Upper bound violation while accessing address 0x7fffffffc3b3
720 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
721 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
723 * Rust language support.
724 GDB now supports debugging programs written in the Rust programming
725 language. See https://www.rust-lang.org/ for more information about
728 * Support for running interpreters on specified input/output devices
730 GDB now supports a new mechanism that allows frontends to provide
731 fully featured GDB console views, as a better alternative to
732 building such views on top of the "-interpreter-exec console"
733 command. See the new "new-ui" command below. With that command,
734 frontends can now start GDB in the traditional command-line mode
735 running in an embedded terminal emulator widget, and create a
736 separate MI interpreter running on a specified i/o device. In this
737 way, GDB handles line editing, history, tab completion, etc. in the
738 console all by itself, and the GUI uses the separate MI interpreter
739 for its own control and synchronization, invisible to the command
742 * The "catch syscall" command catches groups of related syscalls.
744 The "catch syscall" command now supports catching a group of related
745 syscalls using the 'group:' or 'g:' prefix.
750 skip -gfile file-glob-pattern
751 skip -function function
752 skip -rfunction regular-expression
753 A generalized form of the skip command, with new support for
754 glob-style file names and regular expressions for function names.
755 Additionally, a file spec and a function spec may now be combined.
757 maint info line-table REGEXP
758 Display the contents of GDB's internal line table data struture.
761 Run any GDB unit tests that were compiled in.
764 Start a new user interface instance running INTERP as interpreter,
765 using the TTY file for input/output.
769 ** gdb.Breakpoint objects have a new attribute "pending", which
770 indicates whether the breakpoint is pending.
771 ** Three new breakpoint-related events have been added:
772 gdb.breakpoint_created, gdb.breakpoint_modified, and
773 gdb.breakpoint_deleted.
776 Signal ("set") the given MS-Windows event object. This is used in
777 conjunction with the Windows JIT debugging (AeDebug) support, where
778 the OS suspends a crashing process until a debugger can attach to
779 it. Resuming the crashing process, in order to debug it, is done by
782 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
783 was added in GDBserver, including JIT compiling fast tracepoint's
784 conditional expression bytecode into native code.
786 * Support for various remote target protocols and ROM monitors has
789 target m32rsdi Remote M32R debugging over SDI
790 target mips MIPS remote debugging protocol
791 target pmon PMON ROM monitor
792 target ddb NEC's DDB variant of PMON for Vr4300
793 target rockhopper NEC RockHopper variant of PMON
794 target lsi LSI variant of PMO
796 * Support for tracepoints and fast tracepoints on powerpc-linux,
797 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
798 including JIT compiling fast tracepoint's conditional expression
799 bytecode into native code.
801 * MI async record =record-started now includes the method and format used for
802 recording. For example:
804 =record-started,thread-group="i1",method="btrace",format="bts"
806 * MI async record =thread-selected now includes the frame field. For example:
808 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
812 Andes NDS32 nds32*-*-elf
814 *** Changes in GDB 7.11
816 * GDB now supports debugging kernel-based threads on FreeBSD.
818 * Per-inferior thread numbers
820 Thread numbers are now per inferior instead of global. If you're
821 debugging multiple inferiors, GDB displays thread IDs using a
822 qualified INF_NUM.THR_NUM form. For example:
826 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
827 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
828 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
829 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
831 As consequence, thread numbers as visible in the $_thread
832 convenience variable and in Python's InferiorThread.num attribute
833 are no longer unique between inferiors.
835 GDB now maintains a second thread ID per thread, referred to as the
836 global thread ID, which is the new equivalent of thread numbers in
837 previous releases. See also $_gthread below.
839 For backwards compatibility, MI's thread IDs always refer to global
842 * Commands that accept thread IDs now accept the qualified
843 INF_NUM.THR_NUM form as well. For example:
846 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
849 * In commands that accept a list of thread IDs, you can now refer to
850 all threads of an inferior using a star wildcard. GDB accepts
851 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
852 refer to all threads of the current inferior. For example, "info
855 * You can use "info threads -gid" to display the global thread ID of
858 * The new convenience variable $_gthread holds the global number of
861 * The new convenience variable $_inferior holds the number of the
864 * GDB now displays the ID and name of the thread that hit a breakpoint
865 or received a signal, if your program is multi-threaded. For
868 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
869 Thread 1 "main" received signal SIGINT, Interrupt.
871 * Record btrace now supports non-stop mode.
873 * Support for tracepoints on aarch64-linux was added in GDBserver.
875 * The 'record instruction-history' command now indicates speculative execution
876 when using the Intel Processor Trace recording format.
878 * GDB now allows users to specify explicit locations, bypassing
879 the linespec parser. This feature is also available to GDB/MI
882 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
883 GDB now is able to debug both AArch64 applications and ARM applications
886 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
887 including JIT compiling fast tracepoint's conditional expression bytecode
890 * GDB now supports displaced stepping on AArch64 GNU/Linux.
892 * "info threads", "info inferiors", "info display", "info checkpoints"
893 and "maint info program-spaces" now list the corresponding items in
894 ascending ID order, for consistency with all other "info" commands.
896 * In Ada, the overloads selection menu has been enhanced to display the
897 parameter types and the return types for the matching overloaded subprograms.
901 maint set target-non-stop (on|off|auto)
902 maint show target-non-stop
903 Control whether GDB targets always operate in non-stop mode even if
904 "set non-stop" is "off". The default is "auto", meaning non-stop
905 mode is enabled if supported by the target.
907 maint set bfd-sharing
908 maint show bfd-sharing
909 Control the reuse of bfd objects.
913 Control display of debugging info regarding bfd caching.
917 Control display of debugging info regarding FreeBSD threads.
919 set remote multiprocess-extensions-packet
920 show remote multiprocess-extensions-packet
921 Set/show the use of the remote protocol multiprocess extensions.
923 set remote thread-events
924 show remote thread-events
925 Set/show the use of thread create/exit events.
927 set ada print-signatures on|off
928 show ada print-signatures"
929 Control whether parameter types and return types are displayed in overloads
930 selection menus. It is activaled (@code{on}) by default.
934 Controls the maximum size of memory, in bytes, that GDB will
935 allocate for value contents. Prevents incorrect programs from
936 causing GDB to allocate overly large buffers. Default is 64k.
938 * The "disassemble" command accepts a new modifier: /s.
939 It prints mixed source+disassembly like /m with two differences:
940 - disassembled instructions are now printed in program order, and
941 - and source for all relevant files is now printed.
942 The "/m" option is now considered deprecated: its "source-centric"
943 output hasn't proved useful in practice.
945 * The "record instruction-history" command accepts a new modifier: /s.
946 It behaves exactly like /m and prints mixed source+disassembly.
948 * The "set scheduler-locking" command supports a new mode "replay".
949 It behaves like "off" in record mode and like "on" in replay mode.
951 * Support for various ROM monitors has been removed:
953 target dbug dBUG ROM monitor for Motorola ColdFire
954 target picobug Motorola picobug monitor
955 target dink32 DINK32 ROM monitor for PowerPC
956 target m32r Renesas M32R/D ROM monitor
957 target mon2000 mon2000 ROM monitor
958 target ppcbug PPCBUG ROM monitor for PowerPC
960 * Support for reading/writing memory and extracting values on architectures
961 whose memory is addressable in units of any integral multiple of 8 bits.
964 Allows to break when an Ada exception is handled.
969 Indicates that an exec system call was executed.
971 exec-events feature in qSupported
972 The qSupported packet allows GDB to request support for exec
973 events using the new 'gdbfeature' exec-event, and the qSupported
974 response can contain the corresponding 'stubfeature'. Set and
975 show commands can be used to display whether these features are enabled.
978 Equivalent to interrupting with the ^C character, but works in
981 thread created stop reason (T05 create:...)
982 Indicates that the thread was just created and is stopped at entry.
984 thread exit stop reply (w exitcode;tid)
985 Indicates that the thread has terminated.
988 Enables/disables thread create and exit event reporting. For
989 example, this is used in non-stop mode when GDB stops a set of
990 threads and synchronously waits for the their corresponding stop
991 replies. Without exit events, if one of the threads exits, GDB
992 would hang forever not knowing that it should no longer expect a
993 stop for that same thread.
996 Indicates that there are no resumed threads left in the target (all
997 threads are stopped). The remote stub reports support for this stop
998 reply to GDB's qSupported query.
1001 Enables/disables catching syscalls from the inferior process.
1002 The remote stub reports support for this packet to GDB's qSupported query.
1004 syscall_entry stop reason
1005 Indicates that a syscall was just called.
1007 syscall_return stop reason
1008 Indicates that a syscall just returned.
1010 * Extended-remote exec events
1012 ** GDB now has support for exec events on extended-remote Linux targets.
1013 For such targets with Linux kernels 2.5.46 and later, this enables
1014 follow-exec-mode and exec catchpoints.
1016 set remote exec-event-feature-packet
1017 show remote exec-event-feature-packet
1018 Set/show the use of the remote exec event feature.
1020 * Thread names in remote protocol
1022 The reply to qXfer:threads:read may now include a name attribute for each
1025 * Target remote mode fork and exec events
1027 ** GDB now has support for fork and exec events on target remote mode
1028 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1029 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1030 fork and exec catchpoints.
1032 * Remote syscall events
1034 ** GDB now has support for catch syscall on remote Linux targets,
1035 currently enabled on x86/x86_64 architectures.
1037 set remote catch-syscall-packet
1038 show remote catch-syscall-packet
1039 Set/show the use of the remote catch syscall feature.
1043 ** The -var-set-format command now accepts the zero-hexadecimal
1044 format. It outputs data in hexadecimal format with zero-padding on the
1049 ** gdb.InferiorThread objects have a new attribute "global_num",
1050 which refers to the thread's global thread ID. The existing
1051 "num" attribute now refers to the thread's per-inferior number.
1052 See "Per-inferior thread numbers" above.
1053 ** gdb.InferiorThread objects have a new attribute "inferior", which
1054 is the Inferior object the thread belongs to.
1056 *** Changes in GDB 7.10
1058 * Support for process record-replay and reverse debugging on aarch64*-linux*
1059 targets has been added. GDB now supports recording of A64 instruction set
1060 including advance SIMD instructions.
1062 * Support for Sun's version of the "stabs" debug file format has been removed.
1064 * GDB now honors the content of the file /proc/PID/coredump_filter
1065 (PID is the process ID) on GNU/Linux systems. This file can be used
1066 to specify the types of memory mappings that will be included in a
1067 corefile. For more information, please refer to the manual page of
1068 "core(5)". GDB also has a new command: "set use-coredump-filter
1069 on|off". It allows to set whether GDB will read the content of the
1070 /proc/PID/coredump_filter file when generating a corefile.
1072 * The "info os" command on GNU/Linux can now display information on
1074 "info os cpus" Listing of all cpus/cores on the system
1076 * GDB has two new commands: "set serial parity odd|even|none" and
1077 "show serial parity". These allows to set or show parity for the
1080 * The "info source" command now displays the producer string if it was
1081 present in the debug info. This typically includes the compiler version
1082 and may include things like its command line arguments.
1084 * The "info dll", an alias of the "info sharedlibrary" command,
1085 is now available on all platforms.
1087 * Directory names supplied to the "set sysroot" commands may be
1088 prefixed with "target:" to tell GDB to access shared libraries from
1089 the target system, be it local or remote. This replaces the prefix
1090 "remote:". The default sysroot has been changed from "" to
1091 "target:". "remote:" is automatically converted to "target:" for
1092 backward compatibility.
1094 * The system root specified by "set sysroot" will be prepended to the
1095 filename of the main executable (if reported to GDB as absolute by
1096 the operating system) when starting processes remotely, and when
1097 attaching to already-running local or remote processes.
1099 * GDB now supports automatic location and retrieval of executable
1100 files from remote targets. Remote debugging can now be initiated
1101 using only a "target remote" or "target extended-remote" command
1102 (no "set sysroot" or "file" commands are required). See "New remote
1105 * The "dump" command now supports verilog hex format.
1107 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1109 * On GNU/Linux, GDB and gdbserver are now able to access executable
1110 and shared library files without a "set sysroot" command when
1111 attaching to processes running in different mount namespaces from
1112 the debugger. This makes it possible to attach to processes in
1113 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1114 See "New remote packets" below.
1116 * The "tui reg" command now provides completion for all of the
1117 available register groups, including target specific groups.
1119 * The HISTSIZE environment variable is no longer read when determining
1120 the size of GDB's command history. GDB now instead reads the dedicated
1121 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1122 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1127 ** Memory ports can now be unbuffered.
1131 ** gdb.Objfile objects have a new attribute "username",
1132 which is the name of the objfile as specified by the user,
1133 without, for example, resolving symlinks.
1134 ** You can now write frame unwinders in Python.
1135 ** gdb.Type objects have a new method "optimized_out",
1136 returning optimized out gdb.Value instance of this type.
1137 ** gdb.Value objects have new methods "reference_value" and
1138 "const_value" which return a reference to the value and a
1139 "const" version of the value respectively.
1143 maint print symbol-cache
1144 Print the contents of the symbol cache.
1146 maint print symbol-cache-statistics
1147 Print statistics of symbol cache usage.
1149 maint flush-symbol-cache
1150 Flush the contents of the symbol cache.
1154 Start branch trace recording using Branch Trace Store (BTS) format.
1157 Evaluate expression by using the compiler and print result.
1161 Explicit commands for enabling and disabling tui mode.
1164 set mpx bound on i386 and amd64
1165 Support for bound table investigation on Intel MPX enabled applications.
1169 Start branch trace recording using Intel Processor Trace format.
1172 Print information about branch tracing internals.
1174 maint btrace packet-history
1175 Print the raw branch tracing data.
1177 maint btrace clear-packet-history
1178 Discard the stored raw branch tracing data.
1181 Discard all branch tracing data. It will be fetched and processed
1182 anew by the next "record" command.
1187 Renamed from "set debug dwarf2-die".
1188 show debug dwarf-die
1189 Renamed from "show debug dwarf2-die".
1191 set debug dwarf-read
1192 Renamed from "set debug dwarf2-read".
1193 show debug dwarf-read
1194 Renamed from "show debug dwarf2-read".
1196 maint set dwarf always-disassemble
1197 Renamed from "maint set dwarf2 always-disassemble".
1198 maint show dwarf always-disassemble
1199 Renamed from "maint show dwarf2 always-disassemble".
1201 maint set dwarf max-cache-age
1202 Renamed from "maint set dwarf2 max-cache-age".
1203 maint show dwarf max-cache-age
1204 Renamed from "maint show dwarf2 max-cache-age".
1206 set debug dwarf-line
1207 show debug dwarf-line
1208 Control display of debugging info regarding DWARF line processing.
1211 show max-completions
1212 Set the maximum number of candidates to be considered during
1213 completion. The default value is 200. This limit allows GDB
1214 to avoid generating large completion lists, the computation of
1215 which can cause the debugger to become temporarily unresponsive.
1217 set history remove-duplicates
1218 show history remove-duplicates
1219 Control the removal of duplicate history entries.
1221 maint set symbol-cache-size
1222 maint show symbol-cache-size
1223 Control the size of the symbol cache.
1225 set|show record btrace bts buffer-size
1226 Set and show the size of the ring buffer used for branch tracing in
1228 The obtained size may differ from the requested size. Use "info
1229 record" to see the obtained buffer size.
1231 set debug linux-namespaces
1232 show debug linux-namespaces
1233 Control display of debugging info regarding Linux namespaces.
1235 set|show record btrace pt buffer-size
1236 Set and show the size of the ring buffer used for branch tracing in
1237 Intel Processor Trace format.
1238 The obtained size may differ from the requested size. Use "info
1239 record" to see the obtained buffer size.
1241 maint set|show btrace pt skip-pad
1242 Set and show whether PAD packets are skipped when computing the
1245 * The command 'thread apply all' can now support new option '-ascending'
1246 to call its specified command for all threads in ascending order.
1248 * Python/Guile scripting
1250 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1251 special section named `.debug_gdb_scripts'.
1253 * New remote packets
1255 qXfer:btrace-conf:read
1256 Return the branch trace configuration for the current thread.
1258 Qbtrace-conf:bts:size
1259 Set the requested ring buffer size for branch tracing in BTS format.
1262 Enable Intel Procesor Trace-based branch tracing for the current
1263 process. The remote stub reports support for this packet to GDB's
1266 Qbtrace-conf:pt:size
1267 Set the requested ring buffer size for branch tracing in Intel Processor
1271 Indicates a memory breakpoint instruction was executed, irrespective
1272 of whether it was GDB that planted the breakpoint or the breakpoint
1273 is hardcoded in the program. This is required for correct non-stop
1277 Indicates the target stopped for a hardware breakpoint. This is
1278 required for correct non-stop mode operation.
1281 Return information about files on the remote system.
1283 qXfer:exec-file:read
1284 Return the full absolute name of the file that was executed to
1285 create a process running on the remote system.
1288 Select the filesystem on which vFile: operations with filename
1289 arguments will operate. This is required for GDB to be able to
1290 access files on remote targets where the remote stub does not
1291 share a common filesystem with the inferior(s).
1294 Indicates that a fork system call was executed.
1297 Indicates that a vfork system call was executed.
1299 vforkdone stop reason
1300 Indicates that a vfork child of the specified process has executed
1301 an exec or exit, allowing the vfork parent to resume execution.
1303 fork-events and vfork-events features in qSupported
1304 The qSupported packet allows GDB to request support for fork and
1305 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1306 and the qSupported response can contain the corresponding
1307 'stubfeatures'. Set and show commands can be used to display
1308 whether these features are enabled.
1310 * Extended-remote fork events
1312 ** GDB now has support for fork events on extended-remote Linux
1313 targets. For targets with Linux kernels 2.5.60 and later, this
1314 enables follow-fork-mode and detach-on-fork for both fork and
1315 vfork, as well as fork and vfork catchpoints.
1317 * The info record command now shows the recording format and the
1318 branch tracing configuration for the current thread when using
1319 the btrace record target.
1320 For the BTS format, it shows the ring buffer size.
1322 * GDB now has support for DTrace USDT (Userland Static Defined
1323 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1325 * GDB now supports access to vector registers on S/390 GNU/Linux
1328 * Removed command line options
1330 -xdb HP-UX XDB compatibility mode.
1332 * Removed targets and native configurations
1334 HP/PA running HP-UX hppa*-*-hpux*
1335 Itanium running HP-UX ia64-*-hpux*
1337 * New configure options
1340 This configure option allows the user to build GDB with support for
1341 Intel Processor Trace (default: auto). This requires libipt.
1343 --with-libipt-prefix=PATH
1344 Specify the path to the version of libipt that GDB should use.
1345 $PATH/include should contain the intel-pt.h header and
1346 $PATH/lib should contain the libipt.so library.
1348 *** Changes in GDB 7.9.1
1352 ** Xmethods can now specify a result type.
1354 *** Changes in GDB 7.9
1356 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1360 ** You can now access frame registers from Python scripts.
1361 ** New attribute 'producer' for gdb.Symtab objects.
1362 ** gdb.Objfile objects have a new attribute "progspace",
1363 which is the gdb.Progspace object of the containing program space.
1364 ** gdb.Objfile objects have a new attribute "owner".
1365 ** gdb.Objfile objects have a new attribute "build_id",
1366 which is the build ID generated when the file was built.
1367 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1368 ** A new event "gdb.clear_objfiles" has been added, triggered when
1369 selecting a new file to debug.
1370 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1371 ** New function gdb.lookup_objfile.
1373 New events which are triggered when GDB modifies the state of the
1376 ** gdb.events.inferior_call_pre: Function call is about to be made.
1377 ** gdb.events.inferior_call_post: Function call has just been made.
1378 ** gdb.events.memory_changed: A memory location has been altered.
1379 ** gdb.events.register_changed: A register has been altered.
1381 * New Python-based convenience functions:
1383 ** $_caller_is(name [, number_of_frames])
1384 ** $_caller_matches(regexp [, number_of_frames])
1385 ** $_any_caller_is(name [, number_of_frames])
1386 ** $_any_caller_matches(regexp [, number_of_frames])
1388 * GDB now supports the compilation and injection of source code into
1389 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1390 to compile the source code to object code, and if successful, inject
1391 and execute that code within the current context of the inferior.
1392 Currently the C language is supported. The commands used to
1393 interface with this new feature are:
1395 compile code [-raw|-r] [--] [source code]
1396 compile file [-raw|-r] filename
1400 demangle [-l language] [--] name
1401 Demangle "name" in the specified language, or the current language
1402 if elided. This command is renamed from the "maint demangle" command.
1403 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1404 as "maint demangler-warning".
1406 queue-signal signal-name-or-number
1407 Queue a signal to be delivered to the thread when it is resumed.
1409 add-auto-load-scripts-directory directory
1410 Add entries to the list of directories from which to load auto-loaded
1413 maint print user-registers
1414 List all currently available "user" registers.
1416 compile code [-r|-raw] [--] [source code]
1417 Compile, inject, and execute in the inferior the executable object
1418 code produced by compiling the provided source code.
1420 compile file [-r|-raw] filename
1421 Compile and inject into the inferior the executable object code
1422 produced by compiling the source code stored in the filename
1425 * On resume, GDB now always passes the signal the program had stopped
1426 for to the thread the signal was sent to, even if the user changed
1427 threads before resuming. Previously GDB would often (but not
1428 always) deliver the signal to the thread that happens to be current
1431 * Conversely, the "signal" command now consistently delivers the
1432 requested signal to the current thread. GDB now asks for
1433 confirmation if the program had stopped for a signal and the user
1434 switched threads meanwhile.
1436 * "breakpoint always-inserted" modes "off" and "auto" merged.
1438 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1439 won't remove breakpoints from the target until all threads stop,
1440 even in non-stop mode. The "auto" mode has been removed, and "off"
1441 is now the default mode.
1445 set debug symbol-lookup
1446 show debug symbol-lookup
1447 Control display of debugging info regarding symbol lookup.
1451 ** The -list-thread-groups command outputs an exit-code field for
1452 inferiors that have exited.
1456 MIPS SDE mips*-sde*-elf*
1460 Support for these obsolete configurations has been removed.
1462 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1463 SGI Irix-5.x mips-*-irix5*
1464 SGI Irix-6.x mips-*-irix6*
1465 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1466 VAX running Ultrix vax-*-ultrix*
1468 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1469 and "assf"), have been removed. Use the "sharedlibrary" command, or
1470 its alias "share", instead.
1472 *** Changes in GDB 7.8
1474 * New command line options
1477 This is an alias for the --data-directory option.
1479 * GDB supports printing and modifying of variable length automatic arrays
1480 as specified in ISO C99.
1482 * The ARM simulator now supports instruction level tracing
1483 with or without disassembly.
1487 GDB now has support for scripting using Guile. Whether this is
1488 available is determined at configure time.
1489 Guile version 2.0 or greater is required.
1490 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1492 * New commands (for set/show, see "New options" below)
1496 Invoke CODE by passing it to the Guile interpreter.
1500 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1502 info auto-load guile-scripts [regexp]
1503 Print the list of automatically loaded Guile scripts.
1505 * The source command is now capable of sourcing Guile scripts.
1506 This feature is dependent on the debugger being built with Guile support.
1510 set print symbol-loading (off|brief|full)
1511 show print symbol-loading
1512 Control whether to print informational messages when loading symbol
1513 information for a file. The default is "full", but when debugging
1514 programs with large numbers of shared libraries the amount of output
1515 becomes less useful.
1517 set guile print-stack (none|message|full)
1518 show guile print-stack
1519 Show a stack trace when an error is encountered in a Guile script.
1521 set auto-load guile-scripts (on|off)
1522 show auto-load guile-scripts
1523 Control auto-loading of Guile script files.
1525 maint ada set ignore-descriptive-types (on|off)
1526 maint ada show ignore-descriptive-types
1527 Control whether the debugger should ignore descriptive types in Ada
1528 programs. The default is not to ignore the descriptive types. See
1529 the user manual for more details on descriptive types and the intended
1530 usage of this option.
1532 set auto-connect-native-target
1534 Control whether GDB is allowed to automatically connect to the
1535 native target for the run, attach, etc. commands when not connected
1536 to any target yet. See also "target native" below.
1538 set record btrace replay-memory-access (read-only|read-write)
1539 show record btrace replay-memory-access
1540 Control what memory accesses are allowed during replay.
1542 maint set target-async (on|off)
1543 maint show target-async
1544 This controls whether GDB targets operate in synchronous or
1545 asynchronous mode. Normally the default is asynchronous, if it is
1546 available; but this can be changed to more easily debug problems
1547 occurring only in synchronous mode.
1549 set mi-async (on|off)
1551 Control whether MI asynchronous mode is preferred. This supersedes
1552 "set target-async" of previous GDB versions.
1554 * "set target-async" is deprecated as a CLI option and is now an alias
1555 for "set mi-async" (only puts MI into async mode).
1557 * Background execution commands (e.g., "c&", "s&", etc.) are now
1558 possible ``out of the box'' if the target supports them. Previously
1559 the user would need to explicitly enable the possibility with the
1560 "set target-async on" command.
1562 * New features in the GDB remote stub, GDBserver
1564 ** New option --debug-format=option1[,option2,...] allows one to add
1565 additional text to each output. At present only timestamps
1566 are supported: --debug-format=timestamps.
1567 Timestamps can also be turned on with the
1568 "monitor set debug-format timestamps" command from GDB.
1570 * The 'record instruction-history' command now starts counting instructions
1571 at one. This also affects the instruction ranges reported by the
1572 'record function-call-history' command when given the /i modifier.
1574 * The command 'record function-call-history' supports a new modifier '/c' to
1575 indent the function names based on their call stack depth.
1576 The fields for the '/i' and '/l' modifier have been reordered.
1577 The source line range is now prefixed with 'at'.
1578 The instruction range is now prefixed with 'inst'.
1579 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1580 "record instruction-history" and "list" commands.
1582 * The ranges given as arguments to the 'record function-call-history' and
1583 'record instruction-history' commands are now inclusive.
1585 * The btrace record target now supports the 'record goto' command.
1586 For locations inside the execution trace, the back trace is computed
1587 based on the information stored in the execution trace.
1589 * The btrace record target supports limited reverse execution and replay.
1590 The target does not record data and therefore does not allow reading
1591 memory or registers.
1593 * The "catch syscall" command now works on s390*-linux* targets.
1595 * The "compare-sections" command is no longer specific to target
1596 remote. It now works with all targets.
1598 * All native targets are now consistently called "native".
1599 Consequently, the "target child", "target GNU", "target djgpp",
1600 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1601 commands have been replaced with "target native". The QNX/NTO port
1602 leaves the "procfs" target in place and adds a "native" target for
1603 consistency with other ports. The impact on users should be minimal
1604 as these commands previously either throwed an error, or were
1605 no-ops. The target's name is visible in the output of the following
1606 commands: "help target", "info target", "info files", "maint print
1609 * The "target native" command now connects to the native target. This
1610 can be used to launch native programs even when "set
1611 auto-connect-native-target" is set to off.
1613 * GDB now supports access to Intel MPX registers on GNU/Linux.
1615 * Support for Intel AVX-512 registers on GNU/Linux.
1616 Support displaying and modifying Intel AVX-512 registers
1617 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1619 * New remote packets
1621 qXfer:btrace:read's annex
1622 The qXfer:btrace:read packet supports a new annex 'delta' to read
1623 branch trace incrementally.
1627 ** Valid Python operations on gdb.Value objects representing
1628 structs/classes invoke the corresponding overloaded operators if
1630 ** New `Xmethods' feature in the Python API. Xmethods are
1631 additional methods or replacements for existing methods of a C++
1632 class. This feature is useful for those cases where a method
1633 defined in C++ source code could be inlined or optimized out by
1634 the compiler, making it unavailable to GDB.
1637 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1639 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1640 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1641 its alias "share", instead.
1643 * The commands "set remotebaud" and "show remotebaud" are no longer
1644 supported. Use "set serial baud" and "show serial baud" (respectively)
1649 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1650 target-async". The latter is left as a deprecated alias of the
1651 former for backward compatibility. If the target supports it,
1652 CLI background execution commands are now always possible by
1653 default, independently of whether the frontend stated a
1654 preference for asynchronous execution with "-gdb-set mi-async".
1655 Previously "-gdb-set target-async off" affected both MI execution
1656 commands and CLI execution commands.
1658 *** Changes in GDB 7.7
1660 * Improved support for process record-replay and reverse debugging on
1661 arm*-linux* targets. Support for thumb32 and syscall instruction
1662 recording has been added.
1664 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1666 * GDB now supports Fission DWP file format version 2.
1667 http://gcc.gnu.org/wiki/DebugFission
1669 * New convenience function "$_isvoid", to check whether an expression
1670 is void. A void expression is an expression where the type of the
1671 result is "void". For example, some convenience variables may be
1672 "void" when evaluated (e.g., "$_exitcode" before the execution of
1673 the program being debugged; or an undefined convenience variable).
1674 Another example, when calling a function whose return type is
1677 * The "maintenance print objfiles" command now takes an optional regexp.
1679 * The "catch syscall" command now works on arm*-linux* targets.
1681 * GDB now consistently shows "<not saved>" when printing values of
1682 registers the debug info indicates have not been saved in the frame
1683 and there's nowhere to retrieve them from
1684 (callee-saved/call-clobbered registers):
1689 (gdb) info registers rax
1692 Before, the former would print "<optimized out>", and the latter
1693 "*value not available*".
1695 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1700 ** Frame filters and frame decorators have been added.
1701 ** Temporary breakpoints are now supported.
1702 ** Line tables representation has been added.
1703 ** New attribute 'parent_type' for gdb.Field objects.
1704 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1705 ** New attribute 'name' for gdb.Type objects.
1709 Nios II ELF nios2*-*-elf
1710 Nios II GNU/Linux nios2*-*-linux
1711 Texas Instruments MSP430 msp430*-*-elf
1713 * Removed native configurations
1715 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1716 been removed. ELF variants of these configurations are kept supported.
1718 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1719 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1720 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1721 i[34567]86-*-openbsd3.[0-3]
1722 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1723 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1724 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1728 Like "catch throw", but catches a re-thrown exception.
1729 maint check-psymtabs
1730 Renamed from old "maint check-symtabs".
1732 Perform consistency checks on symtabs.
1733 maint expand-symtabs
1734 Expand symtabs matching an optional regexp.
1737 Display the details of GDB configure-time options.
1739 maint set|show per-command
1740 maint set|show per-command space
1741 maint set|show per-command time
1742 maint set|show per-command symtab
1743 Enable display of per-command gdb resource usage.
1745 remove-symbol-file FILENAME
1746 remove-symbol-file -a ADDRESS
1747 Remove a symbol file added via add-symbol-file. The file to remove
1748 can be identified by its filename or by an address that lies within
1749 the boundaries of this symbol file in memory.
1752 info exceptions REGEXP
1753 Display the list of Ada exceptions defined in the program being
1754 debugged. If provided, only the exceptions whose names match REGEXP
1759 set debug symfile off|on
1761 Control display of debugging info regarding reading symbol files and
1762 symbol tables within those files
1764 set print raw frame-arguments
1765 show print raw frame-arguments
1766 Set/show whether to print frame arguments in raw mode,
1767 disregarding any defined pretty-printers.
1769 set remote trace-status-packet
1770 show remote trace-status-packet
1771 Set/show the use of remote protocol qTStatus packet.
1775 Control display of debugging messages related to Nios II targets.
1779 Control whether target-assisted range stepping is enabled.
1781 set startup-with-shell
1782 show startup-with-shell
1783 Specifies whether Unix child processes are started via a shell or
1788 Use the target memory cache for accesses to the code segment. This
1789 improves performance of remote debugging (particularly disassembly).
1791 * You can now use a literal value 'unlimited' for options that
1792 interpret 0 or -1 as meaning "unlimited". E.g., "set
1793 trace-buffer-size unlimited" is now an alias for "set
1794 trace-buffer-size -1" and "set height unlimited" is now an alias for
1797 * The "set debug symtab-create" debugging option of GDB has been changed to
1798 accept a verbosity level. 0 means "off", 1 provides basic debugging
1799 output, and values of 2 or greater provides more verbose output.
1801 * New command-line options
1803 Display the details of GDB configure-time options.
1805 * The command 'tsave' can now support new option '-ctf' to save trace
1806 buffer in Common Trace Format.
1808 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1811 * GDB now implements the the C++ 'typeid' operator.
1813 * The new convenience variable $_exception holds the exception being
1814 thrown or caught at an exception-related catchpoint.
1816 * The exception-related catchpoints, like "catch throw", now accept a
1817 regular expression which can be used to filter exceptions by type.
1819 * The new convenience variable $_exitsignal is automatically set to
1820 the terminating signal number when the program being debugged dies
1821 due to an uncaught signal.
1825 ** All MI commands now accept an optional "--language" option.
1826 Support for this feature can be verified by using the "-list-features"
1827 command, which should contain "language-option".
1829 ** The new command -info-gdb-mi-command allows the user to determine
1830 whether a GDB/MI command is supported or not.
1832 ** The "^error" result record returned when trying to execute an undefined
1833 GDB/MI command now provides a variable named "code" whose content is the
1834 "undefined-command" error code. Support for this feature can be verified
1835 by using the "-list-features" command, which should contain
1836 "undefined-command-error-code".
1838 ** The -trace-save MI command can optionally save trace buffer in Common
1841 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1843 ** The command -data-list-register-values now accepts an optional
1844 "--skip-unavailable" option. When used, only the available registers
1847 ** The new command -trace-frame-collected dumps collected variables,
1848 computed expressions, tvars, memory and registers in a traceframe.
1850 ** The commands -stack-list-locals, -stack-list-arguments and
1851 -stack-list-variables now accept an option "--skip-unavailable".
1852 When used, only the available locals or arguments are displayed.
1854 ** The -exec-run command now accepts an optional "--start" option.
1855 When used, the command follows the same semantics as the "start"
1856 command, stopping the program's execution at the start of its
1857 main subprogram. Support for this feature can be verified using
1858 the "-list-features" command, which should contain
1859 "exec-run-start-option".
1861 ** The new commands -catch-assert and -catch-exceptions insert
1862 catchpoints stopping the program when Ada exceptions are raised.
1864 ** The new command -info-ada-exceptions provides the equivalent of
1865 the new "info exceptions" command.
1867 * New system-wide configuration scripts
1868 A GDB installation now provides scripts suitable for use as system-wide
1869 configuration scripts for the following systems:
1873 * GDB now supports target-assigned range stepping with remote targets.
1874 This improves the performance of stepping source lines by reducing
1875 the number of control packets from/to GDB. See "New remote packets"
1878 * GDB now understands the element 'tvar' in the XML traceframe info.
1879 It has the id of the collected trace state variables.
1881 * On S/390 targets that provide the transactional-execution feature,
1882 the program interruption transaction diagnostic block (TDB) is now
1883 represented as a number of additional "registers" in GDB.
1885 * New remote packets
1889 The vCont packet supports a new 'r' action, that tells the remote
1890 stub to step through an address range itself, without GDB
1891 involvemement at each single-step.
1893 qXfer:libraries-svr4:read's annex
1894 The previously unused annex of the qXfer:libraries-svr4:read packet
1895 is now used to support passing an argument list. The remote stub
1896 reports support for this argument list to GDB's qSupported query.
1897 The defined arguments are "start" and "prev", used to reduce work
1898 necessary for library list updating, resulting in significant
1901 * New features in the GDB remote stub, GDBserver
1903 ** GDBserver now supports target-assisted range stepping. Currently
1904 enabled on x86/x86_64 GNU/Linux targets.
1906 ** GDBserver now adds element 'tvar' in the XML in the reply to
1907 'qXfer:traceframe-info:read'. It has the id of the collected
1908 trace state variables.
1910 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1913 * New 'z' formatter for printing and examining memory, this displays the
1914 value as hexadecimal zero padded on the left to the size of the type.
1916 * GDB can now use Windows x64 unwinding data.
1918 * The "set remotebaud" command has been replaced by "set serial baud".
1919 Similarly, "show remotebaud" has been replaced by "show serial baud".
1920 The "set remotebaud" and "show remotebaud" commands are still available
1921 to provide backward compatibility with older versions of GDB.
1923 *** Changes in GDB 7.6
1925 * Target record has been renamed to record-full.
1926 Record/replay is now enabled with the "record full" command.
1927 This also affects settings that are associated with full record/replay
1928 that have been moved from "set/show record" to "set/show record full":
1930 set|show record full insn-number-max
1931 set|show record full stop-at-limit
1932 set|show record full memory-query
1934 * A new record target "record-btrace" has been added. The new target
1935 uses hardware support to record the control-flow of a process. It
1936 does not support replaying the execution, but it implements the
1937 below new commands for investigating the recorded execution log.
1938 This new recording method can be enabled using:
1942 The "record-btrace" target is only available on Intel Atom processors
1943 and requires a Linux kernel 2.6.32 or later.
1945 * Two new commands have been added for record/replay to give information
1946 about the recorded execution without having to replay the execution.
1947 The commands are only supported by "record btrace".
1949 record instruction-history prints the execution history at
1950 instruction granularity
1952 record function-call-history prints the execution history at
1953 function granularity
1955 * New native configurations
1957 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1958 FreeBSD/powerpc powerpc*-*-freebsd
1959 x86_64/Cygwin x86_64-*-cygwin*
1960 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1964 ARM AArch64 aarch64*-*-elf
1965 ARM AArch64 GNU/Linux aarch64*-*-linux
1966 Lynx 178 PowerPC powerpc-*-lynx*178
1967 x86_64/Cygwin x86_64-*-cygwin*
1968 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
1970 * If the configured location of system.gdbinit file (as given by the
1971 --with-system-gdbinit option at configure time) is in the
1972 data-directory (as specified by --with-gdb-datadir at configure
1973 time) or in one of its subdirectories, then GDB will look for the
1974 system-wide init file in the directory specified by the
1975 --data-directory command-line option.
1977 * New command line options:
1979 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
1980 other initialization files, unlike -nx which disables all of them.
1982 * Removed command line options
1984 -epoch This was used by the gdb mode in Epoch, an ancient fork of
1987 * The 'ptype' and 'whatis' commands now accept an argument to control
1990 * 'info proc' now works on some core files.
1994 ** Vectors can be created with gdb.Type.vector.
1996 ** Python's atexit.register now works in GDB.
1998 ** Types can be pretty-printed via a Python API.
2000 ** Python 3 is now supported (in addition to Python 2.4 or later)
2002 ** New class gdb.Architecture exposes GDB's internal representation
2003 of architecture in the Python API.
2005 ** New method Frame.architecture returns the gdb.Architecture object
2006 corresponding to the frame's architecture.
2008 * New Python-based convenience functions:
2010 ** $_memeq(buf1, buf2, length)
2011 ** $_streq(str1, str2)
2013 ** $_regex(str, regex)
2015 * The 'cd' command now defaults to using '~' (the home directory) if not
2018 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2019 default for GCC since November 2000.
2021 * The command 'forward-search' can now be abbreviated as 'fo'.
2023 * The command 'info tracepoints' can now display 'installed on target'
2024 or 'not installed on target' for each non-pending location of tracepoint.
2026 * New configure options
2028 --enable-libmcheck/--disable-libmcheck
2029 By default, development versions are built with -lmcheck on hosts
2030 that support it, in order to help track memory corruption issues.
2031 Release versions, on the other hand, are built without -lmcheck
2032 by default. The --enable-libmcheck/--disable-libmcheck configure
2033 options allow the user to override that default.
2034 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2035 This configure option allows the user to build GDB with
2036 libbabeltrace using which GDB can read Common Trace Format data.
2038 * New commands (for set/show, see "New options" below)
2041 Catch signals. This is similar to "handle", but allows commands and
2042 conditions to be attached.
2045 List the BFDs known to GDB.
2047 python-interactive [command]
2049 Start a Python interactive prompt, or evaluate the optional command
2050 and print the result of expressions.
2053 "py" is a new alias for "python".
2055 enable type-printer [name]...
2056 disable type-printer [name]...
2057 Enable or disable type printers.
2061 ** For the Renesas Super-H architecture, the "regs" command has been removed
2062 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2067 set print type methods (on|off)
2068 show print type methods
2069 Control whether method declarations are displayed by "ptype".
2070 The default is to show them.
2072 set print type typedefs (on|off)
2073 show print type typedefs
2074 Control whether typedef definitions are displayed by "ptype".
2075 The default is to show them.
2077 set filename-display basename|relative|absolute
2078 show filename-display
2079 Control the way in which filenames is displayed.
2080 The default is "relative", which preserves previous behavior.
2082 set trace-buffer-size
2083 show trace-buffer-size
2084 Request target to change the size of trace buffer.
2086 set remote trace-buffer-size-packet auto|on|off
2087 show remote trace-buffer-size-packet
2088 Control the use of the remote protocol `QTBuffer:size' packet.
2092 Control display of debugging messages related to ARM AArch64.
2095 set debug coff-pe-read
2096 show debug coff-pe-read
2097 Control display of debugging messages related to reading of COFF/PE
2102 Control display of debugging messages related to Mach-O symbols
2105 set debug notification
2106 show debug notification
2107 Control display of debugging info for async remote notification.
2111 ** Command parameter changes are now notified using new async record
2112 "=cmd-param-changed".
2113 ** Trace frame changes caused by command "tfind" are now notified using
2114 new async record "=traceframe-changed".
2115 ** The creation, deletion and modification of trace state variables
2116 are now notified using new async records "=tsv-created",
2117 "=tsv-deleted" and "=tsv-modified".
2118 ** The start and stop of process record are now notified using new
2119 async record "=record-started" and "=record-stopped".
2120 ** Memory changes are now notified using new async record
2122 ** The data-disassemble command response will include a "fullname" field
2123 containing the absolute file name when source has been requested.
2124 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2125 command, to allow pattern filling of memory areas.
2126 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2127 library load/unload events.
2128 ** The response to breakpoint commands and breakpoint async records
2129 includes an "installed" field containing a boolean state about each
2130 non-pending tracepoint location is whether installed on target or not.
2131 ** Output of the "-trace-status" command includes a "trace-file" field
2132 containing the name of the trace file being examined. This field is
2133 optional, and only present when examining a trace file.
2134 ** The "fullname" field is now always present along with the "file" field,
2135 even if the file cannot be found by GDB.
2137 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2138 You must have the LZMA library available when configuring GDB for this
2139 feature to be enabled. For more information, see:
2140 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2142 * New remote packets
2145 Set the size of trace buffer. The remote stub reports support for this
2146 packet to gdb's qSupported query.
2149 Enable Branch Trace Store (BTS)-based branch tracing for the current
2150 thread. The remote stub reports support for this packet to gdb's
2154 Disable branch tracing for the current thread. The remote stub reports
2155 support for this packet to gdb's qSupported query.
2158 Read the traced branches for the current thread. The remote stub
2159 reports support for this packet to gdb's qSupported query.
2161 *** Changes in GDB 7.5
2163 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2164 for more x32 ABI info.
2166 * GDB now supports access to MIPS DSP registers on Linux targets.
2168 * GDB now supports debugging microMIPS binaries.
2170 * The "info os" command on GNU/Linux can now display information on
2171 several new classes of objects managed by the operating system:
2172 "info os procgroups" lists process groups
2173 "info os files" lists file descriptors
2174 "info os sockets" lists internet-domain sockets
2175 "info os shm" lists shared-memory regions
2176 "info os semaphores" lists semaphores
2177 "info os msg" lists message queues
2178 "info os modules" lists loaded kernel modules
2180 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2181 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2182 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2183 options and inspect the probe arguments using the new $_probe_arg family
2184 of convenience variables. You can obtain more information about SystemTap
2185 in <http://sourceware.org/systemtap/>.
2187 * GDB now supports reversible debugging on ARM, it allows you to
2188 debug basic ARM and THUMB instructions, and provides
2189 record/replay support.
2191 * The option "symbol-reloading" has been deleted as it is no longer used.
2195 ** GDB commands implemented in Python can now be put in command class
2198 ** The "maint set python print-stack on|off" is now deleted.
2200 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2201 apply "flag enum"-style pretty-printing to any enum.
2203 ** gdb.lookup_symbol can now work when there is no current frame.
2205 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2206 the source at which the symbol was defined.
2208 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2209 method 'value'. The former indicates whether the symbol needs a
2210 frame in order to compute its value, and the latter computes the
2213 ** A new method 'referenced_value' on gdb.Value objects which can
2214 dereference pointer as well as C++ reference values.
2216 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2217 which return the global and static blocks (as gdb.Block objects),
2218 of the underlying symbol table, respectively.
2220 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2221 object associated with a PC value.
2223 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2224 of the address range occupied by code for the current source line.
2226 * Go language support.
2227 GDB now supports debugging programs written in the Go programming
2230 * GDBserver now supports stdio connections.
2231 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2233 * The binary "gdbtui" can no longer be built or installed.
2234 Use "gdb -tui" instead.
2236 * GDB will now print "flag" enums specially. A flag enum is one where
2237 all the enumerator values have no bits in common when pairwise
2238 "and"ed. When printing a value whose type is a flag enum, GDB will
2239 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2240 (gdb) print (enum E) 3
2243 * The filename part of a linespec will now match trailing components
2244 of a source file name. For example, "break gcc/expr.c:1000" will
2245 now set a breakpoint in build/gcc/expr.c, but not
2246 build/libcpp/expr.c.
2248 * The "info proc" and "generate-core-file" commands will now also
2249 work on remote targets connected to GDBserver on Linux.
2251 * The command "info catch" has been removed. It has been disabled
2252 since December 2007.
2254 * The "catch exception" and "catch assert" commands now accept
2255 a condition at the end of the command, much like the "break"
2256 command does. For instance:
2258 (gdb) catch exception Constraint_Error if Barrier = True
2260 Previously, it was possible to add a condition to such catchpoints,
2261 but it had to be done as a second step, after the catchpoint had been
2262 created, using the "condition" command.
2264 * The "info static-tracepoint-marker" command will now also work on
2265 native Linux targets with in-process agent.
2267 * GDB can now set breakpoints on inlined functions.
2269 * The .gdb_index section has been updated to include symbols for
2270 inlined functions. GDB will ignore older .gdb_index sections by
2271 default, which could cause symbol files to be loaded more slowly
2272 until their .gdb_index sections can be recreated. The new command
2273 "set use-deprecated-index-sections on" will cause GDB to use any older
2274 .gdb_index sections it finds. This will restore performance, but the
2275 ability to set breakpoints on inlined functions will be lost in symbol
2276 files with older .gdb_index sections.
2278 The .gdb_index section has also been updated to record more information
2279 about each symbol. This speeds up the "info variables", "info functions"
2280 and "info types" commands when used with programs having the .gdb_index
2281 section, as well as speeding up debugging with shared libraries using
2282 the .gdb_index section.
2284 * Ada support for GDB/MI Variable Objects has been added.
2286 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2291 ** New command -info-os is the MI equivalent of "info os".
2293 ** Output logs ("set logging" and related) now include MI output.
2297 ** "set use-deprecated-index-sections on|off"
2298 "show use-deprecated-index-sections on|off"
2299 Controls the use of deprecated .gdb_index sections.
2301 ** "catch load" and "catch unload" can be used to stop when a shared
2302 library is loaded or unloaded, respectively.
2304 ** "enable count" can be used to auto-disable a breakpoint after
2307 ** "info vtbl" can be used to show the virtual method tables for
2308 C++ and Java objects.
2310 ** "explore" and its sub commands "explore value" and "explore type"
2311 can be used to recursively explore values and types of
2312 expressions. These commands are available only if GDB is
2313 configured with '--with-python'.
2315 ** "info auto-load" shows status of all kinds of auto-loaded files,
2316 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2317 sequences of commands files, "info auto-load python-scripts"
2318 shows status of auto-loading Python script files,
2319 "info auto-load local-gdbinit" shows status of loading init file
2320 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2321 status of inferior specific thread debugging shared library loading.
2323 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2324 and "show auto-load-scripts" commands have been deprecated, use their
2325 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2326 and "show auto-load python-scripts" counterparts instead.
2328 ** "dprintf location,format,args..." creates a dynamic printf, which
2329 is basically a breakpoint that does a printf and immediately
2330 resumes your program's execution, so it is like a printf that you
2331 can insert dynamically at runtime instead of at compiletime.
2333 ** "set print symbol"
2335 Controls whether GDB attempts to display the symbol, if any,
2336 corresponding to addresses it prints. This defaults to "on", but
2337 you can set it to "off" to restore GDB's previous behavior.
2339 * Deprecated commands
2341 ** For the Renesas Super-H architecture, the "regs" command has been
2342 deprecated, and "info all-registers" should be used instead.
2346 Renesas RL78 rl78-*-elf
2347 HP OpenVMS ia64 ia64-hp-openvms*
2349 * GDBserver supports evaluation of breakpoint conditions. When
2350 support is advertised by GDBserver, GDB may be told to send the
2351 breakpoint conditions in bytecode form to GDBserver. GDBserver
2352 will only report the breakpoint trigger to GDB when its condition
2357 set mips compression
2358 show mips compression
2359 Select the compressed ISA encoding used in functions that have no symbol
2360 information available. The encoding can be set to either of:
2363 and is updated automatically from ELF file flags if available.
2365 set breakpoint condition-evaluation
2366 show breakpoint condition-evaluation
2367 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2368 GDBserver ("target"). Default option "auto" chooses the most efficient
2370 This option can improve debugger efficiency depending on the speed of the
2374 Disable auto-loading globally.
2377 Show auto-loading setting of all kinds of auto-loaded files.
2379 set auto-load gdb-scripts on|off
2380 show auto-load gdb-scripts
2381 Control auto-loading of GDB canned sequences of commands files.
2383 set auto-load python-scripts on|off
2384 show auto-load python-scripts
2385 Control auto-loading of Python script files.
2387 set auto-load local-gdbinit on|off
2388 show auto-load local-gdbinit
2389 Control loading of init file (.gdbinit) from current directory.
2391 set auto-load libthread-db on|off
2392 show auto-load libthread-db
2393 Control auto-loading of inferior specific thread debugging shared library.
2395 set auto-load scripts-directory <dir1>[:<dir2>...]
2396 show auto-load scripts-directory
2397 Set a list of directories from which to load auto-loaded scripts.
2398 Automatically loaded Python scripts and GDB scripts are located in one
2399 of the directories listed by this option.
2400 The delimiter (':' above) may differ according to the host platform.
2402 set auto-load safe-path <dir1>[:<dir2>...]
2403 show auto-load safe-path
2404 Set a list of directories from which it is safe to auto-load files.
2405 The delimiter (':' above) may differ according to the host platform.
2407 set debug auto-load on|off
2408 show debug auto-load
2409 Control display of debugging info for auto-loading the files above.
2411 set dprintf-style gdb|call|agent
2413 Control the way in which a dynamic printf is performed; "gdb"
2414 requests a GDB printf command, while "call" causes dprintf to call a
2415 function in the inferior. "agent" requests that the target agent
2416 (such as GDBserver) do the printing.
2418 set dprintf-function <expr>
2419 show dprintf-function
2420 set dprintf-channel <expr>
2421 show dprintf-channel
2422 Set the function and optional first argument to the call when using
2423 the "call" style of dynamic printf.
2425 set disconnected-dprintf on|off
2426 show disconnected-dprintf
2427 Control whether agent-style dynamic printfs continue to be in effect
2428 after GDB disconnects.
2430 * New configure options
2432 --with-auto-load-dir
2433 Configure default value for the 'set auto-load scripts-directory'
2434 setting above. It defaults to '$debugdir:$datadir/auto-load',
2435 $debugdir representing global debugging info directories (available
2436 via 'show debug-file-directory') and $datadir representing GDB's data
2437 directory (available via 'show data-directory').
2439 --with-auto-load-safe-path
2440 Configure default value for the 'set auto-load safe-path' setting
2441 above. It defaults to the --with-auto-load-dir setting.
2443 --without-auto-load-safe-path
2444 Set 'set auto-load safe-path' to '/', effectively disabling this
2447 * New remote packets
2449 z0/z1 conditional breakpoints extension
2451 The z0/z1 breakpoint insertion packets have been extended to carry
2452 a list of conditional expressions over to the remote stub depending on the
2453 condition evaluation mode. The use of this extension can be controlled
2454 via the "set remote conditional-breakpoints-packet" command.
2458 Specify the signals which the remote stub may pass to the debugged
2459 program without GDB involvement.
2461 * New command line options
2463 --init-command=FILE, -ix Like --command, -x but execute it
2464 before loading inferior.
2465 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2466 execute it before loading inferior.
2468 *** Changes in GDB 7.4
2470 * GDB now handles ambiguous linespecs more consistently; the existing
2471 FILE:LINE support has been expanded to other types of linespecs. A
2472 breakpoint will now be set on all matching locations in all
2473 inferiors, and locations will be added or removed according to
2476 * GDB now allows you to skip uninteresting functions and files when
2477 stepping with the "skip function" and "skip file" commands.
2479 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2480 and "show remote hardware-watchpoint-length-limit". These allows to
2481 set or show the maximum length limit (in bytes) of a remote
2482 target hardware watchpoint.
2484 This allows e.g. to use "unlimited" hardware watchpoints with the
2485 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2486 watchpoints are slower than real hardware watchpoints but are
2487 significantly faster than gdb software watchpoints.
2491 ** The register_pretty_printer function in module gdb.printing now takes
2492 an optional `replace' argument. If True, the new printer replaces any
2495 ** The "maint set python print-stack on|off" command has been
2496 deprecated and will be deleted in GDB 7.5.
2497 A new command: "set python print-stack none|full|message" has
2498 replaced it. Additionally, the default for "print-stack" is
2499 now "message", which just prints the error message without
2502 ** A prompt substitution hook (prompt_hook) is now available to the
2505 ** A new Python module, gdb.prompt has been added to the GDB Python
2506 modules library. This module provides functionality for
2507 escape sequences in prompts (used by set/show
2508 extended-prompt). These escape sequences are replaced by their
2509 corresponding value.
2511 ** Python commands and convenience-functions located in
2512 'data-directory'/python/gdb/command and
2513 'data-directory'/python/gdb/function are now automatically loaded
2516 ** Blocks now provide four new attributes. global_block and
2517 static_block will return the global and static blocks
2518 respectively. is_static and is_global are boolean attributes
2519 that indicate if the block is one of those two types.
2521 ** Symbols now provide the "type" attribute, the type of the symbol.
2523 ** The "gdb.breakpoint" function has been deprecated in favor of
2526 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2527 of a function. This class is based on the "finish" command
2528 available in the CLI.
2530 ** Type objects for struct and union types now allow access to
2531 the fields using standard Python dictionary (mapping) methods.
2532 For example, "some_type['myfield']" now works, as does
2533 "some_type.items()".
2535 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2538 ** A new function, "deep_items" has been added to the gdb.types
2539 module in the GDB Python modules library. This function returns
2540 an iterator over the fields of a struct or union type. Unlike
2541 the standard Python "iteritems" method, it will recursively traverse
2542 any anonymous fields.
2546 ** "*stopped" events can report several new "reason"s, such as
2549 ** Breakpoint changes are now notified using new async records, like
2550 "=breakpoint-modified".
2552 ** New command -ada-task-info.
2554 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2555 $sdir specifies the default system locations of shared libraries.
2556 $pdir specifies the directory where the libpthread used by the application
2559 GDB no longer looks in $sdir and $pdir after it has searched the directories
2560 mentioned in libthread-db-search-path. If you want to search those
2561 directories, they must be specified in libthread-db-search-path.
2562 The default value of libthread-db-search-path on GNU/Linux and Solaris
2563 systems is now "$sdir:$pdir".
2565 $pdir is not supported by gdbserver, it is currently ignored.
2566 $sdir is supported by gdbserver.
2568 * New configure option --with-iconv-bin.
2569 When using the internationalization support like the one in the GNU C
2570 library, GDB will invoke the "iconv" program to get a list of supported
2571 character sets. If this program lives in a non-standard location, one can
2572 use this option to specify where to find it.
2574 * When natively debugging programs on PowerPC BookE processors running
2575 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2576 watchpoints, which specify a mask in addition to an address to watch.
2577 The mask specifies that some bits of an address (the bits which are
2578 reset in the mask) should be ignored when matching the address accessed
2579 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2580 section in the user manual for more details.
2582 * The new option --once causes GDBserver to stop listening for connections once
2583 the first connection is made. The listening port used by GDBserver will
2584 become available after that.
2586 * New commands "info macros" and "alias" have been added.
2588 * New function parameters suffix @entry specifies value of function parameter
2589 at the time the function got called. Entry values are available only since
2595 "!" is now an alias of the "shell" command.
2596 Note that no space is needed between "!" and SHELL COMMAND.
2600 watch EXPRESSION mask MASK_VALUE
2601 The watch command now supports the mask argument which allows creation
2602 of masked watchpoints, if the current architecture supports this feature.
2604 info auto-load-scripts [REGEXP]
2605 This command was formerly named "maintenance print section-scripts".
2606 It is now generally useful and is no longer a maintenance-only command.
2608 info macro [-all] [--] MACRO
2609 The info macro command has new options `-all' and `--'. The first for
2610 printing all definitions of a macro. The second for explicitly specifying
2611 the end of arguments and the beginning of the macro name in case the macro
2612 name starts with a hyphen.
2614 collect[/s] EXPRESSIONS
2615 The tracepoint collect command now takes an optional modifier "/s"
2616 that directs it to dereference pointer-to-character types and
2617 collect the bytes of memory up to a zero byte. The behavior is
2618 similar to what you see when you use the regular print command on a
2619 string. An optional integer following the "/s" sets a bound on the
2620 number of bytes that will be collected.
2623 The trace start command now interprets any supplied arguments as a
2624 note to be recorded with the trace run, with an effect similar to
2625 setting the variable trace-notes.
2628 The trace stop command now interprets any arguments as a note to be
2629 mentioned along with the tstatus report that the trace was stopped
2630 with a command. The effect is similar to setting the variable
2633 * Tracepoints can now be enabled and disabled at any time after a trace
2634 experiment has been started using the standard "enable" and "disable"
2635 commands. It is now possible to start a trace experiment with no enabled
2636 tracepoints; GDB will display a warning, but will allow the experiment to
2637 begin, assuming that tracepoints will be enabled as needed while the trace
2640 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2641 locations with 4-byte instructions, when they were previously
2642 limited to locations with instructions of 5 bytes or longer.
2646 set debug dwarf2-read
2647 show debug dwarf2-read
2648 Turns on or off display of debugging messages related to reading
2649 DWARF debug info. The default is off.
2651 set debug symtab-create
2652 show debug symtab-create
2653 Turns on or off display of debugging messages related to symbol table
2654 creation. The default is off.
2657 show extended-prompt
2658 Set the GDB prompt, and allow escape sequences to be inserted to
2659 display miscellaneous information (see 'help set extended-prompt'
2660 for the list of sequences). This prompt (and any information
2661 accessed through the escape sequences) is updated every time the
2662 prompt is displayed.
2664 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2665 show print entry-values
2666 Set printing of frame argument values at function entry. In some cases
2667 GDB can determine the value of function argument which was passed by the
2668 function caller, even if the value was modified inside the called function.
2670 set debug entry-values
2671 show debug entry-values
2672 Control display of debugging info for determining frame argument values at
2673 function entry and virtual tail call frames.
2675 set basenames-may-differ
2676 show basenames-may-differ
2677 Set whether a source file may have multiple base names.
2678 (A "base name" is the name of a file with the directory part removed.
2679 Example: The base name of "/home/user/hello.c" is "hello.c".)
2680 If set, GDB will canonicalize file names (e.g., expand symlinks)
2681 before comparing them. Canonicalization is an expensive operation,
2682 but it allows the same file be known by more than one base name.
2683 If not set (the default), all source files are assumed to have just
2684 one base name, and gdb will do file name comparisons more efficiently.
2690 Set a user name and notes for the current and any future trace runs.
2691 This is useful for long-running and/or disconnected traces, to
2692 inform others (or yourself) as to who is running the trace, supply
2693 contact information, or otherwise explain what is going on.
2695 set trace-stop-notes
2696 show trace-stop-notes
2697 Set a note attached to the trace run, that is displayed when the
2698 trace has been stopped by a tstop command. This is useful for
2699 instance as an explanation, if you are stopping a trace run that was
2700 started by someone else.
2702 * New remote packets
2706 Dynamically enable a tracepoint in a started trace experiment.
2710 Dynamically disable a tracepoint in a started trace experiment.
2714 Set the user and notes of the trace run.
2718 Query the current status of a tracepoint.
2722 Query the minimum length of instruction at which a fast tracepoint may
2725 * Dcache size (number of lines) and line-size are now runtime-configurable
2726 via "set dcache line" and "set dcache line-size" commands.
2730 Texas Instruments TMS320C6x tic6x-*-*
2734 Renesas RL78 rl78-*-elf
2736 *** Changes in GDB 7.3.1
2738 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2740 *** Changes in GDB 7.3
2742 * GDB has a new command: "thread find [REGEXP]".
2743 It finds the thread id whose name, target id, or thread extra info
2744 matches the given regular expression.
2746 * The "catch syscall" command now works on mips*-linux* targets.
2748 * The -data-disassemble MI command now supports modes 2 and 3 for
2749 dumping the instruction opcodes.
2751 * New command line options
2753 -data-directory DIR Specify DIR as the "data-directory".
2754 This is mostly for testing purposes.
2756 * The "maint set python auto-load on|off" command has been renamed to
2757 "set auto-load-scripts on|off".
2759 * GDB has a new command: "set directories".
2760 It is like the "dir" command except that it replaces the
2761 source path list instead of augmenting it.
2763 * GDB now understands thread names.
2765 On GNU/Linux, "info threads" will display the thread name as set by
2766 prctl or pthread_setname_np.
2768 There is also a new command, "thread name", which can be used to
2769 assign a name internally for GDB to display.
2772 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2773 has been integrated into GDB.
2777 ** The function gdb.Write now accepts an optional keyword 'stream'.
2778 This keyword, when provided, will direct the output to either
2779 stdout, stderr, or GDB's logging output.
2781 ** Parameters can now be be sub-classed in Python, and in particular
2782 you may implement the get_set_doc and get_show_doc functions.
2783 This improves how Parameter set/show documentation is processed
2784 and allows for more dynamic content.
2786 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2787 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2788 have an is_valid method.
2790 ** Breakpoints can now be sub-classed in Python, and in particular
2791 you may implement a 'stop' function that is executed each time
2792 the inferior reaches that breakpoint.
2794 ** New function gdb.lookup_global_symbol looks up a global symbol.
2796 ** GDB values in Python are now callable if the value represents a
2797 function. For example, if 'some_value' represents a function that
2798 takes two integer parameters and returns a value, you can call
2799 that function like so:
2801 result = some_value (10,20)
2803 ** Module gdb.types has been added.
2804 It contains a collection of utilities for working with gdb.Types objects:
2805 get_basic_type, has_field, make_enum_dict.
2807 ** Module gdb.printing has been added.
2808 It contains utilities for writing and registering pretty-printers.
2809 New classes: PrettyPrinter, SubPrettyPrinter,
2810 RegexpCollectionPrettyPrinter.
2811 New function: register_pretty_printer.
2813 ** New commands "info pretty-printers", "enable pretty-printer" and
2814 "disable pretty-printer" have been added.
2816 ** gdb.parameter("directories") is now available.
2818 ** New function gdb.newest_frame returns the newest frame in the
2821 ** The gdb.InferiorThread class has a new "name" attribute. This
2822 holds the thread's name.
2824 ** Python Support for Inferior events.
2825 Python scripts can add observers to be notified of events
2826 occurring in the process being debugged.
2827 The following events are currently supported:
2828 - gdb.events.cont Continue event.
2829 - gdb.events.exited Inferior exited event.
2830 - gdb.events.stop Signal received, and Breakpoint hit events.
2834 ** GDB now puts template parameters in scope when debugging in an
2835 instantiation. For example, if you have:
2837 template<int X> int func (void) { return X; }
2839 then if you step into func<5>, "print X" will show "5". This
2840 feature requires proper debuginfo support from the compiler; it
2841 was added to GCC 4.5.
2843 ** The motion commands "next", "finish", "until", and "advance" now
2844 work better when exceptions are thrown. In particular, GDB will
2845 no longer lose control of the inferior; instead, the GDB will
2846 stop the inferior at the point at which the exception is caught.
2847 This functionality requires a change in the exception handling
2848 code that was introduced in GCC 4.5.
2850 * GDB now follows GCC's rules on accessing volatile objects when
2851 reading or writing target state during expression evaluation.
2852 One notable difference to prior behavior is that "print x = 0"
2853 no longer generates a read of x; the value of the assignment is
2854 now always taken directly from the value being assigned.
2856 * GDB now has some support for using labels in the program's source in
2857 linespecs. For instance, you can use "advance label" to continue
2858 execution to a label.
2860 * GDB now has support for reading and writing a new .gdb_index
2861 section. This section holds a fast index of DWARF debugging
2862 information and can be used to greatly speed up GDB startup and
2863 operation. See the documentation for `save gdb-index' for details.
2865 * The "watch" command now accepts an optional "-location" argument.
2866 When used, this causes GDB to watch the memory referred to by the
2867 expression. Such a watchpoint is never deleted due to it going out
2870 * GDB now supports thread debugging of core dumps on GNU/Linux.
2872 GDB now activates thread debugging using the libthread_db library
2873 when debugging GNU/Linux core dumps, similarly to when debugging
2874 live processes. As a result, when debugging a core dump file, GDB
2875 is now able to display pthread_t ids of threads. For example, "info
2876 threads" shows the same output as when debugging the process when it
2877 was live. In earlier releases, you'd see something like this:
2880 * 1 LWP 6780 main () at main.c:10
2882 While now you see this:
2885 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2887 It is also now possible to inspect TLS variables when debugging core
2890 When debugging a core dump generated on a machine other than the one
2891 used to run GDB, you may need to point GDB at the correct
2892 libthread_db library with the "set libthread-db-search-path"
2893 command. See the user manual for more details on this command.
2895 * When natively debugging programs on PowerPC BookE processors running
2896 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2897 which stop execution of the inferior whenever it executes an instruction
2898 at any address within the specified range. See the "PowerPC Embedded"
2899 section in the user manual for more details.
2901 * New features in the GDB remote stub, GDBserver
2903 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2904 and i686 LynxOS (version 5.x).
2906 ** GDBserver is now supported on Blackfin Linux.
2908 * New native configurations
2910 ia64 HP-UX ia64-*-hpux*
2914 Analog Devices, Inc. Blackfin Processor bfin-*
2916 * Ada task switching is now supported on sparc-elf targets when
2917 debugging a program using the Ravenscar Profile. For more information,
2918 see the "Tasking Support when using the Ravenscar Profile" section
2919 in the GDB user manual.
2921 * Guile support was removed.
2923 * New features in the GNU simulator
2925 ** The --map-info flag lists all known core mappings.
2927 ** CFI flashes may be simulated via the "cfi" device.
2929 *** Changes in GDB 7.2
2931 * Shared library support for remote targets by default
2933 When GDB is configured for a generic, non-OS specific target, like
2934 for example, --target=arm-eabi or one of the many *-*-elf targets,
2935 GDB now queries remote stubs for loaded shared libraries using the
2936 `qXfer:libraries:read' packet. Previously, shared library support
2937 was always disabled for such configurations.
2941 ** Argument Dependent Lookup (ADL)
2943 In C++ ADL lookup directs function search to the namespaces of its
2944 arguments even if the namespace has not been imported.
2954 Here the compiler will search for `foo' in the namespace of 'b'
2955 and find A::foo. GDB now supports this. This construct is commonly
2956 used in the Standard Template Library for operators.
2958 ** Improved User Defined Operator Support
2960 In addition to member operators, GDB now supports lookup of operators
2961 defined in a namespace and imported with a `using' directive, operators
2962 defined in the global scope, operators imported implicitly from an
2963 anonymous namespace, and the ADL operators mentioned in the previous
2965 GDB now also supports proper overload resolution for all the previously
2966 mentioned flavors of operators.
2968 ** static const class members
2970 Printing of static const class members that are initialized in the
2971 class definition has been fixed.
2973 * Windows Thread Information Block access.
2975 On Windows targets, GDB now supports displaying the Windows Thread
2976 Information Block (TIB) structure. This structure is visible either
2977 by using the new command `info w32 thread-information-block' or, by
2978 dereferencing the new convenience variable named `$_tlb', a
2979 thread-specific pointer to the TIB. This feature is also supported
2980 when remote debugging using GDBserver.
2982 * Static tracepoints
2984 Static tracepoints are calls in the user program into a tracing
2985 library. One such library is a port of the LTTng kernel tracer to
2986 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
2987 When debugging with GDBserver, GDB now supports combining the GDB
2988 tracepoint machinery with such libraries. For example: the user can
2989 use GDB to probe a static tracepoint marker (a call from the user
2990 program into the tracing library) with the new "strace" command (see
2991 "New commands" below). This creates a "static tracepoint" in the
2992 breakpoint list, that can be manipulated with the same feature set
2993 as fast and regular tracepoints. E.g., collect registers, local and
2994 global variables, collect trace state variables, and define
2995 tracepoint conditions. In addition, the user can collect extra
2996 static tracepoint marker specific data, by collecting the new
2997 $_sdata internal variable. When analyzing the trace buffer, you can
2998 inspect $_sdata like any other variable available to GDB. For more
2999 information, see the "Tracepoints" chapter in GDB user manual. New
3000 remote packets have been defined to support static tracepoints, see
3001 the "New remote packets" section below.
3003 * Better reconstruction of tracepoints after disconnected tracing
3005 GDB will attempt to download the original source form of tracepoint
3006 definitions when starting a trace run, and then will upload these
3007 upon reconnection to the target, resulting in a more accurate
3008 reconstruction of the tracepoints that are in use on the target.
3012 You can now exercise direct control over the ways that GDB can
3013 affect your program. For instance, you can disallow the setting of
3014 breakpoints, so that the program can run continuously (assuming
3015 non-stop mode). In addition, the "observer" variable is available
3016 to switch all of the different controls; in observer mode, GDB
3017 cannot affect the target's behavior at all, which is useful for
3018 tasks like diagnosing live systems in the field.
3020 * The new convenience variable $_thread holds the number of the
3023 * New remote packets
3027 Return the address of the Windows Thread Information Block of a given thread.
3031 In response to several of the tracepoint packets, the target may now
3032 also respond with a number of intermediate `qRelocInsn' request
3033 packets before the final result packet, to have GDB handle
3034 relocating an instruction to execute at a different address. This
3035 is particularly useful for stubs that support fast tracepoints. GDB
3036 reports support for this feature in the qSupported packet.
3040 List static tracepoint markers in the target program.
3044 List static tracepoint markers at a given address in the target
3047 qXfer:statictrace:read
3049 Read the static trace data collected (by a `collect $_sdata'
3050 tracepoint action). The remote stub reports support for this packet
3051 to gdb's qSupported query.
3055 Send the current settings of GDB's permission flags.
3059 Send part of the source (textual) form of a tracepoint definition,
3060 which includes location, conditional, and action list.
3062 * The source command now accepts a -s option to force searching for the
3063 script in the source search path even if the script name specifies
3066 * New features in the GDB remote stub, GDBserver
3068 - GDBserver now support tracepoints (including fast tracepoints, and
3069 static tracepoints). The feature is currently supported by the
3070 i386-linux and amd64-linux builds. See the "Tracepoints support
3071 in gdbserver" section in the manual for more information.
3073 GDBserver JIT compiles the tracepoint's conditional agent
3074 expression bytecode into native code whenever possible for low
3075 overhead dynamic tracepoints conditionals. For such tracepoints,
3076 an expression that examines program state is evaluated when the
3077 tracepoint is reached, in order to determine whether to capture
3078 trace data. If the condition is simple and false, processing the
3079 tracepoint finishes very quickly and no data is gathered.
3081 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3082 for static tracepoints support.
3084 - GDBserver now supports x86_64 Windows 64-bit debugging.
3086 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3087 it understands register description.
3089 * The --batch flag now disables pagination and queries.
3091 * X86 general purpose registers
3093 GDB now supports reading/writing byte, word and double-word x86
3094 general purpose registers directly. This means you can use, say,
3095 $ah or $ax to refer, respectively, to the byte register AH and
3096 16-bit word register AX that are actually portions of the 32-bit
3097 register EAX or 64-bit register RAX.
3099 * The `commands' command now accepts a range of breakpoints to modify.
3100 A plain `commands' following a command that creates multiple
3101 breakpoints affects all the breakpoints set by that command. This
3102 applies to breakpoints set by `rbreak', and also applies when a
3103 single `break' command creates multiple breakpoints (e.g.,
3104 breakpoints on overloaded c++ functions).
3106 * The `rbreak' command now accepts a filename specification as part of
3107 its argument, limiting the functions selected by the regex to those
3108 in the specified file.
3110 * Support for remote debugging Windows and SymbianOS shared libraries
3111 from Unix hosts has been improved. Non Windows GDB builds now can
3112 understand target reported file names that follow MS-DOS based file
3113 system semantics, such as file names that include drive letters and
3114 use the backslash character as directory separator. This makes it
3115 possible to transparently use the "set sysroot" and "set
3116 solib-search-path" on Unix hosts to point as host copies of the
3117 target's shared libraries. See the new command "set
3118 target-file-system-kind" described below, and the "Commands to
3119 specify files" section in the user manual for more information.
3123 eval template, expressions...
3124 Convert the values of one or more expressions under the control
3125 of the string template to a command line, and call it.
3127 set target-file-system-kind unix|dos-based|auto
3128 show target-file-system-kind
3129 Set or show the assumed file system kind for target reported file
3132 save breakpoints <filename>
3133 Save all current breakpoint definitions to a file suitable for use
3134 in a later debugging session. To read the saved breakpoint
3135 definitions, use the `source' command.
3137 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3140 info static-tracepoint-markers
3141 Display information about static tracepoint markers in the target.
3143 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3144 Define a static tracepoint by probing a marker at the given
3145 function, line, address, or marker ID.
3149 Enable and disable observer mode.
3151 set may-write-registers on|off
3152 set may-write-memory on|off
3153 set may-insert-breakpoints on|off
3154 set may-insert-tracepoints on|off
3155 set may-insert-fast-tracepoints on|off
3156 set may-interrupt on|off
3157 Set individual permissions for GDB effects on the target. Note that
3158 some of these settings can have undesirable or surprising
3159 consequences, particularly when changed in the middle of a session.
3160 For instance, disabling the writing of memory can prevent
3161 breakpoints from being inserted, cause single-stepping to fail, or
3162 even crash your program, if you disable after breakpoints have been
3163 inserted. However, GDB should not crash.
3165 set record memory-query on|off
3166 show record memory-query
3167 Control whether to stop the inferior if memory changes caused
3168 by an instruction cannot be recorded.
3173 The disassemble command now supports "start,+length" form of two arguments.
3177 ** GDB now provides a new directory location, called the python directory,
3178 where Python scripts written for GDB can be installed. The location
3179 of that directory is <data-directory>/python, where <data-directory>
3180 is the GDB data directory. For more details, see section `Scripting
3181 GDB using Python' in the manual.
3183 ** The GDB Python API now has access to breakpoints, symbols, symbol
3184 tables, program spaces, inferiors, threads and frame's code blocks.
3185 Additionally, GDB Parameters can now be created from the API, and
3186 manipulated via set/show in the CLI.
3188 ** New functions gdb.target_charset, gdb.target_wide_charset,
3189 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3191 ** New exception gdb.GdbError.
3193 ** Pretty-printers are now also looked up in the current program space.
3195 ** Pretty-printers can now be individually enabled and disabled.
3197 ** GDB now looks for names of Python scripts to auto-load in a
3198 special section named `.debug_gdb_scripts', in addition to looking
3199 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3201 * Tracepoint actions were unified with breakpoint commands. In particular,
3202 there are no longer differences in "info break" output for breakpoints and
3203 tracepoints and the "commands" command can be used for both tracepoints and
3204 regular breakpoints.
3208 ARM Symbian arm*-*-symbianelf*
3210 * D language support.
3211 GDB now supports debugging programs written in the D programming
3214 * GDB now supports the extended ptrace interface for PowerPC which is
3215 available since Linux kernel version 2.6.34. This automatically enables
3216 any hardware breakpoints and additional hardware watchpoints available in
3217 the processor. The old ptrace interface exposes just one hardware
3218 watchpoint and no hardware breakpoints.
3220 * GDB is now able to use the Data Value Compare (DVC) register available on
3221 embedded PowerPC processors to implement in hardware simple watchpoint
3222 conditions of the form:
3224 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3226 This works in native GDB running on Linux kernels with the extended ptrace
3227 interface mentioned above.
3229 *** Changes in GDB 7.1
3233 ** Namespace Support
3235 GDB now supports importing of namespaces in C++. This enables the
3236 user to inspect variables from imported namespaces. Support for
3237 namepace aliasing has also been added. So, if a namespace is
3238 aliased in the current scope (e.g. namepace C=A; ) the user can
3239 print variables using the alias (e.g. (gdb) print C::x).
3243 All known bugs relating to the printing of virtual base class were
3244 fixed. It is now possible to call overloaded static methods using a
3249 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3250 and reinterpret_cast<> are now handled by the C++ expression parser.
3254 Xilinx MicroBlaze microblaze-*-*
3259 Xilinx MicroBlaze microblaze
3262 * Multi-program debugging.
3264 GDB now has support for multi-program (a.k.a. multi-executable or
3265 multi-exec) debugging. This allows for debugging multiple inferiors
3266 simultaneously each running a different program under the same GDB
3267 session. See "Debugging Multiple Inferiors and Programs" in the
3268 manual for more information. This implied some user visible changes
3269 in the multi-inferior support. For example, "info inferiors" now
3270 lists inferiors that are not running yet or that have exited
3271 already. See also "New commands" and "New options" below.
3273 * New tracing features
3275 GDB's tracepoint facility now includes several new features:
3277 ** Trace state variables
3279 GDB tracepoints now include support for trace state variables, which
3280 are variables managed by the target agent during a tracing
3281 experiment. They are useful for tracepoints that trigger each
3282 other, so for instance one tracepoint can count hits in a variable,
3283 and then a second tracepoint has a condition that is true when the
3284 count reaches a particular value. Trace state variables share the
3285 $-syntax of GDB convenience variables, and can appear in both
3286 tracepoint actions and condition expressions. Use the "tvariable"
3287 command to create, and "info tvariables" to view; see "Trace State
3288 Variables" in the manual for more detail.
3292 GDB now includes an option for defining fast tracepoints, which
3293 targets may implement more efficiently, such as by installing a jump
3294 into the target agent rather than a trap instruction. The resulting
3295 speedup can be by two orders of magnitude or more, although the
3296 tradeoff is that some program locations on some target architectures
3297 might not allow fast tracepoint installation, for instance if the
3298 instruction to be replaced is shorter than the jump. To request a
3299 fast tracepoint, use the "ftrace" command, with syntax identical to
3300 the regular trace command.
3302 ** Disconnected tracing
3304 It is now possible to detach GDB from the target while it is running
3305 a trace experiment, then reconnect later to see how the experiment
3306 is going. In addition, a new variable disconnected-tracing lets you
3307 tell the target agent whether to continue running a trace if the
3308 connection is lost unexpectedly.
3312 GDB now has the ability to save the trace buffer into a file, and
3313 then use that file as a target, similarly to you can do with
3314 corefiles. You can select trace frames, print data that was
3315 collected in them, and use tstatus to display the state of the
3316 tracing run at the moment that it was saved. To create a trace
3317 file, use "tsave <filename>", and to use it, do "target tfile
3320 ** Circular trace buffer
3322 You can ask the target agent to handle the trace buffer as a
3323 circular buffer, discarding the oldest trace frames to make room for
3324 newer ones, by setting circular-trace-buffer to on. This feature may
3325 not be available for all target agents.
3330 The disassemble command, when invoked with two arguments, now requires
3331 the arguments to be comma-separated.
3334 The info variables command now displays variable definitions. Files
3335 which only declare a variable are not shown.
3338 The source command is now capable of sourcing Python scripts.
3339 This feature is dependent on the debugger being build with Python
3342 Related to this enhancement is also the introduction of a new command
3343 "set script-extension" (see below).
3345 * New commands (for set/show, see "New options" below)
3347 record save [<FILENAME>]
3348 Save a file (in core file format) containing the process record
3349 execution log for replay debugging at a later time.
3351 record restore <FILENAME>
3352 Restore the process record execution log that was saved at an
3353 earlier time, for replay debugging.
3355 add-inferior [-copies <N>] [-exec <FILENAME>]
3358 clone-inferior [-copies <N>] [ID]
3359 Make a new inferior ready to execute the same program another
3360 inferior has loaded.
3365 maint info program-spaces
3366 List the program spaces loaded into GDB.
3368 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3369 show remote interrupt-sequence
3370 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3371 as the sequence to the remote target in order to interrupt the execution.
3372 Ctrl-C is a default. Some system prefers BREAK which is high level of
3373 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3374 Magic SysRq g. It is BREAK signal and character 'g'.
3376 set remote interrupt-on-connect [on | off]
3377 show remote interrupt-on-connect
3378 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3379 remote target when gdb connects to it. This is needed when you debug
3382 set remotebreak [on | off]
3384 Deprecated. Use "set/show remote interrupt-sequence" instead.
3386 tvariable $NAME [ = EXP ]
3387 Create or modify a trace state variable.
3390 List trace state variables and their values.
3392 delete tvariable $NAME ...
3393 Delete one or more trace state variables.
3396 Evaluate the given expressions without collecting anything into the
3397 trace buffer. (Valid in tracepoint actions only.)
3399 ftrace FN / FILE:LINE / *ADDR
3400 Define a fast tracepoint at the given function, line, or address.
3402 * New expression syntax
3404 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3405 GDB now parses 0b101010 identically with 42.
3409 set follow-exec-mode new|same
3410 show follow-exec-mode
3411 Control whether GDB reuses the same inferior across an exec call or
3412 creates a new one. This is useful to be able to restart the old
3413 executable after the inferior having done an exec call.
3415 set default-collect EXPR, ...
3416 show default-collect
3417 Define a list of expressions to be collected at each tracepoint.
3418 This is a useful way to ensure essential items are not overlooked,
3419 such as registers or a critical global variable.
3421 set disconnected-tracing
3422 show disconnected-tracing
3423 If set to 1, the target is instructed to continue tracing if it
3424 loses its connection to GDB. If 0, the target is to stop tracing
3427 set circular-trace-buffer
3428 show circular-trace-buffer
3429 If set to on, the target is instructed to use a circular trace buffer
3430 and discard the oldest trace frames instead of stopping the trace due
3431 to a full trace buffer. If set to off, the trace stops when the buffer
3432 fills up. Some targets may not support this.
3434 set script-extension off|soft|strict
3435 show script-extension
3436 If set to "off", the debugger does not perform any script language
3437 recognition, and all sourced files are assumed to be GDB scripts.
3438 If set to "soft" (the default), files are sourced according to
3439 filename extension, falling back to GDB scripts if the first
3441 If set to "strict", files are sourced according to filename extension.
3443 set ada trust-PAD-over-XVS on|off
3444 show ada trust-PAD-over-XVS
3445 If off, activate a workaround against a bug in the debugging information
3446 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3447 the GCC sources for more information about the GNAT encoding and
3448 PAD types in particular). It is always safe to set this option to
3449 off, but this introduces a slight performance penalty. The default
3452 * Python API Improvements
3454 ** GDB provides the new class gdb.LazyString. This is useful in
3455 some pretty-printing cases. The new method gdb.Value.lazy_string
3456 provides a simple way to create objects of this type.
3458 ** The fields returned by gdb.Type.fields now have an
3459 `is_base_class' attribute.
3461 ** The new method gdb.Type.range returns the range of an array type.
3463 ** The new method gdb.parse_and_eval can be used to parse and
3464 evaluate an expression.
3466 * New remote packets
3469 Define a trace state variable.
3472 Get the current value of a trace state variable.
3475 Set desired tracing behavior upon disconnection.
3478 Set the trace buffer to be linear or circular.
3481 Get data about the tracepoints currently in use.
3485 Process record now works correctly with hardware watchpoints.
3487 Multiple bug fixes have been made to the mips-irix port, making it
3488 much more reliable. In particular:
3489 - Debugging threaded applications is now possible again. Previously,
3490 GDB would hang while starting the program, or while waiting for
3491 the program to stop at a breakpoint.
3492 - Attaching to a running process no longer hangs.
3493 - An error occurring while loading a core file has been fixed.
3494 - Changing the value of the PC register now works again. This fixes
3495 problems observed when using the "jump" command, or when calling
3496 a function from GDB, or even when assigning a new value to $pc.
3497 - With the "finish" and "return" commands, the return value for functions
3498 returning a small array is now correctly printed.
3499 - It is now possible to break on shared library code which gets executed
3500 during a shared library init phase (code executed while executing
3501 their .init section). Previously, the breakpoint would have no effect.
3502 - GDB is now able to backtrace through the signal handler for
3503 non-threaded programs.
3505 PIE (Position Independent Executable) programs debugging is now supported.
3506 This includes debugging execution of PIC (Position Independent Code) shared
3507 libraries although for that, it should be possible to run such libraries as an
3510 *** Changes in GDB 7.0
3512 * GDB now has an interface for JIT compilation. Applications that
3513 dynamically generate code can create symbol files in memory and register
3514 them with GDB. For users, the feature should work transparently, and
3515 for JIT developers, the interface is documented in the GDB manual in the
3516 "JIT Compilation Interface" chapter.
3518 * Tracepoints may now be conditional. The syntax is as for
3519 breakpoints; either an "if" clause appended to the "trace" command,
3520 or the "condition" command is available. GDB sends the condition to
3521 the target for evaluation using the same bytecode format as is used
3522 for tracepoint actions.
3524 * The disassemble command now supports: an optional /r modifier, print the
3525 raw instructions in hex as well as in symbolic form, and an optional /m
3526 modifier to print mixed source+assembly.
3528 * Process record and replay
3530 In a architecture environment that supports ``process record and
3531 replay'', ``process record and replay'' target can record a log of
3532 the process execution, and replay it with both forward and reverse
3535 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3536 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3537 set execution-direction {forward|reverse}, for targets that support
3540 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3541 feature is available with a native GDB running on kernel version
3544 * GDB now has support for multi-byte and wide character sets on the
3545 target. Strings whose character type is wchar_t, char16_t, or
3546 char32_t are now correctly printed. GDB supports wide- and unicode-
3547 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3548 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3549 `printf'. This feature requires iconv to work properly; if your
3550 system does not have a working iconv, GDB can use GNU libiconv. See
3551 the installation instructions for more information.
3553 * GDB now supports automatic retrieval of shared library files from
3554 remote targets. To use this feature, specify a system root that begins
3555 with the `remote:' prefix, either via the `set sysroot' command or via
3556 the `--with-sysroot' configure-time option.
3558 * "info sharedlibrary" now takes an optional regex of libraries to show,
3559 and it now reports if a shared library has no debugging information.
3561 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3562 now complete on file names.
3564 * When completing in expressions, gdb will attempt to limit
3565 completions to allowable structure or union fields, where appropriate.
3566 For instance, consider:
3568 # struct example { int f1; double f2; };
3569 # struct example variable;
3572 If the user types TAB at the end of this command line, the available
3573 completions will be "f1" and "f2".
3575 * Inlined functions are now supported. They show up in backtraces, and
3576 the "step", "next", and "finish" commands handle them automatically.
3578 * GDB now supports the token-splicing (##) and stringification (#)
3579 operators when expanding macros. It also supports variable-arity
3582 * GDB now supports inspecting extra signal information, exported by
3583 the new $_siginfo convenience variable. The feature is currently
3584 implemented on linux ARM, i386 and amd64.
3586 * GDB can now display the VFP floating point registers and NEON vector
3587 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3588 can provide these registers (requires Linux 2.6.30 or later). Remote
3589 and simulator targets may also provide them.
3591 * New remote packets
3594 Search memory for a sequence of bytes.
3597 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3598 operation over reliable transport links. Use of this packet is
3599 controlled by the `set remote noack-packet' command.
3602 Kill the process with the specified process ID. Use this in preference
3603 to `k' when multiprocess protocol extensions are supported.
3606 Obtains additional operating system information
3610 Read or write additional signal information.
3612 * Removed remote protocol undocumented extension
3614 An undocumented extension to the remote protocol's `S' stop reply
3615 packet that permited the stub to pass a process id was removed.
3616 Remote servers should use the `T' stop reply packet instead.
3618 * GDB now supports multiple function calling conventions according to the
3619 DWARF-2 DW_AT_calling_convention function attribute.
3621 * The SH target utilizes the aforementioned change to distinguish between gcc
3622 and Renesas calling convention. It also adds the new CLI commands
3623 `set/show sh calling-convention'.
3625 * GDB can now read compressed debug sections, as produced by GNU gold
3626 with the --compress-debug-sections=zlib flag.
3628 * 64-bit core files are now supported on AIX.
3630 * Thread switching is now supported on Tru64.
3632 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3633 which will be allocated using malloc later in program execution.
3635 * The qXfer:libraries:read remote procotol packet now allows passing a
3636 list of section offsets.
3638 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3639 conditions handling signals delivered during attach or thread creation
3640 have also been fixed.
3642 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3643 From the user's standpoint, all unqualified instances of True and False
3644 are treated as the standard definitions, regardless of context.
3646 * GDB now parses C++ symbol and type names more flexibly. For
3649 template<typename T> class C { };
3652 GDB will now correctly handle all of:
3654 ptype C<char const *>
3655 ptype C<char const*>
3656 ptype C<const char *>
3657 ptype C<const char*>
3659 * New features in the GDB remote stub, gdbserver
3661 - The "--wrapper" command-line argument tells gdbserver to use a
3662 wrapper program to launch programs for debugging.
3664 - On PowerPC and S/390 targets, it is now possible to use a single
3665 gdbserver executable to debug both 32-bit and 64-bit programs.
3666 (This requires gdbserver itself to be built as a 64-bit executable.)
3668 - gdbserver uses the new noack protocol mode for TCP connections to
3669 reduce communications latency, if also supported and enabled in GDB.
3671 - Support for the sparc64-linux-gnu target is now included in
3674 - The amd64-linux build of gdbserver now supports debugging both
3675 32-bit and 64-bit programs.
3677 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3678 now support hardware watchpoints, and will use them automatically
3683 GDB now has support for scripting using Python. Whether this is
3684 available is determined at configure time.
3686 New GDB commands can now be written in Python.
3688 * Ada tasking support
3690 Ada tasks can now be inspected in GDB. The following commands have
3694 Print the list of Ada tasks.
3696 Print detailed information about task number N.
3698 Print the task number of the current task.
3700 Switch the context of debugging to task number N.
3702 * Support for user-defined prefixed commands. The "define" command can
3703 add new commands to existing prefixes, e.g. "target".
3705 * Multi-inferior, multi-process debugging.
3707 GDB now has generalized support for multi-inferior debugging. See
3708 "Debugging Multiple Inferiors" in the manual for more information.
3709 Although availability still depends on target support, the command
3710 set is more uniform now. The GNU/Linux specific multi-forks support
3711 has been migrated to this new framework. This implied some user
3712 visible changes; see "New commands" and also "Removed commands"
3715 * Target descriptions can now describe the target OS ABI. See the
3716 "Target Description Format" section in the user manual for more
3719 * Target descriptions can now describe "compatible" architectures
3720 to indicate that the target can execute applications for a different
3721 architecture in addition to those for the main target architecture.
3722 See the "Target Description Format" section in the user manual for
3725 * Multi-architecture debugging.
3727 GDB now includes general supports for debugging applications on
3728 hybrid systems that use more than one single processor architecture
3729 at the same time. Each such hybrid architecture still requires
3730 specific support to be added. The only hybrid architecture supported
3731 in this version of GDB is the Cell Broadband Engine.
3733 * GDB now supports integrated debugging of Cell/B.E. applications that
3734 use both the PPU and SPU architectures. To enable support for hybrid
3735 Cell/B.E. debugging, you need to configure GDB to support both the
3736 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3737 --enable-targets configure option.
3739 * Non-stop mode debugging.
3741 For some targets, GDB now supports an optional mode of operation in
3742 which you can examine stopped threads while other threads continue
3743 to execute freely. This is referred to as non-stop mode, with the
3744 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3745 section in the user manual for more information.
3747 To be able to support remote non-stop debugging, a remote stub needs
3748 to implement the non-stop mode remote protocol extensions, as
3749 described in the "Remote Non-Stop" section of the user manual. The
3750 GDB remote stub, gdbserver, has been adjusted to support these
3751 extensions on linux targets.
3753 * New commands (for set/show, see "New options" below)
3755 catch syscall [NAME(S) | NUMBER(S)]
3756 Catch system calls. Arguments, which should be names of system
3757 calls or their numbers, mean catch only those syscalls. Without
3758 arguments, every syscall will be caught. When the inferior issues
3759 any of the specified syscalls, GDB will stop and announce the system
3760 call, both when it is called and when its call returns. This
3761 feature is currently available with a native GDB running on the
3762 Linux Kernel, under the following architectures: x86, x86_64,
3763 PowerPC and PowerPC64.
3765 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3767 Search memory for a sequence of bytes.
3769 maint set python print-stack
3770 maint show python print-stack
3771 Show a stack trace when an error is encountered in a Python script.
3774 Invoke CODE by passing it to the Python interpreter.
3779 These allow macros to be defined, undefined, and listed
3783 Show operating system information about processes.
3786 List the inferiors currently under GDB's control.
3789 Switch focus to inferior number NUM.
3792 Detach from inferior number NUM.
3795 Kill inferior number NUM.
3799 set spu stop-on-load
3800 show spu stop-on-load
3801 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3803 set spu auto-flush-cache
3804 show spu auto-flush-cache
3805 Control whether to automatically flush the software-managed cache
3806 during Cell/B.E. debugging.
3808 set sh calling-convention
3809 show sh calling-convention
3810 Control the calling convention used when calling SH target functions.
3813 show debug timestamp
3814 Control display of timestamps with GDB debugging output.
3816 set disassemble-next-line
3817 show disassemble-next-line
3818 Control display of disassembled source lines or instructions when
3821 set remote noack-packet
3822 show remote noack-packet
3823 Set/show the use of remote protocol QStartNoAckMode packet. See above
3824 under "New remote packets."
3826 set remote query-attached-packet
3827 show remote query-attached-packet
3828 Control use of remote protocol `qAttached' (query-attached) packet.
3830 set remote read-siginfo-object
3831 show remote read-siginfo-object
3832 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3835 set remote write-siginfo-object
3836 show remote write-siginfo-object
3837 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3840 set remote reverse-continue
3841 show remote reverse-continue
3842 Control use of remote protocol 'bc' (reverse-continue) packet.
3844 set remote reverse-step
3845 show remote reverse-step
3846 Control use of remote protocol 'bs' (reverse-step) packet.
3848 set displaced-stepping
3849 show displaced-stepping
3850 Control displaced stepping mode. Displaced stepping is a way to
3851 single-step over breakpoints without removing them from the debuggee.
3852 Also known as "out-of-line single-stepping".
3855 show debug displaced
3856 Control display of debugging info for displaced stepping.
3858 maint set internal-error
3859 maint show internal-error
3860 Control what GDB does when an internal error is detected.
3862 maint set internal-warning
3863 maint show internal-warning
3864 Control what GDB does when an internal warning is detected.
3869 Use a wrapper program to launch programs for debugging.
3871 set multiple-symbols (all|ask|cancel)
3872 show multiple-symbols
3873 The value of this variable can be changed to adjust the debugger behavior
3874 when an expression or a breakpoint location contains an ambiguous symbol
3875 name (an overloaded function name, for instance).
3877 set breakpoint always-inserted
3878 show breakpoint always-inserted
3879 Keep breakpoints always inserted in the target, as opposed to inserting
3880 them when resuming the target, and removing them when the target stops.
3881 This option can improve debugger performance on slow remote targets.
3883 set arm fallback-mode (arm|thumb|auto)
3884 show arm fallback-mode
3885 set arm force-mode (arm|thumb|auto)
3887 These commands control how ARM GDB determines whether instructions
3888 are ARM or Thumb. The default for both settings is auto, which uses
3889 the current CPSR value for instructions without symbols; previous
3890 versions of GDB behaved as if "set arm fallback-mode arm".
3892 set disable-randomization
3893 show disable-randomization
3894 Standalone programs run with the virtual address space randomization enabled
3895 by default on some platforms. This option keeps the addresses stable across
3896 multiple debugging sessions.
3900 Control whether other threads are stopped or not when some thread hits
3905 Requests that asynchronous execution is enabled in the target, if available.
3906 In this case, it's possible to resume target in the background, and interact
3907 with GDB while the target is running. "show target-async" displays the
3908 current state of asynchronous execution of the target.
3910 set target-wide-charset
3911 show target-wide-charset
3912 The target-wide-charset is the name of the character set that GDB
3913 uses when printing characters whose type is wchar_t.
3915 set tcp auto-retry (on|off)
3917 set tcp connect-timeout
3918 show tcp connect-timeout
3919 These commands allow GDB to retry failed TCP connections to a remote stub
3920 with a specified timeout period; this is useful if the stub is launched
3921 in parallel with GDB but may not be ready to accept connections immediately.
3923 set libthread-db-search-path
3924 show libthread-db-search-path
3925 Control list of directories which GDB will search for appropriate
3928 set schedule-multiple (on|off)
3929 show schedule-multiple
3930 Allow GDB to resume all threads of all processes or only threads of
3931 the current process.
3935 Use more aggressive caching for accesses to the stack. This improves
3936 performance of remote debugging (particularly backtraces) without
3937 affecting correctness.
3939 set interactive-mode (on|off|auto)
3940 show interactive-mode
3941 Control whether GDB runs in interactive mode (on) or not (off).
3942 When in interactive mode, GDB waits for the user to answer all
3943 queries. Otherwise, GDB does not wait and assumes the default
3944 answer. When set to auto (the default), GDB determines which
3945 mode to use based on the stdin settings.
3950 For program forks, this is replaced by the new more generic `info
3951 inferiors' command. To list checkpoints, you can still use the
3952 `info checkpoints' command, which was an alias for the `info forks'
3956 Replaced by the new `inferior' command. To switch between
3957 checkpoints, you can still use the `restart' command, which was an
3958 alias for the `fork' command.
3961 This is removed, since some targets don't have a notion of
3962 processes. To switch between processes, you can still use the
3963 `inferior' command using GDB's own inferior number.
3966 For program forks, this is replaced by the new more generic `kill
3967 inferior' command. To delete a checkpoint, you can still use the
3968 `delete checkpoint' command, which was an alias for the `delete
3972 For program forks, this is replaced by the new more generic `detach
3973 inferior' command. To detach a checkpoint, you can still use the
3974 `detach checkpoint' command, which was an alias for the `detach
3977 * New native configurations
3979 x86/x86_64 Darwin i[34567]86-*-darwin*
3981 x86_64 MinGW x86_64-*-mingw*
3985 Lattice Mico32 lm32-*
3986 x86 DICOS i[34567]86-*-dicos*
3987 x86_64 DICOS x86_64-*-dicos*
3990 * The GDB remote stub, gdbserver, now supports x86 Windows CE
3991 (mingw32ce) debugging.
3997 These commands were actually not implemented on any target.
3999 *** Changes in GDB 6.8
4001 * New native configurations
4003 NetBSD/hppa hppa*-*netbsd*
4004 Xtensa GNU/Linux xtensa*-*-linux*
4008 NetBSD/hppa hppa*-*-netbsd*
4009 Xtensa GNU/Lunux xtensa*-*-linux*
4011 * Change in command line behavior -- corefiles vs. process ids.
4013 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4014 attaching to process NUMBER fails, GDB no longer attempts to open a
4015 core file named NUMBER. Attaching to a program using the -c option
4016 is no longer supported. Instead, use the '-p' or '--pid' options.
4018 * GDB can now be built as a native debugger for debugging Windows x86
4019 (mingw32) Portable Executable (PE) programs.
4021 * Pending breakpoints no longer change their number when their address
4024 * GDB now supports breakpoints with multiple locations,
4025 including breakpoints on C++ constructors, inside C++ templates,
4026 and in inlined functions.
4028 * GDB's ability to debug optimized code has been improved. GDB more
4029 accurately identifies function bodies and lexical blocks that occupy
4030 more than one contiguous range of addresses.
4032 * Target descriptions can now describe registers for PowerPC.
4034 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4035 registers on PowerPC targets.
4037 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4038 targets even when the libthread_db library is not available.
4040 * The GDB remote stub, gdbserver, now supports the new file transfer
4041 commands (remote put, remote get, and remote delete).
4043 * The GDB remote stub, gdbserver, now supports run and attach in
4044 extended-remote mode.
4046 * hppa*64*-*-hpux11* target broken
4047 The debugger is unable to start a program and fails with the following
4048 error: "Error trying to get information about dynamic linker".
4049 The gdb-6.7 release is also affected.
4051 * GDB now supports the --enable-targets= configure option to allow
4052 building a single GDB executable that supports multiple remote
4053 target architectures.
4055 * GDB now supports debugging C and C++ programs which use the
4056 Decimal Floating Point extension. In addition, the PowerPC target
4057 now has a set of pseudo-registers to inspect decimal float values
4058 stored in two consecutive float registers.
4060 * The -break-insert MI command can optionally create pending
4063 * Improved support for debugging Ada
4064 Many improvements to the Ada language support have been made. These
4066 - Better support for Ada2005 interface types
4067 - Improved handling of arrays and slices in general
4068 - Better support for Taft-amendment types
4069 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4071 - Improved command completion in Ada
4074 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4079 set print frame-arguments (all|scalars|none)
4080 show print frame-arguments
4081 The value of this variable can be changed to control which argument
4082 values should be printed by the debugger when displaying a frame.
4087 Transfer files to and from a remote target, and delete remote files.
4094 Transfer files to and from a remote target, and delete remote files.
4096 * New remote packets
4103 Open, close, read, write, and delete files on the remote system.
4106 Attach to an existing process on the remote system, in extended-remote
4110 Run a new process on the remote system, in extended-remote mode.
4112 *** Changes in GDB 6.7
4114 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4115 bfd, libiberty and opcodes, as revealed by static analysis donated by
4116 Coverity, Inc. (http://scan.coverity.com).
4118 * When looking up multiply-defined global symbols, GDB will now prefer the
4119 symbol definition in the current shared library if it was built using the
4120 -Bsymbolic linker option.
4122 * When the Text User Interface (TUI) is not configured, GDB will now
4123 recognize the -tui command-line option and print a message that the TUI
4126 * The GDB remote stub, gdbserver, now has lower overhead for high
4127 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4129 * GDB for MIPS targets now autodetects whether a remote target provides
4130 32-bit or 64-bit register values.
4132 * Support for C++ member pointers has been improved.
4134 * GDB now understands XML target descriptions, which specify the
4135 target's overall architecture. GDB can read a description from
4136 a local file or over the remote serial protocol.
4138 * Vectors of single-byte data use a new integer type which is not
4139 automatically displayed as character or string data.
4141 * The /s format now works with the print command. It displays
4142 arrays of single-byte integers and pointers to single-byte integers
4145 * Target descriptions can now describe target-specific registers,
4146 for architectures which have implemented the support (currently
4147 only ARM, M68K, and MIPS).
4149 * GDB and the GDB remote stub, gdbserver, now support the XScale
4152 * The GDB remote stub, gdbserver, has been updated to support
4153 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4154 has been rewritten to use the standard GDB remote protocol.
4156 * GDB can now step into C++ functions which are called through thunks.
4158 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4160 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4161 layout. It also supports a TextSeg= and DataSeg= response when only
4162 segment base addresses (rather than offsets) are available.
4164 * The /i format now outputs any trailing branch delay slot instructions
4165 immediately following the last instruction within the count specified.
4167 * The GDB remote protocol "T" stop reply packet now supports a
4168 "library" response. Combined with the new "qXfer:libraries:read"
4169 packet, this response allows GDB to debug shared libraries on targets
4170 where the operating system manages the list of loaded libraries (e.g.
4171 Windows and SymbianOS).
4173 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4174 (DLLs) on Windows and Windows CE targets.
4176 * GDB now supports a faster verification that a .debug file matches its binary
4177 according to its build-id signature, if the signature is present.
4183 Enable or disable hardware flow control (RTS/CTS) on the serial port
4184 when debugging using remote targets.
4186 set mem inaccessible-by-default
4187 show mem inaccessible-by-default
4188 If the target supplies a memory map, for instance via the remote
4189 protocol's "qXfer:memory-map:read" packet, setting this variable
4190 prevents GDB from accessing memory outside the memory map. This
4191 is useful for targets with memory mapped registers or which react
4192 badly to accesses of unmapped address space.
4194 set breakpoint auto-hw
4195 show breakpoint auto-hw
4196 If the target supplies a memory map, for instance via the remote
4197 protocol's "qXfer:memory-map:read" packet, setting this variable
4198 lets GDB use hardware breakpoints automatically for memory regions
4199 where it can not use software breakpoints. This covers both the
4200 "break" command and internal breakpoints used for other commands
4201 including "next" and "finish".
4204 catch exception unhandled
4205 Stop the program execution when Ada exceptions are raised.
4208 Stop the program execution when an Ada assertion failed.
4212 Set an alternate system root for target files. This is a more
4213 general version of "set solib-absolute-prefix", which is now
4214 an alias to "set sysroot".
4217 Provide extended SPU facility status information. This set of
4218 commands is available only when debugging the Cell/B.E. SPU
4221 * New native configurations
4223 OpenBSD/sh sh*-*openbsd*
4226 unset tdesc filename
4228 Use the specified local file as an XML target description, and do
4229 not query the target for its built-in description.
4233 OpenBSD/sh sh*-*-openbsd*
4234 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4235 Toshiba Media Processor mep-elf
4237 * New remote packets
4240 Ignore the specified signals; pass them directly to the debugged program
4241 without stopping other threads or reporting them to GDB.
4243 qXfer:features:read:
4244 Read an XML target description from the target, which describes its
4249 Read or write contents of an spufs file on the target system. These
4250 packets are available only on the Cell/B.E. SPU architecture.
4252 qXfer:libraries:read:
4253 Report the loaded shared libraries. Combined with new "T" packet
4254 response, this packet allows GDB to debug shared libraries on
4255 targets where the operating system manages the list of loaded
4256 libraries (e.g. Windows and SymbianOS).
4260 Support for these obsolete configurations has been removed.
4268 i[34567]86-*-lynxos*
4269 i[34567]86-*-netware*
4270 i[34567]86-*-sco3.2v5*
4271 i[34567]86-*-sco3.2v4*
4273 i[34567]86-*-sysv4.2*
4276 i[34567]86-*-unixware2*
4277 i[34567]86-*-unixware*
4286 * Other removed features
4293 Various m68k-only ROM monitors.
4300 Various Renesas ROM monitors and debugging interfaces for SH and
4305 Support for a Macraigor serial interface to on-chip debugging.
4306 GDB does not directly support the newer parallel or USB
4311 A debug information format. The predecessor to DWARF 2 and
4312 DWARF 3, which are still supported.
4314 Support for the HP aCC compiler on HP-UX/PA-RISC
4316 SOM-encapsulated symbolic debugging information, automatic
4317 invocation of pxdb, and the aCC custom C++ ABI. This does not
4318 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4319 with aCC can still be debugged on an assembly level.
4321 MIPS ".pdr" sections
4323 A MIPS-specific format used to describe stack frame layout
4324 in debugging information.
4328 GDB could work with an older version of Guile to debug
4329 the interpreter and Scheme programs running in it.
4331 set mips stack-arg-size
4332 set mips saved-gpreg-size
4334 Use "set mips abi" to control parameter passing for MIPS.
4336 *** Changes in GDB 6.6
4341 Cell Broadband Engine SPU spu-elf
4343 * GDB can now be configured as a cross-debugger targeting native Windows
4344 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4345 running on a Windows system over TCP/IP to debug Windows programs.
4347 * The GDB remote stub, gdbserver, has been updated to support Windows and
4348 Cygwin debugging. Both single-threaded and multi-threaded programs are
4351 * The "set trust-readonly-sections" command works again. This command was
4352 broken in GDB 6.3, 6.4, and 6.5.
4354 * The "load" command now supports writing to flash memory, if the remote
4355 stub provides the required support.
4357 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4358 longer requires symbolic debug information (e.g. DWARF-2).
4363 unset substitute-path
4364 show substitute-path
4365 Manage a list of substitution rules that GDB uses to rewrite the name
4366 of the directories where the sources are located. This can be useful
4367 for instance when the sources were moved to a different location
4368 between compilation and debugging.
4372 Print each CLI command as it is executed. Each command is prefixed with
4373 a number of `+' symbols representing the nesting depth.
4374 The source command now has a `-v' option to enable the same feature.
4378 The ARM Demon monitor support (RDP protocol, "target rdp").
4380 Kernel Object Display, an embedded debugging feature which only worked with
4381 an obsolete version of Cisco IOS.
4383 The 'set download-write-size' and 'show download-write-size' commands.
4385 * New remote packets
4388 Tell a stub about GDB client features, and request remote target features.
4389 The first feature implemented is PacketSize, which allows the target to
4390 specify the size of packets it can handle - to minimize the number of
4391 packets required and improve performance when connected to a remote
4395 Fetch an OS auxilliary vector from the remote stub. This packet is a
4396 more efficient replacement for qPart:auxv:read.
4398 qXfer:memory-map:read:
4399 Fetch a memory map from the remote stub, including information about
4400 RAM, ROM, and flash memory devices.
4405 Erase and program a flash memory device.
4407 * Removed remote packets
4410 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4411 used it, and only gdbserver implemented it.
4413 *** Changes in GDB 6.5
4417 Renesas M32C/M16C m32c-elf
4419 Morpho Technologies ms1 ms1-elf
4423 init-if-undefined Initialize a convenience variable, but
4424 only if it doesn't already have a value.
4426 The following commands are presently only implemented for native GNU/Linux:
4428 checkpoint Save a snapshot of the program state.
4430 restart <n> Return the program state to a
4431 previously saved state.
4433 info checkpoints List currently saved checkpoints.
4435 delete-checkpoint <n> Delete a previously saved checkpoint.
4437 set|show detach-on-fork Tell gdb whether to detach from a newly
4438 forked process, or to keep debugging it.
4440 info forks List forks of the user program that
4441 are available to be debugged.
4443 fork <n> Switch to debugging one of several
4444 forks of the user program that are
4445 available to be debugged.
4447 delete-fork <n> Delete a fork from the list of forks
4448 that are available to be debugged (and
4449 kill the forked process).
4451 detach-fork <n> Delete a fork from the list of forks
4452 that are available to be debugged (and
4453 allow the process to continue).
4457 Morpho Technologies ms2 ms1-elf
4459 * Improved Windows host support
4461 GDB now builds as a cross debugger hosted on i686-mingw32, including
4462 native console support, and remote communications using either
4463 network sockets or serial ports.
4465 * Improved Modula-2 language support
4467 GDB can now print most types in the Modula-2 syntax. This includes:
4468 basic types, set types, record types, enumerated types, range types,
4469 pointer types and ARRAY types. Procedure var parameters are correctly
4470 printed and hexadecimal addresses and character constants are also
4471 written in the Modula-2 syntax. Best results can be obtained by using
4472 GNU Modula-2 together with the -gdwarf-2 command line option.
4476 The ARM rdi-share module.
4478 The Netware NLM debug server.
4480 *** Changes in GDB 6.4
4482 * New native configurations
4484 OpenBSD/arm arm*-*-openbsd*
4485 OpenBSD/mips64 mips64-*-openbsd*
4489 Morpho Technologies ms1 ms1-elf
4491 * New command line options
4493 --batch-silent As for --batch, but totally silent.
4494 --return-child-result The debugger will exist with the same value
4495 the child (debugged) program exited with.
4496 --eval-command COMMAND, -ex COMMAND
4497 Execute a single GDB CLI command. This may be
4498 specified multiple times and in conjunction
4499 with the --command (-x) option.
4501 * Deprecated commands removed
4503 The following commands, that were deprecated in 2000, have been
4507 set|show arm disassembly-flavor set|show arm disassembler
4508 othernames set arm disassembler
4509 set|show remotedebug set|show debug remote
4510 set|show archdebug set|show debug arch
4511 set|show eventdebug set|show debug event
4514 * New BSD user-level threads support
4516 It is now possible to debug programs using the user-level threads
4517 library on OpenBSD and FreeBSD. Currently supported (target)
4520 FreeBSD/amd64 x86_64-*-freebsd*
4521 FreeBSD/i386 i386-*-freebsd*
4522 OpenBSD/i386 i386-*-openbsd*
4524 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4525 are not yet supported.
4527 * New support for Matsushita MN10300 w/sim added
4528 (Work in progress). mn10300-elf.
4530 * REMOVED configurations and files
4532 VxWorks and the XDR protocol *-*-vxworks
4533 Motorola MCORE mcore-*-*
4534 National Semiconductor NS32000 ns32k-*-*
4536 * New "set print array-indexes" command
4538 After turning this setting "on", GDB prints the index of each element
4539 when displaying arrays. The default is "off" to preserve the previous
4542 * VAX floating point support
4544 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4546 * User-defined command support
4548 In addition to using $arg0..$arg9 for argument passing, it is now possible
4549 to use $argc to determine now many arguments have been passed. See the
4550 section on user-defined commands in the user manual for more information.
4552 *** Changes in GDB 6.3:
4554 * New command line option
4556 GDB now accepts -l followed by a number to set the timeout for remote
4559 * GDB works with GCC -feliminate-dwarf2-dups
4561 GDB now supports a more compact representation of DWARF-2 debug
4562 information using DW_FORM_ref_addr references. These are produced
4563 by GCC with the option -feliminate-dwarf2-dups and also by some
4564 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4565 to use -feliminate-dwarf2-dups.
4567 * Internationalization
4569 When supported by the host system, GDB will be built with
4570 internationalization (libintl). The task of marking up the sources is
4571 continued, we're looking forward to our first translation.
4575 Initial support for debugging programs compiled with the GNAT
4576 implementation of the Ada programming language has been integrated
4577 into GDB. In this release, support is limited to expression evaluation.
4579 * New native configurations
4581 GNU/Linux/m32r m32r-*-linux-gnu
4585 GDB's remote protocol now includes support for the 'p' packet. This
4586 packet is used to fetch individual registers from a remote inferior.
4588 * END-OF-LIFE registers[] compatibility module
4590 GDB's internal register infrastructure has been completely rewritten.
4591 The new infrastructure making possible the implementation of key new
4592 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4595 GDB 6.3 will be the last release to include the the registers[]
4596 compatibility module that allowed out-of-date configurations to
4597 continue to work. This change directly impacts the following
4607 powerpc bdm protocol
4609 Unless there is activity to revive these configurations, they will be
4610 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4612 * OBSOLETE configurations and files
4614 Configurations that have been declared obsolete in this release have
4615 been commented out. Unless there is activity to revive these
4616 configurations, the next release of GDB will have their sources
4617 permanently REMOVED.
4626 *** Changes in GDB 6.2.1:
4628 * MIPS `break main; run' gave an heuristic-fence-post warning
4630 When attempting to run even a simple program, a warning about
4631 heuristic-fence-post being hit would be reported. This problem has
4634 * MIPS IRIX 'long double' crashed GDB
4636 When examining a long double variable, GDB would get a segmentation
4637 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4638 IRIX long double values).
4642 A bug in the VAX stack code was causing problems with the "next"
4643 command. This problem has been fixed.
4645 *** Changes in GDB 6.2:
4647 * Fix for ``many threads''
4649 On GNU/Linux systems that use the NPTL threads library, a program
4650 rapidly creating and deleting threads would confuse GDB leading to the
4653 ptrace: No such process.
4654 thread_db_get_info: cannot get thread info: generic error
4656 This problem has been fixed.
4658 * "-async" and "-noasync" options removed.
4660 Support for the broken "-noasync" option has been removed (it caused
4663 * New ``start'' command.
4665 This command runs the program until the begining of the main procedure.
4667 * New BSD Kernel Data Access Library (libkvm) interface
4669 Using ``target kvm'' it is now possible to debug kernel core dumps and
4670 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4671 platforms. Currently supported (native-only) configurations are:
4673 FreeBSD/amd64 x86_64-*-freebsd*
4674 FreeBSD/i386 i?86-*-freebsd*
4675 NetBSD/i386 i?86-*-netbsd*
4676 NetBSD/m68k m68*-*-netbsd*
4677 NetBSD/sparc sparc-*-netbsd*
4678 OpenBSD/amd64 x86_64-*-openbsd*
4679 OpenBSD/i386 i?86-*-openbsd*
4680 OpenBSD/m68k m68*-openbsd*
4681 OpenBSD/sparc sparc-*-openbsd*
4683 * Signal trampoline code overhauled
4685 Many generic problems with GDB's signal handling code have been fixed.
4686 These include: backtraces through non-contiguous stacks; recognition
4687 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4688 call; backtrace through a signal trampoline; step into and out of
4689 signal handlers; and single-stepping in the signal trampoline.
4691 Please note that kernel bugs are a limiting factor here. These
4692 features have been shown to work on an s390 GNU/Linux system that
4693 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4695 * Cygwin support for DWARF 2 added.
4697 * New native configurations
4699 GNU/Linux/hppa hppa*-*-linux*
4700 OpenBSD/hppa hppa*-*-openbsd*
4701 OpenBSD/m68k m68*-*-openbsd*
4702 OpenBSD/m88k m88*-*-openbsd*
4703 OpenBSD/powerpc powerpc-*-openbsd*
4704 NetBSD/vax vax-*-netbsd*
4705 OpenBSD/vax vax-*-openbsd*
4707 * END-OF-LIFE frame compatibility module
4709 GDB's internal frame infrastructure has been completely rewritten.
4710 The new infrastructure making it possible to support key new features
4711 including DWARF 2 Call Frame Information. To aid in the task of
4712 migrating old configurations to this new infrastructure, a
4713 compatibility module, that allowed old configurations to continue to
4714 work, was also included.
4716 GDB 6.2 will be the last release to include this frame compatibility
4717 module. This change directly impacts the following configurations:
4727 Unless there is activity to revive these configurations, they will be
4728 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4730 * REMOVED configurations and files
4732 Sun 3, running SunOS 3 m68*-*-sunos3*
4733 Sun 3, running SunOS 4 m68*-*-sunos4*
4734 Sun 2, running SunOS 3 m68000-*-sunos3*
4735 Sun 2, running SunOS 4 m68000-*-sunos4*
4736 Motorola 680x0 running LynxOS m68*-*-lynxos*
4737 AT&T 3b1/Unix pc m68*-att-*
4738 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4739 decstation mips-dec-* mips-little-*
4740 riscos mips-*-riscos* mips-*-sysv*
4741 sonymips mips-sony-*
4742 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4744 *** Changes in GDB 6.1.1:
4746 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4748 The TUI (Text-mode User Interface) is now built as part of a default
4749 GDB configuration. It is enabled by either selecting the TUI with the
4750 command line option "-i=tui" or by running the separate "gdbtui"
4751 program. For more information on the TUI, see the manual "Debugging
4754 * Pending breakpoint support (also included in GDB 6.1)
4756 Support has been added to allow you to specify breakpoints in shared
4757 libraries that have not yet been loaded. If a breakpoint location
4758 cannot be found, and the "breakpoint pending" option is set to auto,
4759 GDB queries you if you wish to make the breakpoint pending on a future
4760 shared-library load. If and when GDB resolves the breakpoint symbol,
4761 the pending breakpoint is removed as one or more regular breakpoints
4764 Pending breakpoints are very useful for GCJ Java debugging.
4766 * Fixed ISO-C build problems
4768 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4769 non ISO-C code that stopped them being built using a more strict ISO-C
4770 compiler (e.g., IBM's C compiler).
4772 * Fixed build problem on IRIX 5
4774 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4775 wasn't able to compile compile on an IRIX 5 system.
4777 * Added execute permission to gdb/gdbserver/configure
4779 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4780 permission. This bug would cause configure to fail on a number of
4781 systems (Solaris, IRIX). Ref: server/519.
4783 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4785 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4786 has been updated to use constant array sizes.
4788 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4790 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4791 its generated DWARF Call Frame Info. This encoding was causing GDB to
4792 panic, that panic has been fixed. Ref: gdb/1628.
4794 * Fixed a problem when examining parameters in shared library code.
4796 When examining parameters in optimized shared library code generated
4797 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4798 not available''. GDB now correctly displays the variable's value.
4800 *** Changes in GDB 6.1:
4802 * Removed --with-mmalloc
4804 Support for the mmalloc memory manager has been removed, as it
4805 conflicted with the internal gdb byte cache.
4807 * Changes in AMD64 configurations
4809 The AMD64 target now includes the %cs and %ss registers. As a result
4810 the AMD64 remote protocol has changed; this affects the floating-point
4811 and SSE registers. If you rely on those registers for your debugging,
4812 you should upgrade gdbserver on the remote side.
4814 * Revised SPARC target
4816 The SPARC target has been completely revised, incorporating the
4817 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4818 support for LynxOS and SunOS 4 has been dropped. Calling functions
4819 from within GDB on operating systems with a non-executable stack
4820 (Solaris, OpenBSD) now works.
4824 GDB has a new C++ demangler which does a better job on the mangled
4825 names generated by current versions of g++. It also runs faster, so
4826 with this and other changes gdb should now start faster on large C++
4829 * DWARF 2 Location Expressions
4831 GDB support for location expressions has been extended to support function
4832 arguments and frame bases. Older versions of GDB could crash when they
4835 * C++ nested types and namespaces
4837 GDB's support for nested types and namespaces in C++ has been
4838 improved, especially if you use the DWARF 2 debugging format. (This
4839 is the default for recent versions of GCC on most platforms.)
4840 Specifically, if you have a class "Inner" defined within a class or
4841 namespace "Outer", then GDB realizes that the class's name is
4842 "Outer::Inner", not simply "Inner". This should greatly reduce the
4843 frequency of complaints about not finding RTTI symbols. In addition,
4844 if you are stopped at inside of a function defined within a namespace,
4845 GDB modifies its name lookup accordingly.
4847 * New native configurations
4849 NetBSD/amd64 x86_64-*-netbsd*
4850 OpenBSD/amd64 x86_64-*-openbsd*
4851 OpenBSD/alpha alpha*-*-openbsd*
4852 OpenBSD/sparc sparc-*-openbsd*
4853 OpenBSD/sparc64 sparc64-*-openbsd*
4855 * New debugging protocols
4857 M32R with SDI protocol m32r-*-elf*
4859 * "set prompt-escape-char" command deleted.
4861 The command "set prompt-escape-char" has been deleted. This command,
4862 and its very obscure effet on GDB's prompt, was never documented,
4863 tested, nor mentioned in the NEWS file.
4865 * OBSOLETE configurations and files
4867 Configurations that have been declared obsolete in this release have
4868 been commented out. Unless there is activity to revive these
4869 configurations, the next release of GDB will have their sources
4870 permanently REMOVED.
4872 Sun 3, running SunOS 3 m68*-*-sunos3*
4873 Sun 3, running SunOS 4 m68*-*-sunos4*
4874 Sun 2, running SunOS 3 m68000-*-sunos3*
4875 Sun 2, running SunOS 4 m68000-*-sunos4*
4876 Motorola 680x0 running LynxOS m68*-*-lynxos*
4877 AT&T 3b1/Unix pc m68*-att-*
4878 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4879 decstation mips-dec-* mips-little-*
4880 riscos mips-*-riscos* mips-*-sysv*
4881 sonymips mips-sony-*
4882 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4884 * REMOVED configurations and files
4886 SGI Irix-4.x mips-sgi-irix4 or iris4
4887 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4888 Z8000 simulator z8k-zilog-none or z8ksim
4889 Matsushita MN10200 w/simulator mn10200-*-*
4890 H8/500 simulator h8500-hitachi-hms or h8500hms
4891 HP/PA running BSD hppa*-*-bsd*
4892 HP/PA running OSF/1 hppa*-*-osf*
4893 HP/PA Pro target hppa*-*-pro*
4894 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4895 386BSD i[3456]86-*-bsd*
4896 Sequent family i[3456]86-sequent-sysv4*
4897 i[3456]86-sequent-sysv*
4898 i[3456]86-sequent-bsd*
4899 SPARC running LynxOS sparc-*-lynxos*
4900 SPARC running SunOS 4 sparc-*-sunos4*
4901 Tsqware Sparclet sparclet-*-*
4902 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4904 *** Changes in GDB 6.0:
4908 Support for debugging the Objective-C programming language has been
4909 integrated into GDB.
4911 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4913 DWARF 2's Call Frame Information makes available compiler generated
4914 information that more exactly describes the program's run-time stack.
4915 By using this information, GDB is able to provide more robust stack
4918 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4919 have been updated to use a new backtrace mechanism which includes
4920 DWARF 2 CFI support.
4924 GDB's remote protocol has been extended to include support for hosted
4925 file I/O (where the remote target uses GDB's file system). See GDB's
4926 remote protocol documentation for details.
4928 * All targets using the new architecture framework.
4930 All of GDB's targets have been updated to use the new internal
4931 architecture framework. The way is now open for future GDB releases
4932 to include cross-architecture native debugging support (i386 on amd64,
4935 * GNU/Linux's Thread Local Storage (TLS)
4937 GDB now includes support for for the GNU/Linux implementation of
4938 per-thread variables.
4940 * GNU/Linux's Native POSIX Thread Library (NPTL)
4942 GDB's thread code has been updated to work with either the new
4943 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4945 * Separate debug info.
4947 GDB, in conjunction with BINUTILS, now supports a mechanism for
4948 automatically loading debug information from a separate file. Instead
4949 of shipping full debug and non-debug versions of system libraries,
4950 system integrators can now instead ship just the stripped libraries
4951 and optional debug files.
4953 * DWARF 2 Location Expressions
4955 DWARF 2 Location Expressions allow the compiler to more completely
4956 describe the location of variables (even in optimized code) to the
4959 GDB now includes preliminary support for location expressions (support
4960 for DW_OP_piece is still missing).
4964 A number of long standing bugs that caused GDB to die while starting a
4965 Java application have been fixed. GDB's Java support is now
4966 considered "useable".
4968 * GNU/Linux support for fork, vfork, and exec.
4970 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
4971 commands are now implemented for GNU/Linux. They require a 2.5.x or later
4974 * GDB supports logging output to a file
4976 There are two new commands, "set logging" and "show logging", which can be
4977 used to capture GDB's output to a file.
4979 * The meaning of "detach" has changed for gdbserver
4981 The "detach" command will now resume the application, as documented. To
4982 disconnect from gdbserver and leave it stopped, use the new "disconnect"
4985 * d10v, m68hc11 `regs' command deprecated
4987 The `info registers' command has been updated so that it displays the
4988 registers using a format identical to the old `regs' command.
4992 A new command, "maint set profile on/off", has been added. This command can
4993 be used to enable or disable profiling while running GDB, to profile a
4994 session or a set of commands. In addition there is a new configure switch,
4995 "--enable-profiling", which will cause GDB to be compiled with profiling
4996 data, for more informative profiling results.
4998 * Default MI syntax changed to "mi2".
5000 The default MI (machine interface) syntax, enabled by the command line
5001 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5002 "mi1", can be enabled by specifying the option "-i=mi1".
5004 Support for the original "mi0" syntax (included in GDB 5.0) has been
5007 Fix for gdb/192: removed extraneous space when displaying frame level.
5008 Fix for gdb/672: update changelist is now output in mi list format.
5009 Fix for gdb/702: a -var-assign that updates the value now shows up
5010 in a subsequent -var-update.
5012 * New native configurations.
5014 FreeBSD/amd64 x86_64-*-freebsd*
5016 * Multi-arched targets.
5018 HP/PA HPUX11 hppa*-*-hpux*
5019 Renesas M32R/D w/simulator m32r-*-elf*
5021 * OBSOLETE configurations and files
5023 Configurations that have been declared obsolete in this release have
5024 been commented out. Unless there is activity to revive these
5025 configurations, the next release of GDB will have their sources
5026 permanently REMOVED.
5028 Z8000 simulator z8k-zilog-none or z8ksim
5029 Matsushita MN10200 w/simulator mn10200-*-*
5030 H8/500 simulator h8500-hitachi-hms or h8500hms
5031 HP/PA running BSD hppa*-*-bsd*
5032 HP/PA running OSF/1 hppa*-*-osf*
5033 HP/PA Pro target hppa*-*-pro*
5034 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5035 Sequent family i[3456]86-sequent-sysv4*
5036 i[3456]86-sequent-sysv*
5037 i[3456]86-sequent-bsd*
5038 Tsqware Sparclet sparclet-*-*
5039 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5041 * REMOVED configurations and files
5044 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5045 IBM AIX PS/2 i[3456]86-*-aix
5046 i386 running Mach 3.0 i[3456]86-*-mach3*
5047 i386 running Mach i[3456]86-*-mach*
5048 i386 running OSF/1 i[3456]86-*osf1mk*
5049 HP/Apollo 68k Family m68*-apollo*-sysv*,
5051 m68*-hp-bsd*, m68*-hp-hpux*
5052 Argonaut Risc Chip (ARC) arc-*-*
5053 Mitsubishi D30V d30v-*-*
5054 Fujitsu FR30 fr30-*-elf*
5055 OS/9000 i[34]86-*-os9k
5056 I960 with MON960 i960-*-coff
5058 * MIPS $fp behavior changed
5060 The convenience variable $fp, for the MIPS, now consistently returns
5061 the address of the current frame's base. Previously, depending on the
5062 context, $fp could refer to either $sp or the current frame's base
5063 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5064 The GNU Source-Level Debugger''.
5066 *** Changes in GDB 5.3:
5068 * GNU/Linux shared library multi-threaded performance improved.
5070 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5071 `/proc', in preference to `ptrace' for memory reads. This may result
5072 in an improvement in the start-up time of multi-threaded, shared
5073 library applications when run under GDB. One GDB user writes: ``loads
5074 shared libs like mad''.
5076 * ``gdbserver'' now supports multi-threaded applications on some targets
5078 Support for debugging multi-threaded applications which use
5079 the GNU/Linux LinuxThreads package has been added for
5080 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5081 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5083 * GDB now supports C/C++ preprocessor macros.
5085 GDB now expands preprocessor macro invocations in C/C++ expressions,
5086 and provides various commands for showing macro definitions and how
5089 The new command `macro expand EXPRESSION' expands any macro
5090 invocations in expression, and shows the result.
5092 The new command `show macro MACRO-NAME' shows the definition of the
5093 macro named MACRO-NAME, and where it was defined.
5095 Most compilers don't include information about macros in the debugging
5096 information by default. In GCC 3.1, for example, you need to compile
5097 your program with the options `-gdwarf-2 -g3'. If the macro
5098 information is present in the executable, GDB will read it.
5100 * Multi-arched targets.
5102 DEC Alpha (partial) alpha*-*-*
5103 DEC VAX (partial) vax-*-*
5105 National Semiconductor NS32000 (partial) ns32k-*-*
5106 Motorola 68000 (partial) m68k-*-*
5107 Motorola MCORE mcore-*-*
5111 Fujitsu FRV architecture added by Red Hat frv*-*-*
5114 * New native configurations
5116 Alpha NetBSD alpha*-*-netbsd*
5117 SH NetBSD sh*-*-netbsdelf*
5118 MIPS NetBSD mips*-*-netbsd*
5119 UltraSPARC NetBSD sparc64-*-netbsd*
5121 * OBSOLETE configurations and files
5123 Configurations that have been declared obsolete in this release have
5124 been commented out. Unless there is activity to revive these
5125 configurations, the next release of GDB will have their sources
5126 permanently REMOVED.
5128 Mitsubishi D30V d30v-*-*
5129 OS/9000 i[34]86-*-os9k
5130 IBM AIX PS/2 i[3456]86-*-aix
5131 Fujitsu FR30 fr30-*-elf*
5132 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5133 Argonaut Risc Chip (ARC) arc-*-*
5134 i386 running Mach 3.0 i[3456]86-*-mach3*
5135 i386 running Mach i[3456]86-*-mach*
5136 i386 running OSF/1 i[3456]86-*osf1mk*
5137 HP/Apollo 68k Family m68*-apollo*-sysv*,
5139 m68*-hp-bsd*, m68*-hp-hpux*
5140 I960 with MON960 i960-*-coff
5142 * OBSOLETE languages
5144 CHILL, a Pascal like language used by telecommunications companies.
5146 * REMOVED configurations and files
5148 AMD 29k family via UDI a29k-amd-udi, udi29k
5149 A29K VxWorks a29k-*-vxworks
5150 AMD 29000 embedded, using EBMON a29k-none-none
5151 AMD 29000 embedded with COFF a29k-none-coff
5152 AMD 29000 embedded with a.out a29k-none-aout
5154 testsuite/gdb.hp/gdb.threads-hp/ directory
5156 * New command "set max-user-call-depth <nnn>"
5158 This command allows the user to limit the call depth of user-defined
5159 commands. The default is 1024.
5161 * Changes in FreeBSD/i386 native debugging.
5163 Support for the "generate-core-file" has been added.
5165 * New commands "dump", "append", and "restore".
5167 These commands allow data to be copied from target memory
5168 to a bfd-format or binary file (dump and append), and back
5169 from a file into memory (restore).
5171 * Improved "next/step" support on multi-processor Alpha Tru64.
5173 The previous single-step mechanism could cause unpredictable problems,
5174 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5175 of a software single-step mechanism prevents this.
5177 *** Changes in GDB 5.2.1:
5185 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5186 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5187 Fix, by Joel Brobecker imported from mainline.
5189 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5190 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5191 Fix, by Fred Fish, imported from mainline.
5193 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5194 Surprisingly enough, it works now.
5195 By Michal Ludvig, imported from mainline.
5197 i386 hardware watchpoint support:
5198 avoid misses on second run for some targets.
5199 By Pierre Muller, imported from mainline.
5201 *** Changes in GDB 5.2:
5203 * New command "set trust-readonly-sections on[off]".
5205 This command is a hint that tells gdb that read-only sections
5206 really are read-only (ie. that their contents will not change).
5207 In this mode, gdb will go to the object file rather than the
5208 target to read memory from read-only sections (such as ".text").
5209 This can be a significant performance improvement on some
5210 (notably embedded) targets.
5212 * New command "generate-core-file" (or "gcore").
5214 This new gdb command allows the user to drop a core file of the child
5215 process state at any time. So far it's been implemented only for
5216 GNU/Linux and Solaris, but should be relatively easily ported to other
5217 hosts. Argument is core file name (defaults to core.<pid>).
5219 * New command line option
5221 GDB now accepts --pid or -p followed by a process id.
5223 * Change in command line behavior -- corefiles vs. process ids.
5225 There is a subtle behavior in the way in which GDB handles
5226 command line arguments. The first non-flag argument is always
5227 a program to debug, but the second non-flag argument may either
5228 be a corefile or a process id. Previously, GDB would attempt to
5229 open the second argument as a corefile, and if that failed, would
5230 issue a superfluous error message and then attempt to attach it as
5231 a process. Now, if the second argument begins with a non-digit,
5232 it will be treated as a corefile. If it begins with a digit,
5233 GDB will attempt to attach it as a process, and if no such process
5234 is found, will then attempt to open it as a corefile.
5236 * Changes in ARM configurations.
5238 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5239 configuration is fully multi-arch.
5241 * New native configurations
5243 ARM NetBSD arm*-*-netbsd*
5244 x86 OpenBSD i[3456]86-*-openbsd*
5245 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5246 Sparc64 running FreeBSD sparc64-*-freebsd*
5250 Sanyo XStormy16 xstormy16-elf
5252 * OBSOLETE configurations and files
5254 Configurations that have been declared obsolete in this release have
5255 been commented out. Unless there is activity to revive these
5256 configurations, the next release of GDB will have their sources
5257 permanently REMOVED.
5259 AMD 29k family via UDI a29k-amd-udi, udi29k
5260 A29K VxWorks a29k-*-vxworks
5261 AMD 29000 embedded, using EBMON a29k-none-none
5262 AMD 29000 embedded with COFF a29k-none-coff
5263 AMD 29000 embedded with a.out a29k-none-aout
5265 testsuite/gdb.hp/gdb.threads-hp/ directory
5267 * REMOVED configurations and files
5269 TI TMS320C80 tic80-*-*
5271 PowerPC Solaris powerpcle-*-solaris*
5272 PowerPC Windows NT powerpcle-*-cygwin32
5273 PowerPC Netware powerpc-*-netware*
5274 Harris/CXUX m88k m88*-harris-cxux*
5275 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5276 ns32k-utek-sysv* ns32k-utek-*
5277 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5278 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5279 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5280 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5281 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5283 * Changes to command line processing
5285 The new `--args' feature can be used to specify command-line arguments
5286 for the inferior from gdb's command line.
5288 * Changes to key bindings
5290 There is a new `operate-and-get-next' function bound to `C-o'.
5292 *** Changes in GDB 5.1.1
5294 Fix compile problem on DJGPP.
5296 Fix a problem with floating-point registers on the i386 being
5299 Fix to stop GDB crashing on .debug_str debug info.
5301 Numerous documentation fixes.
5303 Numerous testsuite fixes.
5305 *** Changes in GDB 5.1:
5307 * New native configurations
5309 Alpha FreeBSD alpha*-*-freebsd*
5310 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5311 MIPS GNU/Linux mips*-*-linux*
5312 MIPS SGI Irix 6.x mips*-sgi-irix6*
5313 ia64 AIX ia64-*-aix*
5314 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5318 Motorola 68HC11 and 68HC12 m68hc11-elf
5320 UltraSparc running GNU/Linux sparc64-*-linux*
5322 * OBSOLETE configurations and files
5324 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5325 Harris/CXUX m88k m88*-harris-cxux*
5326 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5327 ns32k-utek-sysv* ns32k-utek-*
5328 TI TMS320C80 tic80-*-*
5330 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5331 PowerPC Solaris powerpcle-*-solaris*
5332 PowerPC Windows NT powerpcle-*-cygwin32
5333 PowerPC Netware powerpc-*-netware*
5334 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5335 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5336 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5337 Apple Macintosh (MPW) host N/A
5339 stuff.c (Program to stuff files into a specially prepared space in kdb)
5340 kdb-start.c (Main loop for the standalone kernel debugger)
5342 Configurations that have been declared obsolete in this release have
5343 been commented out. Unless there is activity to revive these
5344 configurations, the next release of GDB will have their sources
5345 permanently REMOVED.
5347 * REMOVED configurations and files
5349 Altos 3068 m68*-altos-*
5350 Convex c1-*-*, c2-*-*
5352 ARM RISCix arm-*-* (as host)
5356 * GDB has been converted to ISO C.
5358 GDB's source code has been converted to ISO C. In particular, the
5359 sources are fully protoized, and rely on standard headers being
5364 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5366 * The MI enabled by default.
5368 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5369 revised and enabled by default. Packages which use GDB as a debugging
5370 engine behind a UI or another front end are encouraged to switch to
5371 using the GDB/MI interface, instead of the old annotations interface
5372 which is now deprecated.
5374 * Support for debugging Pascal programs.
5376 GDB now includes support for debugging Pascal programs. The following
5377 main features are supported:
5379 - Pascal-specific data types such as sets;
5381 - automatic recognition of Pascal sources based on file-name
5384 - Pascal-style display of data types, variables, and functions;
5386 - a Pascal expression parser.
5388 However, some important features are not yet supported.
5390 - Pascal string operations are not supported at all;
5392 - there are some problems with boolean types;
5394 - Pascal type hexadecimal constants are not supported
5395 because they conflict with the internal variables format;
5397 - support for Pascal objects and classes is not full yet;
5399 - unlike Pascal, GDB is case-sensitive for symbol names.
5401 * Changes in completion.
5403 Commands such as `shell', `run' and `set args', which pass arguments
5404 to inferior programs, now complete on file names, similar to what
5405 users expect at the shell prompt.
5407 Commands which accept locations, such as `disassemble', `print',
5408 `breakpoint', `until', etc. now complete on filenames as well as
5409 program symbols. Thus, if you type "break foob TAB", and the source
5410 files linked into the programs include `foobar.c', that file name will
5411 be one of the candidates for completion. However, file names are not
5412 considered for completion after you typed a colon that delimits a file
5413 name from a name of a function in that file, as in "break foo.c:bar".
5415 `set demangle-style' completes on available demangling styles.
5417 * New platform-independent commands:
5419 It is now possible to define a post-hook for a command as well as a
5420 hook that runs before the command. For more details, see the
5421 documentation of `hookpost' in the GDB manual.
5423 * Changes in GNU/Linux native debugging.
5425 Support for debugging multi-threaded programs has been completely
5426 revised for all platforms except m68k and sparc. You can now debug as
5427 many threads as your system allows you to have.
5429 Attach/detach is supported for multi-threaded programs.
5431 Support for SSE registers was added for x86. This doesn't work for
5432 multi-threaded programs though.
5434 * Changes in MIPS configurations.
5436 Multi-arch support is enabled for all MIPS configurations.
5438 GDB can now be built as native debugger on SGI Irix 6.x systems for
5439 debugging n32 executables. (Debugging 64-bit executables is not yet
5442 * Unified support for hardware watchpoints in all x86 configurations.
5444 Most (if not all) native x86 configurations support hardware-assisted
5445 breakpoints and watchpoints in a unified manner. This support
5446 implements debug register sharing between watchpoints, which allows to
5447 put a virtually infinite number of watchpoints on the same address,
5448 and also supports watching regions up to 16 bytes with several debug
5451 The new maintenance command `maintenance show-debug-regs' toggles
5452 debugging print-outs in functions that insert, remove, and test
5453 watchpoints and hardware breakpoints.
5455 * Changes in the DJGPP native configuration.
5457 New command ``info dos sysinfo'' displays assorted information about
5458 the CPU, OS, memory, and DPMI server.
5460 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5461 display information about segment descriptors stored in GDT, LDT, and
5464 New commands ``info dos pde'' and ``info dos pte'' display entries
5465 from Page Directory and Page Tables (for now works with CWSDPMI only).
5466 New command ``info dos address-pte'' displays the Page Table entry for
5467 a given linear address.
5469 GDB can now pass command lines longer than 126 characters to the
5470 program being debugged (requires an update to the libdbg.a library
5471 which is part of the DJGPP development kit).
5473 DWARF2 debug info is now supported.
5475 It is now possible to `step' and `next' through calls to `longjmp'.
5477 * Changes in documentation.
5479 All GDB documentation was converted to GFDL, the GNU Free
5480 Documentation License.
5482 Tracepoints-related commands are now fully documented in the GDB
5485 TUI, the Text-mode User Interface, is now documented in the manual.
5487 Tracepoints-related commands are now fully documented in the GDB
5490 The "GDB Internals" manual now has an index. It also includes
5491 documentation of `ui_out' functions, GDB coding standards, x86
5492 hardware watchpoints, and memory region attributes.
5494 * GDB's version number moved to ``version.in''
5496 The Makefile variable VERSION has been replaced by the file
5497 ``version.in''. People creating GDB distributions should update the
5498 contents of this file.
5502 GUD support is now a standard part of the EMACS distribution.
5504 *** Changes in GDB 5.0:
5506 * Improved support for debugging FP programs on x86 targets
5508 Unified and much-improved support for debugging floating-point
5509 programs on all x86 targets. In particular, ``info float'' now
5510 displays the FP registers in the same format on all x86 targets, with
5511 greater level of detail.
5513 * Improvements and bugfixes in hardware-assisted watchpoints
5515 It is now possible to watch array elements, struct members, and
5516 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5517 on x86 targets no longer erroneously trigger when the address is
5520 * Improvements in the native DJGPP version of GDB
5522 The distribution now includes all the scripts and auxiliary files
5523 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5524 machines ``out of the box''.
5526 The DJGPP version can now debug programs that use signals. It is
5527 possible to catch signals that happened in the debuggee, deliver
5528 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5529 would kill the program being debugged.) Programs that hook hardware
5530 interrupts (keyboard, timer, etc.) can also be debugged.
5532 It is now possible to debug DJGPP programs that redirect their
5533 standard handles or switch them to raw (as opposed to cooked) mode, or
5534 even close them. The command ``run < foo > bar'' works as expected,
5535 and ``info terminal'' reports useful information about the debuggee's
5536 terminal, including raw/cooked mode, redirection, etc.
5538 The DJGPP version now uses termios functions for console I/O, which
5539 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5542 DOS-style file names with drive letters are now fully supported by
5545 It is now possible to debug DJGPP programs that switch their working
5546 directory. It is also possible to rerun the debuggee any number of
5547 times without restarting GDB; thus, you can use the same setup,
5548 breakpoints, etc. for many debugging sessions.
5550 * New native configurations
5552 ARM GNU/Linux arm*-*-linux*
5553 PowerPC GNU/Linux powerpc-*-linux*
5557 Motorola MCore mcore-*-*
5558 x86 VxWorks i[3456]86-*-vxworks*
5559 PowerPC VxWorks powerpc-*-vxworks*
5560 TI TMS320C80 tic80-*-*
5562 * OBSOLETE configurations
5564 Altos 3068 m68*-altos-*
5565 Convex c1-*-*, c2-*-*
5567 ARM RISCix arm-*-* (as host)
5570 Configurations that have been declared obsolete will be commented out,
5571 but the code will be left in place. If there is no activity to revive
5572 these configurations before the next release of GDB, the sources will
5573 be permanently REMOVED.
5575 * Gould support removed
5577 Support for the Gould PowerNode and NP1 has been removed.
5579 * New features for SVR4
5581 On SVR4 native platforms (such as Solaris), if you attach to a process
5582 without first loading a symbol file, GDB will now attempt to locate and
5583 load symbols from the running process's executable file.
5585 * Many C++ enhancements
5587 C++ support has been greatly improved. Overload resolution now works properly
5588 in almost all cases. RTTI support is on the way.
5590 * Remote targets can connect to a sub-program
5592 A popen(3) style serial-device has been added. This device starts a
5593 sub-process (such as a stand-alone simulator) and then communicates
5594 with that. The sub-program to run is specified using the syntax
5595 ``|<program> <args>'' vis:
5597 (gdb) set remotedebug 1
5598 (gdb) target extended-remote |mn10300-elf-sim program-args
5600 * MIPS 64 remote protocol
5602 A long standing bug in the mips64 remote protocol where by GDB
5603 expected certain 32 bit registers (ex SR) to be transfered as 32
5604 instead of 64 bits has been fixed.
5606 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5607 added to provide backward compatibility with older versions of GDB.
5609 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5611 The command ``set remotebinarydownload'' command has been replaced by
5612 ``set remote X-packet''. Other commands in ``set remote'' family
5613 include ``set remote P-packet''.
5615 * Breakpoint commands accept ranges.
5617 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5618 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5619 ``tracepoint passcount'' also accepts a range of tracepoints.
5621 * ``apropos'' command added.
5623 The ``apropos'' command searches through command names and
5624 documentation strings, printing out matches, making it much easier to
5625 try to find a command that does what you are looking for.
5629 A new machine oriented interface (MI) has been added to GDB. This
5630 interface is designed for debug environments running GDB as a separate
5631 process. This is part of the long term libGDB project. See the
5632 "GDB/MI" chapter of the GDB manual for further information. It can be
5633 enabled by configuring with:
5635 .../configure --enable-gdbmi
5637 *** Changes in GDB-4.18:
5639 * New native configurations
5641 HP-UX 10.20 hppa*-*-hpux10.20
5642 HP-UX 11.x hppa*-*-hpux11.0*
5643 M68K GNU/Linux m68*-*-linux*
5647 Fujitsu FR30 fr30-*-elf*
5648 Intel StrongARM strongarm-*-*
5649 Mitsubishi D30V d30v-*-*
5651 * OBSOLETE configurations
5653 Gould PowerNode, NP1 np1-*-*, pn-*-*
5655 Configurations that have been declared obsolete will be commented out,
5656 but the code will be left in place. If there is no activity to revive
5657 these configurations before the next release of GDB, the sources will
5658 be permanently REMOVED.
5662 As a compatibility experiment, GDB's source files buildsym.h and
5663 buildsym.c have been converted to pure standard C, no longer
5664 containing any K&R compatibility code. We believe that all systems in
5665 use today either come with a standard C compiler, or have a GCC port
5666 available. If this is not true, please report the affected
5667 configuration to bug-gdb@gnu.org immediately. See the README file for
5668 information about getting a standard C compiler if you don't have one
5673 GDB now uses readline 2.2.
5675 * set extension-language
5677 You can now control the mapping between filename extensions and source
5678 languages by using the `set extension-language' command. For instance,
5679 you can ask GDB to treat .c files as C++ by saying
5680 set extension-language .c c++
5681 The command `info extensions' lists all of the recognized extensions
5682 and their associated languages.
5684 * Setting processor type for PowerPC and RS/6000
5686 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5687 you can use the `set processor' command to specify what variant of the
5688 PowerPC family you are debugging. The command
5692 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5693 following PowerPC and RS6000 variants:
5695 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5696 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5698 403GC IBM PowerPC 403GC
5699 505 Motorola PowerPC 505
5700 860 Motorola PowerPC 860 or 850
5701 601 Motorola PowerPC 601
5702 602 Motorola PowerPC 602
5703 603 Motorola/IBM PowerPC 603 or 603e
5704 604 Motorola PowerPC 604 or 604e
5705 750 Motorola/IBM PowerPC 750 or 750
5707 At the moment, this command just tells GDB what to name the
5708 special-purpose processor registers. Since almost all the affected
5709 registers are inaccessible to user-level programs, this command is
5710 only useful for remote debugging in its present form.
5714 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5715 more extensive support for HP-UX. Added features include shared
5716 library support, kernel threads and hardware watchpoints for 11.00,
5717 support for HP's ANSI C and C++ compilers, and a compatibility mode
5718 for xdb and dbx commands.
5722 HP's donation includes the new concept of catchpoints, which is a
5723 generalization of the old catch command. On HP-UX, it is now possible
5724 to catch exec, fork, and vfork, as well as library loading.
5726 This means that the existing catch command has changed; its first
5727 argument now specifies the type of catch to be set up. See the
5728 output of "help catch" for a list of catchpoint types.
5730 * Debugging across forks
5732 On HP-UX, you can choose which process to debug when a fork() happens
5737 HP has donated a curses-based terminal user interface (TUI). To get
5738 it, build with --enable-tui. Although this can be enabled for any
5739 configuration, at present it only works for native HP debugging.
5741 * GDB remote protocol additions
5743 A new protocol packet 'X' that writes binary data is now available.
5744 Default behavior is to try 'X', then drop back to 'M' if the stub
5745 fails to respond. The settable variable `remotebinarydownload'
5746 allows explicit control over the use of 'X'.
5748 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5749 full 64-bit address. The command
5751 set remoteaddresssize 32
5753 can be used to revert to the old behaviour. For existing remote stubs
5754 the change should not be noticed, as the additional address information
5757 In order to assist in debugging stubs, you may use the maintenance
5758 command `packet' to send any text string to the stub. For instance,
5760 maint packet heythere
5762 sends the packet "$heythere#<checksum>". Note that it is very easy to
5763 disrupt a debugging session by sending the wrong packet at the wrong
5766 The compare-sections command allows you to compare section data on the
5767 target to what is in the executable file without uploading or
5768 downloading, by comparing CRC checksums.
5770 * Tracing can collect general expressions
5772 You may now collect general expressions at tracepoints. This requires
5773 further additions to the target-side stub; see tracepoint.c and
5774 doc/agentexpr.texi for further details.
5776 * mask-address variable for Mips
5778 For Mips targets, you may control the zeroing of the upper 32 bits of
5779 a 64-bit address by entering `set mask-address on'. This is mainly
5780 of interest to users of embedded R4xxx and R5xxx processors.
5782 * Higher serial baud rates
5784 GDB's serial code now allows you to specify baud rates 57600, 115200,
5785 230400, and 460800 baud. (Note that your host system may not be able
5786 to achieve all of these rates.)
5790 The i960 configuration now includes an initial implementation of a
5791 builtin simulator, contributed by Jim Wilson.
5794 *** Changes in GDB-4.17:
5796 * New native configurations
5798 Alpha GNU/Linux alpha*-*-linux*
5799 Unixware 2.x i[3456]86-unixware2*
5800 Irix 6.x mips*-sgi-irix6*
5801 PowerPC GNU/Linux powerpc-*-linux*
5802 PowerPC Solaris powerpcle-*-solaris*
5803 Sparc GNU/Linux sparc-*-linux*
5804 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5808 Argonaut Risc Chip (ARC) arc-*-*
5809 Hitachi H8/300S h8300*-*-*
5810 Matsushita MN10200 w/simulator mn10200-*-*
5811 Matsushita MN10300 w/simulator mn10300-*-*
5812 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5813 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5814 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5815 Mitsubishi D10V w/simulator d10v-*-*
5816 Mitsubishi M32R/D w/simulator m32r-*-elf*
5817 Tsqware Sparclet sparclet-*-*
5818 NEC V850 w/simulator v850-*-*
5820 * New debugging protocols
5822 ARM with RDI protocol arm*-*-*
5823 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5824 DDB and LSI variants of PMON protocol mips*-*-*
5825 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5826 PowerPC with SDS protocol powerpc{,le}-*-eabi
5827 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5831 All configurations can now understand and use the DWARF 2 debugging
5832 format. The choice is automatic, if the symbol file contains DWARF 2
5837 GDB now includes basic Java language support. This support is
5838 only useful with Java compilers that produce native machine code.
5840 * solib-absolute-prefix and solib-search-path
5842 For SunOS and SVR4 shared libraries, you may now set the prefix for
5843 loading absolute shared library symbol files, and the search path for
5844 locating non-absolute shared library symbol files.
5846 * Live range splitting
5848 GDB can now effectively debug code for which GCC has performed live
5849 range splitting as part of its optimization. See gdb/doc/LRS for
5850 more details on the expected format of the stabs information.
5854 GDB's support for the GNU Hurd, including thread debugging, has been
5855 updated to work with current versions of the Hurd.
5859 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5860 instruction set. ARM GDB automatically detects when Thumb
5861 instructions are in use, and adjusts disassembly and backtracing
5866 GDB's MIPS target configurations now handle the MIP16 16-bit
5871 GDB now includes support for overlays; if an executable has been
5872 linked such that multiple sections are based at the same address, GDB
5873 will decide which section to use for symbolic info. You can choose to
5874 control the decision manually, using overlay commands, or implement
5875 additional target-side support and use "overlay load-target" to bring
5876 in the overlay mapping. Do "help overlay" for more detail.
5880 The command "info symbol <address>" displays information about
5881 the symbol at the specified address.
5885 The standard remote protocol now includes an extension that allows
5886 asynchronous collection and display of trace data. This requires
5887 extensive support in the target-side debugging stub. Tracing mode
5888 includes a new interaction mode in GDB and new commands: see the
5889 file tracepoint.c for more details.
5893 Configurations for embedded MIPS now include a simulator contributed
5894 by Cygnus Solutions. The simulator supports the instruction sets
5895 of most MIPS variants.
5899 Sparc configurations may now include the ERC32 simulator contributed
5900 by the European Space Agency. The simulator is not built into
5901 Sparc targets by default; configure with --enable-sim to include it.
5905 For target configurations that may include multiple variants of a
5906 basic architecture (such as MIPS and SH), you may now set the
5907 architecture explicitly. "set arch" sets, "info arch" lists
5908 the possible architectures.
5910 *** Changes in GDB-4.16:
5912 * New native configurations
5914 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5915 M68K NetBSD m68k-*-netbsd*
5916 PowerPC AIX 4.x powerpc-*-aix*
5917 PowerPC MacOS powerpc-*-macos*
5918 PowerPC Windows NT powerpcle-*-cygwin32
5919 RS/6000 AIX 4.x rs6000-*-aix4*
5923 ARM with RDP protocol arm-*-*
5924 I960 with MON960 i960-*-coff
5925 MIPS VxWorks mips*-*-vxworks*
5926 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5927 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5929 Matra Sparclet sparclet-*-*
5933 The powerpc-eabi configuration now includes the PSIM simulator,
5934 contributed by Andrew Cagney, with assistance from Mike Meissner.
5935 PSIM is a very elaborate model of the PowerPC, including not only
5936 basic instruction set execution, but also details of execution unit
5937 performance and I/O hardware. See sim/ppc/README for more details.
5941 GDB now works with Solaris 2.5.
5943 * Windows 95/NT native
5945 GDB will now work as a native debugger on Windows 95 and Windows NT.
5946 To build it from source, you must use the "gnu-win32" environment,
5947 which uses a DLL to emulate enough of Unix to run the GNU tools.
5948 Further information, binaries, and sources are available at
5949 ftp.cygnus.com, under pub/gnu-win32.
5951 * dont-repeat command
5953 If a user-defined command includes the command `dont-repeat', then the
5954 command will not be repeated if the user just types return. This is
5955 useful if the command is time-consuming to run, so that accidental
5956 extra keystrokes don't run the same command many times.
5958 * Send break instead of ^C
5960 The standard remote protocol now includes an option to send a break
5961 rather than a ^C to the target in order to interrupt it. By default,
5962 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5964 * Remote protocol timeout
5966 The standard remote protocol includes a new variable `remotetimeout'
5967 that allows you to set the number of seconds before GDB gives up trying
5968 to read from the target. The default value is 2.
5970 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
5972 By default GDB will automatically keep track of objects as they are
5973 loaded and unloaded by the dynamic linker. By using the command `set
5974 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
5975 when shared library events occur, thus allowing you to set breakpoints
5976 in shared libraries which are explicitly loaded by the inferior.
5978 Note this feature does not work on hpux8. On hpux9 you must link
5979 /usr/lib/end.o into your program. This feature should work
5980 automatically on hpux10.
5982 * Irix 5.x hardware watchpoint support
5984 Irix 5 configurations now support the use of hardware watchpoints.
5986 * Mips protocol "SYN garbage limit"
5988 When debugging a Mips target using the `target mips' protocol, you
5989 may set the number of characters that GDB will ignore by setting
5990 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
5991 every character. The default value is 1050.
5993 * Recording and replaying remote debug sessions
5995 If you set `remotelogfile' to the name of a file, gdb will write to it
5996 a recording of a remote debug session. This recording may then be
5997 replayed back to gdb using "gdbreplay". See gdbserver/README for
5998 details. This is useful when you have a problem with GDB while doing
5999 remote debugging; you can make a recording of the session and send it
6000 to someone else, who can then recreate the problem.
6002 * Speedups for remote debugging
6004 GDB includes speedups for downloading and stepping MIPS systems using
6005 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6006 and more efficient S-record downloading.
6008 * Memory use reductions and statistics collection
6010 GDB now uses less memory and reports statistics about memory usage.
6011 Try the `maint print statistics' command, for example.
6013 *** Changes in GDB-4.15:
6015 * Psymtabs for XCOFF
6017 The symbol reader for AIX GDB now uses partial symbol tables. This
6018 can greatly improve startup time, especially for large executables.
6020 * Remote targets use caching
6022 Remote targets now use a data cache to speed up communication with the
6023 remote side. The data cache could lead to incorrect results because
6024 it doesn't know about volatile variables, thus making it impossible to
6025 debug targets which use memory mapped I/O devices. `set remotecache
6026 off' turns the the data cache off.
6028 * Remote targets may have threads
6030 The standard remote protocol now includes support for multiple threads
6031 in the target system, using new protocol commands 'H' and 'T'. See
6032 gdb/remote.c for details.
6036 If GDB is configured with `--enable-netrom', then it will include
6037 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6038 acts as though it is a bank of ROM on the target board, but you can
6039 write into it over the network. GDB's support consists only of
6040 support for fast loading into the emulated ROM; to debug, you must use
6041 another protocol, such as standard remote protocol. The usual
6042 sequence is something like
6044 target nrom <netrom-hostname>
6046 target remote <netrom-hostname>:1235
6050 GDB now includes support for the Apple Macintosh, as a host only. It
6051 may be run as either an MPW tool or as a standalone application, and
6052 it can debug through the serial port. All the usual GDB commands are
6053 available, but to the target command, you must supply "serial" as the
6054 device type instead of "/dev/ttyXX". See mpw-README in the main
6055 directory for more information on how to build. The MPW configuration
6056 scripts */mpw-config.in support only a few targets, and only the
6057 mips-idt-ecoff target has been tested.
6061 GDB configuration now uses autoconf. This is not user-visible,
6062 but does simplify configuration and building.
6066 GDB now supports hpux10.
6068 *** Changes in GDB-4.14:
6070 * New native configurations
6072 x86 FreeBSD i[345]86-*-freebsd
6073 x86 NetBSD i[345]86-*-netbsd
6074 NS32k NetBSD ns32k-*-netbsd
6075 Sparc NetBSD sparc-*-netbsd
6079 A29K VxWorks a29k-*-vxworks
6080 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6081 CPU32 EST-300 emulator m68*-*-est*
6082 PowerPC ELF powerpc-*-elf
6085 * Alpha OSF/1 support for procfs
6087 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6088 possible to attach to running processes. As the mounting of the /proc
6089 filesystem is optional on the Alpha, GDB automatically determines
6090 the availability of /proc during startup. This can lead to problems
6091 if /proc is unmounted after GDB has been started.
6093 * Arguments to user-defined commands
6095 User commands may accept up to 10 arguments separated by whitespace.
6096 Arguments are accessed within the user command via $arg0..$arg9. A
6099 print $arg0 + $arg1 + $arg2
6101 To execute the command use:
6104 Defines the command "adder" which prints the sum of its three arguments.
6105 Note the arguments are text substitutions, so they may reference variables,
6106 use complex expressions, or even perform inferior function calls.
6108 * New `if' and `while' commands
6110 This makes it possible to write more sophisticated user-defined
6111 commands. Both commands take a single argument, which is the
6112 expression to evaluate, and must be followed by the commands to
6113 execute, one per line, if the expression is nonzero, the list being
6114 terminated by the word `end'. The `if' command list may include an
6115 `else' word, which causes the following commands to be executed only
6116 if the expression is zero.
6118 * Fortran source language mode
6120 GDB now includes partial support for Fortran 77. It will recognize
6121 Fortran programs and can evaluate a subset of Fortran expressions, but
6122 variables and functions may not be handled correctly. GDB will work
6123 with G77, but does not yet know much about symbols emitted by other
6126 * Better HPUX support
6128 Most debugging facilities now work on dynamic executables for HPPAs
6129 running hpux9 or later. You can attach to running dynamically linked
6130 processes, but by default the dynamic libraries will be read-only, so
6131 for instance you won't be able to put breakpoints in them. To change
6132 that behavior do the following before running the program:
6138 This will cause the libraries to be mapped private and read-write.
6139 To revert to the normal behavior, do this:
6145 You cannot set breakpoints or examine data in the library until after
6146 the library is loaded if the function/data symbols do not have
6149 GDB can now also read debug symbols produced by the HP C compiler on
6150 HPPAs (sorry, no C++, Fortran or 68k support).
6152 * Target byte order now dynamically selectable
6154 You can choose which byte order to use with a target system, via the
6155 commands "set endian big" and "set endian little", and you can see the
6156 current setting by using "show endian". You can also give the command
6157 "set endian auto", in which case GDB will use the byte order
6158 associated with the executable. Currently, only embedded MIPS
6159 configurations support dynamic selection of target byte order.
6161 * New DOS host serial code
6163 This version uses DPMI interrupts to handle buffered I/O, so you
6164 no longer need to run asynctsr when debugging boards connected to
6167 *** Changes in GDB-4.13:
6169 * New "complete" command
6171 This lists all the possible completions for the rest of the line, if it
6172 were to be given as a command itself. This is intended for use by emacs.
6174 * Trailing space optional in prompt
6176 "set prompt" no longer adds a space for you after the prompt you set. This
6177 allows you to set a prompt which ends in a space or one that does not.
6179 * Breakpoint hit counts
6181 "info break" now displays a count of the number of times the breakpoint
6182 has been hit. This is especially useful in conjunction with "ignore"; you
6183 can ignore a large number of breakpoint hits, look at the breakpoint info
6184 to see how many times the breakpoint was hit, then run again, ignoring one
6185 less than that number, and this will get you quickly to the last hit of
6188 * Ability to stop printing at NULL character
6190 "set print null-stop" will cause GDB to stop printing the characters of
6191 an array when the first NULL is encountered. This is useful when large
6192 arrays actually contain only short strings.
6194 * Shared library breakpoints
6196 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6197 breakpoints in shared libraries before the executable is run.
6199 * Hardware watchpoints
6201 There is a new hardware breakpoint for the watch command for sparclite
6202 targets. See gdb/sparclite/hw_breakpoint.note.
6204 Hardware watchpoints are also now supported under GNU/Linux.
6208 Annotations have been added. These are for use with graphical interfaces,
6209 and are still experimental. Currently only gdba.el uses these.
6211 * Improved Irix 5 support
6213 GDB now works properly with Irix 5.2.
6215 * Improved HPPA support
6217 GDB now works properly with the latest GCC and GAS.
6219 * New native configurations
6221 Sequent PTX4 i[34]86-sequent-ptx4
6222 HPPA running OSF/1 hppa*-*-osf*
6223 Atari TT running SVR4 m68*-*-sysv4*
6224 RS/6000 LynxOS rs6000-*-lynxos*
6228 OS/9000 i[34]86-*-os9k
6229 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6232 * Hitachi SH7000 and E7000-PC ICE support
6234 There is now support for communicating with the Hitachi E7000-PC ICE.
6235 This is available automatically when GDB is configured for the SH.
6239 As usual, a variety of small fixes and improvements, both generic
6240 and configuration-specific. See the ChangeLog for more detail.
6242 *** Changes in GDB-4.12:
6244 * Irix 5 is now supported
6248 GDB-4.12 on the HPPA has a number of changes which make it unable
6249 to debug the output from the currently released versions of GCC and
6250 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6251 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6252 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6255 *** Changes in GDB-4.11:
6257 * User visible changes:
6261 The "set remotedebug" option is now consistent between the mips remote
6262 target, remote targets using the gdb-specific protocol, UDI (AMD's
6263 debug protocol for the 29k) and the 88k bug monitor. It is now an
6264 integer specifying a debug level (normally 0 or 1, but 2 means more
6265 debugging info for the mips target).
6267 * DEC Alpha native support
6269 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6270 debug info, but GDB works fairly well with the DEC compiler and should
6271 work with a future GCC release. See the README file for a few
6272 Alpha-specific notes.
6274 * Preliminary thread implementation
6276 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6278 * LynxOS native and target support for 386
6280 This release has been hosted on LynxOS 2.2, and also can be configured
6281 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6284 * Improvements in C++ mangling/demangling.
6286 This release has much better g++ debugging, specifically in name
6287 mangling/demangling, virtual function calls, print virtual table,
6288 call methods, ...etc.
6290 *** Changes in GDB-4.10:
6292 * User visible changes:
6294 Remote debugging using the GDB-specific (`target remote') protocol now
6295 supports the `load' command. This is only useful if you have some
6296 other way of getting the stub to the target system, and you can put it
6297 somewhere in memory where it won't get clobbered by the download.
6299 Filename completion now works.
6301 When run under emacs mode, the "info line" command now causes the
6302 arrow to point to the line specified. Also, "info line" prints
6303 addresses in symbolic form (as well as hex).
6305 All vxworks based targets now support a user settable option, called
6306 vxworks-timeout. This option represents the number of seconds gdb
6307 should wait for responses to rpc's. You might want to use this if
6308 your vxworks target is, perhaps, a slow software simulator or happens
6309 to be on the far side of a thin network line.
6313 This release contains support for using a DEC alpha as a GDB host for
6314 cross debugging. Native alpha debugging is not supported yet.
6317 *** Changes in GDB-4.9:
6321 This is the first GDB release which is accompanied by a matching testsuite.
6322 The testsuite requires installation of dejagnu, which should be available
6323 via ftp from most sites that carry GNU software.
6327 'Cfront' style demangling has had its name changed to 'ARM' style, to
6328 emphasize that it was written from the specifications in the C++ Annotated
6329 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6330 disclaimers, it still generated too much confusion with users attempting to
6331 use gdb with AT&T cfront.
6335 GDB now uses a standard remote interface to a simulator library.
6336 So far, the library contains simulators for the Zilog Z8001/2, the
6337 Hitachi H8/300, H8/500 and Super-H.
6339 * New targets supported
6341 H8/300 simulator h8300-hitachi-hms or h8300hms
6342 H8/500 simulator h8500-hitachi-hms or h8500hms
6343 SH simulator sh-hitachi-hms or sh
6344 Z8000 simulator z8k-zilog-none or z8ksim
6345 IDT MIPS board over serial line mips-idt-ecoff
6347 Cross-debugging to GO32 targets is supported. It requires a custom
6348 version of the i386-stub.c module which is integrated with the
6349 GO32 memory extender.
6351 * New remote protocols
6353 MIPS remote debugging protocol.
6355 * New source languages supported
6357 This version includes preliminary support for Chill, a Pascal like language
6358 used by telecommunications companies. Chill support is also being integrated
6359 into the GNU compiler, but we don't know when it will be publically available.
6362 *** Changes in GDB-4.8:
6364 * HP Precision Architecture supported
6366 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6367 version of this support was available as a set of patches from the
6368 University of Utah. GDB does not support debugging of programs
6369 compiled with the HP compiler, because HP will not document their file
6370 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6371 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6373 Many problems in the preliminary version have been fixed.
6375 * Faster and better demangling
6377 We have improved template demangling and fixed numerous bugs in the GNU style
6378 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6379 character types (wchar_t) are now supported. Demangling of each symbol is now
6380 only done once, and is cached when the symbol table for a file is read in.
6381 This results in a small increase in memory usage for C programs, a moderate
6382 increase in memory usage for C++ programs, and a fantastic speedup in
6385 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6386 from the specifications in the Annotated Reference Manual, which AT&T's
6387 compiler does not actually implement.
6389 * G++ multiple inheritance compiler problem
6391 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6392 inheritance lattices was reworked to properly discover ambiguities. We
6393 recently found an example which causes this new algorithm to fail in a
6394 very subtle way, producing bad debug information for those classes.
6395 The file 'gcc.patch' (in this directory) can be applied to gcc to
6396 circumvent the problem. A future GCC release will contain a complete
6399 The previous G++ debug info problem (mentioned below for the gdb-4.7
6400 release) is fixed in gcc version 2.3.2.
6402 * Improved configure script
6404 The `configure' script will now attempt to guess your system type if
6405 you don't supply a host system type. The old scheme of supplying a
6406 host system triplet is preferable over using this. All the magic is
6407 done in the new `config.guess' script. Examine it for details.
6409 We have also brought our configure script much more in line with the FSF's
6410 version. It now supports the --with-xxx options. In particular,
6411 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6412 The resulting GDB will not be able to read arbitrary object file formats --
6413 only the format ``expected'' to be used on the configured target system.
6414 We hope to make this the default in a future release.
6416 * Documentation improvements
6418 There's new internal documentation on how to modify GDB, and how to
6419 produce clean changes to the code. We implore people to read it
6420 before submitting changes.
6422 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6423 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6424 `info' files are also provided. To build `info' files from scratch,
6425 you will need the latest `makeinfo' release, which will be available in
6426 a future texinfo-X.Y release.
6428 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6429 We're not sure exactly which versions have this problem, but it has
6430 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6431 or better. If that isn't possible, there is a patch in
6432 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6433 around this problem.
6437 GDB now supports array constants that can be used in expressions typed in by
6438 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6439 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6442 The new directory `gdb/sparclite' contains a program that demonstrates
6443 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6445 * New native hosts supported
6447 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6448 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6450 * New targets supported
6452 AMD 29k family via UDI a29k-amd-udi or udi29k
6454 * New file formats supported
6456 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6457 HPUX core files, and SCO 3.2v2 core files.
6461 Attaching to processes now works again; thanks for the many bug reports.
6463 We have also stomped on a bunch of core dumps caused by
6464 printf_filtered("%s") problems.
6466 We eliminated a copyright problem on the rpc and ptrace header files
6467 for VxWorks, which was discovered at the last minute during the 4.7
6468 release. You should now be able to build a VxWorks GDB.
6470 You can now interrupt gdb while an attached process is running. This
6471 will cause the attached process to stop, and give control back to GDB.
6473 We fixed problems caused by using too many file descriptors
6474 for reading symbols from object files and libraries. This was
6475 especially a problem for programs that used many (~100) shared
6478 The `step' command now only enters a subroutine if there is line number
6479 information for the subroutine. Otherwise it acts like the `next'
6480 command. Previously, `step' would enter subroutines if there was
6481 any debugging information about the routine. This avoids problems
6482 when using `cc -g1' on MIPS machines.
6484 * Internal improvements
6486 GDB's internal interfaces have been improved to make it easier to support
6487 debugging of multiple languages in the future.
6489 GDB now uses a common structure for symbol information internally.
6490 Minimal symbols (derived from linkage symbols in object files), partial
6491 symbols (from a quick scan of debug information), and full symbols
6492 contain a common subset of information, making it easier to write
6493 shared code that handles any of them.
6495 * New command line options
6497 We now accept --silent as an alias for --quiet.
6501 The memory-mapped-malloc library is now licensed under the GNU Library
6502 General Public License.
6504 *** Changes in GDB-4.7:
6506 * Host/native/target split
6508 GDB has had some major internal surgery to untangle the support for
6509 hosts and remote targets. Now, when you configure GDB for a remote
6510 target, it will no longer load in all of the support for debugging
6511 local programs on the host. When fully completed and tested, this will
6512 ensure that arbitrary host/target combinations are possible.
6514 The primary conceptual shift is to separate the non-portable code in
6515 GDB into three categories. Host specific code is required any time GDB
6516 is compiled on that host, regardless of the target. Target specific
6517 code relates to the peculiarities of the target, but can be compiled on
6518 any host. Native specific code is everything else: it can only be
6519 built when the host and target are the same system. Child process
6520 handling and core file support are two common `native' examples.
6522 GDB's use of /proc for controlling Unix child processes is now cleaner.
6523 It has been split out into a single module under the `target_ops' vector,
6524 plus two native-dependent functions for each system that uses /proc.
6526 * New hosts supported
6528 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6529 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6530 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6532 * New targets supported
6534 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6535 68030 and CPU32 m68030-*-*, m68332-*-*
6537 * New native hosts supported
6539 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6540 (386bsd is not well tested yet)
6541 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6543 * New file formats supported
6545 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6546 supports reading of `a.out.adobe' object files, which are an a.out
6547 format extended with minimal information about multiple sections.
6551 `show copying' is the same as the old `info copying'.
6552 `show warranty' is the same as `info warrantee'.
6553 These were renamed for consistency. The old commands continue to work.
6555 `info handle' is a new alias for `info signals'.
6557 You can now define pre-command hooks, which attach arbitrary command
6558 scripts to any command. The commands in the hook will be executed
6559 prior to the user's command. You can also create a hook which will be
6560 executed whenever the program stops. See gdb.texinfo.
6564 We now deal with Cfront style name mangling, and can even extract type
6565 info from mangled symbols. GDB can automatically figure out which
6566 symbol mangling style your C++ compiler uses.
6568 Calling of methods and virtual functions has been improved as well.
6572 The crash that occured when debugging Sun Ansi-C compiled binaries is
6573 fixed. This was due to mishandling of the extra N_SO stabs output
6576 We also finally got Ultrix 4.2 running in house, and fixed core file
6577 support, with help from a dozen people on the net.
6579 John M. Farrell discovered that the reason that single-stepping was so
6580 slow on all of the Mips based platforms (primarily SGI and DEC) was
6581 that we were trying to demangle and lookup a symbol used for internal
6582 purposes on every instruction that was being stepped through. Changing
6583 the name of that symbol so that it couldn't be mistaken for a C++
6584 mangled symbol sped things up a great deal.
6586 Rich Pixley sped up symbol lookups in general by getting much smarter
6587 about when C++ symbol mangling is necessary. This should make symbol
6588 completion (TAB on the command line) much faster. It's not as fast as
6589 we'd like, but it's significantly faster than gdb-4.6.
6593 A new user controllable variable 'call_scratch_address' can
6594 specify the location of a scratch area to be used when GDB
6595 calls a function in the target. This is necessary because the
6596 usual method of putting the scratch area on the stack does not work
6597 in systems that have separate instruction and data spaces.
6599 We integrated changes to support the 29k UDI (Universal Debugger
6600 Interface), but discovered at the last minute that we didn't have all
6601 of the appropriate copyright paperwork. We are working with AMD to
6602 resolve this, and hope to have it available soon.
6606 We have sped up the remote serial line protocol, especially for targets
6607 with lots of registers. It now supports a new `expedited status' ('T')
6608 message which can be used in place of the existing 'S' status message.
6609 This allows the remote stub to send only the registers that GDB
6610 needs to make a quick decision about single-stepping or conditional
6611 breakpoints, eliminating the need to fetch the entire register set for
6612 each instruction being stepped through.
6614 The GDB remote serial protocol now implements a write-through cache for
6615 registers, only re-reading the registers if the target has run.
6617 There is also a new remote serial stub for SPARC processors. You can
6618 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6619 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6620 processor with a serial port.
6624 Configure.in files have become much easier to read and modify. A new
6625 `table driven' format makes it more obvious what configurations are
6626 supported, and what files each one uses.
6630 There is a new opcodes library which will eventually contain all of the
6631 disassembly routines and opcode tables. At present, it only contains
6632 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6633 disassembler (binutils/objdump) to share these routines.
6635 The libiberty library is now copylefted under the GNU Library General
6636 Public License. This allows more liberal use, and was done so libg++
6637 can use it. This makes no difference to GDB, since the Library License
6638 grants all the rights from the General Public License.
6642 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6643 reference to the stabs symbol info used by the debugger. It is (as far
6644 as we know) the only published document on this fascinating topic. We
6645 encourage you to read it, compare it to the stabs information on your
6646 system, and send improvements on the document in general (to
6647 bug-gdb@prep.ai.mit.edu).
6649 And, of course, many bugs have been fixed.
6652 *** Changes in GDB-4.6:
6654 * Better support for C++ function names
6656 GDB now accepts as input the "demangled form" of C++ overloaded function
6657 names and member function names, and can do command completion on such names
6658 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6659 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6660 Make use of command completion, it is your friend.
6662 GDB also now accepts a variety of C++ mangled symbol formats. They are
6663 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6664 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6665 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6666 for the list of formats.
6668 * G++ symbol mangling problem
6670 Recent versions of gcc have a bug in how they emit debugging information for
6671 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6672 directory) can be applied to gcc to fix the problem. Alternatively, if you
6673 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6674 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6675 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6678 * New 'maintenance' command
6680 All of the commands related to hacking GDB internals have been moved out of
6681 the main command set, and now live behind the 'maintenance' command. This
6682 can also be abbreviated as 'mt'. The following changes were made:
6684 dump-me -> maintenance dump-me
6685 info all-breakpoints -> maintenance info breakpoints
6686 printmsyms -> maintenance print msyms
6687 printobjfiles -> maintenance print objfiles
6688 printpsyms -> maintenance print psymbols
6689 printsyms -> maintenance print symbols
6691 The following commands are new:
6693 maintenance demangle Call internal GDB demangler routine to
6694 demangle a C++ link name and prints the result.
6695 maintenance print type Print a type chain for a given symbol
6697 * Change to .gdbinit file processing
6699 We now read the $HOME/.gdbinit file before processing the argv arguments
6700 (e.g. reading symbol files or core files). This allows global parameters to
6701 be set, which will apply during the symbol reading. The ./.gdbinit is still
6702 read after argv processing.
6704 * New hosts supported
6706 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6708 GNU/Linux support i386-unknown-linux or linux
6710 We are also including code to support the HP/PA running BSD and HPUX. This
6711 is almost guaranteed not to work, as we didn't have time to test or build it
6712 for this release. We are including it so that the more adventurous (or
6713 masochistic) of you can play with it. We also had major problems with the
6714 fact that the compiler that we got from HP doesn't support the -g option.
6717 * New targets supported
6719 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6721 * More smarts about finding #include files
6723 GDB now remembers the compilation directory for all include files, and for
6724 all files from which C is generated (like yacc and lex sources). This
6725 greatly improves GDB's ability to find yacc/lex sources, and include files,
6726 especially if you are debugging your program from a directory different from
6727 the one that contains your sources.
6729 We also fixed a bug which caused difficulty with listing and setting
6730 breakpoints in include files which contain C code. (In the past, you had to
6731 try twice in order to list an include file that you hadn't looked at before.)
6733 * Interesting infernals change
6735 GDB now deals with arbitrary numbers of sections, where the symbols for each
6736 section must be relocated relative to that section's landing place in the
6737 target's address space. This work was needed to support ELF with embedded
6738 stabs used by Solaris-2.0.
6740 * Bug fixes (of course!)
6742 There have been loads of fixes for the following things:
6743 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6744 i960, stabs, DOS(GO32), procfs, etc...
6746 See the ChangeLog for details.
6748 *** Changes in GDB-4.5:
6750 * New machines supported (host and target)
6752 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6754 SGI Irix-4.x mips-sgi-irix4 or iris4
6756 * New malloc package
6758 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6759 Mmalloc is capable of handling mutiple heaps of memory. It is also
6760 capable of saving a heap to a file, and then mapping it back in later.
6761 This can be used to greatly speedup the startup of GDB by using a
6762 pre-parsed symbol table which lives in a mmalloc managed heap. For
6763 more details, please read mmalloc/mmalloc.texi.
6767 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6768 'help info proc' for details.
6770 * MIPS ecoff symbol table format
6772 The code that reads MIPS symbol table format is now supported on all hosts.
6773 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6776 * File name changes for MS-DOS
6778 Many files in the config directories have been renamed to make it easier to
6779 support GDB on MS-DOSe systems (which have very restrictive file name
6780 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6781 environment) is close to working but has some remaining problems. Note
6782 that debugging of DOS programs is not supported, due to limitations
6783 in the ``operating system'', but it can be used to host cross-debugging.
6785 * Cross byte order fixes
6787 Many fixes have been made to support cross debugging of Sparc and MIPS
6788 targets from hosts whose byte order differs.
6790 * New -mapped and -readnow options
6792 If memory-mapped files are available on your system through the 'mmap'
6793 system call, you can use the -mapped option on the `file' or
6794 `symbol-file' commands to cause GDB to write the symbols from your
6795 program into a reusable file. If the program you are debugging is
6796 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6797 Future GDB debugging sessions will notice the presence of this file,
6798 and will quickly map in symbol information from it, rather than reading
6799 the symbol table from the executable program. Using the '-mapped'
6800 option in a GDB `file' or `symbol-file' command has the same effect as
6801 starting GDB with the '-mapped' command-line option.
6803 You can cause GDB to read the entire symbol table immediately by using
6804 the '-readnow' option with any of the commands that load symbol table
6805 information (or on the GDB command line). This makes the command
6806 slower, but makes future operations faster.
6808 The -mapped and -readnow options are typically combined in order to
6809 build a `fred.syms' file that contains complete symbol information.
6810 A simple GDB invocation to do nothing but build a `.syms' file for future
6813 gdb -batch -nx -mapped -readnow programname
6815 The `.syms' file is specific to the host machine on which GDB is run.
6816 It holds an exact image of GDB's internal symbol table. It cannot be
6817 shared across multiple host platforms.
6819 * longjmp() handling
6821 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6822 siglongjmp() without losing control. This feature has not yet been ported to
6823 all systems. It currently works on many 386 platforms, all MIPS-based
6824 platforms (SGI, DECstation, etc), and Sun3/4.
6828 Preliminary work has been put in to support the new Solaris OS from Sun. At
6829 this time, it can control and debug processes, but it is not capable of
6834 As always, many many bug fixes. The major areas were with g++, and mipsread.
6835 People using the MIPS-based platforms should experience fewer mysterious
6836 crashes and trashed symbol tables.
6838 *** Changes in GDB-4.4:
6840 * New machines supported (host and target)
6842 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6844 BSD Reno on Vax vax-dec-bsd
6845 Ultrix on Vax vax-dec-ultrix
6847 * New machines supported (target)
6849 AMD 29000 embedded, using EBMON a29k-none-none
6853 GDB continues to improve its handling of C++. `References' work better.
6854 The demangler has also been improved, and now deals with symbols mangled as
6855 per the Annotated C++ Reference Guide.
6857 GDB also now handles `stabs' symbol information embedded in MIPS
6858 `ecoff' symbol tables. Since the ecoff format was not easily
6859 extensible to handle new languages such as C++, this appeared to be a
6860 good way to put C++ debugging info into MIPS binaries. This option
6861 will be supported in the GNU C compiler, version 2, when it is
6864 * New features for SVR4
6866 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6867 shared libraries. Debugging dynamically linked programs should present
6868 only minor differences from debugging statically linked programs.
6870 The `info proc' command will print out information about any process
6871 on an SVR4 system (including the one you are debugging). At the moment,
6872 it prints the address mappings of the process.
6874 If you bring up GDB on another SVR4 system, please send mail to
6875 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6877 * Better dynamic linking support in SunOS
6879 Reading symbols from shared libraries which contain debugging symbols
6880 now works properly. However, there remain issues such as automatic
6881 skipping of `transfer vector' code during function calls, which
6882 make it harder to debug code in a shared library, than to debug the
6883 same code linked statically.
6887 GDB is now using the latest `getopt' routines from the FSF. This
6888 version accepts the -- prefix for options with long names. GDB will
6889 continue to accept the old forms (-option and +option) as well.
6890 Various single letter abbreviations for options have been explicity
6891 added to the option table so that they won't get overshadowed in the
6892 future by other options that begin with the same letter.
6896 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6897 Many assorted bugs have been handled. Many more remain to be handled.
6898 See the various ChangeLog files (primarily in gdb and bfd) for details.
6901 *** Changes in GDB-4.3:
6903 * New machines supported (host and target)
6905 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6906 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6907 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6909 * Almost SCO Unix support
6911 We had hoped to support:
6912 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6913 (except for core file support), but we discovered very late in the release
6914 that it has problems with process groups that render gdb unusable. Sorry
6915 about that. I encourage people to fix it and post the fixes.
6917 * Preliminary ELF and DWARF support
6919 GDB can read ELF object files on System V Release 4, and can handle
6920 debugging records for C, in DWARF format, in ELF files. This support
6921 is preliminary. If you bring up GDB on another SVR4 system, please
6922 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6927 GDB now uses the latest `readline' library. One user-visible change
6928 is that two tabs will list possible command completions, which previously
6929 required typing M-? (meta-question mark, or ESC ?).
6933 The `stepi' bug that many of you noticed has been squashed.
6934 Many bugs in C++ have been handled. Many more remain to be handled.
6935 See the various ChangeLog files (primarily in gdb and bfd) for details.
6937 * State of the MIPS world (in case you wondered):
6939 GDB can understand the symbol tables emitted by the compilers
6940 supplied by most vendors of MIPS-based machines, including DEC. These
6941 symbol tables are in a format that essentially nobody else uses.
6943 Some versions of gcc come with an assembler post-processor called
6944 mips-tfile. This program is required if you want to do source-level
6945 debugging of gcc-compiled programs. I believe FSF does not ship
6946 mips-tfile with gcc version 1, but it will eventually come with gcc
6949 Debugging of g++ output remains a problem. g++ version 1.xx does not
6950 really support it at all. (If you're lucky, you should be able to get
6951 line numbers and stack traces to work, but no parameters or local
6952 variables.) With some work it should be possible to improve the
6955 When gcc version 2 is released, you will have somewhat better luck.
6956 However, even then you will get confusing results for inheritance and
6959 We will eventually provide full debugging of g++ output on
6960 DECstations. This will probably involve some kind of stabs-in-ecoff
6961 encapulation, but the details have not been worked out yet.
6964 *** Changes in GDB-4.2:
6966 * Improved configuration
6968 Only one copy of `configure' exists now, and it is not self-modifying.
6969 Porting BFD is simpler.
6973 The `step' and `next' commands now only stop at the first instruction
6974 of a source line. This prevents the multiple stops that used to occur
6975 in switch statements, for-loops, etc. `Step' continues to stop if a
6976 function that has debugging information is called within the line.
6980 Lots of small bugs fixed. More remain.
6982 * New host supported (not target)
6984 Intel 386 PC clone running Mach i386-none-mach
6987 *** Changes in GDB-4.1:
6989 * Multiple source language support
6991 GDB now has internal scaffolding to handle several source languages.
6992 It determines the type of each source file from its filename extension,
6993 and will switch expression parsing and number formatting to match the
6994 language of the function in the currently selected stack frame.
6995 You can also specifically set the language to be used, with
6996 `set language c' or `set language modula-2'.
7000 GDB now has preliminary support for the GNU Modula-2 compiler,
7001 currently under development at the State University of New York at
7002 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7003 continue through the fall of 1991 and into 1992.
7005 Other Modula-2 compilers are currently not supported, and attempting to
7006 debug programs compiled with them will likely result in an error as the
7007 symbol table is read. Feel free to work on it, though!
7009 There are hooks in GDB for strict type checking and range checking,
7010 in the `Modula-2 philosophy', but they do not currently work.
7014 GDB can now write to executable and core files (e.g. patch
7015 a variable's value). You must turn this switch on, specify
7016 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7017 by assigning a new value to a variable. Modifications take
7020 * Automatic SunOS shared library reading
7022 When you run your program, GDB automatically determines where its
7023 shared libraries (if any) have been loaded, and reads their symbols.
7024 The `share' command is no longer needed. This also works when
7025 examining core files.
7029 You can specify the number of lines that the `list' command shows.
7032 * New machines supported (host and target)
7034 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7035 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7036 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7038 * New hosts supported (not targets)
7040 IBM RT/PC: romp-ibm-aix or rtpc
7042 * New targets supported (not hosts)
7044 AMD 29000 embedded with COFF a29k-none-coff
7045 AMD 29000 embedded with a.out a29k-none-aout
7046 Ultracomputer remote kernel debug a29k-nyu-kern
7048 * New remote interfaces
7054 *** Changes in GDB-4.0:
7058 Wide output is wrapped at good places to make the output more readable.
7060 Gdb now supports cross-debugging from a host machine of one type to a
7061 target machine of another type. Communication with the target system
7062 is over serial lines. The ``target'' command handles connecting to the
7063 remote system; the ``load'' command will download a program into the
7064 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7065 also supports debugging of realtime processes running under VxWorks,
7066 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7067 stub on the target system.
7069 New CPUs supported include the AMD 29000 and Intel 960.
7071 GDB now reads object files and symbol tables via a ``binary file''
7072 library, which allows a single copy of GDB to debug programs of multiple
7073 object file types such as a.out and coff.
7075 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7076 refcard.dvi and refcard.ps are available to format it).
7079 * Control-Variable user interface simplified
7081 All variables that control the operation of the debugger can be set
7082 by the ``set'' command, and displayed by the ``show'' command.
7084 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7085 ``Show prompt'' produces the response:
7086 Gdb's prompt is new-gdb=>.
7088 What follows are the NEW set commands. The command ``help set'' will
7089 print a complete list of old and new set commands. ``help set FOO''
7090 will give a longer description of the variable FOO. ``show'' will show
7091 all of the variable descriptions and their current settings.
7093 confirm on/off: Enables warning questions for operations that are
7094 hard to recover from, e.g. rerunning the program while
7095 it is already running. Default is ON.
7097 editing on/off: Enables EMACS style command line editing
7098 of input. Previous lines can be recalled with
7099 control-P, the current line can be edited with control-B,
7100 you can search for commands with control-R, etc.
7103 history filename NAME: NAME is where the gdb command history
7104 will be stored. The default is .gdb_history,
7105 or the value of the environment variable
7108 history size N: The size, in commands, of the command history. The
7109 default is 256, or the value of the environment variable
7112 history save on/off: If this value is set to ON, the history file will
7113 be saved after exiting gdb. If set to OFF, the
7114 file will not be saved. The default is OFF.
7116 history expansion on/off: If this value is set to ON, then csh-like
7117 history expansion will be performed on
7118 command line input. The default is OFF.
7120 radix N: Sets the default radix for input and output. It can be set
7121 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7122 in the current radix, so "set radix 10" is always a no-op.
7124 height N: This integer value is the number of lines on a page. Default
7125 is 24, the current `stty rows'' setting, or the ``li#''
7126 setting from the termcap entry matching the environment
7129 width N: This integer value is the number of characters on a line.
7130 Default is 80, the current `stty cols'' setting, or the ``co#''
7131 setting from the termcap entry matching the environment
7134 Note: ``set screensize'' is obsolete. Use ``set height'' and
7135 ``set width'' instead.
7137 print address on/off: Print memory addresses in various command displays,
7138 such as stack traces and structure values. Gdb looks
7139 more ``symbolic'' if you turn this off; it looks more
7140 ``machine level'' with it on. Default is ON.
7142 print array on/off: Prettyprint arrays. New convenient format! Default
7145 print demangle on/off: Print C++ symbols in "source" form if on,
7148 print asm-demangle on/off: Same, for assembler level printouts
7151 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7154 * Support for Epoch Environment.
7156 The epoch environment is a version of Emacs v18 with windowing. One
7157 new command, ``inspect'', is identical to ``print'', except that if you
7158 are running in the epoch environment, the value is printed in its own
7162 * Support for Shared Libraries
7164 GDB can now debug programs and core files that use SunOS shared libraries.
7165 Symbols from a shared library cannot be referenced
7166 before the shared library has been linked with the program (this
7167 happens after you type ``run'' and before the function main() is entered).
7168 At any time after this linking (including when examining core files
7169 from dynamically linked programs), gdb reads the symbols from each
7170 shared library when you type the ``sharedlibrary'' command.
7171 It can be abbreviated ``share''.
7173 sharedlibrary REGEXP: Load shared object library symbols for files
7174 matching a unix regular expression. No argument
7175 indicates to load symbols for all shared libraries.
7177 info sharedlibrary: Status of loaded shared libraries.
7182 A watchpoint stops execution of a program whenever the value of an
7183 expression changes. Checking for this slows down execution
7184 tremendously whenever you are in the scope of the expression, but is
7185 quite useful for catching tough ``bit-spreader'' or pointer misuse
7186 problems. Some machines such as the 386 have hardware for doing this
7187 more quickly, and future versions of gdb will use this hardware.
7189 watch EXP: Set a watchpoint (breakpoint) for an expression.
7191 info watchpoints: Information about your watchpoints.
7193 delete N: Deletes watchpoint number N (same as breakpoints).
7194 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7195 enable N: Re-enables watchpoint number N (same as breakpoints).
7198 * C++ multiple inheritance
7200 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7203 * C++ exception handling
7205 Gdb now supports limited C++ exception handling. Besides the existing
7206 ability to breakpoint on an exception handler, gdb can breakpoint on
7207 the raising of an exception (before the stack is peeled back to the
7210 catch FOO: If there is a FOO exception handler in the dynamic scope,
7211 set a breakpoint to catch exceptions which may be raised there.
7212 Multiple exceptions (``catch foo bar baz'') may be caught.
7214 info catch: Lists all exceptions which may be caught in the
7215 current stack frame.
7218 * Minor command changes
7220 The command ``call func (arg, arg, ...)'' now acts like the print
7221 command, except it does not print or save a value if the function's result
7222 is void. This is similar to dbx usage.
7224 The ``up'' and ``down'' commands now always print the frame they end up
7225 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7226 frames without printing.
7228 * New directory command
7230 'dir' now adds directories to the FRONT of the source search path.
7231 The path starts off empty. Source files that contain debug information
7232 about the directory in which they were compiled can be found even
7233 with an empty path; Sun CC and GCC include this information. If GDB can't
7234 find your source file in the current directory, type "dir .".
7236 * Configuring GDB for compilation
7238 For normal use, type ``./configure host''. See README or gdb.texinfo
7241 GDB now handles cross debugging. If you are remotely debugging between
7242 two different machines, type ``./configure host -target=targ''.
7243 Host is the machine where GDB will run; targ is the machine
7244 where the program that you are debugging will run.