1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.6
8 ** Frame filters and frame decorators have been added.
12 Nios II ELF nios2*-*-elf
13 Nios II GNU/Linux nios2*-*-linux
14 Texas Instruments MSP430 msp430*-*-elf
18 Like "catch throw", but catches a re-thrown exception.
20 Renamed from old "maint check-symtabs".
22 Perform consistency checks on symtabs.
24 Expand symtabs matching an optional regexp.
27 Display the details of GDB configure-time options.
29 maint set|show per-command
30 maint set|show per-command space
31 maint set|show per-command time
32 maint set|show per-command symtab
33 Enable display of per-command gdb resource usage.
37 set remote trace-status-packet
38 show remote trace-status-packet
39 Set/show the use of remote protocol qTStatus packet.
43 Control display of debugging messages related to Nios II targets.
47 Control whether target-assisted range stepping is enabled.
49 * You can now use a literal value 'unlimited' for options that
50 interpret 0 or -1 as meaning "unlimited". E.g., "set
51 trace-buffer-size unlimited" is now an alias for "set
52 trace-buffer-size -1" and "set height unlimited" is now an alias for
55 * New command-line options
57 Display the details of GDB configure-time options.
59 * The command 'tsave' can now support new option '-ctf' to save trace
60 buffer in Common Trace Format.
62 * Newly installed $prefix/bin/gcore acts as a shell interface for the
65 * GDB now implements the the C++ 'typeid' operator.
67 * The new convenience variable $_exception holds the exception being
68 thrown or caught at an exception-related catchpoint.
70 * The exception-related catchpoints, like "catch throw", now accept a
71 regular expression which can be used to filter exceptions by type.
75 ** The -trace-save MI command can optionally save trace buffer in Common
78 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
80 ** The command -data-list-register-values now accepts an optional
81 "--skip-unavailable" option. When used, only the available registers
84 ** The new command -trace-frame-collected dumps collected variables,
85 computed expressions, tvars, memory and registers in a traceframe.
87 * New system-wide configuration scripts
88 A GDB installation now provides scripts suitable for use as system-wide
89 configuration scripts for the following systems:
93 * GDB now supports target-assigned range stepping with remote targets.
94 This improves the performance of stepping source lines by reducing
95 the number of control packets from/to GDB. See "New remote packets"
98 * GDB now understands the element 'tvar' in the XML traceframe info.
99 It has the id of the collected trace state variables.
105 The vCont packet supports a new 'r' action, that tells the remote
106 stub to step through an address range itself, without GDB
107 involvemement at each single-step.
109 qXfer:libraries-svr4:read's annex
110 The previously unused annex of the qXfer:libraries-svr4:read packet
111 is now used to support passing an argument list. The remote stub
112 reports support for this argument list to GDB's qSupported query.
113 The defined arguments are "start" and "prev", used to reduce work
114 necessary for library list updating, resulting in significant
117 * New features in the GDB remote stub, GDBserver
119 ** GDBserver now supports target-assisted range stepping. Currently
120 enabled on x86/x86_64 GNU/Linux targets.
122 ** GDBserver now adds element 'tvar' in the XML in the reply to
123 'qXfer:traceframe-info:read'. It has the id of the collected
124 trace state variables.
126 *** Changes in GDB 7.6
128 * Target record has been renamed to record-full.
129 Record/replay is now enabled with the "record full" command.
130 This also affects settings that are associated with full record/replay
131 that have been moved from "set/show record" to "set/show record full":
133 set|show record full insn-number-max
134 set|show record full stop-at-limit
135 set|show record full memory-query
137 * A new record target "record-btrace" has been added. The new target
138 uses hardware support to record the control-flow of a process. It
139 does not support replaying the execution, but it implements the
140 below new commands for investigating the recorded execution log.
141 This new recording method can be enabled using:
145 The "record-btrace" target is only available on Intel Atom processors
146 and requires a Linux kernel 2.6.32 or later.
148 * Two new commands have been added for record/replay to give information
149 about the recorded execution without having to replay the execution.
150 The commands are only supported by "record btrace".
152 record instruction-history prints the execution history at
153 instruction granularity
155 record function-call-history prints the execution history at
158 * New native configurations
160 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
161 FreeBSD/powerpc powerpc*-*-freebsd
162 x86_64/Cygwin x86_64-*-cygwin*
163 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
167 ARM AArch64 aarch64*-*-elf
168 ARM AArch64 GNU/Linux aarch64*-*-linux
169 Lynx 178 PowerPC powerpc-*-lynx*178
170 x86_64/Cygwin x86_64-*-cygwin*
171 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
173 * If the configured location of system.gdbinit file (as given by the
174 --with-system-gdbinit option at configure time) is in the
175 data-directory (as specified by --with-gdb-datadir at configure
176 time) or in one of its subdirectories, then GDB will look for the
177 system-wide init file in the directory specified by the
178 --data-directory command-line option.
180 * New command line options:
182 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
183 other initialization files, unlike -nx which disables all of them.
185 * Removed command line options
187 -epoch This was used by the gdb mode in Epoch, an ancient fork of
190 * The 'ptype' and 'whatis' commands now accept an argument to control
193 * 'info proc' now works on some core files.
197 ** Vectors can be created with gdb.Type.vector.
199 ** Python's atexit.register now works in GDB.
201 ** Types can be pretty-printed via a Python API.
203 ** Python 3 is now supported (in addition to Python 2.4 or later)
205 ** New class gdb.Architecture exposes GDB's internal representation
206 of architecture in the Python API.
208 ** New method Frame.architecture returns the gdb.Architecture object
209 corresponding to the frame's architecture.
211 * New Python-based convenience functions:
213 ** $_memeq(buf1, buf2, length)
214 ** $_streq(str1, str2)
216 ** $_regex(str, regex)
218 * The 'cd' command now defaults to using '~' (the home directory) if not
221 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
222 default for GCC since November 2000.
224 * The command 'forward-search' can now be abbreviated as 'fo'.
226 * The command 'info tracepoints' can now display 'installed on target'
227 or 'not installed on target' for each non-pending location of tracepoint.
229 * New configure options
231 --enable-libmcheck/--disable-libmcheck
232 By default, development versions are built with -lmcheck on hosts
233 that support it, in order to help track memory corruption issues.
234 Release versions, on the other hand, are built without -lmcheck
235 by default. The --enable-libmcheck/--disable-libmcheck configure
236 options allow the user to override that default.
237 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
238 This configure option allows the user to build GDB with
239 libbabeltrace using which GDB can read Common Trace Format data.
241 * New commands (for set/show, see "New options" below)
244 Catch signals. This is similar to "handle", but allows commands and
245 conditions to be attached.
248 List the BFDs known to GDB.
250 python-interactive [command]
252 Start a Python interactive prompt, or evaluate the optional command
253 and print the result of expressions.
256 "py" is a new alias for "python".
258 enable type-printer [name]...
259 disable type-printer [name]...
260 Enable or disable type printers.
264 ** For the Renesas Super-H architecture, the "regs" command has been removed
265 (has been deprecated in GDB 7.5), and "info all-registers" should be used
270 set print type methods (on|off)
271 show print type methods
272 Control whether method declarations are displayed by "ptype".
273 The default is to show them.
275 set print type typedefs (on|off)
276 show print type typedefs
277 Control whether typedef definitions are displayed by "ptype".
278 The default is to show them.
280 set filename-display basename|relative|absolute
281 show filename-display
282 Control the way in which filenames is displayed.
283 The default is "relative", which preserves previous behavior.
285 set trace-buffer-size
286 show trace-buffer-size
287 Request target to change the size of trace buffer.
289 set remote trace-buffer-size-packet auto|on|off
290 show remote trace-buffer-size-packet
291 Control the use of the remote protocol `QTBuffer:size' packet.
295 Control display of debugging messages related to ARM AArch64.
298 set debug coff-pe-read
299 show debug coff-pe-read
300 Control display of debugging messages related to reading of COFF/PE
305 Control display of debugging messages related to Mach-O symbols
308 set debug notification
309 show debug notification
310 Control display of debugging info for async remote notification.
314 ** Command parameter changes are now notified using new async record
315 "=cmd-param-changed".
316 ** Trace frame changes caused by command "tfind" are now notified using
317 new async record "=traceframe-changed".
318 ** The creation, deletion and modification of trace state variables
319 are now notified using new async records "=tsv-created",
320 "=tsv-deleted" and "=tsv-modified".
321 ** The start and stop of process record are now notified using new
322 async record "=record-started" and "=record-stopped".
323 ** Memory changes are now notified using new async record
325 ** The data-disassemble command response will include a "fullname" field
326 containing the absolute file name when source has been requested.
327 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
328 command, to allow pattern filling of memory areas.
329 ** New commands "-catch-load"/"-catch-unload" added for intercepting
330 library load/unload events.
331 ** The response to breakpoint commands and breakpoint async records
332 includes an "installed" field containing a boolean state about each
333 non-pending tracepoint location is whether installed on target or not.
334 ** Output of the "-trace-status" command includes a "trace-file" field
335 containing the name of the trace file being examined. This field is
336 optional, and only present when examining a trace file.
337 ** The "fullname" field is now always present along with the "file" field,
338 even if the file cannot be found by GDB.
340 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
341 You must have the LZMA library available when configuring GDB for this
342 feature to be enabled. For more information, see:
343 http://fedoraproject.org/wiki/Features/MiniDebugInfo
348 Set the size of trace buffer. The remote stub reports support for this
349 packet to gdb's qSupported query.
352 Enable Branch Trace Store (BTS)-based branch tracing for the current
353 thread. The remote stub reports support for this packet to gdb's
357 Disable branch tracing for the current thread. The remote stub reports
358 support for this packet to gdb's qSupported query.
361 Read the traced branches for the current thread. The remote stub
362 reports support for this packet to gdb's qSupported query.
364 *** Changes in GDB 7.5
366 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
367 for more x32 ABI info.
369 * GDB now supports access to MIPS DSP registers on Linux targets.
371 * GDB now supports debugging microMIPS binaries.
373 * The "info os" command on GNU/Linux can now display information on
374 several new classes of objects managed by the operating system:
375 "info os procgroups" lists process groups
376 "info os files" lists file descriptors
377 "info os sockets" lists internet-domain sockets
378 "info os shm" lists shared-memory regions
379 "info os semaphores" lists semaphores
380 "info os msg" lists message queues
381 "info os modules" lists loaded kernel modules
383 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
384 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
385 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
386 options and inspect the probe arguments using the new $_probe_arg family
387 of convenience variables. You can obtain more information about SystemTap
388 in <http://sourceware.org/systemtap/>.
390 * GDB now supports reversible debugging on ARM, it allows you to
391 debug basic ARM and THUMB instructions, and provides
392 record/replay support.
394 * The option "symbol-reloading" has been deleted as it is no longer used.
398 ** GDB commands implemented in Python can now be put in command class
401 ** The "maint set python print-stack on|off" is now deleted.
403 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
404 apply "flag enum"-style pretty-printing to any enum.
406 ** gdb.lookup_symbol can now work when there is no current frame.
408 ** gdb.Symbol now has a 'line' attribute, holding the line number in
409 the source at which the symbol was defined.
411 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
412 method 'value'. The former indicates whether the symbol needs a
413 frame in order to compute its value, and the latter computes the
416 ** A new method 'referenced_value' on gdb.Value objects which can
417 dereference pointer as well as C++ reference values.
419 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
420 which return the global and static blocks (as gdb.Block objects),
421 of the underlying symbol table, respectively.
423 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
424 object associated with a PC value.
426 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
427 of the address range occupied by code for the current source line.
429 * Go language support.
430 GDB now supports debugging programs written in the Go programming
433 * GDBserver now supports stdio connections.
434 E.g. (gdb) target remote | ssh myhost gdbserver - hello
436 * The binary "gdbtui" can no longer be built or installed.
437 Use "gdb -tui" instead.
439 * GDB will now print "flag" enums specially. A flag enum is one where
440 all the enumerator values have no bits in common when pairwise
441 "and"ed. When printing a value whose type is a flag enum, GDB will
442 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
443 (gdb) print (enum E) 3
446 * The filename part of a linespec will now match trailing components
447 of a source file name. For example, "break gcc/expr.c:1000" will
448 now set a breakpoint in build/gcc/expr.c, but not
451 * The "info proc" and "generate-core-file" commands will now also
452 work on remote targets connected to GDBserver on Linux.
454 * The command "info catch" has been removed. It has been disabled
457 * The "catch exception" and "catch assert" commands now accept
458 a condition at the end of the command, much like the "break"
459 command does. For instance:
461 (gdb) catch exception Constraint_Error if Barrier = True
463 Previously, it was possible to add a condition to such catchpoints,
464 but it had to be done as a second step, after the catchpoint had been
465 created, using the "condition" command.
467 * The "info static-tracepoint-marker" command will now also work on
468 native Linux targets with in-process agent.
470 * GDB can now set breakpoints on inlined functions.
472 * The .gdb_index section has been updated to include symbols for
473 inlined functions. GDB will ignore older .gdb_index sections by
474 default, which could cause symbol files to be loaded more slowly
475 until their .gdb_index sections can be recreated. The new command
476 "set use-deprecated-index-sections on" will cause GDB to use any older
477 .gdb_index sections it finds. This will restore performance, but the
478 ability to set breakpoints on inlined functions will be lost in symbol
479 files with older .gdb_index sections.
481 The .gdb_index section has also been updated to record more information
482 about each symbol. This speeds up the "info variables", "info functions"
483 and "info types" commands when used with programs having the .gdb_index
484 section, as well as speeding up debugging with shared libraries using
485 the .gdb_index section.
487 * Ada support for GDB/MI Variable Objects has been added.
489 * GDB can now support 'breakpoint always-inserted mode' in 'record'
494 ** New command -info-os is the MI equivalent of "info os".
496 ** Output logs ("set logging" and related) now include MI output.
500 ** "set use-deprecated-index-sections on|off"
501 "show use-deprecated-index-sections on|off"
502 Controls the use of deprecated .gdb_index sections.
504 ** "catch load" and "catch unload" can be used to stop when a shared
505 library is loaded or unloaded, respectively.
507 ** "enable count" can be used to auto-disable a breakpoint after
510 ** "info vtbl" can be used to show the virtual method tables for
511 C++ and Java objects.
513 ** "explore" and its sub commands "explore value" and "explore type"
514 can be used to reccursively explore values and types of
515 expressions. These commands are available only if GDB is
516 configured with '--with-python'.
518 ** "info auto-load" shows status of all kinds of auto-loaded files,
519 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
520 sequences of commands files, "info auto-load python-scripts"
521 shows status of auto-loading Python script files,
522 "info auto-load local-gdbinit" shows status of loading init file
523 (.gdbinit) from current directory and "info auto-load libthread-db" shows
524 status of inferior specific thread debugging shared library loading.
526 ** "info auto-load-scripts", "set auto-load-scripts on|off"
527 and "show auto-load-scripts" commands have been deprecated, use their
528 "info auto-load python-scripts", "set auto-load python-scripts on|off"
529 and "show auto-load python-scripts" counterparts instead.
531 ** "dprintf location,format,args..." creates a dynamic printf, which
532 is basically a breakpoint that does a printf and immediately
533 resumes your program's execution, so it is like a printf that you
534 can insert dynamically at runtime instead of at compiletime.
536 ** "set print symbol"
538 Controls whether GDB attempts to display the symbol, if any,
539 corresponding to addresses it prints. This defaults to "on", but
540 you can set it to "off" to restore GDB's previous behavior.
542 * Deprecated commands
544 ** For the Renesas Super-H architecture, the "regs" command has been
545 deprecated, and "info all-registers" should be used instead.
549 Renesas RL78 rl78-*-elf
550 HP OpenVMS ia64 ia64-hp-openvms*
552 * GDBserver supports evaluation of breakpoint conditions. When
553 support is advertised by GDBserver, GDB may be told to send the
554 breakpoint conditions in bytecode form to GDBserver. GDBserver
555 will only report the breakpoint trigger to GDB when its condition
561 show mips compression
562 Select the compressed ISA encoding used in functions that have no symbol
563 information available. The encoding can be set to either of:
566 and is updated automatically from ELF file flags if available.
568 set breakpoint condition-evaluation
569 show breakpoint condition-evaluation
570 Control whether breakpoint conditions are evaluated by GDB ("host") or by
571 GDBserver ("target"). Default option "auto" chooses the most efficient
573 This option can improve debugger efficiency depending on the speed of the
577 Disable auto-loading globally.
580 Show auto-loading setting of all kinds of auto-loaded files.
582 set auto-load gdb-scripts on|off
583 show auto-load gdb-scripts
584 Control auto-loading of GDB canned sequences of commands files.
586 set auto-load python-scripts on|off
587 show auto-load python-scripts
588 Control auto-loading of Python script files.
590 set auto-load local-gdbinit on|off
591 show auto-load local-gdbinit
592 Control loading of init file (.gdbinit) from current directory.
594 set auto-load libthread-db on|off
595 show auto-load libthread-db
596 Control auto-loading of inferior specific thread debugging shared library.
598 set auto-load scripts-directory <dir1>[:<dir2>...]
599 show auto-load scripts-directory
600 Set a list of directories from which to load auto-loaded scripts.
601 Automatically loaded Python scripts and GDB scripts are located in one
602 of the directories listed by this option.
603 The delimiter (':' above) may differ according to the host platform.
605 set auto-load safe-path <dir1>[:<dir2>...]
606 show auto-load safe-path
607 Set a list of directories from which it is safe to auto-load files.
608 The delimiter (':' above) may differ according to the host platform.
610 set debug auto-load on|off
612 Control display of debugging info for auto-loading the files above.
614 set dprintf-style gdb|call|agent
616 Control the way in which a dynamic printf is performed; "gdb"
617 requests a GDB printf command, while "call" causes dprintf to call a
618 function in the inferior. "agent" requests that the target agent
619 (such as GDBserver) do the printing.
621 set dprintf-function <expr>
622 show dprintf-function
623 set dprintf-channel <expr>
625 Set the function and optional first argument to the call when using
626 the "call" style of dynamic printf.
628 set disconnected-dprintf on|off
629 show disconnected-dprintf
630 Control whether agent-style dynamic printfs continue to be in effect
631 after GDB disconnects.
633 * New configure options
636 Configure default value for the 'set auto-load scripts-directory'
637 setting above. It defaults to '$debugdir:$datadir/auto-load',
638 $debugdir representing global debugging info directories (available
639 via 'show debug-file-directory') and $datadir representing GDB's data
640 directory (available via 'show data-directory').
642 --with-auto-load-safe-path
643 Configure default value for the 'set auto-load safe-path' setting
644 above. It defaults to the --with-auto-load-dir setting.
646 --without-auto-load-safe-path
647 Set 'set auto-load safe-path' to '/', effectively disabling this
652 z0/z1 conditional breakpoints extension
654 The z0/z1 breakpoint insertion packets have been extended to carry
655 a list of conditional expressions over to the remote stub depending on the
656 condition evaluation mode. The use of this extension can be controlled
657 via the "set remote conditional-breakpoints-packet" command.
661 Specify the signals which the remote stub may pass to the debugged
662 program without GDB involvement.
664 * New command line options
666 --init-command=FILE, -ix Like --command, -x but execute it
667 before loading inferior.
668 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
669 execute it before loading inferior.
671 *** Changes in GDB 7.4
673 * GDB now handles ambiguous linespecs more consistently; the existing
674 FILE:LINE support has been expanded to other types of linespecs. A
675 breakpoint will now be set on all matching locations in all
676 inferiors, and locations will be added or removed according to
679 * GDB now allows you to skip uninteresting functions and files when
680 stepping with the "skip function" and "skip file" commands.
682 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
683 and "show remote hardware-watchpoint-length-limit". These allows to
684 set or show the maximum length limit (in bytes) of a remote
685 target hardware watchpoint.
687 This allows e.g. to use "unlimited" hardware watchpoints with the
688 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
689 watchpoints are slower than real hardware watchpoints but are
690 significantly faster than gdb software watchpoints.
694 ** The register_pretty_printer function in module gdb.printing now takes
695 an optional `replace' argument. If True, the new printer replaces any
698 ** The "maint set python print-stack on|off" command has been
699 deprecated and will be deleted in GDB 7.5.
700 A new command: "set python print-stack none|full|message" has
701 replaced it. Additionally, the default for "print-stack" is
702 now "message", which just prints the error message without
705 ** A prompt substitution hook (prompt_hook) is now available to the
708 ** A new Python module, gdb.prompt has been added to the GDB Python
709 modules library. This module provides functionality for
710 escape sequences in prompts (used by set/show
711 extended-prompt). These escape sequences are replaced by their
714 ** Python commands and convenience-functions located in
715 'data-directory'/python/gdb/command and
716 'data-directory'/python/gdb/function are now automatically loaded
719 ** Blocks now provide four new attributes. global_block and
720 static_block will return the global and static blocks
721 respectively. is_static and is_global are boolean attributes
722 that indicate if the block is one of those two types.
724 ** Symbols now provide the "type" attribute, the type of the symbol.
726 ** The "gdb.breakpoint" function has been deprecated in favor of
729 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
730 of a function. This class is based on the "finish" command
731 available in the CLI.
733 ** Type objects for struct and union types now allow access to
734 the fields using standard Python dictionary (mapping) methods.
735 For example, "some_type['myfield']" now works, as does
738 ** A new event "gdb.new_objfile" has been added, triggered by loading a
741 ** A new function, "deep_items" has been added to the gdb.types
742 module in the GDB Python modules library. This function returns
743 an iterator over the fields of a struct or union type. Unlike
744 the standard Python "iteritems" method, it will recursively traverse
745 any anonymous fields.
749 ** "*stopped" events can report several new "reason"s, such as
752 ** Breakpoint changes are now notified using new async records, like
753 "=breakpoint-modified".
755 ** New command -ada-task-info.
757 * libthread-db-search-path now supports two special values: $sdir and $pdir.
758 $sdir specifies the default system locations of shared libraries.
759 $pdir specifies the directory where the libpthread used by the application
762 GDB no longer looks in $sdir and $pdir after it has searched the directories
763 mentioned in libthread-db-search-path. If you want to search those
764 directories, they must be specified in libthread-db-search-path.
765 The default value of libthread-db-search-path on GNU/Linux and Solaris
766 systems is now "$sdir:$pdir".
768 $pdir is not supported by gdbserver, it is currently ignored.
769 $sdir is supported by gdbserver.
771 * New configure option --with-iconv-bin.
772 When using the internationalization support like the one in the GNU C
773 library, GDB will invoke the "iconv" program to get a list of supported
774 character sets. If this program lives in a non-standard location, one can
775 use this option to specify where to find it.
777 * When natively debugging programs on PowerPC BookE processors running
778 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
779 watchpoints, which specify a mask in addition to an address to watch.
780 The mask specifies that some bits of an address (the bits which are
781 reset in the mask) should be ignored when matching the address accessed
782 by the inferior against the watchpoint address. See the "PowerPC Embedded"
783 section in the user manual for more details.
785 * The new option --once causes GDBserver to stop listening for connections once
786 the first connection is made. The listening port used by GDBserver will
787 become available after that.
789 * New commands "info macros" and "alias" have been added.
791 * New function parameters suffix @entry specifies value of function parameter
792 at the time the function got called. Entry values are available only since
798 "!" is now an alias of the "shell" command.
799 Note that no space is needed between "!" and SHELL COMMAND.
803 watch EXPRESSION mask MASK_VALUE
804 The watch command now supports the mask argument which allows creation
805 of masked watchpoints, if the current architecture supports this feature.
807 info auto-load-scripts [REGEXP]
808 This command was formerly named "maintenance print section-scripts".
809 It is now generally useful and is no longer a maintenance-only command.
811 info macro [-all] [--] MACRO
812 The info macro command has new options `-all' and `--'. The first for
813 printing all definitions of a macro. The second for explicitly specifying
814 the end of arguments and the beginning of the macro name in case the macro
815 name starts with a hyphen.
817 collect[/s] EXPRESSIONS
818 The tracepoint collect command now takes an optional modifier "/s"
819 that directs it to dereference pointer-to-character types and
820 collect the bytes of memory up to a zero byte. The behavior is
821 similar to what you see when you use the regular print command on a
822 string. An optional integer following the "/s" sets a bound on the
823 number of bytes that will be collected.
826 The trace start command now interprets any supplied arguments as a
827 note to be recorded with the trace run, with an effect similar to
828 setting the variable trace-notes.
831 The trace stop command now interprets any arguments as a note to be
832 mentioned along with the tstatus report that the trace was stopped
833 with a command. The effect is similar to setting the variable
836 * Tracepoints can now be enabled and disabled at any time after a trace
837 experiment has been started using the standard "enable" and "disable"
838 commands. It is now possible to start a trace experiment with no enabled
839 tracepoints; GDB will display a warning, but will allow the experiment to
840 begin, assuming that tracepoints will be enabled as needed while the trace
843 * Fast tracepoints on 32-bit x86-architectures can now be placed at
844 locations with 4-byte instructions, when they were previously
845 limited to locations with instructions of 5 bytes or longer.
849 set debug dwarf2-read
850 show debug dwarf2-read
851 Turns on or off display of debugging messages related to reading
852 DWARF debug info. The default is off.
854 set debug symtab-create
855 show debug symtab-create
856 Turns on or off display of debugging messages related to symbol table
857 creation. The default is off.
861 Set the GDB prompt, and allow escape sequences to be inserted to
862 display miscellaneous information (see 'help set extended-prompt'
863 for the list of sequences). This prompt (and any information
864 accessed through the escape sequences) is updated every time the
867 set print entry-values (both|compact|default|if-needed|no|only|preferred)
868 show print entry-values
869 Set printing of frame argument values at function entry. In some cases
870 GDB can determine the value of function argument which was passed by the
871 function caller, even if the value was modified inside the called function.
873 set debug entry-values
874 show debug entry-values
875 Control display of debugging info for determining frame argument values at
876 function entry and virtual tail call frames.
878 set basenames-may-differ
879 show basenames-may-differ
880 Set whether a source file may have multiple base names.
881 (A "base name" is the name of a file with the directory part removed.
882 Example: The base name of "/home/user/hello.c" is "hello.c".)
883 If set, GDB will canonicalize file names (e.g., expand symlinks)
884 before comparing them. Canonicalization is an expensive operation,
885 but it allows the same file be known by more than one base name.
886 If not set (the default), all source files are assumed to have just
887 one base name, and gdb will do file name comparisons more efficiently.
893 Set a user name and notes for the current and any future trace runs.
894 This is useful for long-running and/or disconnected traces, to
895 inform others (or yourself) as to who is running the trace, supply
896 contact information, or otherwise explain what is going on.
899 show trace-stop-notes
900 Set a note attached to the trace run, that is displayed when the
901 trace has been stopped by a tstop command. This is useful for
902 instance as an explanation, if you are stopping a trace run that was
903 started by someone else.
909 Dynamically enable a tracepoint in a started trace experiment.
913 Dynamically disable a tracepoint in a started trace experiment.
917 Set the user and notes of the trace run.
921 Query the current status of a tracepoint.
925 Query the minimum length of instruction at which a fast tracepoint may
928 * Dcache size (number of lines) and line-size are now runtime-configurable
929 via "set dcache line" and "set dcache line-size" commands.
933 Texas Instruments TMS320C6x tic6x-*-*
937 Renesas RL78 rl78-*-elf
939 *** Changes in GDB 7.3.1
941 * The build failure for NetBSD and OpenBSD targets have now been fixed.
943 *** Changes in GDB 7.3
945 * GDB has a new command: "thread find [REGEXP]".
946 It finds the thread id whose name, target id, or thread extra info
947 matches the given regular expression.
949 * The "catch syscall" command now works on mips*-linux* targets.
951 * The -data-disassemble MI command now supports modes 2 and 3 for
952 dumping the instruction opcodes.
954 * New command line options
956 -data-directory DIR Specify DIR as the "data-directory".
957 This is mostly for testing purposes.
959 * The "maint set python auto-load on|off" command has been renamed to
960 "set auto-load-scripts on|off".
962 * GDB has a new command: "set directories".
963 It is like the "dir" command except that it replaces the
964 source path list instead of augmenting it.
966 * GDB now understands thread names.
968 On GNU/Linux, "info threads" will display the thread name as set by
969 prctl or pthread_setname_np.
971 There is also a new command, "thread name", which can be used to
972 assign a name internally for GDB to display.
975 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
976 has been integrated into GDB.
980 ** The function gdb.Write now accepts an optional keyword 'stream'.
981 This keyword, when provided, will direct the output to either
982 stdout, stderr, or GDB's logging output.
984 ** Parameters can now be be sub-classed in Python, and in particular
985 you may implement the get_set_doc and get_show_doc functions.
986 This improves how Parameter set/show documentation is processed
987 and allows for more dynamic content.
989 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
990 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
991 have an is_valid method.
993 ** Breakpoints can now be sub-classed in Python, and in particular
994 you may implement a 'stop' function that is executed each time
995 the inferior reaches that breakpoint.
997 ** New function gdb.lookup_global_symbol looks up a global symbol.
999 ** GDB values in Python are now callable if the value represents a
1000 function. For example, if 'some_value' represents a function that
1001 takes two integer parameters and returns a value, you can call
1002 that function like so:
1004 result = some_value (10,20)
1006 ** Module gdb.types has been added.
1007 It contains a collection of utilities for working with gdb.Types objects:
1008 get_basic_type, has_field, make_enum_dict.
1010 ** Module gdb.printing has been added.
1011 It contains utilities for writing and registering pretty-printers.
1012 New classes: PrettyPrinter, SubPrettyPrinter,
1013 RegexpCollectionPrettyPrinter.
1014 New function: register_pretty_printer.
1016 ** New commands "info pretty-printers", "enable pretty-printer" and
1017 "disable pretty-printer" have been added.
1019 ** gdb.parameter("directories") is now available.
1021 ** New function gdb.newest_frame returns the newest frame in the
1024 ** The gdb.InferiorThread class has a new "name" attribute. This
1025 holds the thread's name.
1027 ** Python Support for Inferior events.
1028 Python scripts can add observers to be notified of events
1029 occurring in the process being debugged.
1030 The following events are currently supported:
1031 - gdb.events.cont Continue event.
1032 - gdb.events.exited Inferior exited event.
1033 - gdb.events.stop Signal received, and Breakpoint hit events.
1037 ** GDB now puts template parameters in scope when debugging in an
1038 instantiation. For example, if you have:
1040 template<int X> int func (void) { return X; }
1042 then if you step into func<5>, "print X" will show "5". This
1043 feature requires proper debuginfo support from the compiler; it
1044 was added to GCC 4.5.
1046 ** The motion commands "next", "finish", "until", and "advance" now
1047 work better when exceptions are thrown. In particular, GDB will
1048 no longer lose control of the inferior; instead, the GDB will
1049 stop the inferior at the point at which the exception is caught.
1050 This functionality requires a change in the exception handling
1051 code that was introduced in GCC 4.5.
1053 * GDB now follows GCC's rules on accessing volatile objects when
1054 reading or writing target state during expression evaluation.
1055 One notable difference to prior behavior is that "print x = 0"
1056 no longer generates a read of x; the value of the assignment is
1057 now always taken directly from the value being assigned.
1059 * GDB now has some support for using labels in the program's source in
1060 linespecs. For instance, you can use "advance label" to continue
1061 execution to a label.
1063 * GDB now has support for reading and writing a new .gdb_index
1064 section. This section holds a fast index of DWARF debugging
1065 information and can be used to greatly speed up GDB startup and
1066 operation. See the documentation for `save gdb-index' for details.
1068 * The "watch" command now accepts an optional "-location" argument.
1069 When used, this causes GDB to watch the memory referred to by the
1070 expression. Such a watchpoint is never deleted due to it going out
1073 * GDB now supports thread debugging of core dumps on GNU/Linux.
1075 GDB now activates thread debugging using the libthread_db library
1076 when debugging GNU/Linux core dumps, similarly to when debugging
1077 live processes. As a result, when debugging a core dump file, GDB
1078 is now able to display pthread_t ids of threads. For example, "info
1079 threads" shows the same output as when debugging the process when it
1080 was live. In earlier releases, you'd see something like this:
1083 * 1 LWP 6780 main () at main.c:10
1085 While now you see this:
1088 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1090 It is also now possible to inspect TLS variables when debugging core
1093 When debugging a core dump generated on a machine other than the one
1094 used to run GDB, you may need to point GDB at the correct
1095 libthread_db library with the "set libthread-db-search-path"
1096 command. See the user manual for more details on this command.
1098 * When natively debugging programs on PowerPC BookE processors running
1099 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1100 which stop execution of the inferior whenever it executes an instruction
1101 at any address within the specified range. See the "PowerPC Embedded"
1102 section in the user manual for more details.
1104 * New features in the GDB remote stub, GDBserver
1106 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1107 and i686 LynxOS (version 5.x).
1109 ** GDBserver is now supported on Blackfin Linux.
1111 * New native configurations
1113 ia64 HP-UX ia64-*-hpux*
1117 Analog Devices, Inc. Blackfin Processor bfin-*
1119 * Ada task switching is now supported on sparc-elf targets when
1120 debugging a program using the Ravenscar Profile. For more information,
1121 see the "Tasking Support when using the Ravenscar Profile" section
1122 in the GDB user manual.
1124 * Guile support was removed.
1126 * New features in the GNU simulator
1128 ** The --map-info flag lists all known core mappings.
1130 ** CFI flashes may be simulated via the "cfi" device.
1132 *** Changes in GDB 7.2
1134 * Shared library support for remote targets by default
1136 When GDB is configured for a generic, non-OS specific target, like
1137 for example, --target=arm-eabi or one of the many *-*-elf targets,
1138 GDB now queries remote stubs for loaded shared libraries using the
1139 `qXfer:libraries:read' packet. Previously, shared library support
1140 was always disabled for such configurations.
1144 ** Argument Dependent Lookup (ADL)
1146 In C++ ADL lookup directs function search to the namespaces of its
1147 arguments even if the namespace has not been imported.
1157 Here the compiler will search for `foo' in the namespace of 'b'
1158 and find A::foo. GDB now supports this. This construct is commonly
1159 used in the Standard Template Library for operators.
1161 ** Improved User Defined Operator Support
1163 In addition to member operators, GDB now supports lookup of operators
1164 defined in a namespace and imported with a `using' directive, operators
1165 defined in the global scope, operators imported implicitly from an
1166 anonymous namespace, and the ADL operators mentioned in the previous
1168 GDB now also supports proper overload resolution for all the previously
1169 mentioned flavors of operators.
1171 ** static const class members
1173 Printing of static const class members that are initialized in the
1174 class definition has been fixed.
1176 * Windows Thread Information Block access.
1178 On Windows targets, GDB now supports displaying the Windows Thread
1179 Information Block (TIB) structure. This structure is visible either
1180 by using the new command `info w32 thread-information-block' or, by
1181 dereferencing the new convenience variable named `$_tlb', a
1182 thread-specific pointer to the TIB. This feature is also supported
1183 when remote debugging using GDBserver.
1185 * Static tracepoints
1187 Static tracepoints are calls in the user program into a tracing
1188 library. One such library is a port of the LTTng kernel tracer to
1189 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1190 When debugging with GDBserver, GDB now supports combining the GDB
1191 tracepoint machinery with such libraries. For example: the user can
1192 use GDB to probe a static tracepoint marker (a call from the user
1193 program into the tracing library) with the new "strace" command (see
1194 "New commands" below). This creates a "static tracepoint" in the
1195 breakpoint list, that can be manipulated with the same feature set
1196 as fast and regular tracepoints. E.g., collect registers, local and
1197 global variables, collect trace state variables, and define
1198 tracepoint conditions. In addition, the user can collect extra
1199 static tracepoint marker specific data, by collecting the new
1200 $_sdata internal variable. When analyzing the trace buffer, you can
1201 inspect $_sdata like any other variable available to GDB. For more
1202 information, see the "Tracepoints" chapter in GDB user manual. New
1203 remote packets have been defined to support static tracepoints, see
1204 the "New remote packets" section below.
1206 * Better reconstruction of tracepoints after disconnected tracing
1208 GDB will attempt to download the original source form of tracepoint
1209 definitions when starting a trace run, and then will upload these
1210 upon reconnection to the target, resulting in a more accurate
1211 reconstruction of the tracepoints that are in use on the target.
1215 You can now exercise direct control over the ways that GDB can
1216 affect your program. For instance, you can disallow the setting of
1217 breakpoints, so that the program can run continuously (assuming
1218 non-stop mode). In addition, the "observer" variable is available
1219 to switch all of the different controls; in observer mode, GDB
1220 cannot affect the target's behavior at all, which is useful for
1221 tasks like diagnosing live systems in the field.
1223 * The new convenience variable $_thread holds the number of the
1226 * New remote packets
1230 Return the address of the Windows Thread Information Block of a given thread.
1234 In response to several of the tracepoint packets, the target may now
1235 also respond with a number of intermediate `qRelocInsn' request
1236 packets before the final result packet, to have GDB handle
1237 relocating an instruction to execute at a different address. This
1238 is particularly useful for stubs that support fast tracepoints. GDB
1239 reports support for this feature in the qSupported packet.
1243 List static tracepoint markers in the target program.
1247 List static tracepoint markers at a given address in the target
1250 qXfer:statictrace:read
1252 Read the static trace data collected (by a `collect $_sdata'
1253 tracepoint action). The remote stub reports support for this packet
1254 to gdb's qSupported query.
1258 Send the current settings of GDB's permission flags.
1262 Send part of the source (textual) form of a tracepoint definition,
1263 which includes location, conditional, and action list.
1265 * The source command now accepts a -s option to force searching for the
1266 script in the source search path even if the script name specifies
1269 * New features in the GDB remote stub, GDBserver
1271 - GDBserver now support tracepoints (including fast tracepoints, and
1272 static tracepoints). The feature is currently supported by the
1273 i386-linux and amd64-linux builds. See the "Tracepoints support
1274 in gdbserver" section in the manual for more information.
1276 GDBserver JIT compiles the tracepoint's conditional agent
1277 expression bytecode into native code whenever possible for low
1278 overhead dynamic tracepoints conditionals. For such tracepoints,
1279 an expression that examines program state is evaluated when the
1280 tracepoint is reached, in order to determine whether to capture
1281 trace data. If the condition is simple and false, processing the
1282 tracepoint finishes very quickly and no data is gathered.
1284 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1285 for static tracepoints support.
1287 - GDBserver now supports x86_64 Windows 64-bit debugging.
1289 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1290 it understands register description.
1292 * The --batch flag now disables pagination and queries.
1294 * X86 general purpose registers
1296 GDB now supports reading/writing byte, word and double-word x86
1297 general purpose registers directly. This means you can use, say,
1298 $ah or $ax to refer, respectively, to the byte register AH and
1299 16-bit word register AX that are actually portions of the 32-bit
1300 register EAX or 64-bit register RAX.
1302 * The `commands' command now accepts a range of breakpoints to modify.
1303 A plain `commands' following a command that creates multiple
1304 breakpoints affects all the breakpoints set by that command. This
1305 applies to breakpoints set by `rbreak', and also applies when a
1306 single `break' command creates multiple breakpoints (e.g.,
1307 breakpoints on overloaded c++ functions).
1309 * The `rbreak' command now accepts a filename specification as part of
1310 its argument, limiting the functions selected by the regex to those
1311 in the specified file.
1313 * Support for remote debugging Windows and SymbianOS shared libraries
1314 from Unix hosts has been improved. Non Windows GDB builds now can
1315 understand target reported file names that follow MS-DOS based file
1316 system semantics, such as file names that include drive letters and
1317 use the backslash character as directory separator. This makes it
1318 possible to transparently use the "set sysroot" and "set
1319 solib-search-path" on Unix hosts to point as host copies of the
1320 target's shared libraries. See the new command "set
1321 target-file-system-kind" described below, and the "Commands to
1322 specify files" section in the user manual for more information.
1326 eval template, expressions...
1327 Convert the values of one or more expressions under the control
1328 of the string template to a command line, and call it.
1330 set target-file-system-kind unix|dos-based|auto
1331 show target-file-system-kind
1332 Set or show the assumed file system kind for target reported file
1335 save breakpoints <filename>
1336 Save all current breakpoint definitions to a file suitable for use
1337 in a later debugging session. To read the saved breakpoint
1338 definitions, use the `source' command.
1340 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1343 info static-tracepoint-markers
1344 Display information about static tracepoint markers in the target.
1346 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1347 Define a static tracepoint by probing a marker at the given
1348 function, line, address, or marker ID.
1352 Enable and disable observer mode.
1354 set may-write-registers on|off
1355 set may-write-memory on|off
1356 set may-insert-breakpoints on|off
1357 set may-insert-tracepoints on|off
1358 set may-insert-fast-tracepoints on|off
1359 set may-interrupt on|off
1360 Set individual permissions for GDB effects on the target. Note that
1361 some of these settings can have undesirable or surprising
1362 consequences, particularly when changed in the middle of a session.
1363 For instance, disabling the writing of memory can prevent
1364 breakpoints from being inserted, cause single-stepping to fail, or
1365 even crash your program, if you disable after breakpoints have been
1366 inserted. However, GDB should not crash.
1368 set record memory-query on|off
1369 show record memory-query
1370 Control whether to stop the inferior if memory changes caused
1371 by an instruction cannot be recorded.
1376 The disassemble command now supports "start,+length" form of two arguments.
1380 ** GDB now provides a new directory location, called the python directory,
1381 where Python scripts written for GDB can be installed. The location
1382 of that directory is <data-directory>/python, where <data-directory>
1383 is the GDB data directory. For more details, see section `Scripting
1384 GDB using Python' in the manual.
1386 ** The GDB Python API now has access to breakpoints, symbols, symbol
1387 tables, program spaces, inferiors, threads and frame's code blocks.
1388 Additionally, GDB Parameters can now be created from the API, and
1389 manipulated via set/show in the CLI.
1391 ** New functions gdb.target_charset, gdb.target_wide_charset,
1392 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1394 ** New exception gdb.GdbError.
1396 ** Pretty-printers are now also looked up in the current program space.
1398 ** Pretty-printers can now be individually enabled and disabled.
1400 ** GDB now looks for names of Python scripts to auto-load in a
1401 special section named `.debug_gdb_scripts', in addition to looking
1402 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1404 * Tracepoint actions were unified with breakpoint commands. In particular,
1405 there are no longer differences in "info break" output for breakpoints and
1406 tracepoints and the "commands" command can be used for both tracepoints and
1407 regular breakpoints.
1411 ARM Symbian arm*-*-symbianelf*
1413 * D language support.
1414 GDB now supports debugging programs written in the D programming
1417 * GDB now supports the extended ptrace interface for PowerPC which is
1418 available since Linux kernel version 2.6.34. This automatically enables
1419 any hardware breakpoints and additional hardware watchpoints available in
1420 the processor. The old ptrace interface exposes just one hardware
1421 watchpoint and no hardware breakpoints.
1423 * GDB is now able to use the Data Value Compare (DVC) register available on
1424 embedded PowerPC processors to implement in hardware simple watchpoint
1425 conditions of the form:
1427 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1429 This works in native GDB running on Linux kernels with the extended ptrace
1430 interface mentioned above.
1432 *** Changes in GDB 7.1
1436 ** Namespace Support
1438 GDB now supports importing of namespaces in C++. This enables the
1439 user to inspect variables from imported namespaces. Support for
1440 namepace aliasing has also been added. So, if a namespace is
1441 aliased in the current scope (e.g. namepace C=A; ) the user can
1442 print variables using the alias (e.g. (gdb) print C::x).
1446 All known bugs relating to the printing of virtual base class were
1447 fixed. It is now possible to call overloaded static methods using a
1452 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1453 and reinterpret_cast<> are now handled by the C++ expression parser.
1457 Xilinx MicroBlaze microblaze-*-*
1462 Xilinx MicroBlaze microblaze
1465 * Multi-program debugging.
1467 GDB now has support for multi-program (a.k.a. multi-executable or
1468 multi-exec) debugging. This allows for debugging multiple inferiors
1469 simultaneously each running a different program under the same GDB
1470 session. See "Debugging Multiple Inferiors and Programs" in the
1471 manual for more information. This implied some user visible changes
1472 in the multi-inferior support. For example, "info inferiors" now
1473 lists inferiors that are not running yet or that have exited
1474 already. See also "New commands" and "New options" below.
1476 * New tracing features
1478 GDB's tracepoint facility now includes several new features:
1480 ** Trace state variables
1482 GDB tracepoints now include support for trace state variables, which
1483 are variables managed by the target agent during a tracing
1484 experiment. They are useful for tracepoints that trigger each
1485 other, so for instance one tracepoint can count hits in a variable,
1486 and then a second tracepoint has a condition that is true when the
1487 count reaches a particular value. Trace state variables share the
1488 $-syntax of GDB convenience variables, and can appear in both
1489 tracepoint actions and condition expressions. Use the "tvariable"
1490 command to create, and "info tvariables" to view; see "Trace State
1491 Variables" in the manual for more detail.
1495 GDB now includes an option for defining fast tracepoints, which
1496 targets may implement more efficiently, such as by installing a jump
1497 into the target agent rather than a trap instruction. The resulting
1498 speedup can be by two orders of magnitude or more, although the
1499 tradeoff is that some program locations on some target architectures
1500 might not allow fast tracepoint installation, for instance if the
1501 instruction to be replaced is shorter than the jump. To request a
1502 fast tracepoint, use the "ftrace" command, with syntax identical to
1503 the regular trace command.
1505 ** Disconnected tracing
1507 It is now possible to detach GDB from the target while it is running
1508 a trace experiment, then reconnect later to see how the experiment
1509 is going. In addition, a new variable disconnected-tracing lets you
1510 tell the target agent whether to continue running a trace if the
1511 connection is lost unexpectedly.
1515 GDB now has the ability to save the trace buffer into a file, and
1516 then use that file as a target, similarly to you can do with
1517 corefiles. You can select trace frames, print data that was
1518 collected in them, and use tstatus to display the state of the
1519 tracing run at the moment that it was saved. To create a trace
1520 file, use "tsave <filename>", and to use it, do "target tfile
1523 ** Circular trace buffer
1525 You can ask the target agent to handle the trace buffer as a
1526 circular buffer, discarding the oldest trace frames to make room for
1527 newer ones, by setting circular-trace-buffer to on. This feature may
1528 not be available for all target agents.
1533 The disassemble command, when invoked with two arguments, now requires
1534 the arguments to be comma-separated.
1537 The info variables command now displays variable definitions. Files
1538 which only declare a variable are not shown.
1541 The source command is now capable of sourcing Python scripts.
1542 This feature is dependent on the debugger being build with Python
1545 Related to this enhancement is also the introduction of a new command
1546 "set script-extension" (see below).
1548 * New commands (for set/show, see "New options" below)
1550 record save [<FILENAME>]
1551 Save a file (in core file format) containing the process record
1552 execution log for replay debugging at a later time.
1554 record restore <FILENAME>
1555 Restore the process record execution log that was saved at an
1556 earlier time, for replay debugging.
1558 add-inferior [-copies <N>] [-exec <FILENAME>]
1561 clone-inferior [-copies <N>] [ID]
1562 Make a new inferior ready to execute the same program another
1563 inferior has loaded.
1568 maint info program-spaces
1569 List the program spaces loaded into GDB.
1571 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1572 show remote interrupt-sequence
1573 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1574 as the sequence to the remote target in order to interrupt the execution.
1575 Ctrl-C is a default. Some system prefers BREAK which is high level of
1576 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1577 Magic SysRq g. It is BREAK signal and character 'g'.
1579 set remote interrupt-on-connect [on | off]
1580 show remote interrupt-on-connect
1581 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1582 remote target when gdb connects to it. This is needed when you debug
1585 set remotebreak [on | off]
1587 Deprecated. Use "set/show remote interrupt-sequence" instead.
1589 tvariable $NAME [ = EXP ]
1590 Create or modify a trace state variable.
1593 List trace state variables and their values.
1595 delete tvariable $NAME ...
1596 Delete one or more trace state variables.
1599 Evaluate the given expressions without collecting anything into the
1600 trace buffer. (Valid in tracepoint actions only.)
1602 ftrace FN / FILE:LINE / *ADDR
1603 Define a fast tracepoint at the given function, line, or address.
1605 * New expression syntax
1607 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1608 GDB now parses 0b101010 identically with 42.
1612 set follow-exec-mode new|same
1613 show follow-exec-mode
1614 Control whether GDB reuses the same inferior across an exec call or
1615 creates a new one. This is useful to be able to restart the old
1616 executable after the inferior having done an exec call.
1618 set default-collect EXPR, ...
1619 show default-collect
1620 Define a list of expressions to be collected at each tracepoint.
1621 This is a useful way to ensure essential items are not overlooked,
1622 such as registers or a critical global variable.
1624 set disconnected-tracing
1625 show disconnected-tracing
1626 If set to 1, the target is instructed to continue tracing if it
1627 loses its connection to GDB. If 0, the target is to stop tracing
1630 set circular-trace-buffer
1631 show circular-trace-buffer
1632 If set to on, the target is instructed to use a circular trace buffer
1633 and discard the oldest trace frames instead of stopping the trace due
1634 to a full trace buffer. If set to off, the trace stops when the buffer
1635 fills up. Some targets may not support this.
1637 set script-extension off|soft|strict
1638 show script-extension
1639 If set to "off", the debugger does not perform any script language
1640 recognition, and all sourced files are assumed to be GDB scripts.
1641 If set to "soft" (the default), files are sourced according to
1642 filename extension, falling back to GDB scripts if the first
1644 If set to "strict", files are sourced according to filename extension.
1646 set ada trust-PAD-over-XVS on|off
1647 show ada trust-PAD-over-XVS
1648 If off, activate a workaround against a bug in the debugging information
1649 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1650 the GCC sources for more information about the GNAT encoding and
1651 PAD types in particular). It is always safe to set this option to
1652 off, but this introduces a slight performance penalty. The default
1655 * Python API Improvements
1657 ** GDB provides the new class gdb.LazyString. This is useful in
1658 some pretty-printing cases. The new method gdb.Value.lazy_string
1659 provides a simple way to create objects of this type.
1661 ** The fields returned by gdb.Type.fields now have an
1662 `is_base_class' attribute.
1664 ** The new method gdb.Type.range returns the range of an array type.
1666 ** The new method gdb.parse_and_eval can be used to parse and
1667 evaluate an expression.
1669 * New remote packets
1672 Define a trace state variable.
1675 Get the current value of a trace state variable.
1678 Set desired tracing behavior upon disconnection.
1681 Set the trace buffer to be linear or circular.
1684 Get data about the tracepoints currently in use.
1688 Process record now works correctly with hardware watchpoints.
1690 Multiple bug fixes have been made to the mips-irix port, making it
1691 much more reliable. In particular:
1692 - Debugging threaded applications is now possible again. Previously,
1693 GDB would hang while starting the program, or while waiting for
1694 the program to stop at a breakpoint.
1695 - Attaching to a running process no longer hangs.
1696 - An error occurring while loading a core file has been fixed.
1697 - Changing the value of the PC register now works again. This fixes
1698 problems observed when using the "jump" command, or when calling
1699 a function from GDB, or even when assigning a new value to $pc.
1700 - With the "finish" and "return" commands, the return value for functions
1701 returning a small array is now correctly printed.
1702 - It is now possible to break on shared library code which gets executed
1703 during a shared library init phase (code executed while executing
1704 their .init section). Previously, the breakpoint would have no effect.
1705 - GDB is now able to backtrace through the signal handler for
1706 non-threaded programs.
1708 PIE (Position Independent Executable) programs debugging is now supported.
1709 This includes debugging execution of PIC (Position Independent Code) shared
1710 libraries although for that, it should be possible to run such libraries as an
1713 *** Changes in GDB 7.0
1715 * GDB now has an interface for JIT compilation. Applications that
1716 dynamically generate code can create symbol files in memory and register
1717 them with GDB. For users, the feature should work transparently, and
1718 for JIT developers, the interface is documented in the GDB manual in the
1719 "JIT Compilation Interface" chapter.
1721 * Tracepoints may now be conditional. The syntax is as for
1722 breakpoints; either an "if" clause appended to the "trace" command,
1723 or the "condition" command is available. GDB sends the condition to
1724 the target for evaluation using the same bytecode format as is used
1725 for tracepoint actions.
1727 * The disassemble command now supports: an optional /r modifier, print the
1728 raw instructions in hex as well as in symbolic form, and an optional /m
1729 modifier to print mixed source+assembly.
1731 * Process record and replay
1733 In a architecture environment that supports ``process record and
1734 replay'', ``process record and replay'' target can record a log of
1735 the process execution, and replay it with both forward and reverse
1738 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1739 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1740 set execution-direction {forward|reverse}, for targets that support
1743 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1744 feature is available with a native GDB running on kernel version
1747 * GDB now has support for multi-byte and wide character sets on the
1748 target. Strings whose character type is wchar_t, char16_t, or
1749 char32_t are now correctly printed. GDB supports wide- and unicode-
1750 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1751 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1752 `printf'. This feature requires iconv to work properly; if your
1753 system does not have a working iconv, GDB can use GNU libiconv. See
1754 the installation instructions for more information.
1756 * GDB now supports automatic retrieval of shared library files from
1757 remote targets. To use this feature, specify a system root that begins
1758 with the `remote:' prefix, either via the `set sysroot' command or via
1759 the `--with-sysroot' configure-time option.
1761 * "info sharedlibrary" now takes an optional regex of libraries to show,
1762 and it now reports if a shared library has no debugging information.
1764 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1765 now complete on file names.
1767 * When completing in expressions, gdb will attempt to limit
1768 completions to allowable structure or union fields, where appropriate.
1769 For instance, consider:
1771 # struct example { int f1; double f2; };
1772 # struct example variable;
1775 If the user types TAB at the end of this command line, the available
1776 completions will be "f1" and "f2".
1778 * Inlined functions are now supported. They show up in backtraces, and
1779 the "step", "next", and "finish" commands handle them automatically.
1781 * GDB now supports the token-splicing (##) and stringification (#)
1782 operators when expanding macros. It also supports variable-arity
1785 * GDB now supports inspecting extra signal information, exported by
1786 the new $_siginfo convenience variable. The feature is currently
1787 implemented on linux ARM, i386 and amd64.
1789 * GDB can now display the VFP floating point registers and NEON vector
1790 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1791 can provide these registers (requires Linux 2.6.30 or later). Remote
1792 and simulator targets may also provide them.
1794 * New remote packets
1797 Search memory for a sequence of bytes.
1800 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1801 operation over reliable transport links. Use of this packet is
1802 controlled by the `set remote noack-packet' command.
1805 Kill the process with the specified process ID. Use this in preference
1806 to `k' when multiprocess protocol extensions are supported.
1809 Obtains additional operating system information
1813 Read or write additional signal information.
1815 * Removed remote protocol undocumented extension
1817 An undocumented extension to the remote protocol's `S' stop reply
1818 packet that permited the stub to pass a process id was removed.
1819 Remote servers should use the `T' stop reply packet instead.
1821 * GDB now supports multiple function calling conventions according to the
1822 DWARF-2 DW_AT_calling_convention function attribute.
1824 * The SH target utilizes the aforementioned change to distinguish between gcc
1825 and Renesas calling convention. It also adds the new CLI commands
1826 `set/show sh calling-convention'.
1828 * GDB can now read compressed debug sections, as produced by GNU gold
1829 with the --compress-debug-sections=zlib flag.
1831 * 64-bit core files are now supported on AIX.
1833 * Thread switching is now supported on Tru64.
1835 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1836 which will be allocated using malloc later in program execution.
1838 * The qXfer:libraries:read remote procotol packet now allows passing a
1839 list of section offsets.
1841 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1842 conditions handling signals delivered during attach or thread creation
1843 have also been fixed.
1845 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1846 From the user's standpoint, all unqualified instances of True and False
1847 are treated as the standard definitions, regardless of context.
1849 * GDB now parses C++ symbol and type names more flexibly. For
1852 template<typename T> class C { };
1855 GDB will now correctly handle all of:
1857 ptype C<char const *>
1858 ptype C<char const*>
1859 ptype C<const char *>
1860 ptype C<const char*>
1862 * New features in the GDB remote stub, gdbserver
1864 - The "--wrapper" command-line argument tells gdbserver to use a
1865 wrapper program to launch programs for debugging.
1867 - On PowerPC and S/390 targets, it is now possible to use a single
1868 gdbserver executable to debug both 32-bit and 64-bit programs.
1869 (This requires gdbserver itself to be built as a 64-bit executable.)
1871 - gdbserver uses the new noack protocol mode for TCP connections to
1872 reduce communications latency, if also supported and enabled in GDB.
1874 - Support for the sparc64-linux-gnu target is now included in
1877 - The amd64-linux build of gdbserver now supports debugging both
1878 32-bit and 64-bit programs.
1880 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1881 now support hardware watchpoints, and will use them automatically
1886 GDB now has support for scripting using Python. Whether this is
1887 available is determined at configure time.
1889 New GDB commands can now be written in Python.
1891 * Ada tasking support
1893 Ada tasks can now be inspected in GDB. The following commands have
1897 Print the list of Ada tasks.
1899 Print detailed information about task number N.
1901 Print the task number of the current task.
1903 Switch the context of debugging to task number N.
1905 * Support for user-defined prefixed commands. The "define" command can
1906 add new commands to existing prefixes, e.g. "target".
1908 * Multi-inferior, multi-process debugging.
1910 GDB now has generalized support for multi-inferior debugging. See
1911 "Debugging Multiple Inferiors" in the manual for more information.
1912 Although availability still depends on target support, the command
1913 set is more uniform now. The GNU/Linux specific multi-forks support
1914 has been migrated to this new framework. This implied some user
1915 visible changes; see "New commands" and also "Removed commands"
1918 * Target descriptions can now describe the target OS ABI. See the
1919 "Target Description Format" section in the user manual for more
1922 * Target descriptions can now describe "compatible" architectures
1923 to indicate that the target can execute applications for a different
1924 architecture in addition to those for the main target architecture.
1925 See the "Target Description Format" section in the user manual for
1928 * Multi-architecture debugging.
1930 GDB now includes general supports for debugging applications on
1931 hybrid systems that use more than one single processor architecture
1932 at the same time. Each such hybrid architecture still requires
1933 specific support to be added. The only hybrid architecture supported
1934 in this version of GDB is the Cell Broadband Engine.
1936 * GDB now supports integrated debugging of Cell/B.E. applications that
1937 use both the PPU and SPU architectures. To enable support for hybrid
1938 Cell/B.E. debugging, you need to configure GDB to support both the
1939 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1940 --enable-targets configure option.
1942 * Non-stop mode debugging.
1944 For some targets, GDB now supports an optional mode of operation in
1945 which you can examine stopped threads while other threads continue
1946 to execute freely. This is referred to as non-stop mode, with the
1947 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1948 section in the user manual for more information.
1950 To be able to support remote non-stop debugging, a remote stub needs
1951 to implement the non-stop mode remote protocol extensions, as
1952 described in the "Remote Non-Stop" section of the user manual. The
1953 GDB remote stub, gdbserver, has been adjusted to support these
1954 extensions on linux targets.
1956 * New commands (for set/show, see "New options" below)
1958 catch syscall [NAME(S) | NUMBER(S)]
1959 Catch system calls. Arguments, which should be names of system
1960 calls or their numbers, mean catch only those syscalls. Without
1961 arguments, every syscall will be caught. When the inferior issues
1962 any of the specified syscalls, GDB will stop and announce the system
1963 call, both when it is called and when its call returns. This
1964 feature is currently available with a native GDB running on the
1965 Linux Kernel, under the following architectures: x86, x86_64,
1966 PowerPC and PowerPC64.
1968 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1970 Search memory for a sequence of bytes.
1972 maint set python print-stack
1973 maint show python print-stack
1974 Show a stack trace when an error is encountered in a Python script.
1977 Invoke CODE by passing it to the Python interpreter.
1982 These allow macros to be defined, undefined, and listed
1986 Show operating system information about processes.
1989 List the inferiors currently under GDB's control.
1992 Switch focus to inferior number NUM.
1995 Detach from inferior number NUM.
1998 Kill inferior number NUM.
2002 set spu stop-on-load
2003 show spu stop-on-load
2004 Control whether to stop for new SPE threads during Cell/B.E. debugging.
2006 set spu auto-flush-cache
2007 show spu auto-flush-cache
2008 Control whether to automatically flush the software-managed cache
2009 during Cell/B.E. debugging.
2011 set sh calling-convention
2012 show sh calling-convention
2013 Control the calling convention used when calling SH target functions.
2016 show debug timestamp
2017 Control display of timestamps with GDB debugging output.
2019 set disassemble-next-line
2020 show disassemble-next-line
2021 Control display of disassembled source lines or instructions when
2024 set remote noack-packet
2025 show remote noack-packet
2026 Set/show the use of remote protocol QStartNoAckMode packet. See above
2027 under "New remote packets."
2029 set remote query-attached-packet
2030 show remote query-attached-packet
2031 Control use of remote protocol `qAttached' (query-attached) packet.
2033 set remote read-siginfo-object
2034 show remote read-siginfo-object
2035 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2038 set remote write-siginfo-object
2039 show remote write-siginfo-object
2040 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2043 set remote reverse-continue
2044 show remote reverse-continue
2045 Control use of remote protocol 'bc' (reverse-continue) packet.
2047 set remote reverse-step
2048 show remote reverse-step
2049 Control use of remote protocol 'bs' (reverse-step) packet.
2051 set displaced-stepping
2052 show displaced-stepping
2053 Control displaced stepping mode. Displaced stepping is a way to
2054 single-step over breakpoints without removing them from the debuggee.
2055 Also known as "out-of-line single-stepping".
2058 show debug displaced
2059 Control display of debugging info for displaced stepping.
2061 maint set internal-error
2062 maint show internal-error
2063 Control what GDB does when an internal error is detected.
2065 maint set internal-warning
2066 maint show internal-warning
2067 Control what GDB does when an internal warning is detected.
2072 Use a wrapper program to launch programs for debugging.
2074 set multiple-symbols (all|ask|cancel)
2075 show multiple-symbols
2076 The value of this variable can be changed to adjust the debugger behavior
2077 when an expression or a breakpoint location contains an ambiguous symbol
2078 name (an overloaded function name, for instance).
2080 set breakpoint always-inserted
2081 show breakpoint always-inserted
2082 Keep breakpoints always inserted in the target, as opposed to inserting
2083 them when resuming the target, and removing them when the target stops.
2084 This option can improve debugger performance on slow remote targets.
2086 set arm fallback-mode (arm|thumb|auto)
2087 show arm fallback-mode
2088 set arm force-mode (arm|thumb|auto)
2090 These commands control how ARM GDB determines whether instructions
2091 are ARM or Thumb. The default for both settings is auto, which uses
2092 the current CPSR value for instructions without symbols; previous
2093 versions of GDB behaved as if "set arm fallback-mode arm".
2095 set disable-randomization
2096 show disable-randomization
2097 Standalone programs run with the virtual address space randomization enabled
2098 by default on some platforms. This option keeps the addresses stable across
2099 multiple debugging sessions.
2103 Control whether other threads are stopped or not when some thread hits
2108 Requests that asynchronous execution is enabled in the target, if available.
2109 In this case, it's possible to resume target in the background, and interact
2110 with GDB while the target is running. "show target-async" displays the
2111 current state of asynchronous execution of the target.
2113 set target-wide-charset
2114 show target-wide-charset
2115 The target-wide-charset is the name of the character set that GDB
2116 uses when printing characters whose type is wchar_t.
2118 set tcp auto-retry (on|off)
2120 set tcp connect-timeout
2121 show tcp connect-timeout
2122 These commands allow GDB to retry failed TCP connections to a remote stub
2123 with a specified timeout period; this is useful if the stub is launched
2124 in parallel with GDB but may not be ready to accept connections immediately.
2126 set libthread-db-search-path
2127 show libthread-db-search-path
2128 Control list of directories which GDB will search for appropriate
2131 set schedule-multiple (on|off)
2132 show schedule-multiple
2133 Allow GDB to resume all threads of all processes or only threads of
2134 the current process.
2138 Use more aggressive caching for accesses to the stack. This improves
2139 performance of remote debugging (particularly backtraces) without
2140 affecting correctness.
2142 set interactive-mode (on|off|auto)
2143 show interactive-mode
2144 Control whether GDB runs in interactive mode (on) or not (off).
2145 When in interactive mode, GDB waits for the user to answer all
2146 queries. Otherwise, GDB does not wait and assumes the default
2147 answer. When set to auto (the default), GDB determines which
2148 mode to use based on the stdin settings.
2153 For program forks, this is replaced by the new more generic `info
2154 inferiors' command. To list checkpoints, you can still use the
2155 `info checkpoints' command, which was an alias for the `info forks'
2159 Replaced by the new `inferior' command. To switch between
2160 checkpoints, you can still use the `restart' command, which was an
2161 alias for the `fork' command.
2164 This is removed, since some targets don't have a notion of
2165 processes. To switch between processes, you can still use the
2166 `inferior' command using GDB's own inferior number.
2169 For program forks, this is replaced by the new more generic `kill
2170 inferior' command. To delete a checkpoint, you can still use the
2171 `delete checkpoint' command, which was an alias for the `delete
2175 For program forks, this is replaced by the new more generic `detach
2176 inferior' command. To detach a checkpoint, you can still use the
2177 `detach checkpoint' command, which was an alias for the `detach
2180 * New native configurations
2182 x86/x86_64 Darwin i[34567]86-*-darwin*
2184 x86_64 MinGW x86_64-*-mingw*
2188 Lattice Mico32 lm32-*
2189 x86 DICOS i[34567]86-*-dicos*
2190 x86_64 DICOS x86_64-*-dicos*
2193 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2194 (mingw32ce) debugging.
2200 These commands were actually not implemented on any target.
2202 *** Changes in GDB 6.8
2204 * New native configurations
2206 NetBSD/hppa hppa*-*netbsd*
2207 Xtensa GNU/Linux xtensa*-*-linux*
2211 NetBSD/hppa hppa*-*-netbsd*
2212 Xtensa GNU/Lunux xtensa*-*-linux*
2214 * Change in command line behavior -- corefiles vs. process ids.
2216 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2217 attaching to process NUMBER fails, GDB no longer attempts to open a
2218 core file named NUMBER. Attaching to a program using the -c option
2219 is no longer supported. Instead, use the '-p' or '--pid' options.
2221 * GDB can now be built as a native debugger for debugging Windows x86
2222 (mingw32) Portable Executable (PE) programs.
2224 * Pending breakpoints no longer change their number when their address
2227 * GDB now supports breakpoints with multiple locations,
2228 including breakpoints on C++ constructors, inside C++ templates,
2229 and in inlined functions.
2231 * GDB's ability to debug optimized code has been improved. GDB more
2232 accurately identifies function bodies and lexical blocks that occupy
2233 more than one contiguous range of addresses.
2235 * Target descriptions can now describe registers for PowerPC.
2237 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2238 registers on PowerPC targets.
2240 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2241 targets even when the libthread_db library is not available.
2243 * The GDB remote stub, gdbserver, now supports the new file transfer
2244 commands (remote put, remote get, and remote delete).
2246 * The GDB remote stub, gdbserver, now supports run and attach in
2247 extended-remote mode.
2249 * hppa*64*-*-hpux11* target broken
2250 The debugger is unable to start a program and fails with the following
2251 error: "Error trying to get information about dynamic linker".
2252 The gdb-6.7 release is also affected.
2254 * GDB now supports the --enable-targets= configure option to allow
2255 building a single GDB executable that supports multiple remote
2256 target architectures.
2258 * GDB now supports debugging C and C++ programs which use the
2259 Decimal Floating Point extension. In addition, the PowerPC target
2260 now has a set of pseudo-registers to inspect decimal float values
2261 stored in two consecutive float registers.
2263 * The -break-insert MI command can optionally create pending
2266 * Improved support for debugging Ada
2267 Many improvements to the Ada language support have been made. These
2269 - Better support for Ada2005 interface types
2270 - Improved handling of arrays and slices in general
2271 - Better support for Taft-amendment types
2272 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2274 - Improved command completion in Ada
2277 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2282 set print frame-arguments (all|scalars|none)
2283 show print frame-arguments
2284 The value of this variable can be changed to control which argument
2285 values should be printed by the debugger when displaying a frame.
2290 Transfer files to and from a remote target, and delete remote files.
2297 Transfer files to and from a remote target, and delete remote files.
2299 * New remote packets
2306 Open, close, read, write, and delete files on the remote system.
2309 Attach to an existing process on the remote system, in extended-remote
2313 Run a new process on the remote system, in extended-remote mode.
2315 *** Changes in GDB 6.7
2317 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2318 bfd, libiberty and opcodes, as revealed by static analysis donated by
2319 Coverity, Inc. (http://scan.coverity.com).
2321 * When looking up multiply-defined global symbols, GDB will now prefer the
2322 symbol definition in the current shared library if it was built using the
2323 -Bsymbolic linker option.
2325 * When the Text User Interface (TUI) is not configured, GDB will now
2326 recognize the -tui command-line option and print a message that the TUI
2329 * The GDB remote stub, gdbserver, now has lower overhead for high
2330 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2332 * GDB for MIPS targets now autodetects whether a remote target provides
2333 32-bit or 64-bit register values.
2335 * Support for C++ member pointers has been improved.
2337 * GDB now understands XML target descriptions, which specify the
2338 target's overall architecture. GDB can read a description from
2339 a local file or over the remote serial protocol.
2341 * Vectors of single-byte data use a new integer type which is not
2342 automatically displayed as character or string data.
2344 * The /s format now works with the print command. It displays
2345 arrays of single-byte integers and pointers to single-byte integers
2348 * Target descriptions can now describe target-specific registers,
2349 for architectures which have implemented the support (currently
2350 only ARM, M68K, and MIPS).
2352 * GDB and the GDB remote stub, gdbserver, now support the XScale
2355 * The GDB remote stub, gdbserver, has been updated to support
2356 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2357 has been rewritten to use the standard GDB remote protocol.
2359 * GDB can now step into C++ functions which are called through thunks.
2361 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2363 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2364 layout. It also supports a TextSeg= and DataSeg= response when only
2365 segment base addresses (rather than offsets) are available.
2367 * The /i format now outputs any trailing branch delay slot instructions
2368 immediately following the last instruction within the count specified.
2370 * The GDB remote protocol "T" stop reply packet now supports a
2371 "library" response. Combined with the new "qXfer:libraries:read"
2372 packet, this response allows GDB to debug shared libraries on targets
2373 where the operating system manages the list of loaded libraries (e.g.
2374 Windows and SymbianOS).
2376 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2377 (DLLs) on Windows and Windows CE targets.
2379 * GDB now supports a faster verification that a .debug file matches its binary
2380 according to its build-id signature, if the signature is present.
2386 Enable or disable hardware flow control (RTS/CTS) on the serial port
2387 when debugging using remote targets.
2389 set mem inaccessible-by-default
2390 show mem inaccessible-by-default
2391 If the target supplies a memory map, for instance via the remote
2392 protocol's "qXfer:memory-map:read" packet, setting this variable
2393 prevents GDB from accessing memory outside the memory map. This
2394 is useful for targets with memory mapped registers or which react
2395 badly to accesses of unmapped address space.
2397 set breakpoint auto-hw
2398 show breakpoint auto-hw
2399 If the target supplies a memory map, for instance via the remote
2400 protocol's "qXfer:memory-map:read" packet, setting this variable
2401 lets GDB use hardware breakpoints automatically for memory regions
2402 where it can not use software breakpoints. This covers both the
2403 "break" command and internal breakpoints used for other commands
2404 including "next" and "finish".
2407 catch exception unhandled
2408 Stop the program execution when Ada exceptions are raised.
2411 Stop the program execution when an Ada assertion failed.
2415 Set an alternate system root for target files. This is a more
2416 general version of "set solib-absolute-prefix", which is now
2417 an alias to "set sysroot".
2420 Provide extended SPU facility status information. This set of
2421 commands is available only when debugging the Cell/B.E. SPU
2424 * New native configurations
2426 OpenBSD/sh sh*-*openbsd*
2429 unset tdesc filename
2431 Use the specified local file as an XML target description, and do
2432 not query the target for its built-in description.
2436 OpenBSD/sh sh*-*-openbsd*
2437 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2438 Toshiba Media Processor mep-elf
2440 * New remote packets
2443 Ignore the specified signals; pass them directly to the debugged program
2444 without stopping other threads or reporting them to GDB.
2446 qXfer:features:read:
2447 Read an XML target description from the target, which describes its
2452 Read or write contents of an spufs file on the target system. These
2453 packets are available only on the Cell/B.E. SPU architecture.
2455 qXfer:libraries:read:
2456 Report the loaded shared libraries. Combined with new "T" packet
2457 response, this packet allows GDB to debug shared libraries on
2458 targets where the operating system manages the list of loaded
2459 libraries (e.g. Windows and SymbianOS).
2463 Support for these obsolete configurations has been removed.
2471 i[34567]86-*-lynxos*
2472 i[34567]86-*-netware*
2473 i[34567]86-*-sco3.2v5*
2474 i[34567]86-*-sco3.2v4*
2476 i[34567]86-*-sysv4.2*
2479 i[34567]86-*-unixware2*
2480 i[34567]86-*-unixware*
2489 * Other removed features
2496 Various m68k-only ROM monitors.
2503 Various Renesas ROM monitors and debugging interfaces for SH and
2508 Support for a Macraigor serial interface to on-chip debugging.
2509 GDB does not directly support the newer parallel or USB
2514 A debug information format. The predecessor to DWARF 2 and
2515 DWARF 3, which are still supported.
2517 Support for the HP aCC compiler on HP-UX/PA-RISC
2519 SOM-encapsulated symbolic debugging information, automatic
2520 invocation of pxdb, and the aCC custom C++ ABI. This does not
2521 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2522 with aCC can still be debugged on an assembly level.
2524 MIPS ".pdr" sections
2526 A MIPS-specific format used to describe stack frame layout
2527 in debugging information.
2531 GDB could work with an older version of Guile to debug
2532 the interpreter and Scheme programs running in it.
2534 set mips stack-arg-size
2535 set mips saved-gpreg-size
2537 Use "set mips abi" to control parameter passing for MIPS.
2539 *** Changes in GDB 6.6
2544 Cell Broadband Engine SPU spu-elf
2546 * GDB can now be configured as a cross-debugger targeting native Windows
2547 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2548 running on a Windows system over TCP/IP to debug Windows programs.
2550 * The GDB remote stub, gdbserver, has been updated to support Windows and
2551 Cygwin debugging. Both single-threaded and multi-threaded programs are
2554 * The "set trust-readonly-sections" command works again. This command was
2555 broken in GDB 6.3, 6.4, and 6.5.
2557 * The "load" command now supports writing to flash memory, if the remote
2558 stub provides the required support.
2560 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2561 longer requires symbolic debug information (e.g. DWARF-2).
2566 unset substitute-path
2567 show substitute-path
2568 Manage a list of substitution rules that GDB uses to rewrite the name
2569 of the directories where the sources are located. This can be useful
2570 for instance when the sources were moved to a different location
2571 between compilation and debugging.
2575 Print each CLI command as it is executed. Each command is prefixed with
2576 a number of `+' symbols representing the nesting depth.
2577 The source command now has a `-v' option to enable the same feature.
2581 The ARM Demon monitor support (RDP protocol, "target rdp").
2583 Kernel Object Display, an embedded debugging feature which only worked with
2584 an obsolete version of Cisco IOS.
2586 The 'set download-write-size' and 'show download-write-size' commands.
2588 * New remote packets
2591 Tell a stub about GDB client features, and request remote target features.
2592 The first feature implemented is PacketSize, which allows the target to
2593 specify the size of packets it can handle - to minimize the number of
2594 packets required and improve performance when connected to a remote
2598 Fetch an OS auxilliary vector from the remote stub. This packet is a
2599 more efficient replacement for qPart:auxv:read.
2601 qXfer:memory-map:read:
2602 Fetch a memory map from the remote stub, including information about
2603 RAM, ROM, and flash memory devices.
2608 Erase and program a flash memory device.
2610 * Removed remote packets
2613 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2614 used it, and only gdbserver implemented it.
2616 *** Changes in GDB 6.5
2620 Renesas M32C/M16C m32c-elf
2622 Morpho Technologies ms1 ms1-elf
2626 init-if-undefined Initialize a convenience variable, but
2627 only if it doesn't already have a value.
2629 The following commands are presently only implemented for native GNU/Linux:
2631 checkpoint Save a snapshot of the program state.
2633 restart <n> Return the program state to a
2634 previously saved state.
2636 info checkpoints List currently saved checkpoints.
2638 delete-checkpoint <n> Delete a previously saved checkpoint.
2640 set|show detach-on-fork Tell gdb whether to detach from a newly
2641 forked process, or to keep debugging it.
2643 info forks List forks of the user program that
2644 are available to be debugged.
2646 fork <n> Switch to debugging one of several
2647 forks of the user program that are
2648 available to be debugged.
2650 delete-fork <n> Delete a fork from the list of forks
2651 that are available to be debugged (and
2652 kill the forked process).
2654 detach-fork <n> Delete a fork from the list of forks
2655 that are available to be debugged (and
2656 allow the process to continue).
2660 Morpho Technologies ms2 ms1-elf
2662 * Improved Windows host support
2664 GDB now builds as a cross debugger hosted on i686-mingw32, including
2665 native console support, and remote communications using either
2666 network sockets or serial ports.
2668 * Improved Modula-2 language support
2670 GDB can now print most types in the Modula-2 syntax. This includes:
2671 basic types, set types, record types, enumerated types, range types,
2672 pointer types and ARRAY types. Procedure var parameters are correctly
2673 printed and hexadecimal addresses and character constants are also
2674 written in the Modula-2 syntax. Best results can be obtained by using
2675 GNU Modula-2 together with the -gdwarf-2 command line option.
2679 The ARM rdi-share module.
2681 The Netware NLM debug server.
2683 *** Changes in GDB 6.4
2685 * New native configurations
2687 OpenBSD/arm arm*-*-openbsd*
2688 OpenBSD/mips64 mips64-*-openbsd*
2692 Morpho Technologies ms1 ms1-elf
2694 * New command line options
2696 --batch-silent As for --batch, but totally silent.
2697 --return-child-result The debugger will exist with the same value
2698 the child (debugged) program exited with.
2699 --eval-command COMMAND, -ex COMMAND
2700 Execute a single GDB CLI command. This may be
2701 specified multiple times and in conjunction
2702 with the --command (-x) option.
2704 * Deprecated commands removed
2706 The following commands, that were deprecated in 2000, have been
2710 set|show arm disassembly-flavor set|show arm disassembler
2711 othernames set arm disassembler
2712 set|show remotedebug set|show debug remote
2713 set|show archdebug set|show debug arch
2714 set|show eventdebug set|show debug event
2717 * New BSD user-level threads support
2719 It is now possible to debug programs using the user-level threads
2720 library on OpenBSD and FreeBSD. Currently supported (target)
2723 FreeBSD/amd64 x86_64-*-freebsd*
2724 FreeBSD/i386 i386-*-freebsd*
2725 OpenBSD/i386 i386-*-openbsd*
2727 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2728 are not yet supported.
2730 * New support for Matsushita MN10300 w/sim added
2731 (Work in progress). mn10300-elf.
2733 * REMOVED configurations and files
2735 VxWorks and the XDR protocol *-*-vxworks
2736 Motorola MCORE mcore-*-*
2737 National Semiconductor NS32000 ns32k-*-*
2739 * New "set print array-indexes" command
2741 After turning this setting "on", GDB prints the index of each element
2742 when displaying arrays. The default is "off" to preserve the previous
2745 * VAX floating point support
2747 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2749 * User-defined command support
2751 In addition to using $arg0..$arg9 for argument passing, it is now possible
2752 to use $argc to determine now many arguments have been passed. See the
2753 section on user-defined commands in the user manual for more information.
2755 *** Changes in GDB 6.3:
2757 * New command line option
2759 GDB now accepts -l followed by a number to set the timeout for remote
2762 * GDB works with GCC -feliminate-dwarf2-dups
2764 GDB now supports a more compact representation of DWARF-2 debug
2765 information using DW_FORM_ref_addr references. These are produced
2766 by GCC with the option -feliminate-dwarf2-dups and also by some
2767 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2768 to use -feliminate-dwarf2-dups.
2770 * Internationalization
2772 When supported by the host system, GDB will be built with
2773 internationalization (libintl). The task of marking up the sources is
2774 continued, we're looking forward to our first translation.
2778 Initial support for debugging programs compiled with the GNAT
2779 implementation of the Ada programming language has been integrated
2780 into GDB. In this release, support is limited to expression evaluation.
2782 * New native configurations
2784 GNU/Linux/m32r m32r-*-linux-gnu
2788 GDB's remote protocol now includes support for the 'p' packet. This
2789 packet is used to fetch individual registers from a remote inferior.
2791 * END-OF-LIFE registers[] compatibility module
2793 GDB's internal register infrastructure has been completely rewritten.
2794 The new infrastructure making possible the implementation of key new
2795 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2798 GDB 6.3 will be the last release to include the the registers[]
2799 compatibility module that allowed out-of-date configurations to
2800 continue to work. This change directly impacts the following
2810 powerpc bdm protocol
2812 Unless there is activity to revive these configurations, they will be
2813 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2815 * OBSOLETE configurations and files
2817 Configurations that have been declared obsolete in this release have
2818 been commented out. Unless there is activity to revive these
2819 configurations, the next release of GDB will have their sources
2820 permanently REMOVED.
2829 *** Changes in GDB 6.2.1:
2831 * MIPS `break main; run' gave an heuristic-fence-post warning
2833 When attempting to run even a simple program, a warning about
2834 heuristic-fence-post being hit would be reported. This problem has
2837 * MIPS IRIX 'long double' crashed GDB
2839 When examining a long double variable, GDB would get a segmentation
2840 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2841 IRIX long double values).
2845 A bug in the VAX stack code was causing problems with the "next"
2846 command. This problem has been fixed.
2848 *** Changes in GDB 6.2:
2850 * Fix for ``many threads''
2852 On GNU/Linux systems that use the NPTL threads library, a program
2853 rapidly creating and deleting threads would confuse GDB leading to the
2856 ptrace: No such process.
2857 thread_db_get_info: cannot get thread info: generic error
2859 This problem has been fixed.
2861 * "-async" and "-noasync" options removed.
2863 Support for the broken "-noasync" option has been removed (it caused
2866 * New ``start'' command.
2868 This command runs the program until the begining of the main procedure.
2870 * New BSD Kernel Data Access Library (libkvm) interface
2872 Using ``target kvm'' it is now possible to debug kernel core dumps and
2873 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2874 platforms. Currently supported (native-only) configurations are:
2876 FreeBSD/amd64 x86_64-*-freebsd*
2877 FreeBSD/i386 i?86-*-freebsd*
2878 NetBSD/i386 i?86-*-netbsd*
2879 NetBSD/m68k m68*-*-netbsd*
2880 NetBSD/sparc sparc-*-netbsd*
2881 OpenBSD/amd64 x86_64-*-openbsd*
2882 OpenBSD/i386 i?86-*-openbsd*
2883 OpenBSD/m68k m68*-openbsd*
2884 OpenBSD/sparc sparc-*-openbsd*
2886 * Signal trampoline code overhauled
2888 Many generic problems with GDB's signal handling code have been fixed.
2889 These include: backtraces through non-contiguous stacks; recognition
2890 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2891 call; backtrace through a signal trampoline; step into and out of
2892 signal handlers; and single-stepping in the signal trampoline.
2894 Please note that kernel bugs are a limiting factor here. These
2895 features have been shown to work on an s390 GNU/Linux system that
2896 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2898 * Cygwin support for DWARF 2 added.
2900 * New native configurations
2902 GNU/Linux/hppa hppa*-*-linux*
2903 OpenBSD/hppa hppa*-*-openbsd*
2904 OpenBSD/m68k m68*-*-openbsd*
2905 OpenBSD/m88k m88*-*-openbsd*
2906 OpenBSD/powerpc powerpc-*-openbsd*
2907 NetBSD/vax vax-*-netbsd*
2908 OpenBSD/vax vax-*-openbsd*
2910 * END-OF-LIFE frame compatibility module
2912 GDB's internal frame infrastructure has been completely rewritten.
2913 The new infrastructure making it possible to support key new features
2914 including DWARF 2 Call Frame Information. To aid in the task of
2915 migrating old configurations to this new infrastructure, a
2916 compatibility module, that allowed old configurations to continue to
2917 work, was also included.
2919 GDB 6.2 will be the last release to include this frame compatibility
2920 module. This change directly impacts the following configurations:
2930 Unless there is activity to revive these configurations, they will be
2931 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2933 * REMOVED configurations and files
2935 Sun 3, running SunOS 3 m68*-*-sunos3*
2936 Sun 3, running SunOS 4 m68*-*-sunos4*
2937 Sun 2, running SunOS 3 m68000-*-sunos3*
2938 Sun 2, running SunOS 4 m68000-*-sunos4*
2939 Motorola 680x0 running LynxOS m68*-*-lynxos*
2940 AT&T 3b1/Unix pc m68*-att-*
2941 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2942 decstation mips-dec-* mips-little-*
2943 riscos mips-*-riscos* mips-*-sysv*
2944 sonymips mips-sony-*
2945 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2947 *** Changes in GDB 6.1.1:
2949 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2951 The TUI (Text-mode User Interface) is now built as part of a default
2952 GDB configuration. It is enabled by either selecting the TUI with the
2953 command line option "-i=tui" or by running the separate "gdbtui"
2954 program. For more information on the TUI, see the manual "Debugging
2957 * Pending breakpoint support (also included in GDB 6.1)
2959 Support has been added to allow you to specify breakpoints in shared
2960 libraries that have not yet been loaded. If a breakpoint location
2961 cannot be found, and the "breakpoint pending" option is set to auto,
2962 GDB queries you if you wish to make the breakpoint pending on a future
2963 shared-library load. If and when GDB resolves the breakpoint symbol,
2964 the pending breakpoint is removed as one or more regular breakpoints
2967 Pending breakpoints are very useful for GCJ Java debugging.
2969 * Fixed ISO-C build problems
2971 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2972 non ISO-C code that stopped them being built using a more strict ISO-C
2973 compiler (e.g., IBM's C compiler).
2975 * Fixed build problem on IRIX 5
2977 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2978 wasn't able to compile compile on an IRIX 5 system.
2980 * Added execute permission to gdb/gdbserver/configure
2982 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2983 permission. This bug would cause configure to fail on a number of
2984 systems (Solaris, IRIX). Ref: server/519.
2986 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2988 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2989 has been updated to use constant array sizes.
2991 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2993 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2994 its generated DWARF Call Frame Info. This encoding was causing GDB to
2995 panic, that panic has been fixed. Ref: gdb/1628.
2997 * Fixed a problem when examining parameters in shared library code.
2999 When examining parameters in optimized shared library code generated
3000 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
3001 not available''. GDB now correctly displays the variable's value.
3003 *** Changes in GDB 6.1:
3005 * Removed --with-mmalloc
3007 Support for the mmalloc memory manager has been removed, as it
3008 conflicted with the internal gdb byte cache.
3010 * Changes in AMD64 configurations
3012 The AMD64 target now includes the %cs and %ss registers. As a result
3013 the AMD64 remote protocol has changed; this affects the floating-point
3014 and SSE registers. If you rely on those registers for your debugging,
3015 you should upgrade gdbserver on the remote side.
3017 * Revised SPARC target
3019 The SPARC target has been completely revised, incorporating the
3020 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3021 support for LynxOS and SunOS 4 has been dropped. Calling functions
3022 from within GDB on operating systems with a non-executable stack
3023 (Solaris, OpenBSD) now works.
3027 GDB has a new C++ demangler which does a better job on the mangled
3028 names generated by current versions of g++. It also runs faster, so
3029 with this and other changes gdb should now start faster on large C++
3032 * DWARF 2 Location Expressions
3034 GDB support for location expressions has been extended to support function
3035 arguments and frame bases. Older versions of GDB could crash when they
3038 * C++ nested types and namespaces
3040 GDB's support for nested types and namespaces in C++ has been
3041 improved, especially if you use the DWARF 2 debugging format. (This
3042 is the default for recent versions of GCC on most platforms.)
3043 Specifically, if you have a class "Inner" defined within a class or
3044 namespace "Outer", then GDB realizes that the class's name is
3045 "Outer::Inner", not simply "Inner". This should greatly reduce the
3046 frequency of complaints about not finding RTTI symbols. In addition,
3047 if you are stopped at inside of a function defined within a namespace,
3048 GDB modifies its name lookup accordingly.
3050 * New native configurations
3052 NetBSD/amd64 x86_64-*-netbsd*
3053 OpenBSD/amd64 x86_64-*-openbsd*
3054 OpenBSD/alpha alpha*-*-openbsd*
3055 OpenBSD/sparc sparc-*-openbsd*
3056 OpenBSD/sparc64 sparc64-*-openbsd*
3058 * New debugging protocols
3060 M32R with SDI protocol m32r-*-elf*
3062 * "set prompt-escape-char" command deleted.
3064 The command "set prompt-escape-char" has been deleted. This command,
3065 and its very obscure effet on GDB's prompt, was never documented,
3066 tested, nor mentioned in the NEWS file.
3068 * OBSOLETE configurations and files
3070 Configurations that have been declared obsolete in this release have
3071 been commented out. Unless there is activity to revive these
3072 configurations, the next release of GDB will have their sources
3073 permanently REMOVED.
3075 Sun 3, running SunOS 3 m68*-*-sunos3*
3076 Sun 3, running SunOS 4 m68*-*-sunos4*
3077 Sun 2, running SunOS 3 m68000-*-sunos3*
3078 Sun 2, running SunOS 4 m68000-*-sunos4*
3079 Motorola 680x0 running LynxOS m68*-*-lynxos*
3080 AT&T 3b1/Unix pc m68*-att-*
3081 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3082 decstation mips-dec-* mips-little-*
3083 riscos mips-*-riscos* mips-*-sysv*
3084 sonymips mips-sony-*
3085 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3087 * REMOVED configurations and files
3089 SGI Irix-4.x mips-sgi-irix4 or iris4
3090 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3091 Z8000 simulator z8k-zilog-none or z8ksim
3092 Matsushita MN10200 w/simulator mn10200-*-*
3093 H8/500 simulator h8500-hitachi-hms or h8500hms
3094 HP/PA running BSD hppa*-*-bsd*
3095 HP/PA running OSF/1 hppa*-*-osf*
3096 HP/PA Pro target hppa*-*-pro*
3097 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3098 386BSD i[3456]86-*-bsd*
3099 Sequent family i[3456]86-sequent-sysv4*
3100 i[3456]86-sequent-sysv*
3101 i[3456]86-sequent-bsd*
3102 SPARC running LynxOS sparc-*-lynxos*
3103 SPARC running SunOS 4 sparc-*-sunos4*
3104 Tsqware Sparclet sparclet-*-*
3105 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3107 *** Changes in GDB 6.0:
3111 Support for debugging the Objective-C programming language has been
3112 integrated into GDB.
3114 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3116 DWARF 2's Call Frame Information makes available compiler generated
3117 information that more exactly describes the program's run-time stack.
3118 By using this information, GDB is able to provide more robust stack
3121 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3122 have been updated to use a new backtrace mechanism which includes
3123 DWARF 2 CFI support.
3127 GDB's remote protocol has been extended to include support for hosted
3128 file I/O (where the remote target uses GDB's file system). See GDB's
3129 remote protocol documentation for details.
3131 * All targets using the new architecture framework.
3133 All of GDB's targets have been updated to use the new internal
3134 architecture framework. The way is now open for future GDB releases
3135 to include cross-architecture native debugging support (i386 on amd64,
3138 * GNU/Linux's Thread Local Storage (TLS)
3140 GDB now includes support for for the GNU/Linux implementation of
3141 per-thread variables.
3143 * GNU/Linux's Native POSIX Thread Library (NPTL)
3145 GDB's thread code has been updated to work with either the new
3146 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3148 * Separate debug info.
3150 GDB, in conjunction with BINUTILS, now supports a mechanism for
3151 automatically loading debug information from a separate file. Instead
3152 of shipping full debug and non-debug versions of system libraries,
3153 system integrators can now instead ship just the stripped libraries
3154 and optional debug files.
3156 * DWARF 2 Location Expressions
3158 DWARF 2 Location Expressions allow the compiler to more completely
3159 describe the location of variables (even in optimized code) to the
3162 GDB now includes preliminary support for location expressions (support
3163 for DW_OP_piece is still missing).
3167 A number of long standing bugs that caused GDB to die while starting a
3168 Java application have been fixed. GDB's Java support is now
3169 considered "useable".
3171 * GNU/Linux support for fork, vfork, and exec.
3173 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3174 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3177 * GDB supports logging output to a file
3179 There are two new commands, "set logging" and "show logging", which can be
3180 used to capture GDB's output to a file.
3182 * The meaning of "detach" has changed for gdbserver
3184 The "detach" command will now resume the application, as documented. To
3185 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3188 * d10v, m68hc11 `regs' command deprecated
3190 The `info registers' command has been updated so that it displays the
3191 registers using a format identical to the old `regs' command.
3195 A new command, "maint set profile on/off", has been added. This command can
3196 be used to enable or disable profiling while running GDB, to profile a
3197 session or a set of commands. In addition there is a new configure switch,
3198 "--enable-profiling", which will cause GDB to be compiled with profiling
3199 data, for more informative profiling results.
3201 * Default MI syntax changed to "mi2".
3203 The default MI (machine interface) syntax, enabled by the command line
3204 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3205 "mi1", can be enabled by specifying the option "-i=mi1".
3207 Support for the original "mi0" syntax (included in GDB 5.0) has been
3210 Fix for gdb/192: removed extraneous space when displaying frame level.
3211 Fix for gdb/672: update changelist is now output in mi list format.
3212 Fix for gdb/702: a -var-assign that updates the value now shows up
3213 in a subsequent -var-update.
3215 * New native configurations.
3217 FreeBSD/amd64 x86_64-*-freebsd*
3219 * Multi-arched targets.
3221 HP/PA HPUX11 hppa*-*-hpux*
3222 Renesas M32R/D w/simulator m32r-*-elf*
3224 * OBSOLETE configurations and files
3226 Configurations that have been declared obsolete in this release have
3227 been commented out. Unless there is activity to revive these
3228 configurations, the next release of GDB will have their sources
3229 permanently REMOVED.
3231 Z8000 simulator z8k-zilog-none or z8ksim
3232 Matsushita MN10200 w/simulator mn10200-*-*
3233 H8/500 simulator h8500-hitachi-hms or h8500hms
3234 HP/PA running BSD hppa*-*-bsd*
3235 HP/PA running OSF/1 hppa*-*-osf*
3236 HP/PA Pro target hppa*-*-pro*
3237 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3238 Sequent family i[3456]86-sequent-sysv4*
3239 i[3456]86-sequent-sysv*
3240 i[3456]86-sequent-bsd*
3241 Tsqware Sparclet sparclet-*-*
3242 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3244 * REMOVED configurations and files
3247 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3248 IBM AIX PS/2 i[3456]86-*-aix
3249 i386 running Mach 3.0 i[3456]86-*-mach3*
3250 i386 running Mach i[3456]86-*-mach*
3251 i386 running OSF/1 i[3456]86-*osf1mk*
3252 HP/Apollo 68k Family m68*-apollo*-sysv*,
3254 m68*-hp-bsd*, m68*-hp-hpux*
3255 Argonaut Risc Chip (ARC) arc-*-*
3256 Mitsubishi D30V d30v-*-*
3257 Fujitsu FR30 fr30-*-elf*
3258 OS/9000 i[34]86-*-os9k
3259 I960 with MON960 i960-*-coff
3261 * MIPS $fp behavior changed
3263 The convenience variable $fp, for the MIPS, now consistently returns
3264 the address of the current frame's base. Previously, depending on the
3265 context, $fp could refer to either $sp or the current frame's base
3266 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3267 The GNU Source-Level Debugger''.
3269 *** Changes in GDB 5.3:
3271 * GNU/Linux shared library multi-threaded performance improved.
3273 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3274 `/proc', in preference to `ptrace' for memory reads. This may result
3275 in an improvement in the start-up time of multi-threaded, shared
3276 library applications when run under GDB. One GDB user writes: ``loads
3277 shared libs like mad''.
3279 * ``gdbserver'' now supports multi-threaded applications on some targets
3281 Support for debugging multi-threaded applications which use
3282 the GNU/Linux LinuxThreads package has been added for
3283 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3284 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3286 * GDB now supports C/C++ preprocessor macros.
3288 GDB now expands preprocessor macro invocations in C/C++ expressions,
3289 and provides various commands for showing macro definitions and how
3292 The new command `macro expand EXPRESSION' expands any macro
3293 invocations in expression, and shows the result.
3295 The new command `show macro MACRO-NAME' shows the definition of the
3296 macro named MACRO-NAME, and where it was defined.
3298 Most compilers don't include information about macros in the debugging
3299 information by default. In GCC 3.1, for example, you need to compile
3300 your program with the options `-gdwarf-2 -g3'. If the macro
3301 information is present in the executable, GDB will read it.
3303 * Multi-arched targets.
3305 DEC Alpha (partial) alpha*-*-*
3306 DEC VAX (partial) vax-*-*
3308 National Semiconductor NS32000 (partial) ns32k-*-*
3309 Motorola 68000 (partial) m68k-*-*
3310 Motorola MCORE mcore-*-*
3314 Fujitsu FRV architecture added by Red Hat frv*-*-*
3317 * New native configurations
3319 Alpha NetBSD alpha*-*-netbsd*
3320 SH NetBSD sh*-*-netbsdelf*
3321 MIPS NetBSD mips*-*-netbsd*
3322 UltraSPARC NetBSD sparc64-*-netbsd*
3324 * OBSOLETE configurations and files
3326 Configurations that have been declared obsolete in this release have
3327 been commented out. Unless there is activity to revive these
3328 configurations, the next release of GDB will have their sources
3329 permanently REMOVED.
3331 Mitsubishi D30V d30v-*-*
3332 OS/9000 i[34]86-*-os9k
3333 IBM AIX PS/2 i[3456]86-*-aix
3334 Fujitsu FR30 fr30-*-elf*
3335 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3336 Argonaut Risc Chip (ARC) arc-*-*
3337 i386 running Mach 3.0 i[3456]86-*-mach3*
3338 i386 running Mach i[3456]86-*-mach*
3339 i386 running OSF/1 i[3456]86-*osf1mk*
3340 HP/Apollo 68k Family m68*-apollo*-sysv*,
3342 m68*-hp-bsd*, m68*-hp-hpux*
3343 I960 with MON960 i960-*-coff
3345 * OBSOLETE languages
3347 CHILL, a Pascal like language used by telecommunications companies.
3349 * REMOVED configurations and files
3351 AMD 29k family via UDI a29k-amd-udi, udi29k
3352 A29K VxWorks a29k-*-vxworks
3353 AMD 29000 embedded, using EBMON a29k-none-none
3354 AMD 29000 embedded with COFF a29k-none-coff
3355 AMD 29000 embedded with a.out a29k-none-aout
3357 testsuite/gdb.hp/gdb.threads-hp/ directory
3359 * New command "set max-user-call-depth <nnn>"
3361 This command allows the user to limit the call depth of user-defined
3362 commands. The default is 1024.
3364 * Changes in FreeBSD/i386 native debugging.
3366 Support for the "generate-core-file" has been added.
3368 * New commands "dump", "append", and "restore".
3370 These commands allow data to be copied from target memory
3371 to a bfd-format or binary file (dump and append), and back
3372 from a file into memory (restore).
3374 * Improved "next/step" support on multi-processor Alpha Tru64.
3376 The previous single-step mechanism could cause unpredictable problems,
3377 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3378 of a software single-step mechanism prevents this.
3380 *** Changes in GDB 5.2.1:
3388 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3389 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3390 Fix, by Joel Brobecker imported from mainline.
3392 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3393 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3394 Fix, by Fred Fish, imported from mainline.
3396 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3397 Surprisingly enough, it works now.
3398 By Michal Ludvig, imported from mainline.
3400 i386 hardware watchpoint support:
3401 avoid misses on second run for some targets.
3402 By Pierre Muller, imported from mainline.
3404 *** Changes in GDB 5.2:
3406 * New command "set trust-readonly-sections on[off]".
3408 This command is a hint that tells gdb that read-only sections
3409 really are read-only (ie. that their contents will not change).
3410 In this mode, gdb will go to the object file rather than the
3411 target to read memory from read-only sections (such as ".text").
3412 This can be a significant performance improvement on some
3413 (notably embedded) targets.
3415 * New command "generate-core-file" (or "gcore").
3417 This new gdb command allows the user to drop a core file of the child
3418 process state at any time. So far it's been implemented only for
3419 GNU/Linux and Solaris, but should be relatively easily ported to other
3420 hosts. Argument is core file name (defaults to core.<pid>).
3422 * New command line option
3424 GDB now accepts --pid or -p followed by a process id.
3426 * Change in command line behavior -- corefiles vs. process ids.
3428 There is a subtle behavior in the way in which GDB handles
3429 command line arguments. The first non-flag argument is always
3430 a program to debug, but the second non-flag argument may either
3431 be a corefile or a process id. Previously, GDB would attempt to
3432 open the second argument as a corefile, and if that failed, would
3433 issue a superfluous error message and then attempt to attach it as
3434 a process. Now, if the second argument begins with a non-digit,
3435 it will be treated as a corefile. If it begins with a digit,
3436 GDB will attempt to attach it as a process, and if no such process
3437 is found, will then attempt to open it as a corefile.
3439 * Changes in ARM configurations.
3441 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3442 configuration is fully multi-arch.
3444 * New native configurations
3446 ARM NetBSD arm*-*-netbsd*
3447 x86 OpenBSD i[3456]86-*-openbsd*
3448 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3449 Sparc64 running FreeBSD sparc64-*-freebsd*
3453 Sanyo XStormy16 xstormy16-elf
3455 * OBSOLETE configurations and files
3457 Configurations that have been declared obsolete in this release have
3458 been commented out. Unless there is activity to revive these
3459 configurations, the next release of GDB will have their sources
3460 permanently REMOVED.
3462 AMD 29k family via UDI a29k-amd-udi, udi29k
3463 A29K VxWorks a29k-*-vxworks
3464 AMD 29000 embedded, using EBMON a29k-none-none
3465 AMD 29000 embedded with COFF a29k-none-coff
3466 AMD 29000 embedded with a.out a29k-none-aout
3468 testsuite/gdb.hp/gdb.threads-hp/ directory
3470 * REMOVED configurations and files
3472 TI TMS320C80 tic80-*-*
3474 PowerPC Solaris powerpcle-*-solaris*
3475 PowerPC Windows NT powerpcle-*-cygwin32
3476 PowerPC Netware powerpc-*-netware*
3477 Harris/CXUX m88k m88*-harris-cxux*
3478 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3479 ns32k-utek-sysv* ns32k-utek-*
3480 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3481 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3482 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3483 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3484 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3486 * Changes to command line processing
3488 The new `--args' feature can be used to specify command-line arguments
3489 for the inferior from gdb's command line.
3491 * Changes to key bindings
3493 There is a new `operate-and-get-next' function bound to `C-o'.
3495 *** Changes in GDB 5.1.1
3497 Fix compile problem on DJGPP.
3499 Fix a problem with floating-point registers on the i386 being
3502 Fix to stop GDB crashing on .debug_str debug info.
3504 Numerous documentation fixes.
3506 Numerous testsuite fixes.
3508 *** Changes in GDB 5.1:
3510 * New native configurations
3512 Alpha FreeBSD alpha*-*-freebsd*
3513 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3514 MIPS GNU/Linux mips*-*-linux*
3515 MIPS SGI Irix 6.x mips*-sgi-irix6*
3516 ia64 AIX ia64-*-aix*
3517 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3521 Motorola 68HC11 and 68HC12 m68hc11-elf
3523 UltraSparc running GNU/Linux sparc64-*-linux*
3525 * OBSOLETE configurations and files
3527 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3528 Harris/CXUX m88k m88*-harris-cxux*
3529 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3530 ns32k-utek-sysv* ns32k-utek-*
3531 TI TMS320C80 tic80-*-*
3533 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3534 PowerPC Solaris powerpcle-*-solaris*
3535 PowerPC Windows NT powerpcle-*-cygwin32
3536 PowerPC Netware powerpc-*-netware*
3537 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3538 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3539 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3540 Apple Macintosh (MPW) host N/A
3542 stuff.c (Program to stuff files into a specially prepared space in kdb)
3543 kdb-start.c (Main loop for the standalone kernel debugger)
3545 Configurations that have been declared obsolete in this release have
3546 been commented out. Unless there is activity to revive these
3547 configurations, the next release of GDB will have their sources
3548 permanently REMOVED.
3550 * REMOVED configurations and files
3552 Altos 3068 m68*-altos-*
3553 Convex c1-*-*, c2-*-*
3555 ARM RISCix arm-*-* (as host)
3559 * GDB has been converted to ISO C.
3561 GDB's source code has been converted to ISO C. In particular, the
3562 sources are fully protoized, and rely on standard headers being
3567 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3569 * The MI enabled by default.
3571 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3572 revised and enabled by default. Packages which use GDB as a debugging
3573 engine behind a UI or another front end are encouraged to switch to
3574 using the GDB/MI interface, instead of the old annotations interface
3575 which is now deprecated.
3577 * Support for debugging Pascal programs.
3579 GDB now includes support for debugging Pascal programs. The following
3580 main features are supported:
3582 - Pascal-specific data types such as sets;
3584 - automatic recognition of Pascal sources based on file-name
3587 - Pascal-style display of data types, variables, and functions;
3589 - a Pascal expression parser.
3591 However, some important features are not yet supported.
3593 - Pascal string operations are not supported at all;
3595 - there are some problems with boolean types;
3597 - Pascal type hexadecimal constants are not supported
3598 because they conflict with the internal variables format;
3600 - support for Pascal objects and classes is not full yet;
3602 - unlike Pascal, GDB is case-sensitive for symbol names.
3604 * Changes in completion.
3606 Commands such as `shell', `run' and `set args', which pass arguments
3607 to inferior programs, now complete on file names, similar to what
3608 users expect at the shell prompt.
3610 Commands which accept locations, such as `disassemble', `print',
3611 `breakpoint', `until', etc. now complete on filenames as well as
3612 program symbols. Thus, if you type "break foob TAB", and the source
3613 files linked into the programs include `foobar.c', that file name will
3614 be one of the candidates for completion. However, file names are not
3615 considered for completion after you typed a colon that delimits a file
3616 name from a name of a function in that file, as in "break foo.c:bar".
3618 `set demangle-style' completes on available demangling styles.
3620 * New platform-independent commands:
3622 It is now possible to define a post-hook for a command as well as a
3623 hook that runs before the command. For more details, see the
3624 documentation of `hookpost' in the GDB manual.
3626 * Changes in GNU/Linux native debugging.
3628 Support for debugging multi-threaded programs has been completely
3629 revised for all platforms except m68k and sparc. You can now debug as
3630 many threads as your system allows you to have.
3632 Attach/detach is supported for multi-threaded programs.
3634 Support for SSE registers was added for x86. This doesn't work for
3635 multi-threaded programs though.
3637 * Changes in MIPS configurations.
3639 Multi-arch support is enabled for all MIPS configurations.
3641 GDB can now be built as native debugger on SGI Irix 6.x systems for
3642 debugging n32 executables. (Debugging 64-bit executables is not yet
3645 * Unified support for hardware watchpoints in all x86 configurations.
3647 Most (if not all) native x86 configurations support hardware-assisted
3648 breakpoints and watchpoints in a unified manner. This support
3649 implements debug register sharing between watchpoints, which allows to
3650 put a virtually infinite number of watchpoints on the same address,
3651 and also supports watching regions up to 16 bytes with several debug
3654 The new maintenance command `maintenance show-debug-regs' toggles
3655 debugging print-outs in functions that insert, remove, and test
3656 watchpoints and hardware breakpoints.
3658 * Changes in the DJGPP native configuration.
3660 New command ``info dos sysinfo'' displays assorted information about
3661 the CPU, OS, memory, and DPMI server.
3663 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3664 display information about segment descriptors stored in GDT, LDT, and
3667 New commands ``info dos pde'' and ``info dos pte'' display entries
3668 from Page Directory and Page Tables (for now works with CWSDPMI only).
3669 New command ``info dos address-pte'' displays the Page Table entry for
3670 a given linear address.
3672 GDB can now pass command lines longer than 126 characters to the
3673 program being debugged (requires an update to the libdbg.a library
3674 which is part of the DJGPP development kit).
3676 DWARF2 debug info is now supported.
3678 It is now possible to `step' and `next' through calls to `longjmp'.
3680 * Changes in documentation.
3682 All GDB documentation was converted to GFDL, the GNU Free
3683 Documentation License.
3685 Tracepoints-related commands are now fully documented in the GDB
3688 TUI, the Text-mode User Interface, is now documented in the manual.
3690 Tracepoints-related commands are now fully documented in the GDB
3693 The "GDB Internals" manual now has an index. It also includes
3694 documentation of `ui_out' functions, GDB coding standards, x86
3695 hardware watchpoints, and memory region attributes.
3697 * GDB's version number moved to ``version.in''
3699 The Makefile variable VERSION has been replaced by the file
3700 ``version.in''. People creating GDB distributions should update the
3701 contents of this file.
3705 GUD support is now a standard part of the EMACS distribution.
3707 *** Changes in GDB 5.0:
3709 * Improved support for debugging FP programs on x86 targets
3711 Unified and much-improved support for debugging floating-point
3712 programs on all x86 targets. In particular, ``info float'' now
3713 displays the FP registers in the same format on all x86 targets, with
3714 greater level of detail.
3716 * Improvements and bugfixes in hardware-assisted watchpoints
3718 It is now possible to watch array elements, struct members, and
3719 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3720 on x86 targets no longer erroneously trigger when the address is
3723 * Improvements in the native DJGPP version of GDB
3725 The distribution now includes all the scripts and auxiliary files
3726 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3727 machines ``out of the box''.
3729 The DJGPP version can now debug programs that use signals. It is
3730 possible to catch signals that happened in the debuggee, deliver
3731 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3732 would kill the program being debugged.) Programs that hook hardware
3733 interrupts (keyboard, timer, etc.) can also be debugged.
3735 It is now possible to debug DJGPP programs that redirect their
3736 standard handles or switch them to raw (as opposed to cooked) mode, or
3737 even close them. The command ``run < foo > bar'' works as expected,
3738 and ``info terminal'' reports useful information about the debuggee's
3739 terminal, including raw/cooked mode, redirection, etc.
3741 The DJGPP version now uses termios functions for console I/O, which
3742 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3745 DOS-style file names with drive letters are now fully supported by
3748 It is now possible to debug DJGPP programs that switch their working
3749 directory. It is also possible to rerun the debuggee any number of
3750 times without restarting GDB; thus, you can use the same setup,
3751 breakpoints, etc. for many debugging sessions.
3753 * New native configurations
3755 ARM GNU/Linux arm*-*-linux*
3756 PowerPC GNU/Linux powerpc-*-linux*
3760 Motorola MCore mcore-*-*
3761 x86 VxWorks i[3456]86-*-vxworks*
3762 PowerPC VxWorks powerpc-*-vxworks*
3763 TI TMS320C80 tic80-*-*
3765 * OBSOLETE configurations
3767 Altos 3068 m68*-altos-*
3768 Convex c1-*-*, c2-*-*
3770 ARM RISCix arm-*-* (as host)
3773 Configurations that have been declared obsolete will be commented out,
3774 but the code will be left in place. If there is no activity to revive
3775 these configurations before the next release of GDB, the sources will
3776 be permanently REMOVED.
3778 * Gould support removed
3780 Support for the Gould PowerNode and NP1 has been removed.
3782 * New features for SVR4
3784 On SVR4 native platforms (such as Solaris), if you attach to a process
3785 without first loading a symbol file, GDB will now attempt to locate and
3786 load symbols from the running process's executable file.
3788 * Many C++ enhancements
3790 C++ support has been greatly improved. Overload resolution now works properly
3791 in almost all cases. RTTI support is on the way.
3793 * Remote targets can connect to a sub-program
3795 A popen(3) style serial-device has been added. This device starts a
3796 sub-process (such as a stand-alone simulator) and then communicates
3797 with that. The sub-program to run is specified using the syntax
3798 ``|<program> <args>'' vis:
3800 (gdb) set remotedebug 1
3801 (gdb) target extended-remote |mn10300-elf-sim program-args
3803 * MIPS 64 remote protocol
3805 A long standing bug in the mips64 remote protocol where by GDB
3806 expected certain 32 bit registers (ex SR) to be transfered as 32
3807 instead of 64 bits has been fixed.
3809 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3810 added to provide backward compatibility with older versions of GDB.
3812 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3814 The command ``set remotebinarydownload'' command has been replaced by
3815 ``set remote X-packet''. Other commands in ``set remote'' family
3816 include ``set remote P-packet''.
3818 * Breakpoint commands accept ranges.
3820 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3821 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3822 ``tracepoint passcount'' also accepts a range of tracepoints.
3824 * ``apropos'' command added.
3826 The ``apropos'' command searches through command names and
3827 documentation strings, printing out matches, making it much easier to
3828 try to find a command that does what you are looking for.
3832 A new machine oriented interface (MI) has been added to GDB. This
3833 interface is designed for debug environments running GDB as a separate
3834 process. This is part of the long term libGDB project. See the
3835 "GDB/MI" chapter of the GDB manual for further information. It can be
3836 enabled by configuring with:
3838 .../configure --enable-gdbmi
3840 *** Changes in GDB-4.18:
3842 * New native configurations
3844 HP-UX 10.20 hppa*-*-hpux10.20
3845 HP-UX 11.x hppa*-*-hpux11.0*
3846 M68K GNU/Linux m68*-*-linux*
3850 Fujitsu FR30 fr30-*-elf*
3851 Intel StrongARM strongarm-*-*
3852 Mitsubishi D30V d30v-*-*
3854 * OBSOLETE configurations
3856 Gould PowerNode, NP1 np1-*-*, pn-*-*
3858 Configurations that have been declared obsolete will be commented out,
3859 but the code will be left in place. If there is no activity to revive
3860 these configurations before the next release of GDB, the sources will
3861 be permanently REMOVED.
3865 As a compatibility experiment, GDB's source files buildsym.h and
3866 buildsym.c have been converted to pure standard C, no longer
3867 containing any K&R compatibility code. We believe that all systems in
3868 use today either come with a standard C compiler, or have a GCC port
3869 available. If this is not true, please report the affected
3870 configuration to bug-gdb@gnu.org immediately. See the README file for
3871 information about getting a standard C compiler if you don't have one
3876 GDB now uses readline 2.2.
3878 * set extension-language
3880 You can now control the mapping between filename extensions and source
3881 languages by using the `set extension-language' command. For instance,
3882 you can ask GDB to treat .c files as C++ by saying
3883 set extension-language .c c++
3884 The command `info extensions' lists all of the recognized extensions
3885 and their associated languages.
3887 * Setting processor type for PowerPC and RS/6000
3889 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3890 you can use the `set processor' command to specify what variant of the
3891 PowerPC family you are debugging. The command
3895 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3896 following PowerPC and RS6000 variants:
3898 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3899 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3901 403GC IBM PowerPC 403GC
3902 505 Motorola PowerPC 505
3903 860 Motorola PowerPC 860 or 850
3904 601 Motorola PowerPC 601
3905 602 Motorola PowerPC 602
3906 603 Motorola/IBM PowerPC 603 or 603e
3907 604 Motorola PowerPC 604 or 604e
3908 750 Motorola/IBM PowerPC 750 or 750
3910 At the moment, this command just tells GDB what to name the
3911 special-purpose processor registers. Since almost all the affected
3912 registers are inaccessible to user-level programs, this command is
3913 only useful for remote debugging in its present form.
3917 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3918 more extensive support for HP-UX. Added features include shared
3919 library support, kernel threads and hardware watchpoints for 11.00,
3920 support for HP's ANSI C and C++ compilers, and a compatibility mode
3921 for xdb and dbx commands.
3925 HP's donation includes the new concept of catchpoints, which is a
3926 generalization of the old catch command. On HP-UX, it is now possible
3927 to catch exec, fork, and vfork, as well as library loading.
3929 This means that the existing catch command has changed; its first
3930 argument now specifies the type of catch to be set up. See the
3931 output of "help catch" for a list of catchpoint types.
3933 * Debugging across forks
3935 On HP-UX, you can choose which process to debug when a fork() happens
3940 HP has donated a curses-based terminal user interface (TUI). To get
3941 it, build with --enable-tui. Although this can be enabled for any
3942 configuration, at present it only works for native HP debugging.
3944 * GDB remote protocol additions
3946 A new protocol packet 'X' that writes binary data is now available.
3947 Default behavior is to try 'X', then drop back to 'M' if the stub
3948 fails to respond. The settable variable `remotebinarydownload'
3949 allows explicit control over the use of 'X'.
3951 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3952 full 64-bit address. The command
3954 set remoteaddresssize 32
3956 can be used to revert to the old behaviour. For existing remote stubs
3957 the change should not be noticed, as the additional address information
3960 In order to assist in debugging stubs, you may use the maintenance
3961 command `packet' to send any text string to the stub. For instance,
3963 maint packet heythere
3965 sends the packet "$heythere#<checksum>". Note that it is very easy to
3966 disrupt a debugging session by sending the wrong packet at the wrong
3969 The compare-sections command allows you to compare section data on the
3970 target to what is in the executable file without uploading or
3971 downloading, by comparing CRC checksums.
3973 * Tracing can collect general expressions
3975 You may now collect general expressions at tracepoints. This requires
3976 further additions to the target-side stub; see tracepoint.c and
3977 doc/agentexpr.texi for further details.
3979 * mask-address variable for Mips
3981 For Mips targets, you may control the zeroing of the upper 32 bits of
3982 a 64-bit address by entering `set mask-address on'. This is mainly
3983 of interest to users of embedded R4xxx and R5xxx processors.
3985 * Higher serial baud rates
3987 GDB's serial code now allows you to specify baud rates 57600, 115200,
3988 230400, and 460800 baud. (Note that your host system may not be able
3989 to achieve all of these rates.)
3993 The i960 configuration now includes an initial implementation of a
3994 builtin simulator, contributed by Jim Wilson.
3997 *** Changes in GDB-4.17:
3999 * New native configurations
4001 Alpha GNU/Linux alpha*-*-linux*
4002 Unixware 2.x i[3456]86-unixware2*
4003 Irix 6.x mips*-sgi-irix6*
4004 PowerPC GNU/Linux powerpc-*-linux*
4005 PowerPC Solaris powerpcle-*-solaris*
4006 Sparc GNU/Linux sparc-*-linux*
4007 Motorola sysV68 R3V7.1 m68k-motorola-sysv
4011 Argonaut Risc Chip (ARC) arc-*-*
4012 Hitachi H8/300S h8300*-*-*
4013 Matsushita MN10200 w/simulator mn10200-*-*
4014 Matsushita MN10300 w/simulator mn10300-*-*
4015 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4016 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4017 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4018 Mitsubishi D10V w/simulator d10v-*-*
4019 Mitsubishi M32R/D w/simulator m32r-*-elf*
4020 Tsqware Sparclet sparclet-*-*
4021 NEC V850 w/simulator v850-*-*
4023 * New debugging protocols
4025 ARM with RDI protocol arm*-*-*
4026 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4027 DDB and LSI variants of PMON protocol mips*-*-*
4028 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4029 PowerPC with SDS protocol powerpc{,le}-*-eabi
4030 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4034 All configurations can now understand and use the DWARF 2 debugging
4035 format. The choice is automatic, if the symbol file contains DWARF 2
4040 GDB now includes basic Java language support. This support is
4041 only useful with Java compilers that produce native machine code.
4043 * solib-absolute-prefix and solib-search-path
4045 For SunOS and SVR4 shared libraries, you may now set the prefix for
4046 loading absolute shared library symbol files, and the search path for
4047 locating non-absolute shared library symbol files.
4049 * Live range splitting
4051 GDB can now effectively debug code for which GCC has performed live
4052 range splitting as part of its optimization. See gdb/doc/LRS for
4053 more details on the expected format of the stabs information.
4057 GDB's support for the GNU Hurd, including thread debugging, has been
4058 updated to work with current versions of the Hurd.
4062 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4063 instruction set. ARM GDB automatically detects when Thumb
4064 instructions are in use, and adjusts disassembly and backtracing
4069 GDB's MIPS target configurations now handle the MIP16 16-bit
4074 GDB now includes support for overlays; if an executable has been
4075 linked such that multiple sections are based at the same address, GDB
4076 will decide which section to use for symbolic info. You can choose to
4077 control the decision manually, using overlay commands, or implement
4078 additional target-side support and use "overlay load-target" to bring
4079 in the overlay mapping. Do "help overlay" for more detail.
4083 The command "info symbol <address>" displays information about
4084 the symbol at the specified address.
4088 The standard remote protocol now includes an extension that allows
4089 asynchronous collection and display of trace data. This requires
4090 extensive support in the target-side debugging stub. Tracing mode
4091 includes a new interaction mode in GDB and new commands: see the
4092 file tracepoint.c for more details.
4096 Configurations for embedded MIPS now include a simulator contributed
4097 by Cygnus Solutions. The simulator supports the instruction sets
4098 of most MIPS variants.
4102 Sparc configurations may now include the ERC32 simulator contributed
4103 by the European Space Agency. The simulator is not built into
4104 Sparc targets by default; configure with --enable-sim to include it.
4108 For target configurations that may include multiple variants of a
4109 basic architecture (such as MIPS and SH), you may now set the
4110 architecture explicitly. "set arch" sets, "info arch" lists
4111 the possible architectures.
4113 *** Changes in GDB-4.16:
4115 * New native configurations
4117 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4118 M68K NetBSD m68k-*-netbsd*
4119 PowerPC AIX 4.x powerpc-*-aix*
4120 PowerPC MacOS powerpc-*-macos*
4121 PowerPC Windows NT powerpcle-*-cygwin32
4122 RS/6000 AIX 4.x rs6000-*-aix4*
4126 ARM with RDP protocol arm-*-*
4127 I960 with MON960 i960-*-coff
4128 MIPS VxWorks mips*-*-vxworks*
4129 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4130 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4132 Matra Sparclet sparclet-*-*
4136 The powerpc-eabi configuration now includes the PSIM simulator,
4137 contributed by Andrew Cagney, with assistance from Mike Meissner.
4138 PSIM is a very elaborate model of the PowerPC, including not only
4139 basic instruction set execution, but also details of execution unit
4140 performance and I/O hardware. See sim/ppc/README for more details.
4144 GDB now works with Solaris 2.5.
4146 * Windows 95/NT native
4148 GDB will now work as a native debugger on Windows 95 and Windows NT.
4149 To build it from source, you must use the "gnu-win32" environment,
4150 which uses a DLL to emulate enough of Unix to run the GNU tools.
4151 Further information, binaries, and sources are available at
4152 ftp.cygnus.com, under pub/gnu-win32.
4154 * dont-repeat command
4156 If a user-defined command includes the command `dont-repeat', then the
4157 command will not be repeated if the user just types return. This is
4158 useful if the command is time-consuming to run, so that accidental
4159 extra keystrokes don't run the same command many times.
4161 * Send break instead of ^C
4163 The standard remote protocol now includes an option to send a break
4164 rather than a ^C to the target in order to interrupt it. By default,
4165 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4167 * Remote protocol timeout
4169 The standard remote protocol includes a new variable `remotetimeout'
4170 that allows you to set the number of seconds before GDB gives up trying
4171 to read from the target. The default value is 2.
4173 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4175 By default GDB will automatically keep track of objects as they are
4176 loaded and unloaded by the dynamic linker. By using the command `set
4177 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4178 when shared library events occur, thus allowing you to set breakpoints
4179 in shared libraries which are explicitly loaded by the inferior.
4181 Note this feature does not work on hpux8. On hpux9 you must link
4182 /usr/lib/end.o into your program. This feature should work
4183 automatically on hpux10.
4185 * Irix 5.x hardware watchpoint support
4187 Irix 5 configurations now support the use of hardware watchpoints.
4189 * Mips protocol "SYN garbage limit"
4191 When debugging a Mips target using the `target mips' protocol, you
4192 may set the number of characters that GDB will ignore by setting
4193 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4194 every character. The default value is 1050.
4196 * Recording and replaying remote debug sessions
4198 If you set `remotelogfile' to the name of a file, gdb will write to it
4199 a recording of a remote debug session. This recording may then be
4200 replayed back to gdb using "gdbreplay". See gdbserver/README for
4201 details. This is useful when you have a problem with GDB while doing
4202 remote debugging; you can make a recording of the session and send it
4203 to someone else, who can then recreate the problem.
4205 * Speedups for remote debugging
4207 GDB includes speedups for downloading and stepping MIPS systems using
4208 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4209 and more efficient S-record downloading.
4211 * Memory use reductions and statistics collection
4213 GDB now uses less memory and reports statistics about memory usage.
4214 Try the `maint print statistics' command, for example.
4216 *** Changes in GDB-4.15:
4218 * Psymtabs for XCOFF
4220 The symbol reader for AIX GDB now uses partial symbol tables. This
4221 can greatly improve startup time, especially for large executables.
4223 * Remote targets use caching
4225 Remote targets now use a data cache to speed up communication with the
4226 remote side. The data cache could lead to incorrect results because
4227 it doesn't know about volatile variables, thus making it impossible to
4228 debug targets which use memory mapped I/O devices. `set remotecache
4229 off' turns the the data cache off.
4231 * Remote targets may have threads
4233 The standard remote protocol now includes support for multiple threads
4234 in the target system, using new protocol commands 'H' and 'T'. See
4235 gdb/remote.c for details.
4239 If GDB is configured with `--enable-netrom', then it will include
4240 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4241 acts as though it is a bank of ROM on the target board, but you can
4242 write into it over the network. GDB's support consists only of
4243 support for fast loading into the emulated ROM; to debug, you must use
4244 another protocol, such as standard remote protocol. The usual
4245 sequence is something like
4247 target nrom <netrom-hostname>
4249 target remote <netrom-hostname>:1235
4253 GDB now includes support for the Apple Macintosh, as a host only. It
4254 may be run as either an MPW tool or as a standalone application, and
4255 it can debug through the serial port. All the usual GDB commands are
4256 available, but to the target command, you must supply "serial" as the
4257 device type instead of "/dev/ttyXX". See mpw-README in the main
4258 directory for more information on how to build. The MPW configuration
4259 scripts */mpw-config.in support only a few targets, and only the
4260 mips-idt-ecoff target has been tested.
4264 GDB configuration now uses autoconf. This is not user-visible,
4265 but does simplify configuration and building.
4269 GDB now supports hpux10.
4271 *** Changes in GDB-4.14:
4273 * New native configurations
4275 x86 FreeBSD i[345]86-*-freebsd
4276 x86 NetBSD i[345]86-*-netbsd
4277 NS32k NetBSD ns32k-*-netbsd
4278 Sparc NetBSD sparc-*-netbsd
4282 A29K VxWorks a29k-*-vxworks
4283 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4284 CPU32 EST-300 emulator m68*-*-est*
4285 PowerPC ELF powerpc-*-elf
4288 * Alpha OSF/1 support for procfs
4290 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4291 possible to attach to running processes. As the mounting of the /proc
4292 filesystem is optional on the Alpha, GDB automatically determines
4293 the availability of /proc during startup. This can lead to problems
4294 if /proc is unmounted after GDB has been started.
4296 * Arguments to user-defined commands
4298 User commands may accept up to 10 arguments separated by whitespace.
4299 Arguments are accessed within the user command via $arg0..$arg9. A
4302 print $arg0 + $arg1 + $arg2
4304 To execute the command use:
4307 Defines the command "adder" which prints the sum of its three arguments.
4308 Note the arguments are text substitutions, so they may reference variables,
4309 use complex expressions, or even perform inferior function calls.
4311 * New `if' and `while' commands
4313 This makes it possible to write more sophisticated user-defined
4314 commands. Both commands take a single argument, which is the
4315 expression to evaluate, and must be followed by the commands to
4316 execute, one per line, if the expression is nonzero, the list being
4317 terminated by the word `end'. The `if' command list may include an
4318 `else' word, which causes the following commands to be executed only
4319 if the expression is zero.
4321 * Fortran source language mode
4323 GDB now includes partial support for Fortran 77. It will recognize
4324 Fortran programs and can evaluate a subset of Fortran expressions, but
4325 variables and functions may not be handled correctly. GDB will work
4326 with G77, but does not yet know much about symbols emitted by other
4329 * Better HPUX support
4331 Most debugging facilities now work on dynamic executables for HPPAs
4332 running hpux9 or later. You can attach to running dynamically linked
4333 processes, but by default the dynamic libraries will be read-only, so
4334 for instance you won't be able to put breakpoints in them. To change
4335 that behavior do the following before running the program:
4341 This will cause the libraries to be mapped private and read-write.
4342 To revert to the normal behavior, do this:
4348 You cannot set breakpoints or examine data in the library until after
4349 the library is loaded if the function/data symbols do not have
4352 GDB can now also read debug symbols produced by the HP C compiler on
4353 HPPAs (sorry, no C++, Fortran or 68k support).
4355 * Target byte order now dynamically selectable
4357 You can choose which byte order to use with a target system, via the
4358 commands "set endian big" and "set endian little", and you can see the
4359 current setting by using "show endian". You can also give the command
4360 "set endian auto", in which case GDB will use the byte order
4361 associated with the executable. Currently, only embedded MIPS
4362 configurations support dynamic selection of target byte order.
4364 * New DOS host serial code
4366 This version uses DPMI interrupts to handle buffered I/O, so you
4367 no longer need to run asynctsr when debugging boards connected to
4370 *** Changes in GDB-4.13:
4372 * New "complete" command
4374 This lists all the possible completions for the rest of the line, if it
4375 were to be given as a command itself. This is intended for use by emacs.
4377 * Trailing space optional in prompt
4379 "set prompt" no longer adds a space for you after the prompt you set. This
4380 allows you to set a prompt which ends in a space or one that does not.
4382 * Breakpoint hit counts
4384 "info break" now displays a count of the number of times the breakpoint
4385 has been hit. This is especially useful in conjunction with "ignore"; you
4386 can ignore a large number of breakpoint hits, look at the breakpoint info
4387 to see how many times the breakpoint was hit, then run again, ignoring one
4388 less than that number, and this will get you quickly to the last hit of
4391 * Ability to stop printing at NULL character
4393 "set print null-stop" will cause GDB to stop printing the characters of
4394 an array when the first NULL is encountered. This is useful when large
4395 arrays actually contain only short strings.
4397 * Shared library breakpoints
4399 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4400 breakpoints in shared libraries before the executable is run.
4402 * Hardware watchpoints
4404 There is a new hardware breakpoint for the watch command for sparclite
4405 targets. See gdb/sparclite/hw_breakpoint.note.
4407 Hardware watchpoints are also now supported under GNU/Linux.
4411 Annotations have been added. These are for use with graphical interfaces,
4412 and are still experimental. Currently only gdba.el uses these.
4414 * Improved Irix 5 support
4416 GDB now works properly with Irix 5.2.
4418 * Improved HPPA support
4420 GDB now works properly with the latest GCC and GAS.
4422 * New native configurations
4424 Sequent PTX4 i[34]86-sequent-ptx4
4425 HPPA running OSF/1 hppa*-*-osf*
4426 Atari TT running SVR4 m68*-*-sysv4*
4427 RS/6000 LynxOS rs6000-*-lynxos*
4431 OS/9000 i[34]86-*-os9k
4432 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4435 * Hitachi SH7000 and E7000-PC ICE support
4437 There is now support for communicating with the Hitachi E7000-PC ICE.
4438 This is available automatically when GDB is configured for the SH.
4442 As usual, a variety of small fixes and improvements, both generic
4443 and configuration-specific. See the ChangeLog for more detail.
4445 *** Changes in GDB-4.12:
4447 * Irix 5 is now supported
4451 GDB-4.12 on the HPPA has a number of changes which make it unable
4452 to debug the output from the currently released versions of GCC and
4453 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4454 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4455 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4458 *** Changes in GDB-4.11:
4460 * User visible changes:
4464 The "set remotedebug" option is now consistent between the mips remote
4465 target, remote targets using the gdb-specific protocol, UDI (AMD's
4466 debug protocol for the 29k) and the 88k bug monitor. It is now an
4467 integer specifying a debug level (normally 0 or 1, but 2 means more
4468 debugging info for the mips target).
4470 * DEC Alpha native support
4472 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4473 debug info, but GDB works fairly well with the DEC compiler and should
4474 work with a future GCC release. See the README file for a few
4475 Alpha-specific notes.
4477 * Preliminary thread implementation
4479 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4481 * LynxOS native and target support for 386
4483 This release has been hosted on LynxOS 2.2, and also can be configured
4484 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4487 * Improvements in C++ mangling/demangling.
4489 This release has much better g++ debugging, specifically in name
4490 mangling/demangling, virtual function calls, print virtual table,
4491 call methods, ...etc.
4493 *** Changes in GDB-4.10:
4495 * User visible changes:
4497 Remote debugging using the GDB-specific (`target remote') protocol now
4498 supports the `load' command. This is only useful if you have some
4499 other way of getting the stub to the target system, and you can put it
4500 somewhere in memory where it won't get clobbered by the download.
4502 Filename completion now works.
4504 When run under emacs mode, the "info line" command now causes the
4505 arrow to point to the line specified. Also, "info line" prints
4506 addresses in symbolic form (as well as hex).
4508 All vxworks based targets now support a user settable option, called
4509 vxworks-timeout. This option represents the number of seconds gdb
4510 should wait for responses to rpc's. You might want to use this if
4511 your vxworks target is, perhaps, a slow software simulator or happens
4512 to be on the far side of a thin network line.
4516 This release contains support for using a DEC alpha as a GDB host for
4517 cross debugging. Native alpha debugging is not supported yet.
4520 *** Changes in GDB-4.9:
4524 This is the first GDB release which is accompanied by a matching testsuite.
4525 The testsuite requires installation of dejagnu, which should be available
4526 via ftp from most sites that carry GNU software.
4530 'Cfront' style demangling has had its name changed to 'ARM' style, to
4531 emphasize that it was written from the specifications in the C++ Annotated
4532 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4533 disclaimers, it still generated too much confusion with users attempting to
4534 use gdb with AT&T cfront.
4538 GDB now uses a standard remote interface to a simulator library.
4539 So far, the library contains simulators for the Zilog Z8001/2, the
4540 Hitachi H8/300, H8/500 and Super-H.
4542 * New targets supported
4544 H8/300 simulator h8300-hitachi-hms or h8300hms
4545 H8/500 simulator h8500-hitachi-hms or h8500hms
4546 SH simulator sh-hitachi-hms or sh
4547 Z8000 simulator z8k-zilog-none or z8ksim
4548 IDT MIPS board over serial line mips-idt-ecoff
4550 Cross-debugging to GO32 targets is supported. It requires a custom
4551 version of the i386-stub.c module which is integrated with the
4552 GO32 memory extender.
4554 * New remote protocols
4556 MIPS remote debugging protocol.
4558 * New source languages supported
4560 This version includes preliminary support for Chill, a Pascal like language
4561 used by telecommunications companies. Chill support is also being integrated
4562 into the GNU compiler, but we don't know when it will be publically available.
4565 *** Changes in GDB-4.8:
4567 * HP Precision Architecture supported
4569 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4570 version of this support was available as a set of patches from the
4571 University of Utah. GDB does not support debugging of programs
4572 compiled with the HP compiler, because HP will not document their file
4573 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4574 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4576 Many problems in the preliminary version have been fixed.
4578 * Faster and better demangling
4580 We have improved template demangling and fixed numerous bugs in the GNU style
4581 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4582 character types (wchar_t) are now supported. Demangling of each symbol is now
4583 only done once, and is cached when the symbol table for a file is read in.
4584 This results in a small increase in memory usage for C programs, a moderate
4585 increase in memory usage for C++ programs, and a fantastic speedup in
4588 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4589 from the specifications in the Annotated Reference Manual, which AT&T's
4590 compiler does not actually implement.
4592 * G++ multiple inheritance compiler problem
4594 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4595 inheritance lattices was reworked to properly discover ambiguities. We
4596 recently found an example which causes this new algorithm to fail in a
4597 very subtle way, producing bad debug information for those classes.
4598 The file 'gcc.patch' (in this directory) can be applied to gcc to
4599 circumvent the problem. A future GCC release will contain a complete
4602 The previous G++ debug info problem (mentioned below for the gdb-4.7
4603 release) is fixed in gcc version 2.3.2.
4605 * Improved configure script
4607 The `configure' script will now attempt to guess your system type if
4608 you don't supply a host system type. The old scheme of supplying a
4609 host system triplet is preferable over using this. All the magic is
4610 done in the new `config.guess' script. Examine it for details.
4612 We have also brought our configure script much more in line with the FSF's
4613 version. It now supports the --with-xxx options. In particular,
4614 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4615 The resulting GDB will not be able to read arbitrary object file formats --
4616 only the format ``expected'' to be used on the configured target system.
4617 We hope to make this the default in a future release.
4619 * Documentation improvements
4621 There's new internal documentation on how to modify GDB, and how to
4622 produce clean changes to the code. We implore people to read it
4623 before submitting changes.
4625 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4626 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4627 `info' files are also provided. To build `info' files from scratch,
4628 you will need the latest `makeinfo' release, which will be available in
4629 a future texinfo-X.Y release.
4631 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4632 We're not sure exactly which versions have this problem, but it has
4633 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4634 or better. If that isn't possible, there is a patch in
4635 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4636 around this problem.
4640 GDB now supports array constants that can be used in expressions typed in by
4641 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4642 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4645 The new directory `gdb/sparclite' contains a program that demonstrates
4646 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4648 * New native hosts supported
4650 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4651 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4653 * New targets supported
4655 AMD 29k family via UDI a29k-amd-udi or udi29k
4657 * New file formats supported
4659 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4660 HPUX core files, and SCO 3.2v2 core files.
4664 Attaching to processes now works again; thanks for the many bug reports.
4666 We have also stomped on a bunch of core dumps caused by
4667 printf_filtered("%s") problems.
4669 We eliminated a copyright problem on the rpc and ptrace header files
4670 for VxWorks, which was discovered at the last minute during the 4.7
4671 release. You should now be able to build a VxWorks GDB.
4673 You can now interrupt gdb while an attached process is running. This
4674 will cause the attached process to stop, and give control back to GDB.
4676 We fixed problems caused by using too many file descriptors
4677 for reading symbols from object files and libraries. This was
4678 especially a problem for programs that used many (~100) shared
4681 The `step' command now only enters a subroutine if there is line number
4682 information for the subroutine. Otherwise it acts like the `next'
4683 command. Previously, `step' would enter subroutines if there was
4684 any debugging information about the routine. This avoids problems
4685 when using `cc -g1' on MIPS machines.
4687 * Internal improvements
4689 GDB's internal interfaces have been improved to make it easier to support
4690 debugging of multiple languages in the future.
4692 GDB now uses a common structure for symbol information internally.
4693 Minimal symbols (derived from linkage symbols in object files), partial
4694 symbols (from a quick scan of debug information), and full symbols
4695 contain a common subset of information, making it easier to write
4696 shared code that handles any of them.
4698 * New command line options
4700 We now accept --silent as an alias for --quiet.
4704 The memory-mapped-malloc library is now licensed under the GNU Library
4705 General Public License.
4707 *** Changes in GDB-4.7:
4709 * Host/native/target split
4711 GDB has had some major internal surgery to untangle the support for
4712 hosts and remote targets. Now, when you configure GDB for a remote
4713 target, it will no longer load in all of the support for debugging
4714 local programs on the host. When fully completed and tested, this will
4715 ensure that arbitrary host/target combinations are possible.
4717 The primary conceptual shift is to separate the non-portable code in
4718 GDB into three categories. Host specific code is required any time GDB
4719 is compiled on that host, regardless of the target. Target specific
4720 code relates to the peculiarities of the target, but can be compiled on
4721 any host. Native specific code is everything else: it can only be
4722 built when the host and target are the same system. Child process
4723 handling and core file support are two common `native' examples.
4725 GDB's use of /proc for controlling Unix child processes is now cleaner.
4726 It has been split out into a single module under the `target_ops' vector,
4727 plus two native-dependent functions for each system that uses /proc.
4729 * New hosts supported
4731 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4732 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4733 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4735 * New targets supported
4737 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4738 68030 and CPU32 m68030-*-*, m68332-*-*
4740 * New native hosts supported
4742 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4743 (386bsd is not well tested yet)
4744 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4746 * New file formats supported
4748 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4749 supports reading of `a.out.adobe' object files, which are an a.out
4750 format extended with minimal information about multiple sections.
4754 `show copying' is the same as the old `info copying'.
4755 `show warranty' is the same as `info warrantee'.
4756 These were renamed for consistency. The old commands continue to work.
4758 `info handle' is a new alias for `info signals'.
4760 You can now define pre-command hooks, which attach arbitrary command
4761 scripts to any command. The commands in the hook will be executed
4762 prior to the user's command. You can also create a hook which will be
4763 executed whenever the program stops. See gdb.texinfo.
4767 We now deal with Cfront style name mangling, and can even extract type
4768 info from mangled symbols. GDB can automatically figure out which
4769 symbol mangling style your C++ compiler uses.
4771 Calling of methods and virtual functions has been improved as well.
4775 The crash that occured when debugging Sun Ansi-C compiled binaries is
4776 fixed. This was due to mishandling of the extra N_SO stabs output
4779 We also finally got Ultrix 4.2 running in house, and fixed core file
4780 support, with help from a dozen people on the net.
4782 John M. Farrell discovered that the reason that single-stepping was so
4783 slow on all of the Mips based platforms (primarily SGI and DEC) was
4784 that we were trying to demangle and lookup a symbol used for internal
4785 purposes on every instruction that was being stepped through. Changing
4786 the name of that symbol so that it couldn't be mistaken for a C++
4787 mangled symbol sped things up a great deal.
4789 Rich Pixley sped up symbol lookups in general by getting much smarter
4790 about when C++ symbol mangling is necessary. This should make symbol
4791 completion (TAB on the command line) much faster. It's not as fast as
4792 we'd like, but it's significantly faster than gdb-4.6.
4796 A new user controllable variable 'call_scratch_address' can
4797 specify the location of a scratch area to be used when GDB
4798 calls a function in the target. This is necessary because the
4799 usual method of putting the scratch area on the stack does not work
4800 in systems that have separate instruction and data spaces.
4802 We integrated changes to support the 29k UDI (Universal Debugger
4803 Interface), but discovered at the last minute that we didn't have all
4804 of the appropriate copyright paperwork. We are working with AMD to
4805 resolve this, and hope to have it available soon.
4809 We have sped up the remote serial line protocol, especially for targets
4810 with lots of registers. It now supports a new `expedited status' ('T')
4811 message which can be used in place of the existing 'S' status message.
4812 This allows the remote stub to send only the registers that GDB
4813 needs to make a quick decision about single-stepping or conditional
4814 breakpoints, eliminating the need to fetch the entire register set for
4815 each instruction being stepped through.
4817 The GDB remote serial protocol now implements a write-through cache for
4818 registers, only re-reading the registers if the target has run.
4820 There is also a new remote serial stub for SPARC processors. You can
4821 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4822 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4823 processor with a serial port.
4827 Configure.in files have become much easier to read and modify. A new
4828 `table driven' format makes it more obvious what configurations are
4829 supported, and what files each one uses.
4833 There is a new opcodes library which will eventually contain all of the
4834 disassembly routines and opcode tables. At present, it only contains
4835 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4836 disassembler (binutils/objdump) to share these routines.
4838 The libiberty library is now copylefted under the GNU Library General
4839 Public License. This allows more liberal use, and was done so libg++
4840 can use it. This makes no difference to GDB, since the Library License
4841 grants all the rights from the General Public License.
4845 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4846 reference to the stabs symbol info used by the debugger. It is (as far
4847 as we know) the only published document on this fascinating topic. We
4848 encourage you to read it, compare it to the stabs information on your
4849 system, and send improvements on the document in general (to
4850 bug-gdb@prep.ai.mit.edu).
4852 And, of course, many bugs have been fixed.
4855 *** Changes in GDB-4.6:
4857 * Better support for C++ function names
4859 GDB now accepts as input the "demangled form" of C++ overloaded function
4860 names and member function names, and can do command completion on such names
4861 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4862 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4863 Make use of command completion, it is your friend.
4865 GDB also now accepts a variety of C++ mangled symbol formats. They are
4866 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4867 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4868 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4869 for the list of formats.
4871 * G++ symbol mangling problem
4873 Recent versions of gcc have a bug in how they emit debugging information for
4874 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4875 directory) can be applied to gcc to fix the problem. Alternatively, if you
4876 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4877 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4878 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4881 * New 'maintenance' command
4883 All of the commands related to hacking GDB internals have been moved out of
4884 the main command set, and now live behind the 'maintenance' command. This
4885 can also be abbreviated as 'mt'. The following changes were made:
4887 dump-me -> maintenance dump-me
4888 info all-breakpoints -> maintenance info breakpoints
4889 printmsyms -> maintenance print msyms
4890 printobjfiles -> maintenance print objfiles
4891 printpsyms -> maintenance print psymbols
4892 printsyms -> maintenance print symbols
4894 The following commands are new:
4896 maintenance demangle Call internal GDB demangler routine to
4897 demangle a C++ link name and prints the result.
4898 maintenance print type Print a type chain for a given symbol
4900 * Change to .gdbinit file processing
4902 We now read the $HOME/.gdbinit file before processing the argv arguments
4903 (e.g. reading symbol files or core files). This allows global parameters to
4904 be set, which will apply during the symbol reading. The ./.gdbinit is still
4905 read after argv processing.
4907 * New hosts supported
4909 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4911 GNU/Linux support i386-unknown-linux or linux
4913 We are also including code to support the HP/PA running BSD and HPUX. This
4914 is almost guaranteed not to work, as we didn't have time to test or build it
4915 for this release. We are including it so that the more adventurous (or
4916 masochistic) of you can play with it. We also had major problems with the
4917 fact that the compiler that we got from HP doesn't support the -g option.
4920 * New targets supported
4922 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4924 * More smarts about finding #include files
4926 GDB now remembers the compilation directory for all include files, and for
4927 all files from which C is generated (like yacc and lex sources). This
4928 greatly improves GDB's ability to find yacc/lex sources, and include files,
4929 especially if you are debugging your program from a directory different from
4930 the one that contains your sources.
4932 We also fixed a bug which caused difficulty with listing and setting
4933 breakpoints in include files which contain C code. (In the past, you had to
4934 try twice in order to list an include file that you hadn't looked at before.)
4936 * Interesting infernals change
4938 GDB now deals with arbitrary numbers of sections, where the symbols for each
4939 section must be relocated relative to that section's landing place in the
4940 target's address space. This work was needed to support ELF with embedded
4941 stabs used by Solaris-2.0.
4943 * Bug fixes (of course!)
4945 There have been loads of fixes for the following things:
4946 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4947 i960, stabs, DOS(GO32), procfs, etc...
4949 See the ChangeLog for details.
4951 *** Changes in GDB-4.5:
4953 * New machines supported (host and target)
4955 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4957 SGI Irix-4.x mips-sgi-irix4 or iris4
4959 * New malloc package
4961 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4962 Mmalloc is capable of handling mutiple heaps of memory. It is also
4963 capable of saving a heap to a file, and then mapping it back in later.
4964 This can be used to greatly speedup the startup of GDB by using a
4965 pre-parsed symbol table which lives in a mmalloc managed heap. For
4966 more details, please read mmalloc/mmalloc.texi.
4970 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4971 'help info proc' for details.
4973 * MIPS ecoff symbol table format
4975 The code that reads MIPS symbol table format is now supported on all hosts.
4976 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4979 * File name changes for MS-DOS
4981 Many files in the config directories have been renamed to make it easier to
4982 support GDB on MS-DOSe systems (which have very restrictive file name
4983 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4984 environment) is close to working but has some remaining problems. Note
4985 that debugging of DOS programs is not supported, due to limitations
4986 in the ``operating system'', but it can be used to host cross-debugging.
4988 * Cross byte order fixes
4990 Many fixes have been made to support cross debugging of Sparc and MIPS
4991 targets from hosts whose byte order differs.
4993 * New -mapped and -readnow options
4995 If memory-mapped files are available on your system through the 'mmap'
4996 system call, you can use the -mapped option on the `file' or
4997 `symbol-file' commands to cause GDB to write the symbols from your
4998 program into a reusable file. If the program you are debugging is
4999 called `/path/fred', the mapped symbol file will be `./fred.syms'.
5000 Future GDB debugging sessions will notice the presence of this file,
5001 and will quickly map in symbol information from it, rather than reading
5002 the symbol table from the executable program. Using the '-mapped'
5003 option in a GDB `file' or `symbol-file' command has the same effect as
5004 starting GDB with the '-mapped' command-line option.
5006 You can cause GDB to read the entire symbol table immediately by using
5007 the '-readnow' option with any of the commands that load symbol table
5008 information (or on the GDB command line). This makes the command
5009 slower, but makes future operations faster.
5011 The -mapped and -readnow options are typically combined in order to
5012 build a `fred.syms' file that contains complete symbol information.
5013 A simple GDB invocation to do nothing but build a `.syms' file for future
5016 gdb -batch -nx -mapped -readnow programname
5018 The `.syms' file is specific to the host machine on which GDB is run.
5019 It holds an exact image of GDB's internal symbol table. It cannot be
5020 shared across multiple host platforms.
5022 * longjmp() handling
5024 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5025 siglongjmp() without losing control. This feature has not yet been ported to
5026 all systems. It currently works on many 386 platforms, all MIPS-based
5027 platforms (SGI, DECstation, etc), and Sun3/4.
5031 Preliminary work has been put in to support the new Solaris OS from Sun. At
5032 this time, it can control and debug processes, but it is not capable of
5037 As always, many many bug fixes. The major areas were with g++, and mipsread.
5038 People using the MIPS-based platforms should experience fewer mysterious
5039 crashes and trashed symbol tables.
5041 *** Changes in GDB-4.4:
5043 * New machines supported (host and target)
5045 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5047 BSD Reno on Vax vax-dec-bsd
5048 Ultrix on Vax vax-dec-ultrix
5050 * New machines supported (target)
5052 AMD 29000 embedded, using EBMON a29k-none-none
5056 GDB continues to improve its handling of C++. `References' work better.
5057 The demangler has also been improved, and now deals with symbols mangled as
5058 per the Annotated C++ Reference Guide.
5060 GDB also now handles `stabs' symbol information embedded in MIPS
5061 `ecoff' symbol tables. Since the ecoff format was not easily
5062 extensible to handle new languages such as C++, this appeared to be a
5063 good way to put C++ debugging info into MIPS binaries. This option
5064 will be supported in the GNU C compiler, version 2, when it is
5067 * New features for SVR4
5069 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5070 shared libraries. Debugging dynamically linked programs should present
5071 only minor differences from debugging statically linked programs.
5073 The `info proc' command will print out information about any process
5074 on an SVR4 system (including the one you are debugging). At the moment,
5075 it prints the address mappings of the process.
5077 If you bring up GDB on another SVR4 system, please send mail to
5078 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5080 * Better dynamic linking support in SunOS
5082 Reading symbols from shared libraries which contain debugging symbols
5083 now works properly. However, there remain issues such as automatic
5084 skipping of `transfer vector' code during function calls, which
5085 make it harder to debug code in a shared library, than to debug the
5086 same code linked statically.
5090 GDB is now using the latest `getopt' routines from the FSF. This
5091 version accepts the -- prefix for options with long names. GDB will
5092 continue to accept the old forms (-option and +option) as well.
5093 Various single letter abbreviations for options have been explicity
5094 added to the option table so that they won't get overshadowed in the
5095 future by other options that begin with the same letter.
5099 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5100 Many assorted bugs have been handled. Many more remain to be handled.
5101 See the various ChangeLog files (primarily in gdb and bfd) for details.
5104 *** Changes in GDB-4.3:
5106 * New machines supported (host and target)
5108 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5109 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5110 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5112 * Almost SCO Unix support
5114 We had hoped to support:
5115 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5116 (except for core file support), but we discovered very late in the release
5117 that it has problems with process groups that render gdb unusable. Sorry
5118 about that. I encourage people to fix it and post the fixes.
5120 * Preliminary ELF and DWARF support
5122 GDB can read ELF object files on System V Release 4, and can handle
5123 debugging records for C, in DWARF format, in ELF files. This support
5124 is preliminary. If you bring up GDB on another SVR4 system, please
5125 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5130 GDB now uses the latest `readline' library. One user-visible change
5131 is that two tabs will list possible command completions, which previously
5132 required typing M-? (meta-question mark, or ESC ?).
5136 The `stepi' bug that many of you noticed has been squashed.
5137 Many bugs in C++ have been handled. Many more remain to be handled.
5138 See the various ChangeLog files (primarily in gdb and bfd) for details.
5140 * State of the MIPS world (in case you wondered):
5142 GDB can understand the symbol tables emitted by the compilers
5143 supplied by most vendors of MIPS-based machines, including DEC. These
5144 symbol tables are in a format that essentially nobody else uses.
5146 Some versions of gcc come with an assembler post-processor called
5147 mips-tfile. This program is required if you want to do source-level
5148 debugging of gcc-compiled programs. I believe FSF does not ship
5149 mips-tfile with gcc version 1, but it will eventually come with gcc
5152 Debugging of g++ output remains a problem. g++ version 1.xx does not
5153 really support it at all. (If you're lucky, you should be able to get
5154 line numbers and stack traces to work, but no parameters or local
5155 variables.) With some work it should be possible to improve the
5158 When gcc version 2 is released, you will have somewhat better luck.
5159 However, even then you will get confusing results for inheritance and
5162 We will eventually provide full debugging of g++ output on
5163 DECstations. This will probably involve some kind of stabs-in-ecoff
5164 encapulation, but the details have not been worked out yet.
5167 *** Changes in GDB-4.2:
5169 * Improved configuration
5171 Only one copy of `configure' exists now, and it is not self-modifying.
5172 Porting BFD is simpler.
5176 The `step' and `next' commands now only stop at the first instruction
5177 of a source line. This prevents the multiple stops that used to occur
5178 in switch statements, for-loops, etc. `Step' continues to stop if a
5179 function that has debugging information is called within the line.
5183 Lots of small bugs fixed. More remain.
5185 * New host supported (not target)
5187 Intel 386 PC clone running Mach i386-none-mach
5190 *** Changes in GDB-4.1:
5192 * Multiple source language support
5194 GDB now has internal scaffolding to handle several source languages.
5195 It determines the type of each source file from its filename extension,
5196 and will switch expression parsing and number formatting to match the
5197 language of the function in the currently selected stack frame.
5198 You can also specifically set the language to be used, with
5199 `set language c' or `set language modula-2'.
5203 GDB now has preliminary support for the GNU Modula-2 compiler,
5204 currently under development at the State University of New York at
5205 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5206 continue through the fall of 1991 and into 1992.
5208 Other Modula-2 compilers are currently not supported, and attempting to
5209 debug programs compiled with them will likely result in an error as the
5210 symbol table is read. Feel free to work on it, though!
5212 There are hooks in GDB for strict type checking and range checking,
5213 in the `Modula-2 philosophy', but they do not currently work.
5217 GDB can now write to executable and core files (e.g. patch
5218 a variable's value). You must turn this switch on, specify
5219 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5220 by assigning a new value to a variable. Modifications take
5223 * Automatic SunOS shared library reading
5225 When you run your program, GDB automatically determines where its
5226 shared libraries (if any) have been loaded, and reads their symbols.
5227 The `share' command is no longer needed. This also works when
5228 examining core files.
5232 You can specify the number of lines that the `list' command shows.
5235 * New machines supported (host and target)
5237 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5238 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5239 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5241 * New hosts supported (not targets)
5243 IBM RT/PC: romp-ibm-aix or rtpc
5245 * New targets supported (not hosts)
5247 AMD 29000 embedded with COFF a29k-none-coff
5248 AMD 29000 embedded with a.out a29k-none-aout
5249 Ultracomputer remote kernel debug a29k-nyu-kern
5251 * New remote interfaces
5257 *** Changes in GDB-4.0:
5261 Wide output is wrapped at good places to make the output more readable.
5263 Gdb now supports cross-debugging from a host machine of one type to a
5264 target machine of another type. Communication with the target system
5265 is over serial lines. The ``target'' command handles connecting to the
5266 remote system; the ``load'' command will download a program into the
5267 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5268 also supports debugging of realtime processes running under VxWorks,
5269 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5270 stub on the target system.
5272 New CPUs supported include the AMD 29000 and Intel 960.
5274 GDB now reads object files and symbol tables via a ``binary file''
5275 library, which allows a single copy of GDB to debug programs of multiple
5276 object file types such as a.out and coff.
5278 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5279 refcard.dvi and refcard.ps are available to format it).
5282 * Control-Variable user interface simplified
5284 All variables that control the operation of the debugger can be set
5285 by the ``set'' command, and displayed by the ``show'' command.
5287 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5288 ``Show prompt'' produces the response:
5289 Gdb's prompt is new-gdb=>.
5291 What follows are the NEW set commands. The command ``help set'' will
5292 print a complete list of old and new set commands. ``help set FOO''
5293 will give a longer description of the variable FOO. ``show'' will show
5294 all of the variable descriptions and their current settings.
5296 confirm on/off: Enables warning questions for operations that are
5297 hard to recover from, e.g. rerunning the program while
5298 it is already running. Default is ON.
5300 editing on/off: Enables EMACS style command line editing
5301 of input. Previous lines can be recalled with
5302 control-P, the current line can be edited with control-B,
5303 you can search for commands with control-R, etc.
5306 history filename NAME: NAME is where the gdb command history
5307 will be stored. The default is .gdb_history,
5308 or the value of the environment variable
5311 history size N: The size, in commands, of the command history. The
5312 default is 256, or the value of the environment variable
5315 history save on/off: If this value is set to ON, the history file will
5316 be saved after exiting gdb. If set to OFF, the
5317 file will not be saved. The default is OFF.
5319 history expansion on/off: If this value is set to ON, then csh-like
5320 history expansion will be performed on
5321 command line input. The default is OFF.
5323 radix N: Sets the default radix for input and output. It can be set
5324 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5325 in the current radix, so "set radix 10" is always a no-op.
5327 height N: This integer value is the number of lines on a page. Default
5328 is 24, the current `stty rows'' setting, or the ``li#''
5329 setting from the termcap entry matching the environment
5332 width N: This integer value is the number of characters on a line.
5333 Default is 80, the current `stty cols'' setting, or the ``co#''
5334 setting from the termcap entry matching the environment
5337 Note: ``set screensize'' is obsolete. Use ``set height'' and
5338 ``set width'' instead.
5340 print address on/off: Print memory addresses in various command displays,
5341 such as stack traces and structure values. Gdb looks
5342 more ``symbolic'' if you turn this off; it looks more
5343 ``machine level'' with it on. Default is ON.
5345 print array on/off: Prettyprint arrays. New convenient format! Default
5348 print demangle on/off: Print C++ symbols in "source" form if on,
5351 print asm-demangle on/off: Same, for assembler level printouts
5354 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5357 * Support for Epoch Environment.
5359 The epoch environment is a version of Emacs v18 with windowing. One
5360 new command, ``inspect'', is identical to ``print'', except that if you
5361 are running in the epoch environment, the value is printed in its own
5365 * Support for Shared Libraries
5367 GDB can now debug programs and core files that use SunOS shared libraries.
5368 Symbols from a shared library cannot be referenced
5369 before the shared library has been linked with the program (this
5370 happens after you type ``run'' and before the function main() is entered).
5371 At any time after this linking (including when examining core files
5372 from dynamically linked programs), gdb reads the symbols from each
5373 shared library when you type the ``sharedlibrary'' command.
5374 It can be abbreviated ``share''.
5376 sharedlibrary REGEXP: Load shared object library symbols for files
5377 matching a unix regular expression. No argument
5378 indicates to load symbols for all shared libraries.
5380 info sharedlibrary: Status of loaded shared libraries.
5385 A watchpoint stops execution of a program whenever the value of an
5386 expression changes. Checking for this slows down execution
5387 tremendously whenever you are in the scope of the expression, but is
5388 quite useful for catching tough ``bit-spreader'' or pointer misuse
5389 problems. Some machines such as the 386 have hardware for doing this
5390 more quickly, and future versions of gdb will use this hardware.
5392 watch EXP: Set a watchpoint (breakpoint) for an expression.
5394 info watchpoints: Information about your watchpoints.
5396 delete N: Deletes watchpoint number N (same as breakpoints).
5397 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5398 enable N: Re-enables watchpoint number N (same as breakpoints).
5401 * C++ multiple inheritance
5403 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5406 * C++ exception handling
5408 Gdb now supports limited C++ exception handling. Besides the existing
5409 ability to breakpoint on an exception handler, gdb can breakpoint on
5410 the raising of an exception (before the stack is peeled back to the
5413 catch FOO: If there is a FOO exception handler in the dynamic scope,
5414 set a breakpoint to catch exceptions which may be raised there.
5415 Multiple exceptions (``catch foo bar baz'') may be caught.
5417 info catch: Lists all exceptions which may be caught in the
5418 current stack frame.
5421 * Minor command changes
5423 The command ``call func (arg, arg, ...)'' now acts like the print
5424 command, except it does not print or save a value if the function's result
5425 is void. This is similar to dbx usage.
5427 The ``up'' and ``down'' commands now always print the frame they end up
5428 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5429 frames without printing.
5431 * New directory command
5433 'dir' now adds directories to the FRONT of the source search path.
5434 The path starts off empty. Source files that contain debug information
5435 about the directory in which they were compiled can be found even
5436 with an empty path; Sun CC and GCC include this information. If GDB can't
5437 find your source file in the current directory, type "dir .".
5439 * Configuring GDB for compilation
5441 For normal use, type ``./configure host''. See README or gdb.texinfo
5444 GDB now handles cross debugging. If you are remotely debugging between
5445 two different machines, type ``./configure host -target=targ''.
5446 Host is the machine where GDB will run; targ is the machine
5447 where the program that you are debugging will run.