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.
56 * Terminal styling is now available for the CLI and the TUI. GNU
57 Source Highlight can additionally be used to provide styling of
58 source code snippets. See the "set style" commands, below, for more
64 GNU/Linux/OpenRISC or1k*-*-linux*
68 set debug compile-cplus-types
69 show debug compile-cplus-types
70 Control the display of debug output about type conversion in the
71 C++ compile feature. Commands have no effect while compiliong
76 Control whether debug output about files/functions skipping is
79 frame apply [all | COUNT | -COUNT | level LEVEL...] [FLAG]... COMMAND
80 Apply a command to some frames.
81 FLAG arguments allow to control what output to produce and how to handle
82 errors raised when applying COMMAND to a frame.
85 Apply a command to all threads (ignoring errors and empty output).
86 Shortcut for 'thread apply all -s COMMAND'.
89 Apply a command to all frames (ignoring errors and empty output).
90 Shortcut for 'frame apply all -s COMMAND'.
93 Apply a command to all frames of all threads (ignoring errors and empty
95 Shortcut for 'thread apply all -s frame apply all -s COMMAND'.
97 maint set dwarf unwinders (on|off)
98 maint show dwarf unwinders
99 Control whether DWARF unwinders can be used.
102 Display a list of open files for a process.
106 target remote FILENAME
107 target extended-remote FILENAME
108 If FILENAME is a Unix domain socket, GDB will attempt to connect
109 to this socket instead of opening FILENAME as a character device.
111 info args [-q] [-t TYPEREGEXP] [NAMEREGEXP]
112 info functions [-q] [-t TYPEREGEXP] [NAMEREGEXP]
113 info locals [-q] [-t TYPEREGEXP] [NAMEREGEXP]
114 info variables [-q] [-t TYPEREGEXP] [NAMEREGEXP]
115 These commands can now print only the searched entities
116 matching the provided regexp(s), giving a condition
117 on the entity names or entity types. The flag -q disables
118 printing headers or informations messages.
124 These commands now determine the syntax for the shown entities
125 according to the language chosen by `set language'. In particular,
126 `set language auto' means to automatically choose the language of
129 thread apply [all | COUNT | -COUNT] [FLAG]... COMMAND
130 The 'thread apply' command accepts new FLAG arguments.
131 FLAG arguments allow to control what output to produce and how to handle
132 errors raised when applying COMMAND to a thread.
134 set tui tab-width NCHARS
135 show tui tab-width NCHARS
136 "set tui tab-width" replaces the "tabset" command, which has been deprecated.
138 set style enabled [on|off]
140 Enable or disable terminal styling. Styling is enabled by default
143 set style filename foreground COLOR
144 set style filename background COLOR
145 set style filename intensity VALUE
146 Control the styling of file names.
148 set style function foreground COLOR
149 set style function background COLOR
150 set style function intensity VALUE
151 Control the styling of function names.
153 set style variable foreground COLOR
154 set style variable background COLOR
155 set style variable intensity VALUE
156 Control the styling of variable names.
158 set style address foreground COLOR
159 set style address background COLOR
160 set style address intensity VALUE
161 Control the styling of addresses.
165 ** The '-data-disassemble' MI command now accepts an '-a' option to
166 disassemble the whole function surrounding the given program
167 counter value or function name. Support for this feature can be
168 verified by using the "-list-features" command, which should
169 contain "data-disassemble-a-option".
171 ** Command responses and notifications that include a frame now include
172 the frame's architecture in a new "arch" attribute.
174 * New native configurations
176 GNU/Linux/RISC-V riscv*-*-linux*
177 FreeBSD/riscv riscv*-*-freebsd*
181 GNU/Linux/RISC-V riscv*-*-linux*
183 CSKY GNU/LINUX csky*-*-linux
184 FreeBSD/riscv riscv*-*-freebsd*
188 ** The gdb.Inferior type has a new 'progspace' property, which is the program
189 space associated to that inferior.
191 ** The gdb.Progspace type has a new 'objfiles' method, which returns the list
192 of objfiles associated to that program space.
194 ** gdb.SYMBOL_LOC_COMMON_BLOCK, gdb.SYMBOL_MODULE_DOMAIN, and
195 gdb.SYMBOL_COMMON_BLOCK_DOMAIN were added to reflect changes to
198 ** gdb.SYMBOL_VARIABLES_DOMAIN, gdb.SYMBOL_FUNCTIONS_DOMAIN, and
199 gdb.SYMBOL_TYPES_DOMAIN are now deprecated. These were never
200 correct and did not work properly.
206 Enable or disable the undefined behavior sanitizer. This is
207 disabled by default, but passing --enable-ubsan=yes or
208 --enable-ubsan=auto to configure will enable it. Enabling this can
209 cause a performance penalty. The undefined behavior sanitizer was
210 first introduced in GCC 4.9.
212 *** Changes in GDB 8.2
214 * The 'set disassembler-options' command now supports specifying options
217 * The 'symbol-file' command now accepts an '-o' option to add a relative
218 offset to all sections.
220 * Similarly, the 'add-symbol-file' command also accepts an '-o' option to add
221 a relative offset to all sections, but it allows to override the load
222 address of individual sections using '-s'.
224 * The 'add-symbol-file' command no longer requires the second argument
225 (address of the text section).
227 * The endianness used with the 'set endian auto' mode in the absence of
228 an executable selected for debugging is now the last endianness chosen
229 either by one of the 'set endian big' and 'set endian little' commands
230 or by inferring from the last executable used, rather than the startup
233 * The pager now allows a "c" response, meaning to disable the pager
234 for the rest of the current command.
236 * The commands 'info variables/functions/types' now show the source line
237 numbers of symbol definitions when available.
239 * 'info proc' now works on running processes on FreeBSD systems and core
240 files created on FreeBSD systems.
242 * C expressions can now use _Alignof, and C++ expressions can now use
245 * Support for SVE on AArch64 Linux. Note that GDB does not detect changes to
246 the vector length while the process is running.
252 Control display of debugging info regarding the FreeBSD native target.
254 set|show varsize-limit
255 This new setting allows the user to control the maximum size of Ada
256 objects being printed when those objects have a variable type,
257 instead of that maximum size being hardcoded to 65536 bytes.
259 set|show record btrace cpu
260 Controls the processor to be used for enabling errata workarounds for
263 maint check libthread-db
264 Run integrity checks on the current inferior's thread debugging
267 maint set check-libthread-db (on|off)
268 maint show check-libthread-db
269 Control whether to run integrity checks on inferior specific thread
270 debugging libraries as they are loaded. The default is not to
275 ** Type alignment is now exposed via the "align" attribute of a gdb.Type.
277 ** The commands attached to a breakpoint can be set by assigning to
278 the breakpoint's "commands" field.
280 ** gdb.execute can now execute multi-line gdb commands.
282 ** The new functions gdb.convenience_variable and
283 gdb.set_convenience_variable can be used to get and set the value
284 of convenience variables.
286 ** A gdb.Parameter will no longer print the "set" help text on an
287 ordinary "set"; instead by default a "set" will be silent unless
288 the get_set_string method returns a non-empty string.
292 RiscV ELF riscv*-*-elf
294 * Removed targets and native configurations
296 m88k running OpenBSD m88*-*-openbsd*
297 SH-5/SH64 ELF sh64-*-elf*, SH-5/SH64 support in sh*
298 SH-5/SH64 running GNU/Linux SH-5/SH64 support in sh*-*-linux*
299 SH-5/SH64 running OpenBSD SH-5/SH64 support in sh*-*-openbsd*
301 * Aarch64/Linux hardware watchpoints improvements
303 Hardware watchpoints on unaligned addresses are now properly
304 supported when running Linux kernel 4.10 or higher: read and access
305 watchpoints are no longer spuriously missed, and all watchpoints
306 lengths between 1 and 8 bytes are supported. On older kernels,
307 watchpoints set on unaligned addresses are no longer missed, with
308 the tradeoff that there is a possibility of false hits being
313 --enable-codesign=CERT
314 This can be used to invoke "codesign -s CERT" after building gdb.
315 This option is useful on macOS, where code signing is required for
316 gdb to work properly.
318 --disable-gdbcli has been removed
319 This is now silently accepted, but does nothing.
321 *** Changes in GDB 8.1
323 * GDB now supports dynamically creating arbitrary register groups specified
324 in XML target descriptions. This allows for finer grain grouping of
325 registers on systems with a large amount of registers.
327 * The 'ptype' command now accepts a '/o' flag, which prints the
328 offsets and sizes of fields in a struct, like the pahole(1) tool.
330 * New "--readnever" command line option instructs GDB to not read each
331 symbol file's symbolic debug information. This makes startup faster
332 but at the expense of not being able to perform symbolic debugging.
333 This option is intended for use cases where symbolic debugging will
334 not be used, e.g., when you only need to dump the debuggee's core.
336 * GDB now uses the GNU MPFR library, if available, to emulate target
337 floating-point arithmetic during expression evaluation when the target
338 uses different floating-point formats than the host. At least version
339 3.1 of GNU MPFR is required.
341 * GDB now supports access to the guarded-storage-control registers and the
342 software-based guarded-storage broadcast control registers on IBM z14.
344 * On Unix systems, GDB now supports transmitting environment variables
345 that are to be set or unset to GDBserver. These variables will
346 affect the environment to be passed to the remote inferior.
348 To inform GDB of environment variables that are to be transmitted to
349 GDBserver, use the "set environment" command. Only user set
350 environment variables are sent to GDBserver.
352 To inform GDB of environment variables that are to be unset before
353 the remote inferior is started by the GDBserver, use the "unset
354 environment" command.
356 * Completion improvements
358 ** GDB can now complete function parameters in linespecs and
359 explicit locations without quoting. When setting breakpoints,
360 quoting around functions names to help with TAB-completion is
361 generally no longer necessary. For example, this now completes
364 (gdb) b function(in[TAB]
365 (gdb) b function(int)
367 Related, GDB is no longer confused with completing functions in
368 C++ anonymous namespaces:
371 (gdb) b (anonymous namespace)::[TAB][TAB]
372 (anonymous namespace)::a_function()
373 (anonymous namespace)::b_function()
375 ** GDB now has much improved linespec and explicit locations TAB
376 completion support, that better understands what you're
377 completing and offers better suggestions. For example, GDB no
378 longer offers data symbols as possible completions when you're
379 setting a breakpoint.
381 ** GDB now TAB-completes label symbol names.
383 ** The "complete" command now mimics TAB completion accurately.
385 * New command line options (gcore)
388 Dump all memory mappings.
390 * Breakpoints on C++ functions are now set on all scopes by default
392 By default, breakpoints on functions/methods are now interpreted as
393 specifying all functions with the given name ignoring missing
394 leading scopes (namespaces and classes).
396 For example, assuming a C++ program with symbols named:
401 both commands "break func()" and "break B::func()" set a breakpoint
404 You can use the new flag "-qualified" to override this. This makes
405 GDB interpret the specified function name as a complete
406 fully-qualified name instead. For example, using the same C++
407 program, the "break -q B::func" command sets a breakpoint on
408 "B::func", only. A parameter has been added to the Python
409 gdb.Breakpoint constructor to achieve the same result when creating
410 a breakpoint from Python.
412 * Breakpoints on functions marked with C++ ABI tags
414 GDB can now set breakpoints on functions marked with C++ ABI tags
415 (e.g., [abi:cxx11]). See here for a description of ABI tags:
416 https://developers.redhat.com/blog/2015/02/05/gcc5-and-the-c11-abi/
418 Functions with a C++11 abi tag are demangled/displayed like this:
420 function[abi:cxx11](int)
423 You can now set a breakpoint on such functions simply as if they had
426 (gdb) b function(int)
428 Or if you need to disambiguate between tags, like:
430 (gdb) b function[abi:other_tag](int)
432 Tab completion was adjusted accordingly as well.
436 ** New events gdb.new_inferior, gdb.inferior_deleted, and
437 gdb.new_thread are emitted. See the manual for further
438 description of these.
440 ** A new function, "gdb.rbreak" has been added to the Python API.
441 This function allows the setting of a large number of breakpoints
442 via a regex pattern in Python. See the manual for further details.
444 ** Python breakpoints can now accept explicit locations. See the
445 manual for a further description of this feature.
448 * New features in the GDB remote stub, GDBserver
450 ** GDBserver is now able to start inferior processes with a
451 specified initial working directory.
453 The user can set the desired working directory to be used from
454 GDB using the new "set cwd" command.
456 ** New "--selftest" command line option runs some GDBserver self
457 tests. These self tests are disabled in releases.
459 ** On Unix systems, GDBserver now does globbing expansion and variable
460 substitution in inferior command line arguments.
462 This is done by starting inferiors using a shell, like GDB does.
463 See "set startup-with-shell" in the user manual for how to disable
464 this from GDB when using "target extended-remote". When using
465 "target remote", you can disable the startup with shell by using the
466 new "--no-startup-with-shell" GDBserver command line option.
468 ** On Unix systems, GDBserver now supports receiving environment
469 variables that are to be set or unset from GDB. These variables
470 will affect the environment to be passed to the inferior.
472 * When catching an Ada exception raised with a message, GDB now prints
473 the message in the catchpoint hit notification. In GDB/MI mode, that
474 information is provided as an extra field named "exception-message"
475 in the *stopped notification.
477 * Trait objects can now be inspected When debugging Rust code. This
478 requires compiler support which will appear in Rust 1.24.
482 QEnvironmentHexEncoded
483 Inform GDBserver of an environment variable that is to be passed to
484 the inferior when starting it.
487 Inform GDBserver of an environment variable that is to be unset
488 before starting the remote inferior.
491 Inform GDBserver that the environment should be reset (i.e.,
492 user-set environment variables should be unset).
495 Indicates whether the inferior must be started with a shell or not.
498 Tell GDBserver that the inferior to be started should use a specific
501 * The "maintenance print c-tdesc" command now takes an optional
502 argument which is the file name of XML target description.
504 * The "maintenance selftest" command now takes an optional argument to
505 filter the tests to be run.
507 * The "enable", and "disable" commands now accept a range of
508 breakpoint locations, e.g. "enable 1.3-5".
513 Set and show the current working directory for the inferior.
516 Set and show compilation command used for compiling and injecting code
517 with the 'compile' commands.
519 set debug separate-debug-file
520 show debug separate-debug-file
521 Control the display of debug output about separate debug file search.
523 set dump-excluded-mappings
524 show dump-excluded-mappings
525 Control whether mappings marked with the VM_DONTDUMP flag should be
526 dumped when generating a core file.
529 List the registered selftests.
532 Start the debugged program stopping at the first instruction.
535 Control display of debugging messages related to OpenRISC targets.
537 set|show print type nested-type-limit
538 Set and show the limit of nesting level for nested types that the
539 type printer will show.
541 * TUI Single-Key mode now supports two new shortcut keys: `i' for stepi and
544 * Safer/improved support for debugging with no debug info
546 GDB no longer assumes functions with no debug information return
549 This means that GDB now refuses to call such functions unless you
550 tell it the function's type, by either casting the call to the
551 declared return type, or by casting the function to a function
552 pointer of the right type, and calling that:
554 (gdb) p getenv ("PATH")
555 'getenv' has unknown return type; cast the call to its declared return type
556 (gdb) p (char *) getenv ("PATH")
557 $1 = 0x7fffffffe "/usr/local/bin:/"...
558 (gdb) p ((char * (*) (const char *)) getenv) ("PATH")
559 $2 = 0x7fffffffe "/usr/local/bin:/"...
561 Similarly, GDB no longer assumes that global variables with no debug
562 info have type 'int', and refuses to print the variable's value
563 unless you tell it the variable's type:
566 'var' has unknown type; cast it to its declared type
570 * New native configurations
572 FreeBSD/aarch64 aarch64*-*-freebsd*
573 FreeBSD/arm arm*-*-freebsd*
577 FreeBSD/aarch64 aarch64*-*-freebsd*
578 FreeBSD/arm arm*-*-freebsd*
579 OpenRISC ELF or1k*-*-elf
581 * Removed targets and native configurations
583 Solaris 2.0-9 i?86-*-solaris2.[0-9], sparc*-*-solaris2.[0-9]
585 *** Changes in GDB 8.0
587 * GDB now supports access to the PKU register on GNU/Linux. The register is
588 added by the Memory Protection Keys for Userspace feature which will be
589 available in future Intel CPUs.
591 * GDB now supports C++11 rvalue references.
595 ** New functions to start, stop and access a running btrace recording.
596 ** Rvalue references are now supported in gdb.Type.
598 * GDB now supports recording and replaying rdrand and rdseed Intel 64
601 * Building GDB and GDBserver now requires a C++11 compiler.
603 For example, GCC 4.8 or later.
605 It is no longer possible to build GDB or GDBserver with a C
606 compiler. The --disable-build-with-cxx configure option has been
609 * Building GDB and GDBserver now requires GNU make >= 3.81.
611 It is no longer supported to build GDB or GDBserver with another
612 implementation of the make program or an earlier version of GNU make.
614 * Native debugging on MS-Windows supports command-line redirection
616 Command-line arguments used for starting programs on MS-Windows can
617 now include redirection symbols supported by native Windows shells,
618 such as '<', '>', '>>', '2>&1', etc. This affects GDB commands such
619 as "run", "start", and "set args", as well as the corresponding MI
622 * Support for thread names on MS-Windows.
624 GDB now catches and handles the special exception that programs
625 running on MS-Windows use to assign names to threads in the
628 * Support for Java programs compiled with gcj has been removed.
630 * User commands now accept an unlimited number of arguments.
631 Previously, only up to 10 was accepted.
633 * The "eval" command now expands user-defined command arguments.
635 This makes it easier to process a variable number of arguments:
640 eval "print $arg%d", $i
645 * Target descriptions can now describe registers for sparc32 and sparc64.
647 * GDB now supports DWARF version 5 (debug information format).
648 Its .debug_names index is not yet supported.
650 * New native configurations
652 FreeBSD/mips mips*-*-freebsd
656 Synopsys ARC arc*-*-elf32
657 FreeBSD/mips mips*-*-freebsd
659 * Removed targets and native configurations
661 Alpha running FreeBSD alpha*-*-freebsd*
662 Alpha running GNU/kFreeBSD alpha*-*-kfreebsd*-gnu
667 Erases all the flash memory regions reported by the target.
669 maint print arc arc-instruction address
670 Print internal disassembler information about instruction at a given address.
674 set disassembler-options
675 show disassembler-options
676 Controls the passing of target specific information to the disassembler.
677 If it is necessary to specify more than one disassembler option then
678 multiple options can be placed together into a comma separated list.
679 The default value is the empty string. Currently, the only supported
680 targets are ARM, PowerPC and S/390.
685 Erases all the flash memory regions reported by the target. This is
686 equivalent to the CLI command flash-erase.
688 -file-list-shared-libraries
689 List the shared libraries in the program. This is
690 equivalent to the CLI command "info shared".
693 Catchpoints stopping the program when Ada exceptions are
694 handled. This is equivalent to the CLI command "catch handlers".
696 *** Changes in GDB 7.12
698 * GDB and GDBserver now build with a C++ compiler by default.
700 The --enable-build-with-cxx configure option is now enabled by
701 default. One must now explicitly configure with
702 --disable-build-with-cxx in order to build with a C compiler. This
703 option will be removed in a future release.
705 * GDBserver now supports recording btrace without maintaining an active
708 * GDB now supports a negative repeat count in the 'x' command to examine
709 memory backward from the given address. For example:
712 #0 Func1 (n=42, p=0x40061c "hogehoge") at main.cpp:4
713 #1 0x400580 in main (argc=1, argv=0x7fffffffe5c8) at main.cpp:8
714 (gdb) x/-5i 0x0000000000400580
715 0x40056a <main(int, char**)+8>: mov %edi,-0x4(%rbp)
716 0x40056d <main(int, char**)+11>: mov %rsi,-0x10(%rbp)
717 0x400571 <main(int, char**)+15>: mov $0x40061c,%esi
718 0x400576 <main(int, char**)+20>: mov $0x2a,%edi
719 0x40057b <main(int, char**)+25>:
720 callq 0x400536 <Func1(int, char const*)>
722 * Fortran: Support structures with fields of dynamic types and
723 arrays of dynamic types.
725 * The symbol dumping maintenance commands have new syntax.
726 maint print symbols [-pc address] [--] [filename]
727 maint print symbols [-objfile objfile] [-source source] [--] [filename]
728 maint print psymbols [-objfile objfile] [-pc address] [--] [filename]
729 maint print psymbols [-objfile objfile] [-source source] [--] [filename]
730 maint print msymbols [-objfile objfile] [--] [filename]
732 * GDB now supports multibit bitfields and enums in target register
735 * New Python-based convenience function $_as_string(val), which returns
736 the textual representation of a value. This function is especially
737 useful to obtain the text label of an enum value.
739 * Intel MPX bound violation handling.
741 Segmentation faults caused by a Intel MPX boundary violation
742 now display the kind of violation (upper or lower), the memory
743 address accessed and the memory bounds, along with the usual
744 signal received and code location.
748 Program received signal SIGSEGV, Segmentation fault
749 Upper bound violation while accessing address 0x7fffffffc3b3
750 Bounds: [lower = 0x7fffffffc390, upper = 0x7fffffffc3a3]
751 0x0000000000400d7c in upper () at i386-mpx-sigsegv.c:68
753 * Rust language support.
754 GDB now supports debugging programs written in the Rust programming
755 language. See https://www.rust-lang.org/ for more information about
758 * Support for running interpreters on specified input/output devices
760 GDB now supports a new mechanism that allows frontends to provide
761 fully featured GDB console views, as a better alternative to
762 building such views on top of the "-interpreter-exec console"
763 command. See the new "new-ui" command below. With that command,
764 frontends can now start GDB in the traditional command-line mode
765 running in an embedded terminal emulator widget, and create a
766 separate MI interpreter running on a specified i/o device. In this
767 way, GDB handles line editing, history, tab completion, etc. in the
768 console all by itself, and the GUI uses the separate MI interpreter
769 for its own control and synchronization, invisible to the command
772 * The "catch syscall" command catches groups of related syscalls.
774 The "catch syscall" command now supports catching a group of related
775 syscalls using the 'group:' or 'g:' prefix.
780 skip -gfile file-glob-pattern
781 skip -function function
782 skip -rfunction regular-expression
783 A generalized form of the skip command, with new support for
784 glob-style file names and regular expressions for function names.
785 Additionally, a file spec and a function spec may now be combined.
787 maint info line-table REGEXP
788 Display the contents of GDB's internal line table data struture.
791 Run any GDB unit tests that were compiled in.
794 Start a new user interface instance running INTERP as interpreter,
795 using the TTY file for input/output.
799 ** gdb.Breakpoint objects have a new attribute "pending", which
800 indicates whether the breakpoint is pending.
801 ** Three new breakpoint-related events have been added:
802 gdb.breakpoint_created, gdb.breakpoint_modified, and
803 gdb.breakpoint_deleted.
806 Signal ("set") the given MS-Windows event object. This is used in
807 conjunction with the Windows JIT debugging (AeDebug) support, where
808 the OS suspends a crashing process until a debugger can attach to
809 it. Resuming the crashing process, in order to debug it, is done by
812 * Support for tracepoints and fast tracepoints on s390-linux and s390x-linux
813 was added in GDBserver, including JIT compiling fast tracepoint's
814 conditional expression bytecode into native code.
816 * Support for various remote target protocols and ROM monitors has
819 target m32rsdi Remote M32R debugging over SDI
820 target mips MIPS remote debugging protocol
821 target pmon PMON ROM monitor
822 target ddb NEC's DDB variant of PMON for Vr4300
823 target rockhopper NEC RockHopper variant of PMON
824 target lsi LSI variant of PMO
826 * Support for tracepoints and fast tracepoints on powerpc-linux,
827 powerpc64-linux, and powerpc64le-linux was added in GDBserver,
828 including JIT compiling fast tracepoint's conditional expression
829 bytecode into native code.
831 * MI async record =record-started now includes the method and format used for
832 recording. For example:
834 =record-started,thread-group="i1",method="btrace",format="bts"
836 * MI async record =thread-selected now includes the frame field. For example:
838 =thread-selected,id="3",frame={level="0",addr="0x00000000004007c0"}
842 Andes NDS32 nds32*-*-elf
844 *** Changes in GDB 7.11
846 * GDB now supports debugging kernel-based threads on FreeBSD.
848 * Per-inferior thread numbers
850 Thread numbers are now per inferior instead of global. If you're
851 debugging multiple inferiors, GDB displays thread IDs using a
852 qualified INF_NUM.THR_NUM form. For example:
856 1.1 Thread 0x7ffff7fc2740 (LWP 8155) (running)
857 1.2 Thread 0x7ffff7fc1700 (LWP 8168) (running)
858 * 2.1 Thread 0x7ffff7fc2740 (LWP 8157) (running)
859 2.2 Thread 0x7ffff7fc1700 (LWP 8190) (running)
861 As consequence, thread numbers as visible in the $_thread
862 convenience variable and in Python's InferiorThread.num attribute
863 are no longer unique between inferiors.
865 GDB now maintains a second thread ID per thread, referred to as the
866 global thread ID, which is the new equivalent of thread numbers in
867 previous releases. See also $_gthread below.
869 For backwards compatibility, MI's thread IDs always refer to global
872 * Commands that accept thread IDs now accept the qualified
873 INF_NUM.THR_NUM form as well. For example:
876 [Switching to thread 2.1 (Thread 0x7ffff7fc2740 (LWP 8157))] (running)
879 * In commands that accept a list of thread IDs, you can now refer to
880 all threads of an inferior using a star wildcard. GDB accepts
881 "INF_NUM.*", to refer to all threads of inferior INF_NUM, and "*" to
882 refer to all threads of the current inferior. For example, "info
885 * You can use "info threads -gid" to display the global thread ID of
888 * The new convenience variable $_gthread holds the global number of
891 * The new convenience variable $_inferior holds the number of the
894 * GDB now displays the ID and name of the thread that hit a breakpoint
895 or received a signal, if your program is multi-threaded. For
898 Thread 3 "bar" hit Breakpoint 1 at 0x40087a: file program.c, line 20.
899 Thread 1 "main" received signal SIGINT, Interrupt.
901 * Record btrace now supports non-stop mode.
903 * Support for tracepoints on aarch64-linux was added in GDBserver.
905 * The 'record instruction-history' command now indicates speculative execution
906 when using the Intel Processor Trace recording format.
908 * GDB now allows users to specify explicit locations, bypassing
909 the linespec parser. This feature is also available to GDB/MI
912 * Multi-architecture debugging is supported on AArch64 GNU/Linux.
913 GDB now is able to debug both AArch64 applications and ARM applications
916 * Support for fast tracepoints on aarch64-linux was added in GDBserver,
917 including JIT compiling fast tracepoint's conditional expression bytecode
920 * GDB now supports displaced stepping on AArch64 GNU/Linux.
922 * "info threads", "info inferiors", "info display", "info checkpoints"
923 and "maint info program-spaces" now list the corresponding items in
924 ascending ID order, for consistency with all other "info" commands.
926 * In Ada, the overloads selection menu has been enhanced to display the
927 parameter types and the return types for the matching overloaded subprograms.
931 maint set target-non-stop (on|off|auto)
932 maint show target-non-stop
933 Control whether GDB targets always operate in non-stop mode even if
934 "set non-stop" is "off". The default is "auto", meaning non-stop
935 mode is enabled if supported by the target.
937 maint set bfd-sharing
938 maint show bfd-sharing
939 Control the reuse of bfd objects.
943 Control display of debugging info regarding bfd caching.
947 Control display of debugging info regarding FreeBSD threads.
949 set remote multiprocess-extensions-packet
950 show remote multiprocess-extensions-packet
951 Set/show the use of the remote protocol multiprocess extensions.
953 set remote thread-events
954 show remote thread-events
955 Set/show the use of thread create/exit events.
957 set ada print-signatures on|off
958 show ada print-signatures"
959 Control whether parameter types and return types are displayed in overloads
960 selection menus. It is activaled (@code{on}) by default.
964 Controls the maximum size of memory, in bytes, that GDB will
965 allocate for value contents. Prevents incorrect programs from
966 causing GDB to allocate overly large buffers. Default is 64k.
968 * The "disassemble" command accepts a new modifier: /s.
969 It prints mixed source+disassembly like /m with two differences:
970 - disassembled instructions are now printed in program order, and
971 - and source for all relevant files is now printed.
972 The "/m" option is now considered deprecated: its "source-centric"
973 output hasn't proved useful in practice.
975 * The "record instruction-history" command accepts a new modifier: /s.
976 It behaves exactly like /m and prints mixed source+disassembly.
978 * The "set scheduler-locking" command supports a new mode "replay".
979 It behaves like "off" in record mode and like "on" in replay mode.
981 * Support for various ROM monitors has been removed:
983 target dbug dBUG ROM monitor for Motorola ColdFire
984 target picobug Motorola picobug monitor
985 target dink32 DINK32 ROM monitor for PowerPC
986 target m32r Renesas M32R/D ROM monitor
987 target mon2000 mon2000 ROM monitor
988 target ppcbug PPCBUG ROM monitor for PowerPC
990 * Support for reading/writing memory and extracting values on architectures
991 whose memory is addressable in units of any integral multiple of 8 bits.
994 Allows to break when an Ada exception is handled.
999 Indicates that an exec system call was executed.
1001 exec-events feature in qSupported
1002 The qSupported packet allows GDB to request support for exec
1003 events using the new 'gdbfeature' exec-event, and the qSupported
1004 response can contain the corresponding 'stubfeature'. Set and
1005 show commands can be used to display whether these features are enabled.
1008 Equivalent to interrupting with the ^C character, but works in
1011 thread created stop reason (T05 create:...)
1012 Indicates that the thread was just created and is stopped at entry.
1014 thread exit stop reply (w exitcode;tid)
1015 Indicates that the thread has terminated.
1018 Enables/disables thread create and exit event reporting. For
1019 example, this is used in non-stop mode when GDB stops a set of
1020 threads and synchronously waits for the their corresponding stop
1021 replies. Without exit events, if one of the threads exits, GDB
1022 would hang forever not knowing that it should no longer expect a
1023 stop for that same thread.
1026 Indicates that there are no resumed threads left in the target (all
1027 threads are stopped). The remote stub reports support for this stop
1028 reply to GDB's qSupported query.
1031 Enables/disables catching syscalls from the inferior process.
1032 The remote stub reports support for this packet to GDB's qSupported query.
1034 syscall_entry stop reason
1035 Indicates that a syscall was just called.
1037 syscall_return stop reason
1038 Indicates that a syscall just returned.
1040 * Extended-remote exec events
1042 ** GDB now has support for exec events on extended-remote Linux targets.
1043 For such targets with Linux kernels 2.5.46 and later, this enables
1044 follow-exec-mode and exec catchpoints.
1046 set remote exec-event-feature-packet
1047 show remote exec-event-feature-packet
1048 Set/show the use of the remote exec event feature.
1050 * Thread names in remote protocol
1052 The reply to qXfer:threads:read may now include a name attribute for each
1055 * Target remote mode fork and exec events
1057 ** GDB now has support for fork and exec events on target remote mode
1058 Linux targets. For such targets with Linux kernels 2.5.46 and later,
1059 this enables follow-fork-mode, detach-on-fork, follow-exec-mode, and
1060 fork and exec catchpoints.
1062 * Remote syscall events
1064 ** GDB now has support for catch syscall on remote Linux targets,
1065 currently enabled on x86/x86_64 architectures.
1067 set remote catch-syscall-packet
1068 show remote catch-syscall-packet
1069 Set/show the use of the remote catch syscall feature.
1073 ** The -var-set-format command now accepts the zero-hexadecimal
1074 format. It outputs data in hexadecimal format with zero-padding on the
1079 ** gdb.InferiorThread objects have a new attribute "global_num",
1080 which refers to the thread's global thread ID. The existing
1081 "num" attribute now refers to the thread's per-inferior number.
1082 See "Per-inferior thread numbers" above.
1083 ** gdb.InferiorThread objects have a new attribute "inferior", which
1084 is the Inferior object the thread belongs to.
1086 *** Changes in GDB 7.10
1088 * Support for process record-replay and reverse debugging on aarch64*-linux*
1089 targets has been added. GDB now supports recording of A64 instruction set
1090 including advance SIMD instructions.
1092 * Support for Sun's version of the "stabs" debug file format has been removed.
1094 * GDB now honors the content of the file /proc/PID/coredump_filter
1095 (PID is the process ID) on GNU/Linux systems. This file can be used
1096 to specify the types of memory mappings that will be included in a
1097 corefile. For more information, please refer to the manual page of
1098 "core(5)". GDB also has a new command: "set use-coredump-filter
1099 on|off". It allows to set whether GDB will read the content of the
1100 /proc/PID/coredump_filter file when generating a corefile.
1102 * The "info os" command on GNU/Linux can now display information on
1104 "info os cpus" Listing of all cpus/cores on the system
1106 * GDB has two new commands: "set serial parity odd|even|none" and
1107 "show serial parity". These allows to set or show parity for the
1110 * The "info source" command now displays the producer string if it was
1111 present in the debug info. This typically includes the compiler version
1112 and may include things like its command line arguments.
1114 * The "info dll", an alias of the "info sharedlibrary" command,
1115 is now available on all platforms.
1117 * Directory names supplied to the "set sysroot" commands may be
1118 prefixed with "target:" to tell GDB to access shared libraries from
1119 the target system, be it local or remote. This replaces the prefix
1120 "remote:". The default sysroot has been changed from "" to
1121 "target:". "remote:" is automatically converted to "target:" for
1122 backward compatibility.
1124 * The system root specified by "set sysroot" will be prepended to the
1125 filename of the main executable (if reported to GDB as absolute by
1126 the operating system) when starting processes remotely, and when
1127 attaching to already-running local or remote processes.
1129 * GDB now supports automatic location and retrieval of executable
1130 files from remote targets. Remote debugging can now be initiated
1131 using only a "target remote" or "target extended-remote" command
1132 (no "set sysroot" or "file" commands are required). See "New remote
1135 * The "dump" command now supports verilog hex format.
1137 * GDB now supports the vector ABI on S/390 GNU/Linux targets.
1139 * On GNU/Linux, GDB and gdbserver are now able to access executable
1140 and shared library files without a "set sysroot" command when
1141 attaching to processes running in different mount namespaces from
1142 the debugger. This makes it possible to attach to processes in
1143 containers as simply as "gdb -p PID" or "gdbserver --attach PID".
1144 See "New remote packets" below.
1146 * The "tui reg" command now provides completion for all of the
1147 available register groups, including target specific groups.
1149 * The HISTSIZE environment variable is no longer read when determining
1150 the size of GDB's command history. GDB now instead reads the dedicated
1151 GDBHISTSIZE environment variable. Setting GDBHISTSIZE to "-1" or to "" now
1152 disables truncation of command history. Non-numeric values of GDBHISTSIZE
1157 ** Memory ports can now be unbuffered.
1161 ** gdb.Objfile objects have a new attribute "username",
1162 which is the name of the objfile as specified by the user,
1163 without, for example, resolving symlinks.
1164 ** You can now write frame unwinders in Python.
1165 ** gdb.Type objects have a new method "optimized_out",
1166 returning optimized out gdb.Value instance of this type.
1167 ** gdb.Value objects have new methods "reference_value" and
1168 "const_value" which return a reference to the value and a
1169 "const" version of the value respectively.
1173 maint print symbol-cache
1174 Print the contents of the symbol cache.
1176 maint print symbol-cache-statistics
1177 Print statistics of symbol cache usage.
1179 maint flush-symbol-cache
1180 Flush the contents of the symbol cache.
1184 Start branch trace recording using Branch Trace Store (BTS) format.
1187 Evaluate expression by using the compiler and print result.
1191 Explicit commands for enabling and disabling tui mode.
1194 set mpx bound on i386 and amd64
1195 Support for bound table investigation on Intel MPX enabled applications.
1199 Start branch trace recording using Intel Processor Trace format.
1202 Print information about branch tracing internals.
1204 maint btrace packet-history
1205 Print the raw branch tracing data.
1207 maint btrace clear-packet-history
1208 Discard the stored raw branch tracing data.
1211 Discard all branch tracing data. It will be fetched and processed
1212 anew by the next "record" command.
1217 Renamed from "set debug dwarf2-die".
1218 show debug dwarf-die
1219 Renamed from "show debug dwarf2-die".
1221 set debug dwarf-read
1222 Renamed from "set debug dwarf2-read".
1223 show debug dwarf-read
1224 Renamed from "show debug dwarf2-read".
1226 maint set dwarf always-disassemble
1227 Renamed from "maint set dwarf2 always-disassemble".
1228 maint show dwarf always-disassemble
1229 Renamed from "maint show dwarf2 always-disassemble".
1231 maint set dwarf max-cache-age
1232 Renamed from "maint set dwarf2 max-cache-age".
1233 maint show dwarf max-cache-age
1234 Renamed from "maint show dwarf2 max-cache-age".
1236 set debug dwarf-line
1237 show debug dwarf-line
1238 Control display of debugging info regarding DWARF line processing.
1241 show max-completions
1242 Set the maximum number of candidates to be considered during
1243 completion. The default value is 200. This limit allows GDB
1244 to avoid generating large completion lists, the computation of
1245 which can cause the debugger to become temporarily unresponsive.
1247 set history remove-duplicates
1248 show history remove-duplicates
1249 Control the removal of duplicate history entries.
1251 maint set symbol-cache-size
1252 maint show symbol-cache-size
1253 Control the size of the symbol cache.
1255 set|show record btrace bts buffer-size
1256 Set and show the size of the ring buffer used for branch tracing in
1258 The obtained size may differ from the requested size. Use "info
1259 record" to see the obtained buffer size.
1261 set debug linux-namespaces
1262 show debug linux-namespaces
1263 Control display of debugging info regarding Linux namespaces.
1265 set|show record btrace pt buffer-size
1266 Set and show the size of the ring buffer used for branch tracing in
1267 Intel Processor Trace format.
1268 The obtained size may differ from the requested size. Use "info
1269 record" to see the obtained buffer size.
1271 maint set|show btrace pt skip-pad
1272 Set and show whether PAD packets are skipped when computing the
1275 * The command 'thread apply all' can now support new option '-ascending'
1276 to call its specified command for all threads in ascending order.
1278 * Python/Guile scripting
1280 ** GDB now supports auto-loading of Python/Guile scripts contained in the
1281 special section named `.debug_gdb_scripts'.
1283 * New remote packets
1285 qXfer:btrace-conf:read
1286 Return the branch trace configuration for the current thread.
1288 Qbtrace-conf:bts:size
1289 Set the requested ring buffer size for branch tracing in BTS format.
1292 Enable Intel Procesor Trace-based branch tracing for the current
1293 process. The remote stub reports support for this packet to GDB's
1296 Qbtrace-conf:pt:size
1297 Set the requested ring buffer size for branch tracing in Intel Processor
1301 Indicates a memory breakpoint instruction was executed, irrespective
1302 of whether it was GDB that planted the breakpoint or the breakpoint
1303 is hardcoded in the program. This is required for correct non-stop
1307 Indicates the target stopped for a hardware breakpoint. This is
1308 required for correct non-stop mode operation.
1311 Return information about files on the remote system.
1313 qXfer:exec-file:read
1314 Return the full absolute name of the file that was executed to
1315 create a process running on the remote system.
1318 Select the filesystem on which vFile: operations with filename
1319 arguments will operate. This is required for GDB to be able to
1320 access files on remote targets where the remote stub does not
1321 share a common filesystem with the inferior(s).
1324 Indicates that a fork system call was executed.
1327 Indicates that a vfork system call was executed.
1329 vforkdone stop reason
1330 Indicates that a vfork child of the specified process has executed
1331 an exec or exit, allowing the vfork parent to resume execution.
1333 fork-events and vfork-events features in qSupported
1334 The qSupported packet allows GDB to request support for fork and
1335 vfork events using new 'gdbfeatures' fork-events and vfork-events,
1336 and the qSupported response can contain the corresponding
1337 'stubfeatures'. Set and show commands can be used to display
1338 whether these features are enabled.
1340 * Extended-remote fork events
1342 ** GDB now has support for fork events on extended-remote Linux
1343 targets. For targets with Linux kernels 2.5.60 and later, this
1344 enables follow-fork-mode and detach-on-fork for both fork and
1345 vfork, as well as fork and vfork catchpoints.
1347 * The info record command now shows the recording format and the
1348 branch tracing configuration for the current thread when using
1349 the btrace record target.
1350 For the BTS format, it shows the ring buffer size.
1352 * GDB now has support for DTrace USDT (Userland Static Defined
1353 Tracing) probes. The supported targets are x86_64-*-linux-gnu.
1355 * GDB now supports access to vector registers on S/390 GNU/Linux
1358 * Removed command line options
1360 -xdb HP-UX XDB compatibility mode.
1362 * Removed targets and native configurations
1364 HP/PA running HP-UX hppa*-*-hpux*
1365 Itanium running HP-UX ia64-*-hpux*
1367 * New configure options
1370 This configure option allows the user to build GDB with support for
1371 Intel Processor Trace (default: auto). This requires libipt.
1373 --with-libipt-prefix=PATH
1374 Specify the path to the version of libipt that GDB should use.
1375 $PATH/include should contain the intel-pt.h header and
1376 $PATH/lib should contain the libipt.so library.
1378 *** Changes in GDB 7.9.1
1382 ** Xmethods can now specify a result type.
1384 *** Changes in GDB 7.9
1386 * GDB now supports hardware watchpoints on x86 GNU Hurd.
1390 ** You can now access frame registers from Python scripts.
1391 ** New attribute 'producer' for gdb.Symtab objects.
1392 ** gdb.Objfile objects have a new attribute "progspace",
1393 which is the gdb.Progspace object of the containing program space.
1394 ** gdb.Objfile objects have a new attribute "owner".
1395 ** gdb.Objfile objects have a new attribute "build_id",
1396 which is the build ID generated when the file was built.
1397 ** gdb.Objfile objects have a new method "add_separate_debug_file".
1398 ** A new event "gdb.clear_objfiles" has been added, triggered when
1399 selecting a new file to debug.
1400 ** You can now add attributes to gdb.Objfile and gdb.Progspace objects.
1401 ** New function gdb.lookup_objfile.
1403 New events which are triggered when GDB modifies the state of the
1406 ** gdb.events.inferior_call_pre: Function call is about to be made.
1407 ** gdb.events.inferior_call_post: Function call has just been made.
1408 ** gdb.events.memory_changed: A memory location has been altered.
1409 ** gdb.events.register_changed: A register has been altered.
1411 * New Python-based convenience functions:
1413 ** $_caller_is(name [, number_of_frames])
1414 ** $_caller_matches(regexp [, number_of_frames])
1415 ** $_any_caller_is(name [, number_of_frames])
1416 ** $_any_caller_matches(regexp [, number_of_frames])
1418 * GDB now supports the compilation and injection of source code into
1419 the inferior. GDB will use GCC 5.0 or higher built with libcc1.so
1420 to compile the source code to object code, and if successful, inject
1421 and execute that code within the current context of the inferior.
1422 Currently the C language is supported. The commands used to
1423 interface with this new feature are:
1425 compile code [-raw|-r] [--] [source code]
1426 compile file [-raw|-r] filename
1430 demangle [-l language] [--] name
1431 Demangle "name" in the specified language, or the current language
1432 if elided. This command is renamed from the "maint demangle" command.
1433 The latter is kept as a no-op to avoid "maint demangle" being interpreted
1434 as "maint demangler-warning".
1436 queue-signal signal-name-or-number
1437 Queue a signal to be delivered to the thread when it is resumed.
1439 add-auto-load-scripts-directory directory
1440 Add entries to the list of directories from which to load auto-loaded
1443 maint print user-registers
1444 List all currently available "user" registers.
1446 compile code [-r|-raw] [--] [source code]
1447 Compile, inject, and execute in the inferior the executable object
1448 code produced by compiling the provided source code.
1450 compile file [-r|-raw] filename
1451 Compile and inject into the inferior the executable object code
1452 produced by compiling the source code stored in the filename
1455 * On resume, GDB now always passes the signal the program had stopped
1456 for to the thread the signal was sent to, even if the user changed
1457 threads before resuming. Previously GDB would often (but not
1458 always) deliver the signal to the thread that happens to be current
1461 * Conversely, the "signal" command now consistently delivers the
1462 requested signal to the current thread. GDB now asks for
1463 confirmation if the program had stopped for a signal and the user
1464 switched threads meanwhile.
1466 * "breakpoint always-inserted" modes "off" and "auto" merged.
1468 Now, when 'breakpoint always-inserted mode' is set to "off", GDB
1469 won't remove breakpoints from the target until all threads stop,
1470 even in non-stop mode. The "auto" mode has been removed, and "off"
1471 is now the default mode.
1475 set debug symbol-lookup
1476 show debug symbol-lookup
1477 Control display of debugging info regarding symbol lookup.
1481 ** The -list-thread-groups command outputs an exit-code field for
1482 inferiors that have exited.
1486 MIPS SDE mips*-sde*-elf*
1490 Support for these obsolete configurations has been removed.
1492 Alpha running OSF/1 (or Tru64) alpha*-*-osf*
1493 SGI Irix-5.x mips-*-irix5*
1494 SGI Irix-6.x mips-*-irix6*
1495 VAX running (4.2 - 4.3 Reno) BSD vax-*-bsd*
1496 VAX running Ultrix vax-*-ultrix*
1498 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1499 and "assf"), have been removed. Use the "sharedlibrary" command, or
1500 its alias "share", instead.
1502 *** Changes in GDB 7.8
1504 * New command line options
1507 This is an alias for the --data-directory option.
1509 * GDB supports printing and modifying of variable length automatic arrays
1510 as specified in ISO C99.
1512 * The ARM simulator now supports instruction level tracing
1513 with or without disassembly.
1517 GDB now has support for scripting using Guile. Whether this is
1518 available is determined at configure time.
1519 Guile version 2.0 or greater is required.
1520 Guile version 2.0.9 is well tested, earlier 2.0 versions are not.
1522 * New commands (for set/show, see "New options" below)
1526 Invoke CODE by passing it to the Guile interpreter.
1530 Start a Guile interactive prompt (or "repl" for "read-eval-print loop").
1532 info auto-load guile-scripts [regexp]
1533 Print the list of automatically loaded Guile scripts.
1535 * The source command is now capable of sourcing Guile scripts.
1536 This feature is dependent on the debugger being built with Guile support.
1540 set print symbol-loading (off|brief|full)
1541 show print symbol-loading
1542 Control whether to print informational messages when loading symbol
1543 information for a file. The default is "full", but when debugging
1544 programs with large numbers of shared libraries the amount of output
1545 becomes less useful.
1547 set guile print-stack (none|message|full)
1548 show guile print-stack
1549 Show a stack trace when an error is encountered in a Guile script.
1551 set auto-load guile-scripts (on|off)
1552 show auto-load guile-scripts
1553 Control auto-loading of Guile script files.
1555 maint ada set ignore-descriptive-types (on|off)
1556 maint ada show ignore-descriptive-types
1557 Control whether the debugger should ignore descriptive types in Ada
1558 programs. The default is not to ignore the descriptive types. See
1559 the user manual for more details on descriptive types and the intended
1560 usage of this option.
1562 set auto-connect-native-target
1564 Control whether GDB is allowed to automatically connect to the
1565 native target for the run, attach, etc. commands when not connected
1566 to any target yet. See also "target native" below.
1568 set record btrace replay-memory-access (read-only|read-write)
1569 show record btrace replay-memory-access
1570 Control what memory accesses are allowed during replay.
1572 maint set target-async (on|off)
1573 maint show target-async
1574 This controls whether GDB targets operate in synchronous or
1575 asynchronous mode. Normally the default is asynchronous, if it is
1576 available; but this can be changed to more easily debug problems
1577 occurring only in synchronous mode.
1579 set mi-async (on|off)
1581 Control whether MI asynchronous mode is preferred. This supersedes
1582 "set target-async" of previous GDB versions.
1584 * "set target-async" is deprecated as a CLI option and is now an alias
1585 for "set mi-async" (only puts MI into async mode).
1587 * Background execution commands (e.g., "c&", "s&", etc.) are now
1588 possible ``out of the box'' if the target supports them. Previously
1589 the user would need to explicitly enable the possibility with the
1590 "set target-async on" command.
1592 * New features in the GDB remote stub, GDBserver
1594 ** New option --debug-format=option1[,option2,...] allows one to add
1595 additional text to each output. At present only timestamps
1596 are supported: --debug-format=timestamps.
1597 Timestamps can also be turned on with the
1598 "monitor set debug-format timestamps" command from GDB.
1600 * The 'record instruction-history' command now starts counting instructions
1601 at one. This also affects the instruction ranges reported by the
1602 'record function-call-history' command when given the /i modifier.
1604 * The command 'record function-call-history' supports a new modifier '/c' to
1605 indent the function names based on their call stack depth.
1606 The fields for the '/i' and '/l' modifier have been reordered.
1607 The source line range is now prefixed with 'at'.
1608 The instruction range is now prefixed with 'inst'.
1609 Both ranges are now printed as '<from>, <to>' to allow copy&paste to the
1610 "record instruction-history" and "list" commands.
1612 * The ranges given as arguments to the 'record function-call-history' and
1613 'record instruction-history' commands are now inclusive.
1615 * The btrace record target now supports the 'record goto' command.
1616 For locations inside the execution trace, the back trace is computed
1617 based on the information stored in the execution trace.
1619 * The btrace record target supports limited reverse execution and replay.
1620 The target does not record data and therefore does not allow reading
1621 memory or registers.
1623 * The "catch syscall" command now works on s390*-linux* targets.
1625 * The "compare-sections" command is no longer specific to target
1626 remote. It now works with all targets.
1628 * All native targets are now consistently called "native".
1629 Consequently, the "target child", "target GNU", "target djgpp",
1630 "target procfs" (Solaris/Irix/OSF/AIX) and "target darwin-child"
1631 commands have been replaced with "target native". The QNX/NTO port
1632 leaves the "procfs" target in place and adds a "native" target for
1633 consistency with other ports. The impact on users should be minimal
1634 as these commands previously either throwed an error, or were
1635 no-ops. The target's name is visible in the output of the following
1636 commands: "help target", "info target", "info files", "maint print
1639 * The "target native" command now connects to the native target. This
1640 can be used to launch native programs even when "set
1641 auto-connect-native-target" is set to off.
1643 * GDB now supports access to Intel MPX registers on GNU/Linux.
1645 * Support for Intel AVX-512 registers on GNU/Linux.
1646 Support displaying and modifying Intel AVX-512 registers
1647 $zmm0 - $zmm31 and $k0 - $k7 on GNU/Linux.
1649 * New remote packets
1651 qXfer:btrace:read's annex
1652 The qXfer:btrace:read packet supports a new annex 'delta' to read
1653 branch trace incrementally.
1657 ** Valid Python operations on gdb.Value objects representing
1658 structs/classes invoke the corresponding overloaded operators if
1660 ** New `Xmethods' feature in the Python API. Xmethods are
1661 additional methods or replacements for existing methods of a C++
1662 class. This feature is useful for those cases where a method
1663 defined in C++ source code could be inlined or optimized out by
1664 the compiler, making it unavailable to GDB.
1667 PowerPC64 GNU/Linux little-endian powerpc64le-*-linux*
1669 * The "dll-symbols" command, and its two aliases ("add-shared-symbol-files"
1670 and "assf"), have been deprecated. Use the "sharedlibrary" command, or
1671 its alias "share", instead.
1673 * The commands "set remotebaud" and "show remotebaud" are no longer
1674 supported. Use "set serial baud" and "show serial baud" (respectively)
1679 ** A new option "-gdb-set mi-async" replaces "-gdb-set
1680 target-async". The latter is left as a deprecated alias of the
1681 former for backward compatibility. If the target supports it,
1682 CLI background execution commands are now always possible by
1683 default, independently of whether the frontend stated a
1684 preference for asynchronous execution with "-gdb-set mi-async".
1685 Previously "-gdb-set target-async off" affected both MI execution
1686 commands and CLI execution commands.
1688 *** Changes in GDB 7.7
1690 * Improved support for process record-replay and reverse debugging on
1691 arm*-linux* targets. Support for thumb32 and syscall instruction
1692 recording has been added.
1694 * GDB now supports SystemTap SDT probes on AArch64 GNU/Linux.
1696 * GDB now supports Fission DWP file format version 2.
1697 http://gcc.gnu.org/wiki/DebugFission
1699 * New convenience function "$_isvoid", to check whether an expression
1700 is void. A void expression is an expression where the type of the
1701 result is "void". For example, some convenience variables may be
1702 "void" when evaluated (e.g., "$_exitcode" before the execution of
1703 the program being debugged; or an undefined convenience variable).
1704 Another example, when calling a function whose return type is
1707 * The "maintenance print objfiles" command now takes an optional regexp.
1709 * The "catch syscall" command now works on arm*-linux* targets.
1711 * GDB now consistently shows "<not saved>" when printing values of
1712 registers the debug info indicates have not been saved in the frame
1713 and there's nowhere to retrieve them from
1714 (callee-saved/call-clobbered registers):
1719 (gdb) info registers rax
1722 Before, the former would print "<optimized out>", and the latter
1723 "*value not available*".
1725 * New script contrib/gdb-add-index.sh for adding .gdb_index sections
1730 ** Frame filters and frame decorators have been added.
1731 ** Temporary breakpoints are now supported.
1732 ** Line tables representation has been added.
1733 ** New attribute 'parent_type' for gdb.Field objects.
1734 ** gdb.Field objects can be used as subscripts on gdb.Value objects.
1735 ** New attribute 'name' for gdb.Type objects.
1739 Nios II ELF nios2*-*-elf
1740 Nios II GNU/Linux nios2*-*-linux
1741 Texas Instruments MSP430 msp430*-*-elf
1743 * Removed native configurations
1745 Support for these a.out NetBSD and OpenBSD obsolete configurations has
1746 been removed. ELF variants of these configurations are kept supported.
1748 arm*-*-netbsd* but arm*-*-netbsdelf* is kept supported.
1749 i[34567]86-*-netbsd* but i[34567]86-*-netbsdelf* is kept supported.
1750 i[34567]86-*-openbsd[0-2].* but i[34567]86-*-openbsd* is kept supported.
1751 i[34567]86-*-openbsd3.[0-3]
1752 m68*-*-netbsd* but m68*-*-netbsdelf* is kept supported.
1753 sparc-*-netbsd* but sparc-*-netbsdelf* is kept supported.
1754 vax-*-netbsd* but vax-*-netbsdelf* is kept supported.
1758 Like "catch throw", but catches a re-thrown exception.
1759 maint check-psymtabs
1760 Renamed from old "maint check-symtabs".
1762 Perform consistency checks on symtabs.
1763 maint expand-symtabs
1764 Expand symtabs matching an optional regexp.
1767 Display the details of GDB configure-time options.
1769 maint set|show per-command
1770 maint set|show per-command space
1771 maint set|show per-command time
1772 maint set|show per-command symtab
1773 Enable display of per-command gdb resource usage.
1775 remove-symbol-file FILENAME
1776 remove-symbol-file -a ADDRESS
1777 Remove a symbol file added via add-symbol-file. The file to remove
1778 can be identified by its filename or by an address that lies within
1779 the boundaries of this symbol file in memory.
1782 info exceptions REGEXP
1783 Display the list of Ada exceptions defined in the program being
1784 debugged. If provided, only the exceptions whose names match REGEXP
1789 set debug symfile off|on
1791 Control display of debugging info regarding reading symbol files and
1792 symbol tables within those files
1794 set print raw frame-arguments
1795 show print raw frame-arguments
1796 Set/show whether to print frame arguments in raw mode,
1797 disregarding any defined pretty-printers.
1799 set remote trace-status-packet
1800 show remote trace-status-packet
1801 Set/show the use of remote protocol qTStatus packet.
1805 Control display of debugging messages related to Nios II targets.
1809 Control whether target-assisted range stepping is enabled.
1811 set startup-with-shell
1812 show startup-with-shell
1813 Specifies whether Unix child processes are started via a shell or
1818 Use the target memory cache for accesses to the code segment. This
1819 improves performance of remote debugging (particularly disassembly).
1821 * You can now use a literal value 'unlimited' for options that
1822 interpret 0 or -1 as meaning "unlimited". E.g., "set
1823 trace-buffer-size unlimited" is now an alias for "set
1824 trace-buffer-size -1" and "set height unlimited" is now an alias for
1827 * The "set debug symtab-create" debugging option of GDB has been changed to
1828 accept a verbosity level. 0 means "off", 1 provides basic debugging
1829 output, and values of 2 or greater provides more verbose output.
1831 * New command-line options
1833 Display the details of GDB configure-time options.
1835 * The command 'tsave' can now support new option '-ctf' to save trace
1836 buffer in Common Trace Format.
1838 * Newly installed $prefix/bin/gcore acts as a shell interface for the
1841 * GDB now implements the the C++ 'typeid' operator.
1843 * The new convenience variable $_exception holds the exception being
1844 thrown or caught at an exception-related catchpoint.
1846 * The exception-related catchpoints, like "catch throw", now accept a
1847 regular expression which can be used to filter exceptions by type.
1849 * The new convenience variable $_exitsignal is automatically set to
1850 the terminating signal number when the program being debugged dies
1851 due to an uncaught signal.
1855 ** All MI commands now accept an optional "--language" option.
1856 Support for this feature can be verified by using the "-list-features"
1857 command, which should contain "language-option".
1859 ** The new command -info-gdb-mi-command allows the user to determine
1860 whether a GDB/MI command is supported or not.
1862 ** The "^error" result record returned when trying to execute an undefined
1863 GDB/MI command now provides a variable named "code" whose content is the
1864 "undefined-command" error code. Support for this feature can be verified
1865 by using the "-list-features" command, which should contain
1866 "undefined-command-error-code".
1868 ** The -trace-save MI command can optionally save trace buffer in Common
1871 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
1873 ** The command -data-list-register-values now accepts an optional
1874 "--skip-unavailable" option. When used, only the available registers
1877 ** The new command -trace-frame-collected dumps collected variables,
1878 computed expressions, tvars, memory and registers in a traceframe.
1880 ** The commands -stack-list-locals, -stack-list-arguments and
1881 -stack-list-variables now accept an option "--skip-unavailable".
1882 When used, only the available locals or arguments are displayed.
1884 ** The -exec-run command now accepts an optional "--start" option.
1885 When used, the command follows the same semantics as the "start"
1886 command, stopping the program's execution at the start of its
1887 main subprogram. Support for this feature can be verified using
1888 the "-list-features" command, which should contain
1889 "exec-run-start-option".
1891 ** The new commands -catch-assert and -catch-exceptions insert
1892 catchpoints stopping the program when Ada exceptions are raised.
1894 ** The new command -info-ada-exceptions provides the equivalent of
1895 the new "info exceptions" command.
1897 * New system-wide configuration scripts
1898 A GDB installation now provides scripts suitable for use as system-wide
1899 configuration scripts for the following systems:
1903 * GDB now supports target-assigned range stepping with remote targets.
1904 This improves the performance of stepping source lines by reducing
1905 the number of control packets from/to GDB. See "New remote packets"
1908 * GDB now understands the element 'tvar' in the XML traceframe info.
1909 It has the id of the collected trace state variables.
1911 * On S/390 targets that provide the transactional-execution feature,
1912 the program interruption transaction diagnostic block (TDB) is now
1913 represented as a number of additional "registers" in GDB.
1915 * New remote packets
1919 The vCont packet supports a new 'r' action, that tells the remote
1920 stub to step through an address range itself, without GDB
1921 involvemement at each single-step.
1923 qXfer:libraries-svr4:read's annex
1924 The previously unused annex of the qXfer:libraries-svr4:read packet
1925 is now used to support passing an argument list. The remote stub
1926 reports support for this argument list to GDB's qSupported query.
1927 The defined arguments are "start" and "prev", used to reduce work
1928 necessary for library list updating, resulting in significant
1931 * New features in the GDB remote stub, GDBserver
1933 ** GDBserver now supports target-assisted range stepping. Currently
1934 enabled on x86/x86_64 GNU/Linux targets.
1936 ** GDBserver now adds element 'tvar' in the XML in the reply to
1937 'qXfer:traceframe-info:read'. It has the id of the collected
1938 trace state variables.
1940 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
1943 * New 'z' formatter for printing and examining memory, this displays the
1944 value as hexadecimal zero padded on the left to the size of the type.
1946 * GDB can now use Windows x64 unwinding data.
1948 * The "set remotebaud" command has been replaced by "set serial baud".
1949 Similarly, "show remotebaud" has been replaced by "show serial baud".
1950 The "set remotebaud" and "show remotebaud" commands are still available
1951 to provide backward compatibility with older versions of GDB.
1953 *** Changes in GDB 7.6
1955 * Target record has been renamed to record-full.
1956 Record/replay is now enabled with the "record full" command.
1957 This also affects settings that are associated with full record/replay
1958 that have been moved from "set/show record" to "set/show record full":
1960 set|show record full insn-number-max
1961 set|show record full stop-at-limit
1962 set|show record full memory-query
1964 * A new record target "record-btrace" has been added. The new target
1965 uses hardware support to record the control-flow of a process. It
1966 does not support replaying the execution, but it implements the
1967 below new commands for investigating the recorded execution log.
1968 This new recording method can be enabled using:
1972 The "record-btrace" target is only available on Intel Atom processors
1973 and requires a Linux kernel 2.6.32 or later.
1975 * Two new commands have been added for record/replay to give information
1976 about the recorded execution without having to replay the execution.
1977 The commands are only supported by "record btrace".
1979 record instruction-history prints the execution history at
1980 instruction granularity
1982 record function-call-history prints the execution history at
1983 function granularity
1985 * New native configurations
1987 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
1988 FreeBSD/powerpc powerpc*-*-freebsd
1989 x86_64/Cygwin x86_64-*-cygwin*
1990 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
1994 ARM AArch64 aarch64*-*-elf
1995 ARM AArch64 GNU/Linux aarch64*-*-linux
1996 Lynx 178 PowerPC powerpc-*-lynx*178
1997 x86_64/Cygwin x86_64-*-cygwin*
1998 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
2000 * If the configured location of system.gdbinit file (as given by the
2001 --with-system-gdbinit option at configure time) is in the
2002 data-directory (as specified by --with-gdb-datadir at configure
2003 time) or in one of its subdirectories, then GDB will look for the
2004 system-wide init file in the directory specified by the
2005 --data-directory command-line option.
2007 * New command line options:
2009 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
2010 other initialization files, unlike -nx which disables all of them.
2012 * Removed command line options
2014 -epoch This was used by the gdb mode in Epoch, an ancient fork of
2017 * The 'ptype' and 'whatis' commands now accept an argument to control
2020 * 'info proc' now works on some core files.
2024 ** Vectors can be created with gdb.Type.vector.
2026 ** Python's atexit.register now works in GDB.
2028 ** Types can be pretty-printed via a Python API.
2030 ** Python 3 is now supported (in addition to Python 2.4 or later)
2032 ** New class gdb.Architecture exposes GDB's internal representation
2033 of architecture in the Python API.
2035 ** New method Frame.architecture returns the gdb.Architecture object
2036 corresponding to the frame's architecture.
2038 * New Python-based convenience functions:
2040 ** $_memeq(buf1, buf2, length)
2041 ** $_streq(str1, str2)
2043 ** $_regex(str, regex)
2045 * The 'cd' command now defaults to using '~' (the home directory) if not
2048 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
2049 default for GCC since November 2000.
2051 * The command 'forward-search' can now be abbreviated as 'fo'.
2053 * The command 'info tracepoints' can now display 'installed on target'
2054 or 'not installed on target' for each non-pending location of tracepoint.
2056 * New configure options
2058 --enable-libmcheck/--disable-libmcheck
2059 By default, development versions are built with -lmcheck on hosts
2060 that support it, in order to help track memory corruption issues.
2061 Release versions, on the other hand, are built without -lmcheck
2062 by default. The --enable-libmcheck/--disable-libmcheck configure
2063 options allow the user to override that default.
2064 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
2065 This configure option allows the user to build GDB with
2066 libbabeltrace using which GDB can read Common Trace Format data.
2068 * New commands (for set/show, see "New options" below)
2071 Catch signals. This is similar to "handle", but allows commands and
2072 conditions to be attached.
2075 List the BFDs known to GDB.
2077 python-interactive [command]
2079 Start a Python interactive prompt, or evaluate the optional command
2080 and print the result of expressions.
2083 "py" is a new alias for "python".
2085 enable type-printer [name]...
2086 disable type-printer [name]...
2087 Enable or disable type printers.
2091 ** For the Renesas Super-H architecture, the "regs" command has been removed
2092 (has been deprecated in GDB 7.5), and "info all-registers" should be used
2097 set print type methods (on|off)
2098 show print type methods
2099 Control whether method declarations are displayed by "ptype".
2100 The default is to show them.
2102 set print type typedefs (on|off)
2103 show print type typedefs
2104 Control whether typedef definitions are displayed by "ptype".
2105 The default is to show them.
2107 set filename-display basename|relative|absolute
2108 show filename-display
2109 Control the way in which filenames is displayed.
2110 The default is "relative", which preserves previous behavior.
2112 set trace-buffer-size
2113 show trace-buffer-size
2114 Request target to change the size of trace buffer.
2116 set remote trace-buffer-size-packet auto|on|off
2117 show remote trace-buffer-size-packet
2118 Control the use of the remote protocol `QTBuffer:size' packet.
2122 Control display of debugging messages related to ARM AArch64.
2125 set debug coff-pe-read
2126 show debug coff-pe-read
2127 Control display of debugging messages related to reading of COFF/PE
2132 Control display of debugging messages related to Mach-O symbols
2135 set debug notification
2136 show debug notification
2137 Control display of debugging info for async remote notification.
2141 ** Command parameter changes are now notified using new async record
2142 "=cmd-param-changed".
2143 ** Trace frame changes caused by command "tfind" are now notified using
2144 new async record "=traceframe-changed".
2145 ** The creation, deletion and modification of trace state variables
2146 are now notified using new async records "=tsv-created",
2147 "=tsv-deleted" and "=tsv-modified".
2148 ** The start and stop of process record are now notified using new
2149 async record "=record-started" and "=record-stopped".
2150 ** Memory changes are now notified using new async record
2152 ** The data-disassemble command response will include a "fullname" field
2153 containing the absolute file name when source has been requested.
2154 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
2155 command, to allow pattern filling of memory areas.
2156 ** New commands "-catch-load"/"-catch-unload" added for intercepting
2157 library load/unload events.
2158 ** The response to breakpoint commands and breakpoint async records
2159 includes an "installed" field containing a boolean state about each
2160 non-pending tracepoint location is whether installed on target or not.
2161 ** Output of the "-trace-status" command includes a "trace-file" field
2162 containing the name of the trace file being examined. This field is
2163 optional, and only present when examining a trace file.
2164 ** The "fullname" field is now always present along with the "file" field,
2165 even if the file cannot be found by GDB.
2167 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
2168 You must have the LZMA library available when configuring GDB for this
2169 feature to be enabled. For more information, see:
2170 http://fedoraproject.org/wiki/Features/MiniDebugInfo
2172 * New remote packets
2175 Set the size of trace buffer. The remote stub reports support for this
2176 packet to gdb's qSupported query.
2179 Enable Branch Trace Store (BTS)-based branch tracing for the current
2180 thread. The remote stub reports support for this packet to gdb's
2184 Disable branch tracing for the current thread. The remote stub reports
2185 support for this packet to gdb's qSupported query.
2188 Read the traced branches for the current thread. The remote stub
2189 reports support for this packet to gdb's qSupported query.
2191 *** Changes in GDB 7.5
2193 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
2194 for more x32 ABI info.
2196 * GDB now supports access to MIPS DSP registers on Linux targets.
2198 * GDB now supports debugging microMIPS binaries.
2200 * The "info os" command on GNU/Linux can now display information on
2201 several new classes of objects managed by the operating system:
2202 "info os procgroups" lists process groups
2203 "info os files" lists file descriptors
2204 "info os sockets" lists internet-domain sockets
2205 "info os shm" lists shared-memory regions
2206 "info os semaphores" lists semaphores
2207 "info os msg" lists message queues
2208 "info os modules" lists loaded kernel modules
2210 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
2211 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
2212 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
2213 options and inspect the probe arguments using the new $_probe_arg family
2214 of convenience variables. You can obtain more information about SystemTap
2215 in <http://sourceware.org/systemtap/>.
2217 * GDB now supports reversible debugging on ARM, it allows you to
2218 debug basic ARM and THUMB instructions, and provides
2219 record/replay support.
2221 * The option "symbol-reloading" has been deleted as it is no longer used.
2225 ** GDB commands implemented in Python can now be put in command class
2228 ** The "maint set python print-stack on|off" is now deleted.
2230 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
2231 apply "flag enum"-style pretty-printing to any enum.
2233 ** gdb.lookup_symbol can now work when there is no current frame.
2235 ** gdb.Symbol now has a 'line' attribute, holding the line number in
2236 the source at which the symbol was defined.
2238 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
2239 method 'value'. The former indicates whether the symbol needs a
2240 frame in order to compute its value, and the latter computes the
2243 ** A new method 'referenced_value' on gdb.Value objects which can
2244 dereference pointer as well as C++ reference values.
2246 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
2247 which return the global and static blocks (as gdb.Block objects),
2248 of the underlying symbol table, respectively.
2250 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
2251 object associated with a PC value.
2253 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
2254 of the address range occupied by code for the current source line.
2256 * Go language support.
2257 GDB now supports debugging programs written in the Go programming
2260 * GDBserver now supports stdio connections.
2261 E.g. (gdb) target remote | ssh myhost gdbserver - hello
2263 * The binary "gdbtui" can no longer be built or installed.
2264 Use "gdb -tui" instead.
2266 * GDB will now print "flag" enums specially. A flag enum is one where
2267 all the enumerator values have no bits in common when pairwise
2268 "and"ed. When printing a value whose type is a flag enum, GDB will
2269 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
2270 (gdb) print (enum E) 3
2273 * The filename part of a linespec will now match trailing components
2274 of a source file name. For example, "break gcc/expr.c:1000" will
2275 now set a breakpoint in build/gcc/expr.c, but not
2276 build/libcpp/expr.c.
2278 * The "info proc" and "generate-core-file" commands will now also
2279 work on remote targets connected to GDBserver on Linux.
2281 * The command "info catch" has been removed. It has been disabled
2282 since December 2007.
2284 * The "catch exception" and "catch assert" commands now accept
2285 a condition at the end of the command, much like the "break"
2286 command does. For instance:
2288 (gdb) catch exception Constraint_Error if Barrier = True
2290 Previously, it was possible to add a condition to such catchpoints,
2291 but it had to be done as a second step, after the catchpoint had been
2292 created, using the "condition" command.
2294 * The "info static-tracepoint-marker" command will now also work on
2295 native Linux targets with in-process agent.
2297 * GDB can now set breakpoints on inlined functions.
2299 * The .gdb_index section has been updated to include symbols for
2300 inlined functions. GDB will ignore older .gdb_index sections by
2301 default, which could cause symbol files to be loaded more slowly
2302 until their .gdb_index sections can be recreated. The new command
2303 "set use-deprecated-index-sections on" will cause GDB to use any older
2304 .gdb_index sections it finds. This will restore performance, but the
2305 ability to set breakpoints on inlined functions will be lost in symbol
2306 files with older .gdb_index sections.
2308 The .gdb_index section has also been updated to record more information
2309 about each symbol. This speeds up the "info variables", "info functions"
2310 and "info types" commands when used with programs having the .gdb_index
2311 section, as well as speeding up debugging with shared libraries using
2312 the .gdb_index section.
2314 * Ada support for GDB/MI Variable Objects has been added.
2316 * GDB can now support 'breakpoint always-inserted mode' in 'record'
2321 ** New command -info-os is the MI equivalent of "info os".
2323 ** Output logs ("set logging" and related) now include MI output.
2327 ** "set use-deprecated-index-sections on|off"
2328 "show use-deprecated-index-sections on|off"
2329 Controls the use of deprecated .gdb_index sections.
2331 ** "catch load" and "catch unload" can be used to stop when a shared
2332 library is loaded or unloaded, respectively.
2334 ** "enable count" can be used to auto-disable a breakpoint after
2337 ** "info vtbl" can be used to show the virtual method tables for
2338 C++ and Java objects.
2340 ** "explore" and its sub commands "explore value" and "explore type"
2341 can be used to recursively explore values and types of
2342 expressions. These commands are available only if GDB is
2343 configured with '--with-python'.
2345 ** "info auto-load" shows status of all kinds of auto-loaded files,
2346 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
2347 sequences of commands files, "info auto-load python-scripts"
2348 shows status of auto-loading Python script files,
2349 "info auto-load local-gdbinit" shows status of loading init file
2350 (.gdbinit) from current directory and "info auto-load libthread-db" shows
2351 status of inferior specific thread debugging shared library loading.
2353 ** "info auto-load-scripts", "set auto-load-scripts on|off"
2354 and "show auto-load-scripts" commands have been deprecated, use their
2355 "info auto-load python-scripts", "set auto-load python-scripts on|off"
2356 and "show auto-load python-scripts" counterparts instead.
2358 ** "dprintf location,format,args..." creates a dynamic printf, which
2359 is basically a breakpoint that does a printf and immediately
2360 resumes your program's execution, so it is like a printf that you
2361 can insert dynamically at runtime instead of at compiletime.
2363 ** "set print symbol"
2365 Controls whether GDB attempts to display the symbol, if any,
2366 corresponding to addresses it prints. This defaults to "on", but
2367 you can set it to "off" to restore GDB's previous behavior.
2369 * Deprecated commands
2371 ** For the Renesas Super-H architecture, the "regs" command has been
2372 deprecated, and "info all-registers" should be used instead.
2376 Renesas RL78 rl78-*-elf
2377 HP OpenVMS ia64 ia64-hp-openvms*
2379 * GDBserver supports evaluation of breakpoint conditions. When
2380 support is advertised by GDBserver, GDB may be told to send the
2381 breakpoint conditions in bytecode form to GDBserver. GDBserver
2382 will only report the breakpoint trigger to GDB when its condition
2387 set mips compression
2388 show mips compression
2389 Select the compressed ISA encoding used in functions that have no symbol
2390 information available. The encoding can be set to either of:
2393 and is updated automatically from ELF file flags if available.
2395 set breakpoint condition-evaluation
2396 show breakpoint condition-evaluation
2397 Control whether breakpoint conditions are evaluated by GDB ("host") or by
2398 GDBserver ("target"). Default option "auto" chooses the most efficient
2400 This option can improve debugger efficiency depending on the speed of the
2404 Disable auto-loading globally.
2407 Show auto-loading setting of all kinds of auto-loaded files.
2409 set auto-load gdb-scripts on|off
2410 show auto-load gdb-scripts
2411 Control auto-loading of GDB canned sequences of commands files.
2413 set auto-load python-scripts on|off
2414 show auto-load python-scripts
2415 Control auto-loading of Python script files.
2417 set auto-load local-gdbinit on|off
2418 show auto-load local-gdbinit
2419 Control loading of init file (.gdbinit) from current directory.
2421 set auto-load libthread-db on|off
2422 show auto-load libthread-db
2423 Control auto-loading of inferior specific thread debugging shared library.
2425 set auto-load scripts-directory <dir1>[:<dir2>...]
2426 show auto-load scripts-directory
2427 Set a list of directories from which to load auto-loaded scripts.
2428 Automatically loaded Python scripts and GDB scripts are located in one
2429 of the directories listed by this option.
2430 The delimiter (':' above) may differ according to the host platform.
2432 set auto-load safe-path <dir1>[:<dir2>...]
2433 show auto-load safe-path
2434 Set a list of directories from which it is safe to auto-load files.
2435 The delimiter (':' above) may differ according to the host platform.
2437 set debug auto-load on|off
2438 show debug auto-load
2439 Control display of debugging info for auto-loading the files above.
2441 set dprintf-style gdb|call|agent
2443 Control the way in which a dynamic printf is performed; "gdb"
2444 requests a GDB printf command, while "call" causes dprintf to call a
2445 function in the inferior. "agent" requests that the target agent
2446 (such as GDBserver) do the printing.
2448 set dprintf-function <expr>
2449 show dprintf-function
2450 set dprintf-channel <expr>
2451 show dprintf-channel
2452 Set the function and optional first argument to the call when using
2453 the "call" style of dynamic printf.
2455 set disconnected-dprintf on|off
2456 show disconnected-dprintf
2457 Control whether agent-style dynamic printfs continue to be in effect
2458 after GDB disconnects.
2460 * New configure options
2462 --with-auto-load-dir
2463 Configure default value for the 'set auto-load scripts-directory'
2464 setting above. It defaults to '$debugdir:$datadir/auto-load',
2465 $debugdir representing global debugging info directories (available
2466 via 'show debug-file-directory') and $datadir representing GDB's data
2467 directory (available via 'show data-directory').
2469 --with-auto-load-safe-path
2470 Configure default value for the 'set auto-load safe-path' setting
2471 above. It defaults to the --with-auto-load-dir setting.
2473 --without-auto-load-safe-path
2474 Set 'set auto-load safe-path' to '/', effectively disabling this
2477 * New remote packets
2479 z0/z1 conditional breakpoints extension
2481 The z0/z1 breakpoint insertion packets have been extended to carry
2482 a list of conditional expressions over to the remote stub depending on the
2483 condition evaluation mode. The use of this extension can be controlled
2484 via the "set remote conditional-breakpoints-packet" command.
2488 Specify the signals which the remote stub may pass to the debugged
2489 program without GDB involvement.
2491 * New command line options
2493 --init-command=FILE, -ix Like --command, -x but execute it
2494 before loading inferior.
2495 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
2496 execute it before loading inferior.
2498 *** Changes in GDB 7.4
2500 * GDB now handles ambiguous linespecs more consistently; the existing
2501 FILE:LINE support has been expanded to other types of linespecs. A
2502 breakpoint will now be set on all matching locations in all
2503 inferiors, and locations will be added or removed according to
2506 * GDB now allows you to skip uninteresting functions and files when
2507 stepping with the "skip function" and "skip file" commands.
2509 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
2510 and "show remote hardware-watchpoint-length-limit". These allows to
2511 set or show the maximum length limit (in bytes) of a remote
2512 target hardware watchpoint.
2514 This allows e.g. to use "unlimited" hardware watchpoints with the
2515 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
2516 watchpoints are slower than real hardware watchpoints but are
2517 significantly faster than gdb software watchpoints.
2521 ** The register_pretty_printer function in module gdb.printing now takes
2522 an optional `replace' argument. If True, the new printer replaces any
2525 ** The "maint set python print-stack on|off" command has been
2526 deprecated and will be deleted in GDB 7.5.
2527 A new command: "set python print-stack none|full|message" has
2528 replaced it. Additionally, the default for "print-stack" is
2529 now "message", which just prints the error message without
2532 ** A prompt substitution hook (prompt_hook) is now available to the
2535 ** A new Python module, gdb.prompt has been added to the GDB Python
2536 modules library. This module provides functionality for
2537 escape sequences in prompts (used by set/show
2538 extended-prompt). These escape sequences are replaced by their
2539 corresponding value.
2541 ** Python commands and convenience-functions located in
2542 'data-directory'/python/gdb/command and
2543 'data-directory'/python/gdb/function are now automatically loaded
2546 ** Blocks now provide four new attributes. global_block and
2547 static_block will return the global and static blocks
2548 respectively. is_static and is_global are boolean attributes
2549 that indicate if the block is one of those two types.
2551 ** Symbols now provide the "type" attribute, the type of the symbol.
2553 ** The "gdb.breakpoint" function has been deprecated in favor of
2556 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
2557 of a function. This class is based on the "finish" command
2558 available in the CLI.
2560 ** Type objects for struct and union types now allow access to
2561 the fields using standard Python dictionary (mapping) methods.
2562 For example, "some_type['myfield']" now works, as does
2563 "some_type.items()".
2565 ** A new event "gdb.new_objfile" has been added, triggered by loading a
2568 ** A new function, "deep_items" has been added to the gdb.types
2569 module in the GDB Python modules library. This function returns
2570 an iterator over the fields of a struct or union type. Unlike
2571 the standard Python "iteritems" method, it will recursively traverse
2572 any anonymous fields.
2576 ** "*stopped" events can report several new "reason"s, such as
2579 ** Breakpoint changes are now notified using new async records, like
2580 "=breakpoint-modified".
2582 ** New command -ada-task-info.
2584 * libthread-db-search-path now supports two special values: $sdir and $pdir.
2585 $sdir specifies the default system locations of shared libraries.
2586 $pdir specifies the directory where the libpthread used by the application
2589 GDB no longer looks in $sdir and $pdir after it has searched the directories
2590 mentioned in libthread-db-search-path. If you want to search those
2591 directories, they must be specified in libthread-db-search-path.
2592 The default value of libthread-db-search-path on GNU/Linux and Solaris
2593 systems is now "$sdir:$pdir".
2595 $pdir is not supported by gdbserver, it is currently ignored.
2596 $sdir is supported by gdbserver.
2598 * New configure option --with-iconv-bin.
2599 When using the internationalization support like the one in the GNU C
2600 library, GDB will invoke the "iconv" program to get a list of supported
2601 character sets. If this program lives in a non-standard location, one can
2602 use this option to specify where to find it.
2604 * When natively debugging programs on PowerPC BookE processors running
2605 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
2606 watchpoints, which specify a mask in addition to an address to watch.
2607 The mask specifies that some bits of an address (the bits which are
2608 reset in the mask) should be ignored when matching the address accessed
2609 by the inferior against the watchpoint address. See the "PowerPC Embedded"
2610 section in the user manual for more details.
2612 * The new option --once causes GDBserver to stop listening for connections once
2613 the first connection is made. The listening port used by GDBserver will
2614 become available after that.
2616 * New commands "info macros" and "alias" have been added.
2618 * New function parameters suffix @entry specifies value of function parameter
2619 at the time the function got called. Entry values are available only since
2625 "!" is now an alias of the "shell" command.
2626 Note that no space is needed between "!" and SHELL COMMAND.
2630 watch EXPRESSION mask MASK_VALUE
2631 The watch command now supports the mask argument which allows creation
2632 of masked watchpoints, if the current architecture supports this feature.
2634 info auto-load-scripts [REGEXP]
2635 This command was formerly named "maintenance print section-scripts".
2636 It is now generally useful and is no longer a maintenance-only command.
2638 info macro [-all] [--] MACRO
2639 The info macro command has new options `-all' and `--'. The first for
2640 printing all definitions of a macro. The second for explicitly specifying
2641 the end of arguments and the beginning of the macro name in case the macro
2642 name starts with a hyphen.
2644 collect[/s] EXPRESSIONS
2645 The tracepoint collect command now takes an optional modifier "/s"
2646 that directs it to dereference pointer-to-character types and
2647 collect the bytes of memory up to a zero byte. The behavior is
2648 similar to what you see when you use the regular print command on a
2649 string. An optional integer following the "/s" sets a bound on the
2650 number of bytes that will be collected.
2653 The trace start command now interprets any supplied arguments as a
2654 note to be recorded with the trace run, with an effect similar to
2655 setting the variable trace-notes.
2658 The trace stop command now interprets any arguments as a note to be
2659 mentioned along with the tstatus report that the trace was stopped
2660 with a command. The effect is similar to setting the variable
2663 * Tracepoints can now be enabled and disabled at any time after a trace
2664 experiment has been started using the standard "enable" and "disable"
2665 commands. It is now possible to start a trace experiment with no enabled
2666 tracepoints; GDB will display a warning, but will allow the experiment to
2667 begin, assuming that tracepoints will be enabled as needed while the trace
2670 * Fast tracepoints on 32-bit x86-architectures can now be placed at
2671 locations with 4-byte instructions, when they were previously
2672 limited to locations with instructions of 5 bytes or longer.
2676 set debug dwarf2-read
2677 show debug dwarf2-read
2678 Turns on or off display of debugging messages related to reading
2679 DWARF debug info. The default is off.
2681 set debug symtab-create
2682 show debug symtab-create
2683 Turns on or off display of debugging messages related to symbol table
2684 creation. The default is off.
2687 show extended-prompt
2688 Set the GDB prompt, and allow escape sequences to be inserted to
2689 display miscellaneous information (see 'help set extended-prompt'
2690 for the list of sequences). This prompt (and any information
2691 accessed through the escape sequences) is updated every time the
2692 prompt is displayed.
2694 set print entry-values (both|compact|default|if-needed|no|only|preferred)
2695 show print entry-values
2696 Set printing of frame argument values at function entry. In some cases
2697 GDB can determine the value of function argument which was passed by the
2698 function caller, even if the value was modified inside the called function.
2700 set debug entry-values
2701 show debug entry-values
2702 Control display of debugging info for determining frame argument values at
2703 function entry and virtual tail call frames.
2705 set basenames-may-differ
2706 show basenames-may-differ
2707 Set whether a source file may have multiple base names.
2708 (A "base name" is the name of a file with the directory part removed.
2709 Example: The base name of "/home/user/hello.c" is "hello.c".)
2710 If set, GDB will canonicalize file names (e.g., expand symlinks)
2711 before comparing them. Canonicalization is an expensive operation,
2712 but it allows the same file be known by more than one base name.
2713 If not set (the default), all source files are assumed to have just
2714 one base name, and gdb will do file name comparisons more efficiently.
2720 Set a user name and notes for the current and any future trace runs.
2721 This is useful for long-running and/or disconnected traces, to
2722 inform others (or yourself) as to who is running the trace, supply
2723 contact information, or otherwise explain what is going on.
2725 set trace-stop-notes
2726 show trace-stop-notes
2727 Set a note attached to the trace run, that is displayed when the
2728 trace has been stopped by a tstop command. This is useful for
2729 instance as an explanation, if you are stopping a trace run that was
2730 started by someone else.
2732 * New remote packets
2736 Dynamically enable a tracepoint in a started trace experiment.
2740 Dynamically disable a tracepoint in a started trace experiment.
2744 Set the user and notes of the trace run.
2748 Query the current status of a tracepoint.
2752 Query the minimum length of instruction at which a fast tracepoint may
2755 * Dcache size (number of lines) and line-size are now runtime-configurable
2756 via "set dcache line" and "set dcache line-size" commands.
2760 Texas Instruments TMS320C6x tic6x-*-*
2764 Renesas RL78 rl78-*-elf
2766 *** Changes in GDB 7.3.1
2768 * The build failure for NetBSD and OpenBSD targets have now been fixed.
2770 *** Changes in GDB 7.3
2772 * GDB has a new command: "thread find [REGEXP]".
2773 It finds the thread id whose name, target id, or thread extra info
2774 matches the given regular expression.
2776 * The "catch syscall" command now works on mips*-linux* targets.
2778 * The -data-disassemble MI command now supports modes 2 and 3 for
2779 dumping the instruction opcodes.
2781 * New command line options
2783 -data-directory DIR Specify DIR as the "data-directory".
2784 This is mostly for testing purposes.
2786 * The "maint set python auto-load on|off" command has been renamed to
2787 "set auto-load-scripts on|off".
2789 * GDB has a new command: "set directories".
2790 It is like the "dir" command except that it replaces the
2791 source path list instead of augmenting it.
2793 * GDB now understands thread names.
2795 On GNU/Linux, "info threads" will display the thread name as set by
2796 prctl or pthread_setname_np.
2798 There is also a new command, "thread name", which can be used to
2799 assign a name internally for GDB to display.
2802 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
2803 has been integrated into GDB.
2807 ** The function gdb.Write now accepts an optional keyword 'stream'.
2808 This keyword, when provided, will direct the output to either
2809 stdout, stderr, or GDB's logging output.
2811 ** Parameters can now be be sub-classed in Python, and in particular
2812 you may implement the get_set_doc and get_show_doc functions.
2813 This improves how Parameter set/show documentation is processed
2814 and allows for more dynamic content.
2816 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
2817 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
2818 have an is_valid method.
2820 ** Breakpoints can now be sub-classed in Python, and in particular
2821 you may implement a 'stop' function that is executed each time
2822 the inferior reaches that breakpoint.
2824 ** New function gdb.lookup_global_symbol looks up a global symbol.
2826 ** GDB values in Python are now callable if the value represents a
2827 function. For example, if 'some_value' represents a function that
2828 takes two integer parameters and returns a value, you can call
2829 that function like so:
2831 result = some_value (10,20)
2833 ** Module gdb.types has been added.
2834 It contains a collection of utilities for working with gdb.Types objects:
2835 get_basic_type, has_field, make_enum_dict.
2837 ** Module gdb.printing has been added.
2838 It contains utilities for writing and registering pretty-printers.
2839 New classes: PrettyPrinter, SubPrettyPrinter,
2840 RegexpCollectionPrettyPrinter.
2841 New function: register_pretty_printer.
2843 ** New commands "info pretty-printers", "enable pretty-printer" and
2844 "disable pretty-printer" have been added.
2846 ** gdb.parameter("directories") is now available.
2848 ** New function gdb.newest_frame returns the newest frame in the
2851 ** The gdb.InferiorThread class has a new "name" attribute. This
2852 holds the thread's name.
2854 ** Python Support for Inferior events.
2855 Python scripts can add observers to be notified of events
2856 occurring in the process being debugged.
2857 The following events are currently supported:
2858 - gdb.events.cont Continue event.
2859 - gdb.events.exited Inferior exited event.
2860 - gdb.events.stop Signal received, and Breakpoint hit events.
2864 ** GDB now puts template parameters in scope when debugging in an
2865 instantiation. For example, if you have:
2867 template<int X> int func (void) { return X; }
2869 then if you step into func<5>, "print X" will show "5". This
2870 feature requires proper debuginfo support from the compiler; it
2871 was added to GCC 4.5.
2873 ** The motion commands "next", "finish", "until", and "advance" now
2874 work better when exceptions are thrown. In particular, GDB will
2875 no longer lose control of the inferior; instead, the GDB will
2876 stop the inferior at the point at which the exception is caught.
2877 This functionality requires a change in the exception handling
2878 code that was introduced in GCC 4.5.
2880 * GDB now follows GCC's rules on accessing volatile objects when
2881 reading or writing target state during expression evaluation.
2882 One notable difference to prior behavior is that "print x = 0"
2883 no longer generates a read of x; the value of the assignment is
2884 now always taken directly from the value being assigned.
2886 * GDB now has some support for using labels in the program's source in
2887 linespecs. For instance, you can use "advance label" to continue
2888 execution to a label.
2890 * GDB now has support for reading and writing a new .gdb_index
2891 section. This section holds a fast index of DWARF debugging
2892 information and can be used to greatly speed up GDB startup and
2893 operation. See the documentation for `save gdb-index' for details.
2895 * The "watch" command now accepts an optional "-location" argument.
2896 When used, this causes GDB to watch the memory referred to by the
2897 expression. Such a watchpoint is never deleted due to it going out
2900 * GDB now supports thread debugging of core dumps on GNU/Linux.
2902 GDB now activates thread debugging using the libthread_db library
2903 when debugging GNU/Linux core dumps, similarly to when debugging
2904 live processes. As a result, when debugging a core dump file, GDB
2905 is now able to display pthread_t ids of threads. For example, "info
2906 threads" shows the same output as when debugging the process when it
2907 was live. In earlier releases, you'd see something like this:
2910 * 1 LWP 6780 main () at main.c:10
2912 While now you see this:
2915 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
2917 It is also now possible to inspect TLS variables when debugging core
2920 When debugging a core dump generated on a machine other than the one
2921 used to run GDB, you may need to point GDB at the correct
2922 libthread_db library with the "set libthread-db-search-path"
2923 command. See the user manual for more details on this command.
2925 * When natively debugging programs on PowerPC BookE processors running
2926 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
2927 which stop execution of the inferior whenever it executes an instruction
2928 at any address within the specified range. See the "PowerPC Embedded"
2929 section in the user manual for more details.
2931 * New features in the GDB remote stub, GDBserver
2933 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
2934 and i686 LynxOS (version 5.x).
2936 ** GDBserver is now supported on Blackfin Linux.
2938 * New native configurations
2940 ia64 HP-UX ia64-*-hpux*
2944 Analog Devices, Inc. Blackfin Processor bfin-*
2946 * Ada task switching is now supported on sparc-elf targets when
2947 debugging a program using the Ravenscar Profile. For more information,
2948 see the "Tasking Support when using the Ravenscar Profile" section
2949 in the GDB user manual.
2951 * Guile support was removed.
2953 * New features in the GNU simulator
2955 ** The --map-info flag lists all known core mappings.
2957 ** CFI flashes may be simulated via the "cfi" device.
2959 *** Changes in GDB 7.2
2961 * Shared library support for remote targets by default
2963 When GDB is configured for a generic, non-OS specific target, like
2964 for example, --target=arm-eabi or one of the many *-*-elf targets,
2965 GDB now queries remote stubs for loaded shared libraries using the
2966 `qXfer:libraries:read' packet. Previously, shared library support
2967 was always disabled for such configurations.
2971 ** Argument Dependent Lookup (ADL)
2973 In C++ ADL lookup directs function search to the namespaces of its
2974 arguments even if the namespace has not been imported.
2984 Here the compiler will search for `foo' in the namespace of 'b'
2985 and find A::foo. GDB now supports this. This construct is commonly
2986 used in the Standard Template Library for operators.
2988 ** Improved User Defined Operator Support
2990 In addition to member operators, GDB now supports lookup of operators
2991 defined in a namespace and imported with a `using' directive, operators
2992 defined in the global scope, operators imported implicitly from an
2993 anonymous namespace, and the ADL operators mentioned in the previous
2995 GDB now also supports proper overload resolution for all the previously
2996 mentioned flavors of operators.
2998 ** static const class members
3000 Printing of static const class members that are initialized in the
3001 class definition has been fixed.
3003 * Windows Thread Information Block access.
3005 On Windows targets, GDB now supports displaying the Windows Thread
3006 Information Block (TIB) structure. This structure is visible either
3007 by using the new command `info w32 thread-information-block' or, by
3008 dereferencing the new convenience variable named `$_tlb', a
3009 thread-specific pointer to the TIB. This feature is also supported
3010 when remote debugging using GDBserver.
3012 * Static tracepoints
3014 Static tracepoints are calls in the user program into a tracing
3015 library. One such library is a port of the LTTng kernel tracer to
3016 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
3017 When debugging with GDBserver, GDB now supports combining the GDB
3018 tracepoint machinery with such libraries. For example: the user can
3019 use GDB to probe a static tracepoint marker (a call from the user
3020 program into the tracing library) with the new "strace" command (see
3021 "New commands" below). This creates a "static tracepoint" in the
3022 breakpoint list, that can be manipulated with the same feature set
3023 as fast and regular tracepoints. E.g., collect registers, local and
3024 global variables, collect trace state variables, and define
3025 tracepoint conditions. In addition, the user can collect extra
3026 static tracepoint marker specific data, by collecting the new
3027 $_sdata internal variable. When analyzing the trace buffer, you can
3028 inspect $_sdata like any other variable available to GDB. For more
3029 information, see the "Tracepoints" chapter in GDB user manual. New
3030 remote packets have been defined to support static tracepoints, see
3031 the "New remote packets" section below.
3033 * Better reconstruction of tracepoints after disconnected tracing
3035 GDB will attempt to download the original source form of tracepoint
3036 definitions when starting a trace run, and then will upload these
3037 upon reconnection to the target, resulting in a more accurate
3038 reconstruction of the tracepoints that are in use on the target.
3042 You can now exercise direct control over the ways that GDB can
3043 affect your program. For instance, you can disallow the setting of
3044 breakpoints, so that the program can run continuously (assuming
3045 non-stop mode). In addition, the "observer" variable is available
3046 to switch all of the different controls; in observer mode, GDB
3047 cannot affect the target's behavior at all, which is useful for
3048 tasks like diagnosing live systems in the field.
3050 * The new convenience variable $_thread holds the number of the
3053 * New remote packets
3057 Return the address of the Windows Thread Information Block of a given thread.
3061 In response to several of the tracepoint packets, the target may now
3062 also respond with a number of intermediate `qRelocInsn' request
3063 packets before the final result packet, to have GDB handle
3064 relocating an instruction to execute at a different address. This
3065 is particularly useful for stubs that support fast tracepoints. GDB
3066 reports support for this feature in the qSupported packet.
3070 List static tracepoint markers in the target program.
3074 List static tracepoint markers at a given address in the target
3077 qXfer:statictrace:read
3079 Read the static trace data collected (by a `collect $_sdata'
3080 tracepoint action). The remote stub reports support for this packet
3081 to gdb's qSupported query.
3085 Send the current settings of GDB's permission flags.
3089 Send part of the source (textual) form of a tracepoint definition,
3090 which includes location, conditional, and action list.
3092 * The source command now accepts a -s option to force searching for the
3093 script in the source search path even if the script name specifies
3096 * New features in the GDB remote stub, GDBserver
3098 - GDBserver now support tracepoints (including fast tracepoints, and
3099 static tracepoints). The feature is currently supported by the
3100 i386-linux and amd64-linux builds. See the "Tracepoints support
3101 in gdbserver" section in the manual for more information.
3103 GDBserver JIT compiles the tracepoint's conditional agent
3104 expression bytecode into native code whenever possible for low
3105 overhead dynamic tracepoints conditionals. For such tracepoints,
3106 an expression that examines program state is evaluated when the
3107 tracepoint is reached, in order to determine whether to capture
3108 trace data. If the condition is simple and false, processing the
3109 tracepoint finishes very quickly and no data is gathered.
3111 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
3112 for static tracepoints support.
3114 - GDBserver now supports x86_64 Windows 64-bit debugging.
3116 * GDB now sends xmlRegisters= in qSupported packet to indicate that
3117 it understands register description.
3119 * The --batch flag now disables pagination and queries.
3121 * X86 general purpose registers
3123 GDB now supports reading/writing byte, word and double-word x86
3124 general purpose registers directly. This means you can use, say,
3125 $ah or $ax to refer, respectively, to the byte register AH and
3126 16-bit word register AX that are actually portions of the 32-bit
3127 register EAX or 64-bit register RAX.
3129 * The `commands' command now accepts a range of breakpoints to modify.
3130 A plain `commands' following a command that creates multiple
3131 breakpoints affects all the breakpoints set by that command. This
3132 applies to breakpoints set by `rbreak', and also applies when a
3133 single `break' command creates multiple breakpoints (e.g.,
3134 breakpoints on overloaded c++ functions).
3136 * The `rbreak' command now accepts a filename specification as part of
3137 its argument, limiting the functions selected by the regex to those
3138 in the specified file.
3140 * Support for remote debugging Windows and SymbianOS shared libraries
3141 from Unix hosts has been improved. Non Windows GDB builds now can
3142 understand target reported file names that follow MS-DOS based file
3143 system semantics, such as file names that include drive letters and
3144 use the backslash character as directory separator. This makes it
3145 possible to transparently use the "set sysroot" and "set
3146 solib-search-path" on Unix hosts to point as host copies of the
3147 target's shared libraries. See the new command "set
3148 target-file-system-kind" described below, and the "Commands to
3149 specify files" section in the user manual for more information.
3153 eval template, expressions...
3154 Convert the values of one or more expressions under the control
3155 of the string template to a command line, and call it.
3157 set target-file-system-kind unix|dos-based|auto
3158 show target-file-system-kind
3159 Set or show the assumed file system kind for target reported file
3162 save breakpoints <filename>
3163 Save all current breakpoint definitions to a file suitable for use
3164 in a later debugging session. To read the saved breakpoint
3165 definitions, use the `source' command.
3167 `save tracepoints' is a new alias for `save-tracepoints'. The latter
3170 info static-tracepoint-markers
3171 Display information about static tracepoint markers in the target.
3173 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
3174 Define a static tracepoint by probing a marker at the given
3175 function, line, address, or marker ID.
3179 Enable and disable observer mode.
3181 set may-write-registers on|off
3182 set may-write-memory on|off
3183 set may-insert-breakpoints on|off
3184 set may-insert-tracepoints on|off
3185 set may-insert-fast-tracepoints on|off
3186 set may-interrupt on|off
3187 Set individual permissions for GDB effects on the target. Note that
3188 some of these settings can have undesirable or surprising
3189 consequences, particularly when changed in the middle of a session.
3190 For instance, disabling the writing of memory can prevent
3191 breakpoints from being inserted, cause single-stepping to fail, or
3192 even crash your program, if you disable after breakpoints have been
3193 inserted. However, GDB should not crash.
3195 set record memory-query on|off
3196 show record memory-query
3197 Control whether to stop the inferior if memory changes caused
3198 by an instruction cannot be recorded.
3203 The disassemble command now supports "start,+length" form of two arguments.
3207 ** GDB now provides a new directory location, called the python directory,
3208 where Python scripts written for GDB can be installed. The location
3209 of that directory is <data-directory>/python, where <data-directory>
3210 is the GDB data directory. For more details, see section `Scripting
3211 GDB using Python' in the manual.
3213 ** The GDB Python API now has access to breakpoints, symbols, symbol
3214 tables, program spaces, inferiors, threads and frame's code blocks.
3215 Additionally, GDB Parameters can now be created from the API, and
3216 manipulated via set/show in the CLI.
3218 ** New functions gdb.target_charset, gdb.target_wide_charset,
3219 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
3221 ** New exception gdb.GdbError.
3223 ** Pretty-printers are now also looked up in the current program space.
3225 ** Pretty-printers can now be individually enabled and disabled.
3227 ** GDB now looks for names of Python scripts to auto-load in a
3228 special section named `.debug_gdb_scripts', in addition to looking
3229 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
3231 * Tracepoint actions were unified with breakpoint commands. In particular,
3232 there are no longer differences in "info break" output for breakpoints and
3233 tracepoints and the "commands" command can be used for both tracepoints and
3234 regular breakpoints.
3238 ARM Symbian arm*-*-symbianelf*
3240 * D language support.
3241 GDB now supports debugging programs written in the D programming
3244 * GDB now supports the extended ptrace interface for PowerPC which is
3245 available since Linux kernel version 2.6.34. This automatically enables
3246 any hardware breakpoints and additional hardware watchpoints available in
3247 the processor. The old ptrace interface exposes just one hardware
3248 watchpoint and no hardware breakpoints.
3250 * GDB is now able to use the Data Value Compare (DVC) register available on
3251 embedded PowerPC processors to implement in hardware simple watchpoint
3252 conditions of the form:
3254 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
3256 This works in native GDB running on Linux kernels with the extended ptrace
3257 interface mentioned above.
3259 *** Changes in GDB 7.1
3263 ** Namespace Support
3265 GDB now supports importing of namespaces in C++. This enables the
3266 user to inspect variables from imported namespaces. Support for
3267 namepace aliasing has also been added. So, if a namespace is
3268 aliased in the current scope (e.g. namepace C=A; ) the user can
3269 print variables using the alias (e.g. (gdb) print C::x).
3273 All known bugs relating to the printing of virtual base class were
3274 fixed. It is now possible to call overloaded static methods using a
3279 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
3280 and reinterpret_cast<> are now handled by the C++ expression parser.
3284 Xilinx MicroBlaze microblaze-*-*
3289 Xilinx MicroBlaze microblaze
3292 * Multi-program debugging.
3294 GDB now has support for multi-program (a.k.a. multi-executable or
3295 multi-exec) debugging. This allows for debugging multiple inferiors
3296 simultaneously each running a different program under the same GDB
3297 session. See "Debugging Multiple Inferiors and Programs" in the
3298 manual for more information. This implied some user visible changes
3299 in the multi-inferior support. For example, "info inferiors" now
3300 lists inferiors that are not running yet or that have exited
3301 already. See also "New commands" and "New options" below.
3303 * New tracing features
3305 GDB's tracepoint facility now includes several new features:
3307 ** Trace state variables
3309 GDB tracepoints now include support for trace state variables, which
3310 are variables managed by the target agent during a tracing
3311 experiment. They are useful for tracepoints that trigger each
3312 other, so for instance one tracepoint can count hits in a variable,
3313 and then a second tracepoint has a condition that is true when the
3314 count reaches a particular value. Trace state variables share the
3315 $-syntax of GDB convenience variables, and can appear in both
3316 tracepoint actions and condition expressions. Use the "tvariable"
3317 command to create, and "info tvariables" to view; see "Trace State
3318 Variables" in the manual for more detail.
3322 GDB now includes an option for defining fast tracepoints, which
3323 targets may implement more efficiently, such as by installing a jump
3324 into the target agent rather than a trap instruction. The resulting
3325 speedup can be by two orders of magnitude or more, although the
3326 tradeoff is that some program locations on some target architectures
3327 might not allow fast tracepoint installation, for instance if the
3328 instruction to be replaced is shorter than the jump. To request a
3329 fast tracepoint, use the "ftrace" command, with syntax identical to
3330 the regular trace command.
3332 ** Disconnected tracing
3334 It is now possible to detach GDB from the target while it is running
3335 a trace experiment, then reconnect later to see how the experiment
3336 is going. In addition, a new variable disconnected-tracing lets you
3337 tell the target agent whether to continue running a trace if the
3338 connection is lost unexpectedly.
3342 GDB now has the ability to save the trace buffer into a file, and
3343 then use that file as a target, similarly to you can do with
3344 corefiles. You can select trace frames, print data that was
3345 collected in them, and use tstatus to display the state of the
3346 tracing run at the moment that it was saved. To create a trace
3347 file, use "tsave <filename>", and to use it, do "target tfile
3350 ** Circular trace buffer
3352 You can ask the target agent to handle the trace buffer as a
3353 circular buffer, discarding the oldest trace frames to make room for
3354 newer ones, by setting circular-trace-buffer to on. This feature may
3355 not be available for all target agents.
3360 The disassemble command, when invoked with two arguments, now requires
3361 the arguments to be comma-separated.
3364 The info variables command now displays variable definitions. Files
3365 which only declare a variable are not shown.
3368 The source command is now capable of sourcing Python scripts.
3369 This feature is dependent on the debugger being build with Python
3372 Related to this enhancement is also the introduction of a new command
3373 "set script-extension" (see below).
3375 * New commands (for set/show, see "New options" below)
3377 record save [<FILENAME>]
3378 Save a file (in core file format) containing the process record
3379 execution log for replay debugging at a later time.
3381 record restore <FILENAME>
3382 Restore the process record execution log that was saved at an
3383 earlier time, for replay debugging.
3385 add-inferior [-copies <N>] [-exec <FILENAME>]
3388 clone-inferior [-copies <N>] [ID]
3389 Make a new inferior ready to execute the same program another
3390 inferior has loaded.
3395 maint info program-spaces
3396 List the program spaces loaded into GDB.
3398 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
3399 show remote interrupt-sequence
3400 Allow the user to select one of ^C, a BREAK signal or BREAK-g
3401 as the sequence to the remote target in order to interrupt the execution.
3402 Ctrl-C is a default. Some system prefers BREAK which is high level of
3403 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
3404 Magic SysRq g. It is BREAK signal and character 'g'.
3406 set remote interrupt-on-connect [on | off]
3407 show remote interrupt-on-connect
3408 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
3409 remote target when gdb connects to it. This is needed when you debug
3412 set remotebreak [on | off]
3414 Deprecated. Use "set/show remote interrupt-sequence" instead.
3416 tvariable $NAME [ = EXP ]
3417 Create or modify a trace state variable.
3420 List trace state variables and their values.
3422 delete tvariable $NAME ...
3423 Delete one or more trace state variables.
3426 Evaluate the given expressions without collecting anything into the
3427 trace buffer. (Valid in tracepoint actions only.)
3429 ftrace FN / FILE:LINE / *ADDR
3430 Define a fast tracepoint at the given function, line, or address.
3432 * New expression syntax
3434 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
3435 GDB now parses 0b101010 identically with 42.
3439 set follow-exec-mode new|same
3440 show follow-exec-mode
3441 Control whether GDB reuses the same inferior across an exec call or
3442 creates a new one. This is useful to be able to restart the old
3443 executable after the inferior having done an exec call.
3445 set default-collect EXPR, ...
3446 show default-collect
3447 Define a list of expressions to be collected at each tracepoint.
3448 This is a useful way to ensure essential items are not overlooked,
3449 such as registers or a critical global variable.
3451 set disconnected-tracing
3452 show disconnected-tracing
3453 If set to 1, the target is instructed to continue tracing if it
3454 loses its connection to GDB. If 0, the target is to stop tracing
3457 set circular-trace-buffer
3458 show circular-trace-buffer
3459 If set to on, the target is instructed to use a circular trace buffer
3460 and discard the oldest trace frames instead of stopping the trace due
3461 to a full trace buffer. If set to off, the trace stops when the buffer
3462 fills up. Some targets may not support this.
3464 set script-extension off|soft|strict
3465 show script-extension
3466 If set to "off", the debugger does not perform any script language
3467 recognition, and all sourced files are assumed to be GDB scripts.
3468 If set to "soft" (the default), files are sourced according to
3469 filename extension, falling back to GDB scripts if the first
3471 If set to "strict", files are sourced according to filename extension.
3473 set ada trust-PAD-over-XVS on|off
3474 show ada trust-PAD-over-XVS
3475 If off, activate a workaround against a bug in the debugging information
3476 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
3477 the GCC sources for more information about the GNAT encoding and
3478 PAD types in particular). It is always safe to set this option to
3479 off, but this introduces a slight performance penalty. The default
3482 * Python API Improvements
3484 ** GDB provides the new class gdb.LazyString. This is useful in
3485 some pretty-printing cases. The new method gdb.Value.lazy_string
3486 provides a simple way to create objects of this type.
3488 ** The fields returned by gdb.Type.fields now have an
3489 `is_base_class' attribute.
3491 ** The new method gdb.Type.range returns the range of an array type.
3493 ** The new method gdb.parse_and_eval can be used to parse and
3494 evaluate an expression.
3496 * New remote packets
3499 Define a trace state variable.
3502 Get the current value of a trace state variable.
3505 Set desired tracing behavior upon disconnection.
3508 Set the trace buffer to be linear or circular.
3511 Get data about the tracepoints currently in use.
3515 Process record now works correctly with hardware watchpoints.
3517 Multiple bug fixes have been made to the mips-irix port, making it
3518 much more reliable. In particular:
3519 - Debugging threaded applications is now possible again. Previously,
3520 GDB would hang while starting the program, or while waiting for
3521 the program to stop at a breakpoint.
3522 - Attaching to a running process no longer hangs.
3523 - An error occurring while loading a core file has been fixed.
3524 - Changing the value of the PC register now works again. This fixes
3525 problems observed when using the "jump" command, or when calling
3526 a function from GDB, or even when assigning a new value to $pc.
3527 - With the "finish" and "return" commands, the return value for functions
3528 returning a small array is now correctly printed.
3529 - It is now possible to break on shared library code which gets executed
3530 during a shared library init phase (code executed while executing
3531 their .init section). Previously, the breakpoint would have no effect.
3532 - GDB is now able to backtrace through the signal handler for
3533 non-threaded programs.
3535 PIE (Position Independent Executable) programs debugging is now supported.
3536 This includes debugging execution of PIC (Position Independent Code) shared
3537 libraries although for that, it should be possible to run such libraries as an
3540 *** Changes in GDB 7.0
3542 * GDB now has an interface for JIT compilation. Applications that
3543 dynamically generate code can create symbol files in memory and register
3544 them with GDB. For users, the feature should work transparently, and
3545 for JIT developers, the interface is documented in the GDB manual in the
3546 "JIT Compilation Interface" chapter.
3548 * Tracepoints may now be conditional. The syntax is as for
3549 breakpoints; either an "if" clause appended to the "trace" command,
3550 or the "condition" command is available. GDB sends the condition to
3551 the target for evaluation using the same bytecode format as is used
3552 for tracepoint actions.
3554 * The disassemble command now supports: an optional /r modifier, print the
3555 raw instructions in hex as well as in symbolic form, and an optional /m
3556 modifier to print mixed source+assembly.
3558 * Process record and replay
3560 In a architecture environment that supports ``process record and
3561 replay'', ``process record and replay'' target can record a log of
3562 the process execution, and replay it with both forward and reverse
3565 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
3566 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
3567 set execution-direction {forward|reverse}, for targets that support
3570 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
3571 feature is available with a native GDB running on kernel version
3574 * GDB now has support for multi-byte and wide character sets on the
3575 target. Strings whose character type is wchar_t, char16_t, or
3576 char32_t are now correctly printed. GDB supports wide- and unicode-
3577 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
3578 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
3579 `printf'. This feature requires iconv to work properly; if your
3580 system does not have a working iconv, GDB can use GNU libiconv. See
3581 the installation instructions for more information.
3583 * GDB now supports automatic retrieval of shared library files from
3584 remote targets. To use this feature, specify a system root that begins
3585 with the `remote:' prefix, either via the `set sysroot' command or via
3586 the `--with-sysroot' configure-time option.
3588 * "info sharedlibrary" now takes an optional regex of libraries to show,
3589 and it now reports if a shared library has no debugging information.
3591 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
3592 now complete on file names.
3594 * When completing in expressions, gdb will attempt to limit
3595 completions to allowable structure or union fields, where appropriate.
3596 For instance, consider:
3598 # struct example { int f1; double f2; };
3599 # struct example variable;
3602 If the user types TAB at the end of this command line, the available
3603 completions will be "f1" and "f2".
3605 * Inlined functions are now supported. They show up in backtraces, and
3606 the "step", "next", and "finish" commands handle them automatically.
3608 * GDB now supports the token-splicing (##) and stringification (#)
3609 operators when expanding macros. It also supports variable-arity
3612 * GDB now supports inspecting extra signal information, exported by
3613 the new $_siginfo convenience variable. The feature is currently
3614 implemented on linux ARM, i386 and amd64.
3616 * GDB can now display the VFP floating point registers and NEON vector
3617 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
3618 can provide these registers (requires Linux 2.6.30 or later). Remote
3619 and simulator targets may also provide them.
3621 * New remote packets
3624 Search memory for a sequence of bytes.
3627 Turn off `+'/`-' protocol acknowledgments to permit more efficient
3628 operation over reliable transport links. Use of this packet is
3629 controlled by the `set remote noack-packet' command.
3632 Kill the process with the specified process ID. Use this in preference
3633 to `k' when multiprocess protocol extensions are supported.
3636 Obtains additional operating system information
3640 Read or write additional signal information.
3642 * Removed remote protocol undocumented extension
3644 An undocumented extension to the remote protocol's `S' stop reply
3645 packet that permited the stub to pass a process id was removed.
3646 Remote servers should use the `T' stop reply packet instead.
3648 * GDB now supports multiple function calling conventions according to the
3649 DWARF-2 DW_AT_calling_convention function attribute.
3651 * The SH target utilizes the aforementioned change to distinguish between gcc
3652 and Renesas calling convention. It also adds the new CLI commands
3653 `set/show sh calling-convention'.
3655 * GDB can now read compressed debug sections, as produced by GNU gold
3656 with the --compress-debug-sections=zlib flag.
3658 * 64-bit core files are now supported on AIX.
3660 * Thread switching is now supported on Tru64.
3662 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
3663 which will be allocated using malloc later in program execution.
3665 * The qXfer:libraries:read remote procotol packet now allows passing a
3666 list of section offsets.
3668 * On GNU/Linux, GDB can now attach to stopped processes. Several race
3669 conditions handling signals delivered during attach or thread creation
3670 have also been fixed.
3672 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
3673 From the user's standpoint, all unqualified instances of True and False
3674 are treated as the standard definitions, regardless of context.
3676 * GDB now parses C++ symbol and type names more flexibly. For
3679 template<typename T> class C { };
3682 GDB will now correctly handle all of:
3684 ptype C<char const *>
3685 ptype C<char const*>
3686 ptype C<const char *>
3687 ptype C<const char*>
3689 * New features in the GDB remote stub, gdbserver
3691 - The "--wrapper" command-line argument tells gdbserver to use a
3692 wrapper program to launch programs for debugging.
3694 - On PowerPC and S/390 targets, it is now possible to use a single
3695 gdbserver executable to debug both 32-bit and 64-bit programs.
3696 (This requires gdbserver itself to be built as a 64-bit executable.)
3698 - gdbserver uses the new noack protocol mode for TCP connections to
3699 reduce communications latency, if also supported and enabled in GDB.
3701 - Support for the sparc64-linux-gnu target is now included in
3704 - The amd64-linux build of gdbserver now supports debugging both
3705 32-bit and 64-bit programs.
3707 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
3708 now support hardware watchpoints, and will use them automatically
3713 GDB now has support for scripting using Python. Whether this is
3714 available is determined at configure time.
3716 New GDB commands can now be written in Python.
3718 * Ada tasking support
3720 Ada tasks can now be inspected in GDB. The following commands have
3724 Print the list of Ada tasks.
3726 Print detailed information about task number N.
3728 Print the task number of the current task.
3730 Switch the context of debugging to task number N.
3732 * Support for user-defined prefixed commands. The "define" command can
3733 add new commands to existing prefixes, e.g. "target".
3735 * Multi-inferior, multi-process debugging.
3737 GDB now has generalized support for multi-inferior debugging. See
3738 "Debugging Multiple Inferiors" in the manual for more information.
3739 Although availability still depends on target support, the command
3740 set is more uniform now. The GNU/Linux specific multi-forks support
3741 has been migrated to this new framework. This implied some user
3742 visible changes; see "New commands" and also "Removed commands"
3745 * Target descriptions can now describe the target OS ABI. See the
3746 "Target Description Format" section in the user manual for more
3749 * Target descriptions can now describe "compatible" architectures
3750 to indicate that the target can execute applications for a different
3751 architecture in addition to those for the main target architecture.
3752 See the "Target Description Format" section in the user manual for
3755 * Multi-architecture debugging.
3757 GDB now includes general supports for debugging applications on
3758 hybrid systems that use more than one single processor architecture
3759 at the same time. Each such hybrid architecture still requires
3760 specific support to be added. The only hybrid architecture supported
3761 in this version of GDB is the Cell Broadband Engine.
3763 * GDB now supports integrated debugging of Cell/B.E. applications that
3764 use both the PPU and SPU architectures. To enable support for hybrid
3765 Cell/B.E. debugging, you need to configure GDB to support both the
3766 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
3767 --enable-targets configure option.
3769 * Non-stop mode debugging.
3771 For some targets, GDB now supports an optional mode of operation in
3772 which you can examine stopped threads while other threads continue
3773 to execute freely. This is referred to as non-stop mode, with the
3774 old mode referred to as all-stop mode. See the "Non-Stop Mode"
3775 section in the user manual for more information.
3777 To be able to support remote non-stop debugging, a remote stub needs
3778 to implement the non-stop mode remote protocol extensions, as
3779 described in the "Remote Non-Stop" section of the user manual. The
3780 GDB remote stub, gdbserver, has been adjusted to support these
3781 extensions on linux targets.
3783 * New commands (for set/show, see "New options" below)
3785 catch syscall [NAME(S) | NUMBER(S)]
3786 Catch system calls. Arguments, which should be names of system
3787 calls or their numbers, mean catch only those syscalls. Without
3788 arguments, every syscall will be caught. When the inferior issues
3789 any of the specified syscalls, GDB will stop and announce the system
3790 call, both when it is called and when its call returns. This
3791 feature is currently available with a native GDB running on the
3792 Linux Kernel, under the following architectures: x86, x86_64,
3793 PowerPC and PowerPC64.
3795 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
3797 Search memory for a sequence of bytes.
3799 maint set python print-stack
3800 maint show python print-stack
3801 Show a stack trace when an error is encountered in a Python script.
3804 Invoke CODE by passing it to the Python interpreter.
3809 These allow macros to be defined, undefined, and listed
3813 Show operating system information about processes.
3816 List the inferiors currently under GDB's control.
3819 Switch focus to inferior number NUM.
3822 Detach from inferior number NUM.
3825 Kill inferior number NUM.
3829 set spu stop-on-load
3830 show spu stop-on-load
3831 Control whether to stop for new SPE threads during Cell/B.E. debugging.
3833 set spu auto-flush-cache
3834 show spu auto-flush-cache
3835 Control whether to automatically flush the software-managed cache
3836 during Cell/B.E. debugging.
3838 set sh calling-convention
3839 show sh calling-convention
3840 Control the calling convention used when calling SH target functions.
3843 show debug timestamp
3844 Control display of timestamps with GDB debugging output.
3846 set disassemble-next-line
3847 show disassemble-next-line
3848 Control display of disassembled source lines or instructions when
3851 set remote noack-packet
3852 show remote noack-packet
3853 Set/show the use of remote protocol QStartNoAckMode packet. See above
3854 under "New remote packets."
3856 set remote query-attached-packet
3857 show remote query-attached-packet
3858 Control use of remote protocol `qAttached' (query-attached) packet.
3860 set remote read-siginfo-object
3861 show remote read-siginfo-object
3862 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
3865 set remote write-siginfo-object
3866 show remote write-siginfo-object
3867 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
3870 set remote reverse-continue
3871 show remote reverse-continue
3872 Control use of remote protocol 'bc' (reverse-continue) packet.
3874 set remote reverse-step
3875 show remote reverse-step
3876 Control use of remote protocol 'bs' (reverse-step) packet.
3878 set displaced-stepping
3879 show displaced-stepping
3880 Control displaced stepping mode. Displaced stepping is a way to
3881 single-step over breakpoints without removing them from the debuggee.
3882 Also known as "out-of-line single-stepping".
3885 show debug displaced
3886 Control display of debugging info for displaced stepping.
3888 maint set internal-error
3889 maint show internal-error
3890 Control what GDB does when an internal error is detected.
3892 maint set internal-warning
3893 maint show internal-warning
3894 Control what GDB does when an internal warning is detected.
3899 Use a wrapper program to launch programs for debugging.
3901 set multiple-symbols (all|ask|cancel)
3902 show multiple-symbols
3903 The value of this variable can be changed to adjust the debugger behavior
3904 when an expression or a breakpoint location contains an ambiguous symbol
3905 name (an overloaded function name, for instance).
3907 set breakpoint always-inserted
3908 show breakpoint always-inserted
3909 Keep breakpoints always inserted in the target, as opposed to inserting
3910 them when resuming the target, and removing them when the target stops.
3911 This option can improve debugger performance on slow remote targets.
3913 set arm fallback-mode (arm|thumb|auto)
3914 show arm fallback-mode
3915 set arm force-mode (arm|thumb|auto)
3917 These commands control how ARM GDB determines whether instructions
3918 are ARM or Thumb. The default for both settings is auto, which uses
3919 the current CPSR value for instructions without symbols; previous
3920 versions of GDB behaved as if "set arm fallback-mode arm".
3922 set disable-randomization
3923 show disable-randomization
3924 Standalone programs run with the virtual address space randomization enabled
3925 by default on some platforms. This option keeps the addresses stable across
3926 multiple debugging sessions.
3930 Control whether other threads are stopped or not when some thread hits
3935 Requests that asynchronous execution is enabled in the target, if available.
3936 In this case, it's possible to resume target in the background, and interact
3937 with GDB while the target is running. "show target-async" displays the
3938 current state of asynchronous execution of the target.
3940 set target-wide-charset
3941 show target-wide-charset
3942 The target-wide-charset is the name of the character set that GDB
3943 uses when printing characters whose type is wchar_t.
3945 set tcp auto-retry (on|off)
3947 set tcp connect-timeout
3948 show tcp connect-timeout
3949 These commands allow GDB to retry failed TCP connections to a remote stub
3950 with a specified timeout period; this is useful if the stub is launched
3951 in parallel with GDB but may not be ready to accept connections immediately.
3953 set libthread-db-search-path
3954 show libthread-db-search-path
3955 Control list of directories which GDB will search for appropriate
3958 set schedule-multiple (on|off)
3959 show schedule-multiple
3960 Allow GDB to resume all threads of all processes or only threads of
3961 the current process.
3965 Use more aggressive caching for accesses to the stack. This improves
3966 performance of remote debugging (particularly backtraces) without
3967 affecting correctness.
3969 set interactive-mode (on|off|auto)
3970 show interactive-mode
3971 Control whether GDB runs in interactive mode (on) or not (off).
3972 When in interactive mode, GDB waits for the user to answer all
3973 queries. Otherwise, GDB does not wait and assumes the default
3974 answer. When set to auto (the default), GDB determines which
3975 mode to use based on the stdin settings.
3980 For program forks, this is replaced by the new more generic `info
3981 inferiors' command. To list checkpoints, you can still use the
3982 `info checkpoints' command, which was an alias for the `info forks'
3986 Replaced by the new `inferior' command. To switch between
3987 checkpoints, you can still use the `restart' command, which was an
3988 alias for the `fork' command.
3991 This is removed, since some targets don't have a notion of
3992 processes. To switch between processes, you can still use the
3993 `inferior' command using GDB's own inferior number.
3996 For program forks, this is replaced by the new more generic `kill
3997 inferior' command. To delete a checkpoint, you can still use the
3998 `delete checkpoint' command, which was an alias for the `delete
4002 For program forks, this is replaced by the new more generic `detach
4003 inferior' command. To detach a checkpoint, you can still use the
4004 `detach checkpoint' command, which was an alias for the `detach
4007 * New native configurations
4009 x86/x86_64 Darwin i[34567]86-*-darwin*
4011 x86_64 MinGW x86_64-*-mingw*
4015 Lattice Mico32 lm32-*
4016 x86 DICOS i[34567]86-*-dicos*
4017 x86_64 DICOS x86_64-*-dicos*
4020 * The GDB remote stub, gdbserver, now supports x86 Windows CE
4021 (mingw32ce) debugging.
4027 These commands were actually not implemented on any target.
4029 *** Changes in GDB 6.8
4031 * New native configurations
4033 NetBSD/hppa hppa*-*netbsd*
4034 Xtensa GNU/Linux xtensa*-*-linux*
4038 NetBSD/hppa hppa*-*-netbsd*
4039 Xtensa GNU/Lunux xtensa*-*-linux*
4041 * Change in command line behavior -- corefiles vs. process ids.
4043 When the '-p NUMBER' or '--pid NUMBER' options are used, and
4044 attaching to process NUMBER fails, GDB no longer attempts to open a
4045 core file named NUMBER. Attaching to a program using the -c option
4046 is no longer supported. Instead, use the '-p' or '--pid' options.
4048 * GDB can now be built as a native debugger for debugging Windows x86
4049 (mingw32) Portable Executable (PE) programs.
4051 * Pending breakpoints no longer change their number when their address
4054 * GDB now supports breakpoints with multiple locations,
4055 including breakpoints on C++ constructors, inside C++ templates,
4056 and in inlined functions.
4058 * GDB's ability to debug optimized code has been improved. GDB more
4059 accurately identifies function bodies and lexical blocks that occupy
4060 more than one contiguous range of addresses.
4062 * Target descriptions can now describe registers for PowerPC.
4064 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
4065 registers on PowerPC targets.
4067 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
4068 targets even when the libthread_db library is not available.
4070 * The GDB remote stub, gdbserver, now supports the new file transfer
4071 commands (remote put, remote get, and remote delete).
4073 * The GDB remote stub, gdbserver, now supports run and attach in
4074 extended-remote mode.
4076 * hppa*64*-*-hpux11* target broken
4077 The debugger is unable to start a program and fails with the following
4078 error: "Error trying to get information about dynamic linker".
4079 The gdb-6.7 release is also affected.
4081 * GDB now supports the --enable-targets= configure option to allow
4082 building a single GDB executable that supports multiple remote
4083 target architectures.
4085 * GDB now supports debugging C and C++ programs which use the
4086 Decimal Floating Point extension. In addition, the PowerPC target
4087 now has a set of pseudo-registers to inspect decimal float values
4088 stored in two consecutive float registers.
4090 * The -break-insert MI command can optionally create pending
4093 * Improved support for debugging Ada
4094 Many improvements to the Ada language support have been made. These
4096 - Better support for Ada2005 interface types
4097 - Improved handling of arrays and slices in general
4098 - Better support for Taft-amendment types
4099 - The '{type} ADDRESS' expression is now allowed on the left hand-side
4101 - Improved command completion in Ada
4104 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
4109 set print frame-arguments (all|scalars|none)
4110 show print frame-arguments
4111 The value of this variable can be changed to control which argument
4112 values should be printed by the debugger when displaying a frame.
4117 Transfer files to and from a remote target, and delete remote files.
4124 Transfer files to and from a remote target, and delete remote files.
4126 * New remote packets
4133 Open, close, read, write, and delete files on the remote system.
4136 Attach to an existing process on the remote system, in extended-remote
4140 Run a new process on the remote system, in extended-remote mode.
4142 *** Changes in GDB 6.7
4144 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
4145 bfd, libiberty and opcodes, as revealed by static analysis donated by
4146 Coverity, Inc. (http://scan.coverity.com).
4148 * When looking up multiply-defined global symbols, GDB will now prefer the
4149 symbol definition in the current shared library if it was built using the
4150 -Bsymbolic linker option.
4152 * When the Text User Interface (TUI) is not configured, GDB will now
4153 recognize the -tui command-line option and print a message that the TUI
4156 * The GDB remote stub, gdbserver, now has lower overhead for high
4157 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
4159 * GDB for MIPS targets now autodetects whether a remote target provides
4160 32-bit or 64-bit register values.
4162 * Support for C++ member pointers has been improved.
4164 * GDB now understands XML target descriptions, which specify the
4165 target's overall architecture. GDB can read a description from
4166 a local file or over the remote serial protocol.
4168 * Vectors of single-byte data use a new integer type which is not
4169 automatically displayed as character or string data.
4171 * The /s format now works with the print command. It displays
4172 arrays of single-byte integers and pointers to single-byte integers
4175 * Target descriptions can now describe target-specific registers,
4176 for architectures which have implemented the support (currently
4177 only ARM, M68K, and MIPS).
4179 * GDB and the GDB remote stub, gdbserver, now support the XScale
4182 * The GDB remote stub, gdbserver, has been updated to support
4183 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
4184 has been rewritten to use the standard GDB remote protocol.
4186 * GDB can now step into C++ functions which are called through thunks.
4188 * GDB for the Cell/B.E. SPU now supports overlay debugging.
4190 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
4191 layout. It also supports a TextSeg= and DataSeg= response when only
4192 segment base addresses (rather than offsets) are available.
4194 * The /i format now outputs any trailing branch delay slot instructions
4195 immediately following the last instruction within the count specified.
4197 * The GDB remote protocol "T" stop reply packet now supports a
4198 "library" response. Combined with the new "qXfer:libraries:read"
4199 packet, this response allows GDB to debug shared libraries on targets
4200 where the operating system manages the list of loaded libraries (e.g.
4201 Windows and SymbianOS).
4203 * The GDB remote stub, gdbserver, now supports dynamic link libraries
4204 (DLLs) on Windows and Windows CE targets.
4206 * GDB now supports a faster verification that a .debug file matches its binary
4207 according to its build-id signature, if the signature is present.
4213 Enable or disable hardware flow control (RTS/CTS) on the serial port
4214 when debugging using remote targets.
4216 set mem inaccessible-by-default
4217 show mem inaccessible-by-default
4218 If the target supplies a memory map, for instance via the remote
4219 protocol's "qXfer:memory-map:read" packet, setting this variable
4220 prevents GDB from accessing memory outside the memory map. This
4221 is useful for targets with memory mapped registers or which react
4222 badly to accesses of unmapped address space.
4224 set breakpoint auto-hw
4225 show breakpoint auto-hw
4226 If the target supplies a memory map, for instance via the remote
4227 protocol's "qXfer:memory-map:read" packet, setting this variable
4228 lets GDB use hardware breakpoints automatically for memory regions
4229 where it can not use software breakpoints. This covers both the
4230 "break" command and internal breakpoints used for other commands
4231 including "next" and "finish".
4234 catch exception unhandled
4235 Stop the program execution when Ada exceptions are raised.
4238 Stop the program execution when an Ada assertion failed.
4242 Set an alternate system root for target files. This is a more
4243 general version of "set solib-absolute-prefix", which is now
4244 an alias to "set sysroot".
4247 Provide extended SPU facility status information. This set of
4248 commands is available only when debugging the Cell/B.E. SPU
4251 * New native configurations
4253 OpenBSD/sh sh*-*openbsd*
4256 unset tdesc filename
4258 Use the specified local file as an XML target description, and do
4259 not query the target for its built-in description.
4263 OpenBSD/sh sh*-*-openbsd*
4264 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
4265 Toshiba Media Processor mep-elf
4267 * New remote packets
4270 Ignore the specified signals; pass them directly to the debugged program
4271 without stopping other threads or reporting them to GDB.
4273 qXfer:features:read:
4274 Read an XML target description from the target, which describes its
4279 Read or write contents of an spufs file on the target system. These
4280 packets are available only on the Cell/B.E. SPU architecture.
4282 qXfer:libraries:read:
4283 Report the loaded shared libraries. Combined with new "T" packet
4284 response, this packet allows GDB to debug shared libraries on
4285 targets where the operating system manages the list of loaded
4286 libraries (e.g. Windows and SymbianOS).
4290 Support for these obsolete configurations has been removed.
4298 i[34567]86-*-lynxos*
4299 i[34567]86-*-netware*
4300 i[34567]86-*-sco3.2v5*
4301 i[34567]86-*-sco3.2v4*
4303 i[34567]86-*-sysv4.2*
4306 i[34567]86-*-unixware2*
4307 i[34567]86-*-unixware*
4316 * Other removed features
4323 Various m68k-only ROM monitors.
4330 Various Renesas ROM monitors and debugging interfaces for SH and
4335 Support for a Macraigor serial interface to on-chip debugging.
4336 GDB does not directly support the newer parallel or USB
4341 A debug information format. The predecessor to DWARF 2 and
4342 DWARF 3, which are still supported.
4344 Support for the HP aCC compiler on HP-UX/PA-RISC
4346 SOM-encapsulated symbolic debugging information, automatic
4347 invocation of pxdb, and the aCC custom C++ ABI. This does not
4348 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
4349 with aCC can still be debugged on an assembly level.
4351 MIPS ".pdr" sections
4353 A MIPS-specific format used to describe stack frame layout
4354 in debugging information.
4358 GDB could work with an older version of Guile to debug
4359 the interpreter and Scheme programs running in it.
4361 set mips stack-arg-size
4362 set mips saved-gpreg-size
4364 Use "set mips abi" to control parameter passing for MIPS.
4366 *** Changes in GDB 6.6
4371 Cell Broadband Engine SPU spu-elf
4373 * GDB can now be configured as a cross-debugger targeting native Windows
4374 (mingw32) or Cygwin. It can communicate with a remote debugging stub
4375 running on a Windows system over TCP/IP to debug Windows programs.
4377 * The GDB remote stub, gdbserver, has been updated to support Windows and
4378 Cygwin debugging. Both single-threaded and multi-threaded programs are
4381 * The "set trust-readonly-sections" command works again. This command was
4382 broken in GDB 6.3, 6.4, and 6.5.
4384 * The "load" command now supports writing to flash memory, if the remote
4385 stub provides the required support.
4387 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
4388 longer requires symbolic debug information (e.g. DWARF-2).
4393 unset substitute-path
4394 show substitute-path
4395 Manage a list of substitution rules that GDB uses to rewrite the name
4396 of the directories where the sources are located. This can be useful
4397 for instance when the sources were moved to a different location
4398 between compilation and debugging.
4402 Print each CLI command as it is executed. Each command is prefixed with
4403 a number of `+' symbols representing the nesting depth.
4404 The source command now has a `-v' option to enable the same feature.
4408 The ARM Demon monitor support (RDP protocol, "target rdp").
4410 Kernel Object Display, an embedded debugging feature which only worked with
4411 an obsolete version of Cisco IOS.
4413 The 'set download-write-size' and 'show download-write-size' commands.
4415 * New remote packets
4418 Tell a stub about GDB client features, and request remote target features.
4419 The first feature implemented is PacketSize, which allows the target to
4420 specify the size of packets it can handle - to minimize the number of
4421 packets required and improve performance when connected to a remote
4425 Fetch an OS auxilliary vector from the remote stub. This packet is a
4426 more efficient replacement for qPart:auxv:read.
4428 qXfer:memory-map:read:
4429 Fetch a memory map from the remote stub, including information about
4430 RAM, ROM, and flash memory devices.
4435 Erase and program a flash memory device.
4437 * Removed remote packets
4440 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
4441 used it, and only gdbserver implemented it.
4443 *** Changes in GDB 6.5
4447 Renesas M32C/M16C m32c-elf
4449 Morpho Technologies ms1 ms1-elf
4453 init-if-undefined Initialize a convenience variable, but
4454 only if it doesn't already have a value.
4456 The following commands are presently only implemented for native GNU/Linux:
4458 checkpoint Save a snapshot of the program state.
4460 restart <n> Return the program state to a
4461 previously saved state.
4463 info checkpoints List currently saved checkpoints.
4465 delete-checkpoint <n> Delete a previously saved checkpoint.
4467 set|show detach-on-fork Tell gdb whether to detach from a newly
4468 forked process, or to keep debugging it.
4470 info forks List forks of the user program that
4471 are available to be debugged.
4473 fork <n> Switch to debugging one of several
4474 forks of the user program that are
4475 available to be debugged.
4477 delete-fork <n> Delete a fork from the list of forks
4478 that are available to be debugged (and
4479 kill the forked process).
4481 detach-fork <n> Delete a fork from the list of forks
4482 that are available to be debugged (and
4483 allow the process to continue).
4487 Morpho Technologies ms2 ms1-elf
4489 * Improved Windows host support
4491 GDB now builds as a cross debugger hosted on i686-mingw32, including
4492 native console support, and remote communications using either
4493 network sockets or serial ports.
4495 * Improved Modula-2 language support
4497 GDB can now print most types in the Modula-2 syntax. This includes:
4498 basic types, set types, record types, enumerated types, range types,
4499 pointer types and ARRAY types. Procedure var parameters are correctly
4500 printed and hexadecimal addresses and character constants are also
4501 written in the Modula-2 syntax. Best results can be obtained by using
4502 GNU Modula-2 together with the -gdwarf-2 command line option.
4506 The ARM rdi-share module.
4508 The Netware NLM debug server.
4510 *** Changes in GDB 6.4
4512 * New native configurations
4514 OpenBSD/arm arm*-*-openbsd*
4515 OpenBSD/mips64 mips64-*-openbsd*
4519 Morpho Technologies ms1 ms1-elf
4521 * New command line options
4523 --batch-silent As for --batch, but totally silent.
4524 --return-child-result The debugger will exist with the same value
4525 the child (debugged) program exited with.
4526 --eval-command COMMAND, -ex COMMAND
4527 Execute a single GDB CLI command. This may be
4528 specified multiple times and in conjunction
4529 with the --command (-x) option.
4531 * Deprecated commands removed
4533 The following commands, that were deprecated in 2000, have been
4537 set|show arm disassembly-flavor set|show arm disassembler
4538 othernames set arm disassembler
4539 set|show remotedebug set|show debug remote
4540 set|show archdebug set|show debug arch
4541 set|show eventdebug set|show debug event
4544 * New BSD user-level threads support
4546 It is now possible to debug programs using the user-level threads
4547 library on OpenBSD and FreeBSD. Currently supported (target)
4550 FreeBSD/amd64 x86_64-*-freebsd*
4551 FreeBSD/i386 i386-*-freebsd*
4552 OpenBSD/i386 i386-*-openbsd*
4554 Note that the new kernel threads libraries introduced in FreeBSD 5.x
4555 are not yet supported.
4557 * New support for Matsushita MN10300 w/sim added
4558 (Work in progress). mn10300-elf.
4560 * REMOVED configurations and files
4562 VxWorks and the XDR protocol *-*-vxworks
4563 Motorola MCORE mcore-*-*
4564 National Semiconductor NS32000 ns32k-*-*
4566 * New "set print array-indexes" command
4568 After turning this setting "on", GDB prints the index of each element
4569 when displaying arrays. The default is "off" to preserve the previous
4572 * VAX floating point support
4574 GDB now supports the not-quite-ieee VAX F and D floating point formats.
4576 * User-defined command support
4578 In addition to using $arg0..$arg9 for argument passing, it is now possible
4579 to use $argc to determine now many arguments have been passed. See the
4580 section on user-defined commands in the user manual for more information.
4582 *** Changes in GDB 6.3:
4584 * New command line option
4586 GDB now accepts -l followed by a number to set the timeout for remote
4589 * GDB works with GCC -feliminate-dwarf2-dups
4591 GDB now supports a more compact representation of DWARF-2 debug
4592 information using DW_FORM_ref_addr references. These are produced
4593 by GCC with the option -feliminate-dwarf2-dups and also by some
4594 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
4595 to use -feliminate-dwarf2-dups.
4597 * Internationalization
4599 When supported by the host system, GDB will be built with
4600 internationalization (libintl). The task of marking up the sources is
4601 continued, we're looking forward to our first translation.
4605 Initial support for debugging programs compiled with the GNAT
4606 implementation of the Ada programming language has been integrated
4607 into GDB. In this release, support is limited to expression evaluation.
4609 * New native configurations
4611 GNU/Linux/m32r m32r-*-linux-gnu
4615 GDB's remote protocol now includes support for the 'p' packet. This
4616 packet is used to fetch individual registers from a remote inferior.
4618 * END-OF-LIFE registers[] compatibility module
4620 GDB's internal register infrastructure has been completely rewritten.
4621 The new infrastructure making possible the implementation of key new
4622 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
4625 GDB 6.3 will be the last release to include the the registers[]
4626 compatibility module that allowed out-of-date configurations to
4627 continue to work. This change directly impacts the following
4637 powerpc bdm protocol
4639 Unless there is activity to revive these configurations, they will be
4640 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
4642 * OBSOLETE configurations and files
4644 Configurations that have been declared obsolete in this release have
4645 been commented out. Unless there is activity to revive these
4646 configurations, the next release of GDB will have their sources
4647 permanently REMOVED.
4656 *** Changes in GDB 6.2.1:
4658 * MIPS `break main; run' gave an heuristic-fence-post warning
4660 When attempting to run even a simple program, a warning about
4661 heuristic-fence-post being hit would be reported. This problem has
4664 * MIPS IRIX 'long double' crashed GDB
4666 When examining a long double variable, GDB would get a segmentation
4667 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
4668 IRIX long double values).
4672 A bug in the VAX stack code was causing problems with the "next"
4673 command. This problem has been fixed.
4675 *** Changes in GDB 6.2:
4677 * Fix for ``many threads''
4679 On GNU/Linux systems that use the NPTL threads library, a program
4680 rapidly creating and deleting threads would confuse GDB leading to the
4683 ptrace: No such process.
4684 thread_db_get_info: cannot get thread info: generic error
4686 This problem has been fixed.
4688 * "-async" and "-noasync" options removed.
4690 Support for the broken "-noasync" option has been removed (it caused
4693 * New ``start'' command.
4695 This command runs the program until the begining of the main procedure.
4697 * New BSD Kernel Data Access Library (libkvm) interface
4699 Using ``target kvm'' it is now possible to debug kernel core dumps and
4700 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
4701 platforms. Currently supported (native-only) configurations are:
4703 FreeBSD/amd64 x86_64-*-freebsd*
4704 FreeBSD/i386 i?86-*-freebsd*
4705 NetBSD/i386 i?86-*-netbsd*
4706 NetBSD/m68k m68*-*-netbsd*
4707 NetBSD/sparc sparc-*-netbsd*
4708 OpenBSD/amd64 x86_64-*-openbsd*
4709 OpenBSD/i386 i?86-*-openbsd*
4710 OpenBSD/m68k m68*-openbsd*
4711 OpenBSD/sparc sparc-*-openbsd*
4713 * Signal trampoline code overhauled
4715 Many generic problems with GDB's signal handling code have been fixed.
4716 These include: backtraces through non-contiguous stacks; recognition
4717 of sa_sigaction signal trampolines; backtrace from a NULL pointer
4718 call; backtrace through a signal trampoline; step into and out of
4719 signal handlers; and single-stepping in the signal trampoline.
4721 Please note that kernel bugs are a limiting factor here. These
4722 features have been shown to work on an s390 GNU/Linux system that
4723 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
4725 * Cygwin support for DWARF 2 added.
4727 * New native configurations
4729 GNU/Linux/hppa hppa*-*-linux*
4730 OpenBSD/hppa hppa*-*-openbsd*
4731 OpenBSD/m68k m68*-*-openbsd*
4732 OpenBSD/m88k m88*-*-openbsd*
4733 OpenBSD/powerpc powerpc-*-openbsd*
4734 NetBSD/vax vax-*-netbsd*
4735 OpenBSD/vax vax-*-openbsd*
4737 * END-OF-LIFE frame compatibility module
4739 GDB's internal frame infrastructure has been completely rewritten.
4740 The new infrastructure making it possible to support key new features
4741 including DWARF 2 Call Frame Information. To aid in the task of
4742 migrating old configurations to this new infrastructure, a
4743 compatibility module, that allowed old configurations to continue to
4744 work, was also included.
4746 GDB 6.2 will be the last release to include this frame compatibility
4747 module. This change directly impacts the following configurations:
4757 Unless there is activity to revive these configurations, they will be
4758 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
4760 * REMOVED configurations and files
4762 Sun 3, running SunOS 3 m68*-*-sunos3*
4763 Sun 3, running SunOS 4 m68*-*-sunos4*
4764 Sun 2, running SunOS 3 m68000-*-sunos3*
4765 Sun 2, running SunOS 4 m68000-*-sunos4*
4766 Motorola 680x0 running LynxOS m68*-*-lynxos*
4767 AT&T 3b1/Unix pc m68*-att-*
4768 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4769 decstation mips-dec-* mips-little-*
4770 riscos mips-*-riscos* mips-*-sysv*
4771 sonymips mips-sony-*
4772 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4774 *** Changes in GDB 6.1.1:
4776 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
4778 The TUI (Text-mode User Interface) is now built as part of a default
4779 GDB configuration. It is enabled by either selecting the TUI with the
4780 command line option "-i=tui" or by running the separate "gdbtui"
4781 program. For more information on the TUI, see the manual "Debugging
4784 * Pending breakpoint support (also included in GDB 6.1)
4786 Support has been added to allow you to specify breakpoints in shared
4787 libraries that have not yet been loaded. If a breakpoint location
4788 cannot be found, and the "breakpoint pending" option is set to auto,
4789 GDB queries you if you wish to make the breakpoint pending on a future
4790 shared-library load. If and when GDB resolves the breakpoint symbol,
4791 the pending breakpoint is removed as one or more regular breakpoints
4794 Pending breakpoints are very useful for GCJ Java debugging.
4796 * Fixed ISO-C build problems
4798 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
4799 non ISO-C code that stopped them being built using a more strict ISO-C
4800 compiler (e.g., IBM's C compiler).
4802 * Fixed build problem on IRIX 5
4804 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
4805 wasn't able to compile compile on an IRIX 5 system.
4807 * Added execute permission to gdb/gdbserver/configure
4809 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
4810 permission. This bug would cause configure to fail on a number of
4811 systems (Solaris, IRIX). Ref: server/519.
4813 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
4815 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
4816 has been updated to use constant array sizes.
4818 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
4820 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
4821 its generated DWARF Call Frame Info. This encoding was causing GDB to
4822 panic, that panic has been fixed. Ref: gdb/1628.
4824 * Fixed a problem when examining parameters in shared library code.
4826 When examining parameters in optimized shared library code generated
4827 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
4828 not available''. GDB now correctly displays the variable's value.
4830 *** Changes in GDB 6.1:
4832 * Removed --with-mmalloc
4834 Support for the mmalloc memory manager has been removed, as it
4835 conflicted with the internal gdb byte cache.
4837 * Changes in AMD64 configurations
4839 The AMD64 target now includes the %cs and %ss registers. As a result
4840 the AMD64 remote protocol has changed; this affects the floating-point
4841 and SSE registers. If you rely on those registers for your debugging,
4842 you should upgrade gdbserver on the remote side.
4844 * Revised SPARC target
4846 The SPARC target has been completely revised, incorporating the
4847 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
4848 support for LynxOS and SunOS 4 has been dropped. Calling functions
4849 from within GDB on operating systems with a non-executable stack
4850 (Solaris, OpenBSD) now works.
4854 GDB has a new C++ demangler which does a better job on the mangled
4855 names generated by current versions of g++. It also runs faster, so
4856 with this and other changes gdb should now start faster on large C++
4859 * DWARF 2 Location Expressions
4861 GDB support for location expressions has been extended to support function
4862 arguments and frame bases. Older versions of GDB could crash when they
4865 * C++ nested types and namespaces
4867 GDB's support for nested types and namespaces in C++ has been
4868 improved, especially if you use the DWARF 2 debugging format. (This
4869 is the default for recent versions of GCC on most platforms.)
4870 Specifically, if you have a class "Inner" defined within a class or
4871 namespace "Outer", then GDB realizes that the class's name is
4872 "Outer::Inner", not simply "Inner". This should greatly reduce the
4873 frequency of complaints about not finding RTTI symbols. In addition,
4874 if you are stopped at inside of a function defined within a namespace,
4875 GDB modifies its name lookup accordingly.
4877 * New native configurations
4879 NetBSD/amd64 x86_64-*-netbsd*
4880 OpenBSD/amd64 x86_64-*-openbsd*
4881 OpenBSD/alpha alpha*-*-openbsd*
4882 OpenBSD/sparc sparc-*-openbsd*
4883 OpenBSD/sparc64 sparc64-*-openbsd*
4885 * New debugging protocols
4887 M32R with SDI protocol m32r-*-elf*
4889 * "set prompt-escape-char" command deleted.
4891 The command "set prompt-escape-char" has been deleted. This command,
4892 and its very obscure effet on GDB's prompt, was never documented,
4893 tested, nor mentioned in the NEWS file.
4895 * OBSOLETE configurations and files
4897 Configurations that have been declared obsolete in this release have
4898 been commented out. Unless there is activity to revive these
4899 configurations, the next release of GDB will have their sources
4900 permanently REMOVED.
4902 Sun 3, running SunOS 3 m68*-*-sunos3*
4903 Sun 3, running SunOS 4 m68*-*-sunos4*
4904 Sun 2, running SunOS 3 m68000-*-sunos3*
4905 Sun 2, running SunOS 4 m68000-*-sunos4*
4906 Motorola 680x0 running LynxOS m68*-*-lynxos*
4907 AT&T 3b1/Unix pc m68*-att-*
4908 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
4909 decstation mips-dec-* mips-little-*
4910 riscos mips-*-riscos* mips-*-sysv*
4911 sonymips mips-sony-*
4912 sysv mips*-*-sysv4* (IRIX 5/6 not included)
4914 * REMOVED configurations and files
4916 SGI Irix-4.x mips-sgi-irix4 or iris4
4917 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
4918 Z8000 simulator z8k-zilog-none or z8ksim
4919 Matsushita MN10200 w/simulator mn10200-*-*
4920 H8/500 simulator h8500-hitachi-hms or h8500hms
4921 HP/PA running BSD hppa*-*-bsd*
4922 HP/PA running OSF/1 hppa*-*-osf*
4923 HP/PA Pro target hppa*-*-pro*
4924 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
4925 386BSD i[3456]86-*-bsd*
4926 Sequent family i[3456]86-sequent-sysv4*
4927 i[3456]86-sequent-sysv*
4928 i[3456]86-sequent-bsd*
4929 SPARC running LynxOS sparc-*-lynxos*
4930 SPARC running SunOS 4 sparc-*-sunos4*
4931 Tsqware Sparclet sparclet-*-*
4932 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4934 *** Changes in GDB 6.0:
4938 Support for debugging the Objective-C programming language has been
4939 integrated into GDB.
4941 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
4943 DWARF 2's Call Frame Information makes available compiler generated
4944 information that more exactly describes the program's run-time stack.
4945 By using this information, GDB is able to provide more robust stack
4948 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
4949 have been updated to use a new backtrace mechanism which includes
4950 DWARF 2 CFI support.
4954 GDB's remote protocol has been extended to include support for hosted
4955 file I/O (where the remote target uses GDB's file system). See GDB's
4956 remote protocol documentation for details.
4958 * All targets using the new architecture framework.
4960 All of GDB's targets have been updated to use the new internal
4961 architecture framework. The way is now open for future GDB releases
4962 to include cross-architecture native debugging support (i386 on amd64,
4965 * GNU/Linux's Thread Local Storage (TLS)
4967 GDB now includes support for for the GNU/Linux implementation of
4968 per-thread variables.
4970 * GNU/Linux's Native POSIX Thread Library (NPTL)
4972 GDB's thread code has been updated to work with either the new
4973 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
4975 * Separate debug info.
4977 GDB, in conjunction with BINUTILS, now supports a mechanism for
4978 automatically loading debug information from a separate file. Instead
4979 of shipping full debug and non-debug versions of system libraries,
4980 system integrators can now instead ship just the stripped libraries
4981 and optional debug files.
4983 * DWARF 2 Location Expressions
4985 DWARF 2 Location Expressions allow the compiler to more completely
4986 describe the location of variables (even in optimized code) to the
4989 GDB now includes preliminary support for location expressions (support
4990 for DW_OP_piece is still missing).
4994 A number of long standing bugs that caused GDB to die while starting a
4995 Java application have been fixed. GDB's Java support is now
4996 considered "useable".
4998 * GNU/Linux support for fork, vfork, and exec.
5000 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
5001 commands are now implemented for GNU/Linux. They require a 2.5.x or later
5004 * GDB supports logging output to a file
5006 There are two new commands, "set logging" and "show logging", which can be
5007 used to capture GDB's output to a file.
5009 * The meaning of "detach" has changed for gdbserver
5011 The "detach" command will now resume the application, as documented. To
5012 disconnect from gdbserver and leave it stopped, use the new "disconnect"
5015 * d10v, m68hc11 `regs' command deprecated
5017 The `info registers' command has been updated so that it displays the
5018 registers using a format identical to the old `regs' command.
5022 A new command, "maint set profile on/off", has been added. This command can
5023 be used to enable or disable profiling while running GDB, to profile a
5024 session or a set of commands. In addition there is a new configure switch,
5025 "--enable-profiling", which will cause GDB to be compiled with profiling
5026 data, for more informative profiling results.
5028 * Default MI syntax changed to "mi2".
5030 The default MI (machine interface) syntax, enabled by the command line
5031 option "-i=mi", has been changed to "mi2". The previous MI syntax,
5032 "mi1", can be enabled by specifying the option "-i=mi1".
5034 Support for the original "mi0" syntax (included in GDB 5.0) has been
5037 Fix for gdb/192: removed extraneous space when displaying frame level.
5038 Fix for gdb/672: update changelist is now output in mi list format.
5039 Fix for gdb/702: a -var-assign that updates the value now shows up
5040 in a subsequent -var-update.
5042 * New native configurations.
5044 FreeBSD/amd64 x86_64-*-freebsd*
5046 * Multi-arched targets.
5048 HP/PA HPUX11 hppa*-*-hpux*
5049 Renesas M32R/D w/simulator m32r-*-elf*
5051 * OBSOLETE configurations and files
5053 Configurations that have been declared obsolete in this release have
5054 been commented out. Unless there is activity to revive these
5055 configurations, the next release of GDB will have their sources
5056 permanently REMOVED.
5058 Z8000 simulator z8k-zilog-none or z8ksim
5059 Matsushita MN10200 w/simulator mn10200-*-*
5060 H8/500 simulator h8500-hitachi-hms or h8500hms
5061 HP/PA running BSD hppa*-*-bsd*
5062 HP/PA running OSF/1 hppa*-*-osf*
5063 HP/PA Pro target hppa*-*-pro*
5064 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
5065 Sequent family i[3456]86-sequent-sysv4*
5066 i[3456]86-sequent-sysv*
5067 i[3456]86-sequent-bsd*
5068 Tsqware Sparclet sparclet-*-*
5069 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
5071 * REMOVED configurations and files
5074 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5075 IBM AIX PS/2 i[3456]86-*-aix
5076 i386 running Mach 3.0 i[3456]86-*-mach3*
5077 i386 running Mach i[3456]86-*-mach*
5078 i386 running OSF/1 i[3456]86-*osf1mk*
5079 HP/Apollo 68k Family m68*-apollo*-sysv*,
5081 m68*-hp-bsd*, m68*-hp-hpux*
5082 Argonaut Risc Chip (ARC) arc-*-*
5083 Mitsubishi D30V d30v-*-*
5084 Fujitsu FR30 fr30-*-elf*
5085 OS/9000 i[34]86-*-os9k
5086 I960 with MON960 i960-*-coff
5088 * MIPS $fp behavior changed
5090 The convenience variable $fp, for the MIPS, now consistently returns
5091 the address of the current frame's base. Previously, depending on the
5092 context, $fp could refer to either $sp or the current frame's base
5093 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
5094 The GNU Source-Level Debugger''.
5096 *** Changes in GDB 5.3:
5098 * GNU/Linux shared library multi-threaded performance improved.
5100 When debugging a multi-threaded application on GNU/Linux, GDB now uses
5101 `/proc', in preference to `ptrace' for memory reads. This may result
5102 in an improvement in the start-up time of multi-threaded, shared
5103 library applications when run under GDB. One GDB user writes: ``loads
5104 shared libs like mad''.
5106 * ``gdbserver'' now supports multi-threaded applications on some targets
5108 Support for debugging multi-threaded applications which use
5109 the GNU/Linux LinuxThreads package has been added for
5110 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
5111 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
5113 * GDB now supports C/C++ preprocessor macros.
5115 GDB now expands preprocessor macro invocations in C/C++ expressions,
5116 and provides various commands for showing macro definitions and how
5119 The new command `macro expand EXPRESSION' expands any macro
5120 invocations in expression, and shows the result.
5122 The new command `show macro MACRO-NAME' shows the definition of the
5123 macro named MACRO-NAME, and where it was defined.
5125 Most compilers don't include information about macros in the debugging
5126 information by default. In GCC 3.1, for example, you need to compile
5127 your program with the options `-gdwarf-2 -g3'. If the macro
5128 information is present in the executable, GDB will read it.
5130 * Multi-arched targets.
5132 DEC Alpha (partial) alpha*-*-*
5133 DEC VAX (partial) vax-*-*
5135 National Semiconductor NS32000 (partial) ns32k-*-*
5136 Motorola 68000 (partial) m68k-*-*
5137 Motorola MCORE mcore-*-*
5141 Fujitsu FRV architecture added by Red Hat frv*-*-*
5144 * New native configurations
5146 Alpha NetBSD alpha*-*-netbsd*
5147 SH NetBSD sh*-*-netbsdelf*
5148 MIPS NetBSD mips*-*-netbsd*
5149 UltraSPARC NetBSD sparc64-*-netbsd*
5151 * OBSOLETE configurations and files
5153 Configurations that have been declared obsolete in this release have
5154 been commented out. Unless there is activity to revive these
5155 configurations, the next release of GDB will have their sources
5156 permanently REMOVED.
5158 Mitsubishi D30V d30v-*-*
5159 OS/9000 i[34]86-*-os9k
5160 IBM AIX PS/2 i[3456]86-*-aix
5161 Fujitsu FR30 fr30-*-elf*
5162 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5163 Argonaut Risc Chip (ARC) arc-*-*
5164 i386 running Mach 3.0 i[3456]86-*-mach3*
5165 i386 running Mach i[3456]86-*-mach*
5166 i386 running OSF/1 i[3456]86-*osf1mk*
5167 HP/Apollo 68k Family m68*-apollo*-sysv*,
5169 m68*-hp-bsd*, m68*-hp-hpux*
5170 I960 with MON960 i960-*-coff
5172 * OBSOLETE languages
5174 CHILL, a Pascal like language used by telecommunications companies.
5176 * REMOVED configurations and files
5178 AMD 29k family via UDI a29k-amd-udi, udi29k
5179 A29K VxWorks a29k-*-vxworks
5180 AMD 29000 embedded, using EBMON a29k-none-none
5181 AMD 29000 embedded with COFF a29k-none-coff
5182 AMD 29000 embedded with a.out a29k-none-aout
5184 testsuite/gdb.hp/gdb.threads-hp/ directory
5186 * New command "set max-user-call-depth <nnn>"
5188 This command allows the user to limit the call depth of user-defined
5189 commands. The default is 1024.
5191 * Changes in FreeBSD/i386 native debugging.
5193 Support for the "generate-core-file" has been added.
5195 * New commands "dump", "append", and "restore".
5197 These commands allow data to be copied from target memory
5198 to a bfd-format or binary file (dump and append), and back
5199 from a file into memory (restore).
5201 * Improved "next/step" support on multi-processor Alpha Tru64.
5203 The previous single-step mechanism could cause unpredictable problems,
5204 including the random appearance of SIGSEGV or SIGTRAP signals. The use
5205 of a software single-step mechanism prevents this.
5207 *** Changes in GDB 5.2.1:
5215 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
5216 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
5217 Fix, by Joel Brobecker imported from mainline.
5219 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
5220 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
5221 Fix, by Fred Fish, imported from mainline.
5223 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
5224 Surprisingly enough, it works now.
5225 By Michal Ludvig, imported from mainline.
5227 i386 hardware watchpoint support:
5228 avoid misses on second run for some targets.
5229 By Pierre Muller, imported from mainline.
5231 *** Changes in GDB 5.2:
5233 * New command "set trust-readonly-sections on[off]".
5235 This command is a hint that tells gdb that read-only sections
5236 really are read-only (ie. that their contents will not change).
5237 In this mode, gdb will go to the object file rather than the
5238 target to read memory from read-only sections (such as ".text").
5239 This can be a significant performance improvement on some
5240 (notably embedded) targets.
5242 * New command "generate-core-file" (or "gcore").
5244 This new gdb command allows the user to drop a core file of the child
5245 process state at any time. So far it's been implemented only for
5246 GNU/Linux and Solaris, but should be relatively easily ported to other
5247 hosts. Argument is core file name (defaults to core.<pid>).
5249 * New command line option
5251 GDB now accepts --pid or -p followed by a process id.
5253 * Change in command line behavior -- corefiles vs. process ids.
5255 There is a subtle behavior in the way in which GDB handles
5256 command line arguments. The first non-flag argument is always
5257 a program to debug, but the second non-flag argument may either
5258 be a corefile or a process id. Previously, GDB would attempt to
5259 open the second argument as a corefile, and if that failed, would
5260 issue a superfluous error message and then attempt to attach it as
5261 a process. Now, if the second argument begins with a non-digit,
5262 it will be treated as a corefile. If it begins with a digit,
5263 GDB will attempt to attach it as a process, and if no such process
5264 is found, will then attempt to open it as a corefile.
5266 * Changes in ARM configurations.
5268 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
5269 configuration is fully multi-arch.
5271 * New native configurations
5273 ARM NetBSD arm*-*-netbsd*
5274 x86 OpenBSD i[3456]86-*-openbsd*
5275 AMD x86-64 running GNU/Linux x86_64-*-linux-*
5276 Sparc64 running FreeBSD sparc64-*-freebsd*
5280 Sanyo XStormy16 xstormy16-elf
5282 * OBSOLETE configurations and files
5284 Configurations that have been declared obsolete in this release have
5285 been commented out. Unless there is activity to revive these
5286 configurations, the next release of GDB will have their sources
5287 permanently REMOVED.
5289 AMD 29k family via UDI a29k-amd-udi, udi29k
5290 A29K VxWorks a29k-*-vxworks
5291 AMD 29000 embedded, using EBMON a29k-none-none
5292 AMD 29000 embedded with COFF a29k-none-coff
5293 AMD 29000 embedded with a.out a29k-none-aout
5295 testsuite/gdb.hp/gdb.threads-hp/ directory
5297 * REMOVED configurations and files
5299 TI TMS320C80 tic80-*-*
5301 PowerPC Solaris powerpcle-*-solaris*
5302 PowerPC Windows NT powerpcle-*-cygwin32
5303 PowerPC Netware powerpc-*-netware*
5304 Harris/CXUX m88k m88*-harris-cxux*
5305 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5306 ns32k-utek-sysv* ns32k-utek-*
5307 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5308 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5309 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5310 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5311 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
5313 * Changes to command line processing
5315 The new `--args' feature can be used to specify command-line arguments
5316 for the inferior from gdb's command line.
5318 * Changes to key bindings
5320 There is a new `operate-and-get-next' function bound to `C-o'.
5322 *** Changes in GDB 5.1.1
5324 Fix compile problem on DJGPP.
5326 Fix a problem with floating-point registers on the i386 being
5329 Fix to stop GDB crashing on .debug_str debug info.
5331 Numerous documentation fixes.
5333 Numerous testsuite fixes.
5335 *** Changes in GDB 5.1:
5337 * New native configurations
5339 Alpha FreeBSD alpha*-*-freebsd*
5340 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
5341 MIPS GNU/Linux mips*-*-linux*
5342 MIPS SGI Irix 6.x mips*-sgi-irix6*
5343 ia64 AIX ia64-*-aix*
5344 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
5348 Motorola 68HC11 and 68HC12 m68hc11-elf
5350 UltraSparc running GNU/Linux sparc64-*-linux*
5352 * OBSOLETE configurations and files
5354 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
5355 Harris/CXUX m88k m88*-harris-cxux*
5356 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
5357 ns32k-utek-sysv* ns32k-utek-*
5358 TI TMS320C80 tic80-*-*
5360 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
5361 PowerPC Solaris powerpcle-*-solaris*
5362 PowerPC Windows NT powerpcle-*-cygwin32
5363 PowerPC Netware powerpc-*-netware*
5364 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
5365 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
5366 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
5367 Apple Macintosh (MPW) host N/A
5369 stuff.c (Program to stuff files into a specially prepared space in kdb)
5370 kdb-start.c (Main loop for the standalone kernel debugger)
5372 Configurations that have been declared obsolete in this release have
5373 been commented out. Unless there is activity to revive these
5374 configurations, the next release of GDB will have their sources
5375 permanently REMOVED.
5377 * REMOVED configurations and files
5379 Altos 3068 m68*-altos-*
5380 Convex c1-*-*, c2-*-*
5382 ARM RISCix arm-*-* (as host)
5386 * GDB has been converted to ISO C.
5388 GDB's source code has been converted to ISO C. In particular, the
5389 sources are fully protoized, and rely on standard headers being
5394 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
5396 * The MI enabled by default.
5398 The new machine oriented interface (MI) introduced in GDB 5.0 has been
5399 revised and enabled by default. Packages which use GDB as a debugging
5400 engine behind a UI or another front end are encouraged to switch to
5401 using the GDB/MI interface, instead of the old annotations interface
5402 which is now deprecated.
5404 * Support for debugging Pascal programs.
5406 GDB now includes support for debugging Pascal programs. The following
5407 main features are supported:
5409 - Pascal-specific data types such as sets;
5411 - automatic recognition of Pascal sources based on file-name
5414 - Pascal-style display of data types, variables, and functions;
5416 - a Pascal expression parser.
5418 However, some important features are not yet supported.
5420 - Pascal string operations are not supported at all;
5422 - there are some problems with boolean types;
5424 - Pascal type hexadecimal constants are not supported
5425 because they conflict with the internal variables format;
5427 - support for Pascal objects and classes is not full yet;
5429 - unlike Pascal, GDB is case-sensitive for symbol names.
5431 * Changes in completion.
5433 Commands such as `shell', `run' and `set args', which pass arguments
5434 to inferior programs, now complete on file names, similar to what
5435 users expect at the shell prompt.
5437 Commands which accept locations, such as `disassemble', `print',
5438 `breakpoint', `until', etc. now complete on filenames as well as
5439 program symbols. Thus, if you type "break foob TAB", and the source
5440 files linked into the programs include `foobar.c', that file name will
5441 be one of the candidates for completion. However, file names are not
5442 considered for completion after you typed a colon that delimits a file
5443 name from a name of a function in that file, as in "break foo.c:bar".
5445 `set demangle-style' completes on available demangling styles.
5447 * New platform-independent commands:
5449 It is now possible to define a post-hook for a command as well as a
5450 hook that runs before the command. For more details, see the
5451 documentation of `hookpost' in the GDB manual.
5453 * Changes in GNU/Linux native debugging.
5455 Support for debugging multi-threaded programs has been completely
5456 revised for all platforms except m68k and sparc. You can now debug as
5457 many threads as your system allows you to have.
5459 Attach/detach is supported for multi-threaded programs.
5461 Support for SSE registers was added for x86. This doesn't work for
5462 multi-threaded programs though.
5464 * Changes in MIPS configurations.
5466 Multi-arch support is enabled for all MIPS configurations.
5468 GDB can now be built as native debugger on SGI Irix 6.x systems for
5469 debugging n32 executables. (Debugging 64-bit executables is not yet
5472 * Unified support for hardware watchpoints in all x86 configurations.
5474 Most (if not all) native x86 configurations support hardware-assisted
5475 breakpoints and watchpoints in a unified manner. This support
5476 implements debug register sharing between watchpoints, which allows to
5477 put a virtually infinite number of watchpoints on the same address,
5478 and also supports watching regions up to 16 bytes with several debug
5481 The new maintenance command `maintenance show-debug-regs' toggles
5482 debugging print-outs in functions that insert, remove, and test
5483 watchpoints and hardware breakpoints.
5485 * Changes in the DJGPP native configuration.
5487 New command ``info dos sysinfo'' displays assorted information about
5488 the CPU, OS, memory, and DPMI server.
5490 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
5491 display information about segment descriptors stored in GDT, LDT, and
5494 New commands ``info dos pde'' and ``info dos pte'' display entries
5495 from Page Directory and Page Tables (for now works with CWSDPMI only).
5496 New command ``info dos address-pte'' displays the Page Table entry for
5497 a given linear address.
5499 GDB can now pass command lines longer than 126 characters to the
5500 program being debugged (requires an update to the libdbg.a library
5501 which is part of the DJGPP development kit).
5503 DWARF2 debug info is now supported.
5505 It is now possible to `step' and `next' through calls to `longjmp'.
5507 * Changes in documentation.
5509 All GDB documentation was converted to GFDL, the GNU Free
5510 Documentation License.
5512 Tracepoints-related commands are now fully documented in the GDB
5515 TUI, the Text-mode User Interface, is now documented in the manual.
5517 Tracepoints-related commands are now fully documented in the GDB
5520 The "GDB Internals" manual now has an index. It also includes
5521 documentation of `ui_out' functions, GDB coding standards, x86
5522 hardware watchpoints, and memory region attributes.
5524 * GDB's version number moved to ``version.in''
5526 The Makefile variable VERSION has been replaced by the file
5527 ``version.in''. People creating GDB distributions should update the
5528 contents of this file.
5532 GUD support is now a standard part of the EMACS distribution.
5534 *** Changes in GDB 5.0:
5536 * Improved support for debugging FP programs on x86 targets
5538 Unified and much-improved support for debugging floating-point
5539 programs on all x86 targets. In particular, ``info float'' now
5540 displays the FP registers in the same format on all x86 targets, with
5541 greater level of detail.
5543 * Improvements and bugfixes in hardware-assisted watchpoints
5545 It is now possible to watch array elements, struct members, and
5546 bitfields with hardware-assisted watchpoints. Data-read watchpoints
5547 on x86 targets no longer erroneously trigger when the address is
5550 * Improvements in the native DJGPP version of GDB
5552 The distribution now includes all the scripts and auxiliary files
5553 necessary to build the native DJGPP version on MS-DOS/MS-Windows
5554 machines ``out of the box''.
5556 The DJGPP version can now debug programs that use signals. It is
5557 possible to catch signals that happened in the debuggee, deliver
5558 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
5559 would kill the program being debugged.) Programs that hook hardware
5560 interrupts (keyboard, timer, etc.) can also be debugged.
5562 It is now possible to debug DJGPP programs that redirect their
5563 standard handles or switch them to raw (as opposed to cooked) mode, or
5564 even close them. The command ``run < foo > bar'' works as expected,
5565 and ``info terminal'' reports useful information about the debuggee's
5566 terminal, including raw/cooked mode, redirection, etc.
5568 The DJGPP version now uses termios functions for console I/O, which
5569 enables debugging graphics programs. Interrupting GDB with Ctrl-C
5572 DOS-style file names with drive letters are now fully supported by
5575 It is now possible to debug DJGPP programs that switch their working
5576 directory. It is also possible to rerun the debuggee any number of
5577 times without restarting GDB; thus, you can use the same setup,
5578 breakpoints, etc. for many debugging sessions.
5580 * New native configurations
5582 ARM GNU/Linux arm*-*-linux*
5583 PowerPC GNU/Linux powerpc-*-linux*
5587 Motorola MCore mcore-*-*
5588 x86 VxWorks i[3456]86-*-vxworks*
5589 PowerPC VxWorks powerpc-*-vxworks*
5590 TI TMS320C80 tic80-*-*
5592 * OBSOLETE configurations
5594 Altos 3068 m68*-altos-*
5595 Convex c1-*-*, c2-*-*
5597 ARM RISCix arm-*-* (as host)
5600 Configurations that have been declared obsolete will be commented out,
5601 but the code will be left in place. If there is no activity to revive
5602 these configurations before the next release of GDB, the sources will
5603 be permanently REMOVED.
5605 * Gould support removed
5607 Support for the Gould PowerNode and NP1 has been removed.
5609 * New features for SVR4
5611 On SVR4 native platforms (such as Solaris), if you attach to a process
5612 without first loading a symbol file, GDB will now attempt to locate and
5613 load symbols from the running process's executable file.
5615 * Many C++ enhancements
5617 C++ support has been greatly improved. Overload resolution now works properly
5618 in almost all cases. RTTI support is on the way.
5620 * Remote targets can connect to a sub-program
5622 A popen(3) style serial-device has been added. This device starts a
5623 sub-process (such as a stand-alone simulator) and then communicates
5624 with that. The sub-program to run is specified using the syntax
5625 ``|<program> <args>'' vis:
5627 (gdb) set remotedebug 1
5628 (gdb) target extended-remote |mn10300-elf-sim program-args
5630 * MIPS 64 remote protocol
5632 A long standing bug in the mips64 remote protocol where by GDB
5633 expected certain 32 bit registers (ex SR) to be transfered as 32
5634 instead of 64 bits has been fixed.
5636 The command ``set remote-mips64-transfers-32bit-regs on'' has been
5637 added to provide backward compatibility with older versions of GDB.
5639 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
5641 The command ``set remotebinarydownload'' command has been replaced by
5642 ``set remote X-packet''. Other commands in ``set remote'' family
5643 include ``set remote P-packet''.
5645 * Breakpoint commands accept ranges.
5647 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
5648 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
5649 ``tracepoint passcount'' also accepts a range of tracepoints.
5651 * ``apropos'' command added.
5653 The ``apropos'' command searches through command names and
5654 documentation strings, printing out matches, making it much easier to
5655 try to find a command that does what you are looking for.
5659 A new machine oriented interface (MI) has been added to GDB. This
5660 interface is designed for debug environments running GDB as a separate
5661 process. This is part of the long term libGDB project. See the
5662 "GDB/MI" chapter of the GDB manual for further information. It can be
5663 enabled by configuring with:
5665 .../configure --enable-gdbmi
5667 *** Changes in GDB-4.18:
5669 * New native configurations
5671 HP-UX 10.20 hppa*-*-hpux10.20
5672 HP-UX 11.x hppa*-*-hpux11.0*
5673 M68K GNU/Linux m68*-*-linux*
5677 Fujitsu FR30 fr30-*-elf*
5678 Intel StrongARM strongarm-*-*
5679 Mitsubishi D30V d30v-*-*
5681 * OBSOLETE configurations
5683 Gould PowerNode, NP1 np1-*-*, pn-*-*
5685 Configurations that have been declared obsolete will be commented out,
5686 but the code will be left in place. If there is no activity to revive
5687 these configurations before the next release of GDB, the sources will
5688 be permanently REMOVED.
5692 As a compatibility experiment, GDB's source files buildsym.h and
5693 buildsym.c have been converted to pure standard C, no longer
5694 containing any K&R compatibility code. We believe that all systems in
5695 use today either come with a standard C compiler, or have a GCC port
5696 available. If this is not true, please report the affected
5697 configuration to bug-gdb@gnu.org immediately. See the README file for
5698 information about getting a standard C compiler if you don't have one
5703 GDB now uses readline 2.2.
5705 * set extension-language
5707 You can now control the mapping between filename extensions and source
5708 languages by using the `set extension-language' command. For instance,
5709 you can ask GDB to treat .c files as C++ by saying
5710 set extension-language .c c++
5711 The command `info extensions' lists all of the recognized extensions
5712 and their associated languages.
5714 * Setting processor type for PowerPC and RS/6000
5716 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
5717 you can use the `set processor' command to specify what variant of the
5718 PowerPC family you are debugging. The command
5722 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
5723 following PowerPC and RS6000 variants:
5725 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
5726 rs6000 IBM RS6000 ("POWER") architecture, user-level view
5728 403GC IBM PowerPC 403GC
5729 505 Motorola PowerPC 505
5730 860 Motorola PowerPC 860 or 850
5731 601 Motorola PowerPC 601
5732 602 Motorola PowerPC 602
5733 603 Motorola/IBM PowerPC 603 or 603e
5734 604 Motorola PowerPC 604 or 604e
5735 750 Motorola/IBM PowerPC 750 or 750
5737 At the moment, this command just tells GDB what to name the
5738 special-purpose processor registers. Since almost all the affected
5739 registers are inaccessible to user-level programs, this command is
5740 only useful for remote debugging in its present form.
5744 Thanks to a major code donation from Hewlett-Packard, GDB now has much
5745 more extensive support for HP-UX. Added features include shared
5746 library support, kernel threads and hardware watchpoints for 11.00,
5747 support for HP's ANSI C and C++ compilers, and a compatibility mode
5748 for xdb and dbx commands.
5752 HP's donation includes the new concept of catchpoints, which is a
5753 generalization of the old catch command. On HP-UX, it is now possible
5754 to catch exec, fork, and vfork, as well as library loading.
5756 This means that the existing catch command has changed; its first
5757 argument now specifies the type of catch to be set up. See the
5758 output of "help catch" for a list of catchpoint types.
5760 * Debugging across forks
5762 On HP-UX, you can choose which process to debug when a fork() happens
5767 HP has donated a curses-based terminal user interface (TUI). To get
5768 it, build with --enable-tui. Although this can be enabled for any
5769 configuration, at present it only works for native HP debugging.
5771 * GDB remote protocol additions
5773 A new protocol packet 'X' that writes binary data is now available.
5774 Default behavior is to try 'X', then drop back to 'M' if the stub
5775 fails to respond. The settable variable `remotebinarydownload'
5776 allows explicit control over the use of 'X'.
5778 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
5779 full 64-bit address. The command
5781 set remoteaddresssize 32
5783 can be used to revert to the old behaviour. For existing remote stubs
5784 the change should not be noticed, as the additional address information
5787 In order to assist in debugging stubs, you may use the maintenance
5788 command `packet' to send any text string to the stub. For instance,
5790 maint packet heythere
5792 sends the packet "$heythere#<checksum>". Note that it is very easy to
5793 disrupt a debugging session by sending the wrong packet at the wrong
5796 The compare-sections command allows you to compare section data on the
5797 target to what is in the executable file without uploading or
5798 downloading, by comparing CRC checksums.
5800 * Tracing can collect general expressions
5802 You may now collect general expressions at tracepoints. This requires
5803 further additions to the target-side stub; see tracepoint.c and
5804 doc/agentexpr.texi for further details.
5806 * mask-address variable for Mips
5808 For Mips targets, you may control the zeroing of the upper 32 bits of
5809 a 64-bit address by entering `set mask-address on'. This is mainly
5810 of interest to users of embedded R4xxx and R5xxx processors.
5812 * Higher serial baud rates
5814 GDB's serial code now allows you to specify baud rates 57600, 115200,
5815 230400, and 460800 baud. (Note that your host system may not be able
5816 to achieve all of these rates.)
5820 The i960 configuration now includes an initial implementation of a
5821 builtin simulator, contributed by Jim Wilson.
5824 *** Changes in GDB-4.17:
5826 * New native configurations
5828 Alpha GNU/Linux alpha*-*-linux*
5829 Unixware 2.x i[3456]86-unixware2*
5830 Irix 6.x mips*-sgi-irix6*
5831 PowerPC GNU/Linux powerpc-*-linux*
5832 PowerPC Solaris powerpcle-*-solaris*
5833 Sparc GNU/Linux sparc-*-linux*
5834 Motorola sysV68 R3V7.1 m68k-motorola-sysv
5838 Argonaut Risc Chip (ARC) arc-*-*
5839 Hitachi H8/300S h8300*-*-*
5840 Matsushita MN10200 w/simulator mn10200-*-*
5841 Matsushita MN10300 w/simulator mn10300-*-*
5842 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
5843 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
5844 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
5845 Mitsubishi D10V w/simulator d10v-*-*
5846 Mitsubishi M32R/D w/simulator m32r-*-elf*
5847 Tsqware Sparclet sparclet-*-*
5848 NEC V850 w/simulator v850-*-*
5850 * New debugging protocols
5852 ARM with RDI protocol arm*-*-*
5853 M68K with dBUG monitor m68*-*-{aout,coff,elf}
5854 DDB and LSI variants of PMON protocol mips*-*-*
5855 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
5856 PowerPC with SDS protocol powerpc{,le}-*-eabi
5857 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
5861 All configurations can now understand and use the DWARF 2 debugging
5862 format. The choice is automatic, if the symbol file contains DWARF 2
5867 GDB now includes basic Java language support. This support is
5868 only useful with Java compilers that produce native machine code.
5870 * solib-absolute-prefix and solib-search-path
5872 For SunOS and SVR4 shared libraries, you may now set the prefix for
5873 loading absolute shared library symbol files, and the search path for
5874 locating non-absolute shared library symbol files.
5876 * Live range splitting
5878 GDB can now effectively debug code for which GCC has performed live
5879 range splitting as part of its optimization. See gdb/doc/LRS for
5880 more details on the expected format of the stabs information.
5884 GDB's support for the GNU Hurd, including thread debugging, has been
5885 updated to work with current versions of the Hurd.
5889 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
5890 instruction set. ARM GDB automatically detects when Thumb
5891 instructions are in use, and adjusts disassembly and backtracing
5896 GDB's MIPS target configurations now handle the MIP16 16-bit
5901 GDB now includes support for overlays; if an executable has been
5902 linked such that multiple sections are based at the same address, GDB
5903 will decide which section to use for symbolic info. You can choose to
5904 control the decision manually, using overlay commands, or implement
5905 additional target-side support and use "overlay load-target" to bring
5906 in the overlay mapping. Do "help overlay" for more detail.
5910 The command "info symbol <address>" displays information about
5911 the symbol at the specified address.
5915 The standard remote protocol now includes an extension that allows
5916 asynchronous collection and display of trace data. This requires
5917 extensive support in the target-side debugging stub. Tracing mode
5918 includes a new interaction mode in GDB and new commands: see the
5919 file tracepoint.c for more details.
5923 Configurations for embedded MIPS now include a simulator contributed
5924 by Cygnus Solutions. The simulator supports the instruction sets
5925 of most MIPS variants.
5929 Sparc configurations may now include the ERC32 simulator contributed
5930 by the European Space Agency. The simulator is not built into
5931 Sparc targets by default; configure with --enable-sim to include it.
5935 For target configurations that may include multiple variants of a
5936 basic architecture (such as MIPS and SH), you may now set the
5937 architecture explicitly. "set arch" sets, "info arch" lists
5938 the possible architectures.
5940 *** Changes in GDB-4.16:
5942 * New native configurations
5944 Windows 95, x86 Windows NT i[345]86-*-cygwin32
5945 M68K NetBSD m68k-*-netbsd*
5946 PowerPC AIX 4.x powerpc-*-aix*
5947 PowerPC MacOS powerpc-*-macos*
5948 PowerPC Windows NT powerpcle-*-cygwin32
5949 RS/6000 AIX 4.x rs6000-*-aix4*
5953 ARM with RDP protocol arm-*-*
5954 I960 with MON960 i960-*-coff
5955 MIPS VxWorks mips*-*-vxworks*
5956 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
5957 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
5959 Matra Sparclet sparclet-*-*
5963 The powerpc-eabi configuration now includes the PSIM simulator,
5964 contributed by Andrew Cagney, with assistance from Mike Meissner.
5965 PSIM is a very elaborate model of the PowerPC, including not only
5966 basic instruction set execution, but also details of execution unit
5967 performance and I/O hardware. See sim/ppc/README for more details.
5971 GDB now works with Solaris 2.5.
5973 * Windows 95/NT native
5975 GDB will now work as a native debugger on Windows 95 and Windows NT.
5976 To build it from source, you must use the "gnu-win32" environment,
5977 which uses a DLL to emulate enough of Unix to run the GNU tools.
5978 Further information, binaries, and sources are available at
5979 ftp.cygnus.com, under pub/gnu-win32.
5981 * dont-repeat command
5983 If a user-defined command includes the command `dont-repeat', then the
5984 command will not be repeated if the user just types return. This is
5985 useful if the command is time-consuming to run, so that accidental
5986 extra keystrokes don't run the same command many times.
5988 * Send break instead of ^C
5990 The standard remote protocol now includes an option to send a break
5991 rather than a ^C to the target in order to interrupt it. By default,
5992 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
5994 * Remote protocol timeout
5996 The standard remote protocol includes a new variable `remotetimeout'
5997 that allows you to set the number of seconds before GDB gives up trying
5998 to read from the target. The default value is 2.
6000 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
6002 By default GDB will automatically keep track of objects as they are
6003 loaded and unloaded by the dynamic linker. By using the command `set
6004 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
6005 when shared library events occur, thus allowing you to set breakpoints
6006 in shared libraries which are explicitly loaded by the inferior.
6008 Note this feature does not work on hpux8. On hpux9 you must link
6009 /usr/lib/end.o into your program. This feature should work
6010 automatically on hpux10.
6012 * Irix 5.x hardware watchpoint support
6014 Irix 5 configurations now support the use of hardware watchpoints.
6016 * Mips protocol "SYN garbage limit"
6018 When debugging a Mips target using the `target mips' protocol, you
6019 may set the number of characters that GDB will ignore by setting
6020 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
6021 every character. The default value is 1050.
6023 * Recording and replaying remote debug sessions
6025 If you set `remotelogfile' to the name of a file, gdb will write to it
6026 a recording of a remote debug session. This recording may then be
6027 replayed back to gdb using "gdbreplay". See gdbserver/README for
6028 details. This is useful when you have a problem with GDB while doing
6029 remote debugging; you can make a recording of the session and send it
6030 to someone else, who can then recreate the problem.
6032 * Speedups for remote debugging
6034 GDB includes speedups for downloading and stepping MIPS systems using
6035 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
6036 and more efficient S-record downloading.
6038 * Memory use reductions and statistics collection
6040 GDB now uses less memory and reports statistics about memory usage.
6041 Try the `maint print statistics' command, for example.
6043 *** Changes in GDB-4.15:
6045 * Psymtabs for XCOFF
6047 The symbol reader for AIX GDB now uses partial symbol tables. This
6048 can greatly improve startup time, especially for large executables.
6050 * Remote targets use caching
6052 Remote targets now use a data cache to speed up communication with the
6053 remote side. The data cache could lead to incorrect results because
6054 it doesn't know about volatile variables, thus making it impossible to
6055 debug targets which use memory mapped I/O devices. `set remotecache
6056 off' turns the the data cache off.
6058 * Remote targets may have threads
6060 The standard remote protocol now includes support for multiple threads
6061 in the target system, using new protocol commands 'H' and 'T'. See
6062 gdb/remote.c for details.
6066 If GDB is configured with `--enable-netrom', then it will include
6067 support for the NetROM ROM emulator from XLNT Designs. The NetROM
6068 acts as though it is a bank of ROM on the target board, but you can
6069 write into it over the network. GDB's support consists only of
6070 support for fast loading into the emulated ROM; to debug, you must use
6071 another protocol, such as standard remote protocol. The usual
6072 sequence is something like
6074 target nrom <netrom-hostname>
6076 target remote <netrom-hostname>:1235
6080 GDB now includes support for the Apple Macintosh, as a host only. It
6081 may be run as either an MPW tool or as a standalone application, and
6082 it can debug through the serial port. All the usual GDB commands are
6083 available, but to the target command, you must supply "serial" as the
6084 device type instead of "/dev/ttyXX". See mpw-README in the main
6085 directory for more information on how to build. The MPW configuration
6086 scripts */mpw-config.in support only a few targets, and only the
6087 mips-idt-ecoff target has been tested.
6091 GDB configuration now uses autoconf. This is not user-visible,
6092 but does simplify configuration and building.
6096 GDB now supports hpux10.
6098 *** Changes in GDB-4.14:
6100 * New native configurations
6102 x86 FreeBSD i[345]86-*-freebsd
6103 x86 NetBSD i[345]86-*-netbsd
6104 NS32k NetBSD ns32k-*-netbsd
6105 Sparc NetBSD sparc-*-netbsd
6109 A29K VxWorks a29k-*-vxworks
6110 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
6111 CPU32 EST-300 emulator m68*-*-est*
6112 PowerPC ELF powerpc-*-elf
6115 * Alpha OSF/1 support for procfs
6117 GDB now supports procfs under OSF/1-2.x and higher, which makes it
6118 possible to attach to running processes. As the mounting of the /proc
6119 filesystem is optional on the Alpha, GDB automatically determines
6120 the availability of /proc during startup. This can lead to problems
6121 if /proc is unmounted after GDB has been started.
6123 * Arguments to user-defined commands
6125 User commands may accept up to 10 arguments separated by whitespace.
6126 Arguments are accessed within the user command via $arg0..$arg9. A
6129 print $arg0 + $arg1 + $arg2
6131 To execute the command use:
6134 Defines the command "adder" which prints the sum of its three arguments.
6135 Note the arguments are text substitutions, so they may reference variables,
6136 use complex expressions, or even perform inferior function calls.
6138 * New `if' and `while' commands
6140 This makes it possible to write more sophisticated user-defined
6141 commands. Both commands take a single argument, which is the
6142 expression to evaluate, and must be followed by the commands to
6143 execute, one per line, if the expression is nonzero, the list being
6144 terminated by the word `end'. The `if' command list may include an
6145 `else' word, which causes the following commands to be executed only
6146 if the expression is zero.
6148 * Fortran source language mode
6150 GDB now includes partial support for Fortran 77. It will recognize
6151 Fortran programs and can evaluate a subset of Fortran expressions, but
6152 variables and functions may not be handled correctly. GDB will work
6153 with G77, but does not yet know much about symbols emitted by other
6156 * Better HPUX support
6158 Most debugging facilities now work on dynamic executables for HPPAs
6159 running hpux9 or later. You can attach to running dynamically linked
6160 processes, but by default the dynamic libraries will be read-only, so
6161 for instance you won't be able to put breakpoints in them. To change
6162 that behavior do the following before running the program:
6168 This will cause the libraries to be mapped private and read-write.
6169 To revert to the normal behavior, do this:
6175 You cannot set breakpoints or examine data in the library until after
6176 the library is loaded if the function/data symbols do not have
6179 GDB can now also read debug symbols produced by the HP C compiler on
6180 HPPAs (sorry, no C++, Fortran or 68k support).
6182 * Target byte order now dynamically selectable
6184 You can choose which byte order to use with a target system, via the
6185 commands "set endian big" and "set endian little", and you can see the
6186 current setting by using "show endian". You can also give the command
6187 "set endian auto", in which case GDB will use the byte order
6188 associated with the executable. Currently, only embedded MIPS
6189 configurations support dynamic selection of target byte order.
6191 * New DOS host serial code
6193 This version uses DPMI interrupts to handle buffered I/O, so you
6194 no longer need to run asynctsr when debugging boards connected to
6197 *** Changes in GDB-4.13:
6199 * New "complete" command
6201 This lists all the possible completions for the rest of the line, if it
6202 were to be given as a command itself. This is intended for use by emacs.
6204 * Trailing space optional in prompt
6206 "set prompt" no longer adds a space for you after the prompt you set. This
6207 allows you to set a prompt which ends in a space or one that does not.
6209 * Breakpoint hit counts
6211 "info break" now displays a count of the number of times the breakpoint
6212 has been hit. This is especially useful in conjunction with "ignore"; you
6213 can ignore a large number of breakpoint hits, look at the breakpoint info
6214 to see how many times the breakpoint was hit, then run again, ignoring one
6215 less than that number, and this will get you quickly to the last hit of
6218 * Ability to stop printing at NULL character
6220 "set print null-stop" will cause GDB to stop printing the characters of
6221 an array when the first NULL is encountered. This is useful when large
6222 arrays actually contain only short strings.
6224 * Shared library breakpoints
6226 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
6227 breakpoints in shared libraries before the executable is run.
6229 * Hardware watchpoints
6231 There is a new hardware breakpoint for the watch command for sparclite
6232 targets. See gdb/sparclite/hw_breakpoint.note.
6234 Hardware watchpoints are also now supported under GNU/Linux.
6238 Annotations have been added. These are for use with graphical interfaces,
6239 and are still experimental. Currently only gdba.el uses these.
6241 * Improved Irix 5 support
6243 GDB now works properly with Irix 5.2.
6245 * Improved HPPA support
6247 GDB now works properly with the latest GCC and GAS.
6249 * New native configurations
6251 Sequent PTX4 i[34]86-sequent-ptx4
6252 HPPA running OSF/1 hppa*-*-osf*
6253 Atari TT running SVR4 m68*-*-sysv4*
6254 RS/6000 LynxOS rs6000-*-lynxos*
6258 OS/9000 i[34]86-*-os9k
6259 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
6262 * Hitachi SH7000 and E7000-PC ICE support
6264 There is now support for communicating with the Hitachi E7000-PC ICE.
6265 This is available automatically when GDB is configured for the SH.
6269 As usual, a variety of small fixes and improvements, both generic
6270 and configuration-specific. See the ChangeLog for more detail.
6272 *** Changes in GDB-4.12:
6274 * Irix 5 is now supported
6278 GDB-4.12 on the HPPA has a number of changes which make it unable
6279 to debug the output from the currently released versions of GCC and
6280 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
6281 of GCC and GAS, versions of these tools designed to work with GDB-4.12
6282 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
6285 *** Changes in GDB-4.11:
6287 * User visible changes:
6291 The "set remotedebug" option is now consistent between the mips remote
6292 target, remote targets using the gdb-specific protocol, UDI (AMD's
6293 debug protocol for the 29k) and the 88k bug monitor. It is now an
6294 integer specifying a debug level (normally 0 or 1, but 2 means more
6295 debugging info for the mips target).
6297 * DEC Alpha native support
6299 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
6300 debug info, but GDB works fairly well with the DEC compiler and should
6301 work with a future GCC release. See the README file for a few
6302 Alpha-specific notes.
6304 * Preliminary thread implementation
6306 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
6308 * LynxOS native and target support for 386
6310 This release has been hosted on LynxOS 2.2, and also can be configured
6311 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
6314 * Improvements in C++ mangling/demangling.
6316 This release has much better g++ debugging, specifically in name
6317 mangling/demangling, virtual function calls, print virtual table,
6318 call methods, ...etc.
6320 *** Changes in GDB-4.10:
6322 * User visible changes:
6324 Remote debugging using the GDB-specific (`target remote') protocol now
6325 supports the `load' command. This is only useful if you have some
6326 other way of getting the stub to the target system, and you can put it
6327 somewhere in memory where it won't get clobbered by the download.
6329 Filename completion now works.
6331 When run under emacs mode, the "info line" command now causes the
6332 arrow to point to the line specified. Also, "info line" prints
6333 addresses in symbolic form (as well as hex).
6335 All vxworks based targets now support a user settable option, called
6336 vxworks-timeout. This option represents the number of seconds gdb
6337 should wait for responses to rpc's. You might want to use this if
6338 your vxworks target is, perhaps, a slow software simulator or happens
6339 to be on the far side of a thin network line.
6343 This release contains support for using a DEC alpha as a GDB host for
6344 cross debugging. Native alpha debugging is not supported yet.
6347 *** Changes in GDB-4.9:
6351 This is the first GDB release which is accompanied by a matching testsuite.
6352 The testsuite requires installation of dejagnu, which should be available
6353 via ftp from most sites that carry GNU software.
6357 'Cfront' style demangling has had its name changed to 'ARM' style, to
6358 emphasize that it was written from the specifications in the C++ Annotated
6359 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
6360 disclaimers, it still generated too much confusion with users attempting to
6361 use gdb with AT&T cfront.
6365 GDB now uses a standard remote interface to a simulator library.
6366 So far, the library contains simulators for the Zilog Z8001/2, the
6367 Hitachi H8/300, H8/500 and Super-H.
6369 * New targets supported
6371 H8/300 simulator h8300-hitachi-hms or h8300hms
6372 H8/500 simulator h8500-hitachi-hms or h8500hms
6373 SH simulator sh-hitachi-hms or sh
6374 Z8000 simulator z8k-zilog-none or z8ksim
6375 IDT MIPS board over serial line mips-idt-ecoff
6377 Cross-debugging to GO32 targets is supported. It requires a custom
6378 version of the i386-stub.c module which is integrated with the
6379 GO32 memory extender.
6381 * New remote protocols
6383 MIPS remote debugging protocol.
6385 * New source languages supported
6387 This version includes preliminary support for Chill, a Pascal like language
6388 used by telecommunications companies. Chill support is also being integrated
6389 into the GNU compiler, but we don't know when it will be publically available.
6392 *** Changes in GDB-4.8:
6394 * HP Precision Architecture supported
6396 GDB now supports HP PA-RISC machines running HPUX. A preliminary
6397 version of this support was available as a set of patches from the
6398 University of Utah. GDB does not support debugging of programs
6399 compiled with the HP compiler, because HP will not document their file
6400 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
6401 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
6403 Many problems in the preliminary version have been fixed.
6405 * Faster and better demangling
6407 We have improved template demangling and fixed numerous bugs in the GNU style
6408 demangler. It can now handle type modifiers such as `static' or `const'. Wide
6409 character types (wchar_t) are now supported. Demangling of each symbol is now
6410 only done once, and is cached when the symbol table for a file is read in.
6411 This results in a small increase in memory usage for C programs, a moderate
6412 increase in memory usage for C++ programs, and a fantastic speedup in
6415 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
6416 from the specifications in the Annotated Reference Manual, which AT&T's
6417 compiler does not actually implement.
6419 * G++ multiple inheritance compiler problem
6421 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
6422 inheritance lattices was reworked to properly discover ambiguities. We
6423 recently found an example which causes this new algorithm to fail in a
6424 very subtle way, producing bad debug information for those classes.
6425 The file 'gcc.patch' (in this directory) can be applied to gcc to
6426 circumvent the problem. A future GCC release will contain a complete
6429 The previous G++ debug info problem (mentioned below for the gdb-4.7
6430 release) is fixed in gcc version 2.3.2.
6432 * Improved configure script
6434 The `configure' script will now attempt to guess your system type if
6435 you don't supply a host system type. The old scheme of supplying a
6436 host system triplet is preferable over using this. All the magic is
6437 done in the new `config.guess' script. Examine it for details.
6439 We have also brought our configure script much more in line with the FSF's
6440 version. It now supports the --with-xxx options. In particular,
6441 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
6442 The resulting GDB will not be able to read arbitrary object file formats --
6443 only the format ``expected'' to be used on the configured target system.
6444 We hope to make this the default in a future release.
6446 * Documentation improvements
6448 There's new internal documentation on how to modify GDB, and how to
6449 produce clean changes to the code. We implore people to read it
6450 before submitting changes.
6452 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
6453 M4 macros. The new texinfo.tex is provided in this release. Pre-built
6454 `info' files are also provided. To build `info' files from scratch,
6455 you will need the latest `makeinfo' release, which will be available in
6456 a future texinfo-X.Y release.
6458 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
6459 We're not sure exactly which versions have this problem, but it has
6460 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
6461 or better. If that isn't possible, there is a patch in
6462 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
6463 around this problem.
6467 GDB now supports array constants that can be used in expressions typed in by
6468 the user. The syntax is `{element, element, ...}'. Ie: you can now type
6469 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
6472 The new directory `gdb/sparclite' contains a program that demonstrates
6473 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
6475 * New native hosts supported
6477 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
6478 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
6480 * New targets supported
6482 AMD 29k family via UDI a29k-amd-udi or udi29k
6484 * New file formats supported
6486 BFD now supports reading HP/PA-RISC executables (SOM file format?),
6487 HPUX core files, and SCO 3.2v2 core files.
6491 Attaching to processes now works again; thanks for the many bug reports.
6493 We have also stomped on a bunch of core dumps caused by
6494 printf_filtered("%s") problems.
6496 We eliminated a copyright problem on the rpc and ptrace header files
6497 for VxWorks, which was discovered at the last minute during the 4.7
6498 release. You should now be able to build a VxWorks GDB.
6500 You can now interrupt gdb while an attached process is running. This
6501 will cause the attached process to stop, and give control back to GDB.
6503 We fixed problems caused by using too many file descriptors
6504 for reading symbols from object files and libraries. This was
6505 especially a problem for programs that used many (~100) shared
6508 The `step' command now only enters a subroutine if there is line number
6509 information for the subroutine. Otherwise it acts like the `next'
6510 command. Previously, `step' would enter subroutines if there was
6511 any debugging information about the routine. This avoids problems
6512 when using `cc -g1' on MIPS machines.
6514 * Internal improvements
6516 GDB's internal interfaces have been improved to make it easier to support
6517 debugging of multiple languages in the future.
6519 GDB now uses a common structure for symbol information internally.
6520 Minimal symbols (derived from linkage symbols in object files), partial
6521 symbols (from a quick scan of debug information), and full symbols
6522 contain a common subset of information, making it easier to write
6523 shared code that handles any of them.
6525 * New command line options
6527 We now accept --silent as an alias for --quiet.
6531 The memory-mapped-malloc library is now licensed under the GNU Library
6532 General Public License.
6534 *** Changes in GDB-4.7:
6536 * Host/native/target split
6538 GDB has had some major internal surgery to untangle the support for
6539 hosts and remote targets. Now, when you configure GDB for a remote
6540 target, it will no longer load in all of the support for debugging
6541 local programs on the host. When fully completed and tested, this will
6542 ensure that arbitrary host/target combinations are possible.
6544 The primary conceptual shift is to separate the non-portable code in
6545 GDB into three categories. Host specific code is required any time GDB
6546 is compiled on that host, regardless of the target. Target specific
6547 code relates to the peculiarities of the target, but can be compiled on
6548 any host. Native specific code is everything else: it can only be
6549 built when the host and target are the same system. Child process
6550 handling and core file support are two common `native' examples.
6552 GDB's use of /proc for controlling Unix child processes is now cleaner.
6553 It has been split out into a single module under the `target_ops' vector,
6554 plus two native-dependent functions for each system that uses /proc.
6556 * New hosts supported
6558 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
6559 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6560 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
6562 * New targets supported
6564 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
6565 68030 and CPU32 m68030-*-*, m68332-*-*
6567 * New native hosts supported
6569 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
6570 (386bsd is not well tested yet)
6571 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
6573 * New file formats supported
6575 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
6576 supports reading of `a.out.adobe' object files, which are an a.out
6577 format extended with minimal information about multiple sections.
6581 `show copying' is the same as the old `info copying'.
6582 `show warranty' is the same as `info warrantee'.
6583 These were renamed for consistency. The old commands continue to work.
6585 `info handle' is a new alias for `info signals'.
6587 You can now define pre-command hooks, which attach arbitrary command
6588 scripts to any command. The commands in the hook will be executed
6589 prior to the user's command. You can also create a hook which will be
6590 executed whenever the program stops. See gdb.texinfo.
6594 We now deal with Cfront style name mangling, and can even extract type
6595 info from mangled symbols. GDB can automatically figure out which
6596 symbol mangling style your C++ compiler uses.
6598 Calling of methods and virtual functions has been improved as well.
6602 The crash that occured when debugging Sun Ansi-C compiled binaries is
6603 fixed. This was due to mishandling of the extra N_SO stabs output
6606 We also finally got Ultrix 4.2 running in house, and fixed core file
6607 support, with help from a dozen people on the net.
6609 John M. Farrell discovered that the reason that single-stepping was so
6610 slow on all of the Mips based platforms (primarily SGI and DEC) was
6611 that we were trying to demangle and lookup a symbol used for internal
6612 purposes on every instruction that was being stepped through. Changing
6613 the name of that symbol so that it couldn't be mistaken for a C++
6614 mangled symbol sped things up a great deal.
6616 Rich Pixley sped up symbol lookups in general by getting much smarter
6617 about when C++ symbol mangling is necessary. This should make symbol
6618 completion (TAB on the command line) much faster. It's not as fast as
6619 we'd like, but it's significantly faster than gdb-4.6.
6623 A new user controllable variable 'call_scratch_address' can
6624 specify the location of a scratch area to be used when GDB
6625 calls a function in the target. This is necessary because the
6626 usual method of putting the scratch area on the stack does not work
6627 in systems that have separate instruction and data spaces.
6629 We integrated changes to support the 29k UDI (Universal Debugger
6630 Interface), but discovered at the last minute that we didn't have all
6631 of the appropriate copyright paperwork. We are working with AMD to
6632 resolve this, and hope to have it available soon.
6636 We have sped up the remote serial line protocol, especially for targets
6637 with lots of registers. It now supports a new `expedited status' ('T')
6638 message which can be used in place of the existing 'S' status message.
6639 This allows the remote stub to send only the registers that GDB
6640 needs to make a quick decision about single-stepping or conditional
6641 breakpoints, eliminating the need to fetch the entire register set for
6642 each instruction being stepped through.
6644 The GDB remote serial protocol now implements a write-through cache for
6645 registers, only re-reading the registers if the target has run.
6647 There is also a new remote serial stub for SPARC processors. You can
6648 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
6649 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
6650 processor with a serial port.
6654 Configure.in files have become much easier to read and modify. A new
6655 `table driven' format makes it more obvious what configurations are
6656 supported, and what files each one uses.
6660 There is a new opcodes library which will eventually contain all of the
6661 disassembly routines and opcode tables. At present, it only contains
6662 Sparc and Z8000 routines. This will allow the assembler, debugger, and
6663 disassembler (binutils/objdump) to share these routines.
6665 The libiberty library is now copylefted under the GNU Library General
6666 Public License. This allows more liberal use, and was done so libg++
6667 can use it. This makes no difference to GDB, since the Library License
6668 grants all the rights from the General Public License.
6672 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
6673 reference to the stabs symbol info used by the debugger. It is (as far
6674 as we know) the only published document on this fascinating topic. We
6675 encourage you to read it, compare it to the stabs information on your
6676 system, and send improvements on the document in general (to
6677 bug-gdb@prep.ai.mit.edu).
6679 And, of course, many bugs have been fixed.
6682 *** Changes in GDB-4.6:
6684 * Better support for C++ function names
6686 GDB now accepts as input the "demangled form" of C++ overloaded function
6687 names and member function names, and can do command completion on such names
6688 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
6689 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
6690 Make use of command completion, it is your friend.
6692 GDB also now accepts a variety of C++ mangled symbol formats. They are
6693 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
6694 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
6695 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
6696 for the list of formats.
6698 * G++ symbol mangling problem
6700 Recent versions of gcc have a bug in how they emit debugging information for
6701 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
6702 directory) can be applied to gcc to fix the problem. Alternatively, if you
6703 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
6704 usual symptom is difficulty with setting breakpoints on methods. GDB complains
6705 about the method being non-existent. (We believe that version 2.2.2 of GCC has
6708 * New 'maintenance' command
6710 All of the commands related to hacking GDB internals have been moved out of
6711 the main command set, and now live behind the 'maintenance' command. This
6712 can also be abbreviated as 'mt'. The following changes were made:
6714 dump-me -> maintenance dump-me
6715 info all-breakpoints -> maintenance info breakpoints
6716 printmsyms -> maintenance print msyms
6717 printobjfiles -> maintenance print objfiles
6718 printpsyms -> maintenance print psymbols
6719 printsyms -> maintenance print symbols
6721 The following commands are new:
6723 maintenance demangle Call internal GDB demangler routine to
6724 demangle a C++ link name and prints the result.
6725 maintenance print type Print a type chain for a given symbol
6727 * Change to .gdbinit file processing
6729 We now read the $HOME/.gdbinit file before processing the argv arguments
6730 (e.g. reading symbol files or core files). This allows global parameters to
6731 be set, which will apply during the symbol reading. The ./.gdbinit is still
6732 read after argv processing.
6734 * New hosts supported
6736 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
6738 GNU/Linux support i386-unknown-linux or linux
6740 We are also including code to support the HP/PA running BSD and HPUX. This
6741 is almost guaranteed not to work, as we didn't have time to test or build it
6742 for this release. We are including it so that the more adventurous (or
6743 masochistic) of you can play with it. We also had major problems with the
6744 fact that the compiler that we got from HP doesn't support the -g option.
6747 * New targets supported
6749 Hitachi H8/300 h8300-hitachi-hms or h8300hms
6751 * More smarts about finding #include files
6753 GDB now remembers the compilation directory for all include files, and for
6754 all files from which C is generated (like yacc and lex sources). This
6755 greatly improves GDB's ability to find yacc/lex sources, and include files,
6756 especially if you are debugging your program from a directory different from
6757 the one that contains your sources.
6759 We also fixed a bug which caused difficulty with listing and setting
6760 breakpoints in include files which contain C code. (In the past, you had to
6761 try twice in order to list an include file that you hadn't looked at before.)
6763 * Interesting infernals change
6765 GDB now deals with arbitrary numbers of sections, where the symbols for each
6766 section must be relocated relative to that section's landing place in the
6767 target's address space. This work was needed to support ELF with embedded
6768 stabs used by Solaris-2.0.
6770 * Bug fixes (of course!)
6772 There have been loads of fixes for the following things:
6773 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
6774 i960, stabs, DOS(GO32), procfs, etc...
6776 See the ChangeLog for details.
6778 *** Changes in GDB-4.5:
6780 * New machines supported (host and target)
6782 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
6784 SGI Irix-4.x mips-sgi-irix4 or iris4
6786 * New malloc package
6788 GDB now uses a new memory manager called mmalloc, based on gmalloc.
6789 Mmalloc is capable of handling mutiple heaps of memory. It is also
6790 capable of saving a heap to a file, and then mapping it back in later.
6791 This can be used to greatly speedup the startup of GDB by using a
6792 pre-parsed symbol table which lives in a mmalloc managed heap. For
6793 more details, please read mmalloc/mmalloc.texi.
6797 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
6798 'help info proc' for details.
6800 * MIPS ecoff symbol table format
6802 The code that reads MIPS symbol table format is now supported on all hosts.
6803 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
6806 * File name changes for MS-DOS
6808 Many files in the config directories have been renamed to make it easier to
6809 support GDB on MS-DOSe systems (which have very restrictive file name
6810 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
6811 environment) is close to working but has some remaining problems. Note
6812 that debugging of DOS programs is not supported, due to limitations
6813 in the ``operating system'', but it can be used to host cross-debugging.
6815 * Cross byte order fixes
6817 Many fixes have been made to support cross debugging of Sparc and MIPS
6818 targets from hosts whose byte order differs.
6820 * New -mapped and -readnow options
6822 If memory-mapped files are available on your system through the 'mmap'
6823 system call, you can use the -mapped option on the `file' or
6824 `symbol-file' commands to cause GDB to write the symbols from your
6825 program into a reusable file. If the program you are debugging is
6826 called `/path/fred', the mapped symbol file will be `./fred.syms'.
6827 Future GDB debugging sessions will notice the presence of this file,
6828 and will quickly map in symbol information from it, rather than reading
6829 the symbol table from the executable program. Using the '-mapped'
6830 option in a GDB `file' or `symbol-file' command has the same effect as
6831 starting GDB with the '-mapped' command-line option.
6833 You can cause GDB to read the entire symbol table immediately by using
6834 the '-readnow' option with any of the commands that load symbol table
6835 information (or on the GDB command line). This makes the command
6836 slower, but makes future operations faster.
6838 The -mapped and -readnow options are typically combined in order to
6839 build a `fred.syms' file that contains complete symbol information.
6840 A simple GDB invocation to do nothing but build a `.syms' file for future
6843 gdb -batch -nx -mapped -readnow programname
6845 The `.syms' file is specific to the host machine on which GDB is run.
6846 It holds an exact image of GDB's internal symbol table. It cannot be
6847 shared across multiple host platforms.
6849 * longjmp() handling
6851 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
6852 siglongjmp() without losing control. This feature has not yet been ported to
6853 all systems. It currently works on many 386 platforms, all MIPS-based
6854 platforms (SGI, DECstation, etc), and Sun3/4.
6858 Preliminary work has been put in to support the new Solaris OS from Sun. At
6859 this time, it can control and debug processes, but it is not capable of
6864 As always, many many bug fixes. The major areas were with g++, and mipsread.
6865 People using the MIPS-based platforms should experience fewer mysterious
6866 crashes and trashed symbol tables.
6868 *** Changes in GDB-4.4:
6870 * New machines supported (host and target)
6872 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6874 BSD Reno on Vax vax-dec-bsd
6875 Ultrix on Vax vax-dec-ultrix
6877 * New machines supported (target)
6879 AMD 29000 embedded, using EBMON a29k-none-none
6883 GDB continues to improve its handling of C++. `References' work better.
6884 The demangler has also been improved, and now deals with symbols mangled as
6885 per the Annotated C++ Reference Guide.
6887 GDB also now handles `stabs' symbol information embedded in MIPS
6888 `ecoff' symbol tables. Since the ecoff format was not easily
6889 extensible to handle new languages such as C++, this appeared to be a
6890 good way to put C++ debugging info into MIPS binaries. This option
6891 will be supported in the GNU C compiler, version 2, when it is
6894 * New features for SVR4
6896 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
6897 shared libraries. Debugging dynamically linked programs should present
6898 only minor differences from debugging statically linked programs.
6900 The `info proc' command will print out information about any process
6901 on an SVR4 system (including the one you are debugging). At the moment,
6902 it prints the address mappings of the process.
6904 If you bring up GDB on another SVR4 system, please send mail to
6905 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
6907 * Better dynamic linking support in SunOS
6909 Reading symbols from shared libraries which contain debugging symbols
6910 now works properly. However, there remain issues such as automatic
6911 skipping of `transfer vector' code during function calls, which
6912 make it harder to debug code in a shared library, than to debug the
6913 same code linked statically.
6917 GDB is now using the latest `getopt' routines from the FSF. This
6918 version accepts the -- prefix for options with long names. GDB will
6919 continue to accept the old forms (-option and +option) as well.
6920 Various single letter abbreviations for options have been explicity
6921 added to the option table so that they won't get overshadowed in the
6922 future by other options that begin with the same letter.
6926 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
6927 Many assorted bugs have been handled. Many more remain to be handled.
6928 See the various ChangeLog files (primarily in gdb and bfd) for details.
6931 *** Changes in GDB-4.3:
6933 * New machines supported (host and target)
6935 Amiga 3000 running Amix m68k-cbm-svr4 or amix
6936 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
6937 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
6939 * Almost SCO Unix support
6941 We had hoped to support:
6942 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
6943 (except for core file support), but we discovered very late in the release
6944 that it has problems with process groups that render gdb unusable. Sorry
6945 about that. I encourage people to fix it and post the fixes.
6947 * Preliminary ELF and DWARF support
6949 GDB can read ELF object files on System V Release 4, and can handle
6950 debugging records for C, in DWARF format, in ELF files. This support
6951 is preliminary. If you bring up GDB on another SVR4 system, please
6952 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
6957 GDB now uses the latest `readline' library. One user-visible change
6958 is that two tabs will list possible command completions, which previously
6959 required typing M-? (meta-question mark, or ESC ?).
6963 The `stepi' bug that many of you noticed has been squashed.
6964 Many bugs in C++ have been handled. Many more remain to be handled.
6965 See the various ChangeLog files (primarily in gdb and bfd) for details.
6967 * State of the MIPS world (in case you wondered):
6969 GDB can understand the symbol tables emitted by the compilers
6970 supplied by most vendors of MIPS-based machines, including DEC. These
6971 symbol tables are in a format that essentially nobody else uses.
6973 Some versions of gcc come with an assembler post-processor called
6974 mips-tfile. This program is required if you want to do source-level
6975 debugging of gcc-compiled programs. I believe FSF does not ship
6976 mips-tfile with gcc version 1, but it will eventually come with gcc
6979 Debugging of g++ output remains a problem. g++ version 1.xx does not
6980 really support it at all. (If you're lucky, you should be able to get
6981 line numbers and stack traces to work, but no parameters or local
6982 variables.) With some work it should be possible to improve the
6985 When gcc version 2 is released, you will have somewhat better luck.
6986 However, even then you will get confusing results for inheritance and
6989 We will eventually provide full debugging of g++ output on
6990 DECstations. This will probably involve some kind of stabs-in-ecoff
6991 encapulation, but the details have not been worked out yet.
6994 *** Changes in GDB-4.2:
6996 * Improved configuration
6998 Only one copy of `configure' exists now, and it is not self-modifying.
6999 Porting BFD is simpler.
7003 The `step' and `next' commands now only stop at the first instruction
7004 of a source line. This prevents the multiple stops that used to occur
7005 in switch statements, for-loops, etc. `Step' continues to stop if a
7006 function that has debugging information is called within the line.
7010 Lots of small bugs fixed. More remain.
7012 * New host supported (not target)
7014 Intel 386 PC clone running Mach i386-none-mach
7017 *** Changes in GDB-4.1:
7019 * Multiple source language support
7021 GDB now has internal scaffolding to handle several source languages.
7022 It determines the type of each source file from its filename extension,
7023 and will switch expression parsing and number formatting to match the
7024 language of the function in the currently selected stack frame.
7025 You can also specifically set the language to be used, with
7026 `set language c' or `set language modula-2'.
7030 GDB now has preliminary support for the GNU Modula-2 compiler,
7031 currently under development at the State University of New York at
7032 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
7033 continue through the fall of 1991 and into 1992.
7035 Other Modula-2 compilers are currently not supported, and attempting to
7036 debug programs compiled with them will likely result in an error as the
7037 symbol table is read. Feel free to work on it, though!
7039 There are hooks in GDB for strict type checking and range checking,
7040 in the `Modula-2 philosophy', but they do not currently work.
7044 GDB can now write to executable and core files (e.g. patch
7045 a variable's value). You must turn this switch on, specify
7046 the file ("exec foo" or "core foo"), *then* modify it, e.g.
7047 by assigning a new value to a variable. Modifications take
7050 * Automatic SunOS shared library reading
7052 When you run your program, GDB automatically determines where its
7053 shared libraries (if any) have been loaded, and reads their symbols.
7054 The `share' command is no longer needed. This also works when
7055 examining core files.
7059 You can specify the number of lines that the `list' command shows.
7062 * New machines supported (host and target)
7064 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
7065 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
7066 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
7068 * New hosts supported (not targets)
7070 IBM RT/PC: romp-ibm-aix or rtpc
7072 * New targets supported (not hosts)
7074 AMD 29000 embedded with COFF a29k-none-coff
7075 AMD 29000 embedded with a.out a29k-none-aout
7076 Ultracomputer remote kernel debug a29k-nyu-kern
7078 * New remote interfaces
7084 *** Changes in GDB-4.0:
7088 Wide output is wrapped at good places to make the output more readable.
7090 Gdb now supports cross-debugging from a host machine of one type to a
7091 target machine of another type. Communication with the target system
7092 is over serial lines. The ``target'' command handles connecting to the
7093 remote system; the ``load'' command will download a program into the
7094 remote system. Serial stubs for the m68k and i386 are provided. Gdb
7095 also supports debugging of realtime processes running under VxWorks,
7096 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
7097 stub on the target system.
7099 New CPUs supported include the AMD 29000 and Intel 960.
7101 GDB now reads object files and symbol tables via a ``binary file''
7102 library, which allows a single copy of GDB to debug programs of multiple
7103 object file types such as a.out and coff.
7105 There is now a GDB reference card in "doc/refcard.tex". (Make targets
7106 refcard.dvi and refcard.ps are available to format it).
7109 * Control-Variable user interface simplified
7111 All variables that control the operation of the debugger can be set
7112 by the ``set'' command, and displayed by the ``show'' command.
7114 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
7115 ``Show prompt'' produces the response:
7116 Gdb's prompt is new-gdb=>.
7118 What follows are the NEW set commands. The command ``help set'' will
7119 print a complete list of old and new set commands. ``help set FOO''
7120 will give a longer description of the variable FOO. ``show'' will show
7121 all of the variable descriptions and their current settings.
7123 confirm on/off: Enables warning questions for operations that are
7124 hard to recover from, e.g. rerunning the program while
7125 it is already running. Default is ON.
7127 editing on/off: Enables EMACS style command line editing
7128 of input. Previous lines can be recalled with
7129 control-P, the current line can be edited with control-B,
7130 you can search for commands with control-R, etc.
7133 history filename NAME: NAME is where the gdb command history
7134 will be stored. The default is .gdb_history,
7135 or the value of the environment variable
7138 history size N: The size, in commands, of the command history. The
7139 default is 256, or the value of the environment variable
7142 history save on/off: If this value is set to ON, the history file will
7143 be saved after exiting gdb. If set to OFF, the
7144 file will not be saved. The default is OFF.
7146 history expansion on/off: If this value is set to ON, then csh-like
7147 history expansion will be performed on
7148 command line input. The default is OFF.
7150 radix N: Sets the default radix for input and output. It can be set
7151 to 8, 10, or 16. Note that the argument to "radix" is interpreted
7152 in the current radix, so "set radix 10" is always a no-op.
7154 height N: This integer value is the number of lines on a page. Default
7155 is 24, the current `stty rows'' setting, or the ``li#''
7156 setting from the termcap entry matching the environment
7159 width N: This integer value is the number of characters on a line.
7160 Default is 80, the current `stty cols'' setting, or the ``co#''
7161 setting from the termcap entry matching the environment
7164 Note: ``set screensize'' is obsolete. Use ``set height'' and
7165 ``set width'' instead.
7167 print address on/off: Print memory addresses in various command displays,
7168 such as stack traces and structure values. Gdb looks
7169 more ``symbolic'' if you turn this off; it looks more
7170 ``machine level'' with it on. Default is ON.
7172 print array on/off: Prettyprint arrays. New convenient format! Default
7175 print demangle on/off: Print C++ symbols in "source" form if on,
7178 print asm-demangle on/off: Same, for assembler level printouts
7181 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
7184 * Support for Epoch Environment.
7186 The epoch environment is a version of Emacs v18 with windowing. One
7187 new command, ``inspect'', is identical to ``print'', except that if you
7188 are running in the epoch environment, the value is printed in its own
7192 * Support for Shared Libraries
7194 GDB can now debug programs and core files that use SunOS shared libraries.
7195 Symbols from a shared library cannot be referenced
7196 before the shared library has been linked with the program (this
7197 happens after you type ``run'' and before the function main() is entered).
7198 At any time after this linking (including when examining core files
7199 from dynamically linked programs), gdb reads the symbols from each
7200 shared library when you type the ``sharedlibrary'' command.
7201 It can be abbreviated ``share''.
7203 sharedlibrary REGEXP: Load shared object library symbols for files
7204 matching a unix regular expression. No argument
7205 indicates to load symbols for all shared libraries.
7207 info sharedlibrary: Status of loaded shared libraries.
7212 A watchpoint stops execution of a program whenever the value of an
7213 expression changes. Checking for this slows down execution
7214 tremendously whenever you are in the scope of the expression, but is
7215 quite useful for catching tough ``bit-spreader'' or pointer misuse
7216 problems. Some machines such as the 386 have hardware for doing this
7217 more quickly, and future versions of gdb will use this hardware.
7219 watch EXP: Set a watchpoint (breakpoint) for an expression.
7221 info watchpoints: Information about your watchpoints.
7223 delete N: Deletes watchpoint number N (same as breakpoints).
7224 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
7225 enable N: Re-enables watchpoint number N (same as breakpoints).
7228 * C++ multiple inheritance
7230 When used with a GCC version 2 compiler, GDB supports multiple inheritance
7233 * C++ exception handling
7235 Gdb now supports limited C++ exception handling. Besides the existing
7236 ability to breakpoint on an exception handler, gdb can breakpoint on
7237 the raising of an exception (before the stack is peeled back to the
7240 catch FOO: If there is a FOO exception handler in the dynamic scope,
7241 set a breakpoint to catch exceptions which may be raised there.
7242 Multiple exceptions (``catch foo bar baz'') may be caught.
7244 info catch: Lists all exceptions which may be caught in the
7245 current stack frame.
7248 * Minor command changes
7250 The command ``call func (arg, arg, ...)'' now acts like the print
7251 command, except it does not print or save a value if the function's result
7252 is void. This is similar to dbx usage.
7254 The ``up'' and ``down'' commands now always print the frame they end up
7255 at; ``up-silently'' and `down-silently'' can be used in scripts to change
7256 frames without printing.
7258 * New directory command
7260 'dir' now adds directories to the FRONT of the source search path.
7261 The path starts off empty. Source files that contain debug information
7262 about the directory in which they were compiled can be found even
7263 with an empty path; Sun CC and GCC include this information. If GDB can't
7264 find your source file in the current directory, type "dir .".
7266 * Configuring GDB for compilation
7268 For normal use, type ``./configure host''. See README or gdb.texinfo
7271 GDB now handles cross debugging. If you are remotely debugging between
7272 two different machines, type ``./configure host -target=targ''.
7273 Host is the machine where GDB will run; targ is the machine
7274 where the program that you are debugging will run.