1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.6
6 * The "maintenance print objfiles" command now takes an optional regexp.
8 * The "catch syscall" command now works on arm*-linux* targets.
12 ** Frame filters and frame decorators have been added.
16 Nios II ELF nios2*-*-elf
17 Nios II GNU/Linux nios2*-*-linux
18 Texas Instruments MSP430 msp430*-*-elf
22 Like "catch throw", but catches a re-thrown exception.
24 Renamed from old "maint check-symtabs".
26 Perform consistency checks on symtabs.
28 Expand symtabs matching an optional regexp.
31 Display the details of GDB configure-time options.
33 maint set|show per-command
34 maint set|show per-command space
35 maint set|show per-command time
36 maint set|show per-command symtab
37 Enable display of per-command gdb resource usage.
41 set print raw frame-arguments
42 show print raw frame-arguments
43 Set/show whether to print frame arguments in raw mode,
44 disregarding any defined pretty-printers.
46 set remote trace-status-packet
47 show remote trace-status-packet
48 Set/show the use of remote protocol qTStatus packet.
52 Control display of debugging messages related to Nios II targets.
56 Control whether target-assisted range stepping is enabled.
58 * You can now use a literal value 'unlimited' for options that
59 interpret 0 or -1 as meaning "unlimited". E.g., "set
60 trace-buffer-size unlimited" is now an alias for "set
61 trace-buffer-size -1" and "set height unlimited" is now an alias for
64 * New command-line options
66 Display the details of GDB configure-time options.
68 * The command 'tsave' can now support new option '-ctf' to save trace
69 buffer in Common Trace Format.
71 * Newly installed $prefix/bin/gcore acts as a shell interface for the
74 * GDB now implements the the C++ 'typeid' operator.
76 * The new convenience variable $_exception holds the exception being
77 thrown or caught at an exception-related catchpoint.
79 * The exception-related catchpoints, like "catch throw", now accept a
80 regular expression which can be used to filter exceptions by type.
84 ** The -trace-save MI command can optionally save trace buffer in Common
87 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
89 ** The command -data-list-register-values now accepts an optional
90 "--skip-unavailable" option. When used, only the available registers
93 ** The new command -trace-frame-collected dumps collected variables,
94 computed expressions, tvars, memory and registers in a traceframe.
96 ** The commands -stack-list-locals, -stack-list-arguments and
97 -stack-list-variables now accept an option "--skip-unavailable".
98 When used, only the available locals or arguments are displayed.
100 * New system-wide configuration scripts
101 A GDB installation now provides scripts suitable for use as system-wide
102 configuration scripts for the following systems:
106 * GDB now supports target-assigned range stepping with remote targets.
107 This improves the performance of stepping source lines by reducing
108 the number of control packets from/to GDB. See "New remote packets"
111 * GDB now understands the element 'tvar' in the XML traceframe info.
112 It has the id of the collected trace state variables.
118 The vCont packet supports a new 'r' action, that tells the remote
119 stub to step through an address range itself, without GDB
120 involvemement at each single-step.
122 qXfer:libraries-svr4:read's annex
123 The previously unused annex of the qXfer:libraries-svr4:read packet
124 is now used to support passing an argument list. The remote stub
125 reports support for this argument list to GDB's qSupported query.
126 The defined arguments are "start" and "prev", used to reduce work
127 necessary for library list updating, resulting in significant
130 * New features in the GDB remote stub, GDBserver
132 ** GDBserver now supports target-assisted range stepping. Currently
133 enabled on x86/x86_64 GNU/Linux targets.
135 ** GDBserver now adds element 'tvar' in the XML in the reply to
136 'qXfer:traceframe-info:read'. It has the id of the collected
137 trace state variables.
139 ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux
142 * New 'z' formatter for printing and examining memory, this displays the
143 value as hexadecimal zero padded on the left to the size of the type.
145 * GDB can now use Windows x64 unwinding data.
147 *** Changes in GDB 7.6
149 * Target record has been renamed to record-full.
150 Record/replay is now enabled with the "record full" command.
151 This also affects settings that are associated with full record/replay
152 that have been moved from "set/show record" to "set/show record full":
154 set|show record full insn-number-max
155 set|show record full stop-at-limit
156 set|show record full memory-query
158 * A new record target "record-btrace" has been added. The new target
159 uses hardware support to record the control-flow of a process. It
160 does not support replaying the execution, but it implements the
161 below new commands for investigating the recorded execution log.
162 This new recording method can be enabled using:
166 The "record-btrace" target is only available on Intel Atom processors
167 and requires a Linux kernel 2.6.32 or later.
169 * Two new commands have been added for record/replay to give information
170 about the recorded execution without having to replay the execution.
171 The commands are only supported by "record btrace".
173 record instruction-history prints the execution history at
174 instruction granularity
176 record function-call-history prints the execution history at
179 * New native configurations
181 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
182 FreeBSD/powerpc powerpc*-*-freebsd
183 x86_64/Cygwin x86_64-*-cygwin*
184 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
188 ARM AArch64 aarch64*-*-elf
189 ARM AArch64 GNU/Linux aarch64*-*-linux
190 Lynx 178 PowerPC powerpc-*-lynx*178
191 x86_64/Cygwin x86_64-*-cygwin*
192 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
194 * If the configured location of system.gdbinit file (as given by the
195 --with-system-gdbinit option at configure time) is in the
196 data-directory (as specified by --with-gdb-datadir at configure
197 time) or in one of its subdirectories, then GDB will look for the
198 system-wide init file in the directory specified by the
199 --data-directory command-line option.
201 * New command line options:
203 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
204 other initialization files, unlike -nx which disables all of them.
206 * Removed command line options
208 -epoch This was used by the gdb mode in Epoch, an ancient fork of
211 * The 'ptype' and 'whatis' commands now accept an argument to control
214 * 'info proc' now works on some core files.
218 ** Vectors can be created with gdb.Type.vector.
220 ** Python's atexit.register now works in GDB.
222 ** Types can be pretty-printed via a Python API.
224 ** Python 3 is now supported (in addition to Python 2.4 or later)
226 ** New class gdb.Architecture exposes GDB's internal representation
227 of architecture in the Python API.
229 ** New method Frame.architecture returns the gdb.Architecture object
230 corresponding to the frame's architecture.
232 * New Python-based convenience functions:
234 ** $_memeq(buf1, buf2, length)
235 ** $_streq(str1, str2)
237 ** $_regex(str, regex)
239 * The 'cd' command now defaults to using '~' (the home directory) if not
242 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
243 default for GCC since November 2000.
245 * The command 'forward-search' can now be abbreviated as 'fo'.
247 * The command 'info tracepoints' can now display 'installed on target'
248 or 'not installed on target' for each non-pending location of tracepoint.
250 * New configure options
252 --enable-libmcheck/--disable-libmcheck
253 By default, development versions are built with -lmcheck on hosts
254 that support it, in order to help track memory corruption issues.
255 Release versions, on the other hand, are built without -lmcheck
256 by default. The --enable-libmcheck/--disable-libmcheck configure
257 options allow the user to override that default.
258 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
259 This configure option allows the user to build GDB with
260 libbabeltrace using which GDB can read Common Trace Format data.
262 * New commands (for set/show, see "New options" below)
265 Catch signals. This is similar to "handle", but allows commands and
266 conditions to be attached.
269 List the BFDs known to GDB.
271 python-interactive [command]
273 Start a Python interactive prompt, or evaluate the optional command
274 and print the result of expressions.
277 "py" is a new alias for "python".
279 enable type-printer [name]...
280 disable type-printer [name]...
281 Enable or disable type printers.
285 ** For the Renesas Super-H architecture, the "regs" command has been removed
286 (has been deprecated in GDB 7.5), and "info all-registers" should be used
291 set print type methods (on|off)
292 show print type methods
293 Control whether method declarations are displayed by "ptype".
294 The default is to show them.
296 set print type typedefs (on|off)
297 show print type typedefs
298 Control whether typedef definitions are displayed by "ptype".
299 The default is to show them.
301 set filename-display basename|relative|absolute
302 show filename-display
303 Control the way in which filenames is displayed.
304 The default is "relative", which preserves previous behavior.
306 set trace-buffer-size
307 show trace-buffer-size
308 Request target to change the size of trace buffer.
310 set remote trace-buffer-size-packet auto|on|off
311 show remote trace-buffer-size-packet
312 Control the use of the remote protocol `QTBuffer:size' packet.
316 Control display of debugging messages related to ARM AArch64.
319 set debug coff-pe-read
320 show debug coff-pe-read
321 Control display of debugging messages related to reading of COFF/PE
326 Control display of debugging messages related to Mach-O symbols
329 set debug notification
330 show debug notification
331 Control display of debugging info for async remote notification.
335 ** Command parameter changes are now notified using new async record
336 "=cmd-param-changed".
337 ** Trace frame changes caused by command "tfind" are now notified using
338 new async record "=traceframe-changed".
339 ** The creation, deletion and modification of trace state variables
340 are now notified using new async records "=tsv-created",
341 "=tsv-deleted" and "=tsv-modified".
342 ** The start and stop of process record are now notified using new
343 async record "=record-started" and "=record-stopped".
344 ** Memory changes are now notified using new async record
346 ** The data-disassemble command response will include a "fullname" field
347 containing the absolute file name when source has been requested.
348 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
349 command, to allow pattern filling of memory areas.
350 ** New commands "-catch-load"/"-catch-unload" added for intercepting
351 library load/unload events.
352 ** The response to breakpoint commands and breakpoint async records
353 includes an "installed" field containing a boolean state about each
354 non-pending tracepoint location is whether installed on target or not.
355 ** Output of the "-trace-status" command includes a "trace-file" field
356 containing the name of the trace file being examined. This field is
357 optional, and only present when examining a trace file.
358 ** The "fullname" field is now always present along with the "file" field,
359 even if the file cannot be found by GDB.
361 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
362 You must have the LZMA library available when configuring GDB for this
363 feature to be enabled. For more information, see:
364 http://fedoraproject.org/wiki/Features/MiniDebugInfo
369 Set the size of trace buffer. The remote stub reports support for this
370 packet to gdb's qSupported query.
373 Enable Branch Trace Store (BTS)-based branch tracing for the current
374 thread. The remote stub reports support for this packet to gdb's
378 Disable branch tracing for the current thread. The remote stub reports
379 support for this packet to gdb's qSupported query.
382 Read the traced branches for the current thread. The remote stub
383 reports support for this packet to gdb's qSupported query.
385 *** Changes in GDB 7.5
387 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
388 for more x32 ABI info.
390 * GDB now supports access to MIPS DSP registers on Linux targets.
392 * GDB now supports debugging microMIPS binaries.
394 * The "info os" command on GNU/Linux can now display information on
395 several new classes of objects managed by the operating system:
396 "info os procgroups" lists process groups
397 "info os files" lists file descriptors
398 "info os sockets" lists internet-domain sockets
399 "info os shm" lists shared-memory regions
400 "info os semaphores" lists semaphores
401 "info os msg" lists message queues
402 "info os modules" lists loaded kernel modules
404 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
405 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
406 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
407 options and inspect the probe arguments using the new $_probe_arg family
408 of convenience variables. You can obtain more information about SystemTap
409 in <http://sourceware.org/systemtap/>.
411 * GDB now supports reversible debugging on ARM, it allows you to
412 debug basic ARM and THUMB instructions, and provides
413 record/replay support.
415 * The option "symbol-reloading" has been deleted as it is no longer used.
419 ** GDB commands implemented in Python can now be put in command class
422 ** The "maint set python print-stack on|off" is now deleted.
424 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
425 apply "flag enum"-style pretty-printing to any enum.
427 ** gdb.lookup_symbol can now work when there is no current frame.
429 ** gdb.Symbol now has a 'line' attribute, holding the line number in
430 the source at which the symbol was defined.
432 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
433 method 'value'. The former indicates whether the symbol needs a
434 frame in order to compute its value, and the latter computes the
437 ** A new method 'referenced_value' on gdb.Value objects which can
438 dereference pointer as well as C++ reference values.
440 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
441 which return the global and static blocks (as gdb.Block objects),
442 of the underlying symbol table, respectively.
444 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
445 object associated with a PC value.
447 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
448 of the address range occupied by code for the current source line.
450 * Go language support.
451 GDB now supports debugging programs written in the Go programming
454 * GDBserver now supports stdio connections.
455 E.g. (gdb) target remote | ssh myhost gdbserver - hello
457 * The binary "gdbtui" can no longer be built or installed.
458 Use "gdb -tui" instead.
460 * GDB will now print "flag" enums specially. A flag enum is one where
461 all the enumerator values have no bits in common when pairwise
462 "and"ed. When printing a value whose type is a flag enum, GDB will
463 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
464 (gdb) print (enum E) 3
467 * The filename part of a linespec will now match trailing components
468 of a source file name. For example, "break gcc/expr.c:1000" will
469 now set a breakpoint in build/gcc/expr.c, but not
472 * The "info proc" and "generate-core-file" commands will now also
473 work on remote targets connected to GDBserver on Linux.
475 * The command "info catch" has been removed. It has been disabled
478 * The "catch exception" and "catch assert" commands now accept
479 a condition at the end of the command, much like the "break"
480 command does. For instance:
482 (gdb) catch exception Constraint_Error if Barrier = True
484 Previously, it was possible to add a condition to such catchpoints,
485 but it had to be done as a second step, after the catchpoint had been
486 created, using the "condition" command.
488 * The "info static-tracepoint-marker" command will now also work on
489 native Linux targets with in-process agent.
491 * GDB can now set breakpoints on inlined functions.
493 * The .gdb_index section has been updated to include symbols for
494 inlined functions. GDB will ignore older .gdb_index sections by
495 default, which could cause symbol files to be loaded more slowly
496 until their .gdb_index sections can be recreated. The new command
497 "set use-deprecated-index-sections on" will cause GDB to use any older
498 .gdb_index sections it finds. This will restore performance, but the
499 ability to set breakpoints on inlined functions will be lost in symbol
500 files with older .gdb_index sections.
502 The .gdb_index section has also been updated to record more information
503 about each symbol. This speeds up the "info variables", "info functions"
504 and "info types" commands when used with programs having the .gdb_index
505 section, as well as speeding up debugging with shared libraries using
506 the .gdb_index section.
508 * Ada support for GDB/MI Variable Objects has been added.
510 * GDB can now support 'breakpoint always-inserted mode' in 'record'
515 ** New command -info-os is the MI equivalent of "info os".
517 ** Output logs ("set logging" and related) now include MI output.
521 ** "set use-deprecated-index-sections on|off"
522 "show use-deprecated-index-sections on|off"
523 Controls the use of deprecated .gdb_index sections.
525 ** "catch load" and "catch unload" can be used to stop when a shared
526 library is loaded or unloaded, respectively.
528 ** "enable count" can be used to auto-disable a breakpoint after
531 ** "info vtbl" can be used to show the virtual method tables for
532 C++ and Java objects.
534 ** "explore" and its sub commands "explore value" and "explore type"
535 can be used to reccursively explore values and types of
536 expressions. These commands are available only if GDB is
537 configured with '--with-python'.
539 ** "info auto-load" shows status of all kinds of auto-loaded files,
540 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
541 sequences of commands files, "info auto-load python-scripts"
542 shows status of auto-loading Python script files,
543 "info auto-load local-gdbinit" shows status of loading init file
544 (.gdbinit) from current directory and "info auto-load libthread-db" shows
545 status of inferior specific thread debugging shared library loading.
547 ** "info auto-load-scripts", "set auto-load-scripts on|off"
548 and "show auto-load-scripts" commands have been deprecated, use their
549 "info auto-load python-scripts", "set auto-load python-scripts on|off"
550 and "show auto-load python-scripts" counterparts instead.
552 ** "dprintf location,format,args..." creates a dynamic printf, which
553 is basically a breakpoint that does a printf and immediately
554 resumes your program's execution, so it is like a printf that you
555 can insert dynamically at runtime instead of at compiletime.
557 ** "set print symbol"
559 Controls whether GDB attempts to display the symbol, if any,
560 corresponding to addresses it prints. This defaults to "on", but
561 you can set it to "off" to restore GDB's previous behavior.
563 * Deprecated commands
565 ** For the Renesas Super-H architecture, the "regs" command has been
566 deprecated, and "info all-registers" should be used instead.
570 Renesas RL78 rl78-*-elf
571 HP OpenVMS ia64 ia64-hp-openvms*
573 * GDBserver supports evaluation of breakpoint conditions. When
574 support is advertised by GDBserver, GDB may be told to send the
575 breakpoint conditions in bytecode form to GDBserver. GDBserver
576 will only report the breakpoint trigger to GDB when its condition
582 show mips compression
583 Select the compressed ISA encoding used in functions that have no symbol
584 information available. The encoding can be set to either of:
587 and is updated automatically from ELF file flags if available.
589 set breakpoint condition-evaluation
590 show breakpoint condition-evaluation
591 Control whether breakpoint conditions are evaluated by GDB ("host") or by
592 GDBserver ("target"). Default option "auto" chooses the most efficient
594 This option can improve debugger efficiency depending on the speed of the
598 Disable auto-loading globally.
601 Show auto-loading setting of all kinds of auto-loaded files.
603 set auto-load gdb-scripts on|off
604 show auto-load gdb-scripts
605 Control auto-loading of GDB canned sequences of commands files.
607 set auto-load python-scripts on|off
608 show auto-load python-scripts
609 Control auto-loading of Python script files.
611 set auto-load local-gdbinit on|off
612 show auto-load local-gdbinit
613 Control loading of init file (.gdbinit) from current directory.
615 set auto-load libthread-db on|off
616 show auto-load libthread-db
617 Control auto-loading of inferior specific thread debugging shared library.
619 set auto-load scripts-directory <dir1>[:<dir2>...]
620 show auto-load scripts-directory
621 Set a list of directories from which to load auto-loaded scripts.
622 Automatically loaded Python scripts and GDB scripts are located in one
623 of the directories listed by this option.
624 The delimiter (':' above) may differ according to the host platform.
626 set auto-load safe-path <dir1>[:<dir2>...]
627 show auto-load safe-path
628 Set a list of directories from which it is safe to auto-load files.
629 The delimiter (':' above) may differ according to the host platform.
631 set debug auto-load on|off
633 Control display of debugging info for auto-loading the files above.
635 set dprintf-style gdb|call|agent
637 Control the way in which a dynamic printf is performed; "gdb"
638 requests a GDB printf command, while "call" causes dprintf to call a
639 function in the inferior. "agent" requests that the target agent
640 (such as GDBserver) do the printing.
642 set dprintf-function <expr>
643 show dprintf-function
644 set dprintf-channel <expr>
646 Set the function and optional first argument to the call when using
647 the "call" style of dynamic printf.
649 set disconnected-dprintf on|off
650 show disconnected-dprintf
651 Control whether agent-style dynamic printfs continue to be in effect
652 after GDB disconnects.
654 * New configure options
657 Configure default value for the 'set auto-load scripts-directory'
658 setting above. It defaults to '$debugdir:$datadir/auto-load',
659 $debugdir representing global debugging info directories (available
660 via 'show debug-file-directory') and $datadir representing GDB's data
661 directory (available via 'show data-directory').
663 --with-auto-load-safe-path
664 Configure default value for the 'set auto-load safe-path' setting
665 above. It defaults to the --with-auto-load-dir setting.
667 --without-auto-load-safe-path
668 Set 'set auto-load safe-path' to '/', effectively disabling this
673 z0/z1 conditional breakpoints extension
675 The z0/z1 breakpoint insertion packets have been extended to carry
676 a list of conditional expressions over to the remote stub depending on the
677 condition evaluation mode. The use of this extension can be controlled
678 via the "set remote conditional-breakpoints-packet" command.
682 Specify the signals which the remote stub may pass to the debugged
683 program without GDB involvement.
685 * New command line options
687 --init-command=FILE, -ix Like --command, -x but execute it
688 before loading inferior.
689 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
690 execute it before loading inferior.
692 *** Changes in GDB 7.4
694 * GDB now handles ambiguous linespecs more consistently; the existing
695 FILE:LINE support has been expanded to other types of linespecs. A
696 breakpoint will now be set on all matching locations in all
697 inferiors, and locations will be added or removed according to
700 * GDB now allows you to skip uninteresting functions and files when
701 stepping with the "skip function" and "skip file" commands.
703 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
704 and "show remote hardware-watchpoint-length-limit". These allows to
705 set or show the maximum length limit (in bytes) of a remote
706 target hardware watchpoint.
708 This allows e.g. to use "unlimited" hardware watchpoints with the
709 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
710 watchpoints are slower than real hardware watchpoints but are
711 significantly faster than gdb software watchpoints.
715 ** The register_pretty_printer function in module gdb.printing now takes
716 an optional `replace' argument. If True, the new printer replaces any
719 ** The "maint set python print-stack on|off" command has been
720 deprecated and will be deleted in GDB 7.5.
721 A new command: "set python print-stack none|full|message" has
722 replaced it. Additionally, the default for "print-stack" is
723 now "message", which just prints the error message without
726 ** A prompt substitution hook (prompt_hook) is now available to the
729 ** A new Python module, gdb.prompt has been added to the GDB Python
730 modules library. This module provides functionality for
731 escape sequences in prompts (used by set/show
732 extended-prompt). These escape sequences are replaced by their
735 ** Python commands and convenience-functions located in
736 'data-directory'/python/gdb/command and
737 'data-directory'/python/gdb/function are now automatically loaded
740 ** Blocks now provide four new attributes. global_block and
741 static_block will return the global and static blocks
742 respectively. is_static and is_global are boolean attributes
743 that indicate if the block is one of those two types.
745 ** Symbols now provide the "type" attribute, the type of the symbol.
747 ** The "gdb.breakpoint" function has been deprecated in favor of
750 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
751 of a function. This class is based on the "finish" command
752 available in the CLI.
754 ** Type objects for struct and union types now allow access to
755 the fields using standard Python dictionary (mapping) methods.
756 For example, "some_type['myfield']" now works, as does
759 ** A new event "gdb.new_objfile" has been added, triggered by loading a
762 ** A new function, "deep_items" has been added to the gdb.types
763 module in the GDB Python modules library. This function returns
764 an iterator over the fields of a struct or union type. Unlike
765 the standard Python "iteritems" method, it will recursively traverse
766 any anonymous fields.
770 ** "*stopped" events can report several new "reason"s, such as
773 ** Breakpoint changes are now notified using new async records, like
774 "=breakpoint-modified".
776 ** New command -ada-task-info.
778 * libthread-db-search-path now supports two special values: $sdir and $pdir.
779 $sdir specifies the default system locations of shared libraries.
780 $pdir specifies the directory where the libpthread used by the application
783 GDB no longer looks in $sdir and $pdir after it has searched the directories
784 mentioned in libthread-db-search-path. If you want to search those
785 directories, they must be specified in libthread-db-search-path.
786 The default value of libthread-db-search-path on GNU/Linux and Solaris
787 systems is now "$sdir:$pdir".
789 $pdir is not supported by gdbserver, it is currently ignored.
790 $sdir is supported by gdbserver.
792 * New configure option --with-iconv-bin.
793 When using the internationalization support like the one in the GNU C
794 library, GDB will invoke the "iconv" program to get a list of supported
795 character sets. If this program lives in a non-standard location, one can
796 use this option to specify where to find it.
798 * When natively debugging programs on PowerPC BookE processors running
799 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
800 watchpoints, which specify a mask in addition to an address to watch.
801 The mask specifies that some bits of an address (the bits which are
802 reset in the mask) should be ignored when matching the address accessed
803 by the inferior against the watchpoint address. See the "PowerPC Embedded"
804 section in the user manual for more details.
806 * The new option --once causes GDBserver to stop listening for connections once
807 the first connection is made. The listening port used by GDBserver will
808 become available after that.
810 * New commands "info macros" and "alias" have been added.
812 * New function parameters suffix @entry specifies value of function parameter
813 at the time the function got called. Entry values are available only since
819 "!" is now an alias of the "shell" command.
820 Note that no space is needed between "!" and SHELL COMMAND.
824 watch EXPRESSION mask MASK_VALUE
825 The watch command now supports the mask argument which allows creation
826 of masked watchpoints, if the current architecture supports this feature.
828 info auto-load-scripts [REGEXP]
829 This command was formerly named "maintenance print section-scripts".
830 It is now generally useful and is no longer a maintenance-only command.
832 info macro [-all] [--] MACRO
833 The info macro command has new options `-all' and `--'. The first for
834 printing all definitions of a macro. The second for explicitly specifying
835 the end of arguments and the beginning of the macro name in case the macro
836 name starts with a hyphen.
838 collect[/s] EXPRESSIONS
839 The tracepoint collect command now takes an optional modifier "/s"
840 that directs it to dereference pointer-to-character types and
841 collect the bytes of memory up to a zero byte. The behavior is
842 similar to what you see when you use the regular print command on a
843 string. An optional integer following the "/s" sets a bound on the
844 number of bytes that will be collected.
847 The trace start command now interprets any supplied arguments as a
848 note to be recorded with the trace run, with an effect similar to
849 setting the variable trace-notes.
852 The trace stop command now interprets any arguments as a note to be
853 mentioned along with the tstatus report that the trace was stopped
854 with a command. The effect is similar to setting the variable
857 * Tracepoints can now be enabled and disabled at any time after a trace
858 experiment has been started using the standard "enable" and "disable"
859 commands. It is now possible to start a trace experiment with no enabled
860 tracepoints; GDB will display a warning, but will allow the experiment to
861 begin, assuming that tracepoints will be enabled as needed while the trace
864 * Fast tracepoints on 32-bit x86-architectures can now be placed at
865 locations with 4-byte instructions, when they were previously
866 limited to locations with instructions of 5 bytes or longer.
870 set debug dwarf2-read
871 show debug dwarf2-read
872 Turns on or off display of debugging messages related to reading
873 DWARF debug info. The default is off.
875 set debug symtab-create
876 show debug symtab-create
877 Turns on or off display of debugging messages related to symbol table
878 creation. The default is off.
882 Set the GDB prompt, and allow escape sequences to be inserted to
883 display miscellaneous information (see 'help set extended-prompt'
884 for the list of sequences). This prompt (and any information
885 accessed through the escape sequences) is updated every time the
888 set print entry-values (both|compact|default|if-needed|no|only|preferred)
889 show print entry-values
890 Set printing of frame argument values at function entry. In some cases
891 GDB can determine the value of function argument which was passed by the
892 function caller, even if the value was modified inside the called function.
894 set debug entry-values
895 show debug entry-values
896 Control display of debugging info for determining frame argument values at
897 function entry and virtual tail call frames.
899 set basenames-may-differ
900 show basenames-may-differ
901 Set whether a source file may have multiple base names.
902 (A "base name" is the name of a file with the directory part removed.
903 Example: The base name of "/home/user/hello.c" is "hello.c".)
904 If set, GDB will canonicalize file names (e.g., expand symlinks)
905 before comparing them. Canonicalization is an expensive operation,
906 but it allows the same file be known by more than one base name.
907 If not set (the default), all source files are assumed to have just
908 one base name, and gdb will do file name comparisons more efficiently.
914 Set a user name and notes for the current and any future trace runs.
915 This is useful for long-running and/or disconnected traces, to
916 inform others (or yourself) as to who is running the trace, supply
917 contact information, or otherwise explain what is going on.
920 show trace-stop-notes
921 Set a note attached to the trace run, that is displayed when the
922 trace has been stopped by a tstop command. This is useful for
923 instance as an explanation, if you are stopping a trace run that was
924 started by someone else.
930 Dynamically enable a tracepoint in a started trace experiment.
934 Dynamically disable a tracepoint in a started trace experiment.
938 Set the user and notes of the trace run.
942 Query the current status of a tracepoint.
946 Query the minimum length of instruction at which a fast tracepoint may
949 * Dcache size (number of lines) and line-size are now runtime-configurable
950 via "set dcache line" and "set dcache line-size" commands.
954 Texas Instruments TMS320C6x tic6x-*-*
958 Renesas RL78 rl78-*-elf
960 *** Changes in GDB 7.3.1
962 * The build failure for NetBSD and OpenBSD targets have now been fixed.
964 *** Changes in GDB 7.3
966 * GDB has a new command: "thread find [REGEXP]".
967 It finds the thread id whose name, target id, or thread extra info
968 matches the given regular expression.
970 * The "catch syscall" command now works on mips*-linux* targets.
972 * The -data-disassemble MI command now supports modes 2 and 3 for
973 dumping the instruction opcodes.
975 * New command line options
977 -data-directory DIR Specify DIR as the "data-directory".
978 This is mostly for testing purposes.
980 * The "maint set python auto-load on|off" command has been renamed to
981 "set auto-load-scripts on|off".
983 * GDB has a new command: "set directories".
984 It is like the "dir" command except that it replaces the
985 source path list instead of augmenting it.
987 * GDB now understands thread names.
989 On GNU/Linux, "info threads" will display the thread name as set by
990 prctl or pthread_setname_np.
992 There is also a new command, "thread name", which can be used to
993 assign a name internally for GDB to display.
996 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
997 has been integrated into GDB.
1001 ** The function gdb.Write now accepts an optional keyword 'stream'.
1002 This keyword, when provided, will direct the output to either
1003 stdout, stderr, or GDB's logging output.
1005 ** Parameters can now be be sub-classed in Python, and in particular
1006 you may implement the get_set_doc and get_show_doc functions.
1007 This improves how Parameter set/show documentation is processed
1008 and allows for more dynamic content.
1010 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
1011 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
1012 have an is_valid method.
1014 ** Breakpoints can now be sub-classed in Python, and in particular
1015 you may implement a 'stop' function that is executed each time
1016 the inferior reaches that breakpoint.
1018 ** New function gdb.lookup_global_symbol looks up a global symbol.
1020 ** GDB values in Python are now callable if the value represents a
1021 function. For example, if 'some_value' represents a function that
1022 takes two integer parameters and returns a value, you can call
1023 that function like so:
1025 result = some_value (10,20)
1027 ** Module gdb.types has been added.
1028 It contains a collection of utilities for working with gdb.Types objects:
1029 get_basic_type, has_field, make_enum_dict.
1031 ** Module gdb.printing has been added.
1032 It contains utilities for writing and registering pretty-printers.
1033 New classes: PrettyPrinter, SubPrettyPrinter,
1034 RegexpCollectionPrettyPrinter.
1035 New function: register_pretty_printer.
1037 ** New commands "info pretty-printers", "enable pretty-printer" and
1038 "disable pretty-printer" have been added.
1040 ** gdb.parameter("directories") is now available.
1042 ** New function gdb.newest_frame returns the newest frame in the
1045 ** The gdb.InferiorThread class has a new "name" attribute. This
1046 holds the thread's name.
1048 ** Python Support for Inferior events.
1049 Python scripts can add observers to be notified of events
1050 occurring in the process being debugged.
1051 The following events are currently supported:
1052 - gdb.events.cont Continue event.
1053 - gdb.events.exited Inferior exited event.
1054 - gdb.events.stop Signal received, and Breakpoint hit events.
1058 ** GDB now puts template parameters in scope when debugging in an
1059 instantiation. For example, if you have:
1061 template<int X> int func (void) { return X; }
1063 then if you step into func<5>, "print X" will show "5". This
1064 feature requires proper debuginfo support from the compiler; it
1065 was added to GCC 4.5.
1067 ** The motion commands "next", "finish", "until", and "advance" now
1068 work better when exceptions are thrown. In particular, GDB will
1069 no longer lose control of the inferior; instead, the GDB will
1070 stop the inferior at the point at which the exception is caught.
1071 This functionality requires a change in the exception handling
1072 code that was introduced in GCC 4.5.
1074 * GDB now follows GCC's rules on accessing volatile objects when
1075 reading or writing target state during expression evaluation.
1076 One notable difference to prior behavior is that "print x = 0"
1077 no longer generates a read of x; the value of the assignment is
1078 now always taken directly from the value being assigned.
1080 * GDB now has some support for using labels in the program's source in
1081 linespecs. For instance, you can use "advance label" to continue
1082 execution to a label.
1084 * GDB now has support for reading and writing a new .gdb_index
1085 section. This section holds a fast index of DWARF debugging
1086 information and can be used to greatly speed up GDB startup and
1087 operation. See the documentation for `save gdb-index' for details.
1089 * The "watch" command now accepts an optional "-location" argument.
1090 When used, this causes GDB to watch the memory referred to by the
1091 expression. Such a watchpoint is never deleted due to it going out
1094 * GDB now supports thread debugging of core dumps on GNU/Linux.
1096 GDB now activates thread debugging using the libthread_db library
1097 when debugging GNU/Linux core dumps, similarly to when debugging
1098 live processes. As a result, when debugging a core dump file, GDB
1099 is now able to display pthread_t ids of threads. For example, "info
1100 threads" shows the same output as when debugging the process when it
1101 was live. In earlier releases, you'd see something like this:
1104 * 1 LWP 6780 main () at main.c:10
1106 While now you see this:
1109 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1111 It is also now possible to inspect TLS variables when debugging core
1114 When debugging a core dump generated on a machine other than the one
1115 used to run GDB, you may need to point GDB at the correct
1116 libthread_db library with the "set libthread-db-search-path"
1117 command. See the user manual for more details on this command.
1119 * When natively debugging programs on PowerPC BookE processors running
1120 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1121 which stop execution of the inferior whenever it executes an instruction
1122 at any address within the specified range. See the "PowerPC Embedded"
1123 section in the user manual for more details.
1125 * New features in the GDB remote stub, GDBserver
1127 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1128 and i686 LynxOS (version 5.x).
1130 ** GDBserver is now supported on Blackfin Linux.
1132 * New native configurations
1134 ia64 HP-UX ia64-*-hpux*
1138 Analog Devices, Inc. Blackfin Processor bfin-*
1140 * Ada task switching is now supported on sparc-elf targets when
1141 debugging a program using the Ravenscar Profile. For more information,
1142 see the "Tasking Support when using the Ravenscar Profile" section
1143 in the GDB user manual.
1145 * Guile support was removed.
1147 * New features in the GNU simulator
1149 ** The --map-info flag lists all known core mappings.
1151 ** CFI flashes may be simulated via the "cfi" device.
1153 *** Changes in GDB 7.2
1155 * Shared library support for remote targets by default
1157 When GDB is configured for a generic, non-OS specific target, like
1158 for example, --target=arm-eabi or one of the many *-*-elf targets,
1159 GDB now queries remote stubs for loaded shared libraries using the
1160 `qXfer:libraries:read' packet. Previously, shared library support
1161 was always disabled for such configurations.
1165 ** Argument Dependent Lookup (ADL)
1167 In C++ ADL lookup directs function search to the namespaces of its
1168 arguments even if the namespace has not been imported.
1178 Here the compiler will search for `foo' in the namespace of 'b'
1179 and find A::foo. GDB now supports this. This construct is commonly
1180 used in the Standard Template Library for operators.
1182 ** Improved User Defined Operator Support
1184 In addition to member operators, GDB now supports lookup of operators
1185 defined in a namespace and imported with a `using' directive, operators
1186 defined in the global scope, operators imported implicitly from an
1187 anonymous namespace, and the ADL operators mentioned in the previous
1189 GDB now also supports proper overload resolution for all the previously
1190 mentioned flavors of operators.
1192 ** static const class members
1194 Printing of static const class members that are initialized in the
1195 class definition has been fixed.
1197 * Windows Thread Information Block access.
1199 On Windows targets, GDB now supports displaying the Windows Thread
1200 Information Block (TIB) structure. This structure is visible either
1201 by using the new command `info w32 thread-information-block' or, by
1202 dereferencing the new convenience variable named `$_tlb', a
1203 thread-specific pointer to the TIB. This feature is also supported
1204 when remote debugging using GDBserver.
1206 * Static tracepoints
1208 Static tracepoints are calls in the user program into a tracing
1209 library. One such library is a port of the LTTng kernel tracer to
1210 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1211 When debugging with GDBserver, GDB now supports combining the GDB
1212 tracepoint machinery with such libraries. For example: the user can
1213 use GDB to probe a static tracepoint marker (a call from the user
1214 program into the tracing library) with the new "strace" command (see
1215 "New commands" below). This creates a "static tracepoint" in the
1216 breakpoint list, that can be manipulated with the same feature set
1217 as fast and regular tracepoints. E.g., collect registers, local and
1218 global variables, collect trace state variables, and define
1219 tracepoint conditions. In addition, the user can collect extra
1220 static tracepoint marker specific data, by collecting the new
1221 $_sdata internal variable. When analyzing the trace buffer, you can
1222 inspect $_sdata like any other variable available to GDB. For more
1223 information, see the "Tracepoints" chapter in GDB user manual. New
1224 remote packets have been defined to support static tracepoints, see
1225 the "New remote packets" section below.
1227 * Better reconstruction of tracepoints after disconnected tracing
1229 GDB will attempt to download the original source form of tracepoint
1230 definitions when starting a trace run, and then will upload these
1231 upon reconnection to the target, resulting in a more accurate
1232 reconstruction of the tracepoints that are in use on the target.
1236 You can now exercise direct control over the ways that GDB can
1237 affect your program. For instance, you can disallow the setting of
1238 breakpoints, so that the program can run continuously (assuming
1239 non-stop mode). In addition, the "observer" variable is available
1240 to switch all of the different controls; in observer mode, GDB
1241 cannot affect the target's behavior at all, which is useful for
1242 tasks like diagnosing live systems in the field.
1244 * The new convenience variable $_thread holds the number of the
1247 * New remote packets
1251 Return the address of the Windows Thread Information Block of a given thread.
1255 In response to several of the tracepoint packets, the target may now
1256 also respond with a number of intermediate `qRelocInsn' request
1257 packets before the final result packet, to have GDB handle
1258 relocating an instruction to execute at a different address. This
1259 is particularly useful for stubs that support fast tracepoints. GDB
1260 reports support for this feature in the qSupported packet.
1264 List static tracepoint markers in the target program.
1268 List static tracepoint markers at a given address in the target
1271 qXfer:statictrace:read
1273 Read the static trace data collected (by a `collect $_sdata'
1274 tracepoint action). The remote stub reports support for this packet
1275 to gdb's qSupported query.
1279 Send the current settings of GDB's permission flags.
1283 Send part of the source (textual) form of a tracepoint definition,
1284 which includes location, conditional, and action list.
1286 * The source command now accepts a -s option to force searching for the
1287 script in the source search path even if the script name specifies
1290 * New features in the GDB remote stub, GDBserver
1292 - GDBserver now support tracepoints (including fast tracepoints, and
1293 static tracepoints). The feature is currently supported by the
1294 i386-linux and amd64-linux builds. See the "Tracepoints support
1295 in gdbserver" section in the manual for more information.
1297 GDBserver JIT compiles the tracepoint's conditional agent
1298 expression bytecode into native code whenever possible for low
1299 overhead dynamic tracepoints conditionals. For such tracepoints,
1300 an expression that examines program state is evaluated when the
1301 tracepoint is reached, in order to determine whether to capture
1302 trace data. If the condition is simple and false, processing the
1303 tracepoint finishes very quickly and no data is gathered.
1305 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1306 for static tracepoints support.
1308 - GDBserver now supports x86_64 Windows 64-bit debugging.
1310 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1311 it understands register description.
1313 * The --batch flag now disables pagination and queries.
1315 * X86 general purpose registers
1317 GDB now supports reading/writing byte, word and double-word x86
1318 general purpose registers directly. This means you can use, say,
1319 $ah or $ax to refer, respectively, to the byte register AH and
1320 16-bit word register AX that are actually portions of the 32-bit
1321 register EAX or 64-bit register RAX.
1323 * The `commands' command now accepts a range of breakpoints to modify.
1324 A plain `commands' following a command that creates multiple
1325 breakpoints affects all the breakpoints set by that command. This
1326 applies to breakpoints set by `rbreak', and also applies when a
1327 single `break' command creates multiple breakpoints (e.g.,
1328 breakpoints on overloaded c++ functions).
1330 * The `rbreak' command now accepts a filename specification as part of
1331 its argument, limiting the functions selected by the regex to those
1332 in the specified file.
1334 * Support for remote debugging Windows and SymbianOS shared libraries
1335 from Unix hosts has been improved. Non Windows GDB builds now can
1336 understand target reported file names that follow MS-DOS based file
1337 system semantics, such as file names that include drive letters and
1338 use the backslash character as directory separator. This makes it
1339 possible to transparently use the "set sysroot" and "set
1340 solib-search-path" on Unix hosts to point as host copies of the
1341 target's shared libraries. See the new command "set
1342 target-file-system-kind" described below, and the "Commands to
1343 specify files" section in the user manual for more information.
1347 eval template, expressions...
1348 Convert the values of one or more expressions under the control
1349 of the string template to a command line, and call it.
1351 set target-file-system-kind unix|dos-based|auto
1352 show target-file-system-kind
1353 Set or show the assumed file system kind for target reported file
1356 save breakpoints <filename>
1357 Save all current breakpoint definitions to a file suitable for use
1358 in a later debugging session. To read the saved breakpoint
1359 definitions, use the `source' command.
1361 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1364 info static-tracepoint-markers
1365 Display information about static tracepoint markers in the target.
1367 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1368 Define a static tracepoint by probing a marker at the given
1369 function, line, address, or marker ID.
1373 Enable and disable observer mode.
1375 set may-write-registers on|off
1376 set may-write-memory on|off
1377 set may-insert-breakpoints on|off
1378 set may-insert-tracepoints on|off
1379 set may-insert-fast-tracepoints on|off
1380 set may-interrupt on|off
1381 Set individual permissions for GDB effects on the target. Note that
1382 some of these settings can have undesirable or surprising
1383 consequences, particularly when changed in the middle of a session.
1384 For instance, disabling the writing of memory can prevent
1385 breakpoints from being inserted, cause single-stepping to fail, or
1386 even crash your program, if you disable after breakpoints have been
1387 inserted. However, GDB should not crash.
1389 set record memory-query on|off
1390 show record memory-query
1391 Control whether to stop the inferior if memory changes caused
1392 by an instruction cannot be recorded.
1397 The disassemble command now supports "start,+length" form of two arguments.
1401 ** GDB now provides a new directory location, called the python directory,
1402 where Python scripts written for GDB can be installed. The location
1403 of that directory is <data-directory>/python, where <data-directory>
1404 is the GDB data directory. For more details, see section `Scripting
1405 GDB using Python' in the manual.
1407 ** The GDB Python API now has access to breakpoints, symbols, symbol
1408 tables, program spaces, inferiors, threads and frame's code blocks.
1409 Additionally, GDB Parameters can now be created from the API, and
1410 manipulated via set/show in the CLI.
1412 ** New functions gdb.target_charset, gdb.target_wide_charset,
1413 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1415 ** New exception gdb.GdbError.
1417 ** Pretty-printers are now also looked up in the current program space.
1419 ** Pretty-printers can now be individually enabled and disabled.
1421 ** GDB now looks for names of Python scripts to auto-load in a
1422 special section named `.debug_gdb_scripts', in addition to looking
1423 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1425 * Tracepoint actions were unified with breakpoint commands. In particular,
1426 there are no longer differences in "info break" output for breakpoints and
1427 tracepoints and the "commands" command can be used for both tracepoints and
1428 regular breakpoints.
1432 ARM Symbian arm*-*-symbianelf*
1434 * D language support.
1435 GDB now supports debugging programs written in the D programming
1438 * GDB now supports the extended ptrace interface for PowerPC which is
1439 available since Linux kernel version 2.6.34. This automatically enables
1440 any hardware breakpoints and additional hardware watchpoints available in
1441 the processor. The old ptrace interface exposes just one hardware
1442 watchpoint and no hardware breakpoints.
1444 * GDB is now able to use the Data Value Compare (DVC) register available on
1445 embedded PowerPC processors to implement in hardware simple watchpoint
1446 conditions of the form:
1448 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1450 This works in native GDB running on Linux kernels with the extended ptrace
1451 interface mentioned above.
1453 *** Changes in GDB 7.1
1457 ** Namespace Support
1459 GDB now supports importing of namespaces in C++. This enables the
1460 user to inspect variables from imported namespaces. Support for
1461 namepace aliasing has also been added. So, if a namespace is
1462 aliased in the current scope (e.g. namepace C=A; ) the user can
1463 print variables using the alias (e.g. (gdb) print C::x).
1467 All known bugs relating to the printing of virtual base class were
1468 fixed. It is now possible to call overloaded static methods using a
1473 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1474 and reinterpret_cast<> are now handled by the C++ expression parser.
1478 Xilinx MicroBlaze microblaze-*-*
1483 Xilinx MicroBlaze microblaze
1486 * Multi-program debugging.
1488 GDB now has support for multi-program (a.k.a. multi-executable or
1489 multi-exec) debugging. This allows for debugging multiple inferiors
1490 simultaneously each running a different program under the same GDB
1491 session. See "Debugging Multiple Inferiors and Programs" in the
1492 manual for more information. This implied some user visible changes
1493 in the multi-inferior support. For example, "info inferiors" now
1494 lists inferiors that are not running yet or that have exited
1495 already. See also "New commands" and "New options" below.
1497 * New tracing features
1499 GDB's tracepoint facility now includes several new features:
1501 ** Trace state variables
1503 GDB tracepoints now include support for trace state variables, which
1504 are variables managed by the target agent during a tracing
1505 experiment. They are useful for tracepoints that trigger each
1506 other, so for instance one tracepoint can count hits in a variable,
1507 and then a second tracepoint has a condition that is true when the
1508 count reaches a particular value. Trace state variables share the
1509 $-syntax of GDB convenience variables, and can appear in both
1510 tracepoint actions and condition expressions. Use the "tvariable"
1511 command to create, and "info tvariables" to view; see "Trace State
1512 Variables" in the manual for more detail.
1516 GDB now includes an option for defining fast tracepoints, which
1517 targets may implement more efficiently, such as by installing a jump
1518 into the target agent rather than a trap instruction. The resulting
1519 speedup can be by two orders of magnitude or more, although the
1520 tradeoff is that some program locations on some target architectures
1521 might not allow fast tracepoint installation, for instance if the
1522 instruction to be replaced is shorter than the jump. To request a
1523 fast tracepoint, use the "ftrace" command, with syntax identical to
1524 the regular trace command.
1526 ** Disconnected tracing
1528 It is now possible to detach GDB from the target while it is running
1529 a trace experiment, then reconnect later to see how the experiment
1530 is going. In addition, a new variable disconnected-tracing lets you
1531 tell the target agent whether to continue running a trace if the
1532 connection is lost unexpectedly.
1536 GDB now has the ability to save the trace buffer into a file, and
1537 then use that file as a target, similarly to you can do with
1538 corefiles. You can select trace frames, print data that was
1539 collected in them, and use tstatus to display the state of the
1540 tracing run at the moment that it was saved. To create a trace
1541 file, use "tsave <filename>", and to use it, do "target tfile
1544 ** Circular trace buffer
1546 You can ask the target agent to handle the trace buffer as a
1547 circular buffer, discarding the oldest trace frames to make room for
1548 newer ones, by setting circular-trace-buffer to on. This feature may
1549 not be available for all target agents.
1554 The disassemble command, when invoked with two arguments, now requires
1555 the arguments to be comma-separated.
1558 The info variables command now displays variable definitions. Files
1559 which only declare a variable are not shown.
1562 The source command is now capable of sourcing Python scripts.
1563 This feature is dependent on the debugger being build with Python
1566 Related to this enhancement is also the introduction of a new command
1567 "set script-extension" (see below).
1569 * New commands (for set/show, see "New options" below)
1571 record save [<FILENAME>]
1572 Save a file (in core file format) containing the process record
1573 execution log for replay debugging at a later time.
1575 record restore <FILENAME>
1576 Restore the process record execution log that was saved at an
1577 earlier time, for replay debugging.
1579 add-inferior [-copies <N>] [-exec <FILENAME>]
1582 clone-inferior [-copies <N>] [ID]
1583 Make a new inferior ready to execute the same program another
1584 inferior has loaded.
1589 maint info program-spaces
1590 List the program spaces loaded into GDB.
1592 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1593 show remote interrupt-sequence
1594 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1595 as the sequence to the remote target in order to interrupt the execution.
1596 Ctrl-C is a default. Some system prefers BREAK which is high level of
1597 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1598 Magic SysRq g. It is BREAK signal and character 'g'.
1600 set remote interrupt-on-connect [on | off]
1601 show remote interrupt-on-connect
1602 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1603 remote target when gdb connects to it. This is needed when you debug
1606 set remotebreak [on | off]
1608 Deprecated. Use "set/show remote interrupt-sequence" instead.
1610 tvariable $NAME [ = EXP ]
1611 Create or modify a trace state variable.
1614 List trace state variables and their values.
1616 delete tvariable $NAME ...
1617 Delete one or more trace state variables.
1620 Evaluate the given expressions without collecting anything into the
1621 trace buffer. (Valid in tracepoint actions only.)
1623 ftrace FN / FILE:LINE / *ADDR
1624 Define a fast tracepoint at the given function, line, or address.
1626 * New expression syntax
1628 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1629 GDB now parses 0b101010 identically with 42.
1633 set follow-exec-mode new|same
1634 show follow-exec-mode
1635 Control whether GDB reuses the same inferior across an exec call or
1636 creates a new one. This is useful to be able to restart the old
1637 executable after the inferior having done an exec call.
1639 set default-collect EXPR, ...
1640 show default-collect
1641 Define a list of expressions to be collected at each tracepoint.
1642 This is a useful way to ensure essential items are not overlooked,
1643 such as registers or a critical global variable.
1645 set disconnected-tracing
1646 show disconnected-tracing
1647 If set to 1, the target is instructed to continue tracing if it
1648 loses its connection to GDB. If 0, the target is to stop tracing
1651 set circular-trace-buffer
1652 show circular-trace-buffer
1653 If set to on, the target is instructed to use a circular trace buffer
1654 and discard the oldest trace frames instead of stopping the trace due
1655 to a full trace buffer. If set to off, the trace stops when the buffer
1656 fills up. Some targets may not support this.
1658 set script-extension off|soft|strict
1659 show script-extension
1660 If set to "off", the debugger does not perform any script language
1661 recognition, and all sourced files are assumed to be GDB scripts.
1662 If set to "soft" (the default), files are sourced according to
1663 filename extension, falling back to GDB scripts if the first
1665 If set to "strict", files are sourced according to filename extension.
1667 set ada trust-PAD-over-XVS on|off
1668 show ada trust-PAD-over-XVS
1669 If off, activate a workaround against a bug in the debugging information
1670 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1671 the GCC sources for more information about the GNAT encoding and
1672 PAD types in particular). It is always safe to set this option to
1673 off, but this introduces a slight performance penalty. The default
1676 * Python API Improvements
1678 ** GDB provides the new class gdb.LazyString. This is useful in
1679 some pretty-printing cases. The new method gdb.Value.lazy_string
1680 provides a simple way to create objects of this type.
1682 ** The fields returned by gdb.Type.fields now have an
1683 `is_base_class' attribute.
1685 ** The new method gdb.Type.range returns the range of an array type.
1687 ** The new method gdb.parse_and_eval can be used to parse and
1688 evaluate an expression.
1690 * New remote packets
1693 Define a trace state variable.
1696 Get the current value of a trace state variable.
1699 Set desired tracing behavior upon disconnection.
1702 Set the trace buffer to be linear or circular.
1705 Get data about the tracepoints currently in use.
1709 Process record now works correctly with hardware watchpoints.
1711 Multiple bug fixes have been made to the mips-irix port, making it
1712 much more reliable. In particular:
1713 - Debugging threaded applications is now possible again. Previously,
1714 GDB would hang while starting the program, or while waiting for
1715 the program to stop at a breakpoint.
1716 - Attaching to a running process no longer hangs.
1717 - An error occurring while loading a core file has been fixed.
1718 - Changing the value of the PC register now works again. This fixes
1719 problems observed when using the "jump" command, or when calling
1720 a function from GDB, or even when assigning a new value to $pc.
1721 - With the "finish" and "return" commands, the return value for functions
1722 returning a small array is now correctly printed.
1723 - It is now possible to break on shared library code which gets executed
1724 during a shared library init phase (code executed while executing
1725 their .init section). Previously, the breakpoint would have no effect.
1726 - GDB is now able to backtrace through the signal handler for
1727 non-threaded programs.
1729 PIE (Position Independent Executable) programs debugging is now supported.
1730 This includes debugging execution of PIC (Position Independent Code) shared
1731 libraries although for that, it should be possible to run such libraries as an
1734 *** Changes in GDB 7.0
1736 * GDB now has an interface for JIT compilation. Applications that
1737 dynamically generate code can create symbol files in memory and register
1738 them with GDB. For users, the feature should work transparently, and
1739 for JIT developers, the interface is documented in the GDB manual in the
1740 "JIT Compilation Interface" chapter.
1742 * Tracepoints may now be conditional. The syntax is as for
1743 breakpoints; either an "if" clause appended to the "trace" command,
1744 or the "condition" command is available. GDB sends the condition to
1745 the target for evaluation using the same bytecode format as is used
1746 for tracepoint actions.
1748 * The disassemble command now supports: an optional /r modifier, print the
1749 raw instructions in hex as well as in symbolic form, and an optional /m
1750 modifier to print mixed source+assembly.
1752 * Process record and replay
1754 In a architecture environment that supports ``process record and
1755 replay'', ``process record and replay'' target can record a log of
1756 the process execution, and replay it with both forward and reverse
1759 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1760 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1761 set execution-direction {forward|reverse}, for targets that support
1764 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1765 feature is available with a native GDB running on kernel version
1768 * GDB now has support for multi-byte and wide character sets on the
1769 target. Strings whose character type is wchar_t, char16_t, or
1770 char32_t are now correctly printed. GDB supports wide- and unicode-
1771 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1772 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1773 `printf'. This feature requires iconv to work properly; if your
1774 system does not have a working iconv, GDB can use GNU libiconv. See
1775 the installation instructions for more information.
1777 * GDB now supports automatic retrieval of shared library files from
1778 remote targets. To use this feature, specify a system root that begins
1779 with the `remote:' prefix, either via the `set sysroot' command or via
1780 the `--with-sysroot' configure-time option.
1782 * "info sharedlibrary" now takes an optional regex of libraries to show,
1783 and it now reports if a shared library has no debugging information.
1785 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1786 now complete on file names.
1788 * When completing in expressions, gdb will attempt to limit
1789 completions to allowable structure or union fields, where appropriate.
1790 For instance, consider:
1792 # struct example { int f1; double f2; };
1793 # struct example variable;
1796 If the user types TAB at the end of this command line, the available
1797 completions will be "f1" and "f2".
1799 * Inlined functions are now supported. They show up in backtraces, and
1800 the "step", "next", and "finish" commands handle them automatically.
1802 * GDB now supports the token-splicing (##) and stringification (#)
1803 operators when expanding macros. It also supports variable-arity
1806 * GDB now supports inspecting extra signal information, exported by
1807 the new $_siginfo convenience variable. The feature is currently
1808 implemented on linux ARM, i386 and amd64.
1810 * GDB can now display the VFP floating point registers and NEON vector
1811 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1812 can provide these registers (requires Linux 2.6.30 or later). Remote
1813 and simulator targets may also provide them.
1815 * New remote packets
1818 Search memory for a sequence of bytes.
1821 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1822 operation over reliable transport links. Use of this packet is
1823 controlled by the `set remote noack-packet' command.
1826 Kill the process with the specified process ID. Use this in preference
1827 to `k' when multiprocess protocol extensions are supported.
1830 Obtains additional operating system information
1834 Read or write additional signal information.
1836 * Removed remote protocol undocumented extension
1838 An undocumented extension to the remote protocol's `S' stop reply
1839 packet that permited the stub to pass a process id was removed.
1840 Remote servers should use the `T' stop reply packet instead.
1842 * GDB now supports multiple function calling conventions according to the
1843 DWARF-2 DW_AT_calling_convention function attribute.
1845 * The SH target utilizes the aforementioned change to distinguish between gcc
1846 and Renesas calling convention. It also adds the new CLI commands
1847 `set/show sh calling-convention'.
1849 * GDB can now read compressed debug sections, as produced by GNU gold
1850 with the --compress-debug-sections=zlib flag.
1852 * 64-bit core files are now supported on AIX.
1854 * Thread switching is now supported on Tru64.
1856 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1857 which will be allocated using malloc later in program execution.
1859 * The qXfer:libraries:read remote procotol packet now allows passing a
1860 list of section offsets.
1862 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1863 conditions handling signals delivered during attach or thread creation
1864 have also been fixed.
1866 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1867 From the user's standpoint, all unqualified instances of True and False
1868 are treated as the standard definitions, regardless of context.
1870 * GDB now parses C++ symbol and type names more flexibly. For
1873 template<typename T> class C { };
1876 GDB will now correctly handle all of:
1878 ptype C<char const *>
1879 ptype C<char const*>
1880 ptype C<const char *>
1881 ptype C<const char*>
1883 * New features in the GDB remote stub, gdbserver
1885 - The "--wrapper" command-line argument tells gdbserver to use a
1886 wrapper program to launch programs for debugging.
1888 - On PowerPC and S/390 targets, it is now possible to use a single
1889 gdbserver executable to debug both 32-bit and 64-bit programs.
1890 (This requires gdbserver itself to be built as a 64-bit executable.)
1892 - gdbserver uses the new noack protocol mode for TCP connections to
1893 reduce communications latency, if also supported and enabled in GDB.
1895 - Support for the sparc64-linux-gnu target is now included in
1898 - The amd64-linux build of gdbserver now supports debugging both
1899 32-bit and 64-bit programs.
1901 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1902 now support hardware watchpoints, and will use them automatically
1907 GDB now has support for scripting using Python. Whether this is
1908 available is determined at configure time.
1910 New GDB commands can now be written in Python.
1912 * Ada tasking support
1914 Ada tasks can now be inspected in GDB. The following commands have
1918 Print the list of Ada tasks.
1920 Print detailed information about task number N.
1922 Print the task number of the current task.
1924 Switch the context of debugging to task number N.
1926 * Support for user-defined prefixed commands. The "define" command can
1927 add new commands to existing prefixes, e.g. "target".
1929 * Multi-inferior, multi-process debugging.
1931 GDB now has generalized support for multi-inferior debugging. See
1932 "Debugging Multiple Inferiors" in the manual for more information.
1933 Although availability still depends on target support, the command
1934 set is more uniform now. The GNU/Linux specific multi-forks support
1935 has been migrated to this new framework. This implied some user
1936 visible changes; see "New commands" and also "Removed commands"
1939 * Target descriptions can now describe the target OS ABI. See the
1940 "Target Description Format" section in the user manual for more
1943 * Target descriptions can now describe "compatible" architectures
1944 to indicate that the target can execute applications for a different
1945 architecture in addition to those for the main target architecture.
1946 See the "Target Description Format" section in the user manual for
1949 * Multi-architecture debugging.
1951 GDB now includes general supports for debugging applications on
1952 hybrid systems that use more than one single processor architecture
1953 at the same time. Each such hybrid architecture still requires
1954 specific support to be added. The only hybrid architecture supported
1955 in this version of GDB is the Cell Broadband Engine.
1957 * GDB now supports integrated debugging of Cell/B.E. applications that
1958 use both the PPU and SPU architectures. To enable support for hybrid
1959 Cell/B.E. debugging, you need to configure GDB to support both the
1960 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1961 --enable-targets configure option.
1963 * Non-stop mode debugging.
1965 For some targets, GDB now supports an optional mode of operation in
1966 which you can examine stopped threads while other threads continue
1967 to execute freely. This is referred to as non-stop mode, with the
1968 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1969 section in the user manual for more information.
1971 To be able to support remote non-stop debugging, a remote stub needs
1972 to implement the non-stop mode remote protocol extensions, as
1973 described in the "Remote Non-Stop" section of the user manual. The
1974 GDB remote stub, gdbserver, has been adjusted to support these
1975 extensions on linux targets.
1977 * New commands (for set/show, see "New options" below)
1979 catch syscall [NAME(S) | NUMBER(S)]
1980 Catch system calls. Arguments, which should be names of system
1981 calls or their numbers, mean catch only those syscalls. Without
1982 arguments, every syscall will be caught. When the inferior issues
1983 any of the specified syscalls, GDB will stop and announce the system
1984 call, both when it is called and when its call returns. This
1985 feature is currently available with a native GDB running on the
1986 Linux Kernel, under the following architectures: x86, x86_64,
1987 PowerPC and PowerPC64.
1989 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1991 Search memory for a sequence of bytes.
1993 maint set python print-stack
1994 maint show python print-stack
1995 Show a stack trace when an error is encountered in a Python script.
1998 Invoke CODE by passing it to the Python interpreter.
2003 These allow macros to be defined, undefined, and listed
2007 Show operating system information about processes.
2010 List the inferiors currently under GDB's control.
2013 Switch focus to inferior number NUM.
2016 Detach from inferior number NUM.
2019 Kill inferior number NUM.
2023 set spu stop-on-load
2024 show spu stop-on-load
2025 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2027 set spu auto-flush-cache
2028 show spu auto-flush-cache
2029 Control whether to automatically flush the software-managed cache
2030 during Cell/B.E. debugging.
2032 set sh calling-convention
2033 show sh calling-convention
2034 Control the calling convention used when calling SH target functions.
2037 show debug timestamp
2038 Control display of timestamps with GDB debugging output.
2040 set disassemble-next-line
2041 show disassemble-next-line
2042 Control display of disassembled source lines or instructions when
2045 set remote noack-packet
2046 show remote noack-packet
2047 Set/show the use of remote protocol QStartNoAckMode packet. See above
2048 under "New remote packets."
2050 set remote query-attached-packet
2051 show remote query-attached-packet
2052 Control use of remote protocol `qAttached' (query-attached) packet.
2054 set remote read-siginfo-object
2055 show remote read-siginfo-object
2056 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2059 set remote write-siginfo-object
2060 show remote write-siginfo-object
2061 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2064 set remote reverse-continue
2065 show remote reverse-continue
2066 Control use of remote protocol 'bc' (reverse-continue) packet.
2068 set remote reverse-step
2069 show remote reverse-step
2070 Control use of remote protocol 'bs' (reverse-step) packet.
2072 set displaced-stepping
2073 show displaced-stepping
2074 Control displaced stepping mode. Displaced stepping is a way to
2075 single-step over breakpoints without removing them from the debuggee.
2076 Also known as "out-of-line single-stepping".
2079 show debug displaced
2080 Control display of debugging info for displaced stepping.
2082 maint set internal-error
2083 maint show internal-error
2084 Control what GDB does when an internal error is detected.
2086 maint set internal-warning
2087 maint show internal-warning
2088 Control what GDB does when an internal warning is detected.
2093 Use a wrapper program to launch programs for debugging.
2095 set multiple-symbols (all|ask|cancel)
2096 show multiple-symbols
2097 The value of this variable can be changed to adjust the debugger behavior
2098 when an expression or a breakpoint location contains an ambiguous symbol
2099 name (an overloaded function name, for instance).
2101 set breakpoint always-inserted
2102 show breakpoint always-inserted
2103 Keep breakpoints always inserted in the target, as opposed to inserting
2104 them when resuming the target, and removing them when the target stops.
2105 This option can improve debugger performance on slow remote targets.
2107 set arm fallback-mode (arm|thumb|auto)
2108 show arm fallback-mode
2109 set arm force-mode (arm|thumb|auto)
2111 These commands control how ARM GDB determines whether instructions
2112 are ARM or Thumb. The default for both settings is auto, which uses
2113 the current CPSR value for instructions without symbols; previous
2114 versions of GDB behaved as if "set arm fallback-mode arm".
2116 set disable-randomization
2117 show disable-randomization
2118 Standalone programs run with the virtual address space randomization enabled
2119 by default on some platforms. This option keeps the addresses stable across
2120 multiple debugging sessions.
2124 Control whether other threads are stopped or not when some thread hits
2129 Requests that asynchronous execution is enabled in the target, if available.
2130 In this case, it's possible to resume target in the background, and interact
2131 with GDB while the target is running. "show target-async" displays the
2132 current state of asynchronous execution of the target.
2134 set target-wide-charset
2135 show target-wide-charset
2136 The target-wide-charset is the name of the character set that GDB
2137 uses when printing characters whose type is wchar_t.
2139 set tcp auto-retry (on|off)
2141 set tcp connect-timeout
2142 show tcp connect-timeout
2143 These commands allow GDB to retry failed TCP connections to a remote stub
2144 with a specified timeout period; this is useful if the stub is launched
2145 in parallel with GDB but may not be ready to accept connections immediately.
2147 set libthread-db-search-path
2148 show libthread-db-search-path
2149 Control list of directories which GDB will search for appropriate
2152 set schedule-multiple (on|off)
2153 show schedule-multiple
2154 Allow GDB to resume all threads of all processes or only threads of
2155 the current process.
2159 Use more aggressive caching for accesses to the stack. This improves
2160 performance of remote debugging (particularly backtraces) without
2161 affecting correctness.
2163 set interactive-mode (on|off|auto)
2164 show interactive-mode
2165 Control whether GDB runs in interactive mode (on) or not (off).
2166 When in interactive mode, GDB waits for the user to answer all
2167 queries. Otherwise, GDB does not wait and assumes the default
2168 answer. When set to auto (the default), GDB determines which
2169 mode to use based on the stdin settings.
2174 For program forks, this is replaced by the new more generic `info
2175 inferiors' command. To list checkpoints, you can still use the
2176 `info checkpoints' command, which was an alias for the `info forks'
2180 Replaced by the new `inferior' command. To switch between
2181 checkpoints, you can still use the `restart' command, which was an
2182 alias for the `fork' command.
2185 This is removed, since some targets don't have a notion of
2186 processes. To switch between processes, you can still use the
2187 `inferior' command using GDB's own inferior number.
2190 For program forks, this is replaced by the new more generic `kill
2191 inferior' command. To delete a checkpoint, you can still use the
2192 `delete checkpoint' command, which was an alias for the `delete
2196 For program forks, this is replaced by the new more generic `detach
2197 inferior' command. To detach a checkpoint, you can still use the
2198 `detach checkpoint' command, which was an alias for the `detach
2201 * New native configurations
2203 x86/x86_64 Darwin i[34567]86-*-darwin*
2205 x86_64 MinGW x86_64-*-mingw*
2209 Lattice Mico32 lm32-*
2210 x86 DICOS i[34567]86-*-dicos*
2211 x86_64 DICOS x86_64-*-dicos*
2214 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2215 (mingw32ce) debugging.
2221 These commands were actually not implemented on any target.
2223 *** Changes in GDB 6.8
2225 * New native configurations
2227 NetBSD/hppa hppa*-*netbsd*
2228 Xtensa GNU/Linux xtensa*-*-linux*
2232 NetBSD/hppa hppa*-*-netbsd*
2233 Xtensa GNU/Lunux xtensa*-*-linux*
2235 * Change in command line behavior -- corefiles vs. process ids.
2237 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2238 attaching to process NUMBER fails, GDB no longer attempts to open a
2239 core file named NUMBER. Attaching to a program using the -c option
2240 is no longer supported. Instead, use the '-p' or '--pid' options.
2242 * GDB can now be built as a native debugger for debugging Windows x86
2243 (mingw32) Portable Executable (PE) programs.
2245 * Pending breakpoints no longer change their number when their address
2248 * GDB now supports breakpoints with multiple locations,
2249 including breakpoints on C++ constructors, inside C++ templates,
2250 and in inlined functions.
2252 * GDB's ability to debug optimized code has been improved. GDB more
2253 accurately identifies function bodies and lexical blocks that occupy
2254 more than one contiguous range of addresses.
2256 * Target descriptions can now describe registers for PowerPC.
2258 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2259 registers on PowerPC targets.
2261 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2262 targets even when the libthread_db library is not available.
2264 * The GDB remote stub, gdbserver, now supports the new file transfer
2265 commands (remote put, remote get, and remote delete).
2267 * The GDB remote stub, gdbserver, now supports run and attach in
2268 extended-remote mode.
2270 * hppa*64*-*-hpux11* target broken
2271 The debugger is unable to start a program and fails with the following
2272 error: "Error trying to get information about dynamic linker".
2273 The gdb-6.7 release is also affected.
2275 * GDB now supports the --enable-targets= configure option to allow
2276 building a single GDB executable that supports multiple remote
2277 target architectures.
2279 * GDB now supports debugging C and C++ programs which use the
2280 Decimal Floating Point extension. In addition, the PowerPC target
2281 now has a set of pseudo-registers to inspect decimal float values
2282 stored in two consecutive float registers.
2284 * The -break-insert MI command can optionally create pending
2287 * Improved support for debugging Ada
2288 Many improvements to the Ada language support have been made. These
2290 - Better support for Ada2005 interface types
2291 - Improved handling of arrays and slices in general
2292 - Better support for Taft-amendment types
2293 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2295 - Improved command completion in Ada
2298 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2303 set print frame-arguments (all|scalars|none)
2304 show print frame-arguments
2305 The value of this variable can be changed to control which argument
2306 values should be printed by the debugger when displaying a frame.
2311 Transfer files to and from a remote target, and delete remote files.
2318 Transfer files to and from a remote target, and delete remote files.
2320 * New remote packets
2327 Open, close, read, write, and delete files on the remote system.
2330 Attach to an existing process on the remote system, in extended-remote
2334 Run a new process on the remote system, in extended-remote mode.
2336 *** Changes in GDB 6.7
2338 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2339 bfd, libiberty and opcodes, as revealed by static analysis donated by
2340 Coverity, Inc. (http://scan.coverity.com).
2342 * When looking up multiply-defined global symbols, GDB will now prefer the
2343 symbol definition in the current shared library if it was built using the
2344 -Bsymbolic linker option.
2346 * When the Text User Interface (TUI) is not configured, GDB will now
2347 recognize the -tui command-line option and print a message that the TUI
2350 * The GDB remote stub, gdbserver, now has lower overhead for high
2351 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2353 * GDB for MIPS targets now autodetects whether a remote target provides
2354 32-bit or 64-bit register values.
2356 * Support for C++ member pointers has been improved.
2358 * GDB now understands XML target descriptions, which specify the
2359 target's overall architecture. GDB can read a description from
2360 a local file or over the remote serial protocol.
2362 * Vectors of single-byte data use a new integer type which is not
2363 automatically displayed as character or string data.
2365 * The /s format now works with the print command. It displays
2366 arrays of single-byte integers and pointers to single-byte integers
2369 * Target descriptions can now describe target-specific registers,
2370 for architectures which have implemented the support (currently
2371 only ARM, M68K, and MIPS).
2373 * GDB and the GDB remote stub, gdbserver, now support the XScale
2376 * The GDB remote stub, gdbserver, has been updated to support
2377 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2378 has been rewritten to use the standard GDB remote protocol.
2380 * GDB can now step into C++ functions which are called through thunks.
2382 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2384 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2385 layout. It also supports a TextSeg= and DataSeg= response when only
2386 segment base addresses (rather than offsets) are available.
2388 * The /i format now outputs any trailing branch delay slot instructions
2389 immediately following the last instruction within the count specified.
2391 * The GDB remote protocol "T" stop reply packet now supports a
2392 "library" response. Combined with the new "qXfer:libraries:read"
2393 packet, this response allows GDB to debug shared libraries on targets
2394 where the operating system manages the list of loaded libraries (e.g.
2395 Windows and SymbianOS).
2397 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2398 (DLLs) on Windows and Windows CE targets.
2400 * GDB now supports a faster verification that a .debug file matches its binary
2401 according to its build-id signature, if the signature is present.
2407 Enable or disable hardware flow control (RTS/CTS) on the serial port
2408 when debugging using remote targets.
2410 set mem inaccessible-by-default
2411 show mem inaccessible-by-default
2412 If the target supplies a memory map, for instance via the remote
2413 protocol's "qXfer:memory-map:read" packet, setting this variable
2414 prevents GDB from accessing memory outside the memory map. This
2415 is useful for targets with memory mapped registers or which react
2416 badly to accesses of unmapped address space.
2418 set breakpoint auto-hw
2419 show breakpoint auto-hw
2420 If the target supplies a memory map, for instance via the remote
2421 protocol's "qXfer:memory-map:read" packet, setting this variable
2422 lets GDB use hardware breakpoints automatically for memory regions
2423 where it can not use software breakpoints. This covers both the
2424 "break" command and internal breakpoints used for other commands
2425 including "next" and "finish".
2428 catch exception unhandled
2429 Stop the program execution when Ada exceptions are raised.
2432 Stop the program execution when an Ada assertion failed.
2436 Set an alternate system root for target files. This is a more
2437 general version of "set solib-absolute-prefix", which is now
2438 an alias to "set sysroot".
2441 Provide extended SPU facility status information. This set of
2442 commands is available only when debugging the Cell/B.E. SPU
2445 * New native configurations
2447 OpenBSD/sh sh*-*openbsd*
2450 unset tdesc filename
2452 Use the specified local file as an XML target description, and do
2453 not query the target for its built-in description.
2457 OpenBSD/sh sh*-*-openbsd*
2458 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2459 Toshiba Media Processor mep-elf
2461 * New remote packets
2464 Ignore the specified signals; pass them directly to the debugged program
2465 without stopping other threads or reporting them to GDB.
2467 qXfer:features:read:
2468 Read an XML target description from the target, which describes its
2473 Read or write contents of an spufs file on the target system. These
2474 packets are available only on the Cell/B.E. SPU architecture.
2476 qXfer:libraries:read:
2477 Report the loaded shared libraries. Combined with new "T" packet
2478 response, this packet allows GDB to debug shared libraries on
2479 targets where the operating system manages the list of loaded
2480 libraries (e.g. Windows and SymbianOS).
2484 Support for these obsolete configurations has been removed.
2492 i[34567]86-*-lynxos*
2493 i[34567]86-*-netware*
2494 i[34567]86-*-sco3.2v5*
2495 i[34567]86-*-sco3.2v4*
2497 i[34567]86-*-sysv4.2*
2500 i[34567]86-*-unixware2*
2501 i[34567]86-*-unixware*
2510 * Other removed features
2517 Various m68k-only ROM monitors.
2524 Various Renesas ROM monitors and debugging interfaces for SH and
2529 Support for a Macraigor serial interface to on-chip debugging.
2530 GDB does not directly support the newer parallel or USB
2535 A debug information format. The predecessor to DWARF 2 and
2536 DWARF 3, which are still supported.
2538 Support for the HP aCC compiler on HP-UX/PA-RISC
2540 SOM-encapsulated symbolic debugging information, automatic
2541 invocation of pxdb, and the aCC custom C++ ABI. This does not
2542 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2543 with aCC can still be debugged on an assembly level.
2545 MIPS ".pdr" sections
2547 A MIPS-specific format used to describe stack frame layout
2548 in debugging information.
2552 GDB could work with an older version of Guile to debug
2553 the interpreter and Scheme programs running in it.
2555 set mips stack-arg-size
2556 set mips saved-gpreg-size
2558 Use "set mips abi" to control parameter passing for MIPS.
2560 *** Changes in GDB 6.6
2565 Cell Broadband Engine SPU spu-elf
2567 * GDB can now be configured as a cross-debugger targeting native Windows
2568 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2569 running on a Windows system over TCP/IP to debug Windows programs.
2571 * The GDB remote stub, gdbserver, has been updated to support Windows and
2572 Cygwin debugging. Both single-threaded and multi-threaded programs are
2575 * The "set trust-readonly-sections" command works again. This command was
2576 broken in GDB 6.3, 6.4, and 6.5.
2578 * The "load" command now supports writing to flash memory, if the remote
2579 stub provides the required support.
2581 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2582 longer requires symbolic debug information (e.g. DWARF-2).
2587 unset substitute-path
2588 show substitute-path
2589 Manage a list of substitution rules that GDB uses to rewrite the name
2590 of the directories where the sources are located. This can be useful
2591 for instance when the sources were moved to a different location
2592 between compilation and debugging.
2596 Print each CLI command as it is executed. Each command is prefixed with
2597 a number of `+' symbols representing the nesting depth.
2598 The source command now has a `-v' option to enable the same feature.
2602 The ARM Demon monitor support (RDP protocol, "target rdp").
2604 Kernel Object Display, an embedded debugging feature which only worked with
2605 an obsolete version of Cisco IOS.
2607 The 'set download-write-size' and 'show download-write-size' commands.
2609 * New remote packets
2612 Tell a stub about GDB client features, and request remote target features.
2613 The first feature implemented is PacketSize, which allows the target to
2614 specify the size of packets it can handle - to minimize the number of
2615 packets required and improve performance when connected to a remote
2619 Fetch an OS auxilliary vector from the remote stub. This packet is a
2620 more efficient replacement for qPart:auxv:read.
2622 qXfer:memory-map:read:
2623 Fetch a memory map from the remote stub, including information about
2624 RAM, ROM, and flash memory devices.
2629 Erase and program a flash memory device.
2631 * Removed remote packets
2634 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2635 used it, and only gdbserver implemented it.
2637 *** Changes in GDB 6.5
2641 Renesas M32C/M16C m32c-elf
2643 Morpho Technologies ms1 ms1-elf
2647 init-if-undefined Initialize a convenience variable, but
2648 only if it doesn't already have a value.
2650 The following commands are presently only implemented for native GNU/Linux:
2652 checkpoint Save a snapshot of the program state.
2654 restart <n> Return the program state to a
2655 previously saved state.
2657 info checkpoints List currently saved checkpoints.
2659 delete-checkpoint <n> Delete a previously saved checkpoint.
2661 set|show detach-on-fork Tell gdb whether to detach from a newly
2662 forked process, or to keep debugging it.
2664 info forks List forks of the user program that
2665 are available to be debugged.
2667 fork <n> Switch to debugging one of several
2668 forks of the user program that are
2669 available to be debugged.
2671 delete-fork <n> Delete a fork from the list of forks
2672 that are available to be debugged (and
2673 kill the forked process).
2675 detach-fork <n> Delete a fork from the list of forks
2676 that are available to be debugged (and
2677 allow the process to continue).
2681 Morpho Technologies ms2 ms1-elf
2683 * Improved Windows host support
2685 GDB now builds as a cross debugger hosted on i686-mingw32, including
2686 native console support, and remote communications using either
2687 network sockets or serial ports.
2689 * Improved Modula-2 language support
2691 GDB can now print most types in the Modula-2 syntax. This includes:
2692 basic types, set types, record types, enumerated types, range types,
2693 pointer types and ARRAY types. Procedure var parameters are correctly
2694 printed and hexadecimal addresses and character constants are also
2695 written in the Modula-2 syntax. Best results can be obtained by using
2696 GNU Modula-2 together with the -gdwarf-2 command line option.
2700 The ARM rdi-share module.
2702 The Netware NLM debug server.
2704 *** Changes in GDB 6.4
2706 * New native configurations
2708 OpenBSD/arm arm*-*-openbsd*
2709 OpenBSD/mips64 mips64-*-openbsd*
2713 Morpho Technologies ms1 ms1-elf
2715 * New command line options
2717 --batch-silent As for --batch, but totally silent.
2718 --return-child-result The debugger will exist with the same value
2719 the child (debugged) program exited with.
2720 --eval-command COMMAND, -ex COMMAND
2721 Execute a single GDB CLI command. This may be
2722 specified multiple times and in conjunction
2723 with the --command (-x) option.
2725 * Deprecated commands removed
2727 The following commands, that were deprecated in 2000, have been
2731 set|show arm disassembly-flavor set|show arm disassembler
2732 othernames set arm disassembler
2733 set|show remotedebug set|show debug remote
2734 set|show archdebug set|show debug arch
2735 set|show eventdebug set|show debug event
2738 * New BSD user-level threads support
2740 It is now possible to debug programs using the user-level threads
2741 library on OpenBSD and FreeBSD. Currently supported (target)
2744 FreeBSD/amd64 x86_64-*-freebsd*
2745 FreeBSD/i386 i386-*-freebsd*
2746 OpenBSD/i386 i386-*-openbsd*
2748 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2749 are not yet supported.
2751 * New support for Matsushita MN10300 w/sim added
2752 (Work in progress). mn10300-elf.
2754 * REMOVED configurations and files
2756 VxWorks and the XDR protocol *-*-vxworks
2757 Motorola MCORE mcore-*-*
2758 National Semiconductor NS32000 ns32k-*-*
2760 * New "set print array-indexes" command
2762 After turning this setting "on", GDB prints the index of each element
2763 when displaying arrays. The default is "off" to preserve the previous
2766 * VAX floating point support
2768 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2770 * User-defined command support
2772 In addition to using $arg0..$arg9 for argument passing, it is now possible
2773 to use $argc to determine now many arguments have been passed. See the
2774 section on user-defined commands in the user manual for more information.
2776 *** Changes in GDB 6.3:
2778 * New command line option
2780 GDB now accepts -l followed by a number to set the timeout for remote
2783 * GDB works with GCC -feliminate-dwarf2-dups
2785 GDB now supports a more compact representation of DWARF-2 debug
2786 information using DW_FORM_ref_addr references. These are produced
2787 by GCC with the option -feliminate-dwarf2-dups and also by some
2788 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2789 to use -feliminate-dwarf2-dups.
2791 * Internationalization
2793 When supported by the host system, GDB will be built with
2794 internationalization (libintl). The task of marking up the sources is
2795 continued, we're looking forward to our first translation.
2799 Initial support for debugging programs compiled with the GNAT
2800 implementation of the Ada programming language has been integrated
2801 into GDB. In this release, support is limited to expression evaluation.
2803 * New native configurations
2805 GNU/Linux/m32r m32r-*-linux-gnu
2809 GDB's remote protocol now includes support for the 'p' packet. This
2810 packet is used to fetch individual registers from a remote inferior.
2812 * END-OF-LIFE registers[] compatibility module
2814 GDB's internal register infrastructure has been completely rewritten.
2815 The new infrastructure making possible the implementation of key new
2816 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2819 GDB 6.3 will be the last release to include the the registers[]
2820 compatibility module that allowed out-of-date configurations to
2821 continue to work. This change directly impacts the following
2831 powerpc bdm protocol
2833 Unless there is activity to revive these configurations, they will be
2834 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2836 * OBSOLETE configurations and files
2838 Configurations that have been declared obsolete in this release have
2839 been commented out. Unless there is activity to revive these
2840 configurations, the next release of GDB will have their sources
2841 permanently REMOVED.
2850 *** Changes in GDB 6.2.1:
2852 * MIPS `break main; run' gave an heuristic-fence-post warning
2854 When attempting to run even a simple program, a warning about
2855 heuristic-fence-post being hit would be reported. This problem has
2858 * MIPS IRIX 'long double' crashed GDB
2860 When examining a long double variable, GDB would get a segmentation
2861 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2862 IRIX long double values).
2866 A bug in the VAX stack code was causing problems with the "next"
2867 command. This problem has been fixed.
2869 *** Changes in GDB 6.2:
2871 * Fix for ``many threads''
2873 On GNU/Linux systems that use the NPTL threads library, a program
2874 rapidly creating and deleting threads would confuse GDB leading to the
2877 ptrace: No such process.
2878 thread_db_get_info: cannot get thread info: generic error
2880 This problem has been fixed.
2882 * "-async" and "-noasync" options removed.
2884 Support for the broken "-noasync" option has been removed (it caused
2887 * New ``start'' command.
2889 This command runs the program until the begining of the main procedure.
2891 * New BSD Kernel Data Access Library (libkvm) interface
2893 Using ``target kvm'' it is now possible to debug kernel core dumps and
2894 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2895 platforms. Currently supported (native-only) configurations are:
2897 FreeBSD/amd64 x86_64-*-freebsd*
2898 FreeBSD/i386 i?86-*-freebsd*
2899 NetBSD/i386 i?86-*-netbsd*
2900 NetBSD/m68k m68*-*-netbsd*
2901 NetBSD/sparc sparc-*-netbsd*
2902 OpenBSD/amd64 x86_64-*-openbsd*
2903 OpenBSD/i386 i?86-*-openbsd*
2904 OpenBSD/m68k m68*-openbsd*
2905 OpenBSD/sparc sparc-*-openbsd*
2907 * Signal trampoline code overhauled
2909 Many generic problems with GDB's signal handling code have been fixed.
2910 These include: backtraces through non-contiguous stacks; recognition
2911 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2912 call; backtrace through a signal trampoline; step into and out of
2913 signal handlers; and single-stepping in the signal trampoline.
2915 Please note that kernel bugs are a limiting factor here. These
2916 features have been shown to work on an s390 GNU/Linux system that
2917 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2919 * Cygwin support for DWARF 2 added.
2921 * New native configurations
2923 GNU/Linux/hppa hppa*-*-linux*
2924 OpenBSD/hppa hppa*-*-openbsd*
2925 OpenBSD/m68k m68*-*-openbsd*
2926 OpenBSD/m88k m88*-*-openbsd*
2927 OpenBSD/powerpc powerpc-*-openbsd*
2928 NetBSD/vax vax-*-netbsd*
2929 OpenBSD/vax vax-*-openbsd*
2931 * END-OF-LIFE frame compatibility module
2933 GDB's internal frame infrastructure has been completely rewritten.
2934 The new infrastructure making it possible to support key new features
2935 including DWARF 2 Call Frame Information. To aid in the task of
2936 migrating old configurations to this new infrastructure, a
2937 compatibility module, that allowed old configurations to continue to
2938 work, was also included.
2940 GDB 6.2 will be the last release to include this frame compatibility
2941 module. This change directly impacts the following configurations:
2951 Unless there is activity to revive these configurations, they will be
2952 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2954 * REMOVED configurations and files
2956 Sun 3, running SunOS 3 m68*-*-sunos3*
2957 Sun 3, running SunOS 4 m68*-*-sunos4*
2958 Sun 2, running SunOS 3 m68000-*-sunos3*
2959 Sun 2, running SunOS 4 m68000-*-sunos4*
2960 Motorola 680x0 running LynxOS m68*-*-lynxos*
2961 AT&T 3b1/Unix pc m68*-att-*
2962 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2963 decstation mips-dec-* mips-little-*
2964 riscos mips-*-riscos* mips-*-sysv*
2965 sonymips mips-sony-*
2966 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2968 *** Changes in GDB 6.1.1:
2970 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2972 The TUI (Text-mode User Interface) is now built as part of a default
2973 GDB configuration. It is enabled by either selecting the TUI with the
2974 command line option "-i=tui" or by running the separate "gdbtui"
2975 program. For more information on the TUI, see the manual "Debugging
2978 * Pending breakpoint support (also included in GDB 6.1)
2980 Support has been added to allow you to specify breakpoints in shared
2981 libraries that have not yet been loaded. If a breakpoint location
2982 cannot be found, and the "breakpoint pending" option is set to auto,
2983 GDB queries you if you wish to make the breakpoint pending on a future
2984 shared-library load. If and when GDB resolves the breakpoint symbol,
2985 the pending breakpoint is removed as one or more regular breakpoints
2988 Pending breakpoints are very useful for GCJ Java debugging.
2990 * Fixed ISO-C build problems
2992 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2993 non ISO-C code that stopped them being built using a more strict ISO-C
2994 compiler (e.g., IBM's C compiler).
2996 * Fixed build problem on IRIX 5
2998 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2999 wasn't able to compile compile on an IRIX 5 system.
3001 * Added execute permission to gdb/gdbserver/configure
3003 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
3004 permission. This bug would cause configure to fail on a number of
3005 systems (Solaris, IRIX). Ref: server/519.
3007 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
3009 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
3010 has been updated to use constant array sizes.
3012 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
3014 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
3015 its generated DWARF Call Frame Info. This encoding was causing GDB to
3016 panic, that panic has been fixed. Ref: gdb/1628.
3018 * Fixed a problem when examining parameters in shared library code.
3020 When examining parameters in optimized shared library code generated
3021 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3022 not available''. GDB now correctly displays the variable's value.
3024 *** Changes in GDB 6.1:
3026 * Removed --with-mmalloc
3028 Support for the mmalloc memory manager has been removed, as it
3029 conflicted with the internal gdb byte cache.
3031 * Changes in AMD64 configurations
3033 The AMD64 target now includes the %cs and %ss registers. As a result
3034 the AMD64 remote protocol has changed; this affects the floating-point
3035 and SSE registers. If you rely on those registers for your debugging,
3036 you should upgrade gdbserver on the remote side.
3038 * Revised SPARC target
3040 The SPARC target has been completely revised, incorporating the
3041 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3042 support for LynxOS and SunOS 4 has been dropped. Calling functions
3043 from within GDB on operating systems with a non-executable stack
3044 (Solaris, OpenBSD) now works.
3048 GDB has a new C++ demangler which does a better job on the mangled
3049 names generated by current versions of g++. It also runs faster, so
3050 with this and other changes gdb should now start faster on large C++
3053 * DWARF 2 Location Expressions
3055 GDB support for location expressions has been extended to support function
3056 arguments and frame bases. Older versions of GDB could crash when they
3059 * C++ nested types and namespaces
3061 GDB's support for nested types and namespaces in C++ has been
3062 improved, especially if you use the DWARF 2 debugging format. (This
3063 is the default for recent versions of GCC on most platforms.)
3064 Specifically, if you have a class "Inner" defined within a class or
3065 namespace "Outer", then GDB realizes that the class's name is
3066 "Outer::Inner", not simply "Inner". This should greatly reduce the
3067 frequency of complaints about not finding RTTI symbols. In addition,
3068 if you are stopped at inside of a function defined within a namespace,
3069 GDB modifies its name lookup accordingly.
3071 * New native configurations
3073 NetBSD/amd64 x86_64-*-netbsd*
3074 OpenBSD/amd64 x86_64-*-openbsd*
3075 OpenBSD/alpha alpha*-*-openbsd*
3076 OpenBSD/sparc sparc-*-openbsd*
3077 OpenBSD/sparc64 sparc64-*-openbsd*
3079 * New debugging protocols
3081 M32R with SDI protocol m32r-*-elf*
3083 * "set prompt-escape-char" command deleted.
3085 The command "set prompt-escape-char" has been deleted. This command,
3086 and its very obscure effet on GDB's prompt, was never documented,
3087 tested, nor mentioned in the NEWS file.
3089 * OBSOLETE configurations and files
3091 Configurations that have been declared obsolete in this release have
3092 been commented out. Unless there is activity to revive these
3093 configurations, the next release of GDB will have their sources
3094 permanently REMOVED.
3096 Sun 3, running SunOS 3 m68*-*-sunos3*
3097 Sun 3, running SunOS 4 m68*-*-sunos4*
3098 Sun 2, running SunOS 3 m68000-*-sunos3*
3099 Sun 2, running SunOS 4 m68000-*-sunos4*
3100 Motorola 680x0 running LynxOS m68*-*-lynxos*
3101 AT&T 3b1/Unix pc m68*-att-*
3102 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3103 decstation mips-dec-* mips-little-*
3104 riscos mips-*-riscos* mips-*-sysv*
3105 sonymips mips-sony-*
3106 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3108 * REMOVED configurations and files
3110 SGI Irix-4.x mips-sgi-irix4 or iris4
3111 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3112 Z8000 simulator z8k-zilog-none or z8ksim
3113 Matsushita MN10200 w/simulator mn10200-*-*
3114 H8/500 simulator h8500-hitachi-hms or h8500hms
3115 HP/PA running BSD hppa*-*-bsd*
3116 HP/PA running OSF/1 hppa*-*-osf*
3117 HP/PA Pro target hppa*-*-pro*
3118 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3119 386BSD i[3456]86-*-bsd*
3120 Sequent family i[3456]86-sequent-sysv4*
3121 i[3456]86-sequent-sysv*
3122 i[3456]86-sequent-bsd*
3123 SPARC running LynxOS sparc-*-lynxos*
3124 SPARC running SunOS 4 sparc-*-sunos4*
3125 Tsqware Sparclet sparclet-*-*
3126 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3128 *** Changes in GDB 6.0:
3132 Support for debugging the Objective-C programming language has been
3133 integrated into GDB.
3135 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3137 DWARF 2's Call Frame Information makes available compiler generated
3138 information that more exactly describes the program's run-time stack.
3139 By using this information, GDB is able to provide more robust stack
3142 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3143 have been updated to use a new backtrace mechanism which includes
3144 DWARF 2 CFI support.
3148 GDB's remote protocol has been extended to include support for hosted
3149 file I/O (where the remote target uses GDB's file system). See GDB's
3150 remote protocol documentation for details.
3152 * All targets using the new architecture framework.
3154 All of GDB's targets have been updated to use the new internal
3155 architecture framework. The way is now open for future GDB releases
3156 to include cross-architecture native debugging support (i386 on amd64,
3159 * GNU/Linux's Thread Local Storage (TLS)
3161 GDB now includes support for for the GNU/Linux implementation of
3162 per-thread variables.
3164 * GNU/Linux's Native POSIX Thread Library (NPTL)
3166 GDB's thread code has been updated to work with either the new
3167 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3169 * Separate debug info.
3171 GDB, in conjunction with BINUTILS, now supports a mechanism for
3172 automatically loading debug information from a separate file. Instead
3173 of shipping full debug and non-debug versions of system libraries,
3174 system integrators can now instead ship just the stripped libraries
3175 and optional debug files.
3177 * DWARF 2 Location Expressions
3179 DWARF 2 Location Expressions allow the compiler to more completely
3180 describe the location of variables (even in optimized code) to the
3183 GDB now includes preliminary support for location expressions (support
3184 for DW_OP_piece is still missing).
3188 A number of long standing bugs that caused GDB to die while starting a
3189 Java application have been fixed. GDB's Java support is now
3190 considered "useable".
3192 * GNU/Linux support for fork, vfork, and exec.
3194 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3195 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3198 * GDB supports logging output to a file
3200 There are two new commands, "set logging" and "show logging", which can be
3201 used to capture GDB's output to a file.
3203 * The meaning of "detach" has changed for gdbserver
3205 The "detach" command will now resume the application, as documented. To
3206 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3209 * d10v, m68hc11 `regs' command deprecated
3211 The `info registers' command has been updated so that it displays the
3212 registers using a format identical to the old `regs' command.
3216 A new command, "maint set profile on/off", has been added. This command can
3217 be used to enable or disable profiling while running GDB, to profile a
3218 session or a set of commands. In addition there is a new configure switch,
3219 "--enable-profiling", which will cause GDB to be compiled with profiling
3220 data, for more informative profiling results.
3222 * Default MI syntax changed to "mi2".
3224 The default MI (machine interface) syntax, enabled by the command line
3225 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3226 "mi1", can be enabled by specifying the option "-i=mi1".
3228 Support for the original "mi0" syntax (included in GDB 5.0) has been
3231 Fix for gdb/192: removed extraneous space when displaying frame level.
3232 Fix for gdb/672: update changelist is now output in mi list format.
3233 Fix for gdb/702: a -var-assign that updates the value now shows up
3234 in a subsequent -var-update.
3236 * New native configurations.
3238 FreeBSD/amd64 x86_64-*-freebsd*
3240 * Multi-arched targets.
3242 HP/PA HPUX11 hppa*-*-hpux*
3243 Renesas M32R/D w/simulator m32r-*-elf*
3245 * OBSOLETE configurations and files
3247 Configurations that have been declared obsolete in this release have
3248 been commented out. Unless there is activity to revive these
3249 configurations, the next release of GDB will have their sources
3250 permanently REMOVED.
3252 Z8000 simulator z8k-zilog-none or z8ksim
3253 Matsushita MN10200 w/simulator mn10200-*-*
3254 H8/500 simulator h8500-hitachi-hms or h8500hms
3255 HP/PA running BSD hppa*-*-bsd*
3256 HP/PA running OSF/1 hppa*-*-osf*
3257 HP/PA Pro target hppa*-*-pro*
3258 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3259 Sequent family i[3456]86-sequent-sysv4*
3260 i[3456]86-sequent-sysv*
3261 i[3456]86-sequent-bsd*
3262 Tsqware Sparclet sparclet-*-*
3263 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3265 * REMOVED configurations and files
3268 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3269 IBM AIX PS/2 i[3456]86-*-aix
3270 i386 running Mach 3.0 i[3456]86-*-mach3*
3271 i386 running Mach i[3456]86-*-mach*
3272 i386 running OSF/1 i[3456]86-*osf1mk*
3273 HP/Apollo 68k Family m68*-apollo*-sysv*,
3275 m68*-hp-bsd*, m68*-hp-hpux*
3276 Argonaut Risc Chip (ARC) arc-*-*
3277 Mitsubishi D30V d30v-*-*
3278 Fujitsu FR30 fr30-*-elf*
3279 OS/9000 i[34]86-*-os9k
3280 I960 with MON960 i960-*-coff
3282 * MIPS $fp behavior changed
3284 The convenience variable $fp, for the MIPS, now consistently returns
3285 the address of the current frame's base. Previously, depending on the
3286 context, $fp could refer to either $sp or the current frame's base
3287 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3288 The GNU Source-Level Debugger''.
3290 *** Changes in GDB 5.3:
3292 * GNU/Linux shared library multi-threaded performance improved.
3294 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3295 `/proc', in preference to `ptrace' for memory reads. This may result
3296 in an improvement in the start-up time of multi-threaded, shared
3297 library applications when run under GDB. One GDB user writes: ``loads
3298 shared libs like mad''.
3300 * ``gdbserver'' now supports multi-threaded applications on some targets
3302 Support for debugging multi-threaded applications which use
3303 the GNU/Linux LinuxThreads package has been added for
3304 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3305 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3307 * GDB now supports C/C++ preprocessor macros.
3309 GDB now expands preprocessor macro invocations in C/C++ expressions,
3310 and provides various commands for showing macro definitions and how
3313 The new command `macro expand EXPRESSION' expands any macro
3314 invocations in expression, and shows the result.
3316 The new command `show macro MACRO-NAME' shows the definition of the
3317 macro named MACRO-NAME, and where it was defined.
3319 Most compilers don't include information about macros in the debugging
3320 information by default. In GCC 3.1, for example, you need to compile
3321 your program with the options `-gdwarf-2 -g3'. If the macro
3322 information is present in the executable, GDB will read it.
3324 * Multi-arched targets.
3326 DEC Alpha (partial) alpha*-*-*
3327 DEC VAX (partial) vax-*-*
3329 National Semiconductor NS32000 (partial) ns32k-*-*
3330 Motorola 68000 (partial) m68k-*-*
3331 Motorola MCORE mcore-*-*
3335 Fujitsu FRV architecture added by Red Hat frv*-*-*
3338 * New native configurations
3340 Alpha NetBSD alpha*-*-netbsd*
3341 SH NetBSD sh*-*-netbsdelf*
3342 MIPS NetBSD mips*-*-netbsd*
3343 UltraSPARC NetBSD sparc64-*-netbsd*
3345 * OBSOLETE configurations and files
3347 Configurations that have been declared obsolete in this release have
3348 been commented out. Unless there is activity to revive these
3349 configurations, the next release of GDB will have their sources
3350 permanently REMOVED.
3352 Mitsubishi D30V d30v-*-*
3353 OS/9000 i[34]86-*-os9k
3354 IBM AIX PS/2 i[3456]86-*-aix
3355 Fujitsu FR30 fr30-*-elf*
3356 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3357 Argonaut Risc Chip (ARC) arc-*-*
3358 i386 running Mach 3.0 i[3456]86-*-mach3*
3359 i386 running Mach i[3456]86-*-mach*
3360 i386 running OSF/1 i[3456]86-*osf1mk*
3361 HP/Apollo 68k Family m68*-apollo*-sysv*,
3363 m68*-hp-bsd*, m68*-hp-hpux*
3364 I960 with MON960 i960-*-coff
3366 * OBSOLETE languages
3368 CHILL, a Pascal like language used by telecommunications companies.
3370 * REMOVED configurations and files
3372 AMD 29k family via UDI a29k-amd-udi, udi29k
3373 A29K VxWorks a29k-*-vxworks
3374 AMD 29000 embedded, using EBMON a29k-none-none
3375 AMD 29000 embedded with COFF a29k-none-coff
3376 AMD 29000 embedded with a.out a29k-none-aout
3378 testsuite/gdb.hp/gdb.threads-hp/ directory
3380 * New command "set max-user-call-depth <nnn>"
3382 This command allows the user to limit the call depth of user-defined
3383 commands. The default is 1024.
3385 * Changes in FreeBSD/i386 native debugging.
3387 Support for the "generate-core-file" has been added.
3389 * New commands "dump", "append", and "restore".
3391 These commands allow data to be copied from target memory
3392 to a bfd-format or binary file (dump and append), and back
3393 from a file into memory (restore).
3395 * Improved "next/step" support on multi-processor Alpha Tru64.
3397 The previous single-step mechanism could cause unpredictable problems,
3398 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3399 of a software single-step mechanism prevents this.
3401 *** Changes in GDB 5.2.1:
3409 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3410 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3411 Fix, by Joel Brobecker imported from mainline.
3413 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3414 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3415 Fix, by Fred Fish, imported from mainline.
3417 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3418 Surprisingly enough, it works now.
3419 By Michal Ludvig, imported from mainline.
3421 i386 hardware watchpoint support:
3422 avoid misses on second run for some targets.
3423 By Pierre Muller, imported from mainline.
3425 *** Changes in GDB 5.2:
3427 * New command "set trust-readonly-sections on[off]".
3429 This command is a hint that tells gdb that read-only sections
3430 really are read-only (ie. that their contents will not change).
3431 In this mode, gdb will go to the object file rather than the
3432 target to read memory from read-only sections (such as ".text").
3433 This can be a significant performance improvement on some
3434 (notably embedded) targets.
3436 * New command "generate-core-file" (or "gcore").
3438 This new gdb command allows the user to drop a core file of the child
3439 process state at any time. So far it's been implemented only for
3440 GNU/Linux and Solaris, but should be relatively easily ported to other
3441 hosts. Argument is core file name (defaults to core.<pid>).
3443 * New command line option
3445 GDB now accepts --pid or -p followed by a process id.
3447 * Change in command line behavior -- corefiles vs. process ids.
3449 There is a subtle behavior in the way in which GDB handles
3450 command line arguments. The first non-flag argument is always
3451 a program to debug, but the second non-flag argument may either
3452 be a corefile or a process id. Previously, GDB would attempt to
3453 open the second argument as a corefile, and if that failed, would
3454 issue a superfluous error message and then attempt to attach it as
3455 a process. Now, if the second argument begins with a non-digit,
3456 it will be treated as a corefile. If it begins with a digit,
3457 GDB will attempt to attach it as a process, and if no such process
3458 is found, will then attempt to open it as a corefile.
3460 * Changes in ARM configurations.
3462 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3463 configuration is fully multi-arch.
3465 * New native configurations
3467 ARM NetBSD arm*-*-netbsd*
3468 x86 OpenBSD i[3456]86-*-openbsd*
3469 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3470 Sparc64 running FreeBSD sparc64-*-freebsd*
3474 Sanyo XStormy16 xstormy16-elf
3476 * OBSOLETE configurations and files
3478 Configurations that have been declared obsolete in this release have
3479 been commented out. Unless there is activity to revive these
3480 configurations, the next release of GDB will have their sources
3481 permanently REMOVED.
3483 AMD 29k family via UDI a29k-amd-udi, udi29k
3484 A29K VxWorks a29k-*-vxworks
3485 AMD 29000 embedded, using EBMON a29k-none-none
3486 AMD 29000 embedded with COFF a29k-none-coff
3487 AMD 29000 embedded with a.out a29k-none-aout
3489 testsuite/gdb.hp/gdb.threads-hp/ directory
3491 * REMOVED configurations and files
3493 TI TMS320C80 tic80-*-*
3495 PowerPC Solaris powerpcle-*-solaris*
3496 PowerPC Windows NT powerpcle-*-cygwin32
3497 PowerPC Netware powerpc-*-netware*
3498 Harris/CXUX m88k m88*-harris-cxux*
3499 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3500 ns32k-utek-sysv* ns32k-utek-*
3501 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3502 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3503 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3504 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3505 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3507 * Changes to command line processing
3509 The new `--args' feature can be used to specify command-line arguments
3510 for the inferior from gdb's command line.
3512 * Changes to key bindings
3514 There is a new `operate-and-get-next' function bound to `C-o'.
3516 *** Changes in GDB 5.1.1
3518 Fix compile problem on DJGPP.
3520 Fix a problem with floating-point registers on the i386 being
3523 Fix to stop GDB crashing on .debug_str debug info.
3525 Numerous documentation fixes.
3527 Numerous testsuite fixes.
3529 *** Changes in GDB 5.1:
3531 * New native configurations
3533 Alpha FreeBSD alpha*-*-freebsd*
3534 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3535 MIPS GNU/Linux mips*-*-linux*
3536 MIPS SGI Irix 6.x mips*-sgi-irix6*
3537 ia64 AIX ia64-*-aix*
3538 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3542 Motorola 68HC11 and 68HC12 m68hc11-elf
3544 UltraSparc running GNU/Linux sparc64-*-linux*
3546 * OBSOLETE configurations and files
3548 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3549 Harris/CXUX m88k m88*-harris-cxux*
3550 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3551 ns32k-utek-sysv* ns32k-utek-*
3552 TI TMS320C80 tic80-*-*
3554 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3555 PowerPC Solaris powerpcle-*-solaris*
3556 PowerPC Windows NT powerpcle-*-cygwin32
3557 PowerPC Netware powerpc-*-netware*
3558 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3559 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3560 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3561 Apple Macintosh (MPW) host N/A
3563 stuff.c (Program to stuff files into a specially prepared space in kdb)
3564 kdb-start.c (Main loop for the standalone kernel debugger)
3566 Configurations that have been declared obsolete in this release have
3567 been commented out. Unless there is activity to revive these
3568 configurations, the next release of GDB will have their sources
3569 permanently REMOVED.
3571 * REMOVED configurations and files
3573 Altos 3068 m68*-altos-*
3574 Convex c1-*-*, c2-*-*
3576 ARM RISCix arm-*-* (as host)
3580 * GDB has been converted to ISO C.
3582 GDB's source code has been converted to ISO C. In particular, the
3583 sources are fully protoized, and rely on standard headers being
3588 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3590 * The MI enabled by default.
3592 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3593 revised and enabled by default. Packages which use GDB as a debugging
3594 engine behind a UI or another front end are encouraged to switch to
3595 using the GDB/MI interface, instead of the old annotations interface
3596 which is now deprecated.
3598 * Support for debugging Pascal programs.
3600 GDB now includes support for debugging Pascal programs. The following
3601 main features are supported:
3603 - Pascal-specific data types such as sets;
3605 - automatic recognition of Pascal sources based on file-name
3608 - Pascal-style display of data types, variables, and functions;
3610 - a Pascal expression parser.
3612 However, some important features are not yet supported.
3614 - Pascal string operations are not supported at all;
3616 - there are some problems with boolean types;
3618 - Pascal type hexadecimal constants are not supported
3619 because they conflict with the internal variables format;
3621 - support for Pascal objects and classes is not full yet;
3623 - unlike Pascal, GDB is case-sensitive for symbol names.
3625 * Changes in completion.
3627 Commands such as `shell', `run' and `set args', which pass arguments
3628 to inferior programs, now complete on file names, similar to what
3629 users expect at the shell prompt.
3631 Commands which accept locations, such as `disassemble', `print',
3632 `breakpoint', `until', etc. now complete on filenames as well as
3633 program symbols. Thus, if you type "break foob TAB", and the source
3634 files linked into the programs include `foobar.c', that file name will
3635 be one of the candidates for completion. However, file names are not
3636 considered for completion after you typed a colon that delimits a file
3637 name from a name of a function in that file, as in "break foo.c:bar".
3639 `set demangle-style' completes on available demangling styles.
3641 * New platform-independent commands:
3643 It is now possible to define a post-hook for a command as well as a
3644 hook that runs before the command. For more details, see the
3645 documentation of `hookpost' in the GDB manual.
3647 * Changes in GNU/Linux native debugging.
3649 Support for debugging multi-threaded programs has been completely
3650 revised for all platforms except m68k and sparc. You can now debug as
3651 many threads as your system allows you to have.
3653 Attach/detach is supported for multi-threaded programs.
3655 Support for SSE registers was added for x86. This doesn't work for
3656 multi-threaded programs though.
3658 * Changes in MIPS configurations.
3660 Multi-arch support is enabled for all MIPS configurations.
3662 GDB can now be built as native debugger on SGI Irix 6.x systems for
3663 debugging n32 executables. (Debugging 64-bit executables is not yet
3666 * Unified support for hardware watchpoints in all x86 configurations.
3668 Most (if not all) native x86 configurations support hardware-assisted
3669 breakpoints and watchpoints in a unified manner. This support
3670 implements debug register sharing between watchpoints, which allows to
3671 put a virtually infinite number of watchpoints on the same address,
3672 and also supports watching regions up to 16 bytes with several debug
3675 The new maintenance command `maintenance show-debug-regs' toggles
3676 debugging print-outs in functions that insert, remove, and test
3677 watchpoints and hardware breakpoints.
3679 * Changes in the DJGPP native configuration.
3681 New command ``info dos sysinfo'' displays assorted information about
3682 the CPU, OS, memory, and DPMI server.
3684 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3685 display information about segment descriptors stored in GDT, LDT, and
3688 New commands ``info dos pde'' and ``info dos pte'' display entries
3689 from Page Directory and Page Tables (for now works with CWSDPMI only).
3690 New command ``info dos address-pte'' displays the Page Table entry for
3691 a given linear address.
3693 GDB can now pass command lines longer than 126 characters to the
3694 program being debugged (requires an update to the libdbg.a library
3695 which is part of the DJGPP development kit).
3697 DWARF2 debug info is now supported.
3699 It is now possible to `step' and `next' through calls to `longjmp'.
3701 * Changes in documentation.
3703 All GDB documentation was converted to GFDL, the GNU Free
3704 Documentation License.
3706 Tracepoints-related commands are now fully documented in the GDB
3709 TUI, the Text-mode User Interface, is now documented in the manual.
3711 Tracepoints-related commands are now fully documented in the GDB
3714 The "GDB Internals" manual now has an index. It also includes
3715 documentation of `ui_out' functions, GDB coding standards, x86
3716 hardware watchpoints, and memory region attributes.
3718 * GDB's version number moved to ``version.in''
3720 The Makefile variable VERSION has been replaced by the file
3721 ``version.in''. People creating GDB distributions should update the
3722 contents of this file.
3726 GUD support is now a standard part of the EMACS distribution.
3728 *** Changes in GDB 5.0:
3730 * Improved support for debugging FP programs on x86 targets
3732 Unified and much-improved support for debugging floating-point
3733 programs on all x86 targets. In particular, ``info float'' now
3734 displays the FP registers in the same format on all x86 targets, with
3735 greater level of detail.
3737 * Improvements and bugfixes in hardware-assisted watchpoints
3739 It is now possible to watch array elements, struct members, and
3740 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3741 on x86 targets no longer erroneously trigger when the address is
3744 * Improvements in the native DJGPP version of GDB
3746 The distribution now includes all the scripts and auxiliary files
3747 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3748 machines ``out of the box''.
3750 The DJGPP version can now debug programs that use signals. It is
3751 possible to catch signals that happened in the debuggee, deliver
3752 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3753 would kill the program being debugged.) Programs that hook hardware
3754 interrupts (keyboard, timer, etc.) can also be debugged.
3756 It is now possible to debug DJGPP programs that redirect their
3757 standard handles or switch them to raw (as opposed to cooked) mode, or
3758 even close them. The command ``run < foo > bar'' works as expected,
3759 and ``info terminal'' reports useful information about the debuggee's
3760 terminal, including raw/cooked mode, redirection, etc.
3762 The DJGPP version now uses termios functions for console I/O, which
3763 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3766 DOS-style file names with drive letters are now fully supported by
3769 It is now possible to debug DJGPP programs that switch their working
3770 directory. It is also possible to rerun the debuggee any number of
3771 times without restarting GDB; thus, you can use the same setup,
3772 breakpoints, etc. for many debugging sessions.
3774 * New native configurations
3776 ARM GNU/Linux arm*-*-linux*
3777 PowerPC GNU/Linux powerpc-*-linux*
3781 Motorola MCore mcore-*-*
3782 x86 VxWorks i[3456]86-*-vxworks*
3783 PowerPC VxWorks powerpc-*-vxworks*
3784 TI TMS320C80 tic80-*-*
3786 * OBSOLETE configurations
3788 Altos 3068 m68*-altos-*
3789 Convex c1-*-*, c2-*-*
3791 ARM RISCix arm-*-* (as host)
3794 Configurations that have been declared obsolete will be commented out,
3795 but the code will be left in place. If there is no activity to revive
3796 these configurations before the next release of GDB, the sources will
3797 be permanently REMOVED.
3799 * Gould support removed
3801 Support for the Gould PowerNode and NP1 has been removed.
3803 * New features for SVR4
3805 On SVR4 native platforms (such as Solaris), if you attach to a process
3806 without first loading a symbol file, GDB will now attempt to locate and
3807 load symbols from the running process's executable file.
3809 * Many C++ enhancements
3811 C++ support has been greatly improved. Overload resolution now works properly
3812 in almost all cases. RTTI support is on the way.
3814 * Remote targets can connect to a sub-program
3816 A popen(3) style serial-device has been added. This device starts a
3817 sub-process (such as a stand-alone simulator) and then communicates
3818 with that. The sub-program to run is specified using the syntax
3819 ``|<program> <args>'' vis:
3821 (gdb) set remotedebug 1
3822 (gdb) target extended-remote |mn10300-elf-sim program-args
3824 * MIPS 64 remote protocol
3826 A long standing bug in the mips64 remote protocol where by GDB
3827 expected certain 32 bit registers (ex SR) to be transfered as 32
3828 instead of 64 bits has been fixed.
3830 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3831 added to provide backward compatibility with older versions of GDB.
3833 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3835 The command ``set remotebinarydownload'' command has been replaced by
3836 ``set remote X-packet''. Other commands in ``set remote'' family
3837 include ``set remote P-packet''.
3839 * Breakpoint commands accept ranges.
3841 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3842 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3843 ``tracepoint passcount'' also accepts a range of tracepoints.
3845 * ``apropos'' command added.
3847 The ``apropos'' command searches through command names and
3848 documentation strings, printing out matches, making it much easier to
3849 try to find a command that does what you are looking for.
3853 A new machine oriented interface (MI) has been added to GDB. This
3854 interface is designed for debug environments running GDB as a separate
3855 process. This is part of the long term libGDB project. See the
3856 "GDB/MI" chapter of the GDB manual for further information. It can be
3857 enabled by configuring with:
3859 .../configure --enable-gdbmi
3861 *** Changes in GDB-4.18:
3863 * New native configurations
3865 HP-UX 10.20 hppa*-*-hpux10.20
3866 HP-UX 11.x hppa*-*-hpux11.0*
3867 M68K GNU/Linux m68*-*-linux*
3871 Fujitsu FR30 fr30-*-elf*
3872 Intel StrongARM strongarm-*-*
3873 Mitsubishi D30V d30v-*-*
3875 * OBSOLETE configurations
3877 Gould PowerNode, NP1 np1-*-*, pn-*-*
3879 Configurations that have been declared obsolete will be commented out,
3880 but the code will be left in place. If there is no activity to revive
3881 these configurations before the next release of GDB, the sources will
3882 be permanently REMOVED.
3886 As a compatibility experiment, GDB's source files buildsym.h and
3887 buildsym.c have been converted to pure standard C, no longer
3888 containing any K&R compatibility code. We believe that all systems in
3889 use today either come with a standard C compiler, or have a GCC port
3890 available. If this is not true, please report the affected
3891 configuration to bug-gdb@gnu.org immediately. See the README file for
3892 information about getting a standard C compiler if you don't have one
3897 GDB now uses readline 2.2.
3899 * set extension-language
3901 You can now control the mapping between filename extensions and source
3902 languages by using the `set extension-language' command. For instance,
3903 you can ask GDB to treat .c files as C++ by saying
3904 set extension-language .c c++
3905 The command `info extensions' lists all of the recognized extensions
3906 and their associated languages.
3908 * Setting processor type for PowerPC and RS/6000
3910 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3911 you can use the `set processor' command to specify what variant of the
3912 PowerPC family you are debugging. The command
3916 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3917 following PowerPC and RS6000 variants:
3919 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3920 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3922 403GC IBM PowerPC 403GC
3923 505 Motorola PowerPC 505
3924 860 Motorola PowerPC 860 or 850
3925 601 Motorola PowerPC 601
3926 602 Motorola PowerPC 602
3927 603 Motorola/IBM PowerPC 603 or 603e
3928 604 Motorola PowerPC 604 or 604e
3929 750 Motorola/IBM PowerPC 750 or 750
3931 At the moment, this command just tells GDB what to name the
3932 special-purpose processor registers. Since almost all the affected
3933 registers are inaccessible to user-level programs, this command is
3934 only useful for remote debugging in its present form.
3938 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3939 more extensive support for HP-UX. Added features include shared
3940 library support, kernel threads and hardware watchpoints for 11.00,
3941 support for HP's ANSI C and C++ compilers, and a compatibility mode
3942 for xdb and dbx commands.
3946 HP's donation includes the new concept of catchpoints, which is a
3947 generalization of the old catch command. On HP-UX, it is now possible
3948 to catch exec, fork, and vfork, as well as library loading.
3950 This means that the existing catch command has changed; its first
3951 argument now specifies the type of catch to be set up. See the
3952 output of "help catch" for a list of catchpoint types.
3954 * Debugging across forks
3956 On HP-UX, you can choose which process to debug when a fork() happens
3961 HP has donated a curses-based terminal user interface (TUI). To get
3962 it, build with --enable-tui. Although this can be enabled for any
3963 configuration, at present it only works for native HP debugging.
3965 * GDB remote protocol additions
3967 A new protocol packet 'X' that writes binary data is now available.
3968 Default behavior is to try 'X', then drop back to 'M' if the stub
3969 fails to respond. The settable variable `remotebinarydownload'
3970 allows explicit control over the use of 'X'.
3972 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3973 full 64-bit address. The command
3975 set remoteaddresssize 32
3977 can be used to revert to the old behaviour. For existing remote stubs
3978 the change should not be noticed, as the additional address information
3981 In order to assist in debugging stubs, you may use the maintenance
3982 command `packet' to send any text string to the stub. For instance,
3984 maint packet heythere
3986 sends the packet "$heythere#<checksum>". Note that it is very easy to
3987 disrupt a debugging session by sending the wrong packet at the wrong
3990 The compare-sections command allows you to compare section data on the
3991 target to what is in the executable file without uploading or
3992 downloading, by comparing CRC checksums.
3994 * Tracing can collect general expressions
3996 You may now collect general expressions at tracepoints. This requires
3997 further additions to the target-side stub; see tracepoint.c and
3998 doc/agentexpr.texi for further details.
4000 * mask-address variable for Mips
4002 For Mips targets, you may control the zeroing of the upper 32 bits of
4003 a 64-bit address by entering `set mask-address on'. This is mainly
4004 of interest to users of embedded R4xxx and R5xxx processors.
4006 * Higher serial baud rates
4008 GDB's serial code now allows you to specify baud rates 57600, 115200,
4009 230400, and 460800 baud. (Note that your host system may not be able
4010 to achieve all of these rates.)
4014 The i960 configuration now includes an initial implementation of a
4015 builtin simulator, contributed by Jim Wilson.
4018 *** Changes in GDB-4.17:
4020 * New native configurations
4022 Alpha GNU/Linux alpha*-*-linux*
4023 Unixware 2.x i[3456]86-unixware2*
4024 Irix 6.x mips*-sgi-irix6*
4025 PowerPC GNU/Linux powerpc-*-linux*
4026 PowerPC Solaris powerpcle-*-solaris*
4027 Sparc GNU/Linux sparc-*-linux*
4028 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4032 Argonaut Risc Chip (ARC) arc-*-*
4033 Hitachi H8/300S h8300*-*-*
4034 Matsushita MN10200 w/simulator mn10200-*-*
4035 Matsushita MN10300 w/simulator mn10300-*-*
4036 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4037 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4038 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4039 Mitsubishi D10V w/simulator d10v-*-*
4040 Mitsubishi M32R/D w/simulator m32r-*-elf*
4041 Tsqware Sparclet sparclet-*-*
4042 NEC V850 w/simulator v850-*-*
4044 * New debugging protocols
4046 ARM with RDI protocol arm*-*-*
4047 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4048 DDB and LSI variants of PMON protocol mips*-*-*
4049 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4050 PowerPC with SDS protocol powerpc{,le}-*-eabi
4051 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4055 All configurations can now understand and use the DWARF 2 debugging
4056 format. The choice is automatic, if the symbol file contains DWARF 2
4061 GDB now includes basic Java language support. This support is
4062 only useful with Java compilers that produce native machine code.
4064 * solib-absolute-prefix and solib-search-path
4066 For SunOS and SVR4 shared libraries, you may now set the prefix for
4067 loading absolute shared library symbol files, and the search path for
4068 locating non-absolute shared library symbol files.
4070 * Live range splitting
4072 GDB can now effectively debug code for which GCC has performed live
4073 range splitting as part of its optimization. See gdb/doc/LRS for
4074 more details on the expected format of the stabs information.
4078 GDB's support for the GNU Hurd, including thread debugging, has been
4079 updated to work with current versions of the Hurd.
4083 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4084 instruction set. ARM GDB automatically detects when Thumb
4085 instructions are in use, and adjusts disassembly and backtracing
4090 GDB's MIPS target configurations now handle the MIP16 16-bit
4095 GDB now includes support for overlays; if an executable has been
4096 linked such that multiple sections are based at the same address, GDB
4097 will decide which section to use for symbolic info. You can choose to
4098 control the decision manually, using overlay commands, or implement
4099 additional target-side support and use "overlay load-target" to bring
4100 in the overlay mapping. Do "help overlay" for more detail.
4104 The command "info symbol <address>" displays information about
4105 the symbol at the specified address.
4109 The standard remote protocol now includes an extension that allows
4110 asynchronous collection and display of trace data. This requires
4111 extensive support in the target-side debugging stub. Tracing mode
4112 includes a new interaction mode in GDB and new commands: see the
4113 file tracepoint.c for more details.
4117 Configurations for embedded MIPS now include a simulator contributed
4118 by Cygnus Solutions. The simulator supports the instruction sets
4119 of most MIPS variants.
4123 Sparc configurations may now include the ERC32 simulator contributed
4124 by the European Space Agency. The simulator is not built into
4125 Sparc targets by default; configure with --enable-sim to include it.
4129 For target configurations that may include multiple variants of a
4130 basic architecture (such as MIPS and SH), you may now set the
4131 architecture explicitly. "set arch" sets, "info arch" lists
4132 the possible architectures.
4134 *** Changes in GDB-4.16:
4136 * New native configurations
4138 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4139 M68K NetBSD m68k-*-netbsd*
4140 PowerPC AIX 4.x powerpc-*-aix*
4141 PowerPC MacOS powerpc-*-macos*
4142 PowerPC Windows NT powerpcle-*-cygwin32
4143 RS/6000 AIX 4.x rs6000-*-aix4*
4147 ARM with RDP protocol arm-*-*
4148 I960 with MON960 i960-*-coff
4149 MIPS VxWorks mips*-*-vxworks*
4150 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4151 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4153 Matra Sparclet sparclet-*-*
4157 The powerpc-eabi configuration now includes the PSIM simulator,
4158 contributed by Andrew Cagney, with assistance from Mike Meissner.
4159 PSIM is a very elaborate model of the PowerPC, including not only
4160 basic instruction set execution, but also details of execution unit
4161 performance and I/O hardware. See sim/ppc/README for more details.
4165 GDB now works with Solaris 2.5.
4167 * Windows 95/NT native
4169 GDB will now work as a native debugger on Windows 95 and Windows NT.
4170 To build it from source, you must use the "gnu-win32" environment,
4171 which uses a DLL to emulate enough of Unix to run the GNU tools.
4172 Further information, binaries, and sources are available at
4173 ftp.cygnus.com, under pub/gnu-win32.
4175 * dont-repeat command
4177 If a user-defined command includes the command `dont-repeat', then the
4178 command will not be repeated if the user just types return. This is
4179 useful if the command is time-consuming to run, so that accidental
4180 extra keystrokes don't run the same command many times.
4182 * Send break instead of ^C
4184 The standard remote protocol now includes an option to send a break
4185 rather than a ^C to the target in order to interrupt it. By default,
4186 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4188 * Remote protocol timeout
4190 The standard remote protocol includes a new variable `remotetimeout'
4191 that allows you to set the number of seconds before GDB gives up trying
4192 to read from the target. The default value is 2.
4194 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4196 By default GDB will automatically keep track of objects as they are
4197 loaded and unloaded by the dynamic linker. By using the command `set
4198 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4199 when shared library events occur, thus allowing you to set breakpoints
4200 in shared libraries which are explicitly loaded by the inferior.
4202 Note this feature does not work on hpux8. On hpux9 you must link
4203 /usr/lib/end.o into your program. This feature should work
4204 automatically on hpux10.
4206 * Irix 5.x hardware watchpoint support
4208 Irix 5 configurations now support the use of hardware watchpoints.
4210 * Mips protocol "SYN garbage limit"
4212 When debugging a Mips target using the `target mips' protocol, you
4213 may set the number of characters that GDB will ignore by setting
4214 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4215 every character. The default value is 1050.
4217 * Recording and replaying remote debug sessions
4219 If you set `remotelogfile' to the name of a file, gdb will write to it
4220 a recording of a remote debug session. This recording may then be
4221 replayed back to gdb using "gdbreplay". See gdbserver/README for
4222 details. This is useful when you have a problem with GDB while doing
4223 remote debugging; you can make a recording of the session and send it
4224 to someone else, who can then recreate the problem.
4226 * Speedups for remote debugging
4228 GDB includes speedups for downloading and stepping MIPS systems using
4229 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4230 and more efficient S-record downloading.
4232 * Memory use reductions and statistics collection
4234 GDB now uses less memory and reports statistics about memory usage.
4235 Try the `maint print statistics' command, for example.
4237 *** Changes in GDB-4.15:
4239 * Psymtabs for XCOFF
4241 The symbol reader for AIX GDB now uses partial symbol tables. This
4242 can greatly improve startup time, especially for large executables.
4244 * Remote targets use caching
4246 Remote targets now use a data cache to speed up communication with the
4247 remote side. The data cache could lead to incorrect results because
4248 it doesn't know about volatile variables, thus making it impossible to
4249 debug targets which use memory mapped I/O devices. `set remotecache
4250 off' turns the the data cache off.
4252 * Remote targets may have threads
4254 The standard remote protocol now includes support for multiple threads
4255 in the target system, using new protocol commands 'H' and 'T'. See
4256 gdb/remote.c for details.
4260 If GDB is configured with `--enable-netrom', then it will include
4261 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4262 acts as though it is a bank of ROM on the target board, but you can
4263 write into it over the network. GDB's support consists only of
4264 support for fast loading into the emulated ROM; to debug, you must use
4265 another protocol, such as standard remote protocol. The usual
4266 sequence is something like
4268 target nrom <netrom-hostname>
4270 target remote <netrom-hostname>:1235
4274 GDB now includes support for the Apple Macintosh, as a host only. It
4275 may be run as either an MPW tool or as a standalone application, and
4276 it can debug through the serial port. All the usual GDB commands are
4277 available, but to the target command, you must supply "serial" as the
4278 device type instead of "/dev/ttyXX". See mpw-README in the main
4279 directory for more information on how to build. The MPW configuration
4280 scripts */mpw-config.in support only a few targets, and only the
4281 mips-idt-ecoff target has been tested.
4285 GDB configuration now uses autoconf. This is not user-visible,
4286 but does simplify configuration and building.
4290 GDB now supports hpux10.
4292 *** Changes in GDB-4.14:
4294 * New native configurations
4296 x86 FreeBSD i[345]86-*-freebsd
4297 x86 NetBSD i[345]86-*-netbsd
4298 NS32k NetBSD ns32k-*-netbsd
4299 Sparc NetBSD sparc-*-netbsd
4303 A29K VxWorks a29k-*-vxworks
4304 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4305 CPU32 EST-300 emulator m68*-*-est*
4306 PowerPC ELF powerpc-*-elf
4309 * Alpha OSF/1 support for procfs
4311 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4312 possible to attach to running processes. As the mounting of the /proc
4313 filesystem is optional on the Alpha, GDB automatically determines
4314 the availability of /proc during startup. This can lead to problems
4315 if /proc is unmounted after GDB has been started.
4317 * Arguments to user-defined commands
4319 User commands may accept up to 10 arguments separated by whitespace.
4320 Arguments are accessed within the user command via $arg0..$arg9. A
4323 print $arg0 + $arg1 + $arg2
4325 To execute the command use:
4328 Defines the command "adder" which prints the sum of its three arguments.
4329 Note the arguments are text substitutions, so they may reference variables,
4330 use complex expressions, or even perform inferior function calls.
4332 * New `if' and `while' commands
4334 This makes it possible to write more sophisticated user-defined
4335 commands. Both commands take a single argument, which is the
4336 expression to evaluate, and must be followed by the commands to
4337 execute, one per line, if the expression is nonzero, the list being
4338 terminated by the word `end'. The `if' command list may include an
4339 `else' word, which causes the following commands to be executed only
4340 if the expression is zero.
4342 * Fortran source language mode
4344 GDB now includes partial support for Fortran 77. It will recognize
4345 Fortran programs and can evaluate a subset of Fortran expressions, but
4346 variables and functions may not be handled correctly. GDB will work
4347 with G77, but does not yet know much about symbols emitted by other
4350 * Better HPUX support
4352 Most debugging facilities now work on dynamic executables for HPPAs
4353 running hpux9 or later. You can attach to running dynamically linked
4354 processes, but by default the dynamic libraries will be read-only, so
4355 for instance you won't be able to put breakpoints in them. To change
4356 that behavior do the following before running the program:
4362 This will cause the libraries to be mapped private and read-write.
4363 To revert to the normal behavior, do this:
4369 You cannot set breakpoints or examine data in the library until after
4370 the library is loaded if the function/data symbols do not have
4373 GDB can now also read debug symbols produced by the HP C compiler on
4374 HPPAs (sorry, no C++, Fortran or 68k support).
4376 * Target byte order now dynamically selectable
4378 You can choose which byte order to use with a target system, via the
4379 commands "set endian big" and "set endian little", and you can see the
4380 current setting by using "show endian". You can also give the command
4381 "set endian auto", in which case GDB will use the byte order
4382 associated with the executable. Currently, only embedded MIPS
4383 configurations support dynamic selection of target byte order.
4385 * New DOS host serial code
4387 This version uses DPMI interrupts to handle buffered I/O, so you
4388 no longer need to run asynctsr when debugging boards connected to
4391 *** Changes in GDB-4.13:
4393 * New "complete" command
4395 This lists all the possible completions for the rest of the line, if it
4396 were to be given as a command itself. This is intended for use by emacs.
4398 * Trailing space optional in prompt
4400 "set prompt" no longer adds a space for you after the prompt you set. This
4401 allows you to set a prompt which ends in a space or one that does not.
4403 * Breakpoint hit counts
4405 "info break" now displays a count of the number of times the breakpoint
4406 has been hit. This is especially useful in conjunction with "ignore"; you
4407 can ignore a large number of breakpoint hits, look at the breakpoint info
4408 to see how many times the breakpoint was hit, then run again, ignoring one
4409 less than that number, and this will get you quickly to the last hit of
4412 * Ability to stop printing at NULL character
4414 "set print null-stop" will cause GDB to stop printing the characters of
4415 an array when the first NULL is encountered. This is useful when large
4416 arrays actually contain only short strings.
4418 * Shared library breakpoints
4420 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4421 breakpoints in shared libraries before the executable is run.
4423 * Hardware watchpoints
4425 There is a new hardware breakpoint for the watch command for sparclite
4426 targets. See gdb/sparclite/hw_breakpoint.note.
4428 Hardware watchpoints are also now supported under GNU/Linux.
4432 Annotations have been added. These are for use with graphical interfaces,
4433 and are still experimental. Currently only gdba.el uses these.
4435 * Improved Irix 5 support
4437 GDB now works properly with Irix 5.2.
4439 * Improved HPPA support
4441 GDB now works properly with the latest GCC and GAS.
4443 * New native configurations
4445 Sequent PTX4 i[34]86-sequent-ptx4
4446 HPPA running OSF/1 hppa*-*-osf*
4447 Atari TT running SVR4 m68*-*-sysv4*
4448 RS/6000 LynxOS rs6000-*-lynxos*
4452 OS/9000 i[34]86-*-os9k
4453 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4456 * Hitachi SH7000 and E7000-PC ICE support
4458 There is now support for communicating with the Hitachi E7000-PC ICE.
4459 This is available automatically when GDB is configured for the SH.
4463 As usual, a variety of small fixes and improvements, both generic
4464 and configuration-specific. See the ChangeLog for more detail.
4466 *** Changes in GDB-4.12:
4468 * Irix 5 is now supported
4472 GDB-4.12 on the HPPA has a number of changes which make it unable
4473 to debug the output from the currently released versions of GCC and
4474 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4475 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4476 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4479 *** Changes in GDB-4.11:
4481 * User visible changes:
4485 The "set remotedebug" option is now consistent between the mips remote
4486 target, remote targets using the gdb-specific protocol, UDI (AMD's
4487 debug protocol for the 29k) and the 88k bug monitor. It is now an
4488 integer specifying a debug level (normally 0 or 1, but 2 means more
4489 debugging info for the mips target).
4491 * DEC Alpha native support
4493 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4494 debug info, but GDB works fairly well with the DEC compiler and should
4495 work with a future GCC release. See the README file for a few
4496 Alpha-specific notes.
4498 * Preliminary thread implementation
4500 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4502 * LynxOS native and target support for 386
4504 This release has been hosted on LynxOS 2.2, and also can be configured
4505 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4508 * Improvements in C++ mangling/demangling.
4510 This release has much better g++ debugging, specifically in name
4511 mangling/demangling, virtual function calls, print virtual table,
4512 call methods, ...etc.
4514 *** Changes in GDB-4.10:
4516 * User visible changes:
4518 Remote debugging using the GDB-specific (`target remote') protocol now
4519 supports the `load' command. This is only useful if you have some
4520 other way of getting the stub to the target system, and you can put it
4521 somewhere in memory where it won't get clobbered by the download.
4523 Filename completion now works.
4525 When run under emacs mode, the "info line" command now causes the
4526 arrow to point to the line specified. Also, "info line" prints
4527 addresses in symbolic form (as well as hex).
4529 All vxworks based targets now support a user settable option, called
4530 vxworks-timeout. This option represents the number of seconds gdb
4531 should wait for responses to rpc's. You might want to use this if
4532 your vxworks target is, perhaps, a slow software simulator or happens
4533 to be on the far side of a thin network line.
4537 This release contains support for using a DEC alpha as a GDB host for
4538 cross debugging. Native alpha debugging is not supported yet.
4541 *** Changes in GDB-4.9:
4545 This is the first GDB release which is accompanied by a matching testsuite.
4546 The testsuite requires installation of dejagnu, which should be available
4547 via ftp from most sites that carry GNU software.
4551 'Cfront' style demangling has had its name changed to 'ARM' style, to
4552 emphasize that it was written from the specifications in the C++ Annotated
4553 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4554 disclaimers, it still generated too much confusion with users attempting to
4555 use gdb with AT&T cfront.
4559 GDB now uses a standard remote interface to a simulator library.
4560 So far, the library contains simulators for the Zilog Z8001/2, the
4561 Hitachi H8/300, H8/500 and Super-H.
4563 * New targets supported
4565 H8/300 simulator h8300-hitachi-hms or h8300hms
4566 H8/500 simulator h8500-hitachi-hms or h8500hms
4567 SH simulator sh-hitachi-hms or sh
4568 Z8000 simulator z8k-zilog-none or z8ksim
4569 IDT MIPS board over serial line mips-idt-ecoff
4571 Cross-debugging to GO32 targets is supported. It requires a custom
4572 version of the i386-stub.c module which is integrated with the
4573 GO32 memory extender.
4575 * New remote protocols
4577 MIPS remote debugging protocol.
4579 * New source languages supported
4581 This version includes preliminary support for Chill, a Pascal like language
4582 used by telecommunications companies. Chill support is also being integrated
4583 into the GNU compiler, but we don't know when it will be publically available.
4586 *** Changes in GDB-4.8:
4588 * HP Precision Architecture supported
4590 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4591 version of this support was available as a set of patches from the
4592 University of Utah. GDB does not support debugging of programs
4593 compiled with the HP compiler, because HP will not document their file
4594 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4595 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4597 Many problems in the preliminary version have been fixed.
4599 * Faster and better demangling
4601 We have improved template demangling and fixed numerous bugs in the GNU style
4602 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4603 character types (wchar_t) are now supported. Demangling of each symbol is now
4604 only done once, and is cached when the symbol table for a file is read in.
4605 This results in a small increase in memory usage for C programs, a moderate
4606 increase in memory usage for C++ programs, and a fantastic speedup in
4609 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4610 from the specifications in the Annotated Reference Manual, which AT&T's
4611 compiler does not actually implement.
4613 * G++ multiple inheritance compiler problem
4615 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4616 inheritance lattices was reworked to properly discover ambiguities. We
4617 recently found an example which causes this new algorithm to fail in a
4618 very subtle way, producing bad debug information for those classes.
4619 The file 'gcc.patch' (in this directory) can be applied to gcc to
4620 circumvent the problem. A future GCC release will contain a complete
4623 The previous G++ debug info problem (mentioned below for the gdb-4.7
4624 release) is fixed in gcc version 2.3.2.
4626 * Improved configure script
4628 The `configure' script will now attempt to guess your system type if
4629 you don't supply a host system type. The old scheme of supplying a
4630 host system triplet is preferable over using this. All the magic is
4631 done in the new `config.guess' script. Examine it for details.
4633 We have also brought our configure script much more in line with the FSF's
4634 version. It now supports the --with-xxx options. In particular,
4635 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4636 The resulting GDB will not be able to read arbitrary object file formats --
4637 only the format ``expected'' to be used on the configured target system.
4638 We hope to make this the default in a future release.
4640 * Documentation improvements
4642 There's new internal documentation on how to modify GDB, and how to
4643 produce clean changes to the code. We implore people to read it
4644 before submitting changes.
4646 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4647 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4648 `info' files are also provided. To build `info' files from scratch,
4649 you will need the latest `makeinfo' release, which will be available in
4650 a future texinfo-X.Y release.
4652 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4653 We're not sure exactly which versions have this problem, but it has
4654 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4655 or better. If that isn't possible, there is a patch in
4656 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4657 around this problem.
4661 GDB now supports array constants that can be used in expressions typed in by
4662 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4663 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4666 The new directory `gdb/sparclite' contains a program that demonstrates
4667 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4669 * New native hosts supported
4671 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4672 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4674 * New targets supported
4676 AMD 29k family via UDI a29k-amd-udi or udi29k
4678 * New file formats supported
4680 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4681 HPUX core files, and SCO 3.2v2 core files.
4685 Attaching to processes now works again; thanks for the many bug reports.
4687 We have also stomped on a bunch of core dumps caused by
4688 printf_filtered("%s") problems.
4690 We eliminated a copyright problem on the rpc and ptrace header files
4691 for VxWorks, which was discovered at the last minute during the 4.7
4692 release. You should now be able to build a VxWorks GDB.
4694 You can now interrupt gdb while an attached process is running. This
4695 will cause the attached process to stop, and give control back to GDB.
4697 We fixed problems caused by using too many file descriptors
4698 for reading symbols from object files and libraries. This was
4699 especially a problem for programs that used many (~100) shared
4702 The `step' command now only enters a subroutine if there is line number
4703 information for the subroutine. Otherwise it acts like the `next'
4704 command. Previously, `step' would enter subroutines if there was
4705 any debugging information about the routine. This avoids problems
4706 when using `cc -g1' on MIPS machines.
4708 * Internal improvements
4710 GDB's internal interfaces have been improved to make it easier to support
4711 debugging of multiple languages in the future.
4713 GDB now uses a common structure for symbol information internally.
4714 Minimal symbols (derived from linkage symbols in object files), partial
4715 symbols (from a quick scan of debug information), and full symbols
4716 contain a common subset of information, making it easier to write
4717 shared code that handles any of them.
4719 * New command line options
4721 We now accept --silent as an alias for --quiet.
4725 The memory-mapped-malloc library is now licensed under the GNU Library
4726 General Public License.
4728 *** Changes in GDB-4.7:
4730 * Host/native/target split
4732 GDB has had some major internal surgery to untangle the support for
4733 hosts and remote targets. Now, when you configure GDB for a remote
4734 target, it will no longer load in all of the support for debugging
4735 local programs on the host. When fully completed and tested, this will
4736 ensure that arbitrary host/target combinations are possible.
4738 The primary conceptual shift is to separate the non-portable code in
4739 GDB into three categories. Host specific code is required any time GDB
4740 is compiled on that host, regardless of the target. Target specific
4741 code relates to the peculiarities of the target, but can be compiled on
4742 any host. Native specific code is everything else: it can only be
4743 built when the host and target are the same system. Child process
4744 handling and core file support are two common `native' examples.
4746 GDB's use of /proc for controlling Unix child processes is now cleaner.
4747 It has been split out into a single module under the `target_ops' vector,
4748 plus two native-dependent functions for each system that uses /proc.
4750 * New hosts supported
4752 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4753 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4754 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4756 * New targets supported
4758 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4759 68030 and CPU32 m68030-*-*, m68332-*-*
4761 * New native hosts supported
4763 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4764 (386bsd is not well tested yet)
4765 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4767 * New file formats supported
4769 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4770 supports reading of `a.out.adobe' object files, which are an a.out
4771 format extended with minimal information about multiple sections.
4775 `show copying' is the same as the old `info copying'.
4776 `show warranty' is the same as `info warrantee'.
4777 These were renamed for consistency. The old commands continue to work.
4779 `info handle' is a new alias for `info signals'.
4781 You can now define pre-command hooks, which attach arbitrary command
4782 scripts to any command. The commands in the hook will be executed
4783 prior to the user's command. You can also create a hook which will be
4784 executed whenever the program stops. See gdb.texinfo.
4788 We now deal with Cfront style name mangling, and can even extract type
4789 info from mangled symbols. GDB can automatically figure out which
4790 symbol mangling style your C++ compiler uses.
4792 Calling of methods and virtual functions has been improved as well.
4796 The crash that occured when debugging Sun Ansi-C compiled binaries is
4797 fixed. This was due to mishandling of the extra N_SO stabs output
4800 We also finally got Ultrix 4.2 running in house, and fixed core file
4801 support, with help from a dozen people on the net.
4803 John M. Farrell discovered that the reason that single-stepping was so
4804 slow on all of the Mips based platforms (primarily SGI and DEC) was
4805 that we were trying to demangle and lookup a symbol used for internal
4806 purposes on every instruction that was being stepped through. Changing
4807 the name of that symbol so that it couldn't be mistaken for a C++
4808 mangled symbol sped things up a great deal.
4810 Rich Pixley sped up symbol lookups in general by getting much smarter
4811 about when C++ symbol mangling is necessary. This should make symbol
4812 completion (TAB on the command line) much faster. It's not as fast as
4813 we'd like, but it's significantly faster than gdb-4.6.
4817 A new user controllable variable 'call_scratch_address' can
4818 specify the location of a scratch area to be used when GDB
4819 calls a function in the target. This is necessary because the
4820 usual method of putting the scratch area on the stack does not work
4821 in systems that have separate instruction and data spaces.
4823 We integrated changes to support the 29k UDI (Universal Debugger
4824 Interface), but discovered at the last minute that we didn't have all
4825 of the appropriate copyright paperwork. We are working with AMD to
4826 resolve this, and hope to have it available soon.
4830 We have sped up the remote serial line protocol, especially for targets
4831 with lots of registers. It now supports a new `expedited status' ('T')
4832 message which can be used in place of the existing 'S' status message.
4833 This allows the remote stub to send only the registers that GDB
4834 needs to make a quick decision about single-stepping or conditional
4835 breakpoints, eliminating the need to fetch the entire register set for
4836 each instruction being stepped through.
4838 The GDB remote serial protocol now implements a write-through cache for
4839 registers, only re-reading the registers if the target has run.
4841 There is also a new remote serial stub for SPARC processors. You can
4842 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4843 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4844 processor with a serial port.
4848 Configure.in files have become much easier to read and modify. A new
4849 `table driven' format makes it more obvious what configurations are
4850 supported, and what files each one uses.
4854 There is a new opcodes library which will eventually contain all of the
4855 disassembly routines and opcode tables. At present, it only contains
4856 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4857 disassembler (binutils/objdump) to share these routines.
4859 The libiberty library is now copylefted under the GNU Library General
4860 Public License. This allows more liberal use, and was done so libg++
4861 can use it. This makes no difference to GDB, since the Library License
4862 grants all the rights from the General Public License.
4866 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4867 reference to the stabs symbol info used by the debugger. It is (as far
4868 as we know) the only published document on this fascinating topic. We
4869 encourage you to read it, compare it to the stabs information on your
4870 system, and send improvements on the document in general (to
4871 bug-gdb@prep.ai.mit.edu).
4873 And, of course, many bugs have been fixed.
4876 *** Changes in GDB-4.6:
4878 * Better support for C++ function names
4880 GDB now accepts as input the "demangled form" of C++ overloaded function
4881 names and member function names, and can do command completion on such names
4882 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4883 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4884 Make use of command completion, it is your friend.
4886 GDB also now accepts a variety of C++ mangled symbol formats. They are
4887 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4888 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4889 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4890 for the list of formats.
4892 * G++ symbol mangling problem
4894 Recent versions of gcc have a bug in how they emit debugging information for
4895 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4896 directory) can be applied to gcc to fix the problem. Alternatively, if you
4897 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4898 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4899 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4902 * New 'maintenance' command
4904 All of the commands related to hacking GDB internals have been moved out of
4905 the main command set, and now live behind the 'maintenance' command. This
4906 can also be abbreviated as 'mt'. The following changes were made:
4908 dump-me -> maintenance dump-me
4909 info all-breakpoints -> maintenance info breakpoints
4910 printmsyms -> maintenance print msyms
4911 printobjfiles -> maintenance print objfiles
4912 printpsyms -> maintenance print psymbols
4913 printsyms -> maintenance print symbols
4915 The following commands are new:
4917 maintenance demangle Call internal GDB demangler routine to
4918 demangle a C++ link name and prints the result.
4919 maintenance print type Print a type chain for a given symbol
4921 * Change to .gdbinit file processing
4923 We now read the $HOME/.gdbinit file before processing the argv arguments
4924 (e.g. reading symbol files or core files). This allows global parameters to
4925 be set, which will apply during the symbol reading. The ./.gdbinit is still
4926 read after argv processing.
4928 * New hosts supported
4930 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4932 GNU/Linux support i386-unknown-linux or linux
4934 We are also including code to support the HP/PA running BSD and HPUX. This
4935 is almost guaranteed not to work, as we didn't have time to test or build it
4936 for this release. We are including it so that the more adventurous (or
4937 masochistic) of you can play with it. We also had major problems with the
4938 fact that the compiler that we got from HP doesn't support the -g option.
4941 * New targets supported
4943 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4945 * More smarts about finding #include files
4947 GDB now remembers the compilation directory for all include files, and for
4948 all files from which C is generated (like yacc and lex sources). This
4949 greatly improves GDB's ability to find yacc/lex sources, and include files,
4950 especially if you are debugging your program from a directory different from
4951 the one that contains your sources.
4953 We also fixed a bug which caused difficulty with listing and setting
4954 breakpoints in include files which contain C code. (In the past, you had to
4955 try twice in order to list an include file that you hadn't looked at before.)
4957 * Interesting infernals change
4959 GDB now deals with arbitrary numbers of sections, where the symbols for each
4960 section must be relocated relative to that section's landing place in the
4961 target's address space. This work was needed to support ELF with embedded
4962 stabs used by Solaris-2.0.
4964 * Bug fixes (of course!)
4966 There have been loads of fixes for the following things:
4967 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4968 i960, stabs, DOS(GO32), procfs, etc...
4970 See the ChangeLog for details.
4972 *** Changes in GDB-4.5:
4974 * New machines supported (host and target)
4976 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4978 SGI Irix-4.x mips-sgi-irix4 or iris4
4980 * New malloc package
4982 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4983 Mmalloc is capable of handling mutiple heaps of memory. It is also
4984 capable of saving a heap to a file, and then mapping it back in later.
4985 This can be used to greatly speedup the startup of GDB by using a
4986 pre-parsed symbol table which lives in a mmalloc managed heap. For
4987 more details, please read mmalloc/mmalloc.texi.
4991 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4992 'help info proc' for details.
4994 * MIPS ecoff symbol table format
4996 The code that reads MIPS symbol table format is now supported on all hosts.
4997 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
5000 * File name changes for MS-DOS
5002 Many files in the config directories have been renamed to make it easier to
5003 support GDB on MS-DOSe systems (which have very restrictive file name
5004 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
5005 environment) is close to working but has some remaining problems. Note
5006 that debugging of DOS programs is not supported, due to limitations
5007 in the ``operating system'', but it can be used to host cross-debugging.
5009 * Cross byte order fixes
5011 Many fixes have been made to support cross debugging of Sparc and MIPS
5012 targets from hosts whose byte order differs.
5014 * New -mapped and -readnow options
5016 If memory-mapped files are available on your system through the 'mmap'
5017 system call, you can use the -mapped option on the `file' or
5018 `symbol-file' commands to cause GDB to write the symbols from your
5019 program into a reusable file. If the program you are debugging is
5020 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5021 Future GDB debugging sessions will notice the presence of this file,
5022 and will quickly map in symbol information from it, rather than reading
5023 the symbol table from the executable program. Using the '-mapped'
5024 option in a GDB `file' or `symbol-file' command has the same effect as
5025 starting GDB with the '-mapped' command-line option.
5027 You can cause GDB to read the entire symbol table immediately by using
5028 the '-readnow' option with any of the commands that load symbol table
5029 information (or on the GDB command line). This makes the command
5030 slower, but makes future operations faster.
5032 The -mapped and -readnow options are typically combined in order to
5033 build a `fred.syms' file that contains complete symbol information.
5034 A simple GDB invocation to do nothing but build a `.syms' file for future
5037 gdb -batch -nx -mapped -readnow programname
5039 The `.syms' file is specific to the host machine on which GDB is run.
5040 It holds an exact image of GDB's internal symbol table. It cannot be
5041 shared across multiple host platforms.
5043 * longjmp() handling
5045 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5046 siglongjmp() without losing control. This feature has not yet been ported to
5047 all systems. It currently works on many 386 platforms, all MIPS-based
5048 platforms (SGI, DECstation, etc), and Sun3/4.
5052 Preliminary work has been put in to support the new Solaris OS from Sun. At
5053 this time, it can control and debug processes, but it is not capable of
5058 As always, many many bug fixes. The major areas were with g++, and mipsread.
5059 People using the MIPS-based platforms should experience fewer mysterious
5060 crashes and trashed symbol tables.
5062 *** Changes in GDB-4.4:
5064 * New machines supported (host and target)
5066 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5068 BSD Reno on Vax vax-dec-bsd
5069 Ultrix on Vax vax-dec-ultrix
5071 * New machines supported (target)
5073 AMD 29000 embedded, using EBMON a29k-none-none
5077 GDB continues to improve its handling of C++. `References' work better.
5078 The demangler has also been improved, and now deals with symbols mangled as
5079 per the Annotated C++ Reference Guide.
5081 GDB also now handles `stabs' symbol information embedded in MIPS
5082 `ecoff' symbol tables. Since the ecoff format was not easily
5083 extensible to handle new languages such as C++, this appeared to be a
5084 good way to put C++ debugging info into MIPS binaries. This option
5085 will be supported in the GNU C compiler, version 2, when it is
5088 * New features for SVR4
5090 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5091 shared libraries. Debugging dynamically linked programs should present
5092 only minor differences from debugging statically linked programs.
5094 The `info proc' command will print out information about any process
5095 on an SVR4 system (including the one you are debugging). At the moment,
5096 it prints the address mappings of the process.
5098 If you bring up GDB on another SVR4 system, please send mail to
5099 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5101 * Better dynamic linking support in SunOS
5103 Reading symbols from shared libraries which contain debugging symbols
5104 now works properly. However, there remain issues such as automatic
5105 skipping of `transfer vector' code during function calls, which
5106 make it harder to debug code in a shared library, than to debug the
5107 same code linked statically.
5111 GDB is now using the latest `getopt' routines from the FSF. This
5112 version accepts the -- prefix for options with long names. GDB will
5113 continue to accept the old forms (-option and +option) as well.
5114 Various single letter abbreviations for options have been explicity
5115 added to the option table so that they won't get overshadowed in the
5116 future by other options that begin with the same letter.
5120 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5121 Many assorted bugs have been handled. Many more remain to be handled.
5122 See the various ChangeLog files (primarily in gdb and bfd) for details.
5125 *** Changes in GDB-4.3:
5127 * New machines supported (host and target)
5129 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5130 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5131 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5133 * Almost SCO Unix support
5135 We had hoped to support:
5136 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5137 (except for core file support), but we discovered very late in the release
5138 that it has problems with process groups that render gdb unusable. Sorry
5139 about that. I encourage people to fix it and post the fixes.
5141 * Preliminary ELF and DWARF support
5143 GDB can read ELF object files on System V Release 4, and can handle
5144 debugging records for C, in DWARF format, in ELF files. This support
5145 is preliminary. If you bring up GDB on another SVR4 system, please
5146 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5151 GDB now uses the latest `readline' library. One user-visible change
5152 is that two tabs will list possible command completions, which previously
5153 required typing M-? (meta-question mark, or ESC ?).
5157 The `stepi' bug that many of you noticed has been squashed.
5158 Many bugs in C++ have been handled. Many more remain to be handled.
5159 See the various ChangeLog files (primarily in gdb and bfd) for details.
5161 * State of the MIPS world (in case you wondered):
5163 GDB can understand the symbol tables emitted by the compilers
5164 supplied by most vendors of MIPS-based machines, including DEC. These
5165 symbol tables are in a format that essentially nobody else uses.
5167 Some versions of gcc come with an assembler post-processor called
5168 mips-tfile. This program is required if you want to do source-level
5169 debugging of gcc-compiled programs. I believe FSF does not ship
5170 mips-tfile with gcc version 1, but it will eventually come with gcc
5173 Debugging of g++ output remains a problem. g++ version 1.xx does not
5174 really support it at all. (If you're lucky, you should be able to get
5175 line numbers and stack traces to work, but no parameters or local
5176 variables.) With some work it should be possible to improve the
5179 When gcc version 2 is released, you will have somewhat better luck.
5180 However, even then you will get confusing results for inheritance and
5183 We will eventually provide full debugging of g++ output on
5184 DECstations. This will probably involve some kind of stabs-in-ecoff
5185 encapulation, but the details have not been worked out yet.
5188 *** Changes in GDB-4.2:
5190 * Improved configuration
5192 Only one copy of `configure' exists now, and it is not self-modifying.
5193 Porting BFD is simpler.
5197 The `step' and `next' commands now only stop at the first instruction
5198 of a source line. This prevents the multiple stops that used to occur
5199 in switch statements, for-loops, etc. `Step' continues to stop if a
5200 function that has debugging information is called within the line.
5204 Lots of small bugs fixed. More remain.
5206 * New host supported (not target)
5208 Intel 386 PC clone running Mach i386-none-mach
5211 *** Changes in GDB-4.1:
5213 * Multiple source language support
5215 GDB now has internal scaffolding to handle several source languages.
5216 It determines the type of each source file from its filename extension,
5217 and will switch expression parsing and number formatting to match the
5218 language of the function in the currently selected stack frame.
5219 You can also specifically set the language to be used, with
5220 `set language c' or `set language modula-2'.
5224 GDB now has preliminary support for the GNU Modula-2 compiler,
5225 currently under development at the State University of New York at
5226 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5227 continue through the fall of 1991 and into 1992.
5229 Other Modula-2 compilers are currently not supported, and attempting to
5230 debug programs compiled with them will likely result in an error as the
5231 symbol table is read. Feel free to work on it, though!
5233 There are hooks in GDB for strict type checking and range checking,
5234 in the `Modula-2 philosophy', but they do not currently work.
5238 GDB can now write to executable and core files (e.g. patch
5239 a variable's value). You must turn this switch on, specify
5240 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5241 by assigning a new value to a variable. Modifications take
5244 * Automatic SunOS shared library reading
5246 When you run your program, GDB automatically determines where its
5247 shared libraries (if any) have been loaded, and reads their symbols.
5248 The `share' command is no longer needed. This also works when
5249 examining core files.
5253 You can specify the number of lines that the `list' command shows.
5256 * New machines supported (host and target)
5258 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5259 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5260 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5262 * New hosts supported (not targets)
5264 IBM RT/PC: romp-ibm-aix or rtpc
5266 * New targets supported (not hosts)
5268 AMD 29000 embedded with COFF a29k-none-coff
5269 AMD 29000 embedded with a.out a29k-none-aout
5270 Ultracomputer remote kernel debug a29k-nyu-kern
5272 * New remote interfaces
5278 *** Changes in GDB-4.0:
5282 Wide output is wrapped at good places to make the output more readable.
5284 Gdb now supports cross-debugging from a host machine of one type to a
5285 target machine of another type. Communication with the target system
5286 is over serial lines. The ``target'' command handles connecting to the
5287 remote system; the ``load'' command will download a program into the
5288 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5289 also supports debugging of realtime processes running under VxWorks,
5290 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5291 stub on the target system.
5293 New CPUs supported include the AMD 29000 and Intel 960.
5295 GDB now reads object files and symbol tables via a ``binary file''
5296 library, which allows a single copy of GDB to debug programs of multiple
5297 object file types such as a.out and coff.
5299 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5300 refcard.dvi and refcard.ps are available to format it).
5303 * Control-Variable user interface simplified
5305 All variables that control the operation of the debugger can be set
5306 by the ``set'' command, and displayed by the ``show'' command.
5308 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5309 ``Show prompt'' produces the response:
5310 Gdb's prompt is new-gdb=>.
5312 What follows are the NEW set commands. The command ``help set'' will
5313 print a complete list of old and new set commands. ``help set FOO''
5314 will give a longer description of the variable FOO. ``show'' will show
5315 all of the variable descriptions and their current settings.
5317 confirm on/off: Enables warning questions for operations that are
5318 hard to recover from, e.g. rerunning the program while
5319 it is already running. Default is ON.
5321 editing on/off: Enables EMACS style command line editing
5322 of input. Previous lines can be recalled with
5323 control-P, the current line can be edited with control-B,
5324 you can search for commands with control-R, etc.
5327 history filename NAME: NAME is where the gdb command history
5328 will be stored. The default is .gdb_history,
5329 or the value of the environment variable
5332 history size N: The size, in commands, of the command history. The
5333 default is 256, or the value of the environment variable
5336 history save on/off: If this value is set to ON, the history file will
5337 be saved after exiting gdb. If set to OFF, the
5338 file will not be saved. The default is OFF.
5340 history expansion on/off: If this value is set to ON, then csh-like
5341 history expansion will be performed on
5342 command line input. The default is OFF.
5344 radix N: Sets the default radix for input and output. It can be set
5345 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5346 in the current radix, so "set radix 10" is always a no-op.
5348 height N: This integer value is the number of lines on a page. Default
5349 is 24, the current `stty rows'' setting, or the ``li#''
5350 setting from the termcap entry matching the environment
5353 width N: This integer value is the number of characters on a line.
5354 Default is 80, the current `stty cols'' setting, or the ``co#''
5355 setting from the termcap entry matching the environment
5358 Note: ``set screensize'' is obsolete. Use ``set height'' and
5359 ``set width'' instead.
5361 print address on/off: Print memory addresses in various command displays,
5362 such as stack traces and structure values. Gdb looks
5363 more ``symbolic'' if you turn this off; it looks more
5364 ``machine level'' with it on. Default is ON.
5366 print array on/off: Prettyprint arrays. New convenient format! Default
5369 print demangle on/off: Print C++ symbols in "source" form if on,
5372 print asm-demangle on/off: Same, for assembler level printouts
5375 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5378 * Support for Epoch Environment.
5380 The epoch environment is a version of Emacs v18 with windowing. One
5381 new command, ``inspect'', is identical to ``print'', except that if you
5382 are running in the epoch environment, the value is printed in its own
5386 * Support for Shared Libraries
5388 GDB can now debug programs and core files that use SunOS shared libraries.
5389 Symbols from a shared library cannot be referenced
5390 before the shared library has been linked with the program (this
5391 happens after you type ``run'' and before the function main() is entered).
5392 At any time after this linking (including when examining core files
5393 from dynamically linked programs), gdb reads the symbols from each
5394 shared library when you type the ``sharedlibrary'' command.
5395 It can be abbreviated ``share''.
5397 sharedlibrary REGEXP: Load shared object library symbols for files
5398 matching a unix regular expression. No argument
5399 indicates to load symbols for all shared libraries.
5401 info sharedlibrary: Status of loaded shared libraries.
5406 A watchpoint stops execution of a program whenever the value of an
5407 expression changes. Checking for this slows down execution
5408 tremendously whenever you are in the scope of the expression, but is
5409 quite useful for catching tough ``bit-spreader'' or pointer misuse
5410 problems. Some machines such as the 386 have hardware for doing this
5411 more quickly, and future versions of gdb will use this hardware.
5413 watch EXP: Set a watchpoint (breakpoint) for an expression.
5415 info watchpoints: Information about your watchpoints.
5417 delete N: Deletes watchpoint number N (same as breakpoints).
5418 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5419 enable N: Re-enables watchpoint number N (same as breakpoints).
5422 * C++ multiple inheritance
5424 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5427 * C++ exception handling
5429 Gdb now supports limited C++ exception handling. Besides the existing
5430 ability to breakpoint on an exception handler, gdb can breakpoint on
5431 the raising of an exception (before the stack is peeled back to the
5434 catch FOO: If there is a FOO exception handler in the dynamic scope,
5435 set a breakpoint to catch exceptions which may be raised there.
5436 Multiple exceptions (``catch foo bar baz'') may be caught.
5438 info catch: Lists all exceptions which may be caught in the
5439 current stack frame.
5442 * Minor command changes
5444 The command ``call func (arg, arg, ...)'' now acts like the print
5445 command, except it does not print or save a value if the function's result
5446 is void. This is similar to dbx usage.
5448 The ``up'' and ``down'' commands now always print the frame they end up
5449 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5450 frames without printing.
5452 * New directory command
5454 'dir' now adds directories to the FRONT of the source search path.
5455 The path starts off empty. Source files that contain debug information
5456 about the directory in which they were compiled can be found even
5457 with an empty path; Sun CC and GCC include this information. If GDB can't
5458 find your source file in the current directory, type "dir .".
5460 * Configuring GDB for compilation
5462 For normal use, type ``./configure host''. See README or gdb.texinfo
5465 GDB now handles cross debugging. If you are remotely debugging between
5466 two different machines, type ``./configure host -target=targ''.
5467 Host is the machine where GDB will run; targ is the machine
5468 where the program that you are debugging will run.